成纤维细胞生长因子9抑制PDGF-BB诱导的肺血管平滑肌细胞表型转化

Fibroblast Growth Factor 9 Inhibits PDGF-BB-Induced Phenotypic Phenotype Switch of Pulmonary Vascular Smooth Muscle Cells

该研究探讨了成纤维细胞生长因子9(fibroblast growth factor 9,FGF9)在肺动脉高压(pulmonary arterial hypertension,PAH)及肺血管平滑肌细胞表型转化中的作用。建立野百合碱(monocrotaline,MCT)诱导的大鼠肺动脉高压模型,Western blot检测大鼠肺组织中FGF9的表达情况。血小板衍生生长因子-BB(platelet-derived growth factor BB,PDGF-BB)诱导肺动脉平滑肌细胞(pulmonary artery smooth muscle cells,PASMCs)表型转化,Western blot检测PASMCs中FGF9的表达情况。重组人成纤维细胞生长因子9(recombinant human fibroblast growth factor 9,rhFGF9)干预PASMCs,通过划痕实验检测细胞迁移能力,Western blot检测细胞表型相关蛋白[α平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)、骨桥蛋白(osteopontin,OPN)]、增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)及血小板衍生生长因子受体β(platelet-derived growth factor receptorβ,PDGFR-β)的表达水平。siRNA抑制FGF9后,Western blot检测PASMCs表型与PCNA蛋白水平。结果显示,大鼠肺组织及PASMCs中FGF9的表达显著降低(P<0.05);PDGFBB下调PDGFR-β与收缩表型标志物α-SMA的表达(P<0.05),同时上调PCNA与合成表型标志物OPN的表达(P<0.05),且细胞的迁移能力增加;rhFGF9抑制PDGF-BB诱导的细胞表型转化和细胞迁移,而不影响PCNA与PDGFR-β的表达;下调FGF9可降低α-SMA(P<0.05)的表达,而PCNA与OPN的表达无显著改变,即下调FGF9后,平滑肌细胞的收缩表型发生改变。总之,rhFGF9抑制PDGF-BB诱导的平滑肌细胞表型转化和迁移,下调FGF9能改变平滑肌细胞的收缩表型,提示FGF9可能参与肺动脉高压的病理过程。

The purpose of this study is to investigate the role of FGF9(fibroblast growth factor 9)in PAH(pulmonary arterial hypertension)and phenotype switch of pulmonary vascular smooth muscle cells.Rat model of pulmonary arterial hypertension was induced by MCT(monocrotaline),and the expression of FGF9 in lung tissue was detected by Western blot.PDGF-BB(platelet-derived growth factor-BB)induced phenotype switch of PASMCs(pulmonary artery smooth muscle cells)and then Western blot was used to detect the expression of FGF9.Exogenous rhFGF9(recombinant human fibroblast growth factor 9)interfered with PASMCs.Then scratch assay and Western blot were used to measure cell migration,the expression of phenotype-related proteins[α-SMA(α-smooth muscle actin),OPN(osteopontin)],PCNA(proliferating cell nuclear antigen)and PDGFR-β(plateletderived growth factor receptorβ),respectively.After knock-down of FGF9 by siRNA,Western blot was used to analyze the expression of phenotypic markers and PCNA of PASMCs.The results showed that the expression of FGF9 in the lung tissue and PASMCs of rats were significantly reduced(P<0.05).The expression of PDGFR-βandα-SMA(contractile phenotype marker)was down-regulated(P<0.05),while the protein levels of PCNA and OPN(synthetic phenotypic marker)were increased in PASMCs treated with PDGF-BB(P<0.05),and migration of PASMCs induced by PDGF-BB.The changes in cell migration and expression ofα-SMA and OPN were blocked by rhFGF9,while rhFGF9 did not affect the expression of PDGFR-βand PCNA.Knock-down of FGF9 reduced the expression ofα-SMA without affecting the expression of PCNA and OPN,which suggested that FGF9 was related to the contractile phenotype of PASMCs.In summary,rhFGF9 represses the phenotype switch and migration of PASMCs induced by PDGF-BB,and the contractile phenotype of PASMCs was regulated by silencing FGF9.Therefore,FGF9 may participate in the pathogenesis of PAH.