Resistin-binding peptide antagonizes role of resistin on white adipose tissue

Abstract

To investigate the direct effects of resistin and resistin-binding peptide (RBP) on lipid metabolism and endocrine function in adipose tissue. Rat white adipose tissue was cultured in vitro and incubated for 24 h with 30 ng/mL recombinant rat resistin protein (rResistin) or combined with RBP of varying concentrations(1x10(-12) mol/L, 1x10(-10) mol/L, 1x10(-8) mol/L). Free fatty acids (FFA) released into medium was measured by a colorimetric kit. The levels of protein secretion and mRNA expression of TNF-alpha and adiponectin were detected by ELISA kit and RT-PCR respectively. The levels of FFA released into medium were significantly increased after 24 h of exposure to rResistin, but significantly decreased after RBP was applied, although there was no difference between the 3 concentrations. The protein level and gene expression of TNF-alpha in adipose tissue were significantly increased after 24 h of exposure to rResistin, but only obviously decreased after incubated with 1x10(-8) mol/L RBP. The levels of protein secretion and mRNA expression of adiponectin in adipose tissue were significantly decreased after 24 h of exposure to rResistin, but increased after incubated with RBP with the higher concentrations. RBP can effectively antagonize the role of resistin on the lipid metabolism and endocrine function of adipose tissue.