Objective: To investigate whether nonenzymatic glycated end products (AGEs) have effects on the expression and bioactivity of plasminogen activator inhibitor-1 (PAI-1), one of the seripin proteinases, which lead to extracellular matrix (ECM) degradation in cultured human mesangial cells.
Methods: Human mesangial cells (HMC) were cultured. Cell proliferation, fibronectin production, mRNA expression and bioactivity of PAI-1 were determined after exposure to AGE-BSA for 24 hours and 48 hours in vitro.
Results: HMC stimulated by AGE-BSA exhibited inhibition in HMC proliferation, increase in fibronectin production, and PAI-1 bioactivity. These changes were pronounced with prolongation of experimental time. PAI-1 mRNA expression increased significantly at 24 hr (0.45% +/- 0.06% vs 0.65% +/- 0.08%, P < 0.05), however more marked increase of PAI-1 mRNA expression at 48 hr (0.51 +/- 0.08% vs 0.92 +/- 0.10%, P < 0.01).
Conclusions: Increase of mRNA expression and bioactivity of PAI-1 induced by AGEs decreased ECM degradation and play an important role in the pathogenesis of ECM accumulation and glomerulosclerosis.