Effects of hypoxia on Gax gene expression and proliferation of rat pulmonary artery smooth muscle cells

Objective To explore the effects of hypoxia on the expression of Gax gene and proliferation of rat pulmonary arterial smooth muscle cells(PASMCs).Methods Under hypoxia(2.5%O_(2)) condition,the expression of Gax mRNA and protein in PASMCs of rat was detected by RT-PCR,immunocytochemistry and Western blotting.~(3)H-TdR incorporation was used to observe the PASMCs proliferation.Results The expression of Gax mRNA and protein in PASMCs treated by hypoxia was confirmed to decrease by RT-PCR,immunocytochemistry and Western blotting.Compared with that in the control group,Gax mRNA and protein level decreased significantly in hypoxia PASMCs.With prolongation of time of hypoxia,~(3)H-TdR incorporation in PASMCs was significantly higher at 6 h,and reached a maximum at 24 h.Conclusion Hypoxia can downregulate the expression of Gax mRNA and protein in PASMCs and induce PASMCs proliferation,implying that Gax gene might play an important role in hypoxia-induced PASMCs proliferation.