Woodie Lauren N, Alberto Ahren J, Krusen Brianna M, Melink Lily C, Lazar Mitchell A
Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104.
Proc Natl Acad Sci U S A. 2024 Dec 17;121(51):e2417678121. doi: 10.1073/pnas.2417678121. Epub 2024 Dec 12.
Nearly every cell of the body contains a circadian clock mechanism that is synchronized with the light-entrained clock in the suprachiasmatic nucleus (SCN). Desynchrony between the SCN and the external environment leads to metabolic dysfunction in shift workers. Similarly, mice with markedly shortened endogenous period due to the deletion of circadian REV-ERBα/β nuclear receptors in the SCN (SCN DKO) exhibit increased sensitivity to diet-induced obesity (DIO) on a 24 h light:dark cycle while mice with REV-ERBs deleted in hepatocytes (HepDKO) display exacerbated hepatosteatosis in response to a high-fat diet. Here, we show that inducing deletion of hepatocyte REV-ERBs in SCN DKO mice (Hep-SCN DDKO) rescued the exacerbated DIO and hepatic triglyceride accumulation, without affecting the shortened behavioral period. These findings suggest that metabolic disturbances due to environmental desynchrony with the central clock are due to effects on peripheral clocks which can be mitigated by matching peripheral and central clock periods even in a desynchronous environment. Thus, maintaining synchrony within an organism, rather than between endogenous and exogenous clocks, may be a viable target for the treatment of metabolic disorders associated with circadian disruption.
机体几乎每个细胞都含有一个昼夜节律时钟机制,该机制与视交叉上核(SCN)中受光调节的时钟同步。SCN与外部环境之间的不同步会导致轮班工作者出现代谢功能障碍。同样,由于SCN中昼夜节律REV-ERBα/β核受体缺失而导致内源性周期明显缩短的小鼠(SCN DKO),在24小时明暗周期下对饮食诱导的肥胖(DIO)敏感性增加,而肝细胞中REV-ERBs缺失的小鼠(HepDKO)在高脂饮食下会出现更严重的肝脂肪变性。在此,我们表明,在SCN DKO小鼠(Hep-SCN DDKO)中诱导肝细胞REV-ERBs缺失可挽救加剧的DIO和肝脏甘油三酯积累,而不会影响缩短的行为周期。这些发现表明,与中央时钟的环境不同步引起的代谢紊乱是由于对外周时钟的影响,即使在不同步的环境中,通过匹配外周和中央时钟周期也可以减轻这种影响。因此,维持生物体内的同步性,而非内源性和外源性时钟之间的同步性,可能是治疗与昼夜节律紊乱相关的代谢紊乱的一个可行靶点。