title: Circadian clocks and feeding time regulate the oscillations and levels of hepatic triglycerides.
abstract: Circadian clocks play a major role in orchestrating daily physiology, and their disruption can evoke metabolic diseases such as fatty liver and obesity. To study the role of circadian clocks in lipid homeostasis, we performed an extensive lipidomic analysis of liver tissues from wild-type and clock-disrupted mice either fed ad libitum or night fed. To our surprise, a similar fraction of lipids (∼17%) oscillated in both mouse strains, most notably triglycerides, but with completely different phases. Moreover, several master lipid regulators (e.g., PPARα) and enzymes involved in triglyceride metabolism retained their circadian expression in clock-disrupted mice. Nighttime restricted feeding shifted the phase of triglyceride accumulation and resulted in ∼50% decrease in hepatic triglyceride levels in wild-type mice. Our findings suggest that circadian clocks and feeding time dictate the phase and levels of hepatic triglyceride accumulation; however, oscillations in triglycerides can persist in the absence of a functional clock.
authors: Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Yaarit
authors: Y
authors: Adamovich
authors: Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Liat
authors: L
authors: Rousso-Noori
authors: Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Ziv
authors: Z
authors: Zwighaft
authors: Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Adi
authors: A
authors: Neufeld-Cohen
authors: Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Marina
authors: M
authors: Golik
authors: Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Judith
authors: J
authors: Kraut-Cohen
authors: Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors: Miao
authors: M
authors: Wang
authors: Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
authors: Xianlin
authors: X
authors: Han
authors: Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel. Electronic address: gad.asher@weizmann.ac.il.
authors: Gad
authors: G
authors: Asher
mesh_terms: D000818:Animals; D057906:Circadian Clocks / Q000502:physiology*; D008099:Liver / Q000378:metabolism*; D008297:Male; D051379:Mice; D008954:Models, Biological; D060888:Real-Time Polymerase Chain Reaction; D014280:Triglycerides / Q000378:metabolism*
chemical_list: D014280:Triglycerides