ORCID Profile
0000-0002-6759-2560
Current Organisations
University of Nottingham
,
Intercollegiate Board in Orthopaedics
,
National University Health System
,
Royal College of Surgeons of Edinburgh
,
All India Institute of Medical Sciences
,
University of Queensland
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Neurosciences | Cellular Nervous System | Central Nervous System | Biochemistry and cell biology | Cell development proliferation and death | Central nervous system | Genomics and transcriptomics |
Nervous System and Disorders | Expanding Knowledge in the Biological Sciences | Child Health | Mental Health |
Publisher: Wiley
Date: 15-11-2019
DOI: 10.1002/AJMG.C.31747
Abstract: The nuclear factor one (NFI) site-specific DNA-binding proteins represent a family of transcription factors that are important for the development of multiple organ systems, including the brain. During brain development in mice, the expression patterns of Nfia, Nfib, and Nfix overlap, and knockout mice for each of these exhibit overlapping brain defects, including megalencephaly, dysgenesis of the corpus callosum, and enlarged ventricles, which implies a common but not redundant function in brain development. In line with these models, human phenotypes caused by haploinsufficiency of NFIA, NFIB, and NFIX display significant overlap, sharing neurodevelopmental deficits, macrocephaly, brain anomalies, and variable somatic overgrowth. Other anomalies may be present depending on the NFI gene involved. The possibility of variants in NFI genes should therefore be considered in in iduals with intellectual disability and brain overgrowth, with in idual NFI-related conditions being differentiated from one another by additional signs and symptoms. The exception is provided by specific NFIX variants that act in a dominant negative manner, as these cause a recognizable entity with more severe cognitive impairment and marked bone dysplasia, Marshall-Smith syndrome. NFIX duplications are associated with a phenotype opposite to that of haploinsufficiency, characterized by short stature, small head circumference, and delayed bone age. The spectrum of NFI-related disorders will likely be further expanded, as larger cohorts are assessed.
Publisher: Springer Science and Business Media LLC
Date: 09-12-2020
DOI: 10.1038/S41525-020-00162-9
Abstract: USP9X is an X-chromosome gene that escapes X-inactivation. Loss or compromised function of USP9X leads to neurodevelopmental disorders in males and females. While males are impacted primarily by hemizygous partial loss-of-function missense variants, in females de novo heterozygous complete loss-of-function mutations predominate, and give rise to the clinically recognisable USP9X -female syndrome. Here we provide evidence of the contribution of USP9X missense and small in-frame deletion variants in USP9X -female syndrome also. We scrutinise the pathogenicity of eleven such variants, ten of which were novel. Combined application of variant prediction algorithms, protein structure modelling, and assessment under clinically relevant guidelines universally support their pathogenicity. The core phenotype of this cohort overlapped with previous descriptions of USP9X -female syndrome, but exposed heightened variability. Aggregate phenotypic information of 35 currently known females with predicted pathogenic variation in USP9X reaffirms the clinically recognisable USP9X -female syndrome, and highlights major differences when compared to USP9X -male associated neurodevelopmental disorders.
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.YDBIO.2017.10.019
Abstract: During mouse spinal cord development, ventricular zone progenitor cells transition from producing neurons to producing glia at approximately embryonic day 11.5, a process known as the gliogenic switch. The transcription factors Nuclear Factor I (NFI) A and B initiate this developmental transition, but the contribution of a third NFI member, NFIX, remains unknown. Here, we reveal that ventricular zone progenitor cells within the spinal cord express NFIX after the onset of NFIA and NFIB expression, and after the gliogenic switch has occurred. Mice lacking NFIX exhibit normal neurogenesis within the spinal cord, and, while early astrocytic differentiation proceeds normally, aspects of terminal astrocytic differentiation are impaired. Finally, we report that, in the absence of Nfia or Nfib, there is a marked reduction in the spinal cord expression of NFIX, and that NFIB can transcriptionally activate Nfix expression in vitro. These data demonstrate that NFIX is part of the downstream transcriptional program through which NFIA and NFIB coordinate gliogenesis within the spinal cord. This hierarchical organisation of NFI protein expression and function during spinal cord gliogenesis reveals a previously unrecognised auto-regulatory mechanism within this gene family.
Publisher: Springer Science and Business Media LLC
Date: 25-02-2015
Publisher: Wiley
Date: 02-08-2017
DOI: 10.1002/DVDY.24545
Abstract: Type 1 adult hippoc al neural stem cells (AH-NSCs) continue to generate neurons throughout life, albeit at a very low rate. The relative quiescence of this population of cells has led to many studies investigating factors that may increase their ision. Current methods of identifying iding AH-NSCs in vivo require the identification and tracing of radial processes back to nuclei within the subgranular zone. However, caveats to this approach include the time-intensive nature of identifying AH-NSCs with such a process, as well as the fact that this approach ignores the relatively more active population of horizontally oriented AH-NSCs that also reside in the subgranular zone. Here we describe, and then verify using Hes5::GFP mice, that labeling for the cell cycle marker Ki67 and selection against the intermediate progenitor cell marker TBR2 (Ki67 These findings provide a simple and accurate way to quantify iding AH-NSCs in vivo using a morphology-independent approach that will facilitate studies into neurogenesis within the hippoc al stem cell niche of the adult brain. Developmental Dynamics 247:194-200, 2018. © 2017 Wiley Periodicals, Inc.
Publisher: Wiley
Date: 08-02-2017
DOI: 10.1002/IJC.30603
Abstract: Tumour heterogeneity poses a distinct obstacle to therapeutic intervention. While the initiation of tumours across various physiological systems is frequently associated with signature mutations in genes that drive proliferation and bypass senescence, increasing evidence suggests that tumour progression and clonal ersity is driven at an epigenetic level. The tumour microenvironment plays a key role in driving ersity as cells adapt to demands imposed during tumour growth, and is thought to drive certain subpopulations back to a stem cell-like state. This stem cell-like phenotype primes tumour cells to react to external cues via the use of developmental pathways that facilitate changes in proliferation, migration and invasion. Because the dynamism of this stem cell-like state requires constant chromatin remodelling and rapid alterations at regulatory elements, it is of great therapeutic interest to identify the cell-intrinsic factors that confer these epigenetic changes that drive tumour progression. The nuclear factor one (NFI) family are transcription factors that play an important role in the development of many mammalian organ systems. While all four family members have been shown to act as either oncogenes or tumour suppressors across various cancer models, evidence has emerged implicating them as key epigenetic regulators during development and within tumours. Notably, NFIs have also been shown to regulate chromatin accessibility at distal regulatory elements that drive tumour cell dissemination and metastasis. Here we summarize the role of the NFIs in cancer, focusing largely on the potential mechanisms associated with chromatin remodelling and epigenetic modulation of gene expression.
Publisher: Springer Science and Business Media LLC
Date: 25-02-2014
DOI: 10.1245/S10434-014-3569-X
Abstract: Intraoperative cell salvage (IOCS) has been used in musculoskeletal surgery extensively. However, it has never found its place in musculoskeletal oncologic surgery. We have conducted the first-ever study to evaluate the feasibility of IOCS in combination with a leucocyte-depletion filter (LDF) in metastatic spine tumor surgery. This was to pave the path for use of IOCS-LDF in musculoskeletal oncologic surgery. Patients with a known primary epithelial tumor, who were offered surgery for metastatic spinal disease, were recruited. Blood s les were collected at three different stages during the surgery: from the operative field before IOCS processing, after IOCS processing, and after IOCS-LDF processing. Three separate s les (5 mL each) were taken at each stage. S les were examined using immunohistochemical monoclonal antibodies to identify tumor cells of epithelial origin. Of 30 patients in the study, 6 were excluded for not fulfilling the inclusion criteria, leaving 24 patients. Malignant tumor cells were detected in the s les from the operative field before IOCS processing in eight patients and in the s les from the transfusion bag after IOCS processing in three patients. No viable malignant cell was detectable in any of the blood s les after passage through both IOCS and LDF. The findings support the notion that the IOCS-LDF combination works effectively in eliminating tumor cells from salvaged blood, so this technique can be applied successfully in spine tumor surgery. This concept can then further be extended to whole musculoskeletal tumor surgery and other oncologic surgeries with further appropriate clinical studies.
Publisher: Elsevier BV
Date: 08-2021
Publisher: Springer Science and Business Media LLC
Date: 11-2017
DOI: 10.1007/S10735-016-9702-3
Abstract: Endothelial cells form a critical component of the coronary vasculature, yet the factors regulating their development remain poorly defined. Here we reveal a novel role for the transmembrane protein CRIM1 in mediating cardiac endothelial cell development. In the absence of Crim1 in vivo, the coronary vasculature is malformed, the number of endothelial cells reduced, and the canonical BMP pathway dysregulated. Moreover, we reveal that CRIM1 can bind IGFs, and regulate IGF signalling within endothelial cells. Finally, loss of CRIM1 from human cardiac endothelial cells results in misregulation of endothelial genes, predicted by pathway analysis to be involved in an increased inflammatory response and cytolysis, reminiscent of endothelial cell dysfunction in cardiovascular disease pathogenesis. Collectively, these findings implicate CRIM1 in endothelial cell development and homeostasis in the coronary vasculature.
Publisher: Springer Science and Business Media LLC
Date: 15-05-2017
Publisher: EMBO
Date: 13-06-2022
Publisher: Springer Science and Business Media LLC
Date: 31-05-2021
DOI: 10.1038/S41380-021-01149-3
Abstract: Neural stem cells in the human subependymal zone (SEZ) generate neuronal progenitor cells that can differentiate and integrate as inhibitory interneurons into cortical and subcortical brain regions yet the extent of adult neurogenesis remains unexplored in schizophrenia and bipolar disorder. We verified the existence of neurogenesis across the lifespan by chartering transcriptional alterations (2 days-103 years, n = 70) and identifying cells indicative of different stages of neurogenesis in the human SEZ. Expression of most neural stem and neuronal progenitor cell markers decreased during the first postnatal years and remained stable from childhood into ageing. We next discovered reduced neural stem and neuronal progenitor cell marker expression in the adult SEZ in schizophrenia and bipolar disorder compared to controls (n = 29-32 per group). RNA sequencing identified increased expression of the macrophage marker CD163 as the most significant molecular change in schizophrenia. CD163
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.SPINEE.2016.09.009
Abstract: Osteoblastoma is rare and accounts for 3% of all benign tumors and 1% of all bone tumors. The spine is the most common site of occurrence, constituting 32% to 45% of all osteoblastomas. It has a strong predilection for the posterior elements, most often occurring in the lumbar spine. In this case report, we describe an unusual presentation of spinal osteoblastoma presenting as thoracic T9 vertebra plana in a 20-year-old female. She presented with discomfort over the midback with unsteadiness of gait. The patient underwent detailed investigations including computed tomography (CT), magnetic resonance imaging, and CT-guided biopsy. To our knowledge, this is the first case report of vertebra plana due to spinal osteoblastoma in the English literature. The patient successfully underwent posterior decompression of T9 with laminectomy followed by minimally invasive surgery posterior instrumentation from T7 to T11. Histopathology of the intraoperative specimen was consistent with osteoblastoma. The patient had an uneventful postoperative recovery and no evidence of tumor recurrence could be demonstrated on positron emission tomography scan at 15 months' follow-up. In conclusion, the differential diagnosis for vertebra plana is extensive and we add spinal osteoblastoma as another etiology to the existing list. Diagnosis and treatment of vertebra plana involve multimodality radiological imaging, and careful histological and surgical evaluation to identify the underlying etiology.
Publisher: Springer Science and Business Media LLC
Date: 23-11-2017
DOI: 10.1007/S00429-016-1340-8
Abstract: Transcription factors from the nuclear factor one (NFI) family have been shown to play a central role in regulating neural progenitor cell differentiation within the embryonic and post-natal brain. NFIA and NFIB, for instance, promote the differentiation and functional maturation of granule neurons within the cerebellum. Mice lacking Nfix exhibit delays in the development of neuronal and glial lineages within the cerebellum, but the cell-type-specific expression of this transcription factor remains undefined. Here, we examined the expression of NFIX, together with various cell-type-specific markers, within the developing and adult cerebellum using both chromogenic immunohistochemistry and co-immunofluorescence labelling and confocal microscopy. In embryos, NFIX was expressed by progenitor cells within the rhombic lip and ventricular zone. After birth, progenitor cells within the external granule layer, as well as migrating and mature granule neurons, expressed NFIX. Within the adult cerebellum, NFIX displayed a broad expression profile, and was evident within granule cells, Bergmann glia, and interneurons, but not within Purkinje neurons. Furthermore, transcriptomic profiling of cerebellar granule neuron progenitor cells showed that multiple splice variants of Nfix are expressed within this germinal zone of the post-natal brain. Collectively, these data suggest that NFIX plays a role in regulating progenitor cell biology within the embryonic and post-natal cerebellum, as well as an ongoing role within multiple neuronal and glial populations within the adult cerebellum.
Publisher: Elsevier BV
Date: 05-2012
DOI: 10.1016/J.YDBIO.2012.02.004
Abstract: The Slit molecules are chemorepulsive ligands that regulate axon guidance at the midline of both vertebrates and invertebrates. In mammals, there are three Slit genes, but only Slit2 has been studied in any detail with regard to mammalian brain commissure formation. Here, we sought to understand the relative contributions that Slit proteins make to the formation of the largest brain commissure, the corpus callosum. Slit ligands bind Robo receptors, and previous studies have shown that Robo1(-/-) mice have defects in corpus callosum development. However, whether the Slit genes signal exclusively through Robo1 during callosal formation is unclear. To investigate this, we compared the development of the corpus callosum in both Slit2(-/-) and Robo1(-/-) mice using diffusion magnetic resonance imaging. This analysis demonstrated similarities in the phenotypes of these mice, but crucially also highlighted subtle differences, particularly with regard to the guidance of post-crossing axons. Analysis of single mutations in Slit family members revealed corpus callosum defects (but not complete agenesis) in 100% of Slit2(-/-) mice and 30% of Slit3(-/-) mice, whereas 100% of Slit1(-/-) Slit2(-/-) mice displayed complete agenesis of the corpus callosum. These results revealed a role for Slit1 in corpus callosum development, and demonstrated that Slit2 was necessary but not sufficient for midline crossing in vivo. However, co-culture experiments utilising Robo1(-/-) tissue versus Slit2 expressing cell blocks demonstrated that Slit2 was sufficient for the guidance activity mediated by Robo1 in pre-crossing neocortical axons. This suggested that Slit1 and Slit3 might also be involved in regulating other mechanisms that allow the corpus callosum to form, such as the establishment of midline glial populations. Investigation of this revealed defects in the development and dorso-ventral positioning of the indusium griseum glia in multiple Slit mutants. These findings indicate that Slits regulate callosal development via both classical chemorepulsive mechanisms, and via a novel role in mediating the correct positioning of midline glial populations. Finally, our data also indicate that some of the roles of Slit proteins at the midline may be independent of Robo signalling, suggestive of additional receptors regulating Slit signalling during development.
Publisher: Frontiers Media SA
Date: 11-09-2020
Publisher: Cold Spring Harbor Laboratory
Date: 15-08-2202
DOI: 10.1101/2022.08.12.503759
Abstract: Identification of cell types using single cell RNA-seq (scRNA-seq) is revolutionising the study of multicellular organisms. However, typical scRNA-seq analysis often involves post hoc manual curation to ensure clusters are transcriptionally distinct, which is time-consuming, error-prone, and irreproducible. To overcome these obstacles, we developed Cytocipher , a bioinformatics method and scverse compatible software package that statistically determines significant clusters. Application of Cytocipher to normal tissue, development, disease, and large-scale atlas data reveals the broad applicability and power of Cytocipher to generate biological insights in numerous contexts. This included the identification of cell types not previously described in the datasets analyzed, such as CD8+ T cell subtypes in human peripheral blood mononuclear cells cell lineage intermediate states during mouse pancreas development and subpopulations of luminal epithelial cells over-represented in prostate cancer. Cytocipher also scales to large datasets with high test performance, as shown by application to the Tabula Sapiens Atlas representing ,000 cells. Cytocipher is a novel and generalisable method that statistically determines transcriptionally distinct and programmatically reproducible clusters from single cell data. Cytocipher is available at github.com/BradBalderson/Cytocipher .
Publisher: Springer Science and Business Media LLC
Date: 19-07-2015
DOI: 10.1007/S00586-015-4112-X
Abstract: To evaluate the feasibility of using intraoperative cell salvage (IOCS) in combination with leucocyte depletion filter (LDF) in eliminating tumour cells from blood salvaged during metastatic spine tumour surgery (MSTS). This is with the view to pave the path for use of IOCS-LDF in MSTS and musculoskeletal oncological surgery. Sixty consecutive patients with known primary epithelial tumour, who were offered surgery for metastatic spine disease at our university hospital, were recruited. Blood s les were collected at three different stages during surgery: from operative field prior to IOCS processing, after IOCS processing and after IOCS-LDF processing. Three separate s les (5 ml each) were taken at each stage. S les were examined by cell block technique using immunohistochemical monoclonal antibodies to identify tumour cells of epithelial origin in the s les. Of 60 patients, ten were excluded for not fulfilling the inclusion criteria leaving 50 patients. Malignant tumour cells were detected in the s les from operative field prior to IOCS processing in 24 patients and in the s les from the transfusion bag post-IOCS processing in 4 patients. No viable malignant cells were detectable in any of the blood s les after passage through both IOCS and LDF. The findings support the notion that IOCS-LDF combination works effectively in eliminating tumour cells from salvaged blood so this technique can possibly be applied in MSTS and even musculoskeletal oncological surgery. This concept can then be extended to other oncological surgeries in general with further appropriate clinical studies.
Publisher: Elsevier BV
Date: 12-2006
Publisher: Springer Science and Business Media LLC
Date: 07-03-2016
DOI: 10.1007/S00586-016-4478-4
Abstract: This study aimed at evaluating our hypothesis that tumour cells, which pass through the intraoperative cell salvage (IOCS) machine, lose viability due to possible injury to the cell membrane during centrifugation and filtration, enabling safe reinfusion even without filtration. Thirteen patients who underwent metastatic spine tumour surgery (MSTS) at our institution were recruited. Blood s les (5 ml each) were collected at five different stages during surgery, namely, stage A and B: from patients' vein during induction and at the time of maximum tumour manipulation stage C, D and E: from the operative blood prior to IOCS processing, after IOCS processing and after IOCS-LDF (leucocyte depletion filter) processing, respectively. The s les were then analysed for viability of tumour cells using microwell-based culture. The median age of the patients was 65 years (range 37-77 years). The most common primary tumour was lung, followed by breast, hepatocellular and renal cell carcinoma. The median blood loss was 680 ml (range 300-1500 ml). Analysis of cultured blood s les showed that CTC-containing clusters were developed from some s les before IOCS-LDF processing (stage A: three patients, stage B: three patients and stage C: one patient). None of the s les from stages D and E generated clusters after culture, suggesting the absence of viable cancer cells after IOCS processing. The salvaged blood may contain some tumour cells after processing with IOCS machine, but these cells are damaged and hence unable to replicate and unlikely to metastasise. The results of this study support the hypothesis that salvaged blood in MSTS is safe for transfusion.
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.EJSO.2017.05.006
Abstract: The advent of minimally invasive surgery (MIS) in the surgical management armamentarium and stereotactic radiosurgery in the domain of radiotherapy, has led to a major evolution in treatment of metastatic spine disease (MSD). We reviewed the recent literature to discuss evolution from open to MIS approaches in MSD and the concurrent evolution in radiotherapy. This will provide a sound base for further development and understanding of treatment paradigms in MSD. Literature review showed that evolution of surgery can be traced from inappropriate open surgery (i.e. laminectomy) to appropriate open (i.e. posterior instrumentation and decompression) and further to minimally invasive surgery. This transition was concurrent with the introduction of radiotherapy and its evolution in management of MSD. Evidence shows that presently, the best clinical outcomes are achieved by surgery with timely postoperative radiotherapy. To make surgery an appealing choice in MSD, surgical morbidity needs to be minimized when planning postoperative oncological treatment. MIS approaches have advantages such as early wound healing enabling early introduction of radiotherapy, reduced intraoperative blood loss and shortened hospital stay. Pain reduction and neurological improvement are comparable to open surgery. A multidisciplinary team approach including spinal surgeons, medical & radiation oncologists is mandatory, as the treatment options are constantly evolving. Advancement in radiotherapy with introduction of MIS can be a game-changer in MSD due to reduced peri-operative morbidity, allowing earlier postoperative radiotherapy/chemotherapy. We also provide our treatment algorithm which relies on clinical presentation and radiological appearance of spinal cord compression, providing an overview of treatment strategy.
Publisher: The Company of Biologists
Date: 15-12-2016
DOI: 10.1242/DEV.140681
Abstract: During forebrain development, radial glia generate neurons through the production of intermediate progenitor cells (IPCs). The production of IPCs is a central tenet underlying the generation of the appropriate number of cortical neurons, but the transcriptional logic underpinning this process remains poorly defined. Here, we examined IPC production using mice lacking the transcription factor nuclear factor I/X (Nfix). We show that Nfix deficiency delays IPC production and prolongs the neurogenic window, resulting in an increased number of neurons in the postnatal forebrain. Loss of additional Nfi alleles (Nfib) resulted in a severe delay in IPC generation while, conversely, overexpression of NFIX led to precocious IPC generation. Mechanistically, analyses of microarray and ChIP-seq datasets, coupled with the investigation of spindle orientation during radial glial cell ision, revealed that NFIX promotes the generation of IPCs via the transcriptional upregulation of inscuteable (Insc). These data thereby provide novel insights into the mechanisms controlling the timely transition of radial glia into IPCs during forebrain development.
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.SPINEE.2014.06.001
Abstract: The decision for operative treatment of patients with spinal metastases is dependent on the patient's predicted survival. Tokuhashi, Tomita, Bauer, and Oswestry scores have been devised for survival prediction however, none of these systems have been evaluated in nasopharyngeal carcinoma (NPC). To investigate the accuracy of these scoring systems in predicting survival and to identify prognostic factors for survival of the patients with spinal metastases from NPC. Retrospective analysis of the patients with spinal metastases from NPC who were treated in our institution. The study included 87 patients with spinal metastases from NPC. The primary outcome measure was the survival time of these patients. The potential prognostic factors that are known to influence survival such as general condition, extraspinal bone metastases, vertebral bone metastases, visceral metastases, and neurologic assessment based on Frankel score were also studied. The predicted survival according to the four scoring systems were calculated and labeled as "A" scores. These patients were then rescored by assigning NPC as a good prognostic tumor and labeled as "B" scores. The predicted survival of scores A and B were compared with actual survival. Potential prognostic factors of survival were investigated using univariate and multivariate Cox regression analyses. For all scoring systems, Kaplan-Meier survival estimates and log-rank tests were done the predictive values were calculated using postestimation after Cox regression analyses. The median overall survival for the whole cohort was 13 (range 1-120) months. In multivariate analysis, general condition (p<.01), visceral metastases (p<.01), and vertebral metastases (p<.01) showed significant association with survival. The absolute score of all scoring systems was significantly associated with actual survival, which extended to the different prognostic subgroups of each scoring systems. Log-rank test revealed significant differences in survival between the different prognostic subgroups of all scoring systems (p<.01). Predictive value of survival by modified Tokuhashi score was the highest among all four scoring systems. Patients with spinal metastases from NPC have relatively good survival prognosis. All four scoring systems could be used to prognosticate these patients. The modified Tokuhashi score is the best in doing so.
Publisher: Annual Reviews
Date: 11-2004
DOI: 10.1146/ANNUREV.CELLBIO.20.010403.111746
Abstract: ▪ Abstract The cell body has classically been considered the exclusive source of axonal proteins. However, significant evidence has accumulated recently to support the view that protein synthesis can occur in axons themselves, remote from the cell body. Indeed, local translation in axons may be integral to aspects of synaptogenesis, long-term facilitation, and memory storage in invertebrate axons, and for growth cone navigation in response to environmental stimuli in developing vertebrate axons. Here we review the evidence supporting mRNA translation in axons and discuss the potential roles that local protein synthesis may play during development and subsequent neuronal function. We advance the view that local translation provides a rapid supply of nascent proteins in restricted axonal compartments that can potentially underlie long-term responses to transient stimuli.
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.JOCN.2017.05.021
Abstract: We conducted a retrospective review of 221 patients, who underwent spinal oncologic surgery at a tertiary university hospital between 2005 and 2014 in order to identify and validate factors that influence the impact of preoperative embolization of spinal tumours on outcome measures of blood loss and transfusion requirements in spinal oncologic surgery. We also focused on primary tumour type and type of spinal surgery performed. Patients' electronic and physical records were reviewed to provide demographic data, tumour characteristics, embolization techniques and surgical procedure details. These data were analysed against recorded outcome measures of blood loss (absolute volume and haemoglobin reduction) and transfusion requirements. Forty eight patients who received preoperative embolization were compared against 173 patients who did not. There was a tendency towards reduced blood loss and transfusion requirements in embolized spinal metastases from HCC and thyroid as well as primary spine tumours, though the differences were not significant. Total embolization of arterial supply to spinal tumours resulted in significantly less blood loss as compared to partial or subtotal embolization. In addition, median blood loss was lower in patients receiving a more proximal embolization and in patients who underwent surgery between 13 and 24h post-embolization despite the insignificant difference. To conclude, preoperative spinal tumour embolization is likely to be effective in reducing blood loss if a total embolization is performed 13-24h prior to the surgery. Similarly, the impact of embolization is likely to be more profound in metastases from HCC, thyroid and primary spine tumours.
Publisher: Oxford University Press (OUP)
Date: 14-11-2020
Abstract: Genetic association studies have identified many factors associated with neurodevelopmental disorders such as autism spectrum disorder (ASD). However, the way these genes shape neuroanatomical structure and connectivity is poorly understood. Recent research has focused on proteins that act as points of convergence for multiple factors, as these may provide greater insight into understanding the biology of neurodevelopmental disorders. USP9X, a deubiquitylating enzyme that regulates the stability of many ASD-related proteins, is one such point of convergence. Loss of function variants in human USP9X lead to brain malformations, which manifest as a neurodevelopmental syndrome that frequently includes ASD, but the underlying structural and connectomic abnormalities giving rise to patient symptoms is unknown. Here, we analyzed forebrain-specific Usp9x knockout mice (Usp9x−/y) to address this knowledge gap. Usp9x−/y mice displayed abnormal communication and social interaction behaviors. Moreover, the absence of Usp9x culminated in reductions to the size of multiple brain regions. Diffusion tensor magnetic resonance imaging revealed deficits in all three major forebrain commissures, as well as long-range hypoconnectivity between cortical and subcortical regions. These data identify USP9X as a key regulator of brain formation and function, and provide insights into the neurodevelopmental syndrome arising as a consequence of USP9X mutations in patients.
Publisher: Cold Spring Harbor Laboratory
Date: 08-01-2021
DOI: 10.1101/2021.01.08.425857
Abstract: Homozygous nonsense mutations in CEP55 are associated with several congenital malformations that lead to perinatal lethality suggesting that it plays a critical role in regulation of embryonic development. CEP55 has previously been studied as a critical regulator of cytokinesis predominantly in transformed cells and its deregulation is linked to carcinogenesis. However, its molecular functions during embryonic development in mammals have not been clearly defined. We have generated a Cep55 knockout (Cep55 -/- ) mouse model which demonstrated perinatal lethality associated with a wide range of neural defects. Focusing our analysis on the neocortex, we show that Cep55-/- embryos exhibited depleted neural stem rogenitor cells in the ventricular zone as a result of significantly increased cellular apoptosis. Mechanistically, we demonstrated that Cep55-loss downregulates the pGsk3β/β-Catenin/Myc axis in an Akt-dependent manner. The phenotype was recapitulated using human cerebral organoids and we could rescue the phenotype by inhibiting active Gsk3β. Additionally, we show that Cep55-loss leads to a significant reduction of ciliated cells, highlighting its novel role in regulating ciliogenesis. Collectively, our findings demonstrate a critical role of Cep55 during brain development and provide mechanistic insights that may have important implications for genetic syndromes associated with Cep55-loss.
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.YMETH.2017.09.001
Abstract: Transcription factors regulate gene expression and play an essential role in development by maintaining proliferative states, driving cellular differentiation and determining cell fate. Transcription factors are capable of regulating multiple genes over potentially long distances making target gene identification challenging. Currently available experimental approaches to detect distal interactions have multiple weaknesses that have motivated the development of computational approaches. Although an improvement over experimental approaches, existing computational approaches are still limited in their application, with different weaknesses depending on the approach. Here, we review computational approaches with a focus on data dependency, cell type specificity and usability. With the aim of identifying transcription factor target genes, we apply available approaches to typical transcription factor experimental datasets. We show that approaches are not always capable of annotating all transcription factor binding sites binding sites should be treated disparately and a combination of approaches can increase the biological relevance of the set of genes identified as targets.
Publisher: Springer Science and Business Media LLC
Date: 23-01-2020
DOI: 10.1007/S12035-020-01881-X
Abstract: Intellectual disability (ID) and autism spectrum disorder (ASD) are two of the most common neurodevelopmental disorders. Both disorders are extremely heterogenous, and only ~ 40% of reported cases have so far been attributed to genetic mutations. Of the many cellular processes that are affected, the ubiquitin system (UbS) is of particular relevance in that it can rapidly regulate multiple signaling cascades simultaneously. The UbS is a post-translational modification process that revolves around the covalent attachment of a ubiquitin moiety to a substrate, thereby influencing different elements of protein biology, including trafficking, signal transduction, and degradation. Importantly, the UbS has been implicated in regulating multiple pathophysiological pathways related to ASD and ID. This review will discuss how the UbS acts as major signaling hub in the pathogenesis of ASD and ID, raising the prospect of treating broader patient cohorts by targeting the UbS as a common point of convergence of various mutations.
Publisher: Oxford University Press (OUP)
Date: 07-2023
DOI: 10.1093/BIOINFORMATICS/BTAD435
Abstract: Identification of cell types using single-cell RNA-seq is revolutionizing the study of multicellular organisms. However, typical single-cell RNA-seq analysis often involves post hoc manual curation to ensure clusters are transcriptionally distinct, which is time-consuming, error-prone, and irreproducible. To overcome these obstacles, we developed Cytocipher, a bioinformatics method and scverse compatible software package that statistically determines significant clusters. Application of Cytocipher to normal tissue, development, disease, and large-scale atlas data reveals the broad applicability and power of Cytocipher to generate biological insights in numerous contexts. This included the identification of cell types not previously described in the datasets analysed, such as CD8+ T cell subtypes in human peripheral blood mononuclear cells cell lineage intermediate states during mouse pancreas development and subpopulations of luminal epithelial cells over-represented in prostate cancer. Cytocipher also scales to large datasets with high-test performance, as shown by application to the Tabula Sapiens Atlas representing & 000 cells. Cytocipher is a novel and generalizable method that statistically determines transcriptionally distinct and programmatically reproducible clusters from single-cell data. The software version used for this manuscript has been deposited on Zenodo (0.5281/zenodo.8089546), and is also available via github (github.com/BradBalderson/Cytocipher).
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2018
Publisher: Elsevier BV
Date: 2019
Publisher: Society for Neuroscience
Date: 17-11-2010
DOI: 10.1523/JNEUROSCI.1800-10.2010
Abstract: Cue-directed axon guidance depends partly on local translation in growth cones. Many mRNA transcripts are known to reside in developing axons, yet little is known about their subcellular distribution or, specifically, which transcripts are in growth cones. Here laser capture microdissection (LCM) was used to isolate the growth cones of retinal ganglion cell (RGC) axons of two vertebrate species, mouse and Xenopus , coupled with unbiased genomewide microarray profiling. An unexpectedly large pool of mRNAs defined predominant pathways in protein synthesis, oxidative phosphorylation, cancer, neurological disease, and signaling. Comparative profiling of “young” (pathfinding) versus “old” (target-arriving) Xenopus growth cones revealed that the number and complexity of transcripts increases dramatically with age. Many presynaptic protein mRNAs are present exclusively in old growth cones, suggesting that functionally related sets of mRNAs are targeted to growth cones in a developmentally regulated way. Remarkably, a subset of mRNAs was significantly enriched in the growth cone compared with the axon compartment, indicating that mechanisms exist to localize mRNAs selectively to the growth cone. Furthermore, some receptor transcripts (e.g., EphB4), present exclusively in old growth cones, were equally abundant in young and old cell bodies, indicating that RNA trafficking from the soma is developmentally regulated. Our findings show that the mRNA repertoire in growth cones is regulated dynamically with age and suggest that mRNA localization is tailored to match the functional demands of the growing axon tip as it transforms into the presynaptic terminal.
Publisher: Proceedings of the National Academy of Sciences
Date: 20-06-2011
Abstract: The sequential production of neurons and astrocytes from neuroepithelial precursors is a fundamental feature of central nervous system development. We report that LIM-homeodomain (LIM-HD) transcription factor Lhx2 regulates this transition in the developing hippoc us. Disrupting Lhx2 function in the embryonic hippoc us by in utero electroporation and in organotypic slice culture caused the premature production of astrocytes at stages when neurons are normally generated. Lhx2 function is therefore necessary to suppress astrogliogenesis during the neurogenic period. Furthermore, Lhx2 overexpression was sufficient to suppress astrogliogenesis and prolong the neurogenic period. We provide evidence that Lhx2 overexpression can counteract the instructive astrogliogenic effect of Notch activation. Lhx2 overexpression was also able to override and suppress the activation of the GFAP promoter by Nfia, a Notch-regulated transcription factor that is required for gliogenesis. Thus, Lhx2 appears to act as a “brake” on Notch/Nfia-mediated astrogliogenesis. This critical role for Lhx2 is spatially restricted to the hippoc us, because loss of Lhx2 function in the neocortex did not result in premature astrogliogenesis at the expense of neurogenesis. Our results therefore place Lhx2 as a central regulator of the neuron-glia cell fate decision in the hippoc us and reveal a striking regional specificity of this fundamental function within the dorsal telencephalon.
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 09-2012
Publisher: Springer Science and Business Media LLC
Date: 29-01-2016
DOI: 10.1038/SREP19832
Abstract: The epicardium has a critical role during embryonic development, contributing epicardium-derived lineages to the heart, as well as providing regulatory and trophic signals necessary for myocardial development. Crim1 is a unique trans-membrane protein expressed by epicardial and epicardially-derived cells but its role in cardiogenesis is unknown. Using knockout mouse models, we observe that loss of Crim1 leads to congenital heart defects including epicardial defects and hypoplastic ventricular compact myocardium. Epicardium-restricted deletion of Crim1 results in increased epithelial-to-mesenchymal transition and invasion of the myocardium in vivo, and an increased migration of primary epicardial cells. Furthermore, Crim1 appears to be necessary for the proliferation of epicardium-derived cells (EPDCs) and for their subsequent differentiation into cardiac fibroblasts. It is also required for normal levels of cardiomyocyte proliferation and apoptosis, consistent with a role in regulating epicardium-derived trophic factors that act on the myocardium. Mechanistically, Crim1 may also modulate key developmentally expressed growth factors such as TGFβs, as changes in the downstream effectors phospho-SMAD2 and phospho-ERK1/2 are observed in the absence of Crim1 . Collectively, our data demonstrates that Crim1 is essential for cell-autonomous and paracrine aspects of heart development.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 27-06-2018
DOI: 10.1007/S10735-018-9783-2
Abstract: In the original publication of the article, two errors were made in describing the equations for T
Publisher: Public Library of Science (PLoS)
Date: 11-06-2013
Publisher: The Company of Biologists
Date: 2019
DOI: 10.1242/DEV.181933
Abstract: During development, the p75 neurotrophin receptor (p75NTR) is widely expressed in the nervous system where it regulates neuronal differentiation, migration and axonal outgrowth. p75NTR also mediates the survival and death of newly born neurons, with functional outcomes being dependent on both timing and cellular context. Here we show that knockout of p75NTR from embryonic day 10 (E10) in neural progenitors using a conditional Nestin-Cre p75NTR floxed mouse causes increased apoptosis of progenitor cells. By E14.5, the number of Tbr2-positive progenitor cells was significantly reduced and the rate of neurogenesis was halved. Furthermore, in adult knockout mice, there were fewer cortical pyramidal neurons, interneurons, cholinergic basal forebrain neurons, and striatal neurons, corresponding to a relative reduction in volume of these structures. Thalamic midline fusion during early postnatal development was also impaired in Nestin-Cre p75NTR floxed mice, indicating a novel role of p75NTR in the formation of this structure. The phenotype of this strain demonstrates that p75NTR regulates multiple aspects of brain development, including cortical progenitor cell survival, and that expression during early neurogenesis is required for appropriate formation of telencephalic structures.
Publisher: Elsevier BV
Date: 2020
Publisher: Wiley
Date: 30-03-2023
DOI: 10.1002/JBM4.10739
Abstract: The nuclear factor I/X ( NFIX ) gene encodes a ubiquitously expressed transcription factor whose mutations lead to two allelic disorders characterized by developmental, skeletal, and neural abnormalities, namely, Malan syndrome (MAL) and Marshall–Smith syndrome (MSS). NFIX mutations associated with MAL mainly cluster in exon 2 and are cleared by nonsense‐mediated decay (NMD) leading to NFIX haploinsufficiency, whereas NFIX mutations associated with MSS are clustered in exons 6–10 and escape NMD and result in the production of dominant‐negative mutant NFIX proteins. Thus, different NFIX mutations have distinct consequences on NFIX expression. To elucidate the in vivo effects of MSS‐associated NFIX exon 7 mutations, we used CRISPR‐Cas9 to generate mouse models with exon 7 deletions that comprised: a frameshift deletion of two nucleotides ( Nfix Del2) in‐frame deletion of 24 nucleotides ( Nfix Del24) and deletion of 140 nucleotides ( Nfix Del140). Nfix +/Del2 , Nfix +/Del24 , Nfix +/Del140 , Nfix Del24/Del24 , and Nfix Del140/Del140 mice were viable, normal, and fertile, with no skeletal abnormalities, but Nfix Del2/Del2 mice had significantly reduced viability ( p 0.002) and died at 2–3 weeks of age. Nfix Del2 was not cleared by NMD, and Nfix Del2/Del2 mice, when compared to Nfix +/+ and Nfix +/Del2 mice, had: growth retardation short stature with kyphosis reduced skull length marked porosity of the vertebrae with decreased vertebral and femoral bone mineral content and reduced caudal vertebrae height and femur length. Plasma biochemistry analysis revealed Nfix Del2/Del2 mice to have increased total alkaline phosphatase activity but decreased C‐terminal telopeptide and procollagen‐type‐1‐N‐terminal propeptide concentrations compared to Nfix +/+ and Nfix +/Del2 mice. Nfix Del2/Del2 mice were also found to have enlarged cerebral cortices and ventricular areas but smaller dentate gyrus compared to Nfix +/+ mice. Thus, Nfix Del2/Del2 mice provide a model for studying the in vivo effects of NFIX mutants that escape NMD and result in developmental abnormalities of the skeletal and neural tissues that are associated with MSS. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
Publisher: MDPI AG
Date: 31-08-2022
Abstract: Background: Early diagnosis of metastatic epidural spinal cord compression (MESCC) is vital to expedite therapy and prevent paralysis. Staging CT is performed routinely in cancer patients and presents an opportunity for earlier diagnosis. Methods: This retrospective study included 123 CT scans from 101 patients who underwent spine MRI within 30 days, excluding 549 CT scans from 216 patients due to CT performed post-MRI, non-contrast CT, or a gap greater than 30 days between modalities. Reference standard MESCC gradings on CT were provided in consensus via two spine radiologists (11 and 7 years of experience) analyzing the MRI scans. CT scans were labeled using the original reports and by three radiologists (3, 13, and 14 years of experience) using dedicated CT windowing. Results: For normal/none versus low/high-grade MESCC per CT scan, all radiologists demonstrated almost perfect agreement with kappa values ranging from 0.866 (95% CI 0.787–0.945) to 0.947 (95% CI 0.899–0.995), compared to slight agreement for the reports (kappa = 0.095, 95%CI −0.098–0.287). Radiologists also showed high sensitivities ranging from 91.51 (95% CI 84.49–96.04) to 98.11 (95% CI 93.35–99.77), compared to 44.34 (95% CI 34.69–54.31) for the reports. Conclusion: Dedicated radiologist review for MESCC on CT showed high interobserver agreement and sensitivity compared to the current standard of care.
Publisher: Springer Science and Business Media LLC
Date: 07-01-2022
DOI: 10.1038/S41598-021-03976-4
Abstract: The generation of new neurons within the mammalian forebrain continues throughout life within two main neurogenic niches, the subgranular zone (SGZ) of the hippoc al dentate gyrus, and the subependymal zone (SEZ) lining the lateral ventricles. Though the SEZ is the largest neurogenic niche in the adult human forebrain, our understanding of the mechanisms regulating neurogenesis from development through aging within this region remains limited. This is especially pertinent given that neurogenesis declines dramatically over the postnatal lifespan. Here, we performed transcriptomic profiling on the SEZ from human post-mortem tissue from eight different life-stages ranging from neonates (average age ~ 2 months old) to aged adults (average age ~ 86 years old). We identified transcripts with concomitant profiles across these decades of life and focused on three of the most distinct profiles, namely (1) genes whose expression declined sharply after birth, (2) genes whose expression increased steadily with age, and (3) genes whose expression increased sharply in old age in the SEZ. Critically, these profiles identified neuroinflammation as becoming more prevalent with advancing age within the SEZ and occurring with time courses, one gradual (starting in mid-life) and one sharper (starting in old age).
Publisher: Springer Science and Business Media LLC
Date: 11-03-2016
DOI: 10.1007/S00586-016-4494-4
Abstract: To determine the effect of preoperative embolization on intraoperative blood loss in surgery for metastatic spinal tumours stratified by tumour type, type of surgical approach and extent of surgery. We retrospectively analysed 218 patients undergoing open surgery for metastatic spine tumours in our institution between 2005 and 2014. The cohort was ided to those who underwent preoperative embolization and those who did not. The patients were further stratified into different subgroups by tumour types, types of surgical procedure, levels of instrumentation and levels of decompression. Estimated blood loss, duration of surgery and length of hospital stay were compared between embolized and non-embolized cases in each subgroup. The impact of embolization extent, the time gap between embolization and index surgery on blood loss were also studied. Preoperative embolization was performed in 45 out of 218 patients. Non-embolized cases had insignificantly lesser blood loss and shorter duration of surgery compared to embolized cases in all subgroups. Embolization, however, conferred reduction in length of hospital stay in some of the subgroups, yet the differences were not significant. The patients who achieved total embolization bled less than those who achieved subtotal or partial embolization. The effectiveness of the embolization procedure in reducing intraoperative blood loss was found to be profound when the gap between embolization and surgery was within 24 h. Our study demonstrated that success of embolization in reducing blood loss depends on the extent of embolization and time interval between embolization and index surgery.
Publisher: Radiological Society of North America (RSNA)
Date: 07-2021
Publisher: American Physiological Society
Date: 08-2001
DOI: 10.1152/AJPCELL.2001.281.2.C486
Abstract: Drosophila slit is a secreted protein involved in midline patterning. Three vertebrate orthologs of the fly slit gene, Slit1, 2, and 3, have been isolated. Each displays overlapping, but distinct, patterns of expression in the developing vertebrate central nervous system, implying conservation of function. However, vertebrate Slit genes are also expressed in nonneuronal tissues where their cellular locations and functions are unknown. In this study, we characterized the cellular distribution and processing of mammalian Slit3 gene product, the least evolutionarily conserved of the vertebrate Slit genes, in kidney epithelial cells, using both cellular fractionation and immunolabeling. Slit3, but not Slit2, was predominantly localized within the mitochondria. This localization was confirmed using immunoelectron microscopy in cell lines and in mouse kidney proximal tubule cells. In confluent epithelial monolayers, Slit3 was also transported to the cell surface. However, we found no evidence of Slit3 proteolytic processing similar to that seen for Slit2. We demonstrated that Slit3 contains an NH 2 -terminal mitochondrial localization signal that can direct a reporter green fluorescent protein to the mitochondria. The equivalent region from Slit1 cannot elicit mitochondrial targeting. We conclude that Slit3 protein is targeted to and localized at two distinct sites within epithelial cells: the mitochondria, and then, in more confluent cells, the cell surface. Targeting to both locations is driven by specific NH 2 -terminal sequences. This is the first examination of Slit protein localization in nonneuronal cells, and this study implies that Slit3 has potentially unique functions not shared by other Slit proteins.
Publisher: Wiley
Date: 11-09-2014
DOI: 10.1002/DVDY.24182
Publisher: Springer Science and Business Media LLC
Date: 14-12-2020
Publisher: The Company of Biologists
Date: 03-2022
DOI: 10.1242/DEV.200076
Abstract: The hypothalamus displays staggering cellular ersity, chiefly established during embryogenesis by the interplay of several signalling pathways and a battery of transcription factors. However, the contribution of epigenetic cues to hypothalamus development remains unclear. We mutated the polycomb repressor complex 2 gene Eed in the developing mouse hypothalamus, which resulted in the loss of H3K27me3, a fundamental epigenetic repressor mark. This triggered ectopic expression of posteriorly expressed regulators (e.g. Hox homeotic genes), upregulation of cell cycle inhibitors and reduced proliferation. Surprisingly, despite these effects, single cell transcriptomic analysis revealed that most neuronal subtypes were still generated in Eed mutants. However, we observed an increase in glutamatergic/GABAergic double-positive cells, as well as loss/reduction of dopamine, hypocretin and Tac2-Pax6 neurons. These findings indicate that many aspects of the hypothalamic gene regulatory flow can proceed without the key H3K27me3 epigenetic repressor mark, but points to a unique sensitivity of particular neuronal subtypes to a disrupted epigenomic landscape.
Publisher: Springer Science and Business Media LLC
Date: 27-09-2007
Abstract: Blastomere injection of mRNA or antisense oligonucleotides has proven effective in analyzing early gene function in Xenopus . However, functional analysis of genes involved in neuronal differentiation and axon pathfinding by this method is often h ered by earlier function of these genes during development. Therefore, fine spatio-temporal control of over-expression or knock-down approaches is required to specifically address the role of a given gene in these processes. We describe here an electroporation procedure that can be used with high efficiency and low toxicity for targeting DNA and antisense morpholino oligonucleotides (MOs) into spatially restricted regions of the Xenopus CNS at a critical time-window of development (22–50 hour post-fertilization) when axonal tracts are first forming. The approach relies on the design of "electroporation chambers" that enable reproducible positioning of fixed-spaced electrodes coupled with accurate DNA/MO injection. Simple adjustments can be made to the electroporation chamber to suit the shape of different aged embryos and to alter the size and location of the targeted region. This procedure can be used to electroporate separate regions of the CNS in the same embryo allowing separate manipulation of growing axons and their intermediate and final targets in the brain. Our study demonstrates that electroporation can be used as a versatile tool to investigate molecular pathways involved in axon extension during Xenopus embryogenesis. Electroporation enables gain or loss of function studies to be performed with easy monitoring of electroporated cells. Double-targeted transfection provides a unique opportunity to monitor axon-target interaction in vivo . Finally, electroporated embryos represent a valuable source of MO-loaded or DNA transfected cells for in vitro analysis. The technique has broad applications as it can be tailored easily to other developing organ systems and to other organisms by making simple adjustments to the electroporation chamber.
Publisher: Springer Science and Business Media LLC
Date: 29-07-2014
DOI: 10.1245/S10434-014-3950-9
Abstract: Intraoperative cell salvage (IOCS) has not been widely adopted in oncological surgery due to the hypothetical concern of reinfusion of malignant cells. We evaluated the feasibility of IOCS in combination with leucocyte depletion filter (LDF) in metastatic spine tumour surgery (MSTS). Patients with known primary epithelial tumour, operated for metastatic spinal disease, were recruited. Blood s les were collected at five different stages during surgery: 2 stages from patient vein during induction and at the time of maximum tumour manipulation, 3 stages from the operative blood prior to IOCS processing, after IOCS processing, and after IOCS-LDF processing. Of the s les taken at each stage, 5 ml were analyzed for tumour cells using flow cytometry. Of 12 patients recruited, only 11 could be finally analyzed. Flow cytometry analysis of their s les showed that 8 of 11 patients had tumour cells in the unfiltered salvaged blood. In filtered salvaged blood, the tumour cell count was zero in the majority of s les (8/11 patients), whereas three patients' s les had a few tumour cells. The mean difference between the tumour cell quantity in the s les from the patient vein and filtered salvaged blood was significant. IOCS-LDF was shown to be effective in removing tumour cells from the blood salvaged during MSTS. If there were any tumour cells found, the quantity was significantly less than that in the patient's circulation. The results of this study reiterates the conclusions of our previous published work where we showed that IOCS-LDF treated blood in MSTS is safe for transfusion.
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.BIOPSYCH.2022.03.022
Abstract: Protein ubiquitination is a widespread, multifunctional, posttranslational protein modification, best known for its ability to direct protein degradation via the ubiquitin proteasome system (UPS). Ubiquitination is also reversible, and the human genome encodes over 90 deubiquitinating enzymes (DUBs), many of which appear to target specific subsets of ubiquitinated proteins. This review focuses on the roles of DUBs in neurodevelopmental disorders (NDDs). We present the current genetic evidence connecting 12 DUBs to a range of NDDs and the functional studies implicating at least 19 additional DUBs as candidate NDD genes. We highlight how the study of DUBs in NDDs offers critical insights into the role of protein degradation during brain development. Because one of the major known functions of a DUB is to antagonize the UPS, loss of function of DUB genes has been shown to culminate in loss of abundance of its protein substrates. The identification and study of NDD DUB substrates in the developing brain is revealing that they regulate networks of proteins that themselves are encoded by NDD genes. We describe the new technologies that are enabling the full resolution of DUB protein networks in the developing brain, with the view that this knowledge can direct the development of new therapeutic paradigms. The fact that the abundance of many NDD proteins is regulated by the UPS presents an exciting opportunity to combat NDDs caused by haploinsufficiency, because the loss of abundance of NDD proteins can be potentially rectified by antagonizing their UPS-based degradation.
Publisher: Wiley
Date: 22-11-2016
DOI: 10.1111/TRF.13912
Abstract: Despite advances in surgical techniques for spinal metastases, there is often substantial blood loss, resulting in patients requiring blood transfusion during the perioperative period. Allogeneic blood transfusion (ABT) has been the main replenishment method for lost blood. However, the impact of ABT on cancer‐related outcomes has been controversial in various studies. We aimed to evaluate the influence of perioperative ABT on disease progression and survival in patients undergoing metastatic spinal tumor surgery (MSTS). We conducted a retrospective study that included 247 patients who underwent MSTS at a single tertiary institution between 2005 and 2014. The impact of using perioperative ABT (either exposure to or quantities of transfusion) on disease progression and survival was assessed using Cox regression analyses while adjusting for potential confounding variables. Of 247 patients, 133 (54%) received ABT. The overall median number of blood units transfused was 2 (range, 0‐10 units). Neither blood transfusion exposure nor quantities of transfusion were associated with overall survival (hazard ratio [HR], 1.15 [p = 0.35] and 1.10 [p = 0.11], respectively) and progression‐free survival (HR, 0.87 [p = 0.18] and 0.98 [p = 0.11], respectively). The factors that influenced overall survival were primary tumor type and preoperative Eastern Cooperative Oncology Group performance status, whereas primary tumor type was the only factor that had an impact on progression‐free survival. This is the first study providing evidence that disease progression and survival in patients who undergo MSTS are less likely to be influenced by perioperative ABT. The worst oncologic outcomes are more likely to be caused by the clinical circumstances necessitating blood transfusion, but not transfusion itself. However, because ABT can have a propensity toward developing postoperative infections, including surgical site infection, the use of patient blood management interventions would be worthwhile rather than relying solely on ABTs for these patients, if and whenever possible.
Publisher: Springer Science and Business Media LLC
Date: 09-01-2005
DOI: 10.1038/NN1380
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2017
DOI: 10.1097/BSD.0000000000000400
Abstract: Prospective cohort study. Minimally invasive spinal surgery (MISS) has been gaining recognition in patients with metastatic spine disease (MSD). The advantages are reduction in blood loss, hospital stay, and postoperative morbidity. Most of the studies were case series with very few comparing the outcomes of MISS to open approaches. To evaluate and compare the clinical and perioperative outcomes of MISS versus open approach in patients with symptomatic MSD, who underwent posterior spinal stabilization and/or decompression. Our study included 45 MSD patients 27 managed by MISS and 18 by open approach. All patients had MSD presenting with symptoms of neurological deficit, spinal instability, or both. Preoperative, intraoperative, and postoperative data were collected for comparison of the 2 approaches. All patients were followed up until the end of study period (maximum up to 4 years from time of surgery) or till their demise. The clinical outcome measures were pain control, neurological and functional status, whereas perioperative outcomes were blood loss, operative time, length of hospital stay, and time taken to initiate radiotherapy/chemotherapy after index surgery. Majority of patients in both groups showed improvement in pain, neurological status, independent ambulation, and ECOG score in the postoperative period with no significant differences between the 2 groups. There was a significant reduction in intraoperative blood loss (621 mL less, P .001) in the MISS group. The average time to initiate radiotherapy after surgery was 13 days (range, 12–16 d) in MISS and 24 days (range, 16–40 d) in the open group. This difference was statistically significant ( P .001). Operative time and duration of hospital stay were also favorable in the MISS group, although the differences were not significant. MISS is comparable with open approach demonstrating similar improvements in clinical outcomes, that is pain control, neurological and functional status. MISS approaches have also shown promising results due to lesser intraoperative blood loss and allowing earlier radiotherapy/chemotherapy.
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.TMRV.2016.06.003
Abstract: Oncologic surgery is sometimes associated with substantial blood loss, and principles of patient blood management can be applied in the perioperative care of these patients. Although autologous salvaged blood is an option for perioperative blood conservation, it is often not used in oncologic surgery over concern of reinfusing tumor cells and thereby causing tumor dissemination. We reviewed the literature regarding safety and effectiveness of salvaged blood in oncologic surgery. Salvaged blood seems to be comparable to allogeneic blood in terms of safety. Because patients with primary or metastatic cancer are known to have circulating tumor cells in the absence of surgery, the concern of reinfusing malignant cells from the salvaged blood may be overstated. Reinfusion of salvaged blood has not been found to promote tumor dissemination or distant metastases. When used in patients with substantial blood loss, salvaged blood can be cost-effective. Intraoperative salvaged blood may be a useful adjunct to allogeneic blood resources.
Publisher: Springer Science and Business Media LLC
Date: 03-12-2018
DOI: 10.1007/S00429-018-1801-3
Abstract: Cerebellar granule neurons are the most numerous neuronal subtype in the central nervous system. Within the developing cerebellum, these neurons are derived from a population of progenitor cells found within the external granule layer of the cerebellar anlage, namely the cerebellar granule neuron precursors (GNPs). The timely proliferation and differentiation of these precursor cells, which, in rodents occurs predominantly in the postnatal period, is tightly controlled to ensure the normal morphogenesis of the cerebellum. Despite this, our understanding of the factors mediating how GNP differentiation is controlled remains limited. Here, we reveal that the transcription factor nuclear factor I X (NFIX) plays an important role in this process. Mice lacking Nfix exhibit reduced numbers of GNPs during early postnatal development, but elevated numbers of these cells at postnatal day 15. Moreover, Nfix
Publisher: Springer Science and Business Media LLC
Date: 25-10-2014
DOI: 10.1245/S10434-014-4178-4
Abstract: Posterior percutaneous spinal fixation (PPSF) has evolved to address the problems associated with metastatic spinal disease (MSD). This study was designed to evaluate the feasibility and spectrum of application of PPSF in the management of MSD, highlighting its clinical advantages. Twenty-seven consecutive patients with MSD treated with PPSF in our institution from January 2011 to June 2014 were studied. After a multidisciplinary assessment, all patients were considered for surgical intervention due to clinical presentation of either neural deficit, skeletal instability, or both. Some of these patients belonged to the poor prognostic category based on survival prognostic scoring systems. The patients were categorized into seven groups depending on the modality of PPSF used. Demographic data, operative details, and clinical outcomes were investigated for each category and compared pre- and postoperatively. The median age was 60 years (range 49-78 years). Generally, all patients either maintained or improved their neurological status and achieved pain alleviation. Ambulatory status and Eastern Cooperative Oncology Group (ECOG) scores were improved using any modality of PPSF. The pure-stabilization group had the lowest amount of mean blood loss, shortest operative time, and intensive care unit (ICU) and hospital stays, while the long-construct group was observed to have the greatest amount of blood loss, and longest operative time and ICU stay. For patients with MSD, even with predicted poor prognosis on survival prognostic scoring systems, it is possible to improve functional outcomes and quality of life with PPSF, keeping surgical morbidity to a minimum. PPSF allows patients with pure spinal instability to be addressed successfully with least morbidity.
Publisher: Oxford University Press (OUP)
Date: 10-2018
Abstract: Understanding the migration of newborn neurons within the brain presents a major challenge in contemporary biology. Neuronal migration is widespread within the developing brain but is also important within the adult brain. For instance, stem cells within the ventricular–subventricular zone (V-SVZ) and the subgranular zone of dentate gyrus of the adult rodent brain produce neuroblasts that migrate to the olfactory bulb and granule cell layer of the dentate gyrus, respectively, where they regulate key brain functions including innate olfactory responses, learning, and memory. Critically, our understanding of the factors mediating neuroblast migration remains limited. The transcription factor nuclear factor I X (NFIX) has previously been implicated in embryonic cortical development. Here, we employed conditional ablation of Nfix from the adult mouse brain and demonstrated that the removal of this gene from either neural stem and progenitor cells, or neuroblasts, within the V-SVZ culminated in neuroblast migration defects. Mechanistically, we identified aberrant neuroblast branching, due in part to increased expression of the guanylyl cyclase natriuretic peptide receptor 2 (Npr2), as a factor contributing to abnormal migration in Nfix-deficient adult mice. Collectively, these data provide new insights into how neuroblast migration is regulated at a transcriptional level within the adult brain.
Publisher: Springer Science and Business Media LLC
Date: 13-07-2021
DOI: 10.1186/S13104-021-05687-5
Abstract: Sulfation is an essential physiological process that regulates the function of a wide array of molecules involved in brain development. We have previously shown expression levels for the sulfate transporter Slc13a4 to be elevated during postnatal development, and that sulfate accumulation in the brains of Slc13a4 +/− mice is reduced, suggesting a role for this transporter during this critical window of brain development. In order to understand the pathways regulated by cellular sulfation within the brain, we performed a bulk RNA-sequencing analysis of the forebrain of postnatal day 20 (P20) Slc13a4 heterozygous mice and wild-type litter mate controls. We performed an RNA transcriptomic based sequencing screen on the whole forebrain from Slc13a4 +/− and Slc13a4 +/+ mice at P20. Differential expression analysis revealed 90 differentially regulated genes in the forebrain of Slc13a4 +/− mice (a p -value of 0.1 was considered as significant). Of these, 55 were upregulated, and 35 were downregulated in the forebrain of heterozygous mice. Moreover, when we stratified further with a ± 1.2 fold-change, we observed 38 upregulated, and 16 downregulated genes in the forebrain of heterozygous mice. This resource provides a useful tool to interrogate which pathways may require elevated sulfate levels to drive normal postnatal development of the brain.
Publisher: Radiological Society of North America (RSNA)
Date: 10-2022
Abstract: Background Lumbar spine MRI studies are widely used for back pain assessment. Interpretation involves grading lumbar spinal stenosis, which is repetitive and time consuming. Deep learning (DL) could provide faster and more consistent interpretation. Purpose To assess the speed and interobserver agreement of radiologists for reporting lumbar spinal stenosis with and without DL assistance. Materials and Methods In this retrospective study, a DL model designed to assist radiologists in the interpretation of spinal canal, lateral recess, and neural foraminal stenoses on lumbar spine MRI scans was used. Randomly selected lumbar spine MRI studies obtained in patients with back pain who were 18 years and older over a 3-year period, from September 2015 to September 2018, were included in an internal test data set. Studies with instrumentation and scoliosis were excluded. Eight radiologists, each with 2-13 years of experience in spine MRI interpretation, reviewed studies with and without DL model assistance with a 1-month washout period. Time to diagnosis (in seconds) and interobserver agreement (using Gwet κ) were assessed for stenosis grading for each radiologist with and without the DL model and compared with test data set labels provided by an external musculoskeletal radiologist (with 32 years of experience) as the reference standard. Results Overall, 444 images in 25 patients (mean age, 51 years ± 20 [SD] 14 women) were evaluated in a test data set. DL-assisted radiologists had a reduced interpretation time per spine MRI study, from a mean of 124-274 seconds (SD, 25-88 seconds) to 47-71 seconds (SD, 24-29 seconds) (
Publisher: The Company of Biologists
Date: 15-06-2021
DOI: 10.1242/DEV.196675
Abstract: The balance between stem cell potency and lineage specification entails the integration of both extrinsic and intrinsic cues, which ultimately influence gene expression through the activity of transcription factors. One ex le of this is provided by the Hippo signalling pathway, which plays a central role in regulating organ size during development. Hippo pathway activity is mediated by the transcriptional co-factors Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ), which interact with TEA domain (TEAD) proteins to regulate gene expression. Although the roles of YAP and TAZ have been intensively studied, the roles played by TEAD proteins are less well understood. Recent studies have begun to address this, revealing that TEADs regulate the balance between progenitor self-renewal and differentiation throughout various stages of development. Furthermore, it is becoming apparent that TEAD proteins interact with other co-factors that influence stem cell biology. This Primer provides an overview of the role of TEAD proteins during development, focusing on their role in Hippo signalling as well as within other developmental, homeostatic and disease contexts.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2016
Publisher: Oxford University Press (OUP)
Date: 08-04-2009
Publisher: Wiley
Date: 16-09-2017
DOI: 10.1111/TRF.14311
Abstract: The question of independent association between allogeneic blood transfusion (ABT) and postoperative complications in cancer surgeries has been controversial and remains so. In metastatic spine tumor surgery (MSTS), previous studies investigated the influence of ABT on survival, but not on postoperative complications. We aimed to evaluate the influence of perioperative ABT on postoperative complications and infections in patients undergoing MSTS. This retrospective study included 247 patients who underwent MSTS at a single tertiary institution between 2005 and 2014. The outcome measures were postoperative complications and infections within 30 days after MSTS. Multivariate logistic regression analyses were performed to assess influence of blood transfusion on the outcomes after adjusting for potential confounders. Of 247 patients, 133 (54%) received ABT with overall median (range) of 2 (0-10) units. The adjusted odds of developing any postoperative complication was 2.27 times higher in patients with transfusion (95% confidence interval [CI], 1.17-4.38 p = 0.01) and 1.24 times higher odds per every unit increase in blood transfusion (95% CI, 1.05-1.46 p < 0.01). Exposure to blood transfusion also increased the odds of having overall postoperative infections (odds ratio, 3.58 95% CI, 1.15-11.11 p = 0.02) and there were 1.24 times higher odds per every unit increase in transfusion (95% CI, 1.01-1.54 p = 0.04). This study adds evidence to the literature implicating ABT to be influential on postoperative complications and infections in patients undergoing MSTS. Appropriate blood management measures should, therefore, be given a crucial place in the care of these patients so as to reduce any putative effect of blood transfusion.
Publisher: Elsevier BV
Date: 07-2021
DOI: 10.1016/J.YGENO.2021.04.026
Abstract: Chromatin immunoprecipitation followed by sequencing (ChIP-seq) is the primary protocol for detecting genome-wide DNA-protein interactions, and therefore a key tool for understanding transcriptional regulation. A number of factors, including low specificity of antibody and cellular heterogeneity of s le, may cause "peak" callers to output noise and experimental artefacts. Statistically combining multiple experimental replicates from the same condition could significantly enhance our ability to distinguish actual transcription factor binding events, even when peak caller accuracy and consistency of detection are compromised. We adapted the rank-product test to statistically evaluate the reproducibility from any number of ChIP-seq experimental replicates. We demonstrate over a number of benchmarks that our adaptation "ChIP-R" (pronounced 'chipper') performs as well as or better than comparable approaches on recovering transcription factor binding sites in ChIP-seq peak data. We also show ChIP-R extends to evaluate ATAC-seq peaks, finding reproducible peak sets even at low sequencing depth. ChIP-R decomposes peaks across replicates into "fragments" which either form part of a peak in a replicate, or not. We show that by re-analysing existing data sets, ChIP-R reconstructs reproducible peaks from fragments with enhanced biological enrichment relative to current strategies.
Publisher: The Company of Biologists
Date: 02-2018
DOI: 10.1242/DEV.155689
Abstract: Our understanding of the transcriptional programme underpinning adult hippoc al neurogenesis is incomplete. In mice, under basal conditions, adult hippoc al neural stem cells (AH-NSCs) generate neurons and astrocytes, but not oligodendrocytes. The factors limiting oligodendrocyte production, however, remain unclear. Here, we reveal that the transcription factor NFIX plays a key role in this process. NFIX is expressed by AH-NSCs, and its expression is sharply upregulated in adult hippoc al neuroblasts. Conditional ablation of Nfix from AH-NSCs, coupled with lineage tracing, transcriptomic sequencing and behavioural studies collectively reveal that NFIX is cell-autonomously required for neuroblast maturation and survival. Moreover, a small number of AH-NSCs also develop into oligodendrocytes following Nfix deletion. Remarkably, when Nfix is deleted specifically from intermediate progenitor cells and neuroblasts using a Dcx-creERT2 driver, these cells also display elevated signatures of oligodendrocyte gene expression. Together, these results demonstrate the central role played by NFIX in neuroblasts within the adult hippoc al stem cell neurogenic niche in promoting the maturation and survival of these cells, while concomitantly repressing oligodendrocyte gene expression signatures.
Publisher: Springer Science and Business Media LLC
Date: 27-01-2016
DOI: 10.1245/S10434-016-5092-8
Abstract: Metastatic spine tumor surgery (MSTS) can be associated with significant blood loss. Previous studies did not provide comprehensive data on blood loss in MSTS. Thorough study elaborating the blood loss, transfusion requirement, and their influencing factors is required. This study aimed to investigate the estimated blood loss and transfusion requirements associated with various surgical approaches and surgically managed vertebral levels for spinal metastases from different primary tumors. The study retrospectively evaluated 243 patients who underwent surgery for metastatic spine tumors at the authors' institution between 2005 and 2014. Estimated intraoperative blood loss and transfusion requirement were assessed for different primary tumors including lung, breast, prostate, gastrointestinal, renal, liver, thyroid, myeloma/lymphoma, and others types of surgical procedure (cervical corpectomy ± stabilization, thoracolumbar posterior decompression ± instrumentation, thoracolumbar corpectomy, minimally invasive surgery) and levels of instrumentation and decompression. Multivariate linear regression was attempted to investigate the factors influencing blood loss and transfusion requirements. The mean blood loss was 870 ± 720 ml, and the average blood transfusion was 1.5 ± 1.9 U. The mean blood loss was 1103 ml for patients who received blood transfusion and 597 ml for those who did not. Multivariate analysis showed that the significant factors influencing blood loss were primary tumor, type of surgery, and prolonged operative time. The influencing factors for blood transfusion were primary tumor, type of surgery, preoperative hemoglobin, and prolonged operative time. Significant variations in blood loss and transfusion requirement were based on primary tumor of spinal metastases, surgical approaches, and operative time. These findings will help clinicians in preoperative planning to address the problem of blood loss during MSTS.
Publisher: Wiley
Date: 23-08-2017
DOI: 10.1111/TME.12453
Abstract: The use of salvaged blood in oncological surgery has been a matter of controversy over the years. This is due to the concern of systemic dissemination of reinfused tumour cells. Recent literature, across disciplines, has shed considerable light on its safety in terms of tumour recurrence, progression and overall survival rates. This clinical safety demonstrates the apparent metastatic inefficiency of reinfused tumour cells. The proof of this concept comes from various studies that have shown that salvaged blood has no tumour cells, or has a significantly lower count as compared to the patient's original circulatory tumour load. Recently, we took a step further and found that the tumour cells in the salvaged blood lose the capacity to replicate. In this review, we revisited the safety of salvaged blood from the point of view of metastatic potential. We have presented basic and applied science evidence regarding the innocuous nature of tumour cells that have been subjected to the cell salvage process. The understanding of the metastatic efficiency or the lack of it in tumour cells subjected to salvage process is key to allay the concerns conventionally associated with the use of salvaged blood in tumour surgery. Based on the available literature, we surmise that the prevalent apprehensions on the usage of salvaged blood are ill-founded and further substantiate why tumour cells in the salvaged blood could be regarded as cells with non-metastatic potential.
Publisher: Springer Science and Business Media LLC
Date: 14-02-2018
DOI: 10.1007/S10735-018-9761-8
Abstract: Measuring the mean duration of synthesis-phase (T
Publisher: The Company of Biologists
Date: 11-2015
DOI: 10.1242/DEV.119909
Abstract: Transcription factors act during cortical development as master regulatory genes that specify cortical arealization and cellular identities. Although numerous transcription factors have been identified as being crucial for cortical development, little is known about their downstream targets and how they mediate the emergence of specific neuronal connections via selective axon guidance. The EMX transcription factors are essential for early patterning of the cerebral cortex, but whether EMX1 mediates interhemispheric connectivity by controlling corpus callosum formation remains unclear. Here, we demonstrate that in mice on the C57Bl/6 background EMX1 plays an essential role in the midline crossing of an axonal subpopulation of the corpus callosum derived from the anterior cingulate cortex. In the absence of EMX1, cingulate axons display reduced expression of the axon guidance receptor NRP1 and form aberrant axonal bundles within the rostral corpus callosum. EMX1 also functions as a transcriptional activator of Nrp1 expression in vitro, and overexpression of this protein in Emx1 knockout mice rescues the midline-crossing phenotype. These findings reveal a novel role for the EMX1 transcription factor in establishing cortical connectivity by regulating the interhemispheric wiring of a subpopulation of neurons within the mouse anterior cingulate cortex.
Publisher: Hindawi Limited
Date: 2016
DOI: 10.1155/2016/9745315
Abstract: The cerebral cortex is essential for our higher cognitive functions and emotional reasoning. Arguably, this brain structure is the distinguishing feature of our species, and yet our remarkable cognitive capacity has seemingly come at a cost to the regenerative capacity of the human brain. Indeed, the capacity for regeneration and neurogenesis of the brains of vertebrates has declined over the course of evolution, from fish to rodents to primates. Nevertheless, recent evidence supporting the existence of neural stem cells (NSCs) in the adult human brain raises new questions about the biological significance of adult neurogenesis in relation to ageing and the possibility that such endogenous sources of NSCs might provide therapeutic options for the treatment of brain injury and disease. Here, we highlight recent insights and perspectives on NSCs within both the developing and adult cerebral cortex. Our review of NSCs during development focuses upon the ersity and therapeutic potential of these cells for use in cellular transplantation and in the modeling of neurodevelopmental disorders. Finally, we describe the cellular and molecular characteristics of NSCs within the adult brain and strategies to harness the therapeutic potential of these cell populations in the treatment of brain injury and disease.
Publisher: Elsevier BV
Date: 04-2021
Publisher: Society for Neuroscience
Date: 02-01-2008
DOI: 10.1523/JNEUROSCI.4490-07.2008
Abstract: NF-protocadherin (NFPC)-mediated cell–cell adhesion plays a critical role in vertebrate neural tube formation. NFPC is also expressed during the period of axon tract formation, but little is known about its function in axonogenesis. Here we have tested the role of NFPC and its cytosolic cofactor template-activating factor 1 (TAF1) in the emergence of the Xenopus retinotectal projection. NFPC is expressed in the developing retina and optic pathway and is abundant in growing retinal axons. Inhibition of NFPC function in developing retinal ganglion cells (RGCs) severely reduces axon initiation and elongation and suppresses dendrite genesis. Furthermore, an identical phenotype occurs when TAF1 function is blocked. These data provide evidence that NFPC regulates axon initiation and elongation and indicate a conserved role for TAF1, a transcriptional regulator, as a downstream cytosolic effector of NFPC in RGCs.
Publisher: MDPI AG
Date: 02-08-2022
Abstract: Nuclear factor one X (NFIX) is a transcription factor required for normal ependymal development. Constitutive loss of Nfix in mice (Nfix−/−) is associated with hydrocephalus and sloughing of the dorsal ependyma within the lateral ventricles. Previous studies have implicated NFIX in the transcriptional regulation of genes encoding for factors essential to ependymal development. However, the cellular and molecular mechanisms underpinning hydrocephalus in Nfix−/− mice are unknown. To investigate the role of NFIX in hydrocephalus, we examined ependymal cells in brains from postnatal Nfix−/− and control (Nfix+/+) mice using a combination of confocal and electron microscopy. This revealed that the ependymal cells in Nfix−/− mice exhibited abnormal cilia structure and disrupted localisation of adhesion proteins. Furthermore, we modelled ependymal cell adhesion using epithelial cell culture and revealed changes in extracellular matrix and adherens junction gene expression following knockdown of NFIX. Finally, the ablation of Nfix from ependymal cells in the adult brain using a conditional approach culminated in enlarged ventricles, sloughing of ependymal cells from the lateral ventricles and abnormal localisation of adhesion proteins, which are phenotypes observed during development. Collectively, these data demonstrate a pivotal role for NFIX in the regulation of cell adhesion within ependymal cells of the lateral ventricles.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.TCB.2018.09.003
Abstract: The past decade has seen incredible advances in the field of stem cell biology that have greatly improved our understanding of development and provided important insights into pathological processes. Transcription factors (TFs) play a central role in mediating stem cell proliferation, quiescence, and differentiation. One TF that contributes to these processes is Nuclear Factor One X (NFIX). Recently, NFIX activity has been shown to be essential in multiple organ systems and to have important translational impacts for human health. Here, we describe recent studies showing the contribution of NFIX to muscle development and muscular dystrophies, hematopoiesis, cancer, and neural stem cell biology, highlighting the importance of this knowledge in the development of therapeutic targets.
Publisher: Wiley
Date: 10-08-2012
DOI: 10.1002/CNE.23081
Abstract: The nuclear factor one (NFI) family of transcription factors consists of four members in vertebrates, NFIA, NFIB, NFIC, and NFIX, which share a highly conserved N-terminal DNA-binding domain. NFI genes are widely expressed in the developing mouse brain, and mouse mutants lacking NFIA, NFIB, or NFIX exhibit developmental deficits in several areas, including the cortex, hippoc us, pons, and cerebellum. Here we analyzed the expression of NFIA and NFIB in the developing and adult olfactory bulb (OB), rostral migratory stream (RMS), and subventricular zone (SVZ). We found that NFIA and NFIB are expressed within these regions during embryonic and postnatal development and in the adult. Immunohistochemical analysis using cell-type-specific markers revealed that migrating neuroblasts in the adult brain express NFI transcription factors, as do astrocytes within the RMS and progenitor cells within the SVZ. Moreover, astrocytes within the OB express NFIA, whereas mitral cells within the OB express NFIB. Taken together these data show that NFIA and NFIB are expressed in both the developing and the adult OB and in the RMS and SVZ, indicative of a regulatory role for these transcription factors in the development of this facet of the olfactory system.
Publisher: The Company of Biologists
Date: 2020
DOI: 10.1242/BIO.053132
Abstract: Sulfate is a key anion that is required for a range of physiological functions within the brain. These include sulfonation of extracellular proteoglycans to facilitate local growth factor binding and to regulate the shape of morphogen gradients during development. We have previously shown that mice lacking one allele of the sulfate transporter Slc13a4 exhibit reduced sulfate transport into the brain, deficits in social behaviour, reduced performance in learning and memory tasks, and abnormal neurogenesis within the ventricular/subventricular zone lining the lateral ventricles. However, whether these mice have deficits in hippoc al neurogenesis was not addressed. Here, we demonstrate that adult Slc13a4+/- mice have increased neurogenesis within the subgranular zone (SGZ) of the hippoc al dentate gyrus, with elevated numbers of neural progenitor cells and intermediate progenitors. In contrast, by 12 months of age there were reduced numbers of neural stem cells in the SGZ of heterozygous mice. Importantly, we did not observe any changes in proliferation when we isolated and cultured progenitors in vitro in neurosphere assays, suggestive of a cell-extrinsic requirement for sulfate in regulating hippoc al neurogenesis. Collectively, these data demonstrate a requirement for sulfate transport during postnatal brain development to ensure normal adult hippoc al neurogenesis.
Publisher: Cold Spring Harbor Laboratory
Date: 25-11-2020
DOI: 10.1101/2020.11.24.396960
Abstract: Chromatin immunoprecipitation followed by sequencing (ChIP-seq) is the primary protocol for detecting genome-wide DNA-protein interactions, and therefore a key tool for understanding transcriptional regulation. A number of factors, including low specificity of antibody and cellular heterogeneity of s le, may cause “peak” callers to output noise and experimental artefacts. Statistically combining multiple experimental replicates from the same condition could significantly enhance our ability to distinguish actual transcription factor binding events, even when peak caller accuracy and consistency of detection are compromised. We adapted the rank-product test to statistically evaluate the reproducibility from any number of ChIP-seq experimental replicates. We demonstrate over a number of benchmarks that our adaptation “ChIP-R” (pronounced ‘chipper’) performs as well as or better than comparable approaches on recovering transcription factor binding sites in ChIP-seq peak data. We also show ChIP-R extends to evaluate ATAC-seq peaks, finding reproducible peak sets even at low sequencing depth. ChIP-R decomposes peaks across replicates into “fragments” which either form part of a peak in a replicate, or not. We show that by re-analysing existing data sets, ChIP-R reconstructs reproducible peaks from fragments with enhanced biological enrichment relative to current strategies.
Publisher: Springer Science and Business Media LLC
Date: 16-02-2018
Publisher: Wiley
Date: 2008
DOI: 10.1002/CNE.21645
Abstract: Three members of the Nuclear Factor I (Nfi) gene family of transcription factors Nfia, Nfib, and Nfix are highly expressed in the developing mouse brain. Nfia and Nfib knockout mice display profound defects in the development of midline glial populations and the development of forebrain commissures (das Neves et al. [1999] Proc Natl Acad Sci U S A 96:11946-11951 Shu et al. [2003] J Neurosci 23:203-212 Steele-Perkins et al. [2005] Mol Cell Biol 25:685-698). These findings suggest that Nfi genes may regulate the substrate over which the commissural axons grow to reach targets in the contralateral hemisphere. However, these genes are also expressed in the cerebral cortex and, thus, it is important to assess whether this expression correlates with a cell-autonomous role in cortical development. Here we detail the protein expression of NFIA and NFIB during embryonic and postnatal mouse forebrain development. We find that both NFIA and NFIB are expressed in the deep cortical layers and subplate prenatally and display dynamic expression patterns postnatally. Both genes are also highly expressed in the developing hippoc us and in the diencephalon. We also find that principally neither NFIA nor NFIB are expressed in callosally projecting neurons postnatally, emphasizing the role for midline glial cell populations in commissure formation. However, a large proportion of laterally projecting neurons express both NFIA and NFIB, indicating a possible cell-autonomous role for these transcription factors in corticospinal neuron development. Collectively, these data suggest that, in addition to regulating the formation of axon guidance substrates, these genes also have cell-autonomous roles in cortical development.
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.JID.2020.12.039
Abstract: Phenotypic plasticity drives cancer progression, impacts treatment response, and is a major driver of therapeutic resistance. In melanoma, a regulatory axis between the MITF and BRN2 transcription factors has been reported to promote tumor heterogeneity by mediating switching between proliferative and invasive phenotypes, respectively. Despite strong evidence that subpopulations of cells that exhibit a BRN2
Publisher: Springer Science and Business Media LLC
Date: 11-05-2021
DOI: 10.1038/S41467-021-22888-5
Abstract: Intellectual disability (ID) and autism spectrum disorder (ASD) are the most common neurodevelopmental disorders and are characterized by substantial impairment in intellectual and adaptive functioning, with their genetic and molecular basis remaining largely unknown. Here, we identify biallelic variants in the gene encoding one of the Elongator complex subunits, ELP2, in patients with ID and ASD. Modelling the variants in mice recapitulates the patient features, with brain imaging and tractography analysis revealing microcephaly, loss of white matter tract integrity and an aberrant functional connectome. We show that the Elp2 mutations negatively impact the activity of the complex and its function in translation via tRNA modification. Further, we elucidate that the mutations perturb protein homeostasis leading to impaired neurogenesis, myelin loss and neurodegeneration. Collectively, our data demonstrate an unexpected role for tRNA modification in the pathogenesis of monogenic ID and ASD and define Elp2 as a key regulator of brain development.
Publisher: Springer Science and Business Media LLC
Date: 06-08-2018
Publisher: Frontiers Media SA
Date: 13-04-2021
Publisher: Elsevier BV
Date: 2006
Publisher: Wiley
Date: 14-01-2020
DOI: 10.1111/GBB.12637
Abstract: Sotos syndrome is a developmental disorder characterized by a suite of clinical features. In children, the three cardinal features of Sotos syndrome are a characteristic facial appearance, learning disability and overgrowth (height and/or head circumference > 2 SDs above average). These features are also evident in adults with this syndrome. Over 90% of Sotos syndrome patients are haploinsufficient for the gene encoding nuclear receptor-binding Su(var)3-9, Enhancer-of-zesteand Trithorax domain-containing protein 1 (NSD1). NSD1 is a histone methyltransferase that catalyzes the methylation of lysine residue 36 on histone H3. However, although the symptomology of Sotos syndrome is well established, many aspects of NSD1 biology remain unknown. Here, we assessed the expression of Nsd1 within the mouse brain, and showed a predominantly neuronal pattern of expression for this histone-modifying factor. We also generated a mouse strain lacking one allele of Nsd1 and analyzed morphological and behavioral characteristics in these mice, showing behavioral characteristics reminiscent of some of the deficits seen in Sotos syndrome patients.
Publisher: Public Library of Science (PLoS)
Date: 28-10-2021
DOI: 10.1371/JOURNAL.PGEN.1009334
Abstract: Homozygous nonsense mutations in CEP55 are associated with several congenital malformations that lead to perinatal lethality suggesting that it plays a critical role in regulation of embryonic development. CEP55 has previously been studied as a crucial regulator of cytokinesis, predominantly in transformed cells, and its dysregulation is linked to carcinogenesis. However, its molecular functions during embryonic development in mammals require further investigation. We have generated a Cep55 knockout ( Cep55 -/- ) mouse model which demonstrated preweaning lethality associated with a wide range of neural defects. Focusing our analysis on the neocortex, we show that Cep55 -/- embryos exhibited depleted neural stem rogenitor cells in the ventricular zone as a result of significantly increased cellular apoptosis. Mechanistically, we demonstrated that Cep55-loss downregulates the pGsk3β/β-Catenin/Myc axis in an Akt-dependent manner. The elevated apoptosis of neural stem rogenitors was recapitulated using Cep55-deficient human cerebral organoids and we could rescue the phenotype by inhibiting active Gsk3β. Additionally, we show that Cep55-loss leads to a significant reduction of ciliated cells, highlighting a novel role in regulating ciliogenesis. Collectively, our findings demonstrate a critical role of Cep55 during brain development and provide mechanistic insights that may have important implications for genetic syndromes associated with Cep55-loss.
Publisher: Mary Ann Liebert Inc
Date: 15-09-2015
Abstract: Murine postnatal neural stem cells (NSCs) give rise to neurons, astrocytes, or oligodendrocytes (OLs) however, our knowledge of the genes that control this lineage specification is incomplete. In this study, we show that nuclear factor I X (NFIX), a transcription factor known to regulate NSC quiescence, also suppresses oligodendrogenesis (ODG) from NSCs. Immunostaining reveals little or no expression of NFIX in OL lineage cells both in vivo and in vitro. Loss of NFIX from subventricular zone (SVZ) NSCs results in enhanced ODG both in vivo and in vitro, while forced expression of NFIX blocks NSC differentiation into OLs in vitro. RNA-seq analysis shows that genes previously shown to be differentially expressed in OL progenitors are significantly enriched in RNA from Nfix(-/-) versus wild-type NSCs. These data indicate that NFIX influences the lineage specification of postnatal SVZ NSCs, specifically suppressing ODG.
Publisher: Wiley
Date: 20-12-2002
DOI: 10.1002/BIES.10199
Abstract: First isolated in the fly and now characterised in vertebrates, the Slit proteins have emerged as pivotal components controlling the guidance of axonal growth cones and the directional migration of neuronal precursors. As well as extensive expression during development of the central nervous system (CNS), the Slit proteins exhibit a striking array of expression sites in non-neuronal tissues, including the urogenital system, limb primordia and developing eye. Zebrafish Slit has been shown to mediate mesodermal migration during gastrulation, while Drosophila slit guides the migration of mesodermal cells during myogenesis. This suggests that the actions of these secreted molecules are not simply confined to the sphere of CNS development, but rather act in a more general fashion during development and throughout the lifetime of an organism. This review focuses on the non-neuronal activities of Slit proteins, highlighting a common role for the Slit family in cellular migration.
Publisher: Elsevier BV
Date: 02-2017
Publisher: Springer Science and Business Media LLC
Date: 30-10-2019
DOI: 10.1007/S10735-019-09850-Y
Abstract: Microscopy is advancing at a rapid pace, enabling high-speed, high-resolution analyses to be conducted in a wide range of cellular contexts. For ex le, the capacity to quickly capture high-resolution images from multiple optical sections over multiple channels with confocal microscopy has allowed researchers to gain deeper understanding of tissue morphology via techniques such as three-dimensional rendering, as have more recent advances such as lattice light sheet microscopy and superresolution structured illumination microscopy. With this, though, comes the challenge of storing, curating, analysing and sharing data. While there are ways in which this has been attempted previously, few approaches have provided a central repository in which all of these different aspects of microscopy can be seamlessly integrated. Here, we describe a web-based storage and analysis platform called Microndata, that enables relatively straightforward storage, annotation, tracking, analysis and multi-user access to micrographs. This easy to use tool will simplify and harmonise laboratory work flows, and, importantly, will provide a central storage repository that is readily accessed, even after the researcher responsible for capturing the images has left the laboratory. Microndata is open-source software, available at
Publisher: Informa UK Limited
Date: 2016
Publisher: Cold Spring Harbor Laboratory
Date: 15-08-2013
Abstract: The majority of neural stem cells (NSCs) in the adult brain are quiescent, and this fraction increases with aging. Although signaling pathways that promote NSC quiescence have been identified, the transcriptional mechanisms involved are mostly unknown, largely due to lack of a cell culture model. In this study, we first demonstrate that NSC cultures (NS cells) exposed to BMP4 acquire cellular and transcriptional characteristics of quiescent cells. We then use epigenomic profiling to identify enhancers associated with the quiescent NS cell state. Motif enrichment analysis of these enhancers predicts a major role for the nuclear factor one (NFI) family in the gene regulatory network controlling NS cell quiescence. Interestingly, we found that the family member NFIX is robustly induced when NS cells enter quiescence. Using genome-wide location analysis and overexpression and silencing experiments, we demonstrate that NFIX has a major role in the induction of quiescence in cultured NSCs. Transcript profiling of NS cells overexpressing or silenced for Nfix and the phenotypic analysis of the hippoc us of Nfix mutant mice suggest that NFIX controls the quiescent state by regulating the interactions of NSCs with their microenvironment.
Publisher: SAGE Publications
Date: 03-10-2017
Publisher: Public Library of Science (PLoS)
Date: 21-10-2015
Publisher: Springer Science and Business Media LLC
Date: 05-12-2008
DOI: 10.1007/S12035-008-8048-6
Abstract: Transcription factors are key regulators of central nervous system (CNS) development and brain function. Research in this area has now uncovered a new key player-the nuclear factor one (NFI) gene family. It has been almost a decade since the phenotype of the null mouse mutant for the nuclear factor one A transcription factor was reported. Nfia null mice display a striking brain phenotype including agenesis of the corpus callosum and malformation of midline glial populations needed to guide axons of the corpus callosum across the midline of the developing brain. Besides NFIA, there are three other NFI family members in vertebrates: NFIB, NFIC, and NFIX. Since generation of the Nfia knockout (KO) mice, KO mice for all other family members have been generated, and defects in one or more organ systems have been identified for all four NFI family members (collectively referred to as NFI here). Like the Nfia KO mice, the Nfib and Nfix KO mice also display a brain phenotype, with the Nfib KO forebrain phenotype being remarkably similar to that of Nfia. Over the past few years, studies have highlighted NFI as a key payer in a variety of CNS processes including axonal outgrowth and guidance and glial and neuronal cell differentiation. Here, we discuss the importance and role of NFI in these processes in the context of several CNS systems including the neocortex, hippoc us, cerebellum, and spinal cord at both cellular and molecular levels.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2018
DOI: 10.1097/BSD.0000000000000475
Abstract: Retrospective analysis. Recent advancements in systemic treatment of lung cancer have significantly improved the survival of patients with certain histolopathologic and molecular subtypes. Existing prognostic scores do not account for this and patients with lung cancer spinal metastases are grouped together as poor prognostic candidates, and consequently, some may be inappropriately denied palliative spine surgery. The objective of the study was to study whether the expected survival in patients with lung cancer spinal metastases is affected by histolopathologic and molecular subtypes in the context of modern systemic therapy. We retrospectively reviewed all patients with histologically confirmed lung cancer treated for spinal metastases at our institution between 2001 and 2012. Patients’ demographics, histopathologic details, treatment modalities, and survival data were collected. The primary outcome was survival from time of spinal metastases diagnosis. The Cox regression analysis was used to evaluate the influence of tumor histology, molecular profile and treatment modality on survival. The Kaplan-Meier survival analysis was conducted to compare lung cancer subtypes, as well as various treatment regimens. Out of 180 patients, 51 underwent surgery for spinal metastases. Female sex ( P =0.019), absence of palsy ( P =0.023), good Karnofsky performance scores ( P .001), and non–small cell lung cancer (NSCLC) ( P =0.002) were favorable prognostic factors. Patients who received systemic therapy, including tyrosine kinase inhibitors, platinum doublet chemotherapy, or both showed increased survival ( P .01). The median survival time was 2.40 months [95% confidence interval (CI), 2.13–2.68] in the small cell lung cancer cohort, with no patients surviving past a year 5.10 months (95% CI, 3.78–6.41) in the NSCLC cohort, with 25.9% 1-year survival and 13.3 months (95% CI, 2.26–24.40) in adenocarcinoma patients who received both tyrosine kinase inhibitors and platinum doublet therapy, with 50.0% 1-year survival. NSCLC, systemic therapy, female sex, absence of palsy and good Karnofsky performance scores are all independent favorable prognostic factors for patients with lung cancer spinal metastases. These should be routinely considered during prognostication.
Publisher: Elsevier BV
Date: 2014
Publisher: Wiley
Date: 07-08-2020
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 01-2016
End Date: 01-2019
Amount: $379,400.00
Funder: Australian Research Council
View Funded ActivityStart Date: 03-2013
End Date: 02-2017
Amount: $684,422.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2023
End Date: 01-2026
Amount: $532,915.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2018
End Date: 12-2021
Amount: $419,122.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2022
End Date: 01-2025
Amount: $553,796.00
Funder: Australian Research Council
View Funded Activity