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| Generation of endostatin by matrix metalloproteinases and cathepsins in human limbo-corneal epithelial cells cultivated on amniotic membrane |
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| 作者：David Hu… 文章来源：Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan, Taiwan 点击数4065 更新时间：2006/7/11 18:08:55 文章录入：毛进 责任编辑：毛进 |
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| Purpose: Previously, we found that human limbo-corneal epithelial cells (HLCECs) secreted more endostatin (EN), a potent angiogenic inhibitor, when HLE are cultured on amniotic membrane (AM) (IOVS 45:2586, 2004). The purpose of this study is to understand proteolytic mechanism by which EN production is increased following cultivating HLCECs on AM
Methods: We examined the level of MMP-7, -9, cathepsin-B, -K, -L, and -V in the conditioned medium (CM) of HLCECs cultured on dish, on intact AM, and on denuded AM. MMP or cathepsin inhibitors were added into the HLCEC/DAM cultures, and exogenous cathepsins were added to the CM of HLCEC/DAM to see the effect of the generation of EN.
Results: We found that the level of MMP-7, cathepsin –B and -V were increased when HLE were cultured on DAM than on IAM and on dish only. Inhibition of cathepsin activity blocked the production of 20 kDa EN, while inhibition of MMP activity blocked the generation of all the 20, 26, and 28 kDa EN-related fragments. Finally, the production of EN in the CM of HLCEC/DAM was increased by exogenous cathepsins, with cathepsin V more potent than cathepsin B.
Conclusion: This is the first documentation that cathepsin V, a cornea-specific cathepsin, participates in the generation of EN, which may in turn help to maintain the avascularity of the cornea.
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