Fat accumulation has been shown to play important roles in the development of obesity-related disorders such as atherosclerosis, diabetes mellitus and hypertension. Recent studies have shown that fat tissue is not a simple energy storage organ, but exerts important endocrine functions. These are achieved predominantly through release of adipocytokines, which include several novel molecules released by adipocytes like leptin, resistin, adiponectin or visfatin, as well as some more classical cytokines released possibly by inflammatory cells, like TNF-alpha and IL-6. Adipocytokines may affect cardiovascular, hepatic, muscular and metabolic function. In this review, the recent research work of adipocytokines will be discussed.
Adipokines ; physiology ; Adiponectin ; physiology ; Adipose Tissue ; chemistry ; physiology ; Humans ; Leptin ; physiology ; Resistin ; physiology

OBJECTIVE: To determine the effect of metformin and adiponectin on the proliferation of EC cells and the relationship between metformin and adiponectin. METHODS: The proliferation impact of different concentrations of metformin and adiponectin on two types of EC cells ishikawa (IK) and HEC-1B was confirmed by CCK-8 method. qRT-PCR and Western blot were used to detect the effect of different concentrations of metformin on the changes of adiponectin receptors (AdipoR1 and AdipoR2) of the EC cells both in mRNA and protein level and the role of compound C, an adenosine monophosphate-activated protein kinase (AMPK) inhibitor, on the above effects. RESULTS: (1) Both metformin and adiponectin could significantly promote the proliferation of endometrial cancer (EC) cells in a time and concentration dependent manner (P<0.05).(2)Metformin and adiponectin had synergy anti-proliferative effect on EC cells and the combination index (CI) value of IK cells was 0.906 34 and of HEC-1B cells was 0.827 65. (3)qRT-PCR was used to detect the mRNA levels of AdipoR1 and AdipoR2 after 5 mmol/L and 10 mmol/L metformin, respectively, stimulating IK and HEC-1B cells for 48 hours and the mRNA expressions of AdipoR1 and AdipoR2 were significantly increased when compared with the control group (0 mmol/L)(IK: AdipoR1 of 5 mmol/L and 10 mmol/L group: P<0.001,AdipoR2 of 5 mmol/L group: P<0.001; HEC-1B: AdipoR1 of 5 mmol/L group: P<0.001, 10 mmol/L group: P=0.023, AdipoR2 of 5 mmol/L group: P<0.001, 10 mmol/L group: P=0.024). When combined with compound C, the RNA levels of AdipoR1 and AdipoR2 were not different compared with the control group (0 mmol/L, P>0.05). (4) Western blot was used to detect the protein levels of AdipoR1 and AdipoR2 after 5 mmol/L and 10 mmol/L metformin, stimulating IK and HEC-1B cells for 48 hours and the protein level was significantly increased when compared with the control group (0 mmol/L)(IK: AdipoR1 of 5 mmol/L group: P=0.04, 10 mmol/L group: P=0.033, AdipoR2 of 5 mmol/L group: P=0.044, 10 mmol/L group: P=0.046; HEC-1B: AdipoR1 of 5 mmol/L group: P=0.04, 10 mmol/L group: P=0.049, AdipoR2 of 5 mmol/L group: P=0.043, 10 mmol/L group: P=0.035). When combined with compound C,the protein levels of AdipoR1 and AdipoR2 were not different compared with the control group (0 mmol/L, P>0.05). CONCLUSION We find that metformin and adiponectin have synergy anti-proliferative effect on EC cells. Besides, metformin can increase adiponectin receptors expressions of EC cells both in mRNA and protein levels and this effect is accomplished by the activation of AMPK signaling pathway.
Adiponectin/physiology* ; Cell Proliferation/drug effects* ; Endometrial Neoplasms/pathology* ; Female ; Humans ; Hypoglycemic Agents/pharmacology* ; Metformin/pharmacology* ; Receptors, Adiponectin ; Signal Transduction

The vascular endothelium is a dynamic structure responsible for the separation and regulated movement of biological material between circulation and interstitial fluid. Hormones and nutrients can move across the endothelium either via a transcellular or paracellular route. Transcellular endothelial transport is well understood and broadly acknowledged to play an important role in the normal and abnormal physiology of endothelial function. However, less is known about the role of the paracellular route. Although the concept of endothelial dysfunction in diabetes is now widely accepted, we suggest that alterations in paracellular transport should be studied in greater detail and incorporated into this model. In this review we provide an overview of endothelial paracellular permeability and discuss its potential importance in contributing to the development of diabetes and associated complications. Accordingly, we also contend that if better understood, altered endothelial paracellular permeability could be considered as a potential therapeutic target for diabetes.
Adherens Junctions ; Adiponectin ; Endothelium ; Endothelium, Vascular ; Extracellular Fluid ; Insulin ; Permeability ; Physiology ; Tight Junctions

Adiponectin ; Ghrelin ; physiology ; Growth Hormone-Releasing Hormone ; Humans ; Leptin ; Receptors, Ghrelin ; Resistin

The incidence and mortality rates of diabetes with cardiovascular complications are continually rising, and diabetic cardiovascular disease is becoming a major public health issue that threatens human health. Acute endothelial dysfunction and chronic cellular damage caused by diabetes are important risk factors for diabetic cardiovascular disease and related mortality. Adiponectin is an adipocyte-derived molecule with significant cytoprotective effects, including the protection against diabetes-induced vascular endothelial injury. Here we review the mechanisms of adiponectin protective effects on acute vascular endothelial dysfunction and chronic structural damage induced by diabetes.
Adiponectin ; physiology ; Cardiovascular Diseases ; complications ; Diabetes Mellitus ; pathology ; Endothelium, Vascular ; physiopathology ; Humans

For the regulation of energy balance in various internal organs including gut, pancreas and liver, visceral adipose tissue and brain perform important sensing and signaling roles via neural and endocrine pathway. Among these, adipose tissue has been known as a simple energy-storing organ, which stores excess energy in triglyceride. However, it became apparent that adipocytes have various receptors related to energy homeostasis, and secrete adipocytokines by endocrine, paracrine and autocrine mechanisms. In this review, basic roles of adipocytes in energy homeostasis and the correlation between adipocyte signals and digestive diseases are discussed.
Adipocytes/*metabolism ; Adipokines/*physiology ; Adiponectin/physiology ; Digestive System Diseases/*metabolism ; *Energy Metabolism ; Homeostasis ; Humans ; Leptin/physiology ; Peroxisome Proliferator-Activated Receptors/physiology ; Resistin/physiology ; Signal Transduction

BACKGROUNDAdiponectin is an adipokine with insulin-sensitising and anti-atherogenic properties. The aim of this study was to investigate whether low adiponectin levels predict the impairment of endothelial function in newly diagnosed type 2 diabetic patients in an 8-year prospective study.

METHODSIn the prospective study, we enrolled 133 newly diagnosed type 2 diabetic patients without subclinical atherosclerosis and gave them intensive therapy; the mean treatment period was 8 years. Intensive treatment was a stepwise implementation of behavior modification and pharmacological therapy targeting hyperglycaemia, hypertension, dyslipidaemia and obesity. We measured baseline circulating adiponectin with an enzyme-linked immunosorbent assay, endothelium-dependent and -independent vasodilation by high-resolution vascular ultrasound. At year 8, 102 patients were reexamined for endothelium-dependent and -independent vasodilation.

RESULTSSex-adjusted adiponectin level was positively correlated with endothelium-independent vasodilation both at baseline (r = 0.150, P = 0.043) and at year 8 (r = 0.339, P = 0.001), whereas no association was found between adiponectin and endothelium-dependent vasodilation. In a stepwise multivariate linear regression model, adiponectin was an independent predictor for impaired endothelium-independent vasodilation at year 8 (P = 0.001).

CONCLUSIONSPlasma adiponectin concentration was associated with endothelium-independent vasodilation and hypoadiponectinemia predicted the impairment of endothelium-independent vasodilation in newly diagnosed type 2 diabetic patients under multifactorial intervention. These data support the causative link of impairment of endothelium-independent vasodilation with hypoadiponectinemia.

Adiponectin ; blood ; Diabetes Mellitus, Type 2 ; blood ; physiopathology ; Endothelium, Vascular ; physiology ; Female ; Humans ; Male ; Middle Aged ; Prospective Studies ; Vasodilation ; physiology

Adipokines, the bioactive factors derived mainly from adipocytes, regulate pancreatic beta-cell function including insulin secretion, gene expression and apoptosis. In this review, we propose that adipokines influence beta-cell function through three interdependent pathways. The first is through regulating lipid and glucose metabolism in beta-cells. The second implicates the change of ion channel opening and closing in beta-cells. The third pathway is via the modification of insulin sensitivity of beta-cells. The endocrine function of adipocytes is dynamic, and the secretion of various adipokines changes under different metabolic conditions. During the progression from the normal state to obesity and to type 2 diabetes, adipokines contribute to the occurrence and development of beta-cell dysfunction in type 2 diabetes.
Adipocytes ; physiology ; Adiponectin ; physiology ; Animals ; Diabetes Mellitus, Type 2 ; physiopathology ; Glucose ; metabolism ; Humans ; Insulin ; pharmacology ; Insulin-Secreting Cells ; physiology ; Leptin ; physiology ; Lipid Metabolism

Adipose tissue is not simply a depot of energy, but is an active endocrine organ. The adipokines play an important role in the pathogenesis of metabolic syndrome. The proinflammatory adipokines secreted from expanded visceral adipose tissue directly induce insulin resistance and vascular injuries. A better understanding of the endocrine function of adipose tissue may lead to more rational therapy for metabolic syndrome.
Adiponectin ; physiology ; Adipose Tissue ; physiopathology ; Drug Design ; Leptin ; physiology ; Metabolic Syndrome ; drug therapy ; physiopathology ; Resistin ; physiology ; Tumor Necrosis Factor-alpha ; physiology

It is the intent of this investigation to gain an insight into the relationship of serum total adiponectin with polycystic ovary syndrome (PCOS) and insulin resistance. Fifty-eight PCOS patients were enrolled (29 with high serum insulin level and 29 without), at the same time, 29 non-PCOS women with normal weight were included as control. The influencing factors of total adiponectin, PCOS and insulin resistance were analyzed. The serum total adiponectin of PCOS patients and all participants were found to be negatively related to waist hip ratio (r = -0.39, r = -0.36) and InHOMA-IR (r = -0.53, r = -0.45), respectively. Adiponectin was not a protective factor of PCOS (P > 0.1), but it was that of PCOS-insulin resistance (OR = 0.81; 95% CI: 0.67-0.97; P = 0.02). LH/FSH (OR = 1.51; 95% CI: 1.16-1.96; P = 0.01) and InHOMA-IR (OR = 1.26; 95% CI: 1.10-1.44; P = 0.01) were risk factors of PCOS, and waist hip ratio was that of PCOS-insulin resistance (OR = 8.57; 95% CI, 2.14-34.30, P = 0.01). Adiponectin might influence fasting insulin and InHOMA-IR (B = -0.22, P = 0.001; B = -0.02, P = 0.002). These data signify that adiponectin is not directly related with PCOS, but it is related with PCOS-HL Adiponectin might participate in the pathophysiologic mechanism of PCOS by influencing insulin sensitivity.
Adiponectin ; blood ; Adult ; Female ; Humans ; Insulin Resistance ; physiology ; Polycystic Ovary Syndrome ; blood ; physiopathology ; Waist-Hip Ratio ; Young Adult