Wang Jing, Feng Yifan, Wang Yuping, Xiang Danni, Zhang Xi, Yuan Fei
Department of Ophthalmology, ZhongShan Hospital, Fudan University, Shanghai 200032, China.
Department of Ophthalmology, ZhongShan Hospital, Fudan University, Shanghai 200032, China.
Biochem Biophys Res Commun. 2017 Jun 3;487(3):740-747. doi: 10.1016/j.bbrc.2017.04.130. Epub 2017 Apr 24.
Transforming growth factor-beta2 (TGF-β2) induces Endothelial-Mesenchymal transition (EndoMT) and autophagy in a variety of cells. Previous studies have indicated that activation of autophagy might decrease TGF-β2 induced EndoMT. However, the precise role remains unclear. In the present study, we found that TGF-β2 could induce EndoMT and autophagy in human retinal microvascular endothelial cells (hRMECs). Activation of autophagy by Rapamycin or Trehalose could reduce the expression of Snail, demonstrating a role of autophagy in regulating Snail production both by transcriptional and post-transcriptional mechanism. Co-immunoprecipitation (CoIP) demonstrated that LC3 co-immunoprecipitated with Smad3 and western blot showed that autophagy inducers, Rapamycin and Trehalose, could decrease the phosphorylation level of Smad3. Therefore, our results demonstrate that autophagy counteracts the EndoMT process triggered by TGF-β2 by decreasing the phosphorylation level of Smad3.
转化生长因子-β2（TGF-β2）可在多种细胞中诱导内皮-间充质转化（EndoMT）和自噬。先前的研究表明，自噬的激活可能会减少TGF-β2诱导的EndoMT。然而，其确切作用仍不清楚。在本研究中，我们发现TGF-β2可在人视网膜微血管内皮细胞（hRMECs）中诱导EndoMT和自噬。雷帕霉素或海藻糖激活自噬可降低Snail的表达，表明自噬通过转录和转录后机制在调节Snail产生中发挥作用。免疫共沉淀（CoIP）表明LC3与Smad3共免疫沉淀，蛋白质免疫印迹显示自噬诱导剂雷帕霉素和海藻糖可降低Smad3的磷酸化水平。因此，我们的结果表明，自噬通过降低Smad3的磷酸化水平来对抗TGF-β2触发的EndoMT过程。
