Effect of H2S on the circadian rhythm of mouse hepatocytes

We established a hepatocyte model that showed a circadian rhythm by serum shock method. And detected that the expression level and the peak of circadian clock genes decreased gradually and H2S could maintain the expression and amplitude of circadian clock genes such as Clock, Per2, Bmal1 and Rev-erbαwithin a certain period time. Accordingly the expression level of sirt1 in H2S group was significantly higher than that in the control group.Exogenous reductant H2S maintain the circadian rhythm of clock gene in isolated liver cells. We speculated that H2S has changed NAD+/NADH content ratio in hepatocytes and enhanced the activity of SIRT1 protein directly or indirectly, so as to maintain the rhythm of expression of circadian clock genes, they play a role in the prevention and treatment of lipid metabolism-related disease caused by the biological clock disorders.To adapt the changes of environment, all species on the earth have a life cycle synchronized approximately with the circadian rhythm of the planet. In mammals, the central circadian clock is located in hypothalamic supraoptic nucleus (SCN) [1] with a sensitivity of the outside light signal. Peripheral circadian clock is regulated by the central circadian clock. The negative feedback loop composed of circadian clock genes and their expression products oscillate autonomously. Circadian rhythm of life on earth is realized in this way [2]. Main circadian clock genes includes Clock, Bmal1, Per2, Rev-erbα, Cry1 etc. [3,4] Disorder of circadian rhythms can contribute to disease. Conversely, metabolic signals also feed back into the circadian system, modulating circadian gene expression and behavior [5]. Many peripheral tissues have a rhythmic expression of circadian genes as well as SCN. Especially products of circadian genes in fat, liver, heart, pancreatic β-cell are all directly or indirectly involved in energy metabolism [6,7]. Emerging evidence suggests that there are food-induced oscillators independent of the SC