GSE201207
Defining the age-dependent and tissue-specific circadian transcriptome in male mice
Cellular circadian clocks direct a daily transcriptional program that supports homeostasis. Emerging evidence supports age-associated changes in circadian functions. To define age-dependent changes at the systems level, we profiled the circadian transcriptome in the hypothalamus, lung, heart, kidney, skeletal muscle, and adrenal gland in 3 age groups. We found age-dependent and tissue-specific clock output changes. Aging reduced the number of rhythmically expressed genes (REGs), indicative of weakened circadian control. Many genes gained rhythmicity in old tissues, reflecting an adaptive response. REGs were enriched for the hallmarks of aging, adding a new dimension to understanding aging. Differential gene expression analysis found that there were temporally distinct clusters of genes in tissue-specific manner. This novel analysis extends the landscape of the understanding of aging. Increased daily gene expression variability is a common feature of aged tissues. Our data highlight the impact of aging on circadian function and temporal changes in gene expression. Overall design: Hypothalamus, lung, kidney, skeletal muscle, heart, and adrenal gland tissues from Young (6mo), Aged (18mo), and Old (27mo) male mice were collected every 4h for 48h to characterize the circadian transcriptome changes with age. Two samples per age were collected and pooled for RNAseq analysis.