低氧状态下黏着斑激酶对人肺动脉平滑肌细胞增殖的影响机制

目的 探讨低氧状态下黏着斑激酶(FAK)对人肺动脉平滑肌细胞(HPASMC)增殖的影响机制.方法 采用FAK寡核苷酸转染法对HPASMC进行低氧处理,免疫沉淀法测定胞质蛋白FAK、生长因子受体结合蛋白2(Grb2)及吻蛋白的活性,Western印迹法测定胞质蛋白FAK、Grb2及吻蛋白的蛋白表达,免疫组织化学法测定胞质FAK、Grb2及吻蛋白表达.结果 低氧处理后胞质FAK、Grb2及吻蛋白的活性增加.胞质FAK、Grb2及吻蛋白的蛋白表达值在低氧处理1.5 h时分别为43.4±1.4、69.7±1.9、59.3±1.6,在低氧处理24 h时分别为41.3±1.3、71.3±1.5、59.4±1.8,较常氧处理1.5 h(35.7±1.2、48.7±1.3、33.2±1.8)和24 h时(41.3±1.3、50.2±1.7、38.9±1.9)明显增加,差异均有统计学意义(均P＜0.05).免疫组织化学结果也显示低氧情况下胞质FAK、Grb2及吻蛋白的表达增强.结论 低氧状态下HPASMC增殖与胞质FAK、Grb2及吻蛋白有关.这些胞质蛋白在低氧情况下对细胞生长和分化具有调控作用.

Abstract：

Objective To explore the mechanisms of focal adhesion kinase (FAK) in the proliferation of human pulmonary artery smooth muscle cells (HPASMCs) under hypoxia.Methods Cultured HPASMCs were passively transfected with FAK oligonucleotides (ODNS) and under normoxia or hypoxia condition.They were divided into four groups:normoxia without fibronectin ( FN), normoxia with FN, hypoxia without FN, hypoxia with FN in vitro respectively.Cytoplasmic FAK, Grb2 and paxillin were observed simultaneously by immunoprecipitation and Western blot.In addition, the expressions of cytoplasmic FAK, Grb2 and paxillin were detected by immunocytochemical staining.Results Immunoprecipitation and Western blot demonstrated that cytoplasmic expressions of FAK, Grb2 and paxillin in HPASMCs increased in hypoxia with FN from 43.4 ± 1.4, 69.7 ± 1.9, 59.3 ± 1.6 to 35.7 ± 1.2, 48.7±1.3, 33.2±1.8 at 1.5 h (all P＜0.05), from41.3±1.3, 71.3 ±1.5, 59.4 ±1.8 to41.3±1.3, 50.2 ± 1.7, 38.9 ± 1.9 at 24 h respectively ( P ＜ 0.01, P ＜ 0.05, P ＜ 0.05).Immunocytochemistry staining showed that the cytoplasmic expressions of FAK, Grb2 and paxillin were enhanced in hypoxia with FN versus normoxia with FN.There were significant differences.Conclusion Hypoxia can induce the activation of cytoplasmic FAK, Grb2 and paxillin so as to regulate the migration, survival and proliferation of HPASMCs.

Mechanisms of focal adhesion kinase tn the proliferation of human pulmonary artery smooth cells under hypoxia

Objective To explore the mechanisms of focal adhesion kinase (FAK) in the proliferation of human pulmonary artery smooth muscle cells (HPASMCs) under hypoxia.Methods Cultured HPASMCs were passively transfected with FAK oligonucleotides (ODNS) and under normoxia or hypoxia condition.They were divided into four groups:normoxia without fibronectin ( FN), normoxia with FN, hypoxia without FN, hypoxia with FN in vitro respectively.Cytoplasmic FAK, Grb2 and paxillin were observed simultaneously by immunoprecipitation and Western blot.In addition, the expressions of cytoplasmic FAK, Grb2 and paxillin were detected by immunocytochemical staining.Results Immunoprecipitation and Western blot demonstrated that cytoplasmic expressions of FAK, Grb2 and paxillin in HPASMCs increased in hypoxia with FN from 43.4 ± 1.4, 69.7 ± 1.9, 59.3 ± 1.6 to 35.7 ± 1.2, 48.7±1.3, 33.2±1.8 at 1.5 h (all P＜0.05), from41.3±1.3, 71.3 ±1.5, 59.4 ±1.8 to41.3±1.3, 50.2 ± 1.7, 38.9 ± 1.9 at 24 h respectively ( P ＜ 0.01, P ＜ 0.05, P ＜ 0.05).Immunocytochemistry staining showed that the cytoplasmic expressions of FAK, Grb2 and paxillin were enhanced in hypoxia with FN versus normoxia with FN.There were significant differences.Conclusion Hypoxia can induce the activation of cytoplasmic FAK, Grb2 and paxillin so as to regulate the migration, survival and proliferation of HPASMCs.