Capsaicin alleviates the hepatic clock gene disruption and gut microbiota dysbiosis in circadian rhythm disorder mouse model

As the body’s internal clock,the circadian rhythm regulates the energy expenditure,appetite,and sleep.There exists a close relationship between the host circadian rhythm and gut microbiota.In this work,a circadian disorder mouse model induced by constant darkness(CD)was constructed to investigate the regulating effects of capsaicin(CAP)on disturbances of metabolism homeostasis and gut microbiota in the respect of circadian rhythm-related mechanisms.Our results indicated that CAP reduced weight gain induced by circadian rhythm disorder in mice by inhibiting fat accumulation in liver and adipose tissue.The rhythmic expressions of circadian clock genes and lipid-metabolism related genes in liver were also recovered by CAP.Microbial study using 16S rRNA sequencing revealed that CAP modulated the gut microbiota richness,diversity and composition,and restored diurnal oscillations of gut microbes at the phylum and family level.These results indicated that CAP could alleviate CD-induced hepatic clock gene disruption and gut microbiota dysbiosis in mice,providing theoretical basis for CAP to be used as a muti-functional ingredient with great healthpromoting effects.

Genes related to circadian rhythm are involved in regulating tuberization time in potato

Early tuberization,a short period from stolon occurrence to tuber formation,is one of the major characteristics of a good early-maturing potato cultivar,while the regulatory mechanism of tuberization time(TT)is still unclear.In this study,two tetraploid cultivars,Zhongshu 3(Z3)and Zhongshu 18(Z18),with short and long TT respectively,were examined to reveal regulatory genes related to TT using RNA sequencing of tissue samples taken during stolon occurrence,stolon swelling and tuber formation.Cluster analysis showed that the gene expression patterns at the stolon swelling and tuber formation stages were significantly different from those at stolon occurrence in both Z3 and Z18.Therefore,we screened the differentially expressed genes(DEGs)at stolon swelling and tuber formation and compared them to those at stolon occurrence.A total of 3085 DEGs were specifically identified and analyzed according to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment,and DEGs involved in starch and sucrose metabolism,plant hormone signal transduction and plant circadian clock were significantly enriched.The circadian clock genes were significantly differentially expressed between Z3 and Z18,revealing an important role for the plant circadian pathway in regulating TT.Furthermore,three candidate genes,StGI,StPRR and StEFM involved in circadian regulation and significantly differentially expressed between Z3 and Z18,were discovered and confirmed by qRT-PCR.The results provide valuable information for understanding the regulatory mechanisms of potato TT and represent a step toward breeding early-maturing potato cultivars.

Diabetes mellitus and glymphatic dysfunction:Roles for oxidative stress,mitochondria,circadian rhythm,artificial intelligence,and imaging

Diabetes mellitus(DM)is a debilitating disorder that impacts all systems of the body and has been increasing in prevalence throughout the globe.DM represents a significant clinical challenge to care for individuals and prevent the onset of chronic disability and ultimately death.Underlying cellular mechanisms for the onset and development of DM are multi-factorial in origin and involve pathways associated with the production of reactive oxygen species and the generation of oxidative stress as well as the dysfunction of mitochondrial cellular organelles,programmed cell death,and circadian rhythm impairments.These pathways can ultimately involve failure in the glymphatic pathway of the brain that is linked to circadian rhythms disorders during the loss of metabolic homeostasis.New studies incorporate a number of promising techniques to examine patients with metabolic disorders that can include machine learning and artificial intelligence pathways to potentially predict the onset of metabolic dysfunction.

Effect of Xiaoaiping on the expression of circadian clock genes in human hepatoma HepG2 cells

Objective： Investigation of the effect of Xiaoaiping on the expression of circadian clock genes in human hepatoma HepG2 cells. Methods： Selecting the HepG2 cells in the logarithmic growth phase and assigning them to Xiaoaiping injection （XAP） group and control group. The two groups were treated with 75 mg/mL XAP or the same dose of normal saline. After 72 h of treatment, real-time PCR was used to detect the expression of circadian clock genes in HepG2 cells and Western Blot technology was used to detect the expression of related proteins. Results： The mRNA expression levels of PER1, NPAS2, NR1D1, and DEC1 in the XAP group was significantly higher than that in the control group （P〈 0.05）, while the mRNA expression levels of PER3, BMAL1, DEC2, and RORA were significantly lower in the XAP group than in the control group （P 〈 0.05）, and there was no significant difference between the mRNA expression levels of PER2, CRY1, CRY2, and TIM. Of course, the proteins＇ expression levels of the genes we had detected such as PERle3, CRYI-2, CLOCK, BMAL1 by Western Blot were consistent with the real-time PCR results above. Conclusion： XAP affects the expression of circadian clock genes in HepG2 cells.

The Clock gene clone and its circadian rhythms in Pelteobagrus vachelli

The Clock gene,a key molecule in circadian systems,is widely distributed in the animal kingdom. We isolated a 936-bp partial c DNA sequence of the C lock gene( Pva- clock) from the darkbarbel catfish P elteobagrus vachelli that exhibited high identity with C lock genes of other species of fish and animals(65%–88%). The putative domains included a basic helix-loop-helix(b HLH) domain and two period-ARNT-single-minded(PAS) domains,which were also similar to those in other species of fish and animals. P va- Clock was primarily expressed in the brain,and was detected in all of the peripheral tissues sampled. Additionally,the pattern of P va- Clock expression over a 24-h period exhibited a circadian rhythm in the brain,liver and intestine,with the acrophase at zeitgeber time 21:35,23:00,and 23:23,respectively. Our results provide insight into the function of the molecular C lock of P. vachelli.

Effects of Chronotherapy of Benazepril on the Diurnal Profile of RAAS and Clock Genes in the Kidney of 5/6 Nephrectomy Rats

Summary： This study investigated the effects of benazepril administered in the morning or evening on the diurnal variation of renin-angiotensin-aldosterone system （RAAS） and clock genes in the kidney. The male Wistar rat models of 5/6 subtotal nephrectomy （STNx） were established. Animals were ran- domly divided into 4 groups： sham STNx group （control）, STNx group, morning benazepril group （MB） and evening benazepril group （EB）. Benazepril was intragastfically administered at a dose of 10 mg/kg/day at 07：00 and 19：00 in the MB group and EB group respectively for 12 weeks. All the animals were synchronized to the light：dark cycle of 12：12 for 12 weeks. Systolic blood pressure （SBP）, 24-h urinary protein excretion and renal function were measured at 11 weeks. Blood samples and kidneys were collected every 4 h throughout a day to detect the expression pattern of renin activity （RA）, angio- tensin Ⅱ （Ang Ⅱ ） and aldosterone （Aid） by radioimmunoassay （RIA） and the mRNA expression profile of clock genes （bmall, dbp and per2） by real-time PCR at 12 weeks. Our results showed that no signifi- cant differences were noted in the SBP, 24-h urine protein excretion and renal function between the MB and EB groups. There were no significant differences in average Aid and RA content of a day between the MB group and EB group. The expression peak of bmall mRNA was phase-delayed by 4 to 8 h, and the diurnal variation of per2 and dbp mRNA diminished in the MB and EB groups compared with the control and STNx groups. It was concluded when the similar SBP reduction, RAAS inhibition and clock gene profile were achieved with optimal dose of benazepril, morning versus evening dosing of benazepril has the same renoprotection effects.

Effects of 72 Hours Sleep Deprivation on Liver Circadian Clock Gene Expression and Oxidative Stress in Rats

Objective: To investigate the effects of 72 hours continuous sleep deprivation (SD) on circadian clock gene expression and oxidative stress in the rat liver. Methods: Twenty healthy male Sprague-Dawley rats were divided into 2 groups (n = 10 each) using a random number table: normal control group (group C), sleep deprivation group (group SD). Group SD was treated with a modified multiple platform water environment method. After 72 hours sleep deprived, the levels of AST (Aspartate transaminase ) and ALT (Alanine aminotransferase) in serum were determined. The contents of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the liver tissue of the rats were examined in both two groups. The expression levels of CLOCK, BMAL1 and CRY1 protein in liver tissue were examined by Western blotting. Results: Compared with group C, the content of MDA, and the levels of AST and ALT in serum were significantly increased (P Conclusion: 72 hours continuous sleep deprivation can downregulate the expression of circadian clock gene and promote oxidative stress in rats.

Circadian rhythm disruption and endocrine-related tumors

This review delved into the intricate relationship between circadian clocks and physiological processes,emphasizing their critical role in maintaining homeo-stasis.Orchestrated by interlocked clock genes,the circadian timekeeping system regulates fundamental processes like the sleep-wake cycle,energy metabolism,immune function,and cell proliferation.The central oscillator in the hypothalamic suprachiasmatic nucleus synchronizes with light-dark cycles,while peripheral tissue clocks are influenced by cues such as feeding times.Circadian disruption,linked to modern lifestyle factors like night shift work,correlates with adverse health outcomes,including metabolic syndrome,cardiovascular diseases,infec-tions,and cancer.We explored the molecular mechanisms of circadian clock genes and their impact on metabolic disorders and cancer pathogenesis.Specific associ-ations between circadian disruption and endocrine tumors,spanning breast,ovarian,testicular,prostate,thyroid,pituitary,and adrenal gland cancers,are highlighted.Shift work is associated with increased breast cancer risk,with PER genes influencing tumor progression and drug resistance.CLOCK gene expression correlates with cisplatin resistance in ovarian cancer,while factors like aging and intermittent fasting affect prostate cancer.Our review underscored the intricate interplay between circadian rhythms and cancer,involving the regulation of the cell cycle,DNA repair,metabolism,immune function,and the tumor microenvir-onment.We advocated for integrating biological timing into clinical consider-ations for personalized healthcare,proposing that understanding these connec-tions could lead to novel therapeutic approaches.Evidence supports circadian rhythm-focused therapies,particularly chronotherapy,for treating endocrine tumors.Our review called for further research to uncover detailed connections between circadian clocks and cancer,providing essential insights for targeted treatments.We emphasized the importance of public health interventions to mitigate lifestyle-related circadian disruptions and underscored the critical role of circadian rhythms in disease mechanisms and therapeutic interventions.

永恒蛋白基因/周期蛋白基因介导多条通路在昼夜节律中的作用

背景:昼夜节律与大多数哺乳动物及昆虫的生命活动息息相关。永恒蛋白基因作为编码永恒蛋白基因-周期蛋白基因复合物的关键成分在产生昼夜节律过程中起到十分关键的作用,但其在昼夜节律中的作用机制仍不清楚。目的:通过整理永恒蛋白基因、周期蛋白基因、昼夜节律、环境及隐花色素基因之间的关系,更加全面地认识昼夜循环的入核、积累机制及环境对昼夜节律的影响。方法:应用计算机在Web of Science核心合集、PubMed数据库及CNKI中进行检索,以“永恒蛋白基因,周期蛋白基因,昼夜节律,环境”为中文检索词,以“Timeless,Period,circadian rhythm,environment”为英文检索词,通过全文阅读逐步排除非相关文献,最终纳入126篇文献进行综述。结果与结论:在昼夜时钟中,昼夜自发输出周期蛋白kaput和CYCLE激活永恒蛋白基因/周期蛋白基因,永恒蛋白基因调控周期蛋白基因的入核机制及稳定性,而周期蛋白基因也可以通过一些机制单独入核。酪蛋白激酶2、Shaggy蛋白激酶及双倍时间基因都可以通过磷酸化永恒蛋白基因/周期蛋白基因的方式来调节昼夜节律,参与转录。隐花色素基因介导的永恒蛋白基因降解对转录的完整性有十分重要的作用。环境因素、膳食方式等外界因素均可以通过永恒蛋白基因/周期蛋白基因对昼夜节律产生影响,而限时进食可作为一种改善昼夜节律紊乱的有效方法。

circadian clock circuitry in colorectal cancer

Colorectal cancer is the most prevalent among digestive system cancers.Carcinogenesis relies on disrupted control of cellular processes,such as metabolism,proliferation,DNA damage recognition and repair,and apoptosis.Cell,tissue,organ and body physiology is characterized by periodic fluctuations driven by biological clocks operating through the clock gene machinery.Dysfunction of molecular clockworks and cellular oscillators is involved in tumorigenesis,and altered expression of clock genes has been found in cancer patients.Epidemiological studies have shown that circadian disruption,that is,alteration of bodily temporal organization,is a cancer risk factor,and an increased incidence of colorectal neoplastic disease is reported in shift workers.In this review we describe the involvement of the circadian clock circuitry in colorectal carcinogenesis and the therapeutic strategies addressing temporal deregulation in colorectal cancer.

Common genetic variations in CLOCK transcription factor are associated with nonalcoholic fatty liver disease

To investigate the role of gene variants and derived haplotypes of the CLOCK transcription factor in nonalcoholic fatty liver disease （NAFID） and their relation with the disease severity.METHODS： A total of 136 patients with NAFLD and 64 healthy individuals were studied. Liver biopsy was performed in 91 patients. Six tag SNPs showing a minor allele frequency 〉 10% （rs1554483 C/G; rs11932595 A/G; rs4580704 C/G; rs6843722 A/C; rs6850524 C/G and rs4864548 A/G） encompassing 117 kb of chromosome 4 and representing 115 polymorphic sites （P 〉 0.8） were genotyped. RESULTS： rs11932595 and rs6843722 showed significant associations with NAFLD （empiric P = 0.0449 and 0.023, respectively）. A significant association was also observed between clinical or histologic spectrum of NAFLD and rs1554483 （empiric P = 0.0399）, rs6843722 （empiric P = 0.0229） and rs6850524 （empiric P = 0.00899） and between fibrosis score and rs1554483 （empiric P = 0.02697）, rs6843722 （empiric P = 0.01898） and rs4864548 （empiric P = 0.02697）. Test of haplotypic association showed that CLOCK gene variant haplotypes frequencies in NAFLD individuals significantly differed from those in controls （empiric P = 0.0097）.CONCLUSION： Our study suggests a potential role of the CLOCK polymorphisms and their haplotypes insusceptibility to NAFLD and disease severity.

Hepatitis B and circadian rhythm of the liver

The circadian rhythm in humans is determined by the central clock located in the hypothalamus’s suprachiasmatic nucleus,and it synchronizes the peripheral clocks in other tissues.Circadian clock genes and clock-controlled genes exist in almost all cell types.They have an essential role in many physiological processes,including lipid metabolism in the liver,regulation of the immune system,and the severity of infections.In addition,circadian rhythm genes can stimulate the immune response of host cells to virus infection.Hepatitis B virus(HBV)infection is the leading cause of liver disease and liver cancer globally.HBV infection depends on the host cell,and hepatocyte circadian rhythm genes are associated with HBV replication,survival,and spread.The core circadian rhythm proteins,REV-ERB and brain and muscle ARNTL-like protein 1,have a crucial role in HBV replication in hepatocytes.In addition to influencing the virus’s life cycle,the circadian rhythm also affects the pharmacokinetics and efficacy of antiviral vaccines.Therefore,it is vital to apply antiviral therapy at the appropriate time of day to reduce toxicity and improve the effectiveness of antiviral treatment.For these reasons,understanding the role of the circadian rhythm in the regulation of HBV infection and host responses to the virus provides us with a new perspective of the interplay of the circadian rhythm and anti-HBV therapy.Therefore,this review emphasizes the importance of the circadian rhythm in HBV infection and the optimization of antiviral treatment based on the circadian rhythm-dependent immune response.

Molecular insights into the circadian clock in marine diatoms

The circadian clock is a fundamental endogenous mechanism of adaptation that coordinates the physiology and behavior of most organisms with diel variations in the external environment to maintain temporal homeostasis.Diatoms are the major primary producers in the ocean.However,little is known about the circadian clock in marine diatoms compared with other organisms.Here,we investigated circadian clock genes,their expression patterns,and responses to environmental stimuli such as light,nitrogen and phosphorus in two marine diatoms,Skeletonema costatum and Phaeodactylum tricornutum,using a combination of q RT-PCR and bioinformatic analysis.We identified 17 and 18 circadian clock genes in P.tricornutum and S.costatum,respectively.Despite significant evolutionary differences,these genes were similar to those of the higher plant Arabidopsis.We also established a molecular model for the marine diatom circadian clock comprising an input pathway,core oscillator,output pathway,and valve effector.Notably,the expression patterns of core clock genes(circadian clock associated 1(CCA1),late elongated hypocotyl(LHY)and timing of cab 1(TOC1))in both species differed from those of terrestrial plants.Furthermore,the expression of these genes was influenced by variations in ambient light,nitrogen and phosphorus availability.Although marine diatoms and higher plants share common circadian clock components,their clock genes have diverged throughout evolution,likely as a result of adapting to contrasting environments.

柴胡皂苷A调节cAMP/PKA/CREB信号通路对失眠大鼠的改善作用及机制研究

目的基于cAMP/PKA/CREB通路探讨柴胡皂苷A对失眠大鼠的改善作用及机制。方法将75只SD大鼠随机分为空白组、模型组、柴胡皂苷A低剂量组(0.625 mg·kg^(-1))、柴胡皂苷A高剂量组(2.500 mg·kg^(-1))、艾司唑仑组(0.1 mg·kg^(-1)),每组15只。采用腹腔注射苯丙氨酸(PCPA,0.1 mg·kg^(-1))复制失眠大鼠模型。观察大鼠一般情况及昼夜节律;采用戊巴比妥钠翻正实验测定大鼠睡眠潜伏期及睡眠持续时间;观测大鼠睡眠时相,记录慢波睡眠第1期(SWS1)、慢波睡眠第2期(SWS2)、快速眼球运动睡眠期(REMS)时长以及总睡眠时长(TST);qRT-PCR法测定下丘脑节律基因Clock、Bmal1 mRNA及钟控基因Rev-erbα、RorαmRNA的表达水平;免疫荧光法测定海马组织NeuN表达水平;ELISA法测定脑组织中的cAMP水平;Western Blot法测定脑组织中Clock、Bmal1、Rev-erbα、Rorα及cAMP/PKA/CREB通路相关蛋白表达水平。结果与空白组比较,模型组大鼠昼伏夜出的节律紊乱,极度兴奋,易激惹,睡眠减少;睡眠潜伏期明显延长(P<0.05),睡眠持续时间及SWS1、SWS2、REMS、TST均明显缩短(P<0.05);神经元排列紊乱,NeuN阳性神经元IOD值明显降低(P<0.05);脑组织Clock、Bmal1、Rev-erbα、RorαmRNA及蛋白表达水平明显降低(P<0.05);脑组织cAMP、p-PKA/PKA、p-CREB/CREB蛋白表达水平明显降低(P<0.05)。与模型组比较,给药组大鼠的攻击性明显减弱,昼伏夜出有节律性,活动减少,睡眠增多;睡眠潜伏期明显缩短(P<0.05),睡眠持续时间及SWS1、SWS2、REMS、TST均明显延长(P<0.05);神经元排列紊乱情况有所恢复,NeuN阳性神经元IOD值明显升高(P<0.05);脑组织Clock、Bmal1、Rev-erbα、RorαmRNA及蛋白表达水平明显升高(P<0.05);脑组织cAMP、p-PKA/PKA、p-CREB/CREB蛋白表达水平明显升高(P<0.05)。结论柴胡皂苷A可能通过激活cAMP/PKA/CREB通路改善失眠大鼠的昼夜节律。

Study on the Mechanism of Shimian Granules (SMG) against Depression via Regulating Circadian Rhythms

Background:According to the World Health Organization,about 350 million people worldwide are suffering from depression.It's reported that depression has been linked to several circadian rhythm perturbations,suggesting a disruption of the circadian clock system in affective disorders.The present study investigates the possible molecular mechanism of Shimian granules(SMG)in treating depression via restoring disrupted circadian rhythms.Method:Firstly,network pharmacology approach was used to identify the compounds and potential targets of SMG in TCMIP and BATMAN-TCM database.Secondly,the differential expression genes were obtained by gene expression profiling in GEO database(GSE56931,GSE98793).Further,protein-protein interactions(PPI)network was used to screen out core targets by STRING v11.Moreover,functional enrichment was carried out in DAVID database.Conclusively,the"herbs-compounds-targets-pathways"network was established to explore the mechanism of SMG in the treatment of depression.Result:It was found out that 65 compounds,18 targets and three pathways contributed to SMG in treating depression by regulating disrupted circadian rhythms,which might relate to core targets TNF,IL10,VDR in cAMP and calcium signaling pathway.Conclusion:Network pharmacology combined with gene expression profiling exhibited a powerful means to investigate the possible mechanism of formula,which contributes to theoretical basis for further study of SMG in the treatment of depression.

生物节律与子痫前期的相关性

子痫前期(preeclampsia,PE)是一种常见的妊娠并发症,危害母婴健康,更是一个严重的国际公共卫生问题。尽管已证实PE的高危因素包括肥胖、糖尿病和妊娠前高血压等,但其发病机制仍未完全阐明。哺乳动物中绝大多数的生理过程由生物节律调控,生物节律的破坏被证实与众多疾病相关,如心血管疾病、糖尿病和乳腺癌等。尽管PE具有一系列时间生物节律的特征性表现,如PE患者的血压24 h节律变异性、“反勺状”血压与更严重的靶器官损伤有关、夜间服用阿司匹林的预防保护作用更优异等,但生物节律的变异是否为PE的危险因素,抑或PE本身是否与异常的生物节律相关,目前尚未明确。综述生物节律与PE的相关性,包括胎盘的钟基因表达及其与PE的关系、血压的生物节律、PE预防的时间治疗学、生物节律的破坏与PE风险性,以启示今后深入研究生物节律/钟基因与PE之间潜在关联的必要性。

生物钟基因Bmal1、Per2在血液肿瘤细胞株Raji、Hut-78、OCI-LY8及HL-60中的昼夜表达规律

目的通过检测生物钟基因Bmal1、Per2在血液肿瘤细胞株Raji、Hut-78、OCI-LY8及HL-60细胞中不同时间点的mRNA表达情况,探讨其与血液肿瘤发生发展的可能关系。方法血液肿瘤细胞株Raji、Hut-78、LY-8、HL-60经血清休克法诱导节律后,RT-PCR法检测生物钟基因Bmal1及Per2在不同时间点的mRNA转录水平,以时间为变量分别对其转录量进行余弦函数拟合,通过余弦函数预测基因转录高峰及低谷时段。结果Bmal1和Per2基因表达在OCI-LY8、Hut-78、HL-60细胞中呈现昼夜节律(P<0.05);Raji细胞内Bmal1基因无节律性表达(P>0.05),而Per2基因呈昼夜节律表达(P<0.05)。结论生物钟基因Per2和(或)Bmal1在多种血液肿瘤细胞株内呈昼夜节律性表达,其可能参与血液肿瘤的发生发展。

摩腹联合电针透穴法对失眠大鼠生物钟相关基因及神经递质表达的影响

目的探讨摩腹联合电针透穴法对失眠大鼠生物钟基因Clock、BMAL1、PER1表达及神经递质乙酰胆碱(ACh)、谷氨酸(Glu)含量的影响及可能的作用机制。方法50只SD雄性大鼠随机分为正常组、模型组、摩腹组、电针透穴组和联合组,每组10只。除正常组外,采用腹腔注射对氯苯丙氨酸建立失眠大鼠模型。摩腹组进行腹部按摩,电针透穴组采用平刺法,百会透神庭、三阴交透阴陵泉(双侧)、神门透内关(双侧),电针仪疏密波,频率1Hz/20Hz,联合组摩腹后进行电针透穴治疗,各组均1次/d,连续7d,正常组和模型组不予干预。HE染色观察下丘脑组织神经元细胞形态变化,RT-qPCR检测下丘脑组织Clock、BMAL1、PER1 mRNA表达,免疫组化染色检测下丘脑组织Clock、BMAL1、PER1表达,Western blot检测下丘脑组织Clock、BMAL1、PER1蛋白表达,ELISA检测血清ACh、Glu含量。结果与正常组比较,模型组大鼠入睡潜伏期延长,睡眠持续时间缩短,下丘脑组织细胞结构破坏严重、呈空泡样变化,神经元细胞数量减少,下丘脑组织Clock、BMAL1mRNA和蛋白表达升高,PER1mRNA和蛋白表达降低,血清ACh、Glu含量增加,差异均有统计学意义(P<0.05);与模型组比较,摩腹组、电针透穴组和联合组均能缩短入睡潜伏期,延长睡眠持续时间,改善下丘脑神经元细胞形态,降低下丘脑组织Clock、BMAL1mRNA和蛋白表达,上调PER1mRNA和蛋白表达,减少血清ACh、Glu含量,差异均有统计学意义(P<0.05),以联合组作用最显著(P<0.05)。结论摩腹联合电针透穴法能改善大鼠失眠状况,其机制可能与调控生物钟基因Clock、BMAL1、PER1mRNA和蛋白表达及神经递质含量有关。

时钟基因调控低氧训练肥胖大鼠白色脂肪组织棕色化

背景:低氧训练可以促进机体脂肪的降解,外界环境变化可影响动物昼夜节律,但昼夜节律变化对脂肪组织棕色化及脂肪降解的调控机制尚不明确。目的:阐明时钟基因对低氧训练大鼠附睾脂肪组织棕色化的调控机制。方法:喂养高脂饲料构建肥胖大鼠模型,造模成功后抽取40只肥胖大鼠随机分为4组,即常氧安静组、低氧安静组、常氧训练组、低氧训练组,每组10只,进行4周的干预。安静组大鼠不实施干预;低氧组大鼠全天生活在氧浓度为13.6%的低氧仓中;训练组第1周为适应性训练,后3周训练速度和时长保持不变。测量肥胖大鼠体质量、体长和肾周脂肪质量;并使用血脂生化检测试剂盒检测肥胖大鼠血清中三酰甘油、总胆固醇、低密度脂蛋白胆固醇以及高密度脂蛋白胆固醇水平;油红O染色观察肝脏脂肪含量变化;苏木精-伊红染色评价各组大鼠附睾脂肪组织棕色化变化;转录组测序技术结合生物信息学分析脂肪组织中转录组水平变化;采用qRT-PCR检测附睾脂肪组织中PGC-1α、Beclin1、KLF2、Perilipin1 mRNA的表达变化情况。结果与结论:①低氧训练干预使营养性肥胖大鼠体质量、脂体比、Lees’s指数、血清总胆固醇、三酰甘油以及低密度脂蛋白胆固醇浓度显著降低(P<0.01),高密度脂蛋白胆固醇浓度显著升高(P<0.01);②油红O染色和苏木精-伊红染色显示,相比于常氧安静组、低氧安静组和常氧训练组,低氧训练更能有效促进大鼠肝脏组织中脂肪动员和附睾旁脂肪组织棕色化;③转录组测序结果显示,低氧训练时钟基因Dbp、Nr1d1、Sik1以及脂肪组织棕色化基因Ppargc1a(PGC-1α)等表达显著上调(P<0.05),而Arntl(Bmal1)显著下调(P<0.05),同时伴随物质代谢相关基因的表达增强;④qRT-PCR结果证实低氧训练时脂肪组织棕色化基因PGC-1α和脂代谢基因Perilipin1表达量均显著升高(P<0.01);⑤结果证实时钟基因在低氧训练促进脂肪组织棕色化过程中起到重要作用。