干眼是由于泪液分泌异常，泪膜不稳定和眼表面炎症所致的一种普遍的、慢性的、多因素的疾病。EGF是重要的多肽有丝分裂原，EGFR是其细胞增殖和信号传导的受体。EGF／EGFR系统对角膜细胞的生存、增殖和分化至关重要。我们的前期研究表明，PKA-CREB和MEK-ERK信号通路参与α-MSH对干眼模型大鼠的眼表改善过程，降低促炎因子的表达，同时引起EGFR的增加。本课题试图通过将α-MSH作用于苯扎氯铵刺激后的人角膜上皮细胞，通过CCK-8、occludin染色、Annexin-V、划痕实验等确定α-MSH对角膜上皮细胞的保护作用。并运用EGFR抑制剂和shRNA阻断角膜上皮细胞EGF／EGFR信号通路，检测α-MSH的保护作用，western-blot检测EGFR和STAT3信号通路，进一步明确α-MSH对眼表抗炎及保护作用的机制，为临床治疗干眼提供新的思路和可供选择的方法。

Dry eye is a highly prevalent, chronic, and multifactorial disease，which pathogenic factors including tear secretion abnormalities, tear film instability, and ocular surface inflammation. EGF is an important polypeptide mitogen. As EGF’s receptor, EGFR is related with its cell proliferation and signal transduction. EGF / EGFR system is critical for corneal cell survival, proliferation, and differentiation. Our previous studies have shown that, PKA-CREB and the MEK-ERK signaling pathway involved in α-MSH ameliorating ocular surface dysfunctions and lesions in a scopolamine-induced dry eye model, and EGFR lever was increasing. In this project, we will use α-MSH on human corneal epithelial cells which is treated with benzalkonium chloride. We will investigate the effect of α-MSH on human corneal epithelial cells by CCK-8, occludin staining, Annexin-V, cell healing assay. Then block EGF / EGFR signaling pathway of corneal epithelial cells by EGFR inhibitors and shRNA. The change of EGFR and STAT3 signaling pathway will detect by western-blot. This is helpful for clearing the mechanisms of the protection of α-MSH on ocular surface and providing new ideas and alternative methods for the clinical treatment of dry eye.