Project description:Circadian rhythms are daily physiological and behavioral changes governed by an internal molecular clock, and dysfunctions in circadian rhythms have long been associated with various neurodegenerative diseases. Abnormal sleep-wake cycle often precedes the onset of cognitive and motor symptoms in patients, while the pathological changes may further exacerbate the disturbance in circadian cycle. It is unclear whether dysregulated circadian rhythm is a consequence of, or a contributing factor for, neurodegeneration. In addition, the evidence directly connecting the neurodegeneration-associated proteins to core circadian clock gene expression remains sparse. Here we show that FUS, a RNA-binding protein implicated in the pathogenesis of ALS and frontotemporal dementia, exhibits a bi-directional regulation with circadian rhythm. Our meta-analysis of RNAseq datasets and subsequent biochemical analysis revealed FUS as a gene regulated by circadian oscillation. Furthermore, NR1D1 binds the FUS promoter and regulates the amplitude of FUS oscillation. Meanwhile, FUS is recruited by transcriptional co-repressor PSF, and is found in the same complex as Bmal-Clock to repress Per2 expression. More strikingly, in cells and brain tissues from homozygous knock-in rats, the pathogenic R521C mutant FUS significantly alters the oscillation patterns of core circadian genes even at young age. Therefore, our results have revealed a novel bi-directional mechanism whereby dysregulated circadian clock and FUS expression may exacerbate neurodegeneration via mutual influence.
Project description:To determine whether immortalized cells derived from the rat SCN (SCN2.2) retain intrinsic rhythm-generating properties characteristic of the SCN, oscillatory properties of the SCN2.2 transcriptome were analyzed and compared to those found in the rat SCN in vivo using rat U34A Affymetrix GeneChips. This SuperSeries is composed of the following subset Series:; GSE1654: Circadian Profiling of the Transcriptome in Immortalized Rat SCN Cells (3 biological replicates); GSE1673: Circadian Profiling of the Transcriptome in Immortalized Rat SCN Cells: Comparison to Long-Evans Rat SCN Experiment Overall Design: Refer to individual Series
Project description:Inflammation is a key component of pathological angiogenesis. Here we induce cornea neovascularisation using sutures placed into the cornea, and sutures are removed to induce a regression phase. We used whole transcriptome microarray to monitor gene expression profies of several genes
Project description:Circadian rhythms are generated by an auto-regulatory feedback loop composed of transcriptional activators and repressors. Disruption of circadian rhythms contributes to Type 2 diabetes (T2D) pathogenesis. We elucidated whether altered circadian rhythmicity of clock genes is associated with metabolic dysfunction in T2D. Transcriptional cycling of core clock genes BMAL1, CLOCK, and PER3 was altered in skeletal muscle from individuals with T2D and this was coupled with reduced number and amplitude of cycling genes and disturbed circadian oxygen consumption. Inner-mitochondria associated genes were enriched for rhythmic peaks in NGT, but not T2D, and positively correlated with insulin sensitivity. ChIP-sequencing identified CLOCK and BMAL1 binding to inner-mitochondrial genes associated with insulin sensitivity, implicating regulation by the core clock. Inner-mitochondria disruption altered core-clock gene expression and free-radical production, phenomena that were restored by resveratrol treatment. We identify bi-directional communication between mitochondrial function and rhythmic gene expression, processes which are disturbed in diabetes.
