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Abstract #109246 Published in IGR 24-1
The effect of ET1-CTGF mediated pathway on the accumulation of extracellular matrix in the trabecular meshwork and its contribution to the increase in IOP
Wang J; Rong Y; Liu Y; Zhu M; Chen W; Chen Z; Guo J; Deng C; Manyande A; Wang P; Zhang H; Xiang YInternational Ophthalmology 2023; 43: 3297-3307
PURPOSE: To investigate the effect of endothelin-1 (ET-1) in excessive accumulation of extracellular matrix (ECM) of the trabecular meshwork (TM) and its role in intraocular pressure (IOP) regulation. METHODS: Cultured human TM cells (HTMCs) were treated with ET-1, ET-1 + ETA receptor (ETAR) antagonist BQ123, ET-1 + ETB receptor (ETBR) antagonist BQ788. The expressions of fibronectin (FN) and collagen type IV (Col IV) were evaluated by western blotting and immunofluorescence. A time course effect of ET-1 on the transcription level of connective tissue growth factor (CTGF) was investigated by qRT-PCR. Next, the transcription level of CTGF was downregulated by using antisense oligodeoxynucleotide sequence. Then HTMCs were treated with ET-1, and the expression levels of FN and Col IV were evaluated by western blotting. In addition, by using an ex-vivo model of cultured anterior eye segment, we explored the effect of ET-1 on IOP changes and the expressions of FN and Col IV. RESULTS: In cultured HTMCs, the expressions of FN and Col IV were significantly increased after ET-1 treatment, which were blocked by the pretreatment of ETAR antagonist BQ123, rather than ETBR antagonist BQ788. Besides, the CTGF mRNA level increased significantly and reached a peak after 48 h of ET-1 treatment. However, the effect of ET-1 on increasing the expressions of FN and Col IV in HTMCs could be inhibited by the downregulation of CTGF. In an ex-vivo model, IOP increased significantly after ET-1 administration, which could be blocked by BQ123 but not by BQ788. Furthermore, elevated expressions of FN and Col IV in TM were observed after ET-1 perfusion, and could be inhibited by BQ123 pretreatment. CONCLUSION: Excessive ET-1 in aqueous humor could lead to the abnormal accumulation of FN and Col IV in TM via the ETA-CTGF pathway, thereby increasing IOP.
Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, Hubei, China.
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