[Ulinastatin inhibits hypoxia-induced phenotype modulation of pulmonary artery smooth muscle cells by up-regulating PPAR-γ expression].

OBJECTIVE: To evaluate the effect of ulinastatin on hypoxia-induced phenotype modulation of pulmonary artery smooth muscle cells (PASMCs) and explore the underlying mechanism.

METHODS: Cultured PASMCs from SD rats were exposed to normoxic condition, normoxia with ulinastatin treatment, hypoxia, or hypoxia with ulinastatin treatment. After 24 h of exposures, the cells were examined for SM-α-actin and caplonin expressions with immunofluorescence assay and for cell migration with CCK-8 and3 H-TdR assays. Western blotting was used for detecting the expressions of PPAR-γ in the cells, and PPAR-γ-responsive firefly luciferase reporter was employed for measuring the transcriptional activity of PPAR-γ. The PPAR-γ inhibitor GW9662 was used to explore the mechanism of the inhibitory effect of ulinastatin on hypoxia induced-phenotype modulation of PASMCs by measuring the changes in cell proliferation and migration.

RESULTS: Ulinastatin obviously enhanced the expressions of SM-α-actin and calponin (P<0.05), inhibited the proliferation and migration (P<0.05), and up-regulated the expression of PPAR-γ in PASMCs exposed to hypoxia (P<0.05). Pretreatment of the cells with GW9662 abolished the effect of ulinastatin on hypoxia-induced phenotype modulation of PASMCs and enhanced the cell proliferation and migration (P<0.05).

CONCLUSION: Ulinastatin inhibits hypoxia-induced phenotype modulation of PASMCs from rats possibly by up-regulating the expression of PPAR-γ.