Effect of intermittent fasting on circadian rhythms in mice depends on feeding time.
Calorie restriction (CR) resets circadian rhythms and extends life span. Intermittent fasting (IF) also extends life span, but its affect on circadian rhythms has not been studied. To study the effect of IF alongside CR, we imposed IF in FVB/N mice or IF combined with CR using the transgenic FVB/N alphaMUPA mice that, when fed ad libitum, exhibit spontaneously reduced eating and extended life span. Our results show that when food was introduced during the light period, body temperature peak was not disrupted. In contrast, IF caused almost arrhythmicity in clock gene expression in the liver and advanced mPer2 and mClock expression. However, IF restored the amplitudes of clock gene expression under disruptive light condition regardless whether the animals were calorically restricted or not. Unlike daytime feeding, nighttime feeding yielded rhythms similar to those generated during ad libitum feeding. Taken together, our results show that IF can affect circadian rhythms differently depending on the timing of food availability, and suggest that this regimen induces a metabolic state that affects the suprachiasmatic nuclei (SCN) clock.
Froy
Oren
O
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. froy@agri.huji.ac.il
Chapnik
Nava
N
Miskin
Ruth
R
D056930:ARNTL Transcription Factors; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics; D001522:Behavior, Animal; D001831:Body Temperature; D056926:CLOCK Proteins; D031204:Caloric Restriction; D018797:Cell Cycle Proteins / Q000235:genetics; D002940:Circadian Rhythm / Q000235:genetics; D056931:Cryptochromes; D004435:Eating; D005215:Fasting; D005247:Feeding Behavior; D005420:Flavoproteins / Q000235:genetics; D005786:Gene Expression Regulation; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics; D008099:Liver / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009687:Nuclear Proteins / Q000235:genetics; D056950:Period Circadian Proteins; D017440:Photoperiod; D012313:RNA / Q000378:metabolism; D013997:Time Factors; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics / Q000378:metabolism
D056930:ARNTL Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D018797:Cell Cycle Proteins; D056931:Cryptochromes; D005420:Flavoproteins; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D056950:Period Circadian Proteins; D012313:RNA; D015534:Trans-Activators; D014157:Transcription Factors; D014568:Urokinase-Type Plasminogen Activator; C538961:Bmal1 protein, mouse; C539023:Per1 protein, mouse; C513312:Per2 protein, mouse; C538944:Clock protein, mouse