The circadian clock is an important internal time regulatory system for a range of physiological and behavioral rhythms within living organisms.Testosterone,as one of the most critical sex hormones,is essential for th...The circadian clock is an important internal time regulatory system for a range of physiological and behavioral rhythms within living organisms.Testosterone,as one of the most critical sex hormones,is essential for the development of the reproductive system,maintenance of reproductive function,and the overall health of males.The secretion of testosterone in mammals is characterized by distinct circadian rhythms and is closely associated with the regulation of circadian clock genes.Here we review the central and peripheral regulatory mechanisms underlying the influence of circadian clock genes upon testosterone synthesis.We also examined the specific effects of these genes on the occurrence,development,and treatment of common male diseases,including late-onset hypogonadism,erectile dysfunction,male infertility,and prostate cancer.展开更多
Clock genes create a complicated molecular time-keeping system consisting of multiple positive and negative feedback loops at transcriptional and translational levels. This circadian system coordinates and regulates m...Clock genes create a complicated molecular time-keeping system consisting of multiple positive and negative feedback loops at transcriptional and translational levels. This circadian system coordinates and regulates multiple cellular procedures implicated in cancer development such as metabolism, cell cycle and DNA damage response. Recent data support that molecules such as CLOCK1, BMAL1 and PER and CRY proteins have various effects on c-Myc/p21 and Wnt/β-catenin pathways and influence multiple steps of DNA damage response playing a critical role in the preservation of genomic integrity in normal and cancer cells. Notably, all these events have already been related to the development and progression of colorectal cancer (CRC). Recent data highlight critical correlations between clock genes’ expression and pathogenesis, progression, aggressiveness and prognosis of CRC. Increased expression of positive regulators of this circadian system such as BMAL1 has been related to decrease overall survival while decreased expression of negative regulators such as PER2 and PER3 is connected with poorer differentiation, increased aggressiveness and worse prognosis. The implications of these molecules in DNA repair systems explain their involvement in the development of CRC but at the same time provide us with novel targets for modern therapeutic approaches for patients with advanced CRC.展开更多
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 Wist...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.展开更多
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...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.展开更多
Mammalian bone is constantly metabolized from the embryonic stage,and the maintenance of bone health depends on the dynamic balance between bone resorption and bone formation,mediated by osteoclasts and osteoblasts.It...Mammalian bone is constantly metabolized from the embryonic stage,and the maintenance of bone health depends on the dynamic balance between bone resorption and bone formation,mediated by osteoclasts and osteoblasts.It is widely recognized that circadian clock genes can regulate bone metabolism.In recent years,the regulation of bone metabolism by non-coding RNAs has become a hotspot of research.MicroRNAs can participate in bone catabolism and anabolism by targeting key factors related to bone metabolism,including circadian clock genes.However,research in this field has been conducted only in recent years and the mechanisms involved are not yet well established.Recent studies have focused on how to target circadian clock genes to treat some diseases,such as autoimmune diseases,but few have focused on the co-regulation of circadian clock genes and microRNAs in bone metabolic diseases.Therefore,in this paper we review the progress of research on the co-regulation of bone metabolism by circadian clock genes and microRNAs,aiming to provide new ideas for the prevention and treatment of bone metabolic diseases such as osteoporosis.展开更多
Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were ra...Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were randomized equally into control group and heat stress group.After exposure to 32℃for 2 weeks in the latter group,the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry.In the cell experiments,cultured rat thoracic aortic endothelial cells(RTAECs)were incubated at 40℃for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA(si-Bmal1)or a negative sequence.In both rat thoracic aorta and RTAECs,the expressions of Bmal1,the cell cycle proteins CDK1,CDK4,CDK6,and cyclin B1,and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting.TUNEL staining was used to detect cell apoptosis in rat thoracic aorta,and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry.Results Compared with the control rats,the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1,cyclin B1 and CDK1 in the thoracic aorta(P<0.05).In cultured RTAECs,heat stress caused significant increase of Bmal1,cyclin B1 and CDK1 protein expression levels,which were obviously lowered in cells with prior si-Bmal1 transfection.Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2.Conclusion Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells,which can be partly alleviated by suppressing Bmal1 expression.展开更多
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 vac...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.展开更多
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 di...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.展开更多
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 an...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.展开更多
This review explores the pivotal role of circadian rhythm regulators,particularly the PER genes,in Oral Squamous Cell Carcinoma(OSCC).As key constituents of the biological clock,PERs exhibit a downregulated expression...This review explores the pivotal role of circadian rhythm regulators,particularly the PER genes,in Oral Squamous Cell Carcinoma(OSCC).As key constituents of the biological clock,PERs exhibit a downregulated expression pattern in OSCC,and the expression levels of PERs in OSCC patients are correlated with a favorable prognosis.PERs impact the occurrence and development of OSCC through multiple pathways.In the regulation of cell proliferation,they can function not only through cell cycle regultion but also via metabolic pathways.For example,PER1 can interact with receptors for activated C kinase 1(RACK1)and phosphatidylinositol 3-kinase(PI3K)through its PAS domain to inhibit glycolysis and thereby reduce cell proliferation.Regarding the regulation of cell death,PERs mediate various types of cell death in OSCC cells,such as p53-dependent apoptosis,protein kinase B(AKT)/mammalian target of rapamycin(mTOR)dependent autophagy,or hypoxia-inducible factor l-alpha(HIF-1a)mediated ferroptosis.In regulating epithelia-mesenchymal transition(EMT),PERs can lead to the downregulation of EMT related genes,such as zinc finger E-box binding homeobox 1/2(ZEBI/2),twist family BHLH transcription factor 1/2(TWIST1/2),and Vimentin,thereby influencing the migration and invasion capabilities of OSCC cells.In tumor angiogenesis,PERs exert regulatory effects on related factors,such as methionyl aminopeptidase 2(MetAP2)and vascular endothelial growth factor(VEGF).In the tumor immune microenvironment,PERs can inhibit the inhibitor of kappa B kinase(IKK)/nuclear factor kappa B(NF-kB)pathway and programmed cell death ligand 1(PD-L1)expression,thereby enhancing the cytotoxic effect of CD8+T cells on OSCC cells.In-depth studies focusing on elucidating the precise regulatory mechanisms of PERs can facilitate the development of therapeutic strategies targeting PERs,including restoration of PERs expression/activity,targeting PERs-regulated pathways,combination therapies,and chronotherapy.These furnish a theoretical foundation for formulating individualized treatment plans to achieve precise treatment for patients with OSCC.展开更多
As one of the most prevalent malignant tumors,hepatocellular carcinoma(HCC)represents a major global public health burden.Traditionally,HCC pathogenesis has been attributed to chronic liver diseases(viral hepatitis,ci...As one of the most prevalent malignant tumors,hepatocellular carcinoma(HCC)represents a major global public health burden.Traditionally,HCC pathogenesis has been attributed to chronic liver diseases(viral hepatitis,cirrhosis)and aflatoxin exposure.However,with evolving lifestyles and environmental changes,sleep disorders have become increasingly prevalent.Emerging evidence suggest that sleep disorders may contribute to hepatocarcinogenesis through multiple mechanisms,including immunity environment disorder,oxidative stress,metabolic dysregulation,disruption of gut microbiota,and circadian rhythm disruption,thereby influencing disease progression and patient prognosis.This review summarizes epidemiological evidence on the relationship between sleep disorders and HCC incidence,explores the underlying mechanisms through which sleep disorders contribute to HCC,and discusses clinical challenges and potential intervention strategies.Our objective is to provide novel insights into HCC prevention and therapeutic approaches.展开更多
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-contr...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.展开更多
A growing body of evidence indicates that exposure to environmental chemicals can contribute to the etiology of obesity by inappropriately stimulating adipogenesis as well as perturbing lipid metabolism and energy bal...A growing body of evidence indicates that exposure to environmental chemicals can contribute to the etiology of obesity by inappropriately stimulating adipogenesis as well as perturbing lipid metabolism and energy balance. One potential mechanism by which chemical exposure can influence lipid metabolism is through disturbance of circadian rhythms, endogenously-driven cycles of roughly 24 hr in length that coordinate biochemical, physiological, and behavioral processes in all organisms. Here we show for the first time that exposure to endocrine disrupting compounds（EDCs）, including the pesticide tributyltin, two commercial flame retardants, and a UV-filter chemical found in sunscreens,can perturb both circadian clocks and lipid metabolism in vertebrates. Exposure of developing zebrafish to EDCs affects core clock activity and leads to a remarkable increase in lipid accumulation that is reminiscent of the effects observed for longdaysin, a known disruptor of circadian rhythms. Our data reveal a novel obesogenic mechanism of action for environmental chemicals, an observation which warrants further research. Because circadian clocks regulate a wide variety of physiological processes, identification of environmental chemicals capable of perturbing these systems may provide important insights into the development of environmentally-induced metabolic disease.展开更多
The prevalence of artificial lights not only improves the lighting conditions for modern society,but also poses kinds of health threats to human health.Although there are regulations and standards concerning light pol...The prevalence of artificial lights not only improves the lighting conditions for modern society,but also poses kinds of health threats to human health.Although there are regulations and standards concerning light pollution,few of them are based on the potential contribution of improper lighting to diseases.Therefore,a better understanding of the health threats induced by light pollution may promote risk assessment and better regulation of artificial lights,thereby a healthy lighting environment.This review is based on a careful collection of the latest papers from 2018 to 2022 about the health threats of light pollution,both epidemiologically and experimentally.In addition to summing up the novel associations of light pollution with obesity,mental disorders,cancer,etc.,we highlight the toxicological mechanism of light pollution via circadian disruption,since light pollution directly interferes with the natural light-dark cycles,and damages the circadian photoentrainment of organisms.And by reviewing the alternations of clock genes and disturbance of melatonin homeostasis induced by artificial lights,we aim to excavate the profound impacts of light pollution based on accumulating studies,thus providing perspectives for future research and guiding relevant regulations and standards.展开更多
Daily cycles due to Earth’s rotation have led to the evolution of circadian clocks that allow the anticipation of the physiological responses of almost all living organisms to predictable environmental conditions.In ...Daily cycles due to Earth’s rotation have led to the evolution of circadian clocks that allow the anticipation of the physiological responses of almost all living organisms to predictable environmental conditions.In eukaryotes,circadian oscillations rely on endogenous transcriptional-translational feedback loops,autoregulatory mechanisms that ensure the precise control of the clock genes.展开更多
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...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.展开更多
The CRISPR-Cas13 systems have opened a new avenue for RNA detection due to their exceptional programmable collateral activity against ssRNA.However,most high-performance Cas13-based RNA sensors still suffer from some ...The CRISPR-Cas13 systems have opened a new avenue for RNA detection due to their exceptional programmable collateral activity against ssRNA.However,most high-performance Cas13-based RNA sensors still suffer from some drawbacks because of the tradeoffs between readout device complexity and analytical sensitivity,which can limit their viability at the point-of-care(POC).To overcome these shortcomings,we herein report a novel target-responsive POC platform for translating RNA detection into a glucose test.Specifically,this platform combines the advantages of three techniques:a hybrid Cas13a/Cas12a system for both RNA recognition with single-base resolution and cascade enzymatic amplification,a self-sustainable catalytic nucleic acid circuit(SCC)with embedded uracil-base and poly-T bulges for Cas13a-and Cas12amediated collateral cleavage,respectively,and a portable glucose meter(PGM)for simple signal readout.The incorporation of an engineered ssDNA–invertase conjugate in SCC led to RNA-to-glucose signal transduction through the hydrolysis of sucrose to glucose.By targeting a 20-nt conserved region of BMAL1 mRNA(mBMAL1),a key circadian clock gene,we demonstrate that SCC can serve as an excellent CRISPR reporter,enabling the direct detection of unamplified mBMAL1 as low as 0.864 fM concurrently with good discrimination ability for single-base mismatch.More importantly,this integrated platform was successfully applied for POC diagnosis of mBMAL1 from different cell lysates,with results that strongly correlate with RT-PCR.Given its wide adaptability,we anticipate that such a CRISPR-SCC system can be easily modified to quantify other RNA biomarkers associated with circadian rhythm.展开更多
Hibernation is one of the fundamental strategies in response to cold environmental temperatures.During hibernation,the endocrine and circadian systems ensure minimal expenditure of energy for survival.The circadian rh...Hibernation is one of the fundamental strategies in response to cold environmental temperatures.During hibernation,the endocrine and circadian systems ensure minimal expenditure of energy for survival.The circadian rhythms of key hormones,melatonin(MT),corticosterone(CORT),triiodothyronine(T3),and thyroxine(T4),and the underlying molecular regulatory mechanisms of hibernation have been well determined in mammals but not in ectotherms.Here,a terrestrial hibernating species,Asiatic toad(Bufo gargarizans),was employed to investigate the plasma CORT,MT,T3,and T4;and the retina,brain,and liver mRNA expression of the core clock genes,including circadian locomotor output cycles kaput(Clock),brain and muscle ARNT-like 1(Bmal1),cryptochrome(Cry)1 and 2,and period(Per)1 and 2,at 7-time points over a 24-h period under acute cold(1 day at 4℃),and hibernation(45 days at 4℃).Our results showed that the circadian rhythms of the core clock genes were rather unaffected by acute cold exposure in the retina,unlike the brain and liver.In contrast,during hibernation,the liver clock genes displayed significant circadian oscillations,while those in the retina and brain stopped ticking.Furthermore,plasma CORT expressed circadian oscillations in both groups,and T3 in acute cold exposure group,whereas T4 and MT did not.Our results reveal that the plasma CORT and the liver sustain rhythmicity when the brain was not,indicating that the liver clock along with the adrenal clock synergistically maintains the metabolic requirements to ensure basic survival in hibernating Asiatic toads.展开更多
Biological rhythms controlled by the circadian clock are absent in embryonic stem cells （ESCs）. However, they start to develop during the differentiation of pluripotent ESCs to downstream cells. Conversely, biologic...Biological rhythms controlled by the circadian clock are absent in embryonic stem cells （ESCs）. However, they start to develop during the differentiation of pluripotent ESCs to downstream cells. Conversely, biological rhythms in adult somatic cells disappear when they are reprogrammed into induced pluripotent stem cells （iPSCs）. These studies indicated that the development of biological rhythms in ESCs might be closely associated with the maintenance and differentiation of ESCs. The core circadian gene Clock is essential for regulation of biological rhythms. Its role in the development of biological rhythms of ESCs is totally unknown. Here, we used CRISPR/CAS9-mediated genetic editing techniques, to completely knock out the Clock expression in mouse ESCs. By AP, teratoma formation, quantitative real-time PCR and Immunofluorescent staining, we did not find any dif- ference between Clock knockout mESCs and wild type mESCs in morphology and pluripotent capability under the pluripotent state. In brief, these data indicated Clock did not influence the maintaining of pluripotent state. However, they exhibited decreased proliferation and increased apoptosis. Furthermore, the biological rhythms failed to develop in Clock knockout mESCs after spontaneous differentiation, which indicated that there was no compensational factor in most peripheral tissues as described in mice models before （DeBruyne et ah, 2007b）. After spontaneous differentiation, loss of CLOCK protein due to Clock gene silencing induced spontaneous differentiation of mESCs, indicating an exit from the pluripotent state, or its differentiating ability. Our findings indicate that the core circadian gene Clock may be essential during normal mESCs differentiation by regulating mESCs proliferation, apoptosis and activity.展开更多
The oriental armyworm,Mythimna separata,is a major long-distance migratory insect pest of grain crops in China and other Asian countries.Migratory flights and reproductive behavior usually occur at night,regulated by ...The oriental armyworm,Mythimna separata,is a major long-distance migratory insect pest of grain crops in China and other Asian countries.Migratory flights and reproductive behavior usually occur at night,regulated by a circadian rhythm.However,knowledge about the linkages between adult flight,reproduction,and clock genes is still incomplete.To fill this important gap in our knowledge,a clock gene(designated Msper)was identified and phylogenetic analysis indicated that the encoded protein(MsPER)was highly similar to PER proteins from other insect species.Quantitative RT-PCR assays demonstrated that significantly different spatiotemporal and circadian rhythmic accumulations of mRNA encoding MsPER occurred during development under steady 14 h:10 h light:dark conditions.The highest mRNA accumulation occurred in adult antennae and the lowest in larvae.Msper was expressed rhythmically in adult antennae,relatively less in photophase and more entering scotophase.Injecting small interference RNA(siRNA)into adult heads effectively knocked down Msper mRNA levels within 72 h.Most siRNA-injected adults reduced their evening flight activity significantly and did not exhibit a normal evening peak of flight activity.They also failed to mate and lay eggs within 72 h.Adult mating behavior was restored to control levels by 72 h post injection.We infer that Msper is a prominent clock gene that acts in regulating adult migratory flight and mating behaviors of M.separata.Because of its influence on migration and mating,Msper may be a valuable gene to target for effective management of this migratory insect.展开更多
基金supported by grants from the National Natural Science Foundation of China(N0.82474525 and No.82074444)the Hunan Provincial Natural Outstanding Young People Science Foundation(2023JJ10032)the Hunan Province Health and High-Level Talent Medical Academic Leader Training Plan(20240304051).
文摘The circadian clock is an important internal time regulatory system for a range of physiological and behavioral rhythms within living organisms.Testosterone,as one of the most critical sex hormones,is essential for the development of the reproductive system,maintenance of reproductive function,and the overall health of males.The secretion of testosterone in mammals is characterized by distinct circadian rhythms and is closely associated with the regulation of circadian clock genes.Here we review the central and peripheral regulatory mechanisms underlying the influence of circadian clock genes upon testosterone synthesis.We also examined the specific effects of these genes on the occurrence,development,and treatment of common male diseases,including late-onset hypogonadism,erectile dysfunction,male infertility,and prostate cancer.
文摘Clock genes create a complicated molecular time-keeping system consisting of multiple positive and negative feedback loops at transcriptional and translational levels. This circadian system coordinates and regulates multiple cellular procedures implicated in cancer development such as metabolism, cell cycle and DNA damage response. Recent data support that molecules such as CLOCK1, BMAL1 and PER and CRY proteins have various effects on c-Myc/p21 and Wnt/β-catenin pathways and influence multiple steps of DNA damage response playing a critical role in the preservation of genomic integrity in normal and cancer cells. Notably, all these events have already been related to the development and progression of colorectal cancer (CRC). Recent data highlight critical correlations between clock genes’ expression and pathogenesis, progression, aggressiveness and prognosis of CRC. Increased expression of positive regulators of this circadian system such as BMAL1 has been related to decrease overall survival while decreased expression of negative regulators such as PER2 and PER3 is connected with poorer differentiation, increased aggressiveness and worse prognosis. The implications of these molecules in DNA repair systems explain their involvement in the development of CRC but at the same time provide us with novel targets for modern therapeutic approaches for patients with advanced CRC.
基金supported by grants from the Department of Public Health of Hubei Province of China (No. 2012Z-B08)the Health Bureau of Wuhan City of China (No. WX12C10)
文摘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.
文摘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.
基金This work was supported by the National Natural Science Foundation of China(Nos.81901430 and 81871835)the Guangdong Provincial Natural Science Foundation of China(No.2022A1515010379)+1 种基金the Innovation Project from Department of Education of Guangdong Province(No.2021KTSCX 055)the Shanghai Frontiers Science Research Base of Exercise and Metabolic Health,and the Shanghai Key Laboratory for Human Athletic Ability Development and Support(Shanghai University of Sport)(No.11DZ2261100),China.
文摘Mammalian bone is constantly metabolized from the embryonic stage,and the maintenance of bone health depends on the dynamic balance between bone resorption and bone formation,mediated by osteoclasts and osteoblasts.It is widely recognized that circadian clock genes can regulate bone metabolism.In recent years,the regulation of bone metabolism by non-coding RNAs has become a hotspot of research.MicroRNAs can participate in bone catabolism and anabolism by targeting key factors related to bone metabolism,including circadian clock genes.However,research in this field has been conducted only in recent years and the mechanisms involved are not yet well established.Recent studies have focused on how to target circadian clock genes to treat some diseases,such as autoimmune diseases,but few have focused on the co-regulation of circadian clock genes and microRNAs in bone metabolic diseases.Therefore,in this paper we review the progress of research on the co-regulation of bone metabolism by circadian clock genes and microRNAs,aiming to provide new ideas for the prevention and treatment of bone metabolic diseases such as osteoporosis.
文摘Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were randomized equally into control group and heat stress group.After exposure to 32℃for 2 weeks in the latter group,the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry.In the cell experiments,cultured rat thoracic aortic endothelial cells(RTAECs)were incubated at 40℃for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA(si-Bmal1)or a negative sequence.In both rat thoracic aorta and RTAECs,the expressions of Bmal1,the cell cycle proteins CDK1,CDK4,CDK6,and cyclin B1,and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting.TUNEL staining was used to detect cell apoptosis in rat thoracic aorta,and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry.Results Compared with the control rats,the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1,cyclin B1 and CDK1 in the thoracic aorta(P<0.05).In cultured RTAECs,heat stress caused significant increase of Bmal1,cyclin B1 and CDK1 protein expression levels,which were obviously lowered in cells with prior si-Bmal1 transfection.Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2.Conclusion Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells,which can be partly alleviated by suppressing Bmal1 expression.
基金Supported by the National Natural Science Foundation of China(No.31402305)the Educational Commission of Sichuan Province of China(No.14ZA0249)+1 种基金the Key Technologies R&D Program of Neijiang,Sichuan,China(No.12108)the College Students’ Scientific Research Project of Neijiang Normal University(Nos.13NSD-66,13NSD-77)
文摘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.
基金supported by the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2019ZT08N291)the Science and Technology Program of Guangzhou,China(2023A04J0760)the Guangdong Basic and Applied Basic Research Foundation(2024A1515030058).
文摘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.
基金Supported by American Diabetes AssociationAmerican Heart Association+3 种基金NIH NIEHSNIH NIANIH NINDSand NIH ARRA.
文摘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.
基金supported by the following funding:National Natural Science Foundations of China(82002888,82272899 and 82370974)Sichuan Science and Technology Program(2022YFS0207 and 2023YFS0127)+1 种基金Scientific Research Foundation,WestChinaHospital of Stomatology SichuanUniversity(RCDWJS2021-8)the CAMS Innovation Fund for Medical Sciences(CIFMS,2019-I2M-5-004).
文摘This review explores the pivotal role of circadian rhythm regulators,particularly the PER genes,in Oral Squamous Cell Carcinoma(OSCC).As key constituents of the biological clock,PERs exhibit a downregulated expression pattern in OSCC,and the expression levels of PERs in OSCC patients are correlated with a favorable prognosis.PERs impact the occurrence and development of OSCC through multiple pathways.In the regulation of cell proliferation,they can function not only through cell cycle regultion but also via metabolic pathways.For example,PER1 can interact with receptors for activated C kinase 1(RACK1)and phosphatidylinositol 3-kinase(PI3K)through its PAS domain to inhibit glycolysis and thereby reduce cell proliferation.Regarding the regulation of cell death,PERs mediate various types of cell death in OSCC cells,such as p53-dependent apoptosis,protein kinase B(AKT)/mammalian target of rapamycin(mTOR)dependent autophagy,or hypoxia-inducible factor l-alpha(HIF-1a)mediated ferroptosis.In regulating epithelia-mesenchymal transition(EMT),PERs can lead to the downregulation of EMT related genes,such as zinc finger E-box binding homeobox 1/2(ZEBI/2),twist family BHLH transcription factor 1/2(TWIST1/2),and Vimentin,thereby influencing the migration and invasion capabilities of OSCC cells.In tumor angiogenesis,PERs exert regulatory effects on related factors,such as methionyl aminopeptidase 2(MetAP2)and vascular endothelial growth factor(VEGF).In the tumor immune microenvironment,PERs can inhibit the inhibitor of kappa B kinase(IKK)/nuclear factor kappa B(NF-kB)pathway and programmed cell death ligand 1(PD-L1)expression,thereby enhancing the cytotoxic effect of CD8+T cells on OSCC cells.In-depth studies focusing on elucidating the precise regulatory mechanisms of PERs can facilitate the development of therapeutic strategies targeting PERs,including restoration of PERs expression/activity,targeting PERs-regulated pathways,combination therapies,and chronotherapy.These furnish a theoretical foundation for formulating individualized treatment plans to achieve precise treatment for patients with OSCC.
基金Supported by National Natural Science Foundation of China,No.82270634.
文摘As one of the most prevalent malignant tumors,hepatocellular carcinoma(HCC)represents a major global public health burden.Traditionally,HCC pathogenesis has been attributed to chronic liver diseases(viral hepatitis,cirrhosis)and aflatoxin exposure.However,with evolving lifestyles and environmental changes,sleep disorders have become increasingly prevalent.Emerging evidence suggest that sleep disorders may contribute to hepatocarcinogenesis through multiple mechanisms,including immunity environment disorder,oxidative stress,metabolic dysregulation,disruption of gut microbiota,and circadian rhythm disruption,thereby influencing disease progression and patient prognosis.This review summarizes epidemiological evidence on the relationship between sleep disorders and HCC incidence,explores the underlying mechanisms through which sleep disorders contribute to HCC,and discusses clinical challenges and potential intervention strategies.Our objective is to provide novel insights into HCC prevention and therapeutic approaches.
文摘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.
基金financial support of the European Union(FP7-PEOPLE-IEF,03197 Obesity and Light)the Netherlands Organization for Scientific Research(VIDI/864.09.005 and ASPASIA/015.006.018)
文摘A growing body of evidence indicates that exposure to environmental chemicals can contribute to the etiology of obesity by inappropriately stimulating adipogenesis as well as perturbing lipid metabolism and energy balance. One potential mechanism by which chemical exposure can influence lipid metabolism is through disturbance of circadian rhythms, endogenously-driven cycles of roughly 24 hr in length that coordinate biochemical, physiological, and behavioral processes in all organisms. Here we show for the first time that exposure to endocrine disrupting compounds（EDCs）, including the pesticide tributyltin, two commercial flame retardants, and a UV-filter chemical found in sunscreens,can perturb both circadian clocks and lipid metabolism in vertebrates. Exposure of developing zebrafish to EDCs affects core clock activity and leads to a remarkable increase in lipid accumulation that is reminiscent of the effects observed for longdaysin, a known disruptor of circadian rhythms. Our data reveal a novel obesogenic mechanism of action for environmental chemicals, an observation which warrants further research. Because circadian clocks regulate a wide variety of physiological processes, identification of environmental chemicals capable of perturbing these systems may provide important insights into the development of environmentally-induced metabolic disease.
基金supported by the National Natural Science Foundation of China(Nos.21876135,22036001,22076146 and 21876136).
文摘The prevalence of artificial lights not only improves the lighting conditions for modern society,but also poses kinds of health threats to human health.Although there are regulations and standards concerning light pollution,few of them are based on the potential contribution of improper lighting to diseases.Therefore,a better understanding of the health threats induced by light pollution may promote risk assessment and better regulation of artificial lights,thereby a healthy lighting environment.This review is based on a careful collection of the latest papers from 2018 to 2022 about the health threats of light pollution,both epidemiologically and experimentally.In addition to summing up the novel associations of light pollution with obesity,mental disorders,cancer,etc.,we highlight the toxicological mechanism of light pollution via circadian disruption,since light pollution directly interferes with the natural light-dark cycles,and damages the circadian photoentrainment of organisms.And by reviewing the alternations of clock genes and disturbance of melatonin homeostasis induced by artificial lights,we aim to excavate the profound impacts of light pollution based on accumulating studies,thus providing perspectives for future research and guiding relevant regulations and standards.
基金supported by grants PID2020-115156GB-I00 and PID2023-146573NB-I00funded by Ministerio de Ciencia e Innovacion/Agencia Estatal de Investigacion,Spain/10.13039/501100011033.
文摘Daily cycles due to Earth’s rotation have led to the evolution of circadian clocks that allow the anticipation of the physiological responses of almost all living organisms to predictable environmental conditions.In eukaryotes,circadian oscillations rely on endogenous transcriptional-translational feedback loops,autoregulatory mechanisms that ensure the precise control of the clock genes.
文摘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.
基金supported by the National Natural Science Foundation of China(No.22274072)。
文摘The CRISPR-Cas13 systems have opened a new avenue for RNA detection due to their exceptional programmable collateral activity against ssRNA.However,most high-performance Cas13-based RNA sensors still suffer from some drawbacks because of the tradeoffs between readout device complexity and analytical sensitivity,which can limit their viability at the point-of-care(POC).To overcome these shortcomings,we herein report a novel target-responsive POC platform for translating RNA detection into a glucose test.Specifically,this platform combines the advantages of three techniques:a hybrid Cas13a/Cas12a system for both RNA recognition with single-base resolution and cascade enzymatic amplification,a self-sustainable catalytic nucleic acid circuit(SCC)with embedded uracil-base and poly-T bulges for Cas13a-and Cas12amediated collateral cleavage,respectively,and a portable glucose meter(PGM)for simple signal readout.The incorporation of an engineered ssDNA–invertase conjugate in SCC led to RNA-to-glucose signal transduction through the hydrolysis of sucrose to glucose.By targeting a 20-nt conserved region of BMAL1 mRNA(mBMAL1),a key circadian clock gene,we demonstrate that SCC can serve as an excellent CRISPR reporter,enabling the direct detection of unamplified mBMAL1 as low as 0.864 fM concurrently with good discrimination ability for single-base mismatch.More importantly,this integrated platform was successfully applied for POC diagnosis of mBMAL1 from different cell lysates,with results that strongly correlate with RT-PCR.Given its wide adaptability,we anticipate that such a CRISPR-SCC system can be easily modified to quantify other RNA biomarkers associated with circadian rhythm.
基金This work was supported by the National Natural Science Foundation of China(NSFC,31270457,30800129 to Z.X.),NSFC(31971413)the Natural Science Foundation of Hebei Province(NSFHB,C2020205038 to D.L).
文摘Hibernation is one of the fundamental strategies in response to cold environmental temperatures.During hibernation,the endocrine and circadian systems ensure minimal expenditure of energy for survival.The circadian rhythms of key hormones,melatonin(MT),corticosterone(CORT),triiodothyronine(T3),and thyroxine(T4),and the underlying molecular regulatory mechanisms of hibernation have been well determined in mammals but not in ectotherms.Here,a terrestrial hibernating species,Asiatic toad(Bufo gargarizans),was employed to investigate the plasma CORT,MT,T3,and T4;and the retina,brain,and liver mRNA expression of the core clock genes,including circadian locomotor output cycles kaput(Clock),brain and muscle ARNT-like 1(Bmal1),cryptochrome(Cry)1 and 2,and period(Per)1 and 2,at 7-time points over a 24-h period under acute cold(1 day at 4℃),and hibernation(45 days at 4℃).Our results showed that the circadian rhythms of the core clock genes were rather unaffected by acute cold exposure in the retina,unlike the brain and liver.In contrast,during hibernation,the liver clock genes displayed significant circadian oscillations,while those in the retina and brain stopped ticking.Furthermore,plasma CORT expressed circadian oscillations in both groups,and T3 in acute cold exposure group,whereas T4 and MT did not.Our results reveal that the plasma CORT and the liver sustain rhythmicity when the brain was not,indicating that the liver clock along with the adrenal clock synergistically maintains the metabolic requirements to ensure basic survival in hibernating Asiatic toads.
文摘Biological rhythms controlled by the circadian clock are absent in embryonic stem cells （ESCs）. However, they start to develop during the differentiation of pluripotent ESCs to downstream cells. Conversely, biological rhythms in adult somatic cells disappear when they are reprogrammed into induced pluripotent stem cells （iPSCs）. These studies indicated that the development of biological rhythms in ESCs might be closely associated with the maintenance and differentiation of ESCs. The core circadian gene Clock is essential for regulation of biological rhythms. Its role in the development of biological rhythms of ESCs is totally unknown. Here, we used CRISPR/CAS9-mediated genetic editing techniques, to completely knock out the Clock expression in mouse ESCs. By AP, teratoma formation, quantitative real-time PCR and Immunofluorescent staining, we did not find any dif- ference between Clock knockout mESCs and wild type mESCs in morphology and pluripotent capability under the pluripotent state. In brief, these data indicated Clock did not influence the maintaining of pluripotent state. However, they exhibited decreased proliferation and increased apoptosis. Furthermore, the biological rhythms failed to develop in Clock knockout mESCs after spontaneous differentiation, which indicated that there was no compensational factor in most peripheral tissues as described in mice models before （DeBruyne et ah, 2007b）. After spontaneous differentiation, loss of CLOCK protein due to Clock gene silencing induced spontaneous differentiation of mESCs, indicating an exit from the pluripotent state, or its differentiating ability. Our findings indicate that the core circadian gene Clock may be essential during normal mESCs differentiation by regulating mESCs proliferation, apoptosis and activity.
基金the National Natural Science Foundation of China(No.32072420,31871951,31672019)China Agriculture Research System of MOF and MARA(CARS-22)the National Key Research and Development Program of China(2017YFD0201802,2017YFD0201701).
文摘The oriental armyworm,Mythimna separata,is a major long-distance migratory insect pest of grain crops in China and other Asian countries.Migratory flights and reproductive behavior usually occur at night,regulated by a circadian rhythm.However,knowledge about the linkages between adult flight,reproduction,and clock genes is still incomplete.To fill this important gap in our knowledge,a clock gene(designated Msper)was identified and phylogenetic analysis indicated that the encoded protein(MsPER)was highly similar to PER proteins from other insect species.Quantitative RT-PCR assays demonstrated that significantly different spatiotemporal and circadian rhythmic accumulations of mRNA encoding MsPER occurred during development under steady 14 h:10 h light:dark conditions.The highest mRNA accumulation occurred in adult antennae and the lowest in larvae.Msper was expressed rhythmically in adult antennae,relatively less in photophase and more entering scotophase.Injecting small interference RNA(siRNA)into adult heads effectively knocked down Msper mRNA levels within 72 h.Most siRNA-injected adults reduced their evening flight activity significantly and did not exhibit a normal evening peak of flight activity.They also failed to mate and lay eggs within 72 h.Adult mating behavior was restored to control levels by 72 h post injection.We infer that Msper is a prominent clock gene that acts in regulating adult migratory flight and mating behaviors of M.separata.Because of its influence on migration and mating,Msper may be a valuable gene to target for effective management of this migratory insect.
