Effects of long-term cigarette smoke exposure on pulmonary vascular re-modeling and TGF-β1 expression in rat pulmonary vessels / 中国病理生理杂志

ABSTRACT

[ ABSTRACT] AIM:To observe the effects of long-term cigarette smoke exposure on pulmonary vascular remode-ling and the protein expression of transforming growth factor-β1 ( TGF-β1 ) in the rats, and to explore the mechanism. METHODS:SD rats (n=36) were randomly divided into control group, 2-week smoke exposure (S-2W) group and 12-week smoke exposure (S-12W) groups.HE staining andα-smooth muscle actin staining were performed to observe the pul-monary vascular remodeling.The protein expression of proliferating cell nuclear antigen ( PCNA) and TGF-β1 in the pulmo-nary arteries was determined by the method of immunohistochemistry.The mRNA expression of TGF-β1 in the pulmonary arteries was evaluated by RT-qPCR.RESULTS:Compared with control group, ratio of pulmonary vessel wall thickness to vessel diameter ( WT%) and percentage of muscularized vessels were significantly increased in S-2W group and S-12W group ( P<0.01) .Significant increases in the protein expression of PCNA and TGF-β1 in smoke exposure groups were ob-served compared with control group.There was significant difference between 2 model groups (P<0.01).Compared with control group, the mRNA expression of TGF-β1 in pulmonary artery walls obviously increased in smoke exposure groups. There was significantly difference between S-2W and S-12W groups (P<0.05).The mRNA expression of TGF-β1 was positively correlated with pulmonary vascular muscularization, WT% and the protein expression of PCNA.CONCLU-SIONLong-term cigarette smoke exposure results in pulmonary artery remodeling in rats.The possible mechanism is that cigarette smoking exposure induces the over-expression of TGF-β1 at mRNA level in pulmonary vessels and promotes the proliferation of pulmonary vascular smooth muscle cells in rats.