Low expression of MFN2 is associated with early unexplained miscarriage by regulating autophagy of trophoblast cells
Low expression of MFN2 is associated with early unexplained miscarriage by regulating autophagy of trophoblast cells
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DOI：
10.1016/j.placenta.2018.08.005
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发表时间：
2018-10-01
期刊：
影响因子：
3.8
通讯作者：
Su, Ping
中科院分区：
文献类型：
--
作者：
Cai, Hongcai;Chen, Li;Su, Ping
简介：流产是妊娠期常见的并发症。据报道，滋养层细胞中的线粒体融合蛋白2（MFN 2）缺陷是早期流产的重要原因。MFN 2可以调节线粒体自噬，尽管其机制尚不清楚。本研究旨在探讨MFN 2和自噬在早期不明原因流产中的作用。方法：采用免疫组化和Western blotting方法检测MFN 2在早期不明原因流产妇女绒毛组织中的表达。Western blotting检测自噬相关蛋白（ATG 5、BECLIN 1和LC 3）、MMP-2、MMP-9和整合素β 1的表达。免疫荧光法检测GFP-LC 3转染后自噬体的表达。应用JC-1测定线粒体膜电位，透射电镜观察线粒体超微结构。结果：免疫荧光分析显示，早期不明原因流产妇女绒毛组织中MFN 2含量明显低于正常妊娠组妇女。通过蛋白质印迹法观察到LC 3、ATG 5和BECLIN 1水平增加。转染MFN 2-siRNA后，滋养层细胞中MFN 2的水平降低，而LC 3、ATG 5和BECLIN 1的水平显著升高。透射电镜观察到自噬体增多，线粒体功能明显受损。结论：MFN 2表达降低导致线粒体功能障碍、自噬水平增加和滋养层细胞功能障碍，可能是早期不明原因流产的原因之一。
Introduction: Miscarriage is a common complication during pregnancy. Mitofusin-2 (MFN2) deficiency in trophoblastic cells is reported to be an important cause for early miscarriage. MFN2 can regulate mitochondrial autophagy, although the mechanisms remain unknown. This study aims to investigate the roles of MFN2 and autophagy in early unexplained miscarriage.Methods: Immunohistochemistry and western blotting were used to detect the MFN2 expression in villous tissues from women who had early unexplained miscarriage. Western blotting was used to detect the expression of autophagy-related proteins (ATG5, BECLIN1, and LC3), MMP-2, MMP-9, and integrin beta 1. Immunofluorescence was used to detect the expression of autophagosome after transfection with GFP-LC3. We used JC-1 to measure the mitochondrial membrane potential and transmission electron microscopy (TEM) to observe the ultrastructure of mitochondria. The levels of beta-hCG and progesterone in the trophoblast were determined by the chemiluminescence method.Results: Immunofluorescence analysis demonstrated that MFN2 in the villous tissues of women with early unexplained miscarriage was significantly lower than that of women in the normal pregnancy group. Increased levels of LC3, ATG5, and BECLIN1 were observed by western blotting. After transfection with MFN2-siRNA, the level of MFN2 decreased, whereas LC3, ATG5, and BECLIN1 levels increased significantly in the trophoblasts. More autophagosomes and significant impairment of mitochondrial function were observed by TEM. The levels of beta-hCG, progesterone, MMP-2, MMP-9, and integrin beta 1 were significantly reduced in the MFN2-siRNA group.Conclusion: Low expression of MFN2 leads to mitochondrial dysfunction, increased level of autophagy, and trophoblast cell dysfunction, which could be accounted for early unexplained miscarriage.