Changes in expression of transforming growth factor beta-1 during myogenic differentiation of pulmonary microvascular endothelial cells in rats with hepato-pulmonary syndrome

Abstract

Objective To investigate the changes in the expression of transforming growth factor beta-1 (TGF-β1) during differentiation of pulmonary microvascular endothelial ceils (PMVECs) into smooth muscle cells in rats with hepato-pulmonary syndrome (HPS).Methods Primary PMVECs were harvested from healthy adult SD rats of both sexes aged 3-4 months and inoculated in low-glucose DMEM culture medium (1(6/cm2 ) and randomly divided into 2 groups ( n =24 dishes each):control group ( group C) and HPS group.HPS was produced by chronic ligation of common bile duct.In group C serum obtained from normal rats was added to PMVECs,while in HPS group serum obtained from rats with HPS was added.The final concentration of serum was 10％.After being incubated for 24,48 and 72 h,the expression of SM-MHC,SM-α-actin and calponin protein and TGF-β1 mRNA and protein in PMVECs was determined by RT-PCR and Western blot analysis.Results The expression of SMMHC,SM-α-actin and calponin protein.was positive in HPS group whereas the expression of SM-α-actin and calponin protein was negative and the expression of SM-MHC protein was barely detectable in group C.The expression of SM-MHC,TGF-β1 mRNA and protein was significantly higher in HPS group than in group C.The expression of SM-MHC,SM-α-actin and calponin protein and TGF-β1 mRNA and protein was increasing with duration of incubation from T1 to T3 in group HPS.Conclusion TGF-β1 plays an important role in the myogenic differentiation of PMVECs in rats with HPS. Key words: Hepatopulmonary syndrome; Endothelial cells; Lung; Transforming growth factor betal ; Cell differentiation