Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, NO 2, East Yinghua Road, Chaoyang District, Beijing, 100029, China; Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, NO 2, East Yinghua Road, Chaoyang District, Beijing, 100029, China; National Clinical Research Center for Respiratory Diseases, NO 2, East Yinghua Road, Chaoyang District, Beijing, 100029, China.
Department of Respiratory and Critical Care Medicine, Beijing Anzhen Hospital, Capital Medical University, NO 2, Anzhen Road, Chaoyang District, Beijing, 100029, China.
Exp Cell Res. 2020 May 1;390(1):111941. doi: 10.1016/j.yexcr.2020.111941. Epub 2020 Mar 5.
Endothelial-to-mesenchymal transition (EndMT) has been implicated in initiation and progression of pulmonary arterial hypertension (PAH). Gremlin-1 promotes vascular remodeling of PAH and mediates epithelial-mesenchymal transition, which is similar to EndMT. In the present study we investigated the potential role of gremlin-1 plays in EndMT of pulmonary artery endothelial cells (PAECs).
Immunofluorescence staining was performed to detect the expression of alpha smooth muscle actin (α-SMA) and von Willebrand factor (VWF). Migration and angiogenic responses of PAECs were determined by transwell assay and tube formation assay, respectively. Protein expression levels were determined by western blotting.
Gremlin-1 induced EndMT of PAECs in a phospho-smad2/3-dependent manner. This was characterized by the loss of platelet endothelial cell adhesion molecule 1 and an increase in protein levels of a-SMA, nerve-cadherin, and matrix metalloproteinase 2. It was also determined that gremlin-1 facilitated the migration and angiogenic responses of PAECs in a dose-dependent manner. Bone morphogenetic protein 7 (BMP-7) was found to attenuate gremlin-1-mediated EndMT, migration and angiogenesis of PAECs by inducing phosphorylation of Smad1/5/8 and suppressing phosphorylation of Smad2/3.
Gremlin-1 mediates EndMT in PAECs, and BMP-7 reverses gremlin-1-induced EndMT by an induction of p-Smad1/5/8 and suppression of p-Smad2/3.
内皮-间质转化（EndMT）参与了肺动脉高压（PAH）的发生和进展。Gremlin-1 促进 PAH 的血管重构，并介导上皮-间质转化，这与 EndMT 相似。在本研究中，我们研究了 Gremlin-1 在肺动脉内皮细胞（PAEC）EndMT 中的潜在作用。
通过免疫荧光染色检测α平滑肌肌动蛋白（α-SMA）和血管性血友病因子（VWF）的表达。通过 Transwell 测定法和管形成测定法分别测定 PAEC 的迁移和血管生成反应。通过 Western blot 测定蛋白表达水平。
Gremlin-1 以磷酸化-smad2/3 依赖的方式诱导 PAEC 的 EndMT。其特征在于血小板内皮细胞黏附分子 1 的丢失和 α-SMA、神经钙黏蛋白和基质金属蛋白酶 2 的蛋白水平增加。还确定 Gremlin-1 以剂量依赖性方式促进 PAEC 的迁移和血管生成反应。骨形态发生蛋白 7（BMP-7）通过诱导 Smad1/5/8 的磷酸化和抑制 Smad2/3 的磷酸化，减弱了 Gremlin-1 介导的 PAEC 的 EndMT、迁移和血管生成。
Gremlin-1 介导 PAEC 的 EndMT，BMP-7 通过诱导 p-Smad1/5/8 和抑制 p-Smad2/3 来逆转 Gremlin-1 诱导的 EndMT。
