Improving circadian rhythm disturbance reduces myocardial ischemia-reperfusion injury in diabetic rats / 基础医学与临床

Objective To investigate whether discontinuous sleep supplementation can reduce myocardial ischemia-reperfusion injury in diabetic rats aggravated by circadian rhythm disorder.Methods The rats were injected intra-peritoneal with 1％streptozotocin(STZ)30 mg/kg combined with high-fat and high-glucose diet to replicate diabetic model.Forty diabetic rats were randomly divided into four groups with 10 in each:sham surgery group(Sham group),ischemia-reperfusion group(I/R group),in which the left anterior descending coronary artery(LDA)was ligated for thirty minutes and reperfusion for 2 h,circadian rhythm disorder group(Crd group,24 h daily light and food),discontinuous sleep supplementation group(Dss group,every 3 hours of illumination and 1.5 hours break at night).We analyzed the myocardial infarct size(by 2,3,5-triphenyltetrazolium chloride stai-ning),determined serum creatine kinase-myoglobin(CK-MB)activity and cardiac troponinⅠ(cTnⅠ)concentrations;the expression level of BMAL1 and REV-ERBα was determined by Western blot.Results Compared to the sham group,the I/R group showed a significantly increased in myocardial infarct size,serum CK-MB activity and cTnⅠ concentration.The expression of the myocardial biological clock gene BMAL1 was down-regulated,while the ex-pression of REV-ERBα was up-regulated(P<0.05).Compared to the I/R group,the Crd group showed a signifi-cantly increase in myocardial infarct size,serum CK-MB activity and cTnⅠ concentration.The expression of the myocardial biological clock gene BMAL1 was down-regulated,while the expression of REV-ERBα was up-regulated(P<0.05).Compared to the Crd group,Dss group showed a significantly decrease in the myocardial infarct size,serum cTn concentration and CK-MB activity.Furthermore,there was an increased protein expression of BMAL1 and a decrease of REV-ERBα(P<0.05).Conclusions Discontinuous sleep supplementation can reduce myocardial is-chemia-reperfusion injury in diabetic rats aggravated by circadian rhythm disorder.

Effects of biological clock gene Bmal1 on the expression of cell cycle-associated genes in chondrocytes / 基础医学与临床

Objective To explore the intrinsic relationship between circadian clock and cell cycle in osteoarthritis(OA)chondrocytes,especially the regulation of cell cycle-related genes by the clock gene Bmal1.Methods The chondroid ATDC5 cells induced by insulin-transfering-selenium(ITS)were divided into control group,OA group and LV-Bmal1 group.The cell viability of each group was detected by CCK8 method.The expression of Bmal1,Per1,Wee1,Cdk1,Ccnb1 and Mmp13 mRNA in each group was detected by RT-qPCR.The expression of BMAL1,PER1,WEE1,CDK1,CCNB1 and MMP13 protein in each group was detected by Western blot.The effects of Bmal1 on different stages of cell cycle and apoptosis was analyzed by flow cytometry.The regulation of Bmal1 on Per1,Wee1,Cdk1,Ccnb1 and Mmp13 and their roles in OA were analyzed.Results Compared with the normal group,the cell viability of the OA group was increased,the relative mRNA expression of Bmal1 and Wee1 in the OA group decreased,and the relative mRNA expression of Per1,Cdk1,Ccnb1 and Mmp13 increased signif-icantly.The cell viability of LV-Bmal1 group decreased,the relative expression of Bmal1 and Wee1 mRNA in-creased,and the relative expression of Per1,Cdk1,Ccnb1 and Mmp13 mRNA decreased(P＜0.05).Correlation analysis showed that Bmal1 was positively correlated with Wee1 and they were negatively correlated with Per1,Cdk1,Ccnb1 or Mmp13.The results of Western blot showed that protein expression in different groups were con-sistent with the trend of PCR.The results of cell cycle and apoptosis showed that compared with the normal group,the S phase and G2/M phase of the OA group were shortened,the proportion of cells decreased significantly,and the proportion of early and late apoptosis increased.The S phase and G2/M phase of the LV-Bmal1 group were prolonged,the proportion of cells was increased,and the proportion of early and late apoptosis was decreased.Conclusions Circadian clock gene Bmal1 in inflammatory chondrocytes might regulate the expression of cell cycle-related genes.

Exploration and Practice of Curriculum Construction of Biological Clock and Health / 生物化学与生物物理进展

General education in natural sciences is a critical component in higher education. In this article, I introduced the exploration and practice of curriculum construction of “Biological Clock and Health” at Tsinghua University. The course has been open to students for 3 semesters so far. Students who selected the course come from 27 departments of the university. The students provided positive feedbacks after taking this class, including self-report of improved sleep quality and better understanding of the research logic and methods in life sciences. The logic and methods of the construction of “Biological Clock and Health” described in this article provide insights to the construction of other courses in natural sciences of general education.

Effects of long-term noise exposure during sleep on cognitive function and biological clock-related mechanisms in mice / 环境与职业医学

Background Environmental noise pollution is serious, and there are few studies on the effects of long-term noise exposure during sleep on cognitive function and possible biological clock mechanism. Objective To explore the cognitive impairment induced by noise exposure during sleep in mice and possible biological clock mechanism, and to provide a theoretical basis for the protection against noise exposure. Methods Twenty male C57BL/6J mice were randomly divided into a control group and a noise-exposed group, 10 mice in each group. The noise-exposed group was exposed to sleep-period noise using a noise generator for 12 h (08:00–20:00) per day for a total of 30 d. The calibrated noise intensity was set at 90 dB. No intervention was imposed on the control group. At the end of the noise exposure, cognitive function of mice was examined using the new object recognition experiment and the open field test, and the hippocampal tissue damage of mice were evaluated by Nissl staining, ionized calcium binding adaptor molecule 1 (Iba1) immunofluorescence staining, and real-time fluorescence quantitative PCR for inflammatory factors and biological clock genes. Oxidative stress indicators in the hippocampus of mice were also detected by assay kit. Results After noise exposure during sleep period, the results of new object recognition experiment showed that the discrimination index of mice in the noise-exposed group was 0.06±0.04, which was significantly lower than that of the control group (0.65±0.13) (P<0.05). The results of open field test showed that the central activity distance of the noise-exposed group was (242.20±176.10) mm, which was significantly lower than that of the control group, (1548.00±790.30) mm (P < 0.05), and the central activity time of the noise-exposed group was (0.87±0.64) s, which was significantly lower than that of the control group, (6.00±2.86) s (P < 0.05). The Nissl staining results showed that compared with the control group, neurons in the hippocampus of the noise-exposed mice were shrunken, deeply stained, disorganized, and loosely connected. The immunofluorescence results showed that microglia in the hippocampus of the noise-exposed mice were activated and the expression of Iba1 was significantly increased compared with those of the control group (P<0.05). The real-time PCR results of showed that the mRNA levels of the biological clock genes Clock, Per2, and Rev-erbα were significantly increased compared with those of the control group (P<0.05), and the mRNA level of Per1 was significantly decreased compared with that of the control group (P<0.05); and the mRNA levels of IL-18, IL-6, iNOS, and NLRP3 in the hippocampal tissues of mice were significantly increased compared with those of the control group (P<0.05). The results of oxidative stress evaluation showed that compared with the control group, reduced glutathione content was significantly reduced in the noise-exposed group (P<0.001). Conclusion Noise exposure during sleep period can lead to the destabilization of biological clock genes in hippocampal tissues and trigger hippocampal neuroinflammation, which can lead to the activation of microglia and cause cognitive impairment in mice.

The Influence of Biological Clock System on the Circadian Rhythm of Sleep Based on Essence-Qi-Spirit Theory / 中医杂志

The essence-qi-spirit theory is an important part of traditional Chinese medicine， whose steady state is the material and functional basis for the balance of yin and yang in the body， making the essence， qi and spirit integrated， and body and spirit harmonized. Based on this theory， it is proposed that essence and qi depletion， spirit dissipation and qi dispersion， disharmony between yin and yang is the main pathogenesis of sleep disorders. Therefore， the method of regulating and harmonzing yin and yang by essence gathering， qi nourishing and spirit storing can be used to treat sleep disorder. The biological clock system of the circadian rhythm of sleep is regulated by the molecular oscillation that is generated by the transcription of the biological clock gene， and is a clock gradually formed by orga-nisms constantly adapting to the laws of nature. As the material basis， power， and embodiment of sound and peaceful sleep， essence， qi and spirit can perceive and transmit natural signals， whose functions are similar to what is recognized by modern science that oscillation amplifies the rhythm signal， and synchronously regulates the expression signal of the biological clock gene， thereby forming a biological clock system with “input-oscillation-output” as the feedback cycle. It is believed that the regulation method of yin and yang by essence gathering， qi nourishing and spirit storing may comprehensively regulate the physiological activities through brain/ muscle aryl hydrocarbon receptor nuclear translocator-like protein 1 （BMAL1）/circadian locomotor output cycles kaput （CLOCK）-period protein （PER）/ cryptochrome （CRY） transcriptional feedback loop， thereby adapting to the natural environment changes， playing an active role in the treatment of sleep disorders， and provideing a new idea for traditional Chinese medicine to reshape the molecular regulation system of the endogenous biological clock to prevent and treat sleep disorders.

Research progress of circadian rhythm and circadian clock gene regulation in the development of myopia / 国际眼科杂志(Guoji Yanke Zazhi)

With the development of society, the incidence of myopia and the population of myopia has increased year by year, which has become a major public health problem. Therefore, the research on the pathogenesis and prevention and control measures of myopia is imminent. In recent years, the role of the biological clock in the development of myopia has gradually attracted scholars interest. Now the author starts from the impact of the biological clock on the axial length, retina and choroid in the development of myopia. In order to provide new ideas for the study of prevention and control measures and the pathogenesis of myopia, a brief review is made from the perspective of contemporary society and disrupted body clock.

Research progress on the biological clock genes and diabetic retinopathy / 中华眼底病杂志

Diabetic retinopathy (DR) is one of the most common and serious complication of diabetes mellitus, which is the main cause of vision loss in adults. Biological clock genes produce circadian rhythms and control its operation, while the disorder of the expression causes the occurrence and development of a series of diseases. It has been demonstrated that biological clock genes might take effects in the development and progression of DR. On the one hand, circadian rhythm disorder-related behavior disrupts the circadian oscillation of clock genes, and the change in its expression level is prone to unbalanced regulation of glucose metabolism, ultimately increasing the risk of type 2 diabetes mellitus and DR pathogenesis. On the other hand, DR patients exhibit symptoms of circadian rhythm disorders, and it has been suggested that the clock genes may control the development and progression of DR by affecting a variety of retinal pathophysiological processes. Therefore, maintaining normal circadian rhythm can be used as a disease prevention strategy, and studying the molecular mechanism of clock genes in DR can provide new ideas for more comprehensive elaboration of the pathogenesis of DR and search for new therapeutic targets.

Research progress on the regulation mechanism of the eye's biological clock / 国际眼科杂志(Guoji Yanke Zazhi)

@#The circadian rhythm is a set of autonomous endogenous oscillators resulting nearly 24h cycles. The biological clock, including central and peripheral biological clock, is a clock system that regulates the circadian rhythm of the body. The biological clock gene and its encoded protein constituent the transcription-translation oscillation loop, which could regulate the circadian rhythm of biochemical, physiological, and behavioral processes through neural and humoral pathways. The mammalian eyeball contains a complete biological clock system, thus controlling the circadian rhythm of important physiological functions and various parameters of the eyeball. Abnormal circadian clock genes caused by various reasons will affect the circadian rhythm and may lead to the occurrence and development of the ocular diseases. Therefore, the pathogenesis and clinical manifestations of ocular diseases are characterized by diurnal variation. The change of circadian clock gene expression is not only involved in the pathophysiological process of ocular diseases, but also may be an important target for the prevention and treatment of diseases. This article introduces the circadian rhythm characteristics of corneal disease, glaucoma and myopia and the related biological clock regulation mechanism. Further research on the circadian clock provides a new strategy for the prevention and treatment of ocular diseases.

The biological clock gene BMAL1 inhibits the proliferation, migration and invasion of radiation-resistant nasopharyngeal carcinoma cell line 5-8FR by regulating PI3K/Akt/MMP-2/9 signaling pathway / 中华放射肿瘤学杂志

Objective:To investigate the effect of BMAL1 gene on the proliferation, migration and invasion ability of radiation-resistant nasopharyngeal carcinoma cell line (5-8FR) and the molecular mechanism. Methods:A multi-target click model was constructed for radiation-resistant nasopharyngeal carcinoma cell line 5-8FR by low-dose fractionated irradiation, and the results of clone formation assay were used to fit the multi-target click model and calculate the sensitization ratio of radiotherapy. The expression levels of PI3K/Akt/MMP-2/9 signaling pathway-related proteins in 5-8FR and control 5-8F cell lines were detected by Western blot. The overexpression and knockdown vectors of BMAL1 gene were constructed and transfected with 5-8F and 5-8F cell lines, respectively. The BMAL1 gene overexpression (pcDNA-BMAL1) and its control (pcDNA) and interference (BMAL1-shRNA) and control (con-shRNA) cell lines were stably transfected with nasopharyngeal carcinoma cell line 5-8F and radiation-resistant cell line 5-8FR, respectively. Western blot was performed to verify the infection efficiency and detect the changes of PI3K/Akt/MMP-2/9 signaling pathway-related proteins after overexpression or interference of BMAL1 gene in both groups of cells. CCK-8 assay, cell scratch test and Transwell chamber test were conducted to investigate the proliferation, migration and invasion capabilities of 5-8FR cell line after overexpression or interference of BMAL1 gene. Results:BMAL1 gene expression was down-regulated, and those of PI3K/Akt pathway proteins and downstream related molecules of MMP-2 and MMP-9 were up-regulated, and TIMP-2 and TIMP-1 expression was down-regulated in nasopharyngeal carcinoma radiation-resistant cell lines. Overexpression of BMAL1 gene inhibited the expression of PI3K/Akt pathway proteins and downstream related molecules of MMP-2 and MMP-9, promoted the expression of TIMP-2 and TIMP-1, and inhibited the proliferation, migration and invasion capabilities of radiation-resistant nasopharyngeal carcinoma cells, while interference with BMAL1 gene yielded the opposite results. Conclusions:BMAL1 gene can reverse the expression of PI3K/Akt/MMP-2/9 signaling pathway-related proteins in radiation-resistant nasopharyngeal carcinoma cell lines and inhibit the proliferation, migration and invasion capabilities of radiation-resistant nasopharyngeal carcinoma cell lines.

Research progress on relationships of circadian rhythm with thyroid function and diseases / 环境与职业医学

Circadian rhythm is a phenomenon of diurnal changes in life activities formed by a transcription-translation feedback loop of biological clock genes affected by external environmental conditions. The circadian rhythm system controls almost all physiological processes in the organism, and these processes will change as the external environment changes. Previous studies have shown that the hypothalamic-pituitary-thyroid axis in mammals is regulated by the central diurnal pacemaker of the suprachiasmatic nucleus of the hypothalamus, so part of the thyroid function is controlled by the biological clock, and the secretion of thyroid hormones in blood can present a circadian rhythm. However, the molecular mechanism of the biological clock's regulatory effect on thyroid is still unclear. Whether circadian rhythm interference is related to the disorder of thyroid function or the occurrence of thyroid diseases is worthy of attention. This paper focused on the research progress of biological clock, circadian rhythm, and thyroid function, specifically the characteristics of circadian rhythm of thyroid physiological function and the effects of sleep deprivation, light at night, and night shift work on thyroid function, elaborated the relationships of circadian rhythm disorder with thyroid function and thyroid diseases represented by thyroid malignant tumors. The review summarized that circadian rhythm disorder may disrupt the rhythmic secretion of thyroid hormones, but no clear conclusion is reached yet on any effect on thyroid diseases, especially thyroid malignant tumors, so it is necessary to further strengthen the relevant epidemiological and molecular mechanism research.

Interações entre o relógio biológico e a sinalização do estado energético em plantas do complexo Saccharum / Biological clock and energy sensors in plants from Saccharum complex

A cana-de-açúcar e a cana energia são plantas intercruzáveis que compõe o complexo Saccharum. Estas plantas são fonte de biomassa para produção de açúcar, biocombustíveis, eletricidade, entre outros, e utilizam a energia assimilada pela fotossíntese de forma contrastante, ainda que ambas resultem em alta produtividade. O relógio biológico é um mecanismo molecular que gera informações sobre a hora do dia em conjunto com estímulos ambientais, adaptando respostas fisiológicas em prol de otimizar o desenvolvimento dos organismos em um ambiente cíclico, processo que regula cerca de 64% dos genes de cana-deaçúcar no campo. Em organismos sésseis como as plantas, o recorrente processo de produção de energia apenas durante o período luminoso, gera ritmos de metabólitos que influenciam na atividade de enzimas quinases que assim funcionam como sensores do estado energético, em vias conservadas nos eucariotos. Porém, pouco se sabe a respeito de como estes sinais são percebidos a nível transcricional, principalmente em plantas cultiváveis. Para elucidar como estas vias atuam em conjunto em plantas do complexo Saccharum, medimos o nível de transcrição de componentes do relógio biológico, de subunidades que compõe o complexo TOR, e da subunidade catalítica de SnRK1, KIN10. Medimos o desempenho do relógio biológico das variedades através da quantificação de amido em quatro pontos temporais, para obter uma dinâmica de produção e consumo, processo que é regulado pelo relógio biológico e tem genes com perfil de expressão rítmicos em cana de-açúcar. Curiosamente, uma das quatro variedades onde identificamos provável perfil rítmico de consumo de amido é a S.officinarum SP80-3280, cana-de-açúcar utilizada anteriormente para estudos de relógio biológico. Os nove acessos foram divididos em dois grupos com base em sua partição de carbono contrastante. HF (high fiber) com mais fibras e perfilho e grupo HS (high sucrose), com maior armazenamento de açúcares e amido que HF, em todos os horários de coleta, e com baixa produção de fibras. Estes grupos não diferem em expressão dos componentes de relógio biológico, no entanto, HS tem maior transcrição de uma subunidade do complexo TOR, em apenas um dos horários analisados (ZT12). Em conjunto, a expressão dos componentes do relógio biológico divide os acessos entre os que possuem altos níveis de transcrição de ScLHY, no ZT03, e os que possuem maior transcrição dos genes PRR59, 73 e 95, no ZT12, grupos com contrastante partição de carbono. A transcrição dos sensores energéticos se correlaciona no começo da noite em acessos de HS e Krakatau e, no começo da manhã, em acessos de HF e IN84-105, sem agrupar as variedades por espécie ou destino de carbono. Este trabalho sugere que há diferentes níveis de correlação entre a transcrição dos genes mensurados e as contrastantes partições de carbono das plantas do complexo Saccharu

Sugarcane and Energycane are intercrossable plants that make up the Saccharum complex. These plants are a source of biomass, sugar, biofuels, electricity among others, and even though they use the energy assimilated by photosynthesis in a contrasting way, both results in high productivity. The biological clock is a molecular mechanism that generates information about the time of day in conjunction with environmental stimuli, adapting physiological responses to optimize the development of organisms in a cyclic environment, a process that regulates about 64% of sugarcane genes in field-grown plants. In organisms such as plants, the recurrent process of energy production that happens only during the luminous period generates rhythmicity that may influence the activity of kinase enzymes, thus giving an energy sensor property for then. However, little is known about how these signs are perceived at the transcriptional level, especially in crops and monocots. To elucidate how these pathways act together in plants of the Saccharum complex, we measured the transcription level of the daytime loop of the biological clock, subunits that make up the TOR complex, and the catalytic subunit of SnRK1, KIN10. We measured starch content in four time points, to obtain a dynamic of production and consumption, a process that is regulated by the biological clock and has genes with a rhythmic expression profile in sugarcane. Interestingly, one of the four varieties where we could identify a probable rhythmic profile of starch consumption is a sugarcane SP80-3280 (S. officinarum), that have been used for biological clock studies. The nine genotypes were divided into two groups based on their contrasting carbon partition. HF (high fiber) with more fiber and tiller and group HS (high sucrose), with higher sugar and starch storage than HF, but with lower fiber production. These groups do not differ in expression of biological clock components; however, HS has a higher transcription of a subunit of the TOR complex, in only one of the analyzed times (ZT12). Together, the expression of components of the biological clock divides the genotypes between those with higher levels of ScLHY in ZT03 and those with more transcripts of PRR59, 73 and 95 genes in ZT12, groups that also have contrasting carbon partition. The transcription of TOR complex correlates in the early evening in HS and KRAKATAU, but in the morning, in HF and IN84-105, with no clear correlation with the C destination preferences. This work suggests that there are different levels of correlation between the transcription of biological clock and energy sensors component genes and the contrasting carbon partitions of plants from the Saccharum complex

The molecular mechanism by which the circadian rhythm regulates body metabolism and research progress on intervention in the circadian rhythm by traditional Chinese medicine / 药学学报

Circadian rhythm is an internal regulatory mechanism that allows organisms to adapt to circadian changes in the external environment, and can regulate the body's steady state by affecting the metabolic pathways of multiple organs. When exogenous factors such as eating time, worktime changes, and sleep disturbances cause the body's circadian rhythm to be disrupted, the risk of developing metabolic syndrome is significantly increased. This article explores the relationship between circadian rhythm and body metabolism and summarizes the molecular mechanisms by which circadian rhythm regulates the digestive system, liver and bile acid production, and kidney function. We review research progress on intervention in the circadian rhythm by traditional Chinese medicine and provide a reasonable and valuable basis for follow-up studies on the role of traditional Chinese medicine in research on the molecular mechanisms of regulation of circadian rhythm.

Improvement Effects of Isopimpinelline on PCPA-induced Pineal Gland Injury Model Rats and Its Effects on Expression of Biological Clock Gene / 中国药房

OBJECTIVE：To study the improvement effects of isopimpinelline on p-chlorophenylalanine（PCPA）-induced pineal injury model rats and its effect on expression of biological clock gene. METHODS ：Totally 60 rats were divided into blank control group（2％ polysorbate solution），model control group （2％ polysorbate solution），positive control group （melatonin，10 mg/kg） and isopimpinelline high-dose ，medium-dose and low-dose groups （3，1.5，0.75 mg/kg）. Except for blank control group ，rats in other groups were given PCPA intraperitoneally （450 mg/kg）to establish pineal injury model. After modeling finished ，they were given relevant medicine intragastrically ，once a day ，for consecutive 7 d. On the 6th day of administration ，the sleep latency and sleep duration of rats in each group were investigated by pentobarbital sodium coordination sleep test ；after last administration ， ELISA assay was used to determine the serum level of melatonin in rats. Fluorescence microscope and electron microscope were used to observe the pathological tissue and cell ultrastructure changes of the pineal gland. RT-qPCR was used to detect the mRNA expressions of biological clock gene Clock，Bmal1，Per1，Per2，Per3，Cry1，Cry2 in pineal gland of rats. RESULTS ：Compared with blank control group ，model control group had significantly longer sleep latency （P＜0.05）；serum melatonin ，mRNA expressions of Bmal1 and Per1 in pineal gland were significantly decreased （P＜0.05 or P＜0.01）while mRNA expression of Per3 was increased significantly （P＜0.05）. The pineal gland cell arrangement disorder ，nuclear pyknosis ，vacuolar degeneration increased and cell number decreased significantly ；mitochondria swollen ，cristae broken and pyknosis were observed. Compared with model control group ，the sleep latency of isopimpinelline high-dose group was shortened significantly （P＜0.05），sleep duration time was prolonged significantly （P＜0.05）；the levels of melatonin in serum ，mRNA expressions of Clock，Bmal1， Per1，Cry1 and Cry2 in pineal gland of rats were increased significantly （P＜0.05 or P＜0.01）. In isopimpinelline medium-dose group，the sleep latency was shortened significantly （P＜0.05）；the levels of melatonin in serum and mRNA expressions of Clock， Bmal1，Per1，Cry1，Cry2 in pineal gland were increased significantly （P＜0.05 or P＜0.01），while mRNA expression of Per3 was decreased significantly （P＜0.05）. In isopimpinelline low-dose group ，the levels of mRNA expressions of Clock，Bmal1，Per2 and Cry2 were increased significantly （P＜0.05），while mRNA expression of Per3 was decreased significantly （P＜0.05）. Cell arrangement disorder was improved and nuclear pyknosis vacuole degeneration was decreased to some extent in isopimpinelline groups；mitochondria swelled ，cristae fractured ，and pyknosis decreased to some extent. CONCLUSIONS ：Isopimpinelline can improve PCPA-induced pineal gland injury in rats ；it can up-regulate the expressions of positive regulators Clock，Bmal1 and negative regulators Per1，Per2，Cry1，Cry2，while down-regulate the expression of negative regulator Per3.

Effect of maternal vitamin A deficiency during pregnancy on neurodevelopment of offspring / 上海交通大学学报（医学版）

Vitamin A (VA) is a fat-soluble vitamin with all-trans-retinoic biological activities. In addition to maintaining the normal functions of the eye, skin, immune, and reproductive systems, VA is also widely distributed in brain tissues, and important to the generation and differentiation of neural progenitor cells in the developing nervous system. Pregnant women are susceptible to vitamin A deficiency (VAD). Retinoic acid, the active form of VA, is very important to the brain development of offspring. This article reviews the literatures of maternal VAD during pregnancy, summarizing the risk factors of maternal VAD during pregnancy, and the research findings of the effects of maternal VAD during pregnancy on offspring neurodevelopment based on both human studies and animal experiments, and the possible underlying mechanisms by which maternal VAD affects the development of embryonic layers, brain structures, hippocampal synaptic transmission, and the biological clock in offspring.

Small molecule regulator against circadian rhythm disorder:research advances / 国际药学研究杂志

The circadian rhythm maintains various physiological functions of our body, and regulates the body to cope with the external environment. The disorder in the circadian rhythm could produce harmful effects and increase the risk of diseases. A grow ing research has shown that many small molecule regulators could target the circadian rhythm system, and many new techniques and strategies, including the high-throughput screening technique, have been used in the discovery and investigation of new small mole cule regulators of the circadian rhythm system. In this review, we introduce basic components and molecular mechanisms of the circa dian rhythm system, summarize research progresses in the small molecule regulators, explain the relationship between various chronic diseases and circadian clocks, and discuss potential applications of the small molecule modulators in the treatment of circadian rhythm-related diseases.

Alterations of the circadian rhythm in Parkinson's disease / 中国实用内科杂志

Many physiological activities including endocrine, metabolism and immunity are regulated by circadian rhythm. Abnormal circadian rhythms are associated with a variety of diseases, including tumer, obesity, diabetes and mood disorders, as well as neurodegenerative diseases. Parkinson's disease is the second most common neurodegenerative disease, second only to Alzheimer's disease. The cardinal features of Parkinson's disease include rest tremor, bradykinesia, rigidity, and gait impairment, which are also accompanied by many non-motor symptoms. Circadian dysfunction is one of the most common non-motor symptoms of Parkinson's disease, which may occur before the onset of motor symptoms or last throughout the course of the disease, causing significant negative effects on the quality of life of patients and caregivers. In this article we review the clinical manifestations, biological markers and current treatment strategies of circadian dysfunction in Parkinson's disease.

Envejecimiento y metabolismo: cambios y regulación

Los estudios sobre los efectos del envejecimiento en la fisiología y el metabolismo cada vez son más, uno de sus objetivos es contribuir a instrumentar programas para mejorar la calidad de vida y prevenir discapacidades en la vejez. Es de gran importancia mencionar que durante el envejecimiento se presenta una desaceleración natural del metabolismo, se produce una serie de cambios en la regulación de la energía, lo que contribuye a la pérdida de peso y grasa; estos cambios en la regulación de la ingesta calórica contribuyen en un aumento de la susceptibilidad al desequilibrio energético tanto positivo como negativo, lo cual va asociado a un deterioro en la salud. Sin embargo, el llegar a la vejez, no es una sentencia de muerte para el metabolismo, por el contrario, éste puede ser controlado mediante el mantenimiento de un estilo de vida activo, aunado a esto investigaciones han demostrado que el metabolismo puede ser regulado mediante el papel que desempeña un sistema de reloj sincronizado (ritmos biológicos), el cual a su vez es modulado por varias proteínas reguladoras; esta relación garantiza que las células funcionen correctamente y por tanto el mantenerse saludables. El objetivo de esta revisión es aportar información actualizada sobre la regulación metabolismo-energía y su relación con la gran variedad de componentes involucrados en el gasto energético que acompañan al envejecimiento; analizar la regulación de este sistema para mejorar la calidad de vida y mantener la salud en la vejez.

Aging and metabolism: changes and regulation. Studies about the effects of aging in the physiology and metabolism are increasingly, one of its objectives is to help implement programs to improve the quality of life and prevent disability in elderly. It is relevant to mention that, during aging, there is a natural metabolic deceleration, a series of changes in the regulation of energy are produced, which contributes to loss of weight and fat; the changes in the regulation of caloric intake contribute to increase the susceptibility to energy imbalance both positive and negative, which is associated with a deterioration in health. However, to grow old, is not a death sentence for metabolism, on the other hand, it can be controlled by maintaining an active lifestyle, coupled with this, research has shown that the metabolism can be regulated by a synchronized clock (circadian rhythms), which is mediated by regulatory proteins, this relationship ensures the proper functioning of the cells and therefore good health. The aim of this review is to provide updated information on the energy- metabolism-regulation and its relationship with the great variety of components involved in energy expenditure that accompany aging, to analyze the regulation of this system to improve the quality of life and maintenance of health in old age.

The effect of different illumination condition on drosophila circadian rhythm and 24 h sleep time / 国际中医中药杂志

Objective To investigate the influence of illumination changes on the drosophila circadian rhythm and 24 h sleep time.Methods We collect the unmated fruit flies (a total of 128,single-sex) under CO2 anesthesia within 8 hours of eclosion.And put them into the group of normal light group,day and night reversed group,24 h light group and 24 h dark group with the simple random sampling method,male and female with 4 single-sex groups(n=32).Change the illumination conditions of the living environment of the fruit flies and use Drosophila Activity Monitoring System (DAMS) and Data Acquisition System (DAS),to observe and compare the changes of drosophila circadian rhythm and 24 h sleep time between the different illumination conditions.Results Compared with the normal light group,drosophila circadian rhythm of the day and night reversed group was significantly reversed,the number of fruit flies' activities of 24 h light group was increased,and circadian rhythm was decline,drosophila circadian rhythm of the 24 h dark group is still there,but frequent activity appears during the day,and the 19 : 00 activity peak disappears.Conclusion The drosophila circadian rhythm and 24 h sleep time changes with illumination conditions change.

La desincronización interna como promotora de enfermedad y problemas de conducta / Internal desynchrony as promotor of disease and behavioral disturbance

Life on our planet is ruled by a temporary structure that governs our activities, our days and our calendars. In order to cope with a daily changing environment, organisms have developed adaptive strategies by exhibiting daily behavioral and physiological changes. Biological rhythms are properties conserved in all the levels of organization, from unicellular to prokaryotes to upper plants and mammals. A biological rhythm is defined as the recurrence of a biological phenomenon in regular intervals of time. Biological rhythms in behaviour and physiology are controled by an internal clock which synchronizes its oscillations to external time cues that have the capacity to adjust the clock's mechanism and keep it coupled to external fluctuations. The suprachiasmatic nucleus (SCN) of the hypothalamus in mammals is the master circadian clock which is mainly entrained by the light-dark cycle. The SCN transmits time signals to the brain and then to the whole body and by means of its time signals the SCN keeps a temporal order in diverse oscillations of the body and adjusted to the light-dark cycle. The correct temporal order enables an individual to adequate functioning in harmony with the external cycles. Biological rhythms have a hereditary character, thus its expression is genetically determined. All animals, plants, and probably all organism show some type of physiological rhythmic variation (metabolic rate, production of heat, flowering, etc.) that allow for the adaptation to a rhythmic environment. Biological rhythms enable individuals to anticipate and to be prepared to the demands of the prominent cyclic environmental changes, which are necessary for survival. Also, biological rhythms promote showing maximum levels of a physiological variable at the right moment when the environment requires a maximal response. In humans, an example of circadian rhythms is the sleep-wake cycle; simultaneously, a series of physiological changes are exhibited, also with circadian characteristics (close to 24 hours). Circadian oscillations are observed in the liberation of luteinizant hormone, in plasma cortisol, leptin, insulin, glucose and growth hormone just to mentions some examples. The SCN controls circadian rhythmicity via projections to the autonomic system and by controlling the hypothalamus-adenohipofisis-adrenal axis. In this way, the SCN transmits phase and period to the peripheral oscillators to maintain an internal synchrony. Modern life favors situations that oppose the time signals in the environment and promote conflicting signals to the SCN and its effectors. The consequence is that circadian oscillators uncouple from the master clock and from the external cycles leading to oscillations out of synchrony with the environment, which is known as internal desynchronization. The consequence is that physiological variables reach their peak expression at wrong moments according to environmental demands leading then to deficient responses and to disease in the long run. Also, levels of attention, learning and memory reach peak expression at wrong moments of the day leading individuals to exhibit a deficient performance at school or work. The disturbed sleep patterns promote fatigue and irritability, which difficult social interaction. Internal desynchronization results from transmeridional traveling for which people pass multiple hourly regions. This results in an abrupt change in the time schedule and a syndrome known as <>. Frequent travelers complain about difficulties to adjust their sleep-wake cycle to the new schedule, thus resulting in fatigue, increased sleepiness and reduced attention. Jet lag results from a loss of synchrony among biological rhythms and among diverse functions, which remain out of phase with the day-night cycle. This <> is the cause of general discomfort, decrement in the physical and mental performance, as well as irritability and depression. Frequently, gastrointestinal disorders are a by-product of food consumption at an unusual schedule. The state of internal desynchrony is transitory and depends on the number of time zones that were crossed; thus, adaptation to a new external cycle can take from four to seven days. Another example of internal desynchrony is observed in individuals exposed to work shifts or to nocturnal work schedules (night work). In such conditions, circadian fluctuations in behavioral, hormonal and metabolic parameters are observed but their temporary relation with the external cycles is modified. The internal synchrony is thus affected by troubled environmental signs, out of phase with the daily activities of the individual; among them are the hours of food intake, the exposure to light during resting hours, the low temperature of the night, and the forced activity when homeostatic processes indicate a need to rest. This internal desynchrony leads to gastrointestinal disorders, disturbed metabolic fluctuations, disturbed cardiovascular functions, altered menstrual cycle, sleep disorders, sleepiness, increase of work accidents, etc. Internal desynchrony is especially due to the fact that circadian fluctuations are influenced by daily external cycles, but also by homeostatic factors, and can suffer from additional disturbance by sleep deprivation. Despite years of night work experience, incapacity to adapt to night work may persist. Only a minority of shift workers achieve spontaneous adjustment of the rhythms of core body temperature, melatonin, cortisol, thyroid stimulating hormone, or prolactin secretion to shifts by nocturnal work. Therefore shift and night workers develop a propensity to smoke, drink alcoholic beverages and use stimulant products. After five years of shift or night work, health problems appear with a higher incidence than in the general population. The growing social demand of shift work makes it necessary to decide on the characteristics and forms of shifts to carry out, and up to now organizing such working schedules remaing a serious problem. The improvement of health services has increased life expectancies and thus the general population is becoming old and people survive more years. Older people ail from health and behavioral problems including a deterioration of the biological rhythms. Main alterations consist of a loss of expression of the circadian functions or a decrease of the amplitude of the rhythms, and instability of synchronization mechanisms day by day. All in all, this implies a decreased capacity of the clock to adjust to the solar day. The decreased efficacy of the aging biological clock is evident in the fragmented sleep patterns and the disturbed sleep/wake rhythms, characterized by short sleep episodes during the day and decreased sleep during the night. Some studies suggest that the disturbed circadian rhythms may be the cause of diverse diseases associated with the elderly. In conclusion, during the last 100 years we have changed our lifestyle so radically that we lack already a physiological design to adapt so quickly to modernity. We can state that our body is designed for a world that does not exist. In this article we present a review of the main alterations of the biological rhythms generated by the transmeridional trips, shift-work and aging, their behavioral and physiological consequences that lead to disease and poor mental performance. We also discuss possible strategies that need to be explored and that may help people to improve their quality of life and to prevent internal desynchrony.

La vida se rige por una estructura temporal que gobierna nuestras horas, nuestros días y nuestros calendarios. Como parte de la adaptación a los ciclos de tiempo que impone el planeta, todo organismo presenta ritmos en su actividad y fisiología. Los ritmos biológicos son una propiedad conservada en todos los niveles de organización, desde organismos unicelulares procariontes hasta plantas superiores y mamíferos. De ellos, los más sólidos son aquellos asociados a los ciclos externos por la alternancia del día y la noche y por la alternancia de las estaciones del año. Los ritmos biológicos fisiológicos y conductuales son procesos dependientes de un reloj interno capaz de ajustar sus oscilaciones a claves de tiempo externas que lo mantienen sincronizado a estas fluctuaciones externas. El núcleo supraquiasmático del hipotálamo (NSQ) es en los mamíferos el principal reloj circadiano y se sincroniza principalmente por el ciclo luz-oscuridad. El NSQ transmite señales de tiempo al cerebro y de ahí al resto del organismo, y por medio de estas señales de tiempo mantiene un orden temporal en diversas funciones del cuerpo y las mantiene ajustadas al ciclo luz-oscuridad. El correcto orden temporal interno permite un adecuado funcionamiento del individuo en armonía con el medio externo y le permite exhibir respuestas adecuadas a un ambiente cambiante y predecible. El estilo de vida del hombre moderno propicia situaciones que llevan a alteraciones de nuestros ritmos biológicos que causan una desadaptación temporal, que a su vez redunda en daños a la salud, ya que afecta tanto la fisiología como la forma en que organizamos nuestra conducta. Un ejemplo de ello son los viajes a través de múltiples regiones horarias. Estos cambios de horario bruscos provocan un síndrome conocido como jet-lag, que consiste en un conflicto transitorio entre el tiempo <> y el tiempo <>, lo cual se denomina <>. El jet-lag se define como un conjunto de síntomas causados por una alteración del patrón de sueño, y de la expresión de ritmos biológicos fuera de fase entre sí y fuera de fase con el ciclo del día y la noche. Esta es la causa del malestar general, el deterioro del desempeño mental y físico, así como de la irritabilidad y depresión. Son frecuentes también las alteraciones gastrointestinales, resultado del consumo de alimento en un horario inusual. Otro ejemplo de alteraciones en los ritmos circadianos se observa en los trabajadores con turnos rotatorios o en turnos nocturnos. En estas condiciones se produce un conflicto entre las señales temporales asociadas al ciclo diurno y que transmite el reloj con las actividades y alimentos del trabajador en turnos. De este esquema de trabajo resulta una reducción de las horas de sueño y una alteración de los ritmos circadianos, que llevan a una desincronización interna. Ésta, al igual que en el caso del jet-lag, redunda en un deterioro de las funciones mentales y de la capacidad de atención y memorización, que se asocian a irritabilidad y problemas emocionales. Además, se observan consecuencias en la salud con incremento en la incidencia de malestares gastrointestinales, enfermedades cardiovasculares, obesidad y diabetes. La mejoría en los servicios de salud ha incrementado las expectativas de vida, lo que entonces enfrenta a la humanidad a una población que logra sobrevivir muchos años de su vejez con los cambios de conducta y salud propios de su edad, entre los que se incluye un deterioro de los ritmos biológicos. En este trabajo presentamos una revisión de las principales alteraciones de los ritmos biológicos generadas por los viajes transmeridionales, la vejez y el trabajo en turnos. También discutimos la relevancia de una buena adaptación de los ritmos biológicos y las consecuencias conductuales y fisiológicas que por su alteración llevan a la enfermedad y a un desempeño mental deficiente. También sugerimos estrategias que necesitan ser exploradas y que podrían ayudar prevenir la desincronización interna para mejorar la calidad de vida.

Sincronización no-luminosa: ¿otro tipo de sincronización? Primera parte

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SUMMARY One of the most important functions in which the circadian system participates is to assess that the behavioural and physiological variables adjust appropriately to daily events in the environment, a process referred to as entrainment. Since in the nature the food disposition and predators' activity also are cyclical, the temporary relation between the circadian rhythm and periodic environmental signals maximizes the survival of each species in its temporary niche. Thus, through this mechanism, the organisms adapt to their environment through circadian system which entrain the organism activities to different external signals. In nature environments the predominance of photic entrainment like primary zeitgeber of the biological clock (suprachiasmatic nucleus) is a clear adaptation to the earthly life; nevertheless other biological advantages can be conferred to an individual if the circadian system also is sensible to other environmental signals that they provide from the external time. In such way, the light is not the only synchronizer affecting the biological clock. Other stimuli like the temperature and locomotor activity induced by novel stimuli and certain drugs are also able to entrain the biological clock. These signals have been described like non-photic stimuli. The general effects of the non-photic signals are able to generate phase response and entrain a free running rhythm, only during the subjective day, time in which the biological clock is sensible to these signals which are able to generate phase advances. These phase response are of great magnitude, even of greater magnitude than the induced ones by a light signal. The non-photic signals are also able to induce residual effects (after-effects) on entrainment process, thereby generating changes in the endogenous period, therefore affecting the phase angle in a cycle L:O and promoting the development of locomotor activity rhythm splitting. Furthermore, the light entrainment has been characterized in a wide variety of diurnal and nocturnal species. While, the non-photic entrainment only appears in nocturnal rodents. Being the hamster's biological clock one of that responds to the greater number of biological non-photic signals such as the acute exposition to sexual odors, social interactions, as well as by simple injection of saline solution, all of these non-photic signals are able to induce phase advances of the locomotor activity rhythm in free running when they are applied onto the subjective day. The entrainment to a non-photic stimulus is also observed in humans. Among the non-photic stimuli we can have the pharmacological treatments, social stimuli, stress, food restriction and communication between mother and product in the foetal and neonatal life. These later stimuli are of a particular importance to optimize the circadian function and sensitize the newborn to external environment. Thus the non-photic stimuli could be categorized like behavioural or pharmacological stimuli. These manipulations involve an increase in the locomotor activity, excitation or states able to phase resetting the circadian clock and peripheral oscillators in different species. The non-photic stimuli can affect to the biological clock through an afferent projection from the SCN that translate the non-photic information and is able to induce phase responses. Additionally, non-photic stimuli could also affect the biological clock through the action of a peripheral oscillator, which is sensitive to this type of signals. These peripheral oscillators translate the non-photic information and it communicates with the SCN, through synaptic and no-synaptic mechanisms. With regard to the physiological mechanisms involved on this process, there has been suggested to participate four neurotransmitter systems in the circadian system: a) the serotonergic system originating from the raphe nucleus, b) the NPY system from the leaflet intergeniculate (IGL), c) the GABAergic system, which it is present in most of the neurons of the SCN and IGL (the afferent projections of the raphe and the IGL nucleus make synapse with GABAergic neurons in the SCN) and 4) finally a neural system involving dopamine and melatonin signals, which have been importantly implicated in the brain in the foetal and neonatal live. In comparison to the cascade of intracellular signals caused by glutamatergic stimulation associated to photic entrainment, which excites to the SCN cells, the transmitters implicated in the nonphotic entrainment typically inhibit the SCN neurons. For example the melatonin's main action on the SCN neurons is inhibiting adenylyl cyclase and the translation of related signals driven by the AMPc, such inhibition of activity of the protein kinase depended of AMPc (PKA), which give rise to a decreased phospho- rylation of the transcription factor CREB. In this way, the phase responses induced by non-photic stimuli are not associate with the phosphorylation of the transcription factor (CREB) associated to responsive DNA-elements to binding AMPciclic or with the transcription of early expression genes in the SCN, events of metabothrophic signalling pathway of the photic entrainment. The phase responses generated by the non-photic signals occur during the subjective day, time in which the spontaneous expression of clock genes is high in diurnal and nocturnal animals. A reason why the phase resetting of biological clock to non-photic signals can be generated by a fast suppression in the expression levels of the genes clock. The decrease of Per1 and Per2 messenger RNA's expression levels in the SCN generated by non-photic stimuli occurs during a half of the subjective day, not during the subjective night, which suggests that these genes may participate in the phase resetting of biological clock during the subjective day. The interactions between phase response induced by the light and those induced by non-photic stimuli have been described previously. When a photic stimulus is applied after a non-photic signal during subjective day, with the purpose of studying the interaction between photic stimuli and non-photic stimuli, the photic stimulus blocks or attenuates the phase advances generated in response to different non-photic stimuli applied, such as the forced locomotor activity, sleep privation, NPY administration, or serotonergic agonists (8-OH-DPAT) administration. If the genes clock responds to the non-photic stimuli, then the lack of some of them will have to generate alterations in the response to non-photic signals. In the Clock mutant mice, the biological clock responses to the non-photic signals applied during the subjective day generate phase responses in opposed direction from those generated by intact subjects. This latter suggests that different genes clock participate in the generation of the phase response to a non-photic stimulus. The non-photic entrainment of the circadian system has a biological and/or social importance in several contexts. In the early products life, the communication of circadian information from the mother is important in regulating the biological clock of the foetus or newborn before they are sensitive to light. Under circumstances where the social and work routines are altered, by changes of constant "work turn" (shift work), the biological clock receives photic and non-photic signals which generate a dysfunction and poor work efficiency. The absence of non-photic signals followed by a social abstinence can induce alterations in the mental health (depression). The sleep disorder, experimented blind subject can arise from a lost of the social entrainment, therefore a decrease in the efficiency of the clock mechanism. Thus latter alterations of the clock, it could be possible to develop new forms of pharmacological and behavioural treatments.