The Role And Mechanism Of MiR-483-3p In Extracellular Matrix Production Of Human Trabecular Meshwork Cells

BACKGROUND & PURPOSE:Globally, glaucoma,which has in common a characteristic optic neuropathy with associated field loss for which elevated intraocular pressure(IOP) is regarded as the main risk factor, is the second leading cause of blindness. It has been proposed that excessive deposition of ECM at the deepest portion of the TM could be a main site of outflow resistance. This study investigated the effects of micro RNA-483-3p(mi R-483-3p) on ECM production, and underlie its regulatory mechanism in human trabecular meshwork cells(HTMCs) under oxidative stress.METHODS:The expression levels of ECM(fibronectin, laminin, collagen I) in HTMCs under oxidative stress were measured by Western blot. Changes of mi R-483-3p expression in HTMCs were evaluated by quantitative polymerase chain reaction(q PCR). After using lentivirus stably expressing pri-mi R-483, the effects of mi R-483-3p on the ECM were assessed by q PCR and Western blot. Smad4, the potential target of mi R-483-3p according to m RNA target-predicting algorithms, was confirmed by luciferase assay and Western blot. Furthermore, the effects of Smad4 knockdown on ECM expression were investigated by q PCR and Western blot.RESULTS:The m RNA and protein levels of ECM(fibronectin, laminin, collagen I) were upregulated in HTMCs induced by oxidative stress. The expression level of mi R-483-3p decreased in HTMCs under oxidative stress, and the ectopic expression of mi R-483-3p decreased the levels of ECM. In addition, mi R-483-3p targeted Smad4 through two binding sites, resulting in a decrease of Smad4 expression. Furthermore, knockdown of Smad4 reduced the levels of ECM in HTMCs.CONCLUSION:Micro RNA-483-3p has an inhibitory effect on ECM production in HTMCs through downregulating Smad4, which indicates that mi R-483-3p may serve as a potential therapeutic target in glaucoma.