Age-Induced Differential Changes in the Central and Colonic Human Circadian Oscillators

Effects of resveratrol on in vitro circadian clock gene expression in young and older human adipose-derived progenitor cells

Observational studies in preclinical models demonstrate age-related declines in circadian functions. We hypothesized that age would be associated with declines in function of cell-autonomous circadian clocks in human tissue. Accordingly, we cultured adipose progenitor cells (APCs) from previously collected white-adipose tissue biopsies from abdominal subcutaneous depots of young (Age: 23.4 ± 2.1 yrs) vs. older female participants (Age: 70.6 ± 5.9 yrs). Using an in vitro model, we compared rhythmic gene expression profiles of core clock components, as an indicator of circadian oscillatory function. We observed consistent circadian rhythmicity of core clock components in young and older-APCs. Expression analysis showed increased levels of some components in older-APCs (CLOCK, CRY1, NR1D1) vs. young. We also investigated resveratrol (RSV), a well-known longevity-enhancing effector, for its effects on rhythmic clock gene expression profiles. We found that RSV resulted in gained rhythmicity of some components (CLOCK and CRY), loss of rhythmicity in others (PER2, CRY2), and altered some rhythmic parameters (NR1D1 and NR1D2), consistent in young and older-APCs. The observation of detectable circadian rhythmicity retained in vitro suggests that the oscillatory function of the cell-autonomous core clock in APCs is preserved at this stage of the aging process. RSV impacts core clock gene expression in APCs, implicating its potential as a therapeutic agent for longevity by targeting the core clock.

Oleic acid restores the rhythmicity of the disrupted circadian rhythm found in gastrointestinal explants from patients with morbid obesity

BACKGROUND & AIMS

We investigated whether oleic acid (OA), one of the main components of the Mediterranean diet, participates in the regulation of the intestinal circadian rhythm in patients with morbid obesity.

METHODS

Stomach and jejunum explants from patients with morbid obesity were incubated with oleic acid to analyze the regulation of clock genes.

RESULTS

Stomach explants showed an altered circadian rhythm in CLOCK, BMAL1, REVERBα, CRY1, and CRY2, and an absence in PER1, PER2, PER3 and ghrelin (p > 0.05). OA led to the emergence of rhythmicity in PER1, PER2, PER3 and ghrelin (p < 0.05). Jejunum explants showed an altered circadian rhythm in CLOCK, BMAL1, PER1 and PER3, and an absence in PER2, REVERBα, CRY1, CRY2 and GLP1 (p > 0.05). OA led to the emergence of rhythmicity in PER2, REVERBα, CRY1 and GLP1 (p < 0.05), but not in CRY2 (p > 0.05). OA restored the rhythmicity of acrophase and increased the amplitude for most of the genes studied in stomach and jejunum explants. OA placed PER1, PER2, PER3, REVERBα, CRY1 and CRY2 in antiphase with regard to CLOCK and BMAL1.

CONCLUSIONS

There is an alteration in circadian rhythm in stomach and jejunum explants in morbid obesity. OA restored the rhythmicity of the genes related with circadian rhythm, ghrelin and GLP1, although with slight differences between tissues, which could determine a different behaviour of the explants from jejunum and stomach in obesity.