低氧对人胚肺成纤维细胞表型与增生的影响

Effects of Hypoxia on Phenotype and Proliferation of Human Embryonic Lung Fibroblasts

采用单层细胞超薄切片技术和免疫细胞化学方法， 观察常氧（Ｎ）、低氧（Ｈ）、常氧和低氧猪肺动脉内皮细胞条件培养液（ＮＥＣＣＭ 和ＨＥＣＣＭ） 等不同条件， 对肺血管外膜成纤维细胞的表型与增殖的影响。结果表明： （１） 仅ＨＥＣＣＭ 组成纤维细胞显示表型转变，胞浆内出现微肌丝、致密体、基膜等平滑肌细胞超微结构，粗面内质网明显减少；且此组细胞α－平滑肌肌动蛋白（α－ＳＭＡ） 表达较其余３ 组明显增高（Ｐ＜ ０． ０１）； （２） Ｈ 和ＨＥＣＣＭ 组增殖细胞核抗原（ＰＣＮＡ） 表达较Ｎ 和ＮＥＣＣＭ 组明显升高（Ｐ＜ ０． ０１）。结果提示： （１） 低氧可经肺动脉内皮细胞介导， 引起人胚肺成纤维细胞向平滑肌样细胞转化，而单纯低氧无此作用；（２） 低氧可直接或经内皮细胞介导，刺激人胚肺成纤维细胞增殖。

Monolayer cell ultramicrotomy and immunocytochemistry were used to investigate the effects of normal oxygen (N), hypoxia (H), the media i.e. normoxic and hypoxic endothelial cell conditioned medium (NECCM and HECCM) on phenotype and proliferation of adventitial fibroblasts of the pulmonary vessels. The results showed: (1) Only the fibroblasts in the HECCM group displayed the phenotype modulation, i.e. the ultrastructural patterns characteristics of smooth muscle cells including abundant microfilaments inserting into dense bodies, basemembrane and decreased rough endoplasmic reticula. And the expression of α smooth muscle actin (α SMA) in this group was increased obviously as compared with the other three groups ( P <0 01); (2) The expression of proliferating cell nuclear antigen (PCNA) by the fibroblasts in groups of H and HECCM was higher than in the groups of N and NECCM ( P <0 01).It was concluded that: (1) Hypoxia can, mediated by pulmonary arterial endothelial cells (PAECs) but not directly, induce phenotype modulation of the fibroblasts, namely transforming to smooth muscle cell like cells. (2) Hypoxia can stimulate proliferation of human embryonic lung fibroblasts directly or mediated by PAECs.