Resumen:
Chemerin is a novel adipokine associated with obesity and insulin resistance. Alpha-Lipoic acid (alpha-LA) has shown beneficial properties on diabetes and obesity. The aim of this study was to examine the effects of alpha-LA on chemerin production in adipocytes in absence or presence of TNF-alpha, insulin and AICAR. The potential signaling pathways involved in alpha-LA effects on chemerin were also analyzed. Alpha-LA actions on chemerin were tested in differentiated 3T3-L1 adipocytes and in some cases in human subcutaneous and omental adipocytes. Chemerin mRNA levels were measured by RT-PCR and the amount of chemerin secreted to culture media was determined by ELISA. Alpha-LA induced a concentration-dependent inhibition on both chemerin secretion and mRNA levels in 3T3-L1 adipocytes. The AMPK activator AICAR and the PI3K inhibitor LY294002 dramatically abrogated both chemerin secretion and gene expression, and further potentiated the inhibitory effect of alpha-LA on chemerin secretion. Insulin was able to partially reverse the inhibitory action of alpha-LA on chemerin secretion. Alpha-LA also reduced basal chemerin secretion in both subcutaneous and omental adipocytes from overweight/obese subjects. Moreover, alpha-LA was able to abolish the stimulatory effects of the pro-inflammatory cytokine TNF-alpha on chemerin secretion. Our data demonstrated the ability of alpha-LA to inhibit chemerin production, an adipokine associated to obesity and metabolic syndrome, suggesting that
