Sonic hedgehog expression and role in healing corneal epithelium
Sonic hedgehog expression and role in healing corneal epithelium
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DOI：
10.1167/iovs.04-0001
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发表时间：
2004-08-01
影响因子：
4.4
通讯作者：
Kao, WWY
中科院分区：
文献类型：
--
作者：
Saika, S;Muragaki, Y;Kao, WWY
目的.探讨Sonic hedgehog（Shh）在角膜上皮愈合过程中的表达及其作用。应用免疫荧光染色和Western印迹分析方法检测了Wistar大鼠角膜上皮缺损后不同时间点Shh、patched 1（Ptc 1）受体和Gli转录因子的表达。外源性Shh对细胞增殖和细胞周期蛋白D1表达的影响在器官培养的小鼠眼愈合角膜上皮中测定。未损伤的大鼠角膜上皮不被抗Shh抗体标记，但Ptc 1呈弱阳性。角膜缘和结膜上皮的基底细胞用抗Shh和Ptc 1抗体标记。Shh蛋白在清创后2 h在角膜缘上皮中瞬时表达上调，在移行的角膜上皮中也瞬时表达，高峰出现在清创后12 h。Shh表达的这种上调与Gli-3的瞬时核转位相关，而不解除体内清创后迁移上皮细胞增殖的抑制。然而，在培养液中加入Shh蛋白可导致细胞周期蛋白D1在细胞核中的积累，并显著加速器官培养小鼠眼角膜上皮细胞的增殖。角膜上皮清创导致Shh表达的瞬时上调和Shh/Gli-3信号级联在愈合的角膜和角膜缘上皮中的激活。虽然外源性Shh促进角膜器官培养中的上皮细胞增殖，但其在体内迁移上皮中的表达并不抵消上皮清创早期愈合阶段的细胞增殖抑制。
PURPOSE. To examine the expression pattern and roles of Sonic hedgehog (Shh) in healing corneal epithelium.METHODS. Immunofluorescent staining and Western blot analysis were used to detect Shh, patched 1 (Ptc 1) receptors, and Gli transcription factors in corneal epithelium of Wistar rats (n = 44) at various intervals after an epithelial defect. Effects of exogenous Shh on cell proliferation and cyclin D1 expression were determined in healing corneal epithelium of organ-cultured mouse eyes.RESULTS. Uninjured rat corneal epithelium was not labeled by anti-Shh antibody, but weakly positive for Ptc 1. Basal cells of limbal and conjunctival epithelia were labeled by antibodies against Shh and Ptc 1. Shh protein was transiently upregulated in limbal epithelium in 2 hours and was also transiently expressed in the migrating corneal epithelium with its peak at 12 hours postdebridement. Such upregulation of Shh expression was associated with a transient nuclear translocation of Gli-3 without lifting the suppression of cell proliferation in migrating epithelium postdebridement in vivo. However, an addition of Shh protein to culture medium resulted in nuclear accumulation of cyclin D1 and marked acceleration of epithelial cell proliferation in migrating corneal epithelium of an organ-cultured mouse eye.CONCLUSIONS. Corneal epithelial debridement causes a transient upregulation of Shh expression and activation of Shh/Gli-3 signaling cascade in healing corneal and limbal epithelia. Although exogenous Shh promotes epithelial cell proliferation in corneal organ culture, its expression in migrating epithelium in vivo does not counteract the suppression of cell proliferation at the early healing phase of epithelium debridement.