关键词： Clock基因   昼夜节律   光照   视交叉上核   松果体  

摘要： 本研究旨在观察和比较视交叉上核(suprachiasmatic nucleus,SCN)与松果体(pineal gland,PG)中Clock基因内源性昼夜转录变化规律以及光照对其的影响。Sprague-Dawley大鼠在持续黑暗(constant darkness,DD)和12 h光照：12 h黑暗交替(12 hour- light：12 hour-dark cycle,LD)光制下分别被饲养8周(n=36)和4周(n=36)后,在一昼夜内每隔4 h采集一组SCN和PG组织(n=6),提取总RNA,用竞争性定量RT-PCR测定不同昼夜时点(circadian times,CT or zeitgeber times,ZT)各样品中Clock基因的mRNA相对表达量,通过余弦法和Clock Lab软件获取节律参数,并经振幅检验是否存在昼夜节律性转录变化。结果如下：(1)SCN中Clock基因mRNA的转录在DD光制下呈现昼低夜高节律性振荡变化(P＜0．05),PG中Clock基因的转录也显示相似的内源性节律外观,即峰值出现于主观夜晚(SCN为CT15,PG为CT18),谷值位于主观白天(SCN为CT3,PG为CT6)(P＞0．05)。(2) LD光制下SCN中Clock基因的转录也具有昼夜节律性振荡(P＜0．05),但与其DD光制下节律外观相比,呈现反时相符律变化(P＜0．05),且其表达的振幅及峰值的mRNA水平均增加(P＜0．05),而PG中Clock基因在LD光制下转录的相应节律参数变化却恰恰相反(P＜0．05)。(3)在LD光制下,光照使PG中Clock基因转录的节律外观反时相于SCN(P＜0．05),即在SCN和PG的峰值分别出现于光照期ZT10和黑暗期ZT17,谷值分别位于黑暗期ZT22和光照期ZT5。结果表明,Clock基因的昼夜转录在SCN和PG中存在同步的内源性节律本质,而光导引在这两个中枢核团调节Clock基因昼夜节律性转录方面有着不同的作用。

关键词： circadian pacemaker   internal synchronization   RPER2 MESSENGER-RNA   PHASE SYNDROME   SUPRACHIASMATIC NUCLEUS   MELATONIN TREATMENT   BODY-TEMPERATURE   SIGHTED MAN   CORTISOL   LIGHT   ASSOCIATION   PACEMAKER  

摘要： In recent years, circadian rhythm sleep disorders in humans have been increasing. Clinical features characteristic of this disorder are well known, but the specific causes remain unknown. However, various derangements of circadian expression of the clock gene are a probable cause of this disease. We have attempted to elucidate the relationship between the expression of the clock genes in whole blood cells and the clinical features characteristic of this disorder. In this study, we indicate the daily expression of clock genes period (Per) 1, 2, 3, Bmal1, and Clock in whole blood cells in 12 healthy male subjects. The peak phase of Per1, Per2, and Per3 appeared in the early morning, whereas that of Bmal1 and Clock appeared in the midnight hours. Furthermore, in one patient case with circadian rhythm sleep disorder, we observed variations of the peak phase in clock genes by treatments such as light therapy, exercise therapy, and medicinal therapy. This study suggested that the monitoring of human clock genes in whole blood cells, which may be functionally important for the molecular control of the circadian pacemaker as well as in suprachiasmatic nucleus, might be useful to evaluate internal synchronization.

关键词： 帕金森氏病   昼夜节律   视交叉上核   时钟基因   多巴胺能神经元   神经元损伤  

摘要： 目的:研究MPTP制备的PD小鼠组织中昼夜节律相关基因—时钟基因的表达变化及其发生机制,并探讨多巴胺能神经元损伤对机体节律相关基因及昼夜节律的影响.结论:MPTP作用使未定带-下丘脑多巴胺系统-A13多巴胺能神经元受损,多巴胺释放减少,可能通过多巴胺受体影响到SCN及下丘脑的功能,导致中枢和周围组织细胞内节律振荡器改变,时钟基因表达时相发生改变,使脑组织mPer1表达增加,心脏mPer1以及肝脏mPer1、mPer2表达时相提前,但表达幅度未变.提示多巴胺与昼夜节律密切相关,可能是导致PD非运动症状的原因.

关键词： 高血压   昼夜节律   颈动脉硬化  

摘要： 目的探讨老年高血压患者血压昼夜节律与颈动脉粥样硬化的相关性。方法2003￣2004年来我院老年高血压患者共72例(男68例女4例),根据动态血压监测(ABPM)结果分为正常昼夜节律组,即杓型组(n=37,男35例女2例)和异常昼夜节律组,即非杓型组(n=35,男33例女2例)。对所有患者均行颈动脉超声检查,测定右侧颈总动脉(RCCA)、颈内动脉(RICA)内膜中层厚度(IMT)、管腔内径(D),并计算各自的IMT/D值,测定右侧颈动脉分叉处(RBIF)的IMT,观察并记录双侧颈动脉系统斑块的大小、数量。结果(1)两组年龄(Age)、体重指数(BMI)、总胆固醇(TC)、甘油三酯(TG)、全天平均收缩压(24hMSP)、全天平均舒张压(24hMDP)比较均无显著性差异(P>0.05)。(2)两组的RCCA及RICA的IMT、D、IMT/D比较均无显著性差异(P>0.05)。而右颈动脉分叉处IMT,非杓型组明显高于杓型组(P<0.001)。(3)两组总斑块检出率无显著差异,但多发性斑块检出率非杓型组显著高于杓型组(P<0.05)。结论老年高血压患者血压昼夜节律与颈动脉粥样硬化明显相关,异常的血压昼夜节律提示可能存在更严重的靶器官损害。

关键词： Clock基因   NAT基因   昼夜节律   光照   松果体  

摘要： 探讨12h光照、12h黑暗交替(12h-light:12h-darkcycle,LD)及持续黑暗(constantdarkness,DD)光制下松果体Clock基因和芳烷脘N-乙酰基转移酶基因(arylalkylamineN-acetyltransferasegene,NAT)是否存在昼夜节律性表达及其光反应变化。Sprague-Dawley大鼠在LD和DD光制下分别被饲养4周(n=36)和8周(n=36)后,在一昼夜内每隔4h采集一组松果体组织(n=6),提取总RNA,用竞争性定量RT-PCR测定不同昼夜时点样品中Clock及NAT基因的mRNA相对表达量,通过余弦法和ClockLab软件获取节律参数,并经振幅检验是否存在昼夜节律。结果如下:(1)在DD或LD光制下,松果体Clock和NAT基因mRNA的表达均呈现夜高昼低的节律性振荡(P<0.05)。(2)与DD光制下比较,LD光制下松果体Clock和NAT基因的表达振幅及峰值相的mRNA水平均降低(P<0.05)。(3)在DD或LD光制下,Clock和NAT基因之间显示相似的节律性表达(P>0.05)。结果表明,Clock和NAT基因在松果体中存在同步的内源性昼夜节律表达,光照作用可使其表达下调。

关键词： Arabidopsis thaliana   circadian rhythm   cultured cells   light response   regulatory cis-elements   PSEUDO-RESPONSE REGULATORS   APRR1/TOC1 QUINTET   EARLY PHOTOMORPHOGENESIS   TRANSCRIPTION-FACTOR   SIGNAL-TRANSDUCTION   ABERRANT EXPRESSION   RHYTHMS   PLANTS   WAVES   TOC1  

摘要： In the model higher plant Arabidopsis thaliana, a number of circadian clock-associated protein components have recently been identified. Among them, a small family of ARABIDOPSIS PSEUDO-RESPONSE REGULATORS (APRR1/TOC1, APRR3, APRR5, APRR7, and APRR9) is interesting because the most probable clock component TIMING OF CAB EXPRESSION I (TOC1) belongs to this family. Several lines of evidence have already been accumulated to support the view that not only APRR1/TOC1 but also other APRR family members are crucial for a better understanding of the molecular link between circadian rhythm and light-signal transduction. Among the APRR1/TOC1 family members, the circadian-controlled APRR9 gene is unique in that its expression is rapidly induced by light at the level of transcription. In this study we dissected the regulatory cis-elements of the light-induced and/or circadian-controlled APRR9 promoter by employing not only a mutant plant carrying a T-DNA insertion in the APRR9 promoter, but also a series of APRR9-promoter::LUC (luciferase) reporters that were introduced into an Arabidopsis cultured cell line (T87 cells). Taking the results of these approaches together, we provide several lines of evidence that the APRR9 promoter contains at least two distinctive and separable regulatory cis-elements: an "L element" responsible for the light-induced expression, followed by an "R element" necessary for the fundamental rhythmic expression of APRR9. Furthermore, APRR1/ TOC1 was implicated in the L-element-mediated light response of APRR9, directly or indirectly.

关键词： N-乙酰转移酶基因   昼夜节律   松果体  

摘要： 探讨12 h光照、12 h黑暗交替(LD)光制下松果体N-乙酰转移酶(NAT)基因的昼夜节律性表达。SD大鼠在LD光制下饲养4周后,在一昼夜内每隔4h采集一组松果体组织,提取总RNA,进行竞争性定量RT-PCR,测定不同昼夜时点(ZT)样品中NAT基因mRNA的相对表达量。用余弦函数获取节律参数,并经振幅检验分析是否存在昼夜节律。结果表明松果体NAT基因mRNA表达呈现昼夜节律性振荡(P<0.05),峰值(mRNA水平为1.07±0.23)和谷值(mRNA水平为0.61±0.15)分别位于ZT16和ZT4,峰值相位-241.80±14.94,振幅0.23±0.13,中值0.84±0.11。证实LD光制下松果体NAT基因存在明显的昼低夜高节律性表达。

关键词： sleep deprivation   beta amyloid immunization   Tg2576   electroencephalogram   donepezil   amyloid precursor protein   AMYLOID PRECURSOR PROTEIN   GENE-TARGETED MICE   A-BETA   BASAL FOREBRAIN   SUPRACHIASMATIC NUCLEUS   MEMORY DEFICITS   SENILE-DEMENTIA   CHOLINESTERASE-INHIBITORS   PLAQUE PATHOLOGY   APOLIPOPROTEIN-E  

摘要： The Tg2576 mouse model of Alzheimer's disease (AD) exhibits age-dependent amyloid P (AP) deposition in the brain. We studied electroencephalographically defined sleep and the circadian regulation of waking activities in Tg2576 mice to determine whether these animals exhibit sleep abnormalities akin to those in AD. In Tg2576 mice at all ages studied, the circadian period of wheel running rhythms in constant darkness was significantly longer than that of wild type mice. In addition, the increase in electroencephalographic delta (1-4 Hz) power that occurs during non-rapid eye movement sleep after sleep deprivation was blunted in Tg2576 mice relative to controls at all ages studied. Electroencephalographic power during non-rapid eye movement sleep was shifted to higher frequencies in plaque-bearing mice relative to controls. The wake-promoting efficacy of the acetylcholinesterase inhibitor donepezil was lower in plaquebearing Tg2576 mice than in controls. Sleep abnormalities in Tg2576 mice may be due in part to a cholinergic deficit in these mice. At 22 months of age, two additional deficits emerged in female Tg2576 mice: time of day-dependent modulation of sleep was blunted relative to controls and rapid eye movement sleep as a percentage of time was lower in Tg2576 than in wild type controls. The rapid eye movement sleep deficit in 22 month-old female Tg2576 mice was abolished by brief passive immunization with an N-terminal antibody to Abeta. The Tg2576 model provides a uniquely powerful tool for studies on the pathophysiology of and treatments for sleep deficits and associated cholinergic abnormalities in AD. (C) 2005 Published by Elsevier Ltd on behalf of IBRO.

关键词： circadian rhythm   clock-mutant mouse   restricted feeding   food-anticipatory activity   liver   SUPRACHIASMATIC NUCLEUS   MESSENGER-RNA   ANTICIPATORY ACTIVITY   FEEDING SCHEDULES   RATS   LESIONS   MODELS   OUTPUT   SLEEP   LIVER  

摘要： Restricted feeding-induced free-running oscillation of clock genes in the liver was studied in homozygous Clock-mutant (Clock/Clock) mice. Similar to wild-type mice, Clock/Clock mice showed robust food-anticipatory behavioral activity in accordance with a restricted feeding schedule. Also, the peak of all clock gene mRNAs tested was phase-advanced in the liver of Clock/Clock mice as well as wild-type mice, although the amplitude of clock gene expression was low in Clock/Clock mice. The food-anticipatory behavioral rhythm in Clock/Clock mice maintained a period similar to wild-type mice during 2-day fasting after the cessation of restricted feeding. However, during the fasting days after temporal feeding cues were removed, the oscillation of clock genes in the liver and heart, excluding the suprachiasmatic nuclei, appeared to result in arrhythmicity in Clock/Clock mice. Thus, although the CLOCK-based molecular mechanism is not required for the expression of food-anticipatory activity, intact CLOCK protein might be involved in sustaining several cycles of peripheral circadian oscillations after restricted feeding-induced resetting. (c) 2005 Published by Elsevier Ltd on behalf of IBRO.

关键词： casein kinase   polymorphism   single nucleotide   phosphorylation   biological clocks   case-control studies   risk factors   PHASE SYNDROME   WAKE SYNDROME   MELATONIN RHYTHMS   CKI-EPSILON   DOUBLE-TIME   CLOCK GENE   PERIOD   PHOSPHORYLATION   MUTATION   DELTA  

摘要： Recent studies have shown that functional variations in clock genes, which generate circadian rhythms through interactive positive/ negative feedback loops, contribute to the development of circadian rhythm sleep disorders in humans. Another potential candidate for rhythm disorder susceptibility is casein kinase I epsilon (CKIepsilon), which phosphorylates clock proteins and plays a pivotal role in the circadian clock. To determine whether variations in CKIe induce vulnerability to human circadian rhythm sleep disorders, such as delayed sleep phase syndrome (DSPS) and non-24-hsleep-wake syndrome (N-24), we analyzed all of the coding exons of the human CKIe gene. One of the variants identified encoded an amino-acid substitution S408N, eliminating one of the putative autophosphorylation sites in the carboxyl-terminal extension of CKIepsilon. The N408 allele was less common in both DSPS ( p = 0.028) and N-24 patients ( p = 0.035) compared to controls. When DSPS and N-24 subjects were combined, based on an a priori prediction of a common mechanism underlying both DSPS and N-24, the inverse association between the N408 allele and rhythm disorders was highly significant ( p = 0.0067, odds ratio = 0.42, 95% confidence interval: 0.22 - 0.79). In vitro kinase assay revealed that CKIe with the S408N variation was similar to1.8-fold more active than wild-type CKIepsilon. These results indicate that the N408 allele in CKIe plays a protective role in the development of DSPS and N-24 through alteration of the enzyme activity.