Genomic and Epigenomic Responses to Chronic Stress Involve miRNA-Mediated Programming
Researchers at the University of Lethbridge and the University of Calgary, Canada have shown by microarray profiling that mild psychological stress (induced by restraint) results in miRNA expression changes.
miRNA microarray expression profiling revealed two miRNAs which fell within with the lowest p-value cutoff (p,0.01). miR-186 was up-regulated (log2 ratio of 0.43) and miR-709 (log2 ratio of 20.66), was down-regulated.
They performed qRT-PCR analysis which confirmed changes in miR- 186 and miR-709 expression after two weeks of stress.
Analysis of miRNA expression in the rat cerebellum after two weeks of stress compared to controls. The microarray Heatmap demonstrates the log2 ratio of miRNA signal difference between control and stress samples. Up-regulated miRNAs are shown in red, while downregulated miRNAs are shown in green. The first three columns on each figure represent the level of expression in control animals, while the three last columns represent the level of corresponding miRNA expression in stress animals.
They hypothesize that restraint stress causes a different response in cerebellum and other brain regions, such as hippocampus and prefrontal cortex and propose the following scheme of stress response in the brain.
These findings suggest a central role of miRNA-regulated gene expression in the stress response and in associated neurological function.
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