Project description:Mice were fed a normal chow diet or a tryptophan depleted diet for two weeks under normal 12-hr light/dark cycles (LD) or in constant darkness (DD). Mice were sacrificed every 4th hour over the 24-hr circadian cycle. The suprachiasmatic nucleus (SCN) was harvested and RNA was isolated using a standard TRIZOL protocol. The data suggest that dietary tryptophan is an important component of the diet regulating circadian homeostsis.
Project description:Mice were fed a normal chow diet or a tryptophan depleted diet for two weeks under normal 12-hr light/dark cycles (LD) or in constant darkness (DD). Mice were sacrificed every 4th hour over the 24-hr circadian cycle. The liver was harvested and RNA was isolated using a standard TRIZOL protocol. The data suggest that dietary tryptophan is an important component of the diet regulating circadian homeostsis.
Project description:Observational, non randomized study aimed at measuring the circadian rhythms in the urinary concentrations of physiological modified nucleosides in 30 patients with metastatic colorectal cancer and in 30 age and sex-matched healthy subjects.
Project description:Ketone bodies, intermediates in energy metabolism and signaling, have attracted significant attention due to their role in health and disease. We performed around the clock study on ketone bodies and ketogenesis with mice on different diets. We found that caloric restriction, a dietary intervention that improves metabolism and longevity, induced high amplitude circadian rhythms in blood βOHB. The blood βOHB rhythms resulted from rhythmic ketogenesis in the liver controlled by the interaction between the circadian clock and PPAR transcriptional networks. This interaction results in transcriptional reprogramming of in beta-oxidation and ketogenesis enzymes. The reprogramming is impaired in circadian clock mutant mice. The circadian clock gated ketogenesis contributes to the diet impact on health and longevity.
Project description:To investigate the intestinal ileum response to dietary tryptophan deficiency and the contribution of the intestinal microbiome in regulating these responses
Project description:Chromatin organization plays a crucial role in gene regulation by controlling the accessibility of DNA to transcription machinery. While significant progress has been made in understanding the regulatory role of clock proteins in circadian rhythms, how chromatin organization affects circadian rhythms remains poorly understood. Here, we employed ATAC-seq (Assay for Transposase-Accessible Chromatin with Sequencing) on FAC-sorted Drosophila clock neurons to assess genome-wide chromatin accessibility at dawn and dusk over the circadian cycle. We observed significant oscillations in chromatin accessibility at promoter and enhancer regions of hundreds of genes, with enhanced accessibility either at dusk or dawn, which correlated with their peak transcriptional activity. Notably, genes with enhanced accessibility at dusk were enriched with E-box motifs, while those more accessible at dawn were enriched with VRI/PDP1-box motifs, indicating that they are regulated by the core circadian feedback loops, PER/CLK and VRI/PDP1, respectively. Further, we observed a complete loss of chromatin accessibility rhythms in per01 null mutants, with chromatin consistently accessible at both dawn and dusk, underscoring the critical role of Period protein in driving chromatin compaction during the repression phase at dawn. Together, this study demonstrates the significant role of chromatin organization in circadian regulation, revealing how the interplay between clock proteins and chromatin structure orchestrates the precise timing of biological processes throughout the day. This work further implies that variations in chromatin accessibility might play a central role in the generation of diverse circadian gene expression patterns in clock neurons.