The Effect of IGFBP-3 on Adipokines and Gene Expression in Differentiated 3T3-L1 Adipocytes / 대한소아내분비학회지

ABSTRACT

PURPOSE: IGFBP-3 leads to the induction of insulin resistance in 3T3-L1 adipocytes. We carried out a series of experiments to elucidate the effects of IGFBP-3 on adipokines and gene expressions. METHODS: We treated fully-differentiated 3T3-L1 adipocytes with IGFBP-3 (0.5, 1, and 2 microg/mL) for one day and measured the mRNA levels of adiponectin, leptin, resistin, and TNF-alpha by RT-PCR, and adiponectin, leptin, resistin, and IL-6 protein levels in the culture supernatant were measured using multiplex adipokine assay ELISA Kits (Linco Research, St. Charles, Missouri). Gene expression in 3T3-L1 adipocyte cells using a microarray method was performed. RESULTS: IGFBP-3 inhibited the expression of adiponectin, leptin, resistin, and TNF-alpha mRNA. IGFBP-3 at 0.5 and 1 micro/mL decreased adiponectin release, but IL-6 release was increased at 2 micro/mL IGFBP-3. A dose-dependent inhibition of leptin was released by IGFBP-3 at 50%. Resistin release was decreased by 40%. The effect of IGFBP-3 on the gene expression in 3T3-L1 adipocyte cells using a microarray assay related to an increase of agouti-realted proteins (Agrp) and Janus kinase 2 (JAK2), and a decrease of the ras homolog gene family (Rhoq), acyl-CoA synthetase long-chain family member 6 (Acsl6), and the interleukin-1 receptor-associated kinase 1 (Irak1). CONCLUSION: IGFBP-3 regulates several adipokines gene expressions that are known to modulate insulin sensitivity, and this regulation may be attributable to the insulin resistance effect of IGFBP-3 on adipocytes.