title: Disrupted daily light-dark cycle induces the expression of hepatic gluconeogenic regulatory genes and hyperglycemia with glucose intolerance in mice.
abstract: We elucidated associations between metabolic disorders and the environmental light-dark (LD) cycle that entrains the circadian clock located in the suprachiasmatic nucleus of mammals. Mice were fed with a high-fat/high-sucrose diet for eight weeks under a normal 12h light-12h dark cycle (LD 12:12) or an ultradian 3h light-3h dark cycle (LD 3:3) that might perturb the central clock. The circadian behavioral rhythms were gradually disturbed under LD 3:3. Hyperglycemia with glucose intolerance and increases in diabetic markers, glycated albumin and hemoglobin A1c, were significantly induced without affecting body weight gain and food consumption in LD 3:3. Expression levels of hepatic gluconeogenic regulatory genes such as Pck1, G6pc, Hnf4a, and Foxo1/3/4 genes were increased under LD 3:3. Hypercholesterolemia with hepatic cholesterol accumulation was also induced in LD 3:3. Ultradian LD 3:3 cycles did not affect the adipose inflammation that is considered a major player in obesity-associated metabolic disorders. Our findings provide a link between metabolic disorders and environmental photoperiodic cycles in genetically normal animals.
authors: Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan. k-ooishi@aist.go.jp
authors: Katsutaka
authors: K
authors: Oishi
authors: Nanako
authors: N
authors: Itoh
mesh_terms: D000818:Animals; D001786:Blood Glucose; D002784:Cholesterol / Q000378:metabolism; D057906:Circadian Clocks; D005786:Gene Expression Regulation; D005809:Genes, Regulator / Q000235:genetics*; D005943:Gluconeogenesis / Q000235:genetics*; D018149:Glucose Intolerance / Q000235:genetics*; D006943:Hyperglycemia / Q000235:genetics*; D007328:Insulin / Q000097:blood; D008099:Liver / Q000378:metabolism*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D017440:Photoperiod
chemical_list: D001786:Blood Glucose; D007328:Insulin; D002784:Cholesterol