ORCID Profile
0000-0002-3296-7270
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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.
Analytical Spectrometry | Organometallic Chemistry | Synchrotrons; Accelerators; Instruments and Techniques | Analytical Chemistry | Other Chemical Sciences | Bioinorganic Chemistry
Expanding Knowledge in the Chemical Sciences | Expanding Knowledge in the Biological Sciences | Neurodegenerative Disorders Related to Ageing |
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7AN01615H
Abstract: Latent fingermark chemistry revealed by Raman microscopy and Synchrotron ATR-FTIR.
Publisher: Elsevier BV
Date: 07-2017
Publisher: Elsevier BV
Date: 10-2011
Publisher: Wiley
Date: 03-05-2022
Abstract: Well‐defined copolymers containing luminescent iridium and hybrid iridium/rhenium fragments are prepared utilizing parent poly( n ‐butyl acrylamide‐ co ‐ N ‐(1 H ‐tetrazol‐5‐yl) acrylamide) as macromolecular chelating species. The parent (co)polymers are prepared via the modification of a precursor poly(pentafluorophenyl acrylate) (polyPFPA) homopolymer, prepared by reversible addition‐fragmentation chain transfer polymerization, with n ‐butylamine and 5‐aminotetrazole. Reaction of the parent copolymers with [Ir 2 (ppy) 4 ( μ −Cl 2 )] (ppy = 2‐phenylpyridine) yields modified copolymers containing the Ir(ppy) 2 fragment as a pendent group. Attachment of the Ir species is confirmed by a combination of photophysical studies, UV–Vis spectroscopy, and visually under irradiation with UV light. Importantly, it is demonstrated that the chelation of the Ir(ppy) 2 fragment to a polymeric scaffold does not impact the fundamental photophysical properties of the Ir species. Attachment of a second luminescent metal species, Re(CO) 3 (phen) (phen = 1,10‐phenanthroline), gives hybrid materials containing Re(I) and Ir(III). The photophysical properties of these hybrid materials are consistent with the presence of both metal species and indicate the occurrence of energy transfer phenomena from the polymer‐bound Ir to Re metal centers. Finally, it is demonstrated that the Ir modified polymers and the Ir/Re hybrid materials offer potential in tissue imaging applications with scope to tune both luminescent properties and biological specificity as evidenced from preliminary brain tissue staining experiments.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0AN00099J
Abstract: Halogenated BODIPY probes allow lipid imaging in brain tissue with different level of specificity for the white matter that are linked to the chemical identity of the halogen substituent.
Publisher: International Union of Crystallography (IUCr)
Date: 18-10-2012
Publisher: Frontiers Media SA
Date: 29-05-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0JA00323A
Abstract: Transition metal ions (Fe, Mn, Cu, Zn) are essential for healthy brain function, but common s le preparations, such as sucrose cryo-protection alter their distribution, which can confound studies of brain disease.
Publisher: Public Library of Science (PLoS)
Date: 14-09-2021
DOI: 10.1371/JOURNAL.PBIO.3001358
Abstract: Several lines of study suggest that peripheral metabolism of amyloid beta (Aß) is associated with risk for Alzheimer disease (AD). In blood, greater than 90% of Aß is complexed as an apolipoprotein, raising the possibility of a lipoprotein-mediated axis for AD risk. In this study, we report that genetic modification of C57BL/6J mice engineered to synthesise human Aß only in liver (hepatocyte-specific human amyloid (HSHA) strain) has marked neurodegeneration concomitant with capillary dysfunction, parenchymal extravasation of lipoprotein-Aß, and neurovascular inflammation. Moreover, the HSHA mice showed impaired performance in the passive avoidance test, suggesting impairment in hippoc al-dependent learning. Transmission electron microscopy shows marked neurovascular disruption in HSHA mice. This study provides causal evidence of a lipoprotein-Aß /capillary axis for onset and progression of a neurodegenerative process.
Publisher: American Chemical Society (ACS)
Date: 08-04-2019
DOI: 10.1021/ACS.LANGMUIR.8B04227
Abstract: The electroadsorption of proteins at aqueous-organic interfaces offers the possibility to examine protein structural rearrangements upon interaction with lipophilic phases, without modifying the bulk protein or relying on a solid support. The aqueous-organic interface has already provided a simple means of electrochemical protein detection, often involving adsorption and ion complexation however, little is yet known about the protein structure at these electrified interfaces. This work focuses on the interaction between proteins and an electrified aqueous-organic interface via controlled protein electroadsorption. Four proteins known to be electroactive at such interfaces were studied: lysozyme, myoglobin, cytochrome c, and hemoglobin. Following controlled protein electroadsorption onto the interface, ex situ structural characterization of the proteins by FTIR spectroscopy was undertaken, focusing on secondary structural traits within the amide I band. The structural variations observed included unfolding to form aggregated antiparallel β-sheets, where the rearrangement was specifically dependent on the interaction with the organic phase. This was supported by MALDI ToF MS measurements, which showed the formation of protein-anion complexes for three of these proteins, and molecular dynamic simulations, which modeled the structure of lysozyme at an aqueous-organic interface. On the basis of these findings, the modulation of protein secondary structure by interfacial electrochemistry opens up unique prospects to selectively modify proteins.
Publisher: Wiley
Date: 11-07-2019
Abstract: A family of three neutral iridium(III) tetrazolato complexes are investigated as bacterial imaging agents. The complexes offer a facile tuning of the emission colour from green (520 nm) to red (600 nm) in aqueous media, while keeping the excitation wavelength unchanged. The three complexes do not inhibit the bacterial growth of Bacillus Cereus, used as a model in this study, and exhibit extremely fast cellular uptake. After a minute incubation time, the nontoxic complexes show subcellular localisation in spherical structures identified as lipid vacuoles. Confocal Raman imaging has been exploited for the first time on live bacteria, to provide direct and label-free mapping of the lipid-enriched organelles within B. cereus, complementing the use of luminescent probes. Examination of the Raman spectra not only confirmed the presence of lipophilic inclusions in B. cereus but offered additional information about their chemical composition, suggesting that the lipid vacuoles may contain polyhydroxybutyrate (PHB).
Publisher: Springer International Publishing
Date: 2022
DOI: 10.1007/978-3-031-19863-2_3
Abstract: Fluorescence microscopy is a key tool in the biological sciences, which finds use as a routine laboratory technique (e.g., epifluorescence microscope) or more advanced confocal, two-photon, and super-resolution applications. Through continued developments in microscopy, and other analytical methods, the importance of lipids as constituents of subcellular organelles, signalling or regulating molecules continues to emerge. The increasing recognition of the importance of lipids to fundamental cell biology (in health and disease) has prompted the development of protocols and techniques to image the distribution of lipids in cells and tissues. A erse suite of spectroscopic and microscopy tools are continuously being developed and explored to add to the “toolbox” to study lipid biology. A relatively recent breakthrough in this field has been the development and subsequent application of metal-based luminescent complexes for imaging lipids in biological systems. These metal-based compounds appear to offer advantages with respect to their tunability of the photophysical properties, in addition to capabilities centred around selectively targeting specific lipid structures or classes of lipids. The presence of the metal centre also opens the path to alternative imaging modalities that might not be applicable to traditional organic fluorophores. This review examines the current progress and developments in metal-based luminescent complexes to study lipids, in addition to exploring potential new avenues and challenges for the field to take.
Publisher: Informa UK Limited
Date: 11-09-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0AN00642D
Abstract: Sulfur K-edge XANES was used to quantify changes in the taurine content of mouse muscle tissue in a model of muscular dystrophy. The changes could be associated with markers of disease pathology that were revealed by classical H& E histology.
Publisher: American Chemical Society (ACS)
Date: 19-07-2019
DOI: 10.1021/ACS.ANALCHEM.9B01843
Abstract: Fingermarks are an important form of crime-scene trace evidence however, their usefulness may be h ered by a variation in response or a lack of robustness in detection methods. Understanding the chemical composition and distribution within fingermarks may help explain variation in latent fingermark detection with existing methods and identify new strategies to increase detection capabilities. The majority of research in the literature describes investigation of organic components of fingermark residue, leaving the elemental distribution less well understood. The relative scarcity of information regarding the elemental distribution within fingermarks is in part due to previous unavailability of direct, micron resolution elemental mapping techniques. This capability is now provided at third generation synchrotron light sources, where X-ray fluorescence microscopy (XFM) provides micron or submicron spatial resolution and direct detection with sub-μM detection limits. XFM has been applied in this study to reveal the distribution of inorganic components within fingermark residue, including endogenous trace metals (Fe, Cu, Zn), diffusible ions (Cl
Publisher: Elsevier BV
Date: 07-2021
Publisher: American Chemical Society (ACS)
Date: 25-09-2012
DOI: 10.1021/CN300093G
Publisher: American Chemical Society (ACS)
Date: 11-09-2023
Publisher: Elsevier BV
Date: 07-2013
Publisher: IM Publications Open LLP
Date: 23-05-2022
DOI: 10.1255/SEW.2022.A11
Publisher: Oxford University Press (OUP)
Date: 12-2020
DOI: 10.1039/D0MT00198H
Abstract: Zinc is a prominent trace metal required for normal memory function. Memory loss and cognitive decline during natural ageing and neurodegenerative disease have been associated with altered brain-Zn homeostasis. Yet, the exact chemical pathways through which Zn influences memory function during health, natural ageing, or neurodegenerative disease remain unknown. The gap in the literature may in part be due to the difficulty to simultaneously image, and therefore, study the different chemical forms of Zn within the brain (or biological s les in general). To this extent, we have begun developing and optimising protocols that incorporate X-ray absorption near-edge structure (XANES) spectroscopic analysis of tissue at the Zn K-edge as an analytical tool to study Zn speciation in the brain. XANES is ideally suited for this task as all chemical forms of Zn are detected, the technique requires minimal s le preparation that may otherwise redistribute or alter the chemical form of Zn, and the Zn K-edge has known sensitivity to coordination geometry and ligand type. Herein, we report our initial results where we fit K-edge spectra collected from micro-dissected flash-frozen brain tissue, to a spectral library prepared from standard solutions, to demonstrate differences in the chemical form of Zn that exist between two brain regions, the hippoc us and cerebellum. Lastly, we have used an X-ray microprobe to demonstrate differences in Zn speciation within sub-regions of thin air-dried sections of the murine hippoc us but, the corresponding results highlight that the chemical form of Zn is easily perturbed by s le preparation such as tissue sectioning or air-drying, which must be a critical consideration for future work.
Publisher: Elsevier BV
Date: 09-2018
Publisher: Wiley
Date: 02-08-2021
Abstract: Analysis of the epicuticular wax layer on the surface of plant leaves can provide a unique window into plant physiology and responses to environmental stimuli. Well‐established analytical methodologies can quantify epicuticular wax composition, yet few methods are capable of imaging wax distribution in situ or in vivo. Here, the first report of Fourier transform infrared (FTIR) reflectance spectroscopic imaging as a non‐destructive, in situ, method to investigate variation in epicuticular wax distribution at 25 µm spatial resolution is presented. The authors demonstrate in vivo imaging of alterations in epicuticular waxes during leaf development and in situ imaging during plant disease or exposure to environmental stressors. It is envisaged that this new analytical capability will enable in vivo studies of plants to provide insights into how the physiology of plants and crops respond to environmental stresses such as disease, soil contamination, drought, soil acidity, and climate change.
Publisher: American Chemical Society (ACS)
Date: 18-12-2019
DOI: 10.1021/ACSCHEMNEURO.9B00257
Abstract: There is increased recognition of the effects of diffuse traumatic brain injury (dTBI), which can initiate yet unknown biochemical cascades, resulting in delayed secondary brain degeneration and long-term neurological sequela. There is limited availability of therapies that minimize the effect of secondary brain damage on the quality of life of people who have suffered TBI, many of which were otherwise healthy adults. Understanding the cascade of biochemical events initiated in specific brain regions in the acute phase of dTBI and how this spreads into adjacent brain structures may provide the necessary insight into drive development of improved therapies. In this study, we have used direct biochemical imaging techniques (Fourier transform infrared spectroscopic imaging) and elemental mapping (X-ray fluorescence microscopy) to characterize biochemical and elemental alterations that occur in corpus callosum white matter in the acute phase of dTBI. The results provide direct visualization of differential biochemical and ionic changes that occur in the highly vulnerable medial corpus callosum white matter relative to the less vulnerable lateral regions of the corpus callosum. Specifically, the results suggest that altered ionic gradients manifest within mechanically damaged medial corpus callosum, potentially spreading to and inducing lipid alterations to white matter structures in lateral brain regions.
Publisher: American Chemical Society (ACS)
Date: 18-07-2017
DOI: 10.1021/ACS.BIOCHEM.7B00262
Abstract: Alzheimer's disease (AD) is a major international health and economic concern. A key pathological feature of AD is so-called "amyloid-β-plaques", or "Aβ-plaques", which are deposits of aggregated protein, enriched with the Aβ fragment of amyloid precursor protein. Despite their name, the deposits are not pure Aβ and have a heterogeneous, chemically complex composition that can include multiple proteins, lipids, and metal ions (Fe, Cu, or Zn). Despite extensive research, it is still uncertain whether Aβ-plaques are a cause or a consequence of AD pathology. Further characterization of the elemental and biochemical composition within and surrounding Aβ-plaques, and knowledge of how composition varies with disease state or progression, may provide important insight into the relationship between Aβ-plaques and AD pathology. With this aim in mind, herein we demonstrate a multimodal spectroscopic imaging workflow to better characterize the complex composition of Aβ-plaques. Our approach incorporates several spectroscopic imaging techniques, such as Fourier transform infrared spectroscopic imaging (FTIR), Raman microscopy, and X-ray fluorescence microscopy (XFM). While FTIR, Raman, and XFM have been used previously, mostly in isolation, to study Aβ-plaques, application of all three techniques, in combination with histology and fluorescence microscopy, has not been reported previously. We demonstrate that a multimodal workflow, incorporating all three methods on adjacent or serial tissue sections, can reveal substantial complementary information about the biochemical and elemental composition of Aβ-plaques. Information revealed by the method includes the relative content and distribution of aggregated protein, total lipid, lipid esters, cholesterol, and metals (Fe, Cu, or Zn).
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2VA00313A
Abstract: Reflectance-FTIR spectroscopy provides opportunities for faster, more automated, and cheaper detection of microplastics in the environment.
Publisher: Elsevier BV
Date: 2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8AN01543K
Abstract: Coupling synchrotron IR beam to an ATR element enhances spatial resolution suited for high-resolution single cell analysis in biology, medicine and environmental science.
Publisher: Elsevier BV
Date: 11-2018
Publisher: Frontiers Media SA
Date: 28-08-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1AN01951A
Abstract: Transfer and persistence of metals in latent fingermarks derived from objects of forensic interest explored using synchrotron sourced X-ray fluorescence microscopy.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1AN00136A
Abstract: SR-ATR-FTIR has been used to improve the diffraction limited spatial resolution of infrared micro-spectroscopy, enabling this study to reveal the sub-cellular location of protein aggregates and lipophilic inclusions in brain cells, and bacteria.
Publisher: Springer Science and Business Media LLC
Date: 17-08-2022
DOI: 10.1007/S41061-022-00400-X
Abstract: Fluorescence microscopy is a key tool in the biological sciences, which finds use as a routine laboratory technique (e.g., epifluorescence microscope) or more advanced confocal, two-photon, and super-resolution applications. Through continued developments in microscopy, and other analytical methods, the importance of lipids as constituents of subcellular organelles, signalling or regulating molecules continues to emerge. The increasing recognition of the importance of lipids to fundamental cell biology (in health and disease) has prompted the development of protocols and techniques to image the distribution of lipids in cells and tissues. A erse suite of spectroscopic and microscopy tools are continuously being developed and explored to add to the “toolbox” to study lipid biology. A relatively recent breakthrough in this field has been the development and subsequent application of metal-based luminescent complexes for imaging lipids in biological systems. These metal-based compounds appear to offer advantages with respect to their tunability of the photophysical properties, in addition to capabilities centred around selectively targeting specific lipid structures or classes of lipids. The presence of the metal centre also opens the path to alternative imaging modalities that might not be applicable to traditional organic fluorophores. This review examines the current progress and developments in metal-based luminescent complexes to study lipids, in addition to exploring potential new avenues and challenges for the field to take.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2AN01271E
Abstract: Ex vivo FTIR imaging reveals lipid distributions (red) alongside other spectroscopic markers in brain tissue, which can be used to provide greater biochemical insight when combined with in vivo MRI data sets collected from the same brain.
Publisher: Elsevier BV
Date: 12-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9SC01432B
Abstract: This article demonstrates a fully synthetic strategy enabling CRISPR-mediated activation of tumour suppressor genes in vivo to reduce tumour burden.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0AN00269K
Abstract: Understanding biochemical mechanisms and changes associated with disease conditions and, therefore, development of improved clinical treatments, is relying increasingly on various biochemical mapping and imaging techniques on tissue sections. However, it is essential to be able to ascertain whether the s ling used provides the full biochemical information relevant to the disease and is free from artefacts. A multi-modal micro-spectroscopic approach, including FTIR imaging and PIXE elemental mapping, has been used to study the molecular and elemental profile within cryofixed and formalin-fixed murine brain tissue sections. The results provide strong evidence that amino acids, carbohydrates, lipids, phosphates, proteins and ions, such as Cl(-) and K(+), leach from tissue sections into the aqueous fixative medium during formalin fixation of the sections. Large changes in the concentrations and distributions of most of these components are also observed by washing in PBS even for short periods. The most likely source of the chemical species lost during fixation is the extra-cellular and intra-cellular fluid of tissues. The results highlight that, at best, analysis of formalin-fixed tissues gives only part of the complete biochemical "picture" of a tissue s le. Further, this investigation has highlighted that significant lipid peroxidation/oxidation may occur during formalin fixation and that the use of standard histological fixation reagents can result in significant and differential metal contamination of different regions of tissue sections. While a consistent and reproducible fixation method may be suitable for diagnostic purposes, the findings of this study strongly question the use of formalin fixation prior to spectroscopic studies of the molecular and elemental composition of biological s les, if the primary purpose is mechanistic studies of disease pathogenesis.
Publisher: Frontiers Media SA
Date: 22-01-2020
Publisher: American Chemical Society (ACS)
Date: 14-06-2018
DOI: 10.1021/ACSCHEMNEURO.8B00193
Abstract: Western society is facing a health epidemic due to the increasing incidence of dementia in aging populations, and there are still few effective diagnostic methods, minimal treatment options, and no cure. Aging is the greatest risk factor for memory loss that occurs during the natural aging process, as well as being the greatest risk factor for neurodegenerative disease such as Alzheimer's disease. Greater understanding of the biochemical pathways that drive a healthy aging brain toward dementia (pathological aging or Alzheimer's disease), is required to accelerate the development of improved diagnostics and therapies. Unfortunately, many animal models of dementia model chronic amyloid precursor protein overexpression, which although highly relevant to mechanisms of amyloidosis and familial Alzheimer's disease, does not model well dementia during the natural aging process. A promising animal model reported to model mechanisms of accelerated natural aging and memory impairments, is the senescence accelerated murine prone strain 8 (SAMP8), which has been adopted by many research group to study the biochemical transitions that occur during brain aging. A limitation to traditional methods of biochemical characterization is that many important biochemical and elemental markers (lipid saturation, lactate, transition metals) cannot be imaged at meso- or microspatial resolution. Therefore, in this investigation, we report the first multimodal biospectroscopic characterization of the SAMP8 model, and have identified important biochemical and elemental alterations, and colocalizations, between 4 month old SAMP8 mice and the relevant control (SAMR1) mice. Specifically, we demonstrate direct evidence of Zn deficiency within specific subregions of the hippoc al CA3 sector, which colocalize with decreased lipid unsaturation. Our findings also revealed colocalization of decreased lipid unsaturation and increased lactate in the corpus callosum white matter, adjacent to the hippoc us. Such findings may have important implication for future research aimed at elucidating specific biochemical pathways for therapeutic intervention.
Publisher: Oxford University Press (OUP)
Date: 2019
DOI: 10.1039/C8MT00230D
Abstract: X-ray fluorescence microscopy reveals unique elemental signatures within sub-populations of hippoc al pyramidal neurons.
Publisher: Public Library of Science (PLoS)
Date: 28-06-2016
Publisher: Elsevier BV
Date: 12-2018
Publisher: Springer Science and Business Media LLC
Date: 29-04-2021
DOI: 10.1038/S41598-021-88854-9
Abstract: Repeated sub-concussive impact (e.g . soccer ball heading), a significantly lighter form of mild traumatic brain injury, is increasingly suggested to cumulatively alter brain structure and compromise neurobehavioural function in the long-term. However, the underlying mechanisms whereby repeated long-term sub-concussion induces cerebral structural and neurobehavioural changes are currently unknown. Here, we utilised an established rat model to investigate the effects of repeated sub-concussion on size of lateral ventricles, cerebrovascular blood–brain barrier (BBB) integrity, neuroinflammation, oxidative stress, and biochemical distribution. Following repeated sub-concussion 3 days per week for 2 weeks, the rats showed significantly enlarged lateral ventricles compared with the rats receiving sham-only procedure. The sub-concussive rats also presented significant BBB dysfunction in the cerebral cortex and hippoc al formation, whilst neuromotor function assessed by beamwalk and rotarod tests were comparable to the sham rats. Immunofluorescent and spectroscopic microscopy analyses revealed no significant changes in neuroinflammation, oxidative stress, lipid distribution or protein aggregation, within the hippoc us and cortex. These data collectively indicate that repeated sub-concussion for 2 weeks induce significant ventriculomegaly and BBB disruption, preceding neuromotor deficits.
Publisher: Cambridge University Press (CUP)
Date: 23-10-2019
DOI: 10.1017/S000711451900268X
Abstract: Studies show that vitamin D (vit-D) (25(OH)D), the bioactive metabolite (1,25(OH) 2 D 3 ) and vit-D receptors (vit-D receptor protein disulphide isomerase, family A member 3) are expressed throughout the brain, particularly in regions pivotal to learning and memory. This has led to the paradigm that avoiding vit-D deficiency is important to preserve cognitive function. However, presently, it is not clear if the common clinical measure of serum 25(OH)D serves as a robust surrogate marker for central nervous system (CNS) homeostasis or function. Indeed, recent studies report CNS biosynthesis of endogenous 25(OH)D, the CNS expression of the CYP group of enzymes which catalyse conversion to 1,25(OH) 2 D 3 and thereafter, deactivation. Moreover, in the periphery, there is significant ethnic/genetic heterogeneity in vit-D conversion to 1,25(OH) 2 D 3 and there is a paucity of studies which have actually investigated vit-D kinetics across the cerebrovasculature. Compared with peripheral organs, the CNS also has differential expression of receptors that trigger cellular response to 1,25(OH) 2 D 3 metabolites. To holistically consider the putative association of peripheral (blood) abundance of 25(OH)D on cognitive function, herein, we have reviewed population and genetic studies, pre-clinical and clinical intervention studies and moreover have considered potential confounders of vit-D analysis.
Publisher: SPIE
Date: 29-04-2017
DOI: 10.1117/12.2272365
Publisher: American Chemical Society (ACS)
Date: 03-2019
DOI: 10.1021/ACSCHEMNEURO.9B00039
Abstract: Non-insulin-dependent diabetes mellitus (NIDDM) is reported to increase the risk of cognitive impairment and dementia. However, the underlying mechanisms are not fully understood. While the brain homeostasis of metals and lipids is pivotal to maintaining energy metabolism and redox homeostasis for healthy brain function, no studies have reported hippoc al metal and biochemical changes in NIDDM. Therefore, we here utilized direct spectroscopic imaging to reveal the elemental distribution within the hippoc al subregions of an established murine model of NIDDM, db/db mice. In 26-week-old insulin resistant db/db mice, X-ray fluorescence microscopy revealed that the Cu content within the dentate gyrus and CA3 was significantly greater than that of the age-matched nondiabetic control mice. In addition, Fourier transform infrared (FTIR) spectroscopy analysis indicated a significant increase in the abundance of lactate within the corpus callosum (CC), dentate gyrus, CA1, and CA3 regions of diabetic db/db mice compared to that of the control, indicating altered energy metabolism. FTIR analysis also showed a significant decrease in the level of lipid methylene and ester within the CC of db/db mice. Furthermore, immunomicroscopy analyses demonstrated the increase in the level of glial fibrillary acidic protein expression and peri-vascular extravasation of IgG, indicating astrogliosis and blood-brain barrier dysfunction, respectively. These data suggest that astrogliosis-induced alterations in the supply of Cu, lipids, and energy substrates may be involved in the mechanisms of NIDDM-associated cognitive decline.
Publisher: American Chemical Society (ACS)
Date: 21-06-2021
Publisher: Portland Press Ltd.
Date: 19-03-2021
DOI: 10.1042/BCJ20200653
Abstract: Hepatocytes are essential for maintaining the homeostasis of iron and lipid metabolism in mammals. Dysregulation of either iron or lipids has been linked with serious health consequences, including non-alcoholic fatty liver disease (NAFLD). Considered the hepatic manifestation of metabolic syndrome, NAFLD is characterised by dysregulated lipid metabolism leading to a lipid storage phenotype. Mild to moderate increases in hepatic iron have been observed in ∼30% of in iduals with NAFLD however, direct observation of the mechanism behind this increase has remained elusive. To address this issue, we sought to determine the metabolic consequences of iron loading on cellular metabolism using live cell, time-lapse Fourier transform infrared (FTIR) microscopy utilising a synchrotron radiation source to track biochemical changes. The use of synchrotron FTIR is non-destructive and label-free, and allowed observation of spatially resolved, sub-cellular biochemical changes over a period of 8 h. Using this approach, we have demonstrated that iron loading in AML12 cells induced perturbation of lipid metabolism congruent with steatosis development. Iron-loaded cells had approximately three times higher relative ester carbonyl concentration compared with controls, indicating an accumulation of triglycerides. The methylene/methyl ratio qualitatively suggests the acyl chain length of fatty acids in iron-loaded cells increased over the 8 h period of monitoring compared with a reduction observed in the control cells. Our findings provide direct evidence that mild to moderate iron loading in hepatocytes drives de novo lipid synthesis, consistent with a role for iron in the initial hepatic lipid accumulation that leads to the development of hepatic steatosis.
Publisher: Oxford University Press (OUP)
Date: 18-05-2023
DOI: 10.1093/JXB/ERAD183
Abstract: Pathogen attacks elicit dynamic and widespread molecular responses in plants. While our understanding of plant responses has advanced considerably, little is known of the molecular responses in the asymptomatic ‘green’ regions adjoining lesions. Here, we explore gene expression data and high-resolution elemental imaging to report the spatiotemporal changes in the asymptomatic green region of susceptible and moderately resistant wheat cultivars infected with a necrotrophic fungal pathogen, Pyrenophora tritici-repentis. We show, with improved spatiotemporal resolution, that calcium oscillations are modified in the susceptible cultivar, resulting in ‘frozen’ host defence signals at the mature disease stage, and silencing of the host’s recognition and defence mechanisms that would otherwise protect it from further attacks. In contrast, calcium accumulation and a heightened defence response were observed in the moderately resistant cultivar in the later stage of disease development. Furthermore, in the susceptible interaction, the asymptomatic green region was unable to recover after disease disruption. Our targeted s ling technique also enabled detection of eight previously predicted proteinaceous effectors in addition to the known ToxA effector. Collectively, our results highlight the benefits of spatially resolved molecular analysis and nutrient mapping to provide high-resolution spatiotemporal snapshots of host–pathogen interactions, paving the way for disentangling complex disease interactions in plants.
Publisher: Oxford University Press (OUP)
Date: 2022
Abstract: Metal ions (Fe, Cu, and Zn) are essential to a healthy brain function, with the amount, localisation, and chemical form often tightly controlled. Evidence points towards loss of metal ion homeostasis within the ageing brain in particular brain Fe accumulation appears to be a hallmark of ageing, which may place the brain at a greater risk of neurodegenerative disease. Unfortunately, the cause or consequence of altered brain metal ion homeostasis during ageing remains unknown, and there is a lack of data comparing brain metal ion homeostasis with other events of the ageing process (e.g. brain metabolism, brain inflammation). This study has utilised a multi-modal approach that incorporated: X-ray fluorescence microscopy for elemental mapping of metal ion homeostasis, Perl's Fe histochemistry, FTIR spectroscopic biochemical imaging of lactate and protein aggregates, and immuno-fluorescence analysis of markers of brain inflammation and Fe storage proteins (heavy-chain ferritin, light-chain ferritin, and mitochondrial ferritin). Interestingly, while age-related Fe accumulation was observed in corpus callosum white matter of murine (C56BL/6J) brain tissue (concomitant with elevated levels of markers of brain inflammation and altered metabolism), Fe content was not altered within the hippoc us (a decrease in total Zn within the mossy fibres was observed). Ultimately, the results of this study demonstrate an important association between elevated brain Fe and brain inflammation during natural ageing. This study also highlights that future research is required to image different chemical forms of Fe with respect to changes in brain metabolism and inflammation, as well as localising these changes to specific cell types.
Publisher: IM Publications Open LLP
Date: 11-04-2022
DOI: 10.1255/SEW.2022.A8
Publisher: Elsevier BV
Date: 02-2010
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1AN02293H
Abstract: Using synchrotron sourced ATR-FTIR microspectroscopy and THz/Far-IR gas phase spectroscopy to monitor the chemical changes in fingermark residues in the immediate hours following deposition.
Publisher: MDPI AG
Date: 20-12-2016
DOI: 10.3390/NU8120828
Publisher: Springer Science and Business Media LLC
Date: 26-07-2021
DOI: 10.1038/S41598-021-94718-Z
Abstract: Kafirin, the hydrophobic prolamin storage protein in sorghum grain is enriched when the grain is used for bioethanol production to give dried distillers grain with solubles (DGGS) as a by-product. There is great interest in DDGS kafirin as a new source for biomaterials. There is however a lack of fundamental understanding of how the physicochemical properties of DDGS kafirin having been exposed to the high temperature conditions during ethanol production, compare to kafirin made directly from the grain. An understanding of these properties is required to catalyse the utilisation of DDGS kafirin for biomaterial applications. The aim of this study was to extract kafirin directly from sorghum grain and from DDGS derived from the same grain and, then perform a comparative investigation of the physicochemical properties of these kafirins in terms of: polypeptide profile by sodium-dodecyl sulphate polyacrylamide gel electrophoresis secondary structure by Fourier transform infra-red spectroscopy and x-ray diffraction, self-assembly behaviour by small-angle x-ray scattering, surface morphology by scanning electron microscopy and surface chemical properties by energy dispersive x-ray spectroscopy. DDGS kafirin was found to have very similar polypeptide profile as grain kafirin but contained altered secondary structure with increased levels of β-sheets. The structure morphology showed surface fractals and surface elemental composition suggesting enhanced reactivity with possibility to endow interfacial wettability. These properties of DDGS kafirin may provide it with unique functionality and thus open up opportunities for it to be used as a novel food grade biomaterial.
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Start Date: 03-2020
End Date: 03-2024
Amount: $739,302.00
Funder: Australian Research Council
View Funded ActivityStart Date: 10-2022
End Date: 09-2025
Amount: $420,000.00
Funder: Australian Research Council
View Funded Activity