Increased levels of chemerin and its receptor, chemokine-like receptor-1, in obesity are related to inflammation: tumor necrosis factor-α stimulates mRNA levels of chemerin in visceral adipocytes from obese patients

Abstract

BackgroundChemerin is a novel adipokine that regulates adipocyte development and metabolic function and glucose metabolism. Our aim was to determine the effect of chemerin and its receptor, chemokine-like receptor-1, in obesity-associated low-grade chronic inflammation, exploring its circulating and gene expression levels in obesity and the effect of weight loss and to analyze the effect of the stimulation with tumor necrosis factor-α in human visceral adipocytes at a University hospital. MethodsWe included 52 women (16 lean and 36 obese) in the present study. The plasma concentrations of chemerin and the expression levels of chemerin and its receptor in visceral adipose tissue were analyzed. The chemerin concentrations were also measured before and after weight loss achieved by Roux-en-Y gastric bypass (n = 26). ResultsThe circulating concentrations and visceral adipose tissue expression of chemerin were increased in obese patients (P < .01) and were associated with well-established markers of inflammation (P < .001). Gene expression levels of chemokine-like receptor-1 followed the same trend and were upregulated (P < .05) in human obesity. Elevated chemerin levels in obese patients did not change after Roux-en-Y gastric bypass weight loss. Tumor necrosis factor-α treatment significantly enhanced (P < .05) the mRNA levels of chemerin in human visceral adipocytes, but the gene expression levels of chemokine-like receptor-1 were not affected. ConclusionThe increased levels of chemerin in obesity and its positive association with inflammation suggest a role for this chemoattractant protein in the changes that take place in visceral adipose tissue in the presence of energy surplus, establishing a link between inflammation and the greater risk of the development of metabolic disease.