Impact of Short-Term Fasting on The Rhythmic Expression of the Core Circadian Clock and Clock-Controlled Genes in Skeletal Muscle of Crucian Carp (Carassius auratus)

Abstract

The peripheral tissue pacemaker is responsive to light and other zeitgebers, especially food availability. Generally, the pacemaker can be reset and entrained independently of the central circadian structures. Studies involving clock-gene expressional patterns in fish peripheral tissues have attracted considerable attention. However, the rhythmic expression of clock genes in skeletal muscle has only scarcely been investigated. The present study was designed to investigate the core clock and functional gene expression rhythms in crucian carp. Meanwhile, the synchronized effect of food restrictions (short-term fasting) on these rhythms in skeletal muscle was carefully examined. In fed crucian carp, three core clock genes (Clock, Bmal1a, and Per1) and five functional genes (Epo, Fas, IGF1R2, Jnk1, and MyoG) showed circadian rhythms. By comparison, four core clock genes (Clock, Bmal1a, Cry3, and Per2) and six functional genes (Epo, GH, IGF2, Mstn, Pnp5a, and Ucp1) showed circadian rhythms in crucian carp muscle after 7-day fasting. In addition, three core clock genes (Clock, Per1, and Per3) and six functional genes (Ampk1a, Lpl, MyoG, Pnp5a, PPARα, and Ucp1) showed circadian rhythms in crucian carp muscle after 15-day fasting. However, all gene rhythmic expression patterns differed from each other. Furthermore, it was found that the circadian genes could be altered by feed deprivation in crucian carp muscle through the rhythms correlation analysis of the circadian genes and functional genes. Hence, food-anticipatory activity of fish could be adjusted through the food delivery restriction under a light–dark cycle. These results provide a potential application in promoting fish growth by adjusting feeding conditions and nutritional state.

Changes in Northern Elephant Seal Skeletal Muscle Following Thirty Days of Fasting and Reduced Activity

“…Skeletal muscle circadian clocks respond to cyclic stimuli including feeding and activity through regulatory genes including CLOCK , ARNTL (aka BMAL1 ), and the period-family circadian regulator PER1 ( Schroder and Esser, 2013 ). Periods of fasting have been shown to alter the expression of key skeletal muscle circadian regulators and the cyclic expression of functional genes in fish skeletal muscle ( Wu et al, 2018 ). In the current study, key circadian rhythm related genes were upregulated during molt including ARNTL and PER1 ( Figure 2D ), and these genes are both tied to circadian regulation of mitochondrial lipid metabolism ( Ezagouri and Asher, 2018 ).…”

The circadian rhythm regulates branched-chain amino acids metabolism in fast muscle of Chinese perch (Siniperca chuatsi) during short-term fasting by Clock-KLF15-Bcat2 pathway

“…Meanwhile, the circadian clock acts as an internal time-keeping mechanism to maintain homoeostasis in response to environment changings. Changes in expression of core clock genes in skeletal muscle after fasting have been reported in fish (33,34) . This study also showed that fasting significantly changed the rhythmic expression of circadian genes, for example, the acrophases of Clock were dramatically changed during 1, 5 and 7 d fasting.…”

“…The daily rhythmicity in relation to the expression of core circadian clock genes, KLF15 and Bcat2 , was assayed with Matlab 7.0. To perform a cosinor analysis, the formula ƒ(t) = M + Acos ( t/pi/12 –ϕ) was used, and the meanings of the letters in the formula refer to previous reports (34) . Significance of cosinor analysis was defined by the noise/signal of amplitude calculated from the ratio se(A)/A (hereafter referred as P -value).…”

“…The effects of fasting on expression of core circadian clocks and BCAAs metabolism in skeletal muscle of fish have been studied [19,33,34], however, the molecular mechanism of circadian rhythm regulating adaptive metabolism of fish skeletal muscle under fasting remains unclear. In this study, we investigated the expression characteristics of KLF15, Bcat2…”

“…The effects of fasting on expression of core circadian clocks and BCAA metabolism in skeletal muscle of fish have been studied (19,33,34) ; however, the molecular mechanism of circadian rhythm regulating adaptive metabolism of fish skeletal muscle under fasting remains unclear. In this study, we investigated the expression characteristics of KLF15 , Bcat2 and fifteen core circadian clock genes in fast muscle of Chinese perch ( Siniperca chuatsi ) during short-term fasting, then analysed the correlation between their expression to screen out the clock gene involved in dynamic regulation of BCAA metabolism, and finally demonstrated that the circadian rhythm regulates BCAA metabolism in Chinese perch during short-term fasting by Clock-KLF15-Bcat2 pathway.…”