A Balanced Diet Is Necessary for Proper Entrainment Signals of the Mouse Liver Clock

Abstract

BackgroundThe peripheral circadian clock in mice is entrained not only by light-dark cycles but also by daily restricted feeding schedules. Behavioral and cell culture experiments suggest an increase in glucose level as a factor in such feeding-induced entrainment. For application of feeding-induced entrainment in humans, nutrient content and dietary variations should be considered.Principal FindingTo elucidate the food composition necessary for dietary entrainment, we examined whether complete or partial substitution of dietary nutrients affected phase shifts in liver clocks of mice. Compared with fasting mice or ad libitum fed mice, the liver bioluminescence rhythm advanced by 3–4 h on the middle day in Per2::luciferase knock-in mice that were administered a standard mouse diet, i.e. AIN-93M formula [0.6–0.85 g/10 g mouse BW] (composition: 14% casein, 47% cornstarch, 15% gelatinized cornstarch, 10% sugar, 4% soybean oil, and 10% other [fiber, vitamins, minerals, etc.]), for 2 days. When each nutrient was tested alone (100% nutrient), an insignificant weak phase advance was found to be induced by cornstarch and soybean oil, but almost no phase advance was induced by gelatinized cornstarch, high-amylose cornstarch, glucose, sucrose, or casein. A combination of glucose and casein without oil, vitamin, or fiber caused a significant phase advance. When cornstarch in AIN-93M was substituted with glucose, sucrose, fructose, polydextrose, high-amylose cornstarch, or gelatinized cornstarch, the amplitude of phase advance paralleled the increase in blood glucose concentration.ConclusionsOur results strongly suggest the following: (1) balanced diets containing carbohydrates/sugars and proteins are good for restricted feeding-induced entrainment of the peripheral circadian clock and (2) a balanced diet that increases blood glucose, but not by sugar alone, is suitable for entrainment. These findings may assist in the development of dietary recommendations for on-board meals served to air travelers and shift workers to reduce jet lag-like symptoms.

Diurnal expression ofDnmt3bmRNA in mouse liver is regulated by feeding and hepatic clockwork

“…The hepatic circadian clock has been found to be entrained by central signals [36][37][38] and peripheral signals of ingested nutrients. [39][40][41][42] In view of the similarities between the expression patterns of Bmal1 and Dnmt3b observed in our developmental experiment and SF Figure 3. Effect of scheduled feeding on Dnmt3b and Bmal1 mRNa expression patterns in the liver.…”

Combination of starvation interval and food volume determines the phase of liver circadian rhythm in Per2::Luc knock-in mice under two meals per day feeding

“…In a previous study, the starvation period was slowly shortened by 12,6, and 4 h to avoid an acute loss of body weight (see Ref. 24 for review).…”

The Uterus Sustains Stable Biological Clock during Pregnancy

“…Photon counts from each culture were detrended with a 2-h running average as described previously (Yamazaki et al 2000) with modifications using exmax software (gift from Mr. Tuyoshi Yaita and Dr. Shigenobu Shibata, Waseda University, Tokyo, Japan) (Hayasaka et al 2007;Ohta et al 2008;Hirao et al 2009). The period of Per1-luc activity (recorded from 12 to 84 h in vitro) was assessed for each SCN culture and calculated by averaging the period between the first and second peaks and the period between the second and third peaks as previously described (Yamazaki et al 2000;Ohta et al 2005).…”