Circadian rhythms and fertility

Circadian rhythms impact on a wide range of physiological systems and this impact extends to fertility, such that disruptions to timing systems can impact upon reproductive capacity. This is highlighted most obviously in mutant mouse models whereby deletion or mutation of single genes results not only in disrupted circadian rhythmicity, but also compromised male and female reproductive function. In this review, we discuss the presence of circadian clocks in female and male reproductive tissues and the role these clocks play in the generation of oestrus cycles, ovulation, sperm generation, implantation and the maintenance of pregnancy. Given the increased incidence of shiftwork and international travel which disrupt circadian rhythmicity, and the increasing prevalence of reproductive technologies whereby early embryo development occurs without external time cues, it is important for us to consider the role of circadian rhythms in fertility.     

Circadian clock signals in the adrenal cortex

Circadian secretion of steroid hormones by the adrenal cortex is required to maintain whole body homeostasis and to adequately respond to or anticipate environmental changes. The richly vascularized zona glomerulosa (ZG) cells in the pericapsular region regulate osmotic balance of body fluid by secreting mineralocorticoids responding to circulating bioactive substances, and more medially located zona fasciculata (ZF) cells regulate energy supply and consumption by secreting glucocorticoids under neuronal and hormonal regulation. The circadian clock regulates both steroidogenic pathways: the clock within the ZG regulates mineralocorticoid production via controlling rate-limiting synthetic enzymes, and the ZF secretes glucocorticoid hormones into the systemic circulation under the control of central clock in the suprachiasmatic nucleus. A functional biological clock at the systemic and cellular levels is therefore necessary for steroid synthesis and secretion.     

Cellular adaptation contributes to calorie restriction-induced preservation of skeletal muscle in aged rhesus monkeys

We have previously shown that a 30% reduced calorie intake diet delayed the onset of muscle mass loss in adult monkeys between ~16 and ~22 years of age and prevented multiple cellular phenotypes of aging. In the present study we show the impact of long term (~17 years) calorie restriction (CR) on muscle aging in very old monkeys (27-33 yrs) compared to age-matched Control monkeys fed ad libitum, and describe these data in the context of the whole longitudinal study. Muscle mass was preserved in very old calorie restricted (CR) monkeys compared to age-matched Controls. Immunohistochemical analysis revealed an age-associated increase in the proportion of Type I fibers in the VL from Control animals that was prevented with CR. The cross sectional area (CSA) of Type II fibers was reduced in old CR animals compared to earlier time points (16-22 years of age); however, the total loss in CSA was only 15% in CR animals compared to 36% in old Controls at ~27 years of age. Atrophy was not detected in Type I fibers from either group. Notably, Type I fiber CSA was ~1.6 fold greater in VL from CR animals compared to Control animals at ~27 years of age. The frequency of VL muscle fibers with defects in mitochondrial electron transport system enzymes (ETS(ab)), the absence of cytochrome c oxidase and hyper-reactive succinate dehydrogenase, were identical between Control and CR. We describe changes in ETS(ab) fiber CSA and determined that CR fibers respond differently to the challenge of mitochondrial deficiency. Fiber counts of intact rectus femoris muscles revealed that muscle fiber density was preserved in old CR animals. We suggest that muscle fibers from CR animals are better poised to endure and adapt to changes in muscle mass than those of Control animals.     

糖尿病大鼠海马血管紧张素转化酶2表达与认知功能的相关性

目的观察糖尿病大鼠海马血管紧张素转化酶(ACE)2 mRNA和蛋白的表达并探讨其对糖尿病大鼠认知功能的影响。方法 20只雄性SD大鼠随机均分为正常对照组和糖尿病组,建立STZ糖尿病模型,建模成功后11 w用Morris水迷宫测试学习与记忆能力,RT-PCR检测海马ACE2 mRNA的表达,Western印迹检测海马(ACE)2蛋白表达。结果与正常对照组相比,糖尿病组大鼠学习与记忆能力明显减退,其逃避潜伏期时间延长(P<0.05),穿越目标区域次数减少(P<0.05);海马ACE2 mRNA和ACE2蛋白表达明显降低(P<0.05)。结论糖尿病大鼠海马(ACE)2 mRNA和蛋白表达下调与糖尿病大鼠认知功能障碍有关。     

BILN2061、telaprevir和boceprevir治疗慢性丙型肝炎临床疗效比较

HCV感染易导致慢性肝炎、肝硬化及肝癌等相关性疾病,病死率较高.HCV在体内的翻译是经宿主信号肽和非结构蛋白(non-structural protein,NS)3病毒蛋白酶水解成熟.此外,NS3还可直接破坏宿主细胞,抑制其对干扰素的应答,因此研究HCV NS3具有重要的临床意义.本文通过对3种NS3/4A蛋白酶抑制剂(BILN 2061、telaprevir和boceprevir)的药理作用、药动学与代谢、安全性和临床研究进行分析,总结其作用特性和临床疗效.同时,对boceprevir和telaprevir(VX-950)分别联合聚乙二醇干扰素和利巴韦林的疗效进行评价,为临床医生治疗慢性丙型肝炎提供指导.     

Profiling of differentially expressed genes in haemophilia A with inhibitor

Inhibitor development is the most significant complication in the therapy of haemophilia A (HA) patients. In spite of many studies, not much is known regarding the mechanism underlying inhibitor development. To understand the mechanism, we analysed profiles of differentially expressed genes (DEGs) between inhibitor and non-inhibitor HA via a microarray technique. Twenty unrelated Korean HAs were studied: 11 were non-inhibitor and nine were HA with inhibitor (≥5 BU mL(-1)). Microarray analysis was conducted using a Human Ref-8 expression Beadchip system (Illumina) and the data were analysed using Beadstudio software. We identified 545 DEGs in inhibitor HA as compared with the non-inhibitor patients; 384 genes were up-regulated and 161 genes were down-regulated. Among them, 75 genes whose expressions were altered by at least two-fold (>+2 or <-2) were selected and classified via the PANTHER classification method. The expressions of signal transduction and immunity-related genes differed significantly in the two groups. For validation of the DEGs, semi-quantitative RT-PCR (semi-qRT-PCR) was conducted with the six selected DEGs. The results corresponded to the microarray data, with the exception of one gene. We also examined the expression of the genes associated with the antigen presentation process via real-time PCR. The average levels of IL10, CTLA4 and TNFα slightly reduced, whereas that of IFNγ increased in the inhibitor HA group. We are currently unable to explain whether this phenomenon is a function of the inhibitor-inducing factor or is an epiphenomenon of antibody production. Nevertheless, our results provide a possible explanation for inhibitor development.     

Angiotensin-converting enzyme gene insertion/deletion polymorphism and essential hypertension in the Chinese population: a meta-analysis including 21,058 participants

Background: The angiotensin‐converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been suggested to influence susceptibility to essential hypertension (EH), but the results of many individual studies are conflicting. Aim and methods: To explore the relationship between the ACE gene I/D polymorphism and EH in the Chinese population, 67 separated studies were analyzed in a meta‐analysis including 21 058 participants. The electronic databases PubMed, Embase, Web of Science, China Biological Medicine Database and China National Knowledge Infrastructure were searched. The pooled odds ratio (ORs) and its corresponding 95% confidence interval were calculated by the random effects model. Results: In this ACE I/D gene polymorphism meta‐analysis, the distribution of the D allele frequency was 0.45 for the EH group and 0.40 for the control group. The summary OR for the distribution frequency of D allele was 1.27 (5% confidence interval 1.17–1.37). The heterogeneity among the 67 studies was also significant (P < 0.00001, I²= 71.4%). There was a significant association between distribution frequency of the D allele and EH risk in Han, Kazakh, Tibetan, Zhuang and unclassified nationalities (P < 0.05). In contrast, in the national minorities, such as Mongolian, Uigur, Yi, Dongxiang, Yugu, Korean and Gamel, the association between distribution frequency of the D allele and EH risk was not significant (P > 0.05). Conclusions: In the whole Chinese population, the D allele was significantly linked with EH susceptibility. However, the relation between the I/D polymorphism and EH is still inconclusive in some national minorities and must await larger scale studies.     

增龄是雄性大鼠碘对比剂急性肾损伤的促进因素

目的研究年龄对雄性大鼠碘对比剂急性肾损伤（CI．AKI）的影响。方法36只雄性SD大鼠根据月龄分为4月龄组、12月龄组和24月龄组,每组12只,各年龄组大鼠再随机分为正常对照组和对比剂组6个亚组,每组6只。禁水24h后,不同年龄鼠对比剂组大鼠尾静脉注射碘对比剂76％泛影葡胺（10ml／kg）,相应对照组大鼠尾静脉注射等量生理盐水。检测尿肌酐（UCr）、尿N-乙酰-B．D．氨基葡萄糖苷酶（NAG）、血肌酐（SCr）、内生肌酐清除率（Ccr）、肾组织匀浆脂质过氧化物丙二醛（MDA）含量及血管紧张素转换酶（ACE）活性水平。48h后处死动物,观察肾脏的病理改变并检测。肾组织Sp1蛋白表达。结果注射对比剂后48h,24月龄鼠对比剂组SCr水平显著升高（P〈0．01）,且升高幅度超过对照组的25％,Ccr明显下降（P〈0．05）,肾组织匀浆ACE活性和MDA含量和肾小管损伤分数均明显增加（P〈0．01）,肾组织Sp1蛋白的表达明显上调（P〈0．05）;注射对比剂后24h尿NAG酶活性明显较注射前24h增高（P〈0．001）。12月龄鼠注射对比剂组与相应对照组比较,Scr明显上升（P〈0．05）,但升高幅度小于对照组的25％,肾组织匀浆MDA和ACE、肾小管损伤分数以及肾组织Sp1蛋白表达有上升趋势,但均无统计学意义（P〉0．05）。4月龄鼠注射对比剂组与相应对照组相比,上述各项指标比较均无统计学意义（P〉0．05）。结论增龄是雄性大鼠碘CI—AKI的促进因素,氧化性应激、ACE和核转录因子Sp1在老龄雄性大鼠碘CI-AKI发病机制中起一定作用。     

Should we listen to our clock to prevent type 2 diabetes mellitus?

The circadian clock drives a number of metabolic processes including energy intake, storage and utilization coupled with the sleep/wake cycles. Globally, the increasing prevalence of type 2 diabetes (T2DM) has become a significant international public health concern. In view of the heavy societal burden caused by diabetes, and further, to reduce its growing incidence, it is clearly essential to understand the causes of this disease and to devise more effective strategies for its treatment. Although many factors cause T2DM, this article centers on the role of circadian regulation of metabolism. The correlation between the increased occurrence of T2DM and the ubiquity of modern social pressures such as 24/7 lifestyles as well as nocturnal lighting conditions point strongly to the hypothesis that malfunctioning of circadian controls may be involved in the etiology of the illness. Nocturnal light exposure, unusual timing of food, irregular sleep/wake schedules and traveling between different time zones are some of the factors responsible for improper entrainment of the clock. Recent reports have proposed that strengthening of circadian clock functioning and proper timing of food intake could stabilize glucose homeostasis. This strategy thus represents a chronotherapeutic option for non-pharmaceutical intervention in treating T2DM patients.     

CYP2C19基因多态性与介入治疗后氯吡格雷药物疗效的相关性研究

目的探讨PCI术后CYP2C19基因多态性与不同剂量氯吡格雷药物效果的相关性。方法通过基因芯片检测技术,筛选PCI术后CYP2C19基因突变为CYP2C19*2/*2、CYP2C19*2/*3或CYP2C19*3/*3的患者67例,随机分为常规组22例、2倍组22例和3倍组23例。常规组75 mg氯吡格雷、2倍组150 mg氯吡格雷、3倍组225 mg氯吡格雷,1次/d。分别于PCI术后1、3、6个月通过血栓弹力图检测各组氯吡格雷药物抑制率及再发心血管缺血事件发生率。结果 PCI术后6个月内,2倍组和3倍组患者心血管缺血事件发生率较常规组明显降低(81.8%vs 31.8%vs 21.7%,P<0.01),2倍组与3倍组比较差异无统计学意义(P>0.05)。术后1、3、6个月2倍组和3倍组氯吡格雷药物抑制率较常规组显著升高(P<0.01),2倍组与3倍组比较差异无统计学意义(P>0.05)。3组出血风险比较差异无统计学意义(P>0.05)。结论 CYP2C19基因变异患者增加氯吡格雷药物服用剂量,可在一定程度上提高血小板的抑制,降低心血管缺血事件发生率,且不增加出血事件的发生率。