Changes of Chemerin Production in Obese Patients with Different States of Carbohydrate Metabolism

Chemerin is an adipose tissue mediator involved in the regulation of many processes, including lipogenesis, inflammatory responses, etc. The role of chemerin in the development of insulin resistance still needs better understanding. The aim of the study was to investigate chemerin production in obese patients with different states of carbohydrate metabolism. The study included 155 patients with diagnosed obesity and 34 patients with overweight. The control group 1 consisted of 43 conditionally healthy donors without obesity. For comparison of the research data on evaluation of tissue-specific mRNA expression of the genes IL-6, TNF-α, RARRES2, (encoding IL-6, TNF-α, and chemerin, respectively) control group 2 consisting of 30 non-obese was also included into this study. The relative level of mRNA expression of the genes IL-6, TNF-α and RARRES2 (encoding IL-6, TNF-α and chemerin, respectively) was carried out using real time PCR. Concentrations of IL-6, TNF-α, and chemerin were measured in serum/plasma using an enzymelinked immunosorbent assay (ELISA). Significant differences were found in the plasma level of chemerin and tissue-specific patterns of RARRES2 gene expression in obese patients; these changes depended on the degree of obesity and the state of carbohydrate metabolism. Opposite associations between RARRES2 gene expression and expression TNF-α and IL-6 genes have been recognized in adipose tissues of different localization: in obese patients (BMI ≤ 40 kg/m²) without type 2 diabetes mellitus (DM2) they were negative, while in obese patients with DM2 diabetes they were positive. The recognized correlations between the plasma content of chemerin and the expression level of its gene in biopsies with various parameters of carbohydrate and lipid metabolism, and proinflammatory molecules indicate chemerin involvement in metabolic and immune processes in obesity.