ORCID Profile
0000-0002-4545-8811
Current Organisation
Macquarie University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Biochemistry and Cell Biology | Nanobiotechnology | Cell Neurochemistry
Expanding Knowledge in the Biological Sciences | Expanding Knowledge in the Medical and Health Sciences |
Publisher: Elsevier BV
Date: 11-2015
Publisher: IOP Publishing
Date: 08-07-2019
Abstract: Fluorescent nanodiamonds (FNDs) are extremely photostable markers and nanoscale sensors, which are increasingly used in biomedical applications. Nanoparticle size is a critical parameter in the majority of these applications. Yet, the effect of particle size on FND's fluorescence and colloidal properties is not well understood today. Here, we investigate the fluorescence and colloidal stability of commercially available high-pressure high-temperature FNDs containing nitrogen-vacancy (NV) centers in biological media. Unconjugated FNDs in sizes ranging between 10 nm and 140 nm with an oxidized surface are studied using dynamic light scattering and fluorescence spectroscopy. We determine their colloidal stability in water, fetal bovine serum, Dulbecco's Modified Eagle Medium and complete media. The FNDs' relative fluorescence brightness, the NV charge-state, and the FND fluorescence against media autofluorescence are analyzed as a function of FND size. Our results will enable researchers in biology and beyond to identify the most promising FND particle size for their application.
Publisher: Springer Science and Business Media LLC
Date: 14-03-2018
DOI: 10.1038/S41598-018-22702-1
Abstract: Bio-imaging is a key technique in tracking and monitoring important biological processes and fundamental biomolecular interactions, however the interference of background autofluorescence with targeted fluorophores is problematic for many bio-imaging applications. This study reports on two novel methods for reducing interference with cellular autofluorescence for bio-imaging. The first method uses fluorescent nanodiamonds (FNDs), containing nitrogen vacancy centers. FNDs emit at near-infrared wavelengths typically higher than most cellular autofluorescence and when appropriately functionalized, can be used for background-free imaging of targeted biomolecules. The second method uses europium-chelating tags with long fluorescence lifetimes. These europium-chelating tags enhance background-free imaging due to the short fluorescent lifetimes of cellular autofluorescence. In this study, we used both methods to target E-selectin, a transmembrane glycoprotein that is activated by inflammation, to demonstrate background-free fluorescent staining in fixed endothelial cells. Our findings indicate that both FND and Europium based staining can improve fluorescent bio-imaging capabilities by reducing competition with cellular autofluorescence. 30 nm nanodiamonds coated with the E-selectin antibody was found to enable the most sensitive detective of E-selectin in inflamed cells, with a 40-fold increase in intensity detected.
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.BRAINRES.2015.01.049
Abstract: Hypotensive drugs have been used to identify central neurons that mediate compensatory baroreceptor reflex responses. Such drugs also increase blood glucose. Our aim was to identify the neurochemical phenotypes of sympathetic preganglionic neurons (SPN) and adrenal chromaffin cells activated following hydralazine (HDZ 10mg/kg) administration in rats, and utilize this and SPN target organ destination to ascribe their function as cardiovascular or glucose regulating. Blood glucose was measured and adrenal chromaffin cell activation was assessed using c-Fos immunoreactivity (-ir) and phosphorylation of tyrosine hydroxylase, respectively. The activation and neurochemical phenotype of SPN innervating the adrenal glands and celiac ganglia were determined using the retrograde tracer cholera toxin B subunit, in combination with in situ hybridization and immunohistochemistry. Blood glucose was elevated at multiple time points following HDZ administration but little evidence of chromaffin cell activation was seen suggesting non-adrenal mechanisms contribute to the sustained hyperglycemia. 16±0.1% of T4-T11 SPN contained c-Fos and of these: 24.3±1.4% projected to adrenal glands and 29±5.5% projected to celiac ganglia with the rest innervating other targets. 62.8±1.4% of SPN innervating adrenal glands were activated and 29.9±3.3% expressed PPE mRNA whereas 53.2±8.6% of SPN innervating celiac ganglia were activated and 31.2±8.8% expressed PPE mRNA. CART-ir SPN innervating each target were also activated and did not co-express PPE mRNA. Neurochemical coding reveals that HDZ administration activates both PPE+SPN, whose activity increase glucose mobilization causing hyperglycemia, as well as CART+SPN whose activity drive vasomotor responses mediated by baroreceptor unloading to raise vascular tone and heart rate.
Publisher: SPIE
Date: 04-03-2019
DOI: 10.1117/12.2509582
Publisher: Wiley
Date: 04-2016
DOI: 10.1111/JNE.12337
Abstract: The neuropeptide oxytocin attenuates reward and abuse for the psychostimulant meth hetamine (METH). Recent findings have implicated the nucleus accumbens (NAc) core and subthalamic nucleus (STh) in oxytocin modulation of acute METH reward and relapse to METH-seeking behaviour. Surprisingly, the oxytocin receptor (OTR) is only modestly involved in both regions in oxytocin attenuation of METH-primed reinstatement. Coupled with the limited investigation of the role of the OTR in psychostimulant-induced behaviours, we primarily investigated whether there are cellular changes to the OTR in the NAc core and STh, as well as changes to oxytocin plasma levels, after chronic METH i.v. self-administration (IVSA) and after extinction of drug-taking. An additional aim was to examine whether changes to central corticotrophin-releasing factor (CRF) and plasma corticosterone levels were also apparent because of the interaction of oxytocin with stress-regulatory mechanisms. Male Sprague-Dawley rats were trained to lever press for i.v. METH (0.1 mg/kg/infusion) under a fixed-ratio 1 schedule or received yoked saline infusions during 2-h sessions for 20 days. An additional cohort of rats underwent behavioural extinction for 15 days after METH IVSA. Subsequent to the last day of IVSA or extinction, blood plasma was collected for enzyme immunoassay, and immunofluorescence was conducted on NAc core and STh coronal sections. Rats that self-administered METH had higher oxytocin plasma levels, and decreased OTR-immunoreactive (-IR) fibres in the NAc core than yoked controls. In animals that self-administered METH and underwent extinction, oxytocin plasma levels remained elevated, OTR-IR fibre density increased in the STh, and a trend towards normalisation of OTR-IR fibre density was evident in the NAc core. CRF-IR fibre density in both brain regions and corticosterone plasma levels did not change across treatment groups. These findings demonstrate that oxytocin systems, both centrally within the NAc core and STh, as well as peripherally through plasma measures, are dysregulated after METH abuse.
Publisher: MDPI AG
Date: 05-06-2023
DOI: 10.3390/BIOENGINEERING10060687
Abstract: Additive manufacturing (3D printing) and computer-aided design (CAD) still have limited uptake in biomedical and bioengineering research and education, despite the significant potential of these technologies. The utility of organ-scale 3D-printed models of living structures is widely appreciated, while the workflows for microscopy data translation into tactile accessible replicas are not well developed yet. Here, we demonstrate an accessible and reproducible CAD-based methodology for generating 3D-printed scalable models of human cells cultured in vitro and imaged using conventional scanning confocal microscopy with fused deposition modeling (FDM) 3D printing. We termed this technology CiTo-3DP (Cells-in-Touch for 3D Printing). As a proof-of-concept, we created dismountable CiTo-3DP models of human epithelial, mesenchymal, and neural cells by using selectively stained nuclei and cytoskeletal components. We also provide educational and research context for the presented cellular models. In the future, the CiTo-3DP approach can be adapted to different imaging and 3D printing modalities and comprehensively present various cell types, subcellular structures, and extracellular matrices. The resulting CAD and 3D printed models could be used for a broad spectrum of education and research applications.
Publisher: Springer Science and Business Media LLC
Date: 24-10-2020
DOI: 10.1007/S12035-019-01791-7
Abstract: Polysialic acid (polySia), a long homopolymer of 2,8-linked sialic acids, is abundant in the embryonic brain and is restricted largely in adult brain to regions that exhibit neurogenesis and structural plasticity. In the central nervous system (CNS), polySia is highly important for cell-cell interactions, differentiation, migration and cytokine responses, which are critical neuronal functions regulating intercellular interactions that underlie immune signalling in the CNS. In recent reports, a metabolite of morphine, morphine-3-glucuronide (M3G), has been shown to cause immune signalling in the CNS. In this study, we compared the effects of neurite growth factor (NGF), lipopolysaccharide (LPS) and M3G exposure on the expression of polySia in PC12 cells using immunocytochemistry and Western blot analysis. PolySia was also extracted from stimulated cell proteins by endo-neuraminidase digestion and quantitated using fluorescent labelling followed by HPLC analysis. PolySia expression was significantly increased following NGF, M3G or LPS stimulation when compared with unstimulated cells or cells exposed to the TLR4 antagonist LPS-RS. Additionally, we analyzed the effects of test agent exposure on cell migration and the oxidative stress response of these cells in the presence and absence of polySia expression on their cell surface. We observed an increase in oxidative stress in cells without polySia as well as following M3G or LPS stimulation. Our study provides evidence that polySia expression in neuronal-like PC12 cells is influenced by M3G and LPS exposure alike, suggestive of a role of TLR4 in triggering these events.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2007
DOI: 10.1161/HYPERTENSIONAHA.107.089748
Abstract: We demonstrated recently that superoxide anion levels are elevated in prevertebral sympathetic ganglia of deoxycorticosterone acetate–salt hypertensive rats and that this superoxide anion is generated by reduced nicotinamide-adenine dinucleotide phosphate oxidase. In this study we compared the reduced nicotinamide-adenine dinucleotide phosphate oxidase enzyme system of dorsal root ganglion (DRG) and sympathetic celiac ganglion (CG) and its regulation in hypertension. The reduced nicotinamide-adenine dinucleotide phosphate oxidase activity of ganglion extracts was measured using fluorescence spectrometry of dihydroethidine the activity in hypertensive dorsal root ganglion was 34% lower than in normotensive DRG. In contrast, activity was 79% higher in hypertensive CG than normotensive CG. mRNA for the oxidase subunits NOX1, NOX2, NOX4, p47 phox , and p22 phox were present in both CG and DRG mRNA for NOX4 was significantly higher in CG than in DRG. The levels of mRNA and protein expression of the membrane-bound catalytic subunit p22 phox and of the regulatory subunits p47 phox and Rac-1 were measured in CG and DRG in normotensive and hypertensive rats. p22 phox mRNA and protein expression was greater in CG of hypertensive rats but not in DRG. Compared with normotensive controls, p47 phox mRNA and protein, as well as Rac-1 protein, were significantly decreased in hypertensive DRG but not in CG. Immunohistochemical staining of p47 phox showed translocation from cytoplasm to membrane in hypertensive CG but not in hypertensive DRG. This suggests that reduced nicotinamide-adenine dinucleotide phosphate oxidase activation in sympathetic neurons and sensory neurons is regulated in opposite directions in hypertension. This differential regulation may contribute to unbalanced vasomotor control and enhanced vasoconstriction in the splanchnic circulation.
Publisher: SPIE
Date: 26-04-2016
DOI: 10.1117/12.2209249
Publisher: Springer Science and Business Media LLC
Date: 16-12-2015
DOI: 10.1038/SREP17985
Abstract: The differentiation potential of pluripotent embryonic stem cells (ESCs) can be manipulated via serum and medium conditions for direct cellular development or to maintain a naïve ground state. The self-renewal state of ESCs can thus be induced by adding inhibitors of mitogen activated protein kinase (MAPK) and glycogen synthase kinase-3 (Gsk3), known as 2 inhibitors (2i) treatment. We have used a shotgun proteomics approach to investigate differences in protein expressions between 2i- and serum-grown mESCs. The results indicated that 164 proteins were significantly upregulated and 107 proteins downregulated in 2i-grown cells compared to serum. Protein pathways in 2i-grown cells with the highest enrichment were associated with glycolysis and gluconeogenesis. Protein pathways related to organ development were downregulated in 2i-grown cells. In serum-grown ESCs, protein pathways involved in integrin and focal adhesion and signaling proteins involved in the actin cytoskeleton regulation were enriched. We observed a number of nuclear proteins which were mostly involved in self-renewal maintenance and were expressed at higher levels in 2i compared to serum - Dnmt1, Map2k1, Parp1, Xpo4, Eif3g, Smarca4/Brg1 and Smarcc1/Baf155. Collectively, the results provided an insight into the key protein pathways used by ESCs in the ground state or metastable conditions through 2i or serum culture medium, respectively.
Publisher: Elsevier BV
Date: 12-2013
Publisher: Wiley
Date: 19-06-2013
DOI: 10.1002/CNE.23310
Abstract: Glucoprivation or hypoglycemia induces a range of counterregulatory responses, including glucose mobilization, reduced glucose utilization, and de novo glucose synthesis. These responses are mediated in part by the sympathetic nervous system. The aim of this study was to determine the chemical codes of sympathetic preganglionic neurons (SPN) activated by glucoprivation, induced by 2-deoxy-D-glucose (2DG). SPN controlling the adrenal glands and celiac ganglia, which ultimately can innervate the liver and pancreas, were targeted together with the superior cervical ganglia (control). 23.9% ± 1.3% of SPN in the T4-T11 region contained c-Fos immunoreactivity following 2DG 70.3% ± 1.8% of SPN innervating the adrenal glands and 37.4% ± 3% of SPN innervating celiac ganglia were activated. 14.8% ± 3.5% of SPN (C8-T3) innervating superior cervical ganglia were activated. In the C8-T3 region 55% ± 10% of SPN activated contained PPCART, with only 12% ± 3% expressing PPE mRNA, whereas, in the T4-T11 region, 78% ± 4% contained PPE, with only 6.0% ± 0.6% expressing PPCART mRNA. Thus CART is not involved in glucose mobilization. Two chemically distinct populations of SPN (PPE⁺ 57.4% ± 5%, PPE⁻ ∼40%) were identified to regulate adrenaline release in response to glucoprivation. Multiple chemically distinct SPN populations innervating a specific target could suggest their graded recruitment. The two distinct populations of SPN (PPE⁺ 67.6% ± 9%, PPE⁻ ∼30%) projecting to celiac ganglia activated by glucoprivation could direct pancreatic and hepatic or other counterregulatory responses. Nearly all SPN that expressed PPE mRNA and projected to the adrenal glands or celiac ganglia were activated, suggesting a role for the inhibitory peptide enkephalin in responses evoked by glucoprivation.
Publisher: Optica Publishing Group
Date: 31-07-2020
DOI: 10.1364/OE.400651
Abstract: Upconversion nanoparticles (UCNPs) are becoming increasingly popular as biological markers as they offer photo-stable imaging in the near-infrared (NIR) biological transparency window. Imaging at NIR wavelengths benefits from low auto-fluorescence background and minimal photo-damage. However, as the diffraction limit increases with the wavelength, the imaging resolution deteriorates. To address this limitation, recently two independent approaches have been proposed for imaging UCNPs with sub-diffraction resolution, namely stimulated emission-depletion (STED) microscopy and super linear excitation-emission (uSEE) microscopy. Both methods are very sensitive to the UCNP composition and the imaging conditions, i.e. to the excitation and depletion power. Here, we demonstrate that the imaging conditions can be chosen in a way that activates both super-resolution regimes simultaneously when imaging NaYF 4 :Yb,Tm UCNPs. The combined uSEE-STED mode benefits from the advantages of both techniques, allowing for imaging with lateral resolution about six times better than the diffraction limit due to STED and simultaneous improvement of the axial resolution about twice over the diffraction limit due to uSEE. Conveniently, at certain imaging conditions, the uSEE-STED modality can achieve better resolution at four times lower laser power compared to STED mode, making the method appealing for biological applications. We illustrate this by imaging UCNPs functionalized by colominic acid in fixed neuronal phenotype cells.
Publisher: Portland Press Ltd.
Date: 17-12-2019
DOI: 10.1042/BST20180330
Abstract: Glycosylation, the enzymatic process by which glycans are attached to proteins and lipids, is the most abundant and functionally important type of post-translational modification associated with brain development, neurodegenerative disorders, psychopathologies and brain cancers. Glycan structures are erse and complex however, they have been detected and targeted in the central nervous system (CNS) by various immunohistochemical detection methods using glycan-binding proteins such as anti-glycan antibodies or lectins and/or characterized with analytical techniques such as chromatography and mass spectrometry. The glycan structures on glycoproteins and glycolipids expressed in neural stem cells play key roles in neural development, biological processes and CNS maintenance, such as cell adhesion, signal transduction, molecular trafficking and differentiation. This brief review will highlight some of the important findings on differential glycan expression across stages of CNS cell differentiation and in pathological disorders and diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, amyotrophic lateral sclerosis, schizophrenia and brain cancer.
Publisher: Elsevier BV
Date: 10-2013
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.CARBPOL.2018.05.038
Abstract: A hydrothermal microwave pretreatment was established to facilitate the enzymatic production of soluble bioactive β-1,3-glucans from the recalcitrant substrate paramylon. The efficacy of this pretreatment was monitored with a newly developed direct Congo Red dye-based assay over a range of temperatures. Microwave pretreatment at 170 °C for 2 min resulted in a significantly enhanced enzymatic hydrolysis of paramylon. The action of endo-β-1,3- and exo- β-1,3-glucanases on the microwave-pretreated paramylon produced soluble β-1,3-glucans with degrees of polymerisation (DP) ranging from 2-59 and 2-7, respectively. In comparison, acid-mediated hydrolysis of untreated paramylon resulted in β-1,3-glucans with a DP range of 2-38. The hydrolysates were assayed on their immunostimulatory effect on murine macrophages by measuring the production of the inflammation-linked marker tumour necrosis factor alpha (TNFα) using immunofluorescence. All of the tested hydrolysis products were shown to induce TNFα production, with the most significant immunostimulatory effect observed with the hydrolysate from the exo-β-1,3-glucanase treatment.
Publisher: American Chemical Society (ACS)
Date: 22-07-2015
DOI: 10.1021/ACS.JPROTEOME.5B00512
Abstract: Although it is apparent that chromosome complement mediates sexually dimorphic expression patterns of some proteins that lead to functional differences, there has been insufficient evidence following the manipulation of the male-specific region of the Y chromosome (MSY) gene expression during neural development. In this study, we profiled the expression of 23 MSY genes and 15 of their X-linked homologues during neural cell differentiation of NTERA-2 human embryonal carcinoma cell line (NT2) cells in three different developmental stages using qRT-PCR, Western blotting, and immunofluorescence. The expression level of 12 Y-linked genes significantly increased over neural differentiation, including RBMY1, EIF1AY, DDX3Y, HSFY1, BPY2, PCDH11Y, UTY, RPS4Y1, USP9Y, SRY, PRY, and ZFY. We showed that siRNA-mediated knockdown of DDX3Y, a DEAD box RNA helicase enzyme, in neural progenitor cells impaired cell cycle progression and increased apoptosis, consequently interrupting differentiation. Label-free quantitative shotgun proteomics based on a spectral counting approach was then used to characterize the proteomic profile of the cells after DDX3Y knockdown. Among 917 reproducibly identified proteins detected, 71 proteins were differentially expressed following DDX3Y siRNA treatment compared with mock treated cells. Functional grouping indicated that these proteins were involved in cell cycle, RNA splicing, and apoptosis, among other biological functions. Our results suggest that MSY genes may play an important role in neural differentiation and demonstrate that DDX3Y could play a multifunctional role in neural cell development, probably in a sexually dimorphic manner.
Publisher: Springer Science and Business Media LLC
Date: 16-08-2019
DOI: 10.1038/S41467-019-11603-0
Abstract: Sub-diffraction microscopy enables bio-imaging with unprecedented clarity. However, most super-resolution methods require complex, costly purpose-built systems, involve image post-processing and struggle with sub-diffraction imaging in 3D. Here, we realize a conceptually different super-resolution approach which circumvents these limitations and enables 3D sub-diffraction imaging on conventional confocal microscopes. We refer to it as super-linear excitation-emission (SEE) microscopy, as it relies on markers with super-linear dependence of the emission on the excitation power. Super-linear markers proposed here are upconversion nanoparticles of NaYF 4 , doped with 20% Yb and unconventionally high 8% Tm, which are conveniently excited in the near-infrared biological window. We develop a computational framework calculating the 3D resolution for any viable scanning beam shape and excitation-emission probe profile. Imaging of colominic acid-coated upconversion nanoparticles endocytosed by neuronal cells, at resolutions twice better than the diffraction limit both in lateral and axial directions, illustrates the applicability of SEE microscopy for sub-cellular biology.
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.NEUROPHARM.2016.08.038
Abstract: Psychotic disorders, such as schizophrenia, are characterized by prevalent and persistent executive deficits that are believed to be the result of dysfunctional inhibitory gamma-aminobutyric acid (GABA) processing of the prefrontal cortex (PFC). Meth hetamine (METH) is a commonly used psychostimulant that can induce psychotic and cognitive symptoms that are indistinguishable to schizophrenia, suggesting that METH-induced psychosis may have a similar GABAergic profile of the PFC. As the PFC consists of multiple subregions, the aim of the current study was to investigate changes to GABAergic mRNA expression in the prelimbic (PRL) and orbitofrontal (OFC) cortices of the PFC in rats sensitized to repeated METH administration. Male Sprague Dawley rats underwent daily METH or saline injections for 7 days. Following 14 days of withdrawal, rats were challenged with acute METH administration, RNA was isolated from the PRL and OFC and quantitative PCR was used to compare the relative expression of GABA enzymes, transporters, metabolites and receptor subunits. GAD
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2NA00036A
Abstract: Nanodiamonds were coated in lectins to target glycan receptors on astrocytes, neurons and microglia. The uptake in each cell type was variable depending on their coating of Aleuria aurantia lectin, wheat germ agglutinin or tomato lectin.
Publisher: Wiley
Date: 23-06-2016
Publisher: Elsevier BV
Date: 08-2012
DOI: 10.1016/J.NEUROSCIENCE.2012.05.037
Abstract: About 860 G-protein-coupled receptors (GPCRs) mediate their actions via heterotrimeric G-proteins. Their activation releases Gα from Gβλ subunits. The type of Gα subunit dictates the major signalling proteins involved: adenylyl cyclase, PLC and rhoGEF. The rostral ventrolateral medulla (RVLM), containing the rostral C1 (rC1) cell group, sets and maintains the tonic and reflex control of blood pressure and a plethora of inputs converge onto these neurons. We determined the relative abundance of 10 Gα subunit mRNAs, representing the four major families, within the RVLM, using quantitative RT-PCR. In situ hybridisation (ISH) combined with immunohistochemistry (IHC) was used to quantify and compare this expression in rC1 with that in the A1 and A5 cell groups. The relative abundance of Gα subunit mRNAs and a comparison of gene expression levels were quantitatively determined in normotensive and hypertensive rat strains. All 10 Gα mRNAs were detected in the RVLM of Sprague-Dawley (SD) rats with relative abundance such that Gαs>Gαi2>Gαo>Gαq>GαL>Gα11>Gαi3>Gαi1>Gα12>Gα13. The high abundance of Gα mRNAs signalling via adenylyl cyclase indicates the importance of associated GPCRs. Within the rC1 and A1 groups similar differential Gα mRNA expression profiles were seen with Gαs being found in all rC1 cells, Gα11 absent and Gαi3 rarely expressed. Thus functionally distinct subgroups exist within the rC1 and A1 cell groups as differing distributions of Gα subunits must reflect the array of GPCRs that influence their activity. In contrast, all A5 cells expressed all Gα mRNAs suggesting a functionally homogeneous group. When the 10 Gα mRNAs of the RVLM in spontaneously hypertensive rats (SHR) were compared quantitatively to Wistar-Kyoto (WKY), only Gαs and Gα12 were significantly elevated. However when the expression in normotensive SD and WKY was compared with SHR no significant differences were evident. These findings demonstrate a range of GPCR signalling capabilities in brainstem neurons important for homeostasis and suggest a prominent role for signalling via adenylyl cyclase.
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.PNPBP.2017.03.018
Abstract: Schizophrenia is associated with significant pathophysiological changes to interneurons within the prefrontal cortex (PFC), with mRNA and protein changes associated with the GABA network localized to specific interneuron subtypes. Meth hetamine is a commonly abused psychostimulant that can induce chronic psychosis and symptoms that are similar to schizophrenia, suggesting that chronic METH induced psychosis may be associated with similar brain pathology to schizophrenia in the PFC. The aim of this study, therefore, was to examine mRNA expression of interneuron markers across two regions of the PFC (prelimbic (PRL) and orbitofrontal cortices (OFC)) following METH sensitization, an animal model of METH psychosis. We also studied the association between GABA mRNA expression and interneuronal mRNA expression to identify whether particular changes to the GABA network could be localized to a specific inhibitory cellular phenotype. METH sensitization increased the transcriptional expression of calbindin, calretinin, somatostatin, cholecyctokinin and vasoactive intestinal peptide in the PRL while parvalbumin, calbindin, cholectokinin and vasoactive intestinal peptide were upregulated in the OFC. Based on our previous findings, we also found significant correlations between GAD
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TB00445A
Abstract: The protein corona of nanodiamonds is dominated by low molecular weight proteins and is largely independent of surface chemistry. The pre-incubation of nanodiamonds in serum and the formation of a protein corona decrease the production of reactive oxygen species, increasing the cell viability of macrophages.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2010
Publisher: Springer Science and Business Media LLC
Date: 08-10-2013
DOI: 10.1007/S00429-013-0642-3
Abstract: Hypoglycemia elicits physiological and behavioral responses which are mediated in part by neurons within the ventrolateral medulla (VLM). The present study describes the neurochemistry of neurons activated by glucoprivation (2-deoxy-D-glucose, 2DG), specifically those within regions containing the A1, caudal C1 (cC1) and rostral C1 (rC1) cell groups. 2DG induced c-Fos immunoreactivity throughout the VLM. Activated neurons expressing prepro-cocaine and hetamine-regulated transcript (PPCART), neuropeptide Y (NPY), glutamic acid decarboxylase (GAD67) or prepro-enkephalin (PPE) mRNA and/or immunoreactivity (-ir) for tyrosine hydroxylase (TH) were identified. TH(+) neurons were recruited in a dose-dependent manner. At high doses of 2DG [400 mg/kg, (n = 6)], 76 ± 1.2 % of activated neurons were TH(+) representing 52 ± 1.3 % of the total TH population. Virtually all activated neurons in the A1 and cC1 regions but only 60 % in the rC1 region were TH(+). Within the A1 region, TH(+), TH(+)NPY(+) and TH(+)NPY(+)PPE(+) subpopulations were activated and likely regulate vasopressin, oxytocin, and corticotrophin releasing hormone (CRH) from the hypothalamus. Within the cC1 region, non-TH neurons, TH(+)NPY(+), TH(+)NPY(+)PPCART(+), and TH(+)NPY(+)PPE(+) subpopulations were activated, likely regulating autonomic hypothalamic neurons or CRH and thyrotropin releasing hormone secretion. Within the rC1 region, non-TH neurons (40 % of those activated) were predominantly PPE(+) and were recruited by higher 2DG doses. Of the TH(+) activated neurons in the rC1 region, many expressed PPCART and half expressed NPY. The activated spinally projecting population was almost entirely TH(+)PPCART(+) and is likely to regulate adrenaline and glucagon release. These data indicate that glucoprivation activates at least nine phenotypically distinct populations of neurons in the VLM.
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.BBI.2016.04.014
Abstract: The importance of neuro-immune interactions in both physiological and pathophysiological states cannot be overstated. As our appreciation for the neuroimmune nature of the brain and spinal cord grows, so does our need to extend the spatial and temporal resolution of our molecular analysis techniques. Current imaging technologies applied to investigate the actions of the neuroimmune system in both health and disease states have been adapted from the fields of immunology and neuroscience. While these classical techniques have provided immense insight into the function of the CNS, they are however, inherently limited. Thus, the development of innovative methods which overcome these limitations are crucial for imaging and quantifying acute and chronic neuroimmune responses. Therefore, this review aims to convey emerging novel and complementary imaging technologies in a form accessible to medical scientists engaging in neuroimmune research.
Publisher: Springer Science and Business Media LLC
Date: 21-03-2019
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.BBR.2015.10.026
Abstract: Inhibitory gamma-aminobutyric acid (GABA)-mediated neurotransmission plays an important role in the regulation of the prefrontal cortex (PFC), with increasing evidence suggesting that dysfunctional GABAergic processing of the PFC may underlie certain deficits reported across psychotic disorders. Meth hetamine (METH) is a psychostimulant that induces chronic psychosis in a subset of users, with repeat administration producing a progressively increased vulnerability to psychotic relapse following subsequent drug administration (sensitization). The aim here was to investigate changes to GABAergic mRNA expression in the PFC of rats sensitized to METH using quantitative polymerase chain reaction (qPCR). Male Sprague-Dawley rats (n=12) underwent repeated meth hetamine (intraperitoneal (i.p.) or saline injections for 7 days. Following 14 days of withdrawal, rats were challenged with acute meth hetamine (1mg/kg i.p.) and RNA was isolated from the PFC to compare the relative mRNA expression of a range of GABA enzymes, transporters and receptors subunits. METH challenge resulted in a significant sensitized behavioral (locomotor) response in METH pre-treated animals compared with saline pre-treated controls. The mRNAs of transporters (GAT1 and GAT3), ionotropic GABAA receptor subunits (α3 and β1), together with the metabotropic GABAB1 receptor, were upregulated in the PFC of sensitized rats compared with saline controls. These findings indicate that GABAergic mRNA expression is significantly altered at the pre and postsynaptic level following sensitization to METH, with sensitization resulting in the transcriptional upregulation of several inhibitory genes. These changes likely have significant consequences on GABA-mediated neurotransmission in the PFC and may underlie certain symptoms conserved across psychotic disorders, such as executive dysfunction.
Publisher: IEEE
Date: 06-2019
Publisher: Wiley
Date: 29-03-2017
DOI: 10.1002/CNE.24203
Abstract: Previous studies have demonstrated that a range of stimuli activate neurons, including catecholaminergic neurons, in the ventrolateral medulla. Not all catecholaminergic neurons are activated and other neurochemical content is largely unknown hence whether stimulus specific populations exist is unclear. Here we determine the neurochemistry (using in situ hybridization) of catecholaminergic and noncatecholaminergic neurons which express c-Fos immunoreactivity throughout the rostrocaudal extent of the ventrolateral medulla, in Sprague Dawley rats treated with hydralazine or saline. Distinct neuronal populations containing PPCART, PPPACAP, and PPNPY mRNAs, which were largely catecholaminergic, were activated by hydralazine but not saline. Both catecholaminergic and noncatecholaminergic neurons containing preprotachykinin and prepro-enkephalin (PPE) mRNAs were also activated, with the noncatecholaminergic population located in the rostral C1 region. Few GlyT2 neurons were activated. A subset of these data was then used to compare the neuronal populations activated by 2-deoxyglucose evoked glucoprivation (Brain Structure and Function (2015) 220:117). Hydralazine activated more neurons than 2-deoxyglucose but similar numbers of catecholaminergic neurons. Commonly activated populations expressing PPNPY and PPE mRNAs were defined. These likely include PPNPY expressing catecholaminergic neurons projecting to vasopressinergic and corticotrophin releasing factor neurons in the paraventricular nucleus, which when activated result in elevated plasma vasopressin and corticosterone. Stimulus specific neurons included noncatecholaminergic neurons and a few PPE positive catecholaminergic neuron but neurochemical codes were largely unidentified. Reasons for the lack of identification of stimulus specific neurons, readily detectable using electrophysiology in anaesthetized preparations and for which neural circuits can be defined, are discussed.
Publisher: Elsevier BV
Date: 10-2010
DOI: 10.1016/J.NEUROSCIENCE.2010.07.047
Abstract: Chemical coding of sympathetic preganglionic neurons (SPN) suggests that the chemical content of subpopulations of SPN can define their function. Since neuropeptides, once synthesized are transported to the axon terminal, most demonstrated chemical coding has been identified using immunoreactive terminals at the target organ. Here, we use a different approach to identify and quantify the subpopulations of SPN that contain the mRNA for pituitary adenylate cyclase activating polypeptide (PACAP) or enkephalin. Using double-labeled immunohistochemistry combined with in situ hybridization (ISH) we firstly identified the distribution of these mRNAs in the spinal cord and determined quantitatively, in Sprague-Dawley rats, that many SPN at the T4-T10 spinal level contain preproPACAP (PPP+, 80 ± 3%, n=3), whereas a very small percentage contain preproenkephalin (PPE+, 4 ± 2%, n=4). A similar neurochemical distribution was found at C8-T3 spinal level. These data suggest that PACAP potentially regulates a large number of functions dictated by SPN whereas enkephalins are involved in few functions. We extended the study to explore those SPN that control adrenal chromaffin cells. We found 97 ± 5% of adrenally projecting SPN (AP-SPN) to be PPP+ (n=4) with only 47 ± 3% that were PPE+ (n=5). These data indicate that adrenally projecting PACAPergic SPN regulate both adrenal adrenaline (Ad) and noradrenaline (NAd) release whereas the enkephalinergic SPN subpopulation must control a (sub) population of chromaffin cells - most likely those that release Ad. The sensory innervation of the adrenal gland was also determined. Of the few adrenally projecting dorsal root ganglia (AP-DRG) observed, 74 ± 12% were PPP+ (n=3), whereas 1 ± 1% were PPE+ (n=3). Therefore, if sensory neurons release peptides to the adrenal medulla, PACAP is most likely involved. Together, these data provide a neurochemical basis for differential control of sympathetic outflow particularly that to the adrenal medulla.
Publisher: American Physiological Society
Date: 09-2008
DOI: 10.1152/AJPREGU.00190.2008
Abstract: The cardiac neuronal norepinephrine (NE) transporter (NET) in sympathetic neurons is responsible for uptake of released NE from the neuroeffector junction. The purpose of this study was to assess the chamber distribution of cardiac NET protein measured using [ 3 H]nisoxetine binding in rat heart membranes and to correlate NE content to NET amount. In whole mounts of atria, NET was colocalized in nerve fibers with tyrosine hydroxylase (TH) immunoreactivity. NE content expressed as micrograms NE per gram tissue was lowest in the ventricles however, NET binding was significantly higher in the left ventricle than the right ventricle and atria ( P 0.05), resulting in a significant negative correlation ( r 2 = 0.922 P 0.05) of NET to NE content. The neurotoxin 6-hydroxydopamine, an NET substrate, reduced NE content more in the ventricles than the atria, demonstrating functional significance of high ventricular NET binding. In summary, there is a ventricular predominance of NET binding that corresponds to a high NE reuptake capacity in the ventricles, yet negatively correlates to tissue NE content.
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.JPROT.2017.02.007
Abstract: Male infertility accounts for half of the infertility problems experienced by couples. Azoospermia, having no measurable level of sperm in seminal fluid, is one of the known conditions resulting in male infertility. In order to elucidate the complex molecular mechanisms causing male azoospermia, label-free quantitative shotgun proteomics was carried out on testicular tissue specimens from patients with obstructive azoospermia and non-obstructive azoospermia, including maturation arrest (MA) and Sertoli cell only syndrome (SCOS). The abundance of 520 proteins was significantly changed across three groups of s les. We were able to identify several functional biological pathways enriched in azoospermia s les and confirm selected differentially abundant proteins, using multiple histological methods. The results revealed that cell cycle and proteolysis, and RNA splicing were the most significant biological processes impaired by the substantial suppression of proteins related to the aforementioned categories in SCOS tissues. In the MA patient testes, generation of precursor metabolites and energy as well as oxidation-reduction were the most significantly altered processes. Novel candidate proteins identified in this study include key transcription factors, many of which have not previously been shown to be associated with azoospermia. Our findings can provide substantial insights into the molecular regulation of spermatogenesis and human reproduction. The obtained data showed a drastic suppression of proteins involved in spliceosome, cell cycle and proteasome proteins, as well as energy and metabolic production in Sertoli cell only syndrome testis tissue, and to a lesser extent in maturation arrest s les. Moreover, we identified new transcription factors that are highly down-regulated in SCOS and MA patients, thus helping to understand the molecular complexity of spermatogenesis in male infertility. Our findings provide novel candidate protein targets associated with SCOS or MA azoospermia.
Publisher: Elsevier BV
Date: 10-2019
Publisher: Oxford University Press (OUP)
Date: 28-08-2018
Abstract: Post-translational modification of proteins namely glycosylation influences cellular behavior, structural properties and interactions including during ovarian follicle development and atresia. However, little is known about protein glycosylation changes occurring in diabetes mellitus in ovarian tissues despite the well-known influence of diabetes on the outcome of successful embryo implantation. In our study, the use of PGC chromatography-ESI mass spectrometry in negative ion mode enabled the identification of 138 N-glycans and 6 O-glycans on the proteins of Streptozotocin-induced (STZ) diabetic mouse ovarian tissues (n = 3). Diabetic mouse ovaries exhibited a relative decrease in sialylation, fucosylation and, to a lesser extent, branched N-linked glycan structures, as well as an increase in oligomannose structures on their proteins, compared with nondiabetic mouse ovaries. Changes in N-glycans occurred in the diabetic liver tissue but were more evident in diabetic ovarian tissue of the same mouse, suggesting an organ-specific effect of diabetes mellitus on protein glycosylation. Although at a very low amount, O-GalNAc glycans of mice ovaries were present as core type 1 and core type 2 glycans with a relative increase in the NeuGc:NeuAc ratio as the most significant difference between control and diabetic ovarian tissues. STZ-treated mice also showed a trend towards an increase in TNF-α and IL1-B inflammatory cytokines, which have previously been shown to influence protein glycosylation.
Location: United States of America
Start Date: 02-2018
End Date: 2023
Amount: $365,058.00
Funder: Australian Research Council
View Funded Activity