FIGURE 4.

Hyperglycemia-induced methylglyoxal modification of HIF-1α reduces HIF-1 heterodimer formation and HIF-1α binding to the SDF-1 and VEGF promoters in hypoxic mouse dermal fibroblasts. a, nuclear extracts from hypoxic fibroblasts treated as indicated were isolated, immunoprecipitated (IP) with HIF-1α rabbit antibody, and immunoblotted (IB) with ARNT1 mouse antibody. 10% of nuclear extracts were immunoblotted with β-actin antibody as input control. The membrane was scanned and quantitated by the ODYSSEY Infrared Imaging System. b, quantitation of association of HIF1-α with ARNT1 in a. c and d, soluble chromatin was prepared from hypoxic fibroblasts treated as indicated and chromosomal immunoprecipitation was performed using antibody to HIF-1α. The DNA extracted from the respective immunoprecipitates was amplified by real-time PCR (qPCR) using primers that cover the SDF-1 (c) and VEGF promoters (d), respectively. ^*, p < 0.01 versus LG group. Data are expressed as mean ± S.E., n = 3.