https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Pathological relationships involving iron and myelin may constitute a shared mechanism linking various rare and common brain diseases https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30189 Hfe−/−xTfr2mut mouse model. This was accompanied by altered expression of a group of myelin-related genes, including a suite of genes causatively linked to the rare disease family ‘neurodegeneration with brain iron accumulation’ (NBIA). Expanded data mining and ontological analyses have now identified additional myelin-related transcriptome changes in response to brain iron loading. Concordance between the mouse transcriptome changes and human myelin-related gene expression networks in normal and NBIA basal ganglia testifies to potential clinical relevance. These analyses implicate, among others, genes linked to various rare central hypomyelinating leukodystrophies and peripheral neuropathies including Pelizaeus-Merzbacher-like disease and Charcot-Marie-Tooth disease as well as genes linked to other rare neurological diseases such as Niemann-Pick disease. The findings may help understand interrelationships of iron and myelin in more common conditions such as hemochromatosis, multiple sclerosis and various psychiatric disorders.]]> Wed 11 Apr 2018 16:58:00 AEST ]]> Evaluation of different normalization and analysis procedures for Illumina gene expression microarray data involving small changes https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:28613 Wed 11 Apr 2018 09:21:51 AEST ]]> Hepatic iron loading in mice increases cholesterol biosynthesis https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:10663 Sat 24 Mar 2018 08:12:41 AEDT ]]> Changes in brain transcripts related to Alzheimer's disease in a model of HFE hemochromatosis are not consistent with increased Alzheimer's disease risk https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:20882 -/- mice, a model of hemochromatosis, relative to age- and gender-matched wildtype controls. Classification by functional pathway analysis revealed transcript changes for various genes important in AD. There were decreases of up to 9-fold in transcripts for amyloid-β protein precursor, tau, apolipoprotein E, presenilin 1, and various other γ-secretase components, as well as Notch signaling pathway molecules. This included decreased transcripts for 'hairy and enhancer of split' Hes1 and Hes5, downstream targets of Notch canonical signaling. The reductions in Hes1 and Hes5 transcripts provide evidence that the changes in levels of transcripts for γ-secretase components and Notch signaling genes have functional consequences. The effects appeared relatively specific for AD in that few genes pertaining to other important neurodegenerative diseases, notably Parkinson's disease and Huntington's disease, or to inflammation, oxidative stress, or apoptosis, showed altered transcript levels. The observed effects on AD-related gene transcripts do not appear to be consistent with increased AD risk in HFE hemochromatosis and might, if anything, be predicted to protect against AD to some extent. As Hfe-/- mice did not have higher brain iron levels than wildtype controls, these studies highlight the need for further research in models of more severe hemochromatosis with brain iron loading.]]> Sat 24 Mar 2018 07:57:56 AEDT ]]> Brain transcriptome perturbations in the Hfe<sup>-/-</sup> mouse model of genetic iron loading https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:21833 HFE gene. There is evidence from both human and animal studies that HFE gene variants may affect brain function and modify risks of brain disease. To investigate how disruption of HFE influences brain transcript levels, we used microarray and real-time reverse transcription polymerase chain reaction to assess the brain transcriptome in Hfe−/− mice relative to wildtype AKR controls (age 10 weeks, n ≥ 4/group). The Hfe−/− mouse brain showed numerous significant changes in transcript levels (p < 0.05) although few of these related to proteins directly involved in iron homeostasis. There were robust changes of at least 2-fold in levels of transcripts for prominent genes relating to transcriptional regulation (FBJ osteosarcoma oncogene Fos, early growth response genes), neurotransmission (glutamate NMDA receptor Grin1, GABA receptor Gabbr1) and synaptic plasticity and memory (calcium/calmodulin-dependent protein kinase IIα Camk2a). As previously reported for dietary iron-supplemented mice, there were altered levels of transcripts for genes linked to neuronal ceroid lipofuscinosis, a disease characterized by excessive lipofuscin deposition. Labile iron is known to enhance lipofuscin generation which may accelerate brain aging. The findings provide evidence that iron loading disorders can considerably perturb levels of transcripts for genes essential for normal brain function and may help explain some of the neurologic signs and symptoms reported in hemochromatosis patients.]]> Sat 24 Mar 2018 07:52:17 AEDT ]]>