title: High-fat diet delays and fasting advances the circadian expression of adiponectin signaling components in mouse liver.
abstract: The circadian clock controls energy homeostasis by regulating circadian expression and/or activity of enzymes involved in metabolism. Disruption of circadian rhythms may lead to obesity and metabolic disorders. We tested whether the biological clock controls adiponectin signaling pathway in the liver and whether fasting and/or high-fat (HF) diet affects this control. Mice were fed low-fat or HF diet and fasted on the last day. The circadian expression of clock genes and components of adiponectin metabolic pathway in the liver was tested at the RNA, protein, or enzyme activity level. In addition, serum levels of glucose, adiponectin, and insulin were measured. Under low-fat diet, adiponectin signaling pathway components exhibited circadian rhythmicity. However, fasting and HF diet altered this circadian expression; fasting resulted in a phase advance, and HF diet caused a phase delay. In addition, adenosine monophosphate-activated protein kinase levels were high during fasting and low during HF diet. Changes in the phase and daily rhythm of clock genes and components of adiponectin signaling pathway as a result of HF diet may lead to obesity and may explain the disruption of other clock-controlled output systems, such as blood pressure and sleep/wake cycle, usually associated with metabolic disorders.
authors.affiliation: Institute of Biochemistry, Food Science, and Nutrition, Faculty of Agricultural, Food, and Environmental Quality, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel.
authors.forename: Maayan
authors.initials: M
authors.lastname: Barnea
authors.forename: Zecharia
authors.initials: Z
authors.lastname: Madar
authors.forename: Oren
authors.initials: O
authors.lastname: Froy
mesh_terms: D000064:Acclimatization; D052242:Adiponectin / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects; D018752:Diet, Fat-Restricted; D004041:Dietary Fats / Q000494:pharmacology*; D005215:Fasting / Q000502:physiology*; D008099:Liver / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
chemical_list: D052242:Adiponectin; D004041:Dietary Fats