scholarly journals Hypoxia Inhibits Cavin-1 and Cavin-2 Expression and Down-Regulates Caveolae in Adipocytes

Endocrinology ◽  
2015 ◽  
Vol 156 (3) ◽  
pp. 789-801 ◽  
Author(s):  
Claire Regazzetti ◽  
Karine Dumas ◽  
Sandra Lacas-Gervais ◽  
Faustine Pastor ◽  
Pascal Peraldi ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Signaling ◽  
Hypoxia Inducible Factor ◽  
Insulin Receptors ◽  
Underlying Mechanism ◽  
Epididymal Adipose Tissue ◽  
Diabetic Patients ◽  
Model Assessment ◽  
Hypoxia Inducible Factor 1

Abstract During obesity, a hypoxic state develops within the adipose tissue, resulting in insulin resistance. To understand the underlying mechanism, we analyzed the involvement of caveolae because they play a crucial role in the activation of insulin receptors. In the present study, we demonstrate that in 3T3-L1 adipocytes, hypoxia induces the disappearance of caveolae and inhibits the expression of Cavin-1 and Cavin-2, two proteins necessary for the formation of caveolae. In mice, hypoxia induced by the ligature of the spermatic artery results in the decrease of cavin-1 and cavin-2 expression in the epididymal adipose tissue. Down-regulation of the expression of cavins in response to hypoxia is dependent on hypoxia-inducible factor-1. Indeed, the inhibition of hypoxia-inducible factor-1 restores the expression of cavins and caveolae formation. Expression of cavins regulates insulin signaling because the silencing of cavin-1 and cavin-2 impairs insulin signaling pathway. In human, cavin-1 and cavin-2 are decreased in the sc adipose tissue of obese diabetic patients compared with lean subjects. Moreover, the expression of cavin-2 correlates negatively with the homeostatic model assessment index of insulin resistance and glycated hemoglobin level. In conclusion, we propose a new mechanism in which hypoxia inhibits cavin-1 and cavin-2 expression, resulting in the disappearance of caveolae. This leads to the inhibition of insulin signaling and the establishment of insulin resistance.

scholarly journals Obesity: The role of desynchronosis and genetic factors in mechanisms of its development

2017 ◽  
Vol 8 (1) ◽  
pp. 23-29
Author(s):  
M. O. Ryznychuk ◽  
V. P. Pishak
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Signaling ◽  
Genetic Factors ◽  
Hormone Secretion ◽  
Insulin Receptors ◽  
Secretory Activity ◽  
Membrane Receptors ◽  
Brown Adipose

The article highlights the role of desynchronosis and certain genetic factors in the development of obesity. Some pathogenetic links of obesity and the influence of melatonin on them are analyzed.Desynchronosis is one of the causes of obesity as a result of dysregulatory changes in the chronoperiodic system – between suprachiasmatic nuclei of the hypothalamus and secretory activity of the pineal gland.In obesity there are some changes in circadian patterns of important physiological parameters. These include acrophases of blood pressure; rhythm of hormone secretion, including insulin; electrolytes; sleep-wake cycle displaced for a period of a day, which is a deviation from the normal course. Phase discrepancies of established circadian oscillations of physiological processes arise. Preconditions of fat metabolism imbalance, particularly visfatin, apelin and vaspin – components of atherosclerotic lesions, gradually emerge.There is abundant evidence for close relationships between metabolism and circadian mechanisms. It is proved, that there is a strong direct impact of endogenous circadian rhythms on the metabolic pathways that do not depend on food intake or sleep. A potential low molecular weight of biomarkers of human circadian phases has been identified. A number of key metabolic enzymes in tissues such as the liver, adipose tissue or the pancreas are chronodependent. Desynchronosis phenomena caused by genetic or environmental factors can lead to serious metabolic disorders, including obesity, insulin resistance and metabolic syndrome.Genesis of pineal removal-induced insulin resistance and reduced glucose tolerance in cells is related to the consequences of melatonin absence, which leads to abnormalities in insulin signaling pathways and reduced GLUT4 gene expression and protein content.Insulin-sensitive tissues (white and brown adipose tissue, skeletal and heart muscles) after pineal removal are characterized by a significant reduction of GLUT4 mRNA and the content of microsomal and membrane proteins, which are compensated during treatment by melatonin. Functional synergy exists between melatonin and insulin. Melatonin is able through the membrane receptors MT1 to cause rapid tyrosine phosphorylation, activate tyrosine kinase of beta subunits of insulin receptors and mobilize several intracellular stages of insulin-signaling pathway transduction.Thus, the protective effect of melatonin in cases of disturbance to the carbohydrate metabolism is manifested in the formation of circadian periodicity by modulating the expression of time genes.

scholarly journals Maternal Protein Restriction Altered Insulin Resistance and Inflammation-Associated Gene Expression in Adipose Tissue of Young Adult Mouse Offspring in Response to a High-Fat Diet

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1103 ◽  
Author(s):  
Juhae Kim ◽  
Alee Choi ◽  
Young Hye Kwon
Keyword(s):  
Gene Expression ◽  
Insulin Resistance ◽  
Adipose Tissue ◽  
Serum Insulin ◽  
Protein Restriction ◽  
Epididymal Adipose Tissue ◽  
Model Assessment ◽  
High Fat ◽  
Maternal Protein Restriction ◽  
Increased Risk

Maternal protein restriction is associated with increased risk of insulin resistance and inflammation in adulthood offspring. Here, we investigated whether maternal protein restriction could alter the risk of metabolic syndrome in postweaning high-fat (HF)-diet-challenged offspring, with focus on epididymal adipose tissue gene expression profile. Female ICR mice were fed a control (C) or a low-protein (LP) diet for two weeks before mating and throughout gestation and lactation, and their male offspring were fed an HF diet for 22 weeks (C/HF and LP/HF groups). A subset of offspring of control dams was fed a low-fat control diet (C/C group). In response to postweaning HF diet, serum insulin level and the homeostasis model assessment of insulin resistance (HOMA-IR) were increased in control offspring. Maternal LP diet decreased HOMA-IR and adipose tissue inflammation, and increased serum adiponectin level in the HF-diet-challenged offspring. Accordingly, functional analysis revealed that differentially expressed genes (DEGs) enriched in cytokine production were downregulated in the LP/HF group compared to the C/HF group. We also observed the several annotated gene ontology terms associated with innate immunity and phagocytosis in down-regulated DEGs between LP/HF and C/C groups. In conclusion, maternal protein restriction alleviated insulin resistance and inflammation in young offspring mice fed a HF diet but may impair development of immune system in offspring.

scholarly journals SAT0111 THE RELATIONSHIP BETWEEN THE ADMINISTRATION OF IL-6 INHIBITORS AND INSULIN RESISTANCE IN PATIENTS WITH ACTIVE RHEUMATOID ARTHRITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 989.3-989
Author(s):  
A. Jitaru ◽  
C. Pomirleanu ◽  
M. M. Leon-Constantin ◽  
F. Mitu ◽  
C. Ancuta
Keyword(s):  
Rheumatoid Arthritis ◽  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Beneficial Effect ◽  
Disease Activity ◽  
Interleukin 6 ◽  
Normal Weight ◽  
Diabetic Patients ◽  
Model Assessment ◽  
Inflammatory Status

Background:Rheumatoid arthritis (RA) is associated with an increased cardiovascular (CV) risk, due not only to the traditional risk factors (hypertension, insulin resistance/diabetes, obesity, smoking), but to the inflammatory status as well. The blockade of interleukin-6 (IL-6) can regulate the glucose metabolism, reducing the glucose level and insulin resistance (IR). This beneficial effect is seen more in patients with normal values of body mass index (BMI), compared to the obese population.Objectives:Given the mentioned existing data, we aim to demonstrate the positive effect of IL-6 inhibitors in active RA patients with normal or increased BMI.Methods:We recruited 56 consecutive patients with definite and active RA, non-responders/partial responders to conventional synthetic Drug Modifying Anti-Rheumatic Drugs (csDMARDs)/biological therapy. For a period of 52 weeks, patients received subcutaneous Tocilizumab (TCZ) in a dose of 162mg once a week, according to European League Anti Rheumatism (EULAR) recommendation and National Protocol. We assessed demographics, RA-related parameters (clinical, inflammatory and immune) and metabolic markers, as well as the peripheral response to insulin, quantified by Homeostasis Model Assessment for insulin resistance (HOMA-IR) and the Quantitative Insulin Sensitivity Check Index (QUICKI). We did not include in the study the patients known with diabetes mellitus (DM) and those undergoing glucocorticoids.Results:After 52 weeks of treatment, most of the patients showed a statistically significant reduction of HOMA-IR (3.61 ± 1.21 at the onset vs. 2.45 ± 1.46 at the end of the study, p<0.001), while QUICKI registered a slight increase (0.32 ± 0.01 at the onset vs. 0.33 ± 0.01 at the end of the study, p<0.001). Also, the decrease in insulin and glucose levels were more obvious in patients with normal BMI, strictly related to disease activity.Conclusion:Long-term administration of TCZ in active RA is associated with a significant reduction of disease activity and IR, especially in normal weight patients. This confirms that obesity, as a CV risk factor, represents one of the main causes of IR.References:[1]Castañeda S, Remuzgo-Martínez S, López-Mejías R et al. Rapid beneficial effect of the IL-6 receptor blockade on insulin resistance and insulin sensitivity in non-diabetic patients with rheumatoid arthritis.Clin Exp Rheumatol. 2019; 37(3):465-473.[2]Lehrskov LL, Christensen RH. The role of interleukin-6 in glucose homeostasis and lipid metabolism.Semin Immunopathol. 2019; 41(4):491-499.[3]Ursini F, Russo E, Ruscitti P, Giacomelli R, De Sarro G. The effect of non-TNF-targeted biologics and small molecules on insulin resistance in inflammatory arthritis.Autoimmun Rev. 2018 Apr;17(4):399-404.Disclosure of Interests:Alexandra Jitaru: None declared, Cristina Pomirleanu: None declared, Maria-Magdalena Leon-Constantin: None declared, Florin Mitu: None declared, CODRINA ANCUTA Consultant of: AbbVie, Pfizer, Roche, Novartis, UCB, Ewopharma, Merck Sharpe and Dohme, and Eli Lilly, Speakers bureau: AbbVie, Pfizer, Roche, Novartis, UCB, Ewopharma, Merck Sharpe and Dohme, and Eli Lilly

Investigating the relationship between insulin resistance and adipose tissue in a randomized Tehrani population

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jalaledin Mirzay Razzaz ◽  
Hossein Moameri ◽  
Zahra Akbarzadeh ◽  
Mohammad Ariya ◽  
Seyed ali Hosseini ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Body Fat ◽  
Odds Ratio ◽  
Cross Sectional Study ◽  
Model Assessment ◽  
Fasting Insulin ◽  
Cross Sectional ◽  
Body Fat Percent ◽  
The Relationship

Abstract Objectives Insulin resistance is the most common metabolic change associated with obesity. The present study aimed to investigate the relationship between insulin resistance and body composition especially adipose tissue in a randomized Tehrani population. Methods This study used data of 2,160 individuals registered in a cross-sectional study on were randomly selected from among subjects who were referred to nutrition counseling clinic in Tehran, from April 2016 to September 2017. Insulin resistance was calculated by homeostasis model assessment formula. The odds ratio (95% CI) was calculated using logistic regression models. Results The mean age of the men was 39 (±10) and women were 41 (±11) (the age ranged from 20 to 50 years). The risk of increased HOMA-IR was 1.03 (95% CI: 1.01–1.04) for an increase in one percent of Body fat, and 1.03 (95% CI: 1.00–1.05) for an increase in one percent of Trunk fat. Moreover, the odds ratio of FBS for an increase in one unit of Body fat percent and Trunk fat percent increased by 1.05 (adjusted odds ratio [95% CI: 1.03, 1.06]) and 1.05 (95% CI: 1.02, 1.08). Also, the risk of increased Fasting Insulin was 1.05 (95% CI: 1.03–1.07) for an increase in one unit of Body fat percent, and 1.05 (95% CI: 1.02–1.08) for an increase in one unit of Trunk fat percent. Conclusions The findings of the present study showed that there was a significant relationship between HOMA-IR, Fasting blood sugar, Fasting Insulin, and 2 h Insulin with percent of Body fat, percent of Trunk fat.

scholarly journals Plasma resistin, adiponectin and leptin levels in lean and obese subjects: correlations with insulin resistance

2003 ◽  
Vol 149 (4) ◽  
pp. 331-335 ◽  
Author(s):  
JV Silha ◽  
M Krsek ◽  
JV Skrha ◽  
P Sucharda ◽  
BL Nyomba ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Mass Index ◽  
Adipose Tissue ◽  
Statistical Significance ◽  
Model Assessment ◽  
Fasting Insulin ◽  
Homeostasis Model Assessment ◽  
Glucose Levels ◽  
Obese Subjects ◽  
The Relationship

OBJECTIVE: Adipose tIssue regulates insulin sensitivity via the circulating adipocytokines, leptin, resistin and adiponectin. The objective of this study was to compare the levels of resistin, adiponectin and leptin in lean and obese subjects and determine the relationship between circulating adipocytokines and insulin resistance. METHODS: We examined plasma levels of resistin, adiponectin and leptin in 17 lean subjects with a mean body mass index (BMI) of approximately 23 and 34 non-diabetic obese individuals with a mean BMI approximately 33. Insulin resistance was assessed using the homeostasis model assessment ratio (HOMA-R) formula derived from fasting insulin and glucose levels. RESULTS: Resistin levels were not significantly different between the two groups but were significantly higher in women compared with men, 35.4+/-6.5 (s.e.) vs 15.4+/-2.9 microg/L, P<0.01. Resistin did not correlate with BMI but did significantly correlate with HOMA-R, P<0.01, and this correlation remained significant after adjustment for gender and BMI. Adiponectin levels were significantly lower in obese compared with lean subjects, P<0.005, and higher in women, P<0.001, but showed no significant correlation with HOMA-R. Leptin levels were significantly higher in obese subjects and women and correlated with HOMA-R and resistin. DISCUSSION: In this small group of patients we demonstrated that insulin resistance correlated most strongly with leptin levels. A significant correlation between resistin levels and insulin resistance was also observed. Although a similar trend was apparent for adiponectin, the correlation with insulin resistance did not achieve statistical significance.

scholarly journals Insulin Resistance as a Predictor of Cardiovascular Disease in Patients on peritoneal dialysis

2013 ◽  
Vol 33 (4) ◽  
pp. 411-418 ◽  
Author(s):  
Yun Li ◽  
Lihua Zhang ◽  
Yong Gu ◽  
Chuanming Hao ◽  
Tongying Zhu
Keyword(s):  
Insulin Resistance ◽  
Peritoneal Dialysis ◽  
Independent Predictor ◽  
Hazard Ratio ◽  
Diabetic Patients ◽  
Model Assessment ◽  
Mortality Hazard ◽  
Cv Disease ◽  
The Impact ◽  
Mortality Hazard Ratio

BackgroundInsulin resistance is associated with multiple risk factors for cardiovascular (CV) disease in the general population. Patients on peritoneal dialysis (PD) are more likely to develop insulin resistance. However, no evaluation of the impact of insulin resistance on CV disease morbidity or mortality in patients on PD has been performed.MethodsOur prospective cohort study included all non-diabetic patients on PD at our center ( n = 66). Insulin resistance was evaluated at baseline by the homeostasis model assessment method (HOMA-IR) using fasting glucose and insulin levels. The cohort was followed for up to 58 months (median: 41.3 months; interquartile range: 34.3 months). A multivariate Cox model was used to analyze the impact of insulin resistance on CV disease mortality.ResultsFourteen CV events occurred in the higher HOMA-IR group [IR-H (HOMA-IR values in the range 2.85 – 19.5), n = 33], but only one event occurred in the lower HOMA-IR group (IR-L (HOMA-IR values in the range 0.83 – 2.71), n = 33) during the follow-up period. Level of HOMA-IR was a significant predictor of CV events [risk ratio: 17.7; 95% confidence interval (CI): 2.10 to 149.5; p = 0.008]. In the IR-H group, 10 patients died (8 CV events), but in the IR-L group, only 4 patients died (1 CV event). Patients in the IR-H group experienced significantly higher CV mortality (hazard ratio: 9.02; 95% CI: 1.13 to 72.2; p = 0.04). Even after adjustments for age, systolic blood pressure, body mass index, C-reactive protein, triglycerides, resistin, and leptin, HOMA-IR remained an independent predictor of CV mortality (hazard ratio: 14.8; 95% CI: 1.22 to 179.1; p = 0.03).ConclusionsInsulin resistance assessed using HOMA-IR was an independent predictor of CV morbidity and mortality in a cohort of nondiabetic patients on PD. Insulin resistance is a modifiable risk factor; the reduction of insulin resistance may reduce CV risk and improve survival in this group of patients.

scholarly journals Endothelial insulin receptors differentially control insulin signaling kinetics in peripheral tissues and brain of mice

2017 ◽  
Vol 114 (40) ◽  
pp. E8478-E8487 ◽  
Author(s):  
Masahiro Konishi ◽  
Masaji Sakaguchi ◽  
Samuel M. Lockhart ◽  
Weikang Cai ◽  
Mengyao Ella Li ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Endothelial Cells ◽  
Food Intake ◽  
Insulin Signaling ◽  
Insulin Action ◽  
Insulin Receptors ◽  
Brain Regions ◽  
Peripheral Tissues ◽  
Systemic Insulin Resistance

Insulin receptors (IRs) on endothelial cells may have a role in the regulation of transport of circulating insulin to its target tissues; however, how this impacts on insulin action in vivo is unclear. Using mice with endothelial-specific inactivation of the IR gene (EndoIRKO), we find that in response to systemic insulin stimulation, loss of endothelial IRs caused delayed onset of insulin signaling in skeletal muscle, brown fat, hypothalamus, hippocampus, and prefrontal cortex but not in liver or olfactory bulb. At the level of the brain, the delay of insulin signaling was associated with decreased levels of hypothalamic proopiomelanocortin, leading to increased food intake and obesity accompanied with hyperinsulinemia and hyperleptinemia. The loss of endothelial IRs also resulted in a delay in the acute hypoglycemic effect of systemic insulin administration and impaired glucose tolerance. In high-fat diet-treated mice, knockout of the endothelial IRs accelerated development of systemic insulin resistance but not food intake and obesity. Thus, IRs on endothelial cells have an important role in transendothelial insulin delivery in vivo which differentially regulates the kinetics of insulin signaling and insulin action in peripheral target tissues and different brain regions. Loss of this function predisposes animals to systemic insulin resistance, overeating, and obesity.

scholarly journals Complement Factor C3 Methylation and mRNA Expression Is Associated to BMI and Insulin Resistance in Obesity

Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 410 ◽  
Author(s):  
Daniel Castellano-Castillo ◽  
Isabel Moreno-Indias ◽  
Jose Carlos Fernandez-Garcia ◽  
Mercedes Clemente-Postigo ◽  
Manuel Castro-Cabezas ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Dna Methylation ◽  
Adipose Tissue ◽  
Messenger Rna ◽  
Density Lipoprotein ◽  
Complement Factor ◽  
Mrna Levels ◽  
Model Assessment ◽  
Tissue Samples ◽  
Obese Class

Epigenetic marks, and especially DNA methylation, are becoming an important factor in obesity, which could help to explain its etiology and associated comorbidities. Adipose tissue, now considered as an important endocrine organ, produces complement system factors. Complement component 3 (C3) turns out to be an important protein in metabolic disorders, via either inflammation or the C3 subproduct acylation stimulating protein (ASP) which directly stimulates lipid storage. In this study, we analyze C3 DNA methylation in adipose tissue from subjects with a different grade of obesity. Adipose tissue samples were collected from subjects with a different degree of obesity determined by their body mass index (BMI) as: Overweight subjects (BMI ≥ 25 and <30), obese class 1/2 subjects (BMI ≥ 30 and <40) and obese class 3 subjects (BMI ≥ 40). C3 DNA methylation was measured for 7 CpGs by pyrosequencition using the Pyromark technology (Qiagen, Madrid Spain). C3 messenger RNA (mRNA) levels were analyzed by pre-designed Taqman assays (Applied biosystems, Foster City, CA, USA) and ASP/C3a was measured using a ELISA kit. The data were analyzed using the statistic package SPSS. C3 DNA methylation levels were lower in the morbid obese group. Accordingly, C3 methylation correlated negatively with BMI and leptin. However, C3 mRNA levels were more associated with insulin resistance, and positive correlations with insulin, glucose and homeostasis model assessment-estimated insulin resistance (HOMA-IR) existed. ASP correlated negatively with high density lipoprotein (HDL) cholesterol. C3 methylation levels were associated to adiposity variables, such as BMI and leptin, while the C3 mRNA levels were associated to glucose metabolism.

scholarly journals The Relationship between Epicardial Adipose Tissue Thickness and Serum Interleukin-17a Level in Patients with Isolated Metabolic Syndrome

Biomolecules ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 97 ◽  
Author(s):  
Esra Demir ◽  
Nazmiye Harmankaya ◽  
İrem Kıraç Utku ◽  
Gönül Açıksarı ◽  
Turgut Uygun ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Epicardial Adipose Tissue ◽  
Control Group ◽  
Model Assessment ◽  
Tissue Thickness ◽  
The Metabolic Syndrome ◽  
Epicardial Adipose Tissue Thickness ◽  
The Relationship

In this study, it was aimed to investigate the relationship between the epicardial adipose tissue thickness (EATT) and serum IL-17A level insulin resistance in metabolic syndrome patients. This study enrolled a total of 160 subjects, of whom 80 were consecutive patients who applied to our outpatient clinic and were diagnosed with metabolic syndrome, and the other 80 were consecutive patients who were part of the control group with similar age and demographics in whom the metabolic syndrome was excluded. The metabolic syndrome diagnosis was made according to International Diabetes Federation (IDF)-2005 criteria. EATT was measured with transthoracic echocardiography (TTE) in the subjects. IL-17A serum levels were determined using the ELISA method. Fasting blood glucose, HDL, triglyceride, and fasting insulin levels were significantly higher in the metabolic syndrome group compared to the control group. In addition, the metabolic syndrome group had significantly higher high-sensitivity C-reactive protein (hs-CRP) and Homeostatic Model Assessment Insulin Resistance (HOMA-IR) levels than the control group. Similarly, serum IL-17A levels were significantly elevated in the metabolic syndrome group compared to the control group statistically (p < 0.001). As well, EATT was higher in the metabolic syndrome than the control group. Conclusion: By virtue of their proinflammatory properties, EATT and IL-17 may play an important role in the pathogenesis of the metabolic syndrome.

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