The O-GlcNAc modification promotes terminal differentiation of human corneal epithelial cells
The O-GlcNAc modification promotes terminal differentiation of human corneal epithelial cells
复制标题
DOI：
10.1093/glycob/cwaa033
复制
发表时间：
2020-11-01
期刊：
影响因子：
4.3
通讯作者：
Argueso, Pablo
中科院分区：
文献类型：
--
作者：
McColgan, Nicole M.;Feeley, Marissa N.;Argueso, Pablo
O-连接的β-N-乙酰氨基葡萄糖(O-GlcNAc)对核蛋白和细胞质蛋白的动态修饰在真核细胞转录活性的调控中起着重要作用。在这里，我们报告了O-GlcNAc修饰通过促进粘蛋白的生物合成和屏障功能而有助于维持眼表上皮细胞的动态平衡。我们发现，人角膜上皮细胞分化的诱导刺激了O-GlcNAc向核蛋白和胞浆蛋白的整体转移。另一方面，炎症情况与眼表上皮细胞中O-GlcNAc转移酶的表达减少有关。分别针对O-GlcNAc转移酶或O-GlcNAc水解酶选择性抑制剂Thiamet G的小干扰RNA的功能丧失和功能获得研究表明，O-GlcNAc的存在是促进糖萼屏障功能所必需的。此外，我们发现Thiamet G在降低细胞旁通透性的同时，引发了MUC16表面表达和顶端上皮细胞面积的相关增加。总之，这些结果确认细胞内蛋白O-糖基化是促进人角膜上皮细胞终末分化的一种新途径。
Dynamic modification of nuclear and cytoplasmic proteins with O-linked beta-N-acetylglucosamine (O-GlcNAc) plays an important role in orchestrating the transcriptional activity of eukaryotic cells. Here, we report that the O-GlcNAc modification contributes to maintaining ocular surface epithelial homeostasis by promoting mucin biosynthesis and barrier function. We found that induction of human corneal epithelial cell differentiation stimulated the global transfer of O-GlcNAc to both nuclear and cytosolic proteins. Inflammatory conditions, on the other hand, were associated with a reduction in the expression of O-GlcNAc transferase at the ocular surface epithelia. Loss- and gain-of-function studies using small interfering RNA targeting O-GlcNAc transferase, or Thiamet G, a selective inhibitor of O-GlcNAc hydrolase, respectively, revealed that the presence of O-GlcNAc was necessary to promote glycocalyx barrier function. Moreover, we found that Thiamet G triggered a correlative increase in both surface expression of MUC16 and apical epithelial cell area while reducing paracellular permeability. Collectively, these results identify intracellular protein O-glycosylation as a novel pathway responsible for promoting the terminal differentiation of human corneal epithelial cells.