scholarly journals Circadian Clock Component BMAL1 in the Paraventricular Nucleus Regulates Glucose Metabolism

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4487
Author(s):  
Masanori Nakata ◽  
Parmila Kumari ◽  
Rika Kita ◽  
Nanako Katsui ◽  
Yuriko Takeuchi ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Glucose Metabolism ◽  
Glucose Tolerance ◽  
Paraventricular Nucleus ◽  
Clock Gene ◽  
Clock Genes ◽  
Circadian Variation ◽  
Glucose And Lipid Metabolism ◽  
Clock Component

It is suggested that clock genes link the circadian rhythm to glucose and lipid metabolism. In this study, we explored the role of the clock gene Bmal1 in the hypothalamic paraventricular nucleus (PVN) in glucose metabolism. The Sim1-Cre-mediated deletion of Bmal1 markedly reduced insulin secretion, resulting in impaired glucose tolerance. The pancreatic islets’ responses to glucose, sulfonylureas (SUs) and arginine vasopressin (AVP) were well maintained. To specify the PVN neuron subpopulation targeted by Bmal1, the expression of neuropeptides was examined. In these knockout (KO) mice, the mRNA expression of Avp in the PVN was selectively decreased, and the plasma AVP concentration was also decreased. However, fasting suppressed Avp expression in both KO and Cre mice. These results demonstrate that PVN BMAL1 maintains Avp expression in the PVN and release to the circulation, possibly providing islet b-cells with more AVP. This action helps enhance insulin release and, consequently, glucose tolerance. In contrast, the circadian variation of Avp expression is regulated by feeding, but not by PVN BMAL1.

scholarly journals MECHANISMS IN ENDOCRINOLOGY: A sense of time of the glucocorticoid circadian clock: from the ontogeny to the diagnosis of Cushing’s syndrome

2018 ◽  
Vol 179 (1) ◽  
pp. R1-R18 ◽  
Author(s):  
Ayrton Custodio Moreira ◽  
Sonir Rauber Antonini ◽  
Margaret de Castro
Keyword(s):  
Circadian Rhythm ◽  
Circadian Clock ◽  
Clock Genes ◽  
Circadian Variation ◽  
Circadian System ◽  
Feedback Loops ◽  
Adrenal Axis ◽  
Sense Of Time ◽  
Pituitary Adrenal Axis ◽  
Hierarchical Manner

The circadian rhythm of glucocorticoids has long been recognised within the last 75 years. Since the beginning, researchers have sought to identify basic mechanisms underlying the origin and emergence of the corticosteroid circadian rhythmicity among mammals. Accordingly, Young, Hall and Rosbash, laureates of the 2017 Nobel Prize in Physiology or Medicine, as well as Takahashi’s group among others, have characterised the molecular cogwheels of the circadian system, describing interlocking transcription/translation feedback loops essential for normal circadian rhythms. Plasma glucocorticoid circadian variation depends on the expression of intrinsic clock genes within the anatomic components of the hypothalamic–pituitary–adrenal axis, which are organised in a hierarchical manner. This review presents a general overview of the glucocorticoid circadian clock mechanisms, highlighting the ontogeny of the pituitary–adrenal axis diurnal rhythmicity as well as the involvement of circadian rhythm abnormalities in the physiopathology and diagnosis of Cushing’s disease.

scholarly journals Abnormal glucose tolerance in children with cystic fibrosis: the predictive role of continuous glucose monitoring system

2010 ◽  
Vol 162 (4) ◽  
pp. 705-710 ◽  
Author(s):  
Riccardo Schiaffini ◽  
Claudia Brufani ◽  
Beatrice Russo ◽  
Danilo Fintini ◽  
Antonella Migliaccio ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Glucose Metabolism ◽  
Glucose Tolerance ◽  
Monitoring System ◽  
Continuous Glucose Monitoring ◽  
Glucose Monitoring ◽  
Continuous Glucose Monitoring System ◽  
Abnormal Glucose Tolerance ◽  
Altered Glucose

A long pre-diabetic phase of abnormal glucose tolerance is described in subjects with cystic fibrosis (CF) since childhood.ObjectiveThe aims of the study were to compare oral glucose tolerance test (OGTT) and continuous glucose monitoring system (CGMS) in the diagnosis of altered glucose metabolism, and to longitudinally evaluate the role of CGMS in predicting glucose metabolism deterioration in children with CF.MethodsSeventeen children with CF and 14 controls were enrolled (mean age 13.3±3.0 years). All subjects underwent OGTT and CGMS registration. On the basis of OGTT, children were classified as normal glucose tolerance, impaired glucose tolerance (IGT), IGT plus at least one glucose value above 200 mg/dl at intermediate OGTT points (IGT+200) and CF-related diabetes (CFRD). HbA1c, glucose area under the curve, insulin sensitivity, and insulinogenic and disposition indexes were also considered. Subjects with CF underwent another OGTT after 2.5 years.ResultsBaseline OGTT revealed 3/17 (7.6%) children with CF with at least one glucose value above 200 mg/dl (1 CFRD and 2 IGT+200), while CGMS revealed 6/17 (35.3%) children with glucose excursions above 200 mg/dl (P=0.010). None of the controls showed glucose over 200 mg/dl either at OGTT or at CGMS. At the 2.5-year follow-up OGTT, all the six subjects who had diabetic glucose excursion (i.e. >200 mg/dl) at baseline CGMS presented IGT+200 or CFRD. In logistic regression analysis, CGMS diabetic excursion was the strongest predictor of IGT+200 and CFRD (P<0.001).ConclusionsCGMS could be a useful tool to predict glucose metabolism derangements in children affected by CF.

Abstract 084: Significant Roles of Hyperglycemia and Obesity in the Disruption of Blood Pressure Circadian Rhythm in Leptin-receptor Mutant Db/db Mice

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Tianfei Hou ◽  
Wen Su ◽  
Ming Gong ◽  
Zhenheng Guo
Keyword(s):  
Blood Pressure ◽  
Circadian Rhythm ◽  
Clock Gene ◽  
Leptin Receptor ◽  
Clock Genes ◽  
The Body ◽  
Diabetic Patients ◽  
Receptor Mutant ◽  
Type 2 Diabetic

Blood pressure (BP) exhibits 24-hour rhythm. Loss of BP oscillation has been found in up to 75% diabetic patients and is associated with increased risks of target organ injuries. However, the mechanisms underlying the disruption of BP circadian rhythm in diabetes remain poorly understood. We and others have demonstrated that type 2 diabetic db/db mice in C57/KsJ background have hypertension and severely disrupted BP circadian rhythm. Since these db/db mice were severely hyperglycemic (>600 mg/dL) as well as obese, it is unclear which factor or both contribute to the disruption of BP oscillation. Moreover, it is unclear whether clock genes are involved in the diabetes associated disruption of BP circadian rhythm. To address these specific questions, we cross bred the leptin receptor mutated db/db mice in the C57BL/KsJ background with PERIOD2::LUCIFERASE knock in mice in C57BL/6J background. At 4-5 months old, the blood glucose in these db/db -Per2 mice was higher than controls (320.3 vs 153 mg/dL) but was significantly lower than the C57/KsJ - db/db mice (608.5 mg/dL). However, the body weight of these db/db -per2 mice was significantly higher than both the C57/KsJ- db/db (66.4 vs 44.8 g) as well as control mice (33.9 g). The metabolic flexibility, which is represented by respiratory exchange ratio and measured using TSE LabMaster Indirect Calorimetry System, was significantly compromised in the db/db -per2 mice when compared to controls. We then determined the BP in the db/db -per2 mice using radiotelemetry under 12: 12 light: dark cycle. The circadian parameters of BP, including period length, amplitude and acrophase were calculated using Chronos-fit software. The results demonstrated that db/db -per2 mice have normal BP value but disrupted BP circadian rhythm, with decreased power of 24h oscillation, diminished amplitude and shifted acrophase. However, the extent of the disruption was significantly less than that we have reported in the C57/KsJ- db/db mice. By using LumiCycle, we are currently investigating the clock gene functions in various tissues including SCN, aorta, liver, and etc isolated from db/db -Per2 mice. In summary, we demonstrated that both hyperglycemia and obesity significantly contribute to the disruption in BP circadian rhythm in db/db mice.

scholarly journals TNF signaling impacts glucagon-like peptide-1 expression and secretion

2018 ◽  
Vol 61 (4) ◽  
pp. 153-161 ◽  
Author(s):  
Sufang Chen ◽  
Wei Wei ◽  
Minjie Chen ◽  
Xiaobo Qin ◽  
Lianglin Qiu ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Glucose Metabolism ◽  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Deficient Mice

Numerous studies have implicated tumor necrosis factor α (TNFα) in the pathogenesis of type 2 diabetes. However, the role of its primary receptor, TNF receptor 1 (TNFR1), in homeostatic regulation of glucose metabolism is still controversial. In addition to TNFα, lymphotoxin α (LTα) binds to and activates TNFR1. Thus, TNFα and LTα together are known as TNF. To delineate the role of TNF signaling in glucose homeostasis, the present study ascertained how TNF signaling deficiency affects major regulatory components of glucose homeostasis. To this end, normal diet-fed male TNFR1-deficient mice (TNFR1−/−), TNFα/LTα/LTβ triple-deficient mice (TNF/LT∆3) and their littermate controls were subjected to intraperitoneal glucose tolerance test, insulin tolerance test and oral glucose tolerance test. The present results showed that TNFR1−/− and TNF/LT∆3 mice vs their controls had comparable body weight, tolerance to intraperitoneal glucose and sensitivity to insulin. However, their tolerance to oral glucose was significantly increased. Additionally, glucose-induced insulin secretion assessments revealed that TNFR1 or TNF/LT deficiency significantly increased oral but not intraperitoneal glucose-induced insulin secretion. Consistently, qPCR and immunohistochemistry analyses showed that TNFR1−/− and TNF/LT∆3 mice vs their controls had significantly increased ileal expression of glucagon-like peptide-1 (GLP-1), one of the primary incretins. Their oral glucose-induced secretion of GLP-1 was also significantly increased. These data collectively suggest that physiological TNF signaling regulates glucose metabolism primarily through effects on GLP-1 expression and secretion and subsequently insulin secretion.

scholarly journals Diurnal Amplitudes of Arterial Pressure and Heart Rate Are Dampened in Clock Mutant Mice and Adrenalectomized Mice

Endocrinology ◽  
2008 ◽  
Vol 149 (7) ◽  
pp. 3576-3580 ◽  
Author(s):  
Hiroyoshi Sei ◽  
Katsutaka Oishi ◽  
Sachiko Chikahisa ◽  
Kazuyoshi Kitaoka ◽  
Eiji Takeda ◽  
...  
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Clock Gene ◽  
Clock Genes ◽  
Plasma Aldosterone ◽  
Mutant Mice ◽  
Wild Type ◽  
Clock Mutant ◽  
Wild Type Control

Arterial pressure (AP), heart rate (HR), and cardiovascular diseases, including ischemic heart attack and cerebrovascular accident, show diurnal variation. Evidence that circadian-related genes contribute to cardiovascular control has been accumulated. In this study, we measured the AP and HR of Clock mutant mice on the Jcl/ICR background to determine the role of the Clock gene in cardiovascular function. Mice with mutated Clock genes had a dampened diurnal rhythm of AP and HR, compared with wild-type control mice, and this difference disappeared after adrenalectomy. The diurnal acrophase in both mean arterial pressure and HR was delayed significantly in Clock mutant mice, compared with wild-type mice, and this difference remained after adrenalectomy. Clock mutant mice had a lower concentration of plasma aldosterone, compared with wild-type mice. Our data suggest that the adrenal gland is involved in the diurnal amplitude, but not the acrophase, of AP and HR, and that the function of the Clock gene may be related to the nondipping type of AP elevation.

scholarly journals Rev-erb-α: an integrator of circadian rhythms and metabolism

2009 ◽  
Vol 107 (6) ◽  
pp. 1972-1980 ◽  
Author(s):  
Hélène Duez ◽  
Bart Staels
Keyword(s):  
Circadian Rhythms ◽  
Regulatory Networks ◽  
Animal Studies ◽  
Clock Genes ◽  
Metabolic Response ◽  
Large Body ◽  
Internal Clock ◽  
Glucose And Lipid Metabolism ◽  
Physiological Processes ◽  
Clock Component

The endogenous circadian clock ensures daily rhythms in diverse behavioral and physiological processes, including locomotor activity and sleep/wake cycles, but also food intake patterns. Circadian rhythms are generated by an internal clock system, which synchronizes these daily variations to the day/night alternance. In addition, circadian oscillations may be reset by the time of food availability in peripheral metabolic organs. Circadian rhythms are seen in many metabolic pathways (glucose and lipid metabolism, etc.) and endocrine secretions (insulin, etc.). As a consequence, misalignment of the internal timing system vs. environmental zeitgebers (light, for instance), as experienced during jetlag or shift work, may result in disruption of physiological cycles of fuel utilization or energy storage. A large body of evidence from both human and animal studies now points to a relationship between circadian disorders and altered metabolic response, suggesting that circadian and metabolic regulatory networks are tightly connected. After a review of the current understanding of the molecular circadian core clock, we will discuss the hypothesis that clock genes themselves link the core molecular clock and metabolic regulatory networks. We propose that the nuclear receptor and core clock component Rev-erb-α behaves as a gatekeeper to timely coordinate the circadian metabolic response.

scholarly journals Deletion of the Clock Gene Period2 (Per2) in Glial Cells Alters Mood-Related Behavior in Mice

2020 ◽  
Author(s):  
Tomaz Martini ◽  
Jürgen A. Ripperger ◽  
Jimmy Stalin ◽  
Andrej Kores ◽  
Michael Stumpe ◽  
...  
Keyword(s):  
Glial Cells ◽  
Clock Gene ◽  
Clock Genes ◽  
Specific Expression ◽  
Adeno Associated Virus ◽  
Resistant Phenotype ◽  
Cell Type Specific Expression ◽  
Cell Type Specific ◽  
Physiological Pathways

AbstractThe circadian clock regulates many biochemical and physiological pathways, and lack of clock genes, such as Period (Per) 2, do not only affect circadian activity rhythms, but can also modulate food-anticipatory and mood-related behaviors. However, it is not known how cell-type specific expression of Per2 contributes to these behaviors. In this study, we find that Per2 in glial cells is important for balancing mood-related behaviors. Genetic and adeno-associated virus-mediated deletion of Per2 in glial cells of mice leads to a depression-resistant phenotype, as manifested in reduced despair and anxiety. This is paralleled by an increase of the GABA transporter 3 (Gat3) mRNA and a reduction of glutamate levels in the nucleus accumbens (NAc). Exclusive deletion of Per2 in glia of the NAc reduced despair, but had no influence on anxiety. Our data provide strong evidence for an important role of glial Per2 in regulating mood-related behavior.

scholarly journals BMAL1 but not CLOCK is associated with monochromatic green light-induced circadian rhythm of melatonin in chick pinealocytes

2019 ◽  
Vol 8 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Shuhui Ma ◽  
Zixu Wang ◽  
Jing Cao ◽  
Yulan Dong ◽  
Yaoxing Chen
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Pineal Gland ◽  
Clock Genes ◽  
Critical Role ◽  
Green Light ◽  
Circadian Oscillator ◽  
Melatonin Secretion ◽  
Expression Levels

The avian pineal gland, an independent circadian oscillator, receives external photic cues and translates them for the rhythmical synthesis of melatonin. Our previous study found that monochromatic green light could increase the secretion of melatonin and expression of CLOCK and BMAL1 in chick pinealocytes. This study further investigated the role of BMAL1 and CLOCK in monochromatic green light-induced melatonin secretion in chick pinealocytes using siRNAs interference and overexpression techniques. The results showed that si-BMAL1 destroyed the circadian rhythms of AANAT and melatonin, along with the disruption of the expression of all the seven clock genes, except CRY1. Furthermore, overexpression of BMAL1 also disturbed the circadian rhythms of AANAT and melatonin, in addition to causing arrhythmic expression of BMAL1 and CRY1/2, but had no effect on the circadian rhythms of CLOCK, BMAL2 and PER2/3. The knockdown or overexpression of CLOCK had no impact on the circadian rhythms of AANAT, melatonin, BMAL1 and PER2, but it significantly deregulated the circadian rhythms of CLOCK, BMAL2, CRY1/2 and PER3. These results suggested that BMAL1 rather than CLOCK plays a critical role in the regulation of monochromatic green light-induced melatonin rhythm synthesis in chicken pinealocytes. Moreover, both knockdown and overexpression of BMAL1 could change the expression levels of CRY2, it indicated CRY2 may be involved in the BMAL1 pathway by modulating the circadian rhythms of AANAT and melatonin.

scholarly journals Gentiopicroside Ameliorates Glucose and Lipid Metabolism in T2DM by Activating PI3K/AKT Pathway Via FGFR1

2021 ◽  
Author(s):  
Zhanchi Xu ◽  
Zeyuan Lin ◽  
Jingran Zeng ◽  
Rui Chen ◽  
Chuting Li ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Glucose Metabolism ◽  
Hepg2 Cells ◽  
Growth Factor Receptor ◽  
Akt Pathway ◽  
Phosphatidylinositol 3 Kinase ◽  
Glucose And Lipid Metabolism ◽  
Lipid Metabolism Disorders

Abstract Background: Abnormalities in lipid and glucose metabolism are are constantly occured in type 2 diabetes (T2DM). However, it can be ameliorated by gentiopicroside (GPS). Considering the key role of fibroblast growth factor receptor 1/phosphatidylinositol 3-kinase/protein kinase B (FGFR1/PI3K/AKT) pathway in T2DM, we explore the possible mechanism of GPS on lipid and glucose metabolism through its effects on FGFR1/PI3K/AKT pathway.Methods: Palmitic acid (PA)-induced HepG2 cells and a db/db mice were used to clarify the role and mechanism of polydatin on lipid and glucose metabolism.Results: GPS ameliorated glucose and lipid metabolism disorders in db/db mice and PA-induced HepG2 cells. Furthermore, GPS activated FGFR1/PI3K/AKT pathway including increased the protein expression of FGFR1 and promoted the phosphorylation of PI3K, AKT and FoxO1. Additionally, knockdown of FGFR1 reversed the activation of PI3K/AKT pathway by GPS.Conclusions: The present study demontrates that GPS ameliorates glucose and lipid metabolism disorders via activation of FGFR1/PI3K/AKT pathway.

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