Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Visceral obesity is among the known risk factors of atherosclerotic cardiovascular diseases. As long as adipose tissue was considered only an inert store of excess energy, accumulated in triglycerides, explanation of the mechanisms causing increased cardiovascular risk in obesity was difficult. Finding that the adipose tissue is an active endocrine organ and that the adipokines secreted in it influence several metabolic processes, allowed better understanding of this correlation. Several disturbances in secretion, function and balance of adipokines occur in the course of obesity. Changes of adiponectin, leptin and resistin concentrations are among the reasons of accelerated atherosclerosis occurring in the visceral adiposity. Adiponectin concentrations are decreased in visceral adiposity. Adiponectin is adipokine possessing antiatherogenic properties. It's effects exerted though the specific receptors in skeletal muscles and liver include decreased insulin resistance and improved plasma lipid profile. Acting directly in the vessel wall adiponectin prevents development of atheromatic lesions by inhibiting production of adhesive molecules and formation of foam cells. It has been found that decreased adiponectin concentrations are connected not only with increased coronary risk but also with progression of atherosclerosis in coronary vessels. Moreover it was found that adiponectin plasma concentration is significantly decreased in acute coronary incidences. Leptin regulates energy metabolism and balance. The concentrations of this adipokine are increased in obesity and correlate with insulin resistance. Hiperleptinemia has been also recognized as cardiovascular diseases risk factor. Resistin is considered to be a substance increasing insulin resistance, however the exact mechanisms are not known. Resistin plasma concentrations are increased in obese subjects and correlate with the inflammatory state that underlies the initiation and progression of atherosclerotic lesions. Correlation between resistin concentration and the extent of atherosclerotic plaques in the coronary vessels has also been found. The disturbances in secretion, function and balance of adiponectin, leptin and resistin are to be considered not only a link between visceral adiposity and cardiovascular risk but also independent risk factor of coronary heart disease.
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PMID:[Adipokines: adiponectin, leptin, resistin and coronary heart disease risk]. 1652 24

Resistin is a 12.5-kDa polypeptide hormone produced by adipocytes and immunocompetent cells. It was originally proposed as a link between obesity and insulin resistance/diabetes. Later, studies revealed that substantial inter-species differences exist between the major sites of resistin production in rodents (adipocytes) and humans (immunocompetent cells). While in rodents resistin appears to have an important role in the development of liver insulin resistance, its role in humans is less clear, and it is probably involved in the regulation of inflammatory processes rather than in insulin sensitivity. Current experimental and clinical data concerning resistin physiology and pathophysiology, and its possible role in the development of insulin resistance and atherosclerosis are detailed in this review.
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PMID:The role of resistin in obesity-induced insulin resistance. 1662 16

We studied the effect of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) activation on serum concentrations and tissue expression of resistin, adiponectin, and adiponectin receptor-1 and -2 (AdipoR1 and AdipoR2) mRNA in normal mice and mice with insulin resistance induced by lipogenic, simple-carbohydrate diet (LD). Sixteen weeks of LD feeding induced obesity with liver steatosis and increased insulin levels but did not significantly affect circulating adiponectin or resistin. Treatment with PPAR-alpha agonist fenofibrate decreased body weight and fat pad weight and ameliorated liver steatosis in LD-fed mice with concomitant reduction in blood glucose, free fatty acid, triglyceride, serum insulin levels, and homeostasis model assessment index values. Euglycemic-hyperinsulinemic clamp demonstrated the development of whole-body and liver insulin resistance in LD-fed mice, which were both normalized by fenofibrate. Fenofibrate treatment markedly increased circulating resistin levels on both diets and adiponectin levels in chow-fed mice only. Fat adiponectin mRNA expression was not affected by fenofibrate treatment. Resistin mRNA expression increased in subcutaneous but not gonadal fat after fenofibrate treatment. In addition to fat, a significant amount of adiponectin mRNA was also expressed in the muscle. This expression markedly increased after fenofibrate treatment in chow- but not in LD-fed mice. Adipose tissue expression of AdipoR1 mRNA was significantly reduced in LD-fed mice and increased after fenofibrate treatment. In conclusion, PPAR-alpha activation ameliorated the development of insulin resistance in LD-fed mice despite a major increase in serum resistin levels. This effect could be partially explained by increased AdipoR1 expression in adipose tissue after fenofibrate treatment.
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PMID:Improvement of insulin sensitivity after peroxisome proliferator-activated receptor-alpha agonist treatment is accompanied by paradoxical increase of circulating resistin levels. 1674 Sep 70

Resistin is secreted from adipocytes, and high circulating levels have been associated with obesity and insulin resistance. To investigate whether resistin could exert autocrine effects in adipocytes, we expressed resistin gene in 3T3-L1 fibroblasts using a lentiviral vector, and selected several stably-transduced cell lines under blasticidin selection. We observed that 3T3-L1 adipocytes expressing resistin have a decreased gene expression for related transcriptional factors (CCAAT/enhancer binding protein alpha(C/EBPalpha), peroxisome proliferator-activated receptor gamma (PPARgamma), and adipocyte lipid binding protein (ALBP/aP2) which is one of target genes for the PPARgamma during adipocyte differentiation,. Overexpression of resistin increased the levels of three proinflammatory cytokines, tumor necrosis factor alpha (TNFalpha), interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1), which play important roles for insulin resistance, glucose and lipid metabolisms during adipogenesis. Furthermore, overexpressing resistin in adipocytes inhibits glucose transport 4 (GLUT4) activity and its gene expression, reducing insulin's ability for glucose uptake by 30%. In conclusion, resistin overexpression in stably transduced 3T3-L1 cells resulted in: 1) Attenuation of programmed gene expression responsible for adipogenesis; 2) Increase in expression of proinflammatory cytokines; 3) Decrease in insulin responsiveness of the glucose transport system. These data suggest a new role for resistin as an autocrine/paracrine factor affecting inflammation and insulin sensitivity in adipose tissue.
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PMID:Proinflammatory cytokine production and insulin sensitivity regulated by overexpression of resistin in 3T3-L1 adipocytes. 1685 42

Resistin is an adipokine related to obesity and insulin resistance. Expression of the resistin gene is repressed by the treatment of peroxisome proliferator-activated receptor gamma (PPARgamma) agonists, thiazolidinediones (TZDs). In this study, we investigated the mechanism by which TZDs inhibit the resistin gene expression. Resistin gene expression was decreased by TZD in fully differentiated 3T3-L1 adipocytes, which was abolished after treatment of cycloheximide (a protein synthesis inhibitor). TZD could not repress the expression of the resistin gene in the presence of mithramycin A (an Sp1 binding inhibitor). Sp1 binding site of the resistin promoter (-122/-114bp) was necessary for the repression. Further investigation of the effect of TZDs on the modification of Sp1 showed that the level of O-glycosylation of Sp1 was decreased in this process. These results suggest that PPARgamma activation represses the expression of the resistin gene by modulating Sp1 activity.
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PMID:Sp1 mediates repression of the resistin gene by PPARgamma agonists in 3T3-L1 adipocytes. 1687 20

Elevated plasma levels of fat-derived signaling molecules are associated with obesity, vascular endothelial dysfunction, and coronary heart disease; however, little is known about their direct coronary vascular effects. Accordingly, we examined mechanisms by which one adipokine, resistin, affects coronary vascular tone and endothelial function. Studies were conducted in anesthetized dogs and isolated coronary artery rings. Resistin did not change coronary blood flow, mean arterial pressure, or heart rate. Resistin had no effect on acetylcholine-induced relaxation of artery rings; however, resistin did impair bradykinin-induced relaxation. Selective impairment was also observed in vivo, as resistin attenuated vasodilation to bradykinin but not to acetylcholine. Resistin had no effect on dihydroethidium fluorescence, an indicator of superoxide (O(2)(-)) production, and the inhibitory effect of resistin on bradykinin-induced relaxation persisted in the presence of Tempol, a superoxide dismutase mimetic. To determine whether resistin impaired production of and/or responses to nitric oxide (NO) or prostaglandins (e.g., prostacyclin; PGI(2)), we performed experiments with N(omega)-nitro-L-arginine methyl ester (L-NAME) and indomethacin. The effect of resistin to attenuate bradykinin-induced vasodilation persisted in the presence of L-NAME or indomethacin, suggesting resistin may act at a cell signaling point upstream of NO or PGI(2) production. Resistin-induced endothelial dysfunction is not generalized, and it is not consistent with effects mediated by O(2)(-) or interference with NO or PGI(2) signaling. The site of the resistin-induced impairment is unknown but may be at the bradykinin receptor or a closely associated signal transduction machinery proximal to NO synthase or cyclooxygenase.
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PMID:Resistin impairs endothelium-dependent dilation to bradykinin, but not acetylcholine, in the coronary circulation. 1690 96

The expression of resistin protein in normal human abdominal, thigh, pregnant women abdominal, non-pregnant women abdominal subcutaneous adipose tissue and placenta and the relationship between obesity, type 2 diabetes mellitus (T2DM), pregnant physiological insulin resistance (IR) and gestational diabetes mellitus (GDM) was investigated. The expression of resistin protein in normal human abdominal, thigh, pregnant women abdominal, non-pregnant women abdominal subcutaneous adipose tissue and placenta was detected by using Western blotting method. Fasting serum glucose concentration was measured by glucose oxidase assay. Serum cholesterol (CHOL), serum triglycerides (TG), serum HDL cholesterol (HDL-C) and serum LDL cholesterol (LDL-C) were determined by full automatic biochemical instrument. Fasting insulin was measured by enzyme immunoassay to calculate insulin resistance index (IRI). Height, weight, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured to calculate body mass index (BMI) and body fat percentage (BF %). Resistin protein expression in pregnant women placental tissue (67 905 +/- 8441) (arbitrary A values) was much higher than that in subcutaneous adipose tissue in pregnant women abdomen (40 718 +/- 3818, P < 0.01), non-pregnant women abdomen (38 288 +/- 2084, P < 0.01), normal human abdomen (39 421 +/- 6087, P < 0.01) and thigh (14 942 +/- 6706, P < 0.001) respectively. The resistin expression in abdominal subcutaneous adipose tissue showed no significant difference among pregnant, non-pregnant women and normal human, but much higher than that in thigh subcutaneous adipose tissue (P < 0.001). Pearson analysis revealed that resistin protein was correlated with BMI (r = 0.42), fasting insulin concentration (r = 0.38), IRI (r = 0.34), BF % (r = 0.43) and fasting glucose (r = 0.39), but not with blood pressure, CHOL, TG, HDL-C and LDL-C. It was suggested that resistin protein expression in human abdominal subcutaneous adipose tissue was much higher than that in human thigh subcutaneous adipose tissue. Resistin was closely related with central obesity, leading to IR, subsequently obesity and T2DM. Resistin protein expression in placental tissue was much higher than that in subcutaneous adipose tissue in normal human abdomen, pregnant abdomen, non-pregnant women abdomen and thigh. It was indicated that resistin protein could be secreted from human placental tissue. Resistin might be one of the factors that lead to pregnant physiological IR and GDM.
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PMID:Expression of resistin protein in normal human subcutaneous adipose tissue and pregnant women subcutaneous adipose tissue and placenta. 1696 Dec 71

This study investigated levels of fasting plasma glucose (FBS), homeostasis model of the assessment of the insulin resistance (HOMA), lipid profile, insulin, and resistin hormones in 202 individuals, divided into four groups. Two groups had type II diabetes mellitus (DM): one group had been overnourished (DM/OB) (body mass index: BMI equal or above 25) and the other had not (DM/nOB). Two additional groups not suffering from diabetes were either overnourished (nDM/OB) or of normal nutritional status (nDM/nOB). Only the DM/OB group had insulin levels elevated above the other three groups. Resistin levels had been lowest in the nDM/nOB group. When participants of the two nOB groups were pooled into one group and the subjects of the two OB groups were combined into another group, the median plasma resistin levels of the OB groups were significantly higher compared with the nOB groups. Likewise the DM groups had higher resistin levels than the nDM groups. A significant correlation of plasma resistin with BMI, waist circumference, waist-to-hip ratio, FBS, and HOMA score had been observed. The result suggests that plasma resistin has a role in linking central obesity and obesity-related insulin resistance to type II diabetes mellitus.
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PMID:Plasma resistin, insulin concentration in non-diabetic and diabetic, overweight/obese Thai. 1704 91

Resistin levels are increased in obesity, and hyperresistinemia impairs glucose homeostasis in rodents. Here, we have determined the role of resistin in ob/ob mice that are obese and insulin resistant because of genetic deficiency of leptin. Loss of resistin increased obesity in ob/ob mice by further lowering the metabolic rate without affecting food intake. Nevertheless, resistin deficiency improved glucose tolerance and insulin sensitivity in these severely obese mice, largely by enhancing insulin-mediated glucose disposal in muscle and adipose tissue. In contrast, in C57BL/6J mice with diet-induced obesity but wild-type leptin alleles, resistin deficiency reduced hepatic glucose production and increased peripheral glucose uptake. Resistin deficiency enhanced Akt phosphorylation in muscle and liver and decreased suppressor of cytokine signaling-3 level in muscle, and these changes were reversed by resistin replacement. Together, these results provide strong support for an important role of resistin in insulin resistance and diabetes associated with genetic or diet-induced obesity.
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PMID:Loss of resistin improves glucose homeostasis in leptin deficiency. 1706 46

Obesity and insulin resistance accelerate the progression of fibrosis during chronic liver disease. Resistin antagonizes insulin action in rodents, but its role in humans is still controversial. The aims of this study were to investigate resistin expression in human liver and to evaluate whether resistin may affect the biology of activated human hepatic stellate cells (HSCs), key modulators of hepatic fibrogenesis. Resistin gene expression was low in normal human liver but was increased in conditions of severe fibrosis. Up-regulation of resistin during chronic liver damage was confirmed by immunohistochemistry. In a group of patients with alcoholic hepatitis, resistin expression correlated with inflammation and fibrosis, suggesting a possible action on HSCs. Exposure of cultured HSCs to recombinant resistin resulted in increased expression of the proinflammatory chemokines monocyte chemoattractant protein-1 and interleukin-8, through activation of nuclear factor (NF)-kappaB. Resistin induced a rapid increase in intracellular calcium concentration, mainly through calcium release from intracellular inositol triphosphate-sensitive pools. The intracellular calcium chelator BAPTA-AM blocked resistin-induced NF-kappaB activation and monocyte chemoattractant protein-1 expression. In conclusion, this study shows a role for resistin as an intrahepatic cytokine exerting proinflammatory actions in HSCs, via a Ca2+/NF-kappaB-dependent pathway and suggests involvement of this adipokine in the pathophysiology of liver fibrosis.
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PMID:Resistin as an intrahepatic cytokine: overexpression during chronic injury and induction of proinflammatory actions in hepatic stellate cells. 1714 67


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