NLRP3通过非炎症小体途径调控TGF-β诱导角膜上皮衰老的机理研究

Aging of the ocular surface and corneal epithelium causes major ocular surface disorders. Our initial findings showed that the expression of TGF-β was abnormally higher in the elderly corneal epithelium and TGF-β could induce senescence of normal corneal epithelial cells in vitro. More interestingly, we found NLRP3 expression was increased in response to TGF-β stimulation while the inflammasome components ASC and Caspase1 were unaffected during the senescence. TGF-β induced senescence was significantly decreased in mouse Nlrp3-/- corneal epithelial cells, suggesting a novel role for NLRP3 in TGF-β signaling independent of the inflammasome. This study will further investigate the effect and mechanism of NLRP3 in corneal epithelium senescence: ①Identify the abnormally higher expression of NLRP3 in senescent corneal epithelium; ② Identify the NLRP3 and inflammasome gene expression in corneal epithelial cells in response to TGF-β simulation; ③ Elucidate the role of NLRP3 in the corneal epithelial cells senescence induced by TGF-β; ④ Study the mechanism of NLRP3 involved in the TGF-β induced senescence. The purpose of this study is to enrich the knowledge of ocular surface and corneal epithelium senescence and provide the novel targets for the therapy of age-related ocular surface and cornea diseases.

眼表及角膜上皮衰老与多种眼表疾病密切相关，但衰老的机制尚未阐明。我们前期研究发现老龄供体角膜上皮中过量表达的TGF-β能够引起角膜上皮细胞的衰老，同时TGF-β能够明显上调NLRP3的表达，而炎症小体其他组分ASC和Caspase1的表达没有变化，Nlrp3缺失后明显削弱了TGF-β诱导的衰老，提示NLRP3可以通过一种新颖的非炎症小体依赖的途径调节角膜细胞的衰老进程。本课题拟对NLRP3在TGF-β诱导的角膜上皮衰老中的作用及机制展开研究：①系统鉴定NLRP3及炎症小体组分在衰老角膜上皮中的表达；②确证TGF-β对角膜上皮细胞NLRP3表达的影响以及炎症小体是否活化；③明确NLRP3的非炎症小体途径在TGF-β诱导角膜上皮细胞衰老中的作用；④研究NLRP3对TGF-β诱导衰老的调节机制。通过研究，为眼表及角膜上皮衰老的调控提供理论依据，并为防治临床衰老相关的眼表疾病提供干预靶点。

眼表及角膜上皮衰老与多种眼表疾病密切相关，但衰老的机制尚未阐明。我们前期研究发现老龄供体角膜上皮中过量表达的TGF-β能够引起角膜上皮细胞的衰老，本课题对NLRP3在TGF-β诱导的角膜上皮衰老中的作用及机制展开了进一步的研究：①明确了TGF-β通过诱导角膜细胞产生mtROS促进角膜细胞的衰老，mtROS清除剂NAC可以抑制TGF-β诱导的衰老；②确证了NLRP3在衰老角膜上皮中高表达；③确证了TGF-β上调角膜上皮细胞NLRP3的表达但NLRP3炎症小体没有活化；④明确了NLRP3通过非炎症小体途径对TGF-β-smad信号通路进行正向调节，进而协同促进TGF-β诱导的衰老进程。通过研究，为眼表及角膜上皮衰老的调控提供理论依据，并为防治临床衰老相关的眼表疾病提供干预靶点。