Up-regulation of caveolin-1 by DJ-1 attenuates rat pulmonary arterial hypertension by inhibiting TGFβ/Smad signaling pathway
Up-regulation of caveolin-1 by DJ-1 attenuates rat pulmonary arterial hypertension by inhibiting TGFβ/Smad signaling pathway
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DOI：
10.1016/j.yexcr.2017.10.019
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发表时间：
2017-12-01
影响因子：
3.7
通讯作者：
Fa, Xian'en
中科院分区：
文献类型：
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作者：
Gao, Weiwei;Shao, Runxia;Fa, Xian'en
肺动脉高压（PAH）是以肺动脉平滑肌细胞（PASMCs）过度增殖和凋亡抵抗为特征的疾病，与血管活性介质失衡和肺血管大量重构密切相关。DJ-1/park 7是一种多功能蛋白，在转录调控、抗氧化应激和肿瘤形成等细胞生物学活动中起着重要的防御作用。本研究探讨DJ-1对缺氧性肺动脉高压模型大鼠及肺动脉平滑肌细胞的影响及其可能的分子机制。首先，采用Western blot方法，同步检测肺动脉高压模型大鼠肺组织和低氧诱导的PASMCs中DJ-1和Caveolin-1（Cav-1）的低表达。然后，将DJ-1野生型（WT）或敲除（KO）大鼠暴露于慢性缺氧以模拟缺氧PAH条件。DJ-1 KO大鼠组织中Cav-1蛋白水平明显降低，DJ-1 WT和KO大鼠缺氧组Cav-1蛋白水平低于常氧组。在体内，血流动力学数据显示，DJ-1 KO组PAH模型大鼠的肺动脉压（mPAP）、右心室收缩压（RVSP）和肺动脉收缩压（PASP）以及右心室/左心室加室间隔重量（RV/LV + S）比值均高于DJ-1 WT组。此外，DJ-1的敲除还导致PASMC从收缩型向合成型的表型转换，这通过降低的钙调蛋白和SM 22 a表达来反映。在体外，DJ-1过表达逆转了缺氧诱导的PASMC细胞增殖、迁移和Ca 2+浓度升高，而在Cav-1 shRNA（sh-Cav-1）和DJ-1共转染的PASMC细胞中，上述作用不明显。然后在DJ-1组中检测到增加的calponin和SM 22 a水平;类似地，在DJ-1 + sh-Cav-1组中这些水平没有改变。Ad-DJ-1组TGF β 1、p-Smad 2和p-Smad 3表达明显降低，而DJ-1和sh-Cav-1共转染组TGF β 1、p-Smad 2和p-Smad 3表达均升高。结论：DJ-1可能通过抑制TGF β/Smad信号通路减轻Cav-1对缺氧诱导的PASMCs的损伤。
Pulmonary arterial hypertension (PAH), characterized by excessive proliferation and apoptosis resistance of pulmonary artery smooth muscle cells (PASMCs), is closely associated with the imbalance in vasoactive mediators and massive remodeling of pulmonary vasculature. DJ-1/park7, a multifunctional protein, plays a critical defense role in several cytobiological activity, such as transcriptional regulation, anti-oxidative stress and tumor formation. In this study, we investigated the effects of DJ-1 on hypoxia-induced PAH model rats and PASMCs, as well as its possible molecular mechanism. First, the low expressions of DJ-1 and caveolin-1 (Cav-1) were synchronously detected in lung tissue of PAH model rats and hypoxia-induced PASMCs by Western blot. Then, the DJ-1 wild type (WT) or Knock out (KO) rats were exposed to chronic hypoxia to mimic a hypoxic PAH condition. The protein level of Cav-1 was markedly decreased in the tissue of DJ-1 KO rats, and additionally lower in tissue of the hypoxia group than that in the normoxia group for DJ-1 WT and KO rats. In vivo, hemodynamic data showed that the pulmonary arterial pressure (mPAP), right ventricle systolic pressure (RVSP) and pulmonary arterial systolic pressure (PASP), as well as the weight of the right ventricle/left ventricle plus septum (RV/LV + S) ratio of PAH model rats were higher in the DJ-1 KO group than those in the DJ-1 WT group. Moreover, knockout of DJ-1 also results in the phenotype switch from contractile to synthetic PASMC, which is reflected by reduced calponin and SM22a expressions. In vitro, DJ-1 overexpression reversed hypoxia-induced elevation of PASMC cell proliferation, migration and Ca2+ concentration, which were not obviously observed in Cav-1 shRNA (sh-Cav-1) and DJ-1 co-transfected cells. Then the increased levels of calponin and SM22a were detected in the DJ-1 group; similarly those levels were not changed in the DJ-1 + sh-Cav-1 group. Finally, the expression of TGF beta 1, p-Smad2 and p-Smad3 were obviously decreased in the ad-DJ-1 group, however those were all elevated in the DJ-1 and sh-Cav-1 co-transfected groups. In conclusion, these results indicate that DJ-1 may alleviate hypoxia-induced PASMCs injury by Cav-1 through inhibiting the TGF beta/Smad signaling pathway.