Effects of long-term noise exposure during sleep on liver circadian clock and lipid metabolism / 环境与职业医学

Background Long-term exposure to noise during sleep may has adverse effects on metabolic system, and liver lipid metabolism is closely related to circadian clock genes. Objective To investigate the effects of long-term noise exposure during sleep on liver circadian clock and lipid metabolism in mice and its related mechanism. Methods Twenty C57BL/6J male mice were randomly divided into two groups: a noise exposure group and a control group with 10 mice in each group. The mice in the noise exposure group were exposed to white noise at 90 dB sound pressure level (SPL) for 30 consecutive days, 8 h a day, from 9:00 to 17:00. The mice in the control group were exposed to background noise ≤40 dB SPL. After noise exposure, the animals were neutralized at 14:00 (ZT6) and 2:00 (ZT18), 5 animals at each time spot, and the liver tissues were collected. Total cholesterol and triglyceride in liver were determined by cholesterol oxidase method and glycerol phosphate oxidase method respectively. The expressions of circadian clock genes (Clock, Bmal1, Rev-erbα, and Rev-erbβ) and lipid metabolism genes (Srebp1c, Hmgcr, Fasn, Lxrα, Acc1, and Chrebp) in liver were detected by quantitative real-time PCR. Results Compared with the control group, the content of total cholesterol in liver in the noise exposure group increased by 48% (P<0.05) and the content of liver triglyceride increased by 61% (P<0.05) at ZT18. The mRNA expression levels of circadian clock genes Clock and Bmal1 in the noise exposure group was significantly increased at ZT18 and decreased at ZT6 (P<0.05). The mRNA expression level of Rev-erbα decreased at both ZT6 and ZT18 (P<0.05). The mRNA expression level of Rev-erbβ had no significant change at ZT6 and ZT18. The mRNA expression levels of liver lipid metabolism related genes Srebp1c, Hmgcr, Chrebp, and Lxrα in the noise exposure group were higher than those in the control group at ZT18 (P<0.05). The mRNA expression levels of Acc1 and Fasn showed no significant change at ZT6, then an upward trend at ZT18, but no significant difference between the two time spots (P>0.05). Conclusion Long-term noise exposure during sleep can cause circadian clock and lipid metabolism disorders in mice. Among them, suppression of key circadian clock genes may be associated with Rev-erbα-mediated upregulation of the nuclear receptors Srebp1c and Chrebp for lipid synthesis and deposition in the liver, resulting in lipid metabolism disorder.

Difference in ketone bodies levels between diurnal and nocturnal fasting in children: observational study

Introduction Children are susceptible to developing preoperative ketonemia, which can be affected by changes in the circadian rhythm and counter-regulatory hormones. It is unclear whether ketonemia depends on the timing of fasting. Objective To assess the effect of preoperative fasting time (diurnal vs. night) on the preoperative concentration of ketone bodies in children. Methods We conducted a prospective-observational clinical study between September 2020 and March 2021, including children under 48 months of age scheduled for elective surgery. Two groups were identified based on fasting time, as follows: diurnal fasting (group A, n = 40) and nocturnal fasting (group B, n = 52). Demographic data, duration of fasting, time of excess fasting, type of food intake, the concentration of ketone bodies and capillary blood glucose, level of anxiety, and dehydration were analyzed in both groups. Results Diurnal fasting was associated with higher incidence of ketonemia compared with nocturnal fasting (Group A: 62.5% (95% CI 48.1-82.0); group B: 38,5% (95% CI 26.5-52.5), P=0.02). Most of the patients exceeded the duration of fasting recommended by preoperative fasting guidelines (95.6%). The type of food eaten before surgery was significantly associated with the presence of ketonemia (P=0.01). Conclusions Preoperative ketonemia is relatively common in patients under 48 months of age, especially among those who undergo diurnal fasting compared to nocturnal fasting.

Introducción Los niños son susceptibles a desarrollar cetonemia preoperatoria que puede verse afectada por cambios en el ritmo circadiano y las hormonas contrarreguladoras. No está claro si la cetonemia depende de la hora del ayuno. Objetivo Evaluar el efecto del momento del ayuno preoperatorio (diurno vs. nocturno) sobre la concentración preoperatoria de los cuerpos cetónicos en niños. Métodos Llevamos a cabo un estudio clínico observacional entre septiembre de 2020 y marzo de 2021, en niños menores de 48 meses, programados para cirugía electiva. Se identificaron dos grupos basados en la hora del ayuno, como sigue: ayuno diurno (grupo A, n = 40) y ayuno nocturno (grupo B, n = 52). En ambos grupos se analizaron los datos demográficos, la duración del ayuno, el tiempo excesivo de ayuno, el tipo de ingesta de alimentos, la concentración de cuerpos cetónicos, la glicemia capilar, el nivel de ansiedad y la deshidratación. Resultados El ayuno diurno se asocio con una mayor incidencia de cenotemia en comparación con el ayuno nocturno (Grupo A: 62,5% (IC 95% 48,1-82,0); grupo B: 38,5% (95% CI 26.5-52.5), P=0.02). La mayoría de los pacientes excedieron el tiempo de ayuno recomendado según las guías de ayuno preoperatorio (95,6%). El tipo de alimentos ingeridos antes de la cirugía se asoció de manera importante con la presencia de cetonemia (P=0,01). Conclusiones La cetonemia preoperatoria es relativamente común en pacientes menores de 48 meses de edad, especialmente entre quienes se someten a ayuno diurno en comparación con ayuno nocturno.

Circadian rhythm in prostate cancer: time to take notice of the clock / 亚洲男科学杂志(英文版)

The circadian clock is an evolutionary molecular product that is associated with better adaptation to changes in the external environment. Disruption of the circadian rhythm plays a critical role in tumorigenesis of many kinds of cancers, including prostate cancer (PCa). Integrating circadian rhythm into PCa research not only brings a closer understanding of the mechanisms of PCa but also provides new and effective options for the precise treatment of patients with PCa. This review begins with patterns of the circadian clock, highlights the role of the disruption of circadian rhythms in PCa at the epidemiological and molecular levels, and discusses possible new approaches to PCa therapy that target the circadian clock.

The Circadian System Is Essential for the Crosstalk of VEGF-Notch-mediated Endothelial Angiogenesis in Ischemic Stroke / 神经科学通报·英文版

Ischemic stroke is a major public health problem worldwide. Although the circadian clock is involved in the process of ischemic stroke, the exact mechanism of the circadian clock in regulating angiogenesis after cerebral infarction remains unclear. In the present study, we determined that environmental circadian disruption (ECD) increased the stroke severity and impaired angiogenesis in the rat middle cerebral artery occlusion model, by measuring the infarct volume, neurological tests, and angiogenesis-related protein. We further report that Bmal1 plays an irreplaceable role in angiogenesis. Overexpression of Bmal1 promoted tube-forming, migration, and wound healing, and upregulated the vascular endothelial growth factor (VEGF) and Notch pathway protein levels. This promoting effect was reversed by the Notch pathway inhibitor DAPT, according to the results of angiogenesis capacity and VEGF pathway protein level. In conclusion, our study reveals the intervention of ECD in angiogenesis in ischemic stroke and further identifies the exact mechanism by which Bmal1 regulates angiogenesis through the VEGF-Notch1 pathway.

Effects of shift work on adipokines, inflammatory factors, and insulin sensitivity in non-overweight/obese women / 中华内分泌代谢杂志

Objective:To observe the effect of shift work on the stability of the circadian clock and insulin sensitivity in non-overweight/obese individuals with normal blood glucose, and explore underlying connection.Methods:Female shift working nurses in the Department of Blood Transplantation and non-shift working nurses in the Health Management Center in the First Affiliated Hospital of Zhengzhou University were divided into shift worker group (SW group) and non-shift worker group (NSW group). Serum inflammatory factors [interleukin-6 (IL-6), tumor necrosis factor-α(TNF-α)], adipokines (adiponectin, leptin, chemerin, visfatin), and melatonin levels were measured using enzyme linked immunosorbent assay (ELISA). Realtime fluorescence quantitative PCR was performed to detect peripheral blood circadian clock genes circadian locomotor output cycles protein kaput(Clock) and brain and muscle ARNT-like protein 1(Bmal1). Cortisol and fasting insulin were measured by chemiluminescent microparticle immunoassay, and HbA 1C was measured by capillary electrophoresis. In addition, visceral fat area (VFA) was assessed with bioelectrical impedance analyzer, and mid-sleep time composite phase deviations (CPD) was calculated based on the International Physical Activity Short Questionnaire. Results:SW group had lower serum level of melatonin ( P=0.023) and higher cortisol ( P=0.001) than the NSW group, and altered mRNA expression of Clock and Bmal1 ( P=0.034, P=0.047). Fasting blood glucose and HbA 1C in the SW group, although in the normal range, had been higher than in the NSW group ( P=0.011, P=0.033). Although body mass index was normal in SW group, VFA had been higher than that of the NSW group ( P=0.010). And homeostasis model assessment for insulin resistance (HOMA-IR), IL-6, TNF-α, leptin, chemerin, and visfatin were significantly higher in the SW group than NSW group ( P=0.033, P=0.012, P=0.001, P=0.011, P=0.021, P=0.007). In addition, adjusting for body mass index and activity factors revealed a significant positive correlation between CPD and VFA ( r=0.434, P=0.049), inflammatory factors IL-6 ( r=0.514, P=0.017) and TNF-α ( r=0.700, P<0.001) and pro-inflammatory adipokines leptin ( r=0.473, P=0.030), chemerin ( r=0.439, P=0.047), visfatin ( r=0.521, P=0.015). Conclusion:Shift work can affect circadian clock, with increased visceral adiposity, pro-inflammatory adipokines, inflammatory factors and decreased insulin sensitivity in women without overweight/obese.

Effect of Jiangtang Xiaozhi Tablet on Liver Circadian Clock-related Genes CLOCK， BMAL1， REV-ERBα， and REV-ERBβ in Mice with Metabolic Dysfunction-associated Fatty Liver Disease / 中国实验方剂学杂志

ObjectiveTo explore the effect of Jiangtang Xiaozhi tablet （JTXZT） on metabolic dysfunction-associated fatty liver disease and to study the mechanism from the perspective of circadian clock-related genes such as circadian locomotor output cycles kaput （CLOCK）， brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein 1 （BMAL1）， reverse-eritroblastosis receptor （REV-ERB）α and β. MethodA total of 50 male SPF C57BL/6J mice were randomized into normal group （n=10） and modeling group （n=40）. The normal group was fed with normal diet， and the modeling group with high-fat diet for 4 weeks. Then the model mice were randomly classified into model group， high-dose （12.5 g·kg-1） and low-dose （6.25 g·kg-1） Jiangtang Xiaozhi tablet groups， and orlistat group （70 mg·kg-1）， with 10 mice in each group. The normal group and model group received equivalent volume of distilled water （8 weeks）. Then， the body weight of mice was measured， and the content of serum triglyceride （TG）， total cholesterol （TC）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）， aspartate aminotransferase （AST）， and alanine aminotransferase （ALT） was determined with biochemical method. Serum content of free fatty acid （FFA） and leptin was detected by enzyme-linked immunosorbent assay （ELISA）. Pathological changes of liver tissue and epididymal adipose tissue were observed based on hematoxylin-eosin （HE） staining. Liver fibrosis was examined based on Masson's trichrome staining， and changes of lipids based on oil red O staining. The expression of CLOCK， BMAL1， REV-ERBα， and REV-ERBβ was detected by Western blot and immunohistochemistry assay. ResultCompared with the normal group， the model group had high content of TG， TC， LDL-C， HDL-C， AST， ALT， FFA， and leptin （P<0.05， P<0.01）， showed ballooning degeneration and focal microvesicular steatosis of liver cells， enlarged adipocytes， and inflammatory cell clusters and fibrous tissue hyperplasia， and displayed increased protein expression of sterol regulatory element binding protein （SREBP） 1 and peroxisome proliferators-activated receptor （PPAR）γ （P<0.01） and decreased protein expression of PPARα （P<0.05）， CLOCK， BMAL1， REV-ERBα and β （P<0.05， P<0.01）. Compared with the model group， JTXZT-H group down-regulated the content of TG， TC， LDL-C， HDL-C， AST， ALT， FFA， and leptin in mice （P<0.05， P<0.01）， and the JTXZT groups demonstrated reduction in the degree and range of ballooning degeneration of liver tissue， alleviation of the compression of hepatic sinusoidal tissue， unobvious inflammatory cell infiltration and fibrous tissue proliferation， reduction in the expression of SREBP1 and PPARγ （P<0.05， P<0.01）， and rise of the protein expression of PPARα （P<0.01）， CLOCK， BMAL1， REV-ERBα， and REV-ERBβ （P<0.05， P<0.01）. ConclusionJTXZT can significantly alleviate the metabolic dysfunction-associated fatty liver disease in mice caused by high-fat diet. The mechanism is the likelihood that it regulates downstream related lipid metabolism proteins （such as SREBP1， PPARγ， and PPARα）.

Effect of Jiangtang Xiaozhi Tablet on Liver Circadian Clock-related Genes CLOCK， BMAL1， REV-ERBα， and REV-ERBβ in Mice with Metabolic Dysfunction-associated Fatty Liver Disease / 中国实验方剂学杂志

ObjectiveTo explore the effect of Jiangtang Xiaozhi tablet （JTXZT） on metabolic dysfunction-associated fatty liver disease and to study the mechanism from the perspective of circadian clock-related genes such as circadian locomotor output cycles kaput （CLOCK）， brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein 1 （BMAL1）， reverse-eritroblastosis receptor （REV-ERB）α and β. MethodA total of 50 male SPF C57BL/6J mice were randomized into normal group （n=10） and modeling group （n=40）. The normal group was fed with normal diet， and the modeling group with high-fat diet for 4 weeks. Then the model mice were randomly classified into model group， high-dose （12.5 g·kg-1） and low-dose （6.25 g·kg-1） Jiangtang Xiaozhi tablet groups， and orlistat group （70 mg·kg-1）， with 10 mice in each group. The normal group and model group received equivalent volume of distilled water （8 weeks）. Then， the body weight of mice was measured， and the content of serum triglyceride （TG）， total cholesterol （TC）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）， aspartate aminotransferase （AST）， and alanine aminotransferase （ALT） was determined with biochemical method. Serum content of free fatty acid （FFA） and leptin was detected by enzyme-linked immunosorbent assay （ELISA）. Pathological changes of liver tissue and epididymal adipose tissue were observed based on hematoxylin-eosin （HE） staining. Liver fibrosis was examined based on Masson's trichrome staining， and changes of lipids based on oil red O staining. The expression of CLOCK， BMAL1， REV-ERBα， and REV-ERBβ was detected by Western blot and immunohistochemistry assay. ResultCompared with the normal group， the model group had high content of TG， TC， LDL-C， HDL-C， AST， ALT， FFA， and leptin （P<0.05， P<0.01）， showed ballooning degeneration and focal microvesicular steatosis of liver cells， enlarged adipocytes， and inflammatory cell clusters and fibrous tissue hyperplasia， and displayed increased protein expression of sterol regulatory element binding protein （SREBP） 1 and peroxisome proliferators-activated receptor （PPAR）γ （P<0.01） and decreased protein expression of PPARα （P<0.05）， CLOCK， BMAL1， REV-ERBα and β （P<0.05， P<0.01）. Compared with the model group， JTXZT-H group down-regulated the content of TG， TC， LDL-C， HDL-C， AST， ALT， FFA， and leptin in mice （P<0.05， P<0.01）， and the JTXZT groups demonstrated reduction in the degree and range of ballooning degeneration of liver tissue， alleviation of the compression of hepatic sinusoidal tissue， unobvious inflammatory cell infiltration and fibrous tissue proliferation， reduction in the expression of SREBP1 and PPARγ （P<0.05， P<0.01）， and rise of the protein expression of PPARα （P<0.01）， CLOCK， BMAL1， REV-ERBα， and REV-ERBβ （P<0.05， P<0.01）. ConclusionJTXZT can significantly alleviate the metabolic dysfunction-associated fatty liver disease in mice caused by high-fat diet. The mechanism is the likelihood that it regulates downstream related lipid metabolism proteins （such as SREBP1， PPARγ， and PPARα）.

Co-regulation of circadian clock genes and microRNAs in bone metabolism / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Mammalian bone is constantly metabolized from the embryonic stage, and the maintenance of bone health depends on the dynamic balance between bone resorption and bone formation, mediated by osteoclasts and osteoblasts. It is widely recognized that circadian clock genes can regulate bone metabolism. In recent years, the regulation of bone metabolism by non-coding RNAs has become a hotspot of research. MicroRNAs can participate in bone catabolism and anabolism by targeting key factors related to bone metabolism, including circadian clock genes. However, research in this field has been conducted only in recent years and the mechanisms involved are not yet well established. Recent studies have focused on how to target circadian clock genes to treat some diseases, such as autoimmune diseases, but few have focused on the co-regulation of circadian clock genes and microRNAs in bone metabolic diseases. Therefore, in this paper we review the progress of research on the co-regulation of bone metabolism by circadian clock genes and microRNAs, aiming to provide new ideas for the prevention and treatment of bone metabolic diseases such as osteoporosis.

Effects of circadian misalignment induced by abnormal photoperiod on expression rhythm of clock genes and glucose uptake related genes in gastrocnemius in rats / 中国康复理论与实践

ObjectiveTo investigate the impacts of circadian misalignment on glucose uptake of skeletal muscle and metabolism in rats. MethodsA total of 36 male Wistar rats were divided into circadian alignment (CA, normal light-dark cycles, n = 18) and circadian misalignment (CM, shifted light-dark cycles, n = 18) groups. ClockLab behavior analysis was performed for 18 days (61 to 78 days after modeling). Intraperitoneal injection glucose tolerance test and physiologic measures were performed 85 days after modeling. They were euthanized 91 to 92 days after modeling, at 8:00, 12:00, 16:00, 20:00, 24:00 and 4:00 next day. Gastrocnemius tissue was collected and measured for Bmal1, Clock, Per2, Tbc1d1, Glut4 and Pgc1α by reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR). ResultsThe circadian cycle increased (t = -6.557, P < 0.001), the amplitude decreased (t = 2.326, P = 0.030) and the area under curve (AUC) of the blood glucose of intraperitoneal glucose tolerance test decreased (t = -2.622, P = 0.016) in CM group. In gastrocnemius, there was difference in the expression of the Bmal1 (F = 6.691, P < 0.001), Clock (F = 4.188, P = 0.007), Per2 (F = 10.893, P < 0.001), Tbc1d1 (F = 3.411, P = 0.018), Glut4 (F = 5.439, P = 0.002) and Pgc1α (F = 15.376, P < 0.001) across different time; meanwhile, there was difference in the expression of Bmal1 (F = 5.020, P = 0.035), Per2 (F = 8.996, P = 0.006), Tbc1d1 (F = 51.111, P < 0.001) and Pgc1α (F = 10.177, P = 0.004) between groups, and the total Tbc1d1 expression decreased in CM group (t = 4.349, P < 0.001). ConclusionCM induced by shifted light-dark cycles may lead to glucose tolerance impairment in rats, which may be related to the decreased expression of Tbc1d1 and the changes of transcription rhythm of Bmal1, Per2 and Pgc1α in gastrocnemius.

The effects of miRNA-155-5p and the circadian clock gene Bmal1 on proliferation and aging in mouse bone marrow mesenchymal stem cells / 口腔疾病防治

Objective@#To investigate the effect of brain and muscle arant-like-1 (Bmal1) and miRNA-155-5p on the proliferation ability and aging of bone marrow mesenchymal stem cells (BMMSCs) to provide an experimental basis for elucidating the mechanism of bone senescence.@*Methods @# BMMSCs were extracted from the femur medullary cavity of 1-month-old mice, purified and cultured via the whole bone marrow mesenchymal adherent method and passed to P3. The characteristics of BMMSCs were detected by flow cytometry. BMMSCs were transfected with lentivirus to construct stable miR-155-5p and Bmal1 overexpression/interference BMMSCs. shRNA-transfected BMMSCs were identified by qRT-PCR. The proliferation activities of miR-155-5p and Bmal1 overexpression/interference BMMSCs were detected via CCK-8 assay. The apoptosis rates were measured by flow cytometry. The aging status of BMMSCs was identified with the senescence-associated β-galactosidase (SA-β-Gal) test. The expression of senescence-related genes P16 and P53 was detected by qRT-PCR.@*Results@#The shRNA-transfected BMMSCs were successfully generated. The proliferation ability decreased, and the apoptosis rates, the activity of SA-β-Gal and the relative expression levels of P53 and P16 increased when miRNA-155-5p was overexpressed. The proliferation ability increased, and the apoptosis rates, the activity of SA-β-Gal and the relative expression levels of P53 and P16 decreased when miRNA-155-5p was inhibited. The effect of Bmal1 is opposite to that of miRNA-155-5p.@*Conclusions @# The expression of Bmal1 promotes the proliferation and antiaging ability of BMMSCs, while miRNA-155-5p inhibits the proliferation and accelerates the aging of BMMSCs.

Roles of the Circadian Clock in Ovarian Physiology and Pathology / 中国生物化学与分子生物学报

The circadian rhythm of mammals is a physiological phenomena that is about 24 hours produced by genetically encoded molecular clocks, making the physiological process of the body coordinated with the changes of the external environment, and it is a manifestation of adaptation to the environment. In mammals, reproductive physiology is regulated by the circadian clock. The expression of circadian clock genes has been observed in each tissue of the hypothalamic-pituitary-ovarian (HPO) axis, and the biological clock at all levels coordinates and synchronizes with each other to maintain normal reproductive behavior. The production, maintenance, and regulation of circadian rhythms depend on a chain of transcription-translation feedback loops (TTLs), which determine the cycle and amplitude of gene expression in each tissue of the HPO axis. The circadian clock of the ovary is regulated by theneuroendocrine regulation of suprachiasmatic nucleus of the hypothalamus, but it is autonomous. Circadian rhythm disruption caused by environmental factors can seriously impair female fertility and lead to a range of related ovarian diseases. In addition, the circadian clock is also closely related to ovarianaging. Based on existing research, this paper focuses on the mechanism of the circadian clock in ovarian follicular development, ovulation and steroid generation, as well as the latest research progress on the relationship between the circadian clock and ovarian aging. In addition, several common ovarian diseases with decreased fertility due to circadian clock disorders are described.

Period circadian clock 3 inhibits palmitic acid-induced oxidative stress and inflammatory factor secretion in podocytes / 中南大学学报(医学版)

OBJECTIVES@#High fat-induced podocyte injury is one of the important factors leading to obesity related nephropathy (ORG), but the mechanism is not clear. This study aims to explore the mechanism of period circadian clock 3 (PER3) in the oxidative stress and inflammation induced by palmitic acid (PA) in podocytes.@*METHODS@#The C57BL/6J mice were fed with chow and high-fat diet for 16 weeks. The PER3 expression in kidney tissues were detected in the normal body weight group and the obesity group. The PER3 mRNA and protein expression were detected after the podocytes were induced with different concentrations (0, 50, 150 and 300 μmol/L) of PA for 48 h. The PER3 mRNA and protein expression were detected after the podocytes were induced with 150 μmol/L PA for 0, 24, 36, and 48 h. Triglyceride (TG) levels were examined in the PA group, the adenovirus (ad)-PER3+PA group, and the siRNA-PER+PA group after the podocytes were transfected by Ad-PER3 or small interfering RNA (siRNA)-PER3 for 48 h and subsequently were induced with 150 μmol/L PA for 48 h. The differential gene expression was detected using RNA sequencing (RNA-seq) after podocytes were transfected by siRNA-PER3 (siRNA-PER3 group) and siRNA-control (siRNA-control group), respectively. The mRNA levels of nephrin, podocin, podocalyxin, podoplanin, superoxide dismutase 1 (SOD1), glutathione peroxidase 1 (GPX1), catalase (CAT), and the levels of malondialdehyde (MDA), glutathione (GSH), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) and interleukin-2 (IL-2) were detected after podocytes were transfected with Ad-PER3 or Ad-control for 48 h and then they were induced by 150 μmol/L PA for 48 h.@*RESULTS@#The PER3 was down-regulated in the obesity group compared with the normal body weight group (@*CONCLUSIONS@#PER3 can decrease the PA-induced oxidative stress and inflammatory factor secretion via inhibiting the lipogenesis in podocytes.

Abnormal Circadian Clock Ｐromotes AOM / DSS-induced Colon Carcinogenesis in Mice by Remodeling Tumor Metabolism / 中国生物化学与分子生物学报

Abnormal circadian clock has been identified as an independent risk factor for tumorigenesis, and is closely related to the occurrence and development of tumor. As metabolic disorder is also one of the important characteristics of tumorigenesis, therefore it is particularly important to investigate the regulatory relationship between biological clock and tumor metabolism. In this study, the effect of abnormal circadian clock on colon cancer growth was evaluated by azoxymethane (AOM) / dextran sodium sulfate (DSS) -induced colitis-associated carcinogenesis (CAC) mice model. The result showed that abnormal circadian clock aggravated anal swelling, redness, bloody and anorectal prolapse in CAC mice, and significantly increased the number and volume of CAC polyps (P <0. 05 or P <0. 01), and reduced the intestinal length, body weight, survival rate of CAC mice and the expression levels of inflammatory factors IL-1β (interleukin-1 beta) and TNFα (tumor necrosis factor α) (P < 0. 05 or P < 0. 01), indicating that abnormal biological clock promotes the occurrence and development of CAC. Further, non-target metabonomics analysis of serum samples from mice was performed by liquid chromatography-mass spectrometry (LC-MS) . The result showed that compared with CAC mice with normal circadian rhythm, 27 differential metabolites were identified in CAC mice with disrupted circadian clock, and 9 metabolic pathways were enriched by KEGG (kyoto encyclopedia of genes and genomes) database. These results suggest that abnormal circadian clock can significantly change the relative abundance of some metabolites in serum samples from CAC mice, remodel tumor metabolism, and result in the development of CAC in mice. This study reveals the pivotal role of tumor metabolism in the abnormal circadian clock promoting the growth of CAC in mice, providing a new experimental basis for the interaction between circadian clock and metabolic homeostasis in the occurrence and development of colon cancer.

Chronopharmacology: A new way to treat disease

Chronopharmacology aims at the use of biological rhythms in the clinical treatment to enhance both effectiveness and tolerance and minimizes the side effects of a drug by determining the best biological time for its administration. It involves bot h the investigation of drug effects as a function of biologic timing and the investigation of drug effects upon rhythm characteristics. Rhythmicity has been detected in several physiological variables such as pulse, temperature, blood pressure and hormonal secretions like diurnal variation insulin effects on blood glucose. The goal of chronopharmacology is to optimize the therapeutic effect and control or reduce the adverse effects without altering the functioning of the drug in the body. Auto-induction, auto- inhibition and food effects are considered to be the reasons of chronopharmacology. The effectiveness and toxicity of many drugs vary depending on dosing time associated with 24 hrs rhythm of biological, physiological and behavioral processes under the control of the circadian clock. Now a day, the chronopharmacological principle is used in the therapy of various diseases such as angina, hypertension, asthma, peptic ulcer, diabetes, migraine, etc. This article aims to introduce chronopharmacology, their terminologies, causes and need of it, biological clock and biological rhythms in various biological systems and the dependence of diseases on biological rhythms.

Progress in the molecular mechanism of KaiA regulating cyanobacterial circadian clock / 生物工程学报

The cyanobacterial circadian clock has three relatively independent parts: the input path, the core oscillator, and the output path. The core oscillator is composed of three clock proteins: KaiA, KaiB, and KaiC. The interactions among these three proteins generate a rhythmic signal and convey the input signals to the output signals to maintain the accuracy and stability of the oscillation of downstream signals. Based on the cyanobacterial circadian clock and the structure, function, and interaction of the clock proteins of the core oscillator, combining the recent results from our laboratory, this review summarized the recent progresses of the molecular mechanism of KaiA in regulating KaiC's enzymatic activity, mediating phase reset of the oscillator, and competing with CikA for the binding site of KaiB.

Nuclear Envelope Protein MAN1 Regulates the Drosophila Circadian Clock via Period / 神经科学通报·英文版

Almost all organisms exhibit ~24-h rhythms, or circadian rhythms, in a plentitude of biological processes. These rhythms are driven by endogenous molecular clocks consisting of a series of transcriptional and translational feedback loops. Previously, we have shown that the inner nuclear membrane protein MAN1 regulates this clock and thus the locomotor rhythm in flies, but the mechanism remains unclear. Here, we further confirmed the previous findings and found that knocking down MAN1 in the pacemaker neurons of adult flies is sufficient to lengthen the period of the locomotor rhythm. Molecular analysis revealed that knocking down MAN1 led to reduced mRNA and protein levels of the core clock gene period (per), likely by reducing its transcription. Over-expressing per rescued the long period phenotype caused by MAN1 deficiency whereas per mutation had an epistatic effect on MAN1, indicating that MAN1 sets the pace of the clock by targeting per.

The connection between the night pain of patients with rotator cuff tears and circadian clock / 医学研究生学报

Patients with rotator cuff tears often have repeated irregular neck and shoulder pain, and all of them are aggravated at night. The patient is very painful and cannot suffer from lateral position. Most of them cannot or do not do the exercises such as stretching the elbow and bending the arm, which seriously affect sleep. Numerous studies have shown that in addition to inflammation, the two-way interaction to the circadian clock, the circadian clock also regulated many aspects of the immune system. And the mechanism of night pain caused by rotator cuff injury was related to factors such as inflammation of the acromion sac. This suggests that the night pain of rotator cuff tears may have a circadian rhythm. This article mainly reviews the mechanism of night pain caused by rotator cuff tears.

Influence of Circadian Disruption Associated With Artificial Light at Night on Micturition Patterns in Shift Workers / 대한배뇨장애요실금학회지

Shift workers often experience problems associated with circadian disruption associated with artificial light at night and nocturia is commonly noted in night-shift workers. Nocturia associated with circadian disruption is due to increased urine production of the kidney and decreased storage function of the bladder. A recent discovery of peripheral clock genes in the bladder and their role in contractile property of the bladder support that micturition is closely related to the circadian rhythm. Moreover, there are clinical studies showed that shift workers more often experienced nocturia due to circadian disruption. However, comparing with other health problems, concerns on nocturia and voiding dysfunction associated with circadian disruption are insufficient. Therefore, further studies about voiding dysfunction associated with the circadian disruption in shift workers are necessary.

Circadian Regulation by REV-ERBα Mediates Hippocampal E-LTP in a Time-dependent Manner

Circadian rhythms are driven by circadian oscillators, and these rhythms result in the biological phenomenon of 24-h oscillations. Previous studies suggest that learning and memory are affected by circadian rhythms. One of the genes responsible for generating the circadian rhythm is Rev-erbα. The REV-ERBα protein is a nuclear receptor that acts as a transcriptional repressor, and is a core component of the circadian clock. However, the role of REV-ERBα in neurophysiological processes in the hippocampus has not been characterized yet. In this study, we examined the time-dependent role of REV-ERBα in hippocampal synaptic plasticity using Rev-erbα KO mice. The KO mice lacking REV-ERBα displayed abnormal NMDAR-dependent synaptic potentiation (E-LTP) at CT12~CT14 (subjective night) when compared to their wild-type littermates. However, Rev-erbα KO mice exhibited normal E-LTP at CT0~CT2 (subjective day). We also found that the Rev-erbα KO mice had intact late LTP (L-LTP) at both subjective day and night. Taken together, these results provide evidence that REV-ERBα is critical for hippocampal E-LTP during the dark period.

The visual basis of the biological clock "sees" the light:intrinsically photosensitive retinal ganglion cells / 中华实验眼科杂志

Mammalian eyes mediate both image-forming and non-image-forming visual functions. Non-image-forming vision provides a measure of the ambient light for the purposes of synchronization of circadian clocks to light/dark cycles and regulation of pupil size,pineal melatonin production and other functions. Traditionally,people used to believe that the classical photoreceptors (rods and cones) regulate both image-forming and non-image-forming visual pathways. However,a small subset of retinal ganglion cells called intrinsically photosensitive RGCs ( ipRGCs) has been identified to be a third type of mammalian photoreceptor and determined to be photosensitive, recently. The discovery of ipRGCs has allowed for rapid progress in the past decade toward understanding the non-image-forming visual system,especially about how the circadian clock complete the synchronization with the light/dark cycle. The anatomical and developmental characteristics of ipRGCs, as well as its biological functions and regulation were reviewed in this paper.