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进食节律差异调节棕色脂肪组织的生物钟与代谢基因昼夜节律

陈江慧^1,2, 周玫余², 黄荣凤², 辛浩然², 成姝婷³, 李旻典², 仝识非^2,*

¹重庆医科大学附属第三医院心血管内科，重庆 401120；²陆军军医大学第一附属医院心内科，代谢生物钟与心血管病中心，重庆 400038；³四川大学华西基础医学与法医学院，国家卫生健康委员会时间生物学重点实验室，成都 610041

摘要

感知光暗节律的主生物钟与进食节律共同调节外周组织器官生物钟系统。进食节律调节外周组织器官生物钟的效应存在组织特异性。本研究旨在阐明进食节律对棕色脂肪组织(brown adipose tissue, BAT)生物钟和代谢基因转录本昼夜节律的调节作用。利用野生型和Per1/2纯合突变C57BL/6小鼠构建时间限制性进食(time-restricted feeding, TRF)动物模型，用RT-qPCR研究性别、限制进食持续时间、行为节律干预和核心生物钟基因缺失等因素对BAT生物钟及代谢基因转录本适应进食节律能力的影响；具有代表性的生物钟基因为Bmal1、Nr1d1、Dbp和Per2，具有代表性的代谢基因有解偶联蛋白1 (uncoupling protein 1, Ucp1)、调节糖酵解通量的6-磷酸果糖激酶-2/果糖-2,6-二磷酸酶3 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3, Pfkfb3)、调节三羧酸循环的丙酮酸脱氢酶激酶同工酶4 (pyruvate dehydrogenase kinase isozyme 4, Pdk4)，以及调节线粒体脂肪酸氧化的肉碱棕榈酰基转移酶1A (carnitine palmitoyltransferase 1A, Cpt1a)。结果显示，白天限制性进食(daytime- restricted feeding, DRF)干预7或36 d后，雌鼠生物钟基因转录本昼夜节律相位仅发生轻微迁移，而雄鼠部分生物钟基因昼夜节律消失。DRF诱导解偶联基因Ucp1昼夜节律，并使糖脂代谢基因Pfkfb3、Pdk4和Cpt1a转录本昼夜节律发生>7 h的相位迁移。持续光照促进DRF调节生物钟基因转录本相位，但除Pdk4外的代谢基因转录本未表现出昼夜节律。而在持续黑暗和核心生物钟基因Per1/2双敲除条件下，DRF仍能驱动Bmal1和Dbp产生节律，但不驱动Nr1d1、Ucp1、Pfkfb3、Cpt1a昼夜节律产生。上述结果提示，BAT生物钟适应进食节律改变的能力弱，且存在性别差异。BAT生物钟受到主生物钟与DRF的拮抗调节作用，而DRF依赖生物钟调节Ucp1、Pfkfb3、Cpt1a等代谢基因的昼夜节律。

关键词： 代谢生物钟; 时间限制性进食; 生物钟; 棕色脂肪组织; 解偶联蛋白1; 糖代谢; 脂代谢

Feeding rhythm entrains circadian metabolism genes, but not the circadian clock, in brown adipose tissue

CHEN Jiang-Hui^1,2, ZHOU Mei-Yu², HUANG Rong-Feng², XIN Hao-Ran², CHENG Shu-Ting³, LI Min-Dian², TONG Shi-Fei^2,*

¹Department of Cardiology, the Third Affiliated Hospital of Chongqing Medical University, Chongqing 401120, China；²Department of Cardiology and the Center for Circadian Metabolism and Cardiovascular Disease, the First Affiliated Hospital of Army Medical University, Chongqing 400038, China；³NHC Key Laboratory of Chronobiology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu 610041, China

Abstract

The central circadian clock and feeding rhythm coordinately reset peripheral circadian clocks. Emerging evidence suggests that feeding rhythm resets peripheral circadian clocks in a tissue-specific manner. This study aimed to determine whether and how feeding rhythm regulates circadian rhythms of the circadian clock and metabolic genes in brown adipose tissue (BAT). We applied different regimens of time-restricted feeding (TRF) in wildtype and Per1/2 deficient C57BL/6 mice, and quantified the effects of sex, treatment duration, constant light, and circadian clock on circadian rhythms of the BAT circadian clock and metabolic genes by RT-qPCR; Representative circadian clock genes are Bmal1, Nr1d1, Dbp, and Per2, and representative metabolic genes are uncoupling protein 1 (Ucp1), 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (Pfkfb3) that controls the flux through glycolysis, pyruvate dehydrogenase kinase isozyme 4 (Pdk4) gating the tricarboxylic acid cycle, and carnitine palmitoyltransferase 1A (Cpt1a) that controls mitochondrial fatty acid oxidation. The results showed that, daytime-restricted feeding (DRF) moderately shifted the phase of the BAT circadian clock in female mice within 7 or 36 d, and resulted in the loss of circadian rhythm in Dbp and Per2 transcripts in males. DRF induced de novo oscillation of the Ucp1 transcript, and shifted the phase of representative metabolic genes, such as Pfkfb3, Pdk4, and Cpt1a, more than 7 h. Constant light is known to disrupt the synchrony of the central circadian clock. The results showed that constant light promoted phase entrainment of the circadian clock by DRF in BAT, but abolished the oscillation of the metabolic genes (except for Pdk4). Despite combined treatment with Per1/2 deficiency and constant darkness, DRF was sufficient to drive circadian rhythms of Bmal1 and Dbp, but not those of Nr1d1, Ucp1, Pfkfb3, and Cpt1a. Overall, the circadian clock of BAT has weak adaptation to altered feeding rhythms and sex differences. The central circadian clock antagonizes DRF in the entrainment of the BAT circadian clock, whereas DRF resets circadian rhythms of metabolic genes, such as Ucp1, Pfkfb3, and Cpt1a, in a circadian clock-dependent manner.

Key words: circadian metabolism; time-restricted feeding; circadian clock; brown adipose tissue; uncoupling protein 1; glucose metabolism; lipid metabolism

收稿日期：　　录用日期：

通讯作者：仝识非　　E-mail: 651050@hospital.cqmu.edu.cn

DOI: 10.13294/j.aps.2022.0035

引用本文：

陈江慧, 周玫余, 黄荣凤, 辛浩然, 成姝婷, 李旻典, 仝识非. 进食节律差异调节棕色脂肪组织的生物钟与代谢基因昼夜节律[J]. 生理学报 2022; 74 (5): 726-736.

CHEN Jiang-Hui, ZHOU Mei-Yu, HUANG Rong-Feng, XIN Hao-Ran, CHENG Shu-Ting, LI Min-Dian, TONG Shi-Fei. Feeding rhythm entrains circadian metabolism genes, but not the circadian clock, in brown adipose tissue. Acta Physiol Sin 2022; 74 (5): 726-736 (in Chinese with English abstract).