In our previous report, PERK/NRF2/CX43/StAR/progesterone pathway activation in ovarian granulosa cells was shown to mediate cold-induced female reproductive disorders. However, how PERK is activated by low temperature remained unclear. In the present study, we found that the circadian protein E4BP4 was significantly upregulated in ovarian granulosa cells following exposure to cold or isoproterenol (ISO), a non-selective β-adrenergic receptor agonist that pharmacologically activates β-adrenergic signaling, a key component of the cold stress response. Mechanistically, E4BP4 interacted with PERK and was required for PERK activation and subsequent NRF2/CX43/StAR signaling, leading to increased progesterone secretion. Interestingly, NRF2 also acted as a transcriptional activator of E4BP4 under ISO treatment, and blocking PERK or NRF2 expression attenuated ISO-induced E4BP4 accumulation, suggesting a positive feedback loop involving PERK/NRF2/E4BP4. Collectively, these findings identify E4BP4 as a cold-responsive circadian protein that interacts with PERK and may contribute to cold-induced reproductive disorders via a bidirectional E4BP4-PERK feedback loop.

Sleep is critical for maintaining overall health. Insufficient sleep duration and poor sleep quality are associated with various physical and mental health risks and chronic diseases. To date, plenty of epidemiological research has shown that sleep disorders are associated with the risk of obesity, which is usually featured by the expansion of adipose tissue. However, the underlying mechanism of increased fat accumulation upon sleep disorders remains unclear. Here we demonstrated that sleep deprivation (SD) caused triglycerides (TG) accumulation in the visceral white adipose tissue (vWAT), accompanied by a remarkable decrease in the expression of adipose triglyceride lipase (ATGL) and other two rate-limiting lipolytic enzymes. Due to the key role of ATGL in initiating and controlling lipolysis, we focused on investigating the signaling pathway leading to attenuated ATGL expression in vWAT upon SD in the following study. We observed that ATGL downregulation resulted from the suppression of ATGL transcription, which was mediated by the reduction of the transcriptional factor FOXO1 and its upstream regulator SIRT1 expression in vWAT after SD. Furthermore, impairment of SIRT1/FOXO1/ATGL pathway activation and lipolysis induced by SIRT1 inhibitor EX527 in the 3 T3-L1 adipocytes were efficiently rescued by the SIRT1 activator resveratrol. Most notably, resveratrol administration in SD mice revitalized the SIRT1/FOXO1/ATGL pathway activation and lipid mobilization in vWAT. These findings suggest that targeting the SIRT1/FOXO1/ATGL pathway may offer a promising strategy to mitigate fat accumulation in vWAT and reduce obesity risk associated with sleep disorders.

Ambient air temperature is a key factor affecting human health. Female reproductive disorders are representative health risk events under low temperature. However, the mechanism involving in cold-induced female reproductive disorders remains largely unknown. Female mice were intermittently exposed to cold conditions (4 °C) to address the health risk of low temperature on female reproductive system. Primary granulosa cells (GCs) were prepared and cultured under low temperature (35 °C) or exposed to β3-adrenoreceptor agonist, isoproterenol, to mimic the condition of cold exposure. Western-blot, RT-PCR, co-IP, ELISA, pharmacological inhibition or siRNA-mediated knockdown of target gene were performed to investigate the possible role of hormones, gap conjunction proteins, and ER stress sensor protein in regulating female reproductive disorders under cold exposure. Cold exposure induced estrous cycle disorder and follicular dysplasia in female mice, accompanying with abnormal upregulation of progesterone and its synthetic rate-limiting enzyme, StAR, in the ovarian granulosa cells. Under the same conditions, an increase in connexin 43 (CX43) expressions in the GCs was also observed, which contributed to elevated progesterone levels in the ovary. Moreover, ER stress sensor protein, PERK, was activated in the ovarian GCs after cold exposure, leading to the upregulation of downstream NRF2-dependent CX43 transcription and aberrant increase in progesterone synthesis. Most importantly, blocking PERK expression in vivo significantly inhibited NRF2/CX43/StAR/progesterone pathway activation in the ovary and efficiently rescued the prolongation of estrous cycle and the increase in follicular atresia of the female mice induced by cold stress. We have elucidated the mechanism of ovarian PERK/NRF2/CX43/StAR/progesterone pathway activation in mediating female reproductive disorder under cold exposure. Targeting PERK might be helpful for maintaining female reproductive health under cold conditions.

Sleep deprivation (SD) weakens the immune system and leads to increased susceptibility to infectious or inflammatory diseases. However, it is still unclear how SD affects humoral immunity. In the present study, sleep disturbance was conducted using an sleep deprivation instrument, and the bacterial endotoxin lipopolysaccharide (LPS) was used to activate the immune response. It was found that SD-pretreatment reduced LPS-induced IgG2b+ B cells and IgG2b isotype antibody production in lymphocytes of spleen. And, SD-pretreatment decreased the proportion of CD4+T cells, production of CD4+T cells derived TGF-β1 and its contribution in helping IgG2b production. Additionally, BMAL1 and CLOCK were selectively up-regulated in lymphocytes after SD. Importantly, BMAL1 and CLOCK deficiency contributed to TGF-β1 expression and production of IgG2b+ B cells. Thus, our results provide a novel insight to explain the involvement of BMAL1 and CLOCK under SD stress condition, and their roles in inhibiting TGF-β1 expression and contributing to reduction of LPS induced IgG2b production.

High altitudes or exposure to hypoxia leads to female reproductive disorders. Circadian clocks are intrinsic time-tracking systems that enable organisms to adapt to the Earth’s 24-h light/dark cycle, which can be entrained by other environmental stimuli to regulate physiological and pathological responses. In this study, we focused on whether ovarian circadian clock proteins were involved in regulating female reproductive dysfunction under hypoxic conditions. Hypobaric hypoxia was found to induce a significantly prolonged estrous cycle in female mice, accompanied by follicular atresia, pituitary/ovarian hormone synthesis disorder, and decreased LHCGR expression in the ovaries. Under the same conditions, the levels of the ovarian circadian clock proteins, CLOCK and BMAL1, were suppressed, whereas E4BP4 levels were upregulated. Results from granulosa cells (GCs) further demonstrated that CLOCK: BMAL1 and E4BP4 function as transcriptional activators and repressors of LHCGR in ovarian GCs, respectively, whose responses were mediated by HIF1ɑ-dependent (E4BP4 upregulation) and ɑ-independent (CLOCK and BMAL1 downregulation) manners. The LHCGR agonist was shown to efficiently recover the impairment of ovulation-related gene ( EREG and PGR ) expression in GCs induced by hypoxia. We conclude that hypoxia exposure causes dysregulation of ovarian circadian clock protein (CLOCK, BMAL1, and E4BP4) expression, which mediates female reproductive dysfunction by impairing LHCGR-dependent signaling events. Adjusting the timing system or recovering the LHCGR level in the ovaries may be helpful in overcoming female reproductive disorders occurring in the highlands.

目的 探讨低温暴露对卵巢组织炎性因子表达的影响及相关分子机制.方法 将6～8周龄雌性小鼠随机分为对照组以及低温暴露组,暴露后取卵巢组织,通过RT?PCR方法检测炎性因子表达水平,Western印迹法检测炎性反应相关蛋白的表达变化及活化情况.体外培养SKOV3细胞,进行温和冷暴露(35℃),通过RT?PCR和Western印迹法检测炎性因子和炎性反应相关蛋白的表达水平及活化情况.结果 低温暴露后卵巢的组织局部出现肿瘤坏死因子(TNF?α)表达水平的显著上调,炎性转录因子NF?κB p65活化.体外培养的SKOV3卵巢癌细胞经温和冷刺激后,同样能观察到TNF?α表达水平的显著上调和炎性转录因子NF?κB p65的诱导活化;在SKOV3细胞中转染NF?κB p65 siRNA后,可显著抑制TNF?α的诱导表达.结论 低温暴露通过诱导卵巢组织NF?κB p65活化介导炎性因子TNF?α上调及炎症反应.

目的 探讨生物钟基因per2对72 h睡眠剥夺(SD)前后脾淋巴细胞功能的影响.方法 将C57小鼠随机分为野生型小鼠对照组(WT)和野生型小鼠睡眠剥夺组(WT-SD);per2基因敲除小鼠(per2-/-)随机分为per2基因敲除小鼠对照组(per2-/-)和per2基因敲除小鼠睡眠剥夺组(per2-/--SD).SD组小鼠使用睡眠剥夺仪进行连续睡眠剥夺72 h.小鼠麻醉后摘脾,使用淋巴细胞分离液分离获得淋巴细胞悬液,利用流式细胞术检测各组别CD4+T、CD8+T、CD3+T以及B220+B比例变化,并通过脂多糖(LPS)刺激3 d体外培养进行流式染色检测上述各淋巴细胞的比例变化,同时使用CCK-8法检测各组小鼠脾B细胞的增殖情况.结果 与WT组小鼠相比,per2-/-组小鼠脾CD4+T、CD8+T以及B220+B细胞比例无明显改变;在进一步的睡眠剥夺实验中发现,per2基因敲除影响T细胞,尤其是CD8+T的组成变化.在LPS刺激实验中,与WT组相比,SD组小鼠脾淋巴细胞增殖更加明显,且与WT-SD组相比,per2-/--SD组B220+B细胞比例增加.同样睡眠剥夺应激条件下,小鼠脾淋巴细胞增殖无明显变化,但与WT-SD组相比,per2-/--SD组脾B细胞降低同时对应T细胞比例升高.结论 per2对脾淋巴细胞的组成影响较小,但在一定程度上参与调节睡眠剥夺后B淋巴细胞对LPS的增殖反应.

目的 探讨急性睡眠剥夺(SD)应激条件下大鼠肝组织胆汁酸转运体昼夜振荡表达的变化规律.方法将大鼠随机分为对照组和实验组.实验组大鼠使用SD仪在24 h昼夜周期内进行急性SD.分离血清后,利用胆汁酸检测试剂盒分析血清中总胆汁酸水平;取肝组织,加入TRIzol试剂后利用组织匀浆仪裂解细胞,通过RT-PCR方法检测肝组织中胆汁酸转运体振荡表达变化.结果与对照组相比,在SD 16 h后总胆汁酸水平显著升高.SD应激条件下,肝组织中胆汁酸转运体钠离子-牛磺胆酸协同转运蛋白(NTCP)和有机阴离子转运多肽(OATP)昼夜振荡变化规律消失,表达水平呈现降低变化;胆汁酸转运体胆盐输出泵(BSEP)和多药耐药相关蛋白2(MRP2)昼夜振荡表达受SD影响相对较小,但MRP2表达峰值呈现一定降低.结论急性SD应激条件可能通过影响胆汁酸转运体NTCP和OATP的振荡表达导致血清总胆汁酸水平异常升高.

Sleep loss leads to a spectrum of mood disorders such as anxiety disorders, bipolar disorder and depression in many individuals. However, the underlying mechanisms are largely unknown. In this study, sleep-disturbed animals were tested for anxiety and depressive behaviors. We then studied the effects of SD on hypothalamic-pituitary-adrenal (HPA) axis function by measuring serum and CSF levels of corticosterone (CORT), and at the end of the experiment, brains were collected to measure the circadian oscillations of clock genes expression in the hypothalamus, glial cell activation and inflammatory cytokine alterations. Our results indicated that SD for 3 days resulted in anxiety- and depressive-like behaviors. SD exaggerated cortisol response to HPA axis, significantly altered the circadian oscillations of clock genes, decreased the expression of tight junction protein ZO-1 and Claudin 5 and increased the number of GFAP-positive cells and Iba-1-positive cells and caused subsequent elevation of pro-inflammatory cytokines IL-6, IL-1β and TNFα. These findings demonstrated that SD for 3 days induced anxiety- and depression-like behaviors in rats in company with altering the circadian oscillations of clock genes and inducing neuroinflammation, indicating the underlying mechanism of sleep loss induced neuronal dysfunction.

目的 探究热应激致肝炎症损伤的分子机制.方法 雌性SD大鼠随机分为对照组和热应激组,38℃暴露建立热应激动物模型,每天暴露2 h,连续3 d,分离肝组织;体外培养的L-02细胞分为对照组、热应激组、热应激+二甲基亚砜(DMSO)组及热应激+白藜芦醇组(100μmol/L),采用5％CO2,41℃暴露建立热应激细胞模型,药物组及溶剂对照组提前给予100μmol/L白藜芦醇或DMSO预处理2 h,再进行热应激暴露,分别收取细胞;以上收取的肝组织及细胞均进行NOD样受体热蛋白结构域相关蛋白3(NLRP3)、胱天蛋白酶-1(caspase-1)蛋白表达水平及白细胞介素-1β(IL-1β)、IL-6 mRNA表达水平检测.结果 ①与对照组相比,热应激可导致肝NLRP3炎症小体的激活,促进caspase-1将IL-1β切割为活性形式,进而导致下游靶基因IL-6的表达上调.敲低L-02细胞中NLRP3表达可显著抑制炎症小体的激活及下游炎症因子级联表达反应的发生;②白藜芦醇可通过抑制NLRP3的表达从而拮抗热应激所致肝细胞炎症因子诱导表达效应.结论 热应激通过NLRP3/IL-1β/IL-6途径诱导肝脏炎症损伤,白藜芦醇能缓解以上炎症损伤反应,在热应激损伤防护中具有潜在应用前景.

Background: Sleep loss leads to a spectrum of mood disorders such as anxiety, cognitive dysfunction and motor coordination impairment in many individuals. However, the underlying mechanisms are largely unknown. Methods: In this study, we examined the effects of sleep deprivation (SD) on depression and the mechanism by subjecting rats to a slowly rotating platform for 3 days to mimic the process of sleep loss. Sleep-deprived animals were tested behaviorally for anxiety- and depressive-like behaviors. We further studied the effects of SD on hypothalamic-pituitary-adrenal (HPA) axis activity, and at the end of the experiment, brains were collected to measure the circadian clock genes expression in the hypothalamus, glial cell activation and inflammatory cytokine alterations. Results: Our results indicated that SD for 3 days resulted in anxiety- and depressive-like behaviors. SD exaggerated cortisol response to HPA axis, significantly altered the mRNA profile of circadian clock genes, and induced neuroinflammation by increasing the expression of glial cell markers, including the microglial marker ionized calcium-binding adapter molecule 1 (Iba1) and the astroglial marker glial fibrillary acidic protein (GFAP). The expression of M1 and M2 microglial markers (Arg-1 and CD206, respectively) and pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) were increased in the brain. Conclusion: These results indicated that SD for 3 days induced anxiety- and depression-like behaviors in rats by impairing the regulation of circadian clock genes and inducing neuroinflammation, ultimately resulting in brain injury.

地球的自转产生了以24 h为周期的昼夜节律,因此生物的生理过程和行为活动大都呈现一个近似24 h的周期节律改变,以适应环境的不断变化.昼夜节律在整体水平是一个系统性的调控,它的产生、维持和调控依赖于细胞内生物钟基因的震荡型转录翻译负反馈环路.研究表明,生物钟在卵巢动情周期和生殖系统发育过程中发挥重要作用.本篇综述主要阐述了自卵巢生物钟发现后的种种研究成果,包括卵巢生物钟对类固醇激素生成及排卵的影响,生物钟基因对生育能力的影响,以及生物钟调控与女性生殖系统疾病的相关性.

Disturbed sleep is closely associated with an increased risk of metabolic diseases. However, the underlying mechanisms of circadian clock genes linking sleep and lipid profile abnormalities have not been fully elucidated. This study aimed to explore the important role of the circadian clock in regulating impaired cholesterol metabolism at an early stage of sleep deprivation (SD). Sleep disturbance was conducted using an SD instrument. Our results showed that SD increased the serum cholesterol levels. Concentrations of serum leptin and resistin were much lower after SD, but other metabolic hormone concentrations (adiponectin, glucagon, insulin, thyroxine, norepinephrine, and epinephrine) were unchanged before and after SD. Warning signs of cardiovascular diseases [decreased high density lipoprotein (HDL)-cholesterol and increased corticosterone and 8-hydroxyguanosine levels] and hepatic cholestasis (elevated total bile acids and bilirubin levels) were observed after SD. Cholesterol accumulation was also observed in the liver after SD. The expression levels of HMGCR, the critical enzyme for cholesterol synthesis, remained unchanged in the liver. However, the expression levels of liver CYP7A1, the enzyme responsible for the conversion of cholesterol into bile acids, significantly reduced after SD. Furthermore, expression of NR1D1, a circadian oscillator and transcriptional regulator of CYP7A1, strikingly decreased after SD. Moreover, NR1D1 deficiency decreased liver CYP7A1 levels, and SD could exacerbate the reduction of CYP7A1 expression in NR1D1−/− mouse livers. Additionally, NR1D1 deficiency could further increase serum cholesterol levels under SD. These results suggest that sleep disturbance can induce increased serum cholesterol levels and liver cholesterol accumulation by NR1D1 mediated CYP7A1 inhibition.

在各种组织和器官中都存在允许相邻细胞的胞质区之间直接通讯的间隙连接,它们在广泛的生理过程中起关键作用.间隙连接是细胞间通道,由间隙连接蛋白组成,其中间隙连接蛋白43(Cx43)在各组织器官中广泛表达.研究发现细胞间隙连接通讯会受到冷热刺激的影响,并与Cx43表达相关.本篇综述主要介绍Cx43转录与翻译水平的调控以及它的降解途径,并对冷热刺激后Cx43表达变化的作用机制进行概述.

Two catalytic subunits of the IKK complex, IKKα and IKKβ, trigger NF-κB activation as well as NF-κB-independent signaling events under both physiological and pathological conditions. Here we identified the NF-κB-unrelated cytoprotective function of IKKα in promoting autophagy by triggering p53 transactivation and upregulation of its downstream autophagic mediator, DRAM1, in the arsenite-treated hepatoma cells, which responses depended on IKKα kinase activity. Furthermore, IKKα triggered p53/DRAM1-dependent autophagy by inducing CHK1 activation and CHK1/p53 interaction. Interestingly, after provoking autophagy, IKKα could be specifically recognized by the autophagic machinery via directly binding with LC3B, resulting in selective degradation of IKKα by autophagy. Unexpectedly, the selectivity of autophagic sequestration towards IKKα was mediated by novel mechanism independent of the classical LC3-interacting regions (LIRs) within IKKα, while C-terminal arm of LIR was involved in mediating IKKα/LC3B interaction. Taken together, we conclude that IKKα attenuates arsenite-induced apoptosis by inducing p53-dependent autophagy, and then selective feedback degradation of IKKα by autophagy contributes to the cytotoxic response induced by arsenite.