Study of Resistin gene expression in peripheral blood mononuclear cell and its gene polymorphism in a small range population

MicroRNA-492 reverses high glucose-induced insulin resistance in HUVEC cells through targeting resistin

The development of atherosclerosis (AS) is a multifactorial process, in which elevated plasma resistin (a key factor leading to insulin resistance) levels play an important role. Emerging evidence indicate that microRNAs (miRNAs) are involved in AS; However, the regulation and function of miRNAs in response to AS remain poorly understood. Our study analyzed the effects of miR-492 on insulin resistance, endothelial activation, and resistin expression in apoE knock-out mice and human umbilical vein endothelial cells after high-glucose treatment and miR-492 mimics transfection. We also investigated the underlying molecular mechanisms. Our results showed that high glucose stress induced a significant decrease in miR-492 expression, with a remarkable upregulation of resistin expression. We then identified resistin as a novel direct target of miR-492 using 3′-UTR luciferase reporter assay. Histopathologic examination demonstrated that upregulation of miR-492 attenuated endothelial cells migration and lipid accumulation induced by high glucose stress. Further investigation demonstrated that the upregulation of p-STAT3, SOCS, and P-selectin activation induced by high glucose stress was attenuated by upregulation of miR-492. Together, our findings indicate that miR-492 contributes to insulin resistance and endothelial dysfunction induced by high glucose, via directly downregulating resistin expression, and involving STAT3 phosphorylation, SOCS, and P-selectin activation.

Stress and obesity as risk factors in cardiovascular diseases: a neuroimmune perspective

Obesity is now growing at an alarming rate reaching epidemic proportions worldwide thus increasing morbidity and mortality rates for chronic disease. But although we have ample information on the complications associated with obesity, precisely what causes obesity remains poorly understood. Some evidence attributes a major role to a low-grade chronic inflammatory state (neurogenic inflammation) induced in obesity by inflammatory mediators produced and secreted within the expanded activated adipocyte pool. Adipose tissue is an endocrine organ that secretes numerous adipose tissue-specific or enriched hormones, known as adipokines, cytokine-like molecules thought to play a pathogenic role in cardiovascular diseases. The imbalance between increased inflammatory stimuli and decreased anti-inflammatory mechanisms may depend on chronic stress. Hence the positive correlation found between stress, obesity and cardiovascular diseases. The chronic inflammatory state associated with insulin resistance and endothelial dysfunction is highly deleterious for vascular function. This review focuses on the proposed neuroimmunodulatory mechanisms linking chronic (psychological) stress, obesity and cardiovascular diseases.

The plasma level and gene expression of resistin in polycystic ovary syndrome

OBJECTIVES

To investigate the relationship between plasma resistin, polycystic ovary syndrome (PCOS), and insulin resistance (IR). To compare the mRNA level of resistin in mononuclear cells and monocyte-derived macrophages in women with PCOS and controls.

MATERIALS AND METHODS

Patients with PCOS and controls were enrolled and IR was considered as the stratified factor for subgroups. Fasting blood was collected to determine the levels of sex hormones, insulin, glucose, blood lipid, and resistin. Resistin gene expression was evaluated by quantitative real-time RT-PCR in mononuclear cells and monocyte-derived macrophages cultured with or without rosiglitazone for 96 h.

RESULTS

No significant difference of plasma resistin levels was found among PCOS-IR, PCOS-non-IR, control-IR, and control-non-IR groups. There were no significant differences in resistin mRNA expression between participants with and without PCOS and with and without IR. Resistin mRNA expression in monocyte-derived macrophages was higher than that in mononuclear cells (p = 0.04), and could be reduced by rosiglitazone (p < 0.001).

CONCLUSIONS

Plasma resistin does not correlate with normal weight PCOS or IR. Resistin gene expression in mononuclear cells and monocyte-derived macrophages in PCOS and IR is the same as controls. Further researches on the role of resistin in the pathogenesis of PCOS or IR should concentrate on the tissue level.

Adipose tissue: a motor for the inflammation associated with obesity

Obesity is a worldwide epidemic that continues to grow at an alarming rate. This condition increases the morbidity and mortality associated with both acute and chronic diseases. Some of the deleterious consequences of obesity have been attributed to its induction of a low-grade chronic inflammatory state that arises from the production and secretion of inflammatory mediators from the expanded pool of activated adipocytes. This review focuses on the mechanisms that underlie the proposed link between obesity and inflammation, and it addresses how obesity-induced inflammation may account for increased morbidity and mortality that is associated with a diverse group of diseases.