Insulin, dexamethasone and methylisobutylxanthine regulate PAI-1 gene expression in 3T3-L1 adipocytes

Purpose. To investigate the plasminogen activator inhibitor-1 (PAI-1) gene expression in mouse 3T3-L1 adipocyte and the differentiation of 3T3-L1 cells in vitro. Methods. The morphological changes in 3T3-L1 cells during differentiation has been observed, and the relatively quantitative RT-PCR was used to research the effect of insulin (Ins), dexamethasone (Dex) and methylisobutylxanthine (Mix) acting alone or in combination on PAI-1 mRNA production. Results. The findings demonstrated that Ins, Dex in combination boosted the significant increase in PAI-1 mRNA and acted synergistically at a certain concentration, suggesting that Ins and Dex stimulate the different signaling pathway in different way, and that the factors triggered in the two pathways may interact during the signaling process. Conclusions. Ins, Dex and Mix play a essential role in induction of 3T3-L1 cells, and Ins, Dex dramatically elevate the increase in PAI-1 mRNA level in fully differentiated adipocyte. These provide evidence to further establish a mechanism through which Ins and Dex regulate the PAI-1 gene expression in 3T3-L1 adipocytes.