Ning Dong1, Bing Xu1, Hong Shi1, Xin Tang2. 1. Department of Ophthalmology Beijing Shijitan Hospital, Capital Medical University, Beijing, People's Republic of China. 2. Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin, People's Republic of China.
Abstract
PURPOSE: The purpose of this study was to characterize the inflammatory effect of amadori-glycated albumin (AGA) in cultured rat retinal ganglion cells (RGCs) and to further explore the potential mechanism of the anti-inflammatory effects of baicalein. METHODS: Primary rat retinal neurons were separated and cultured. The levels of monocyte chemotactic protein-1 (MCP-1) mRNA and soluble MCP-1 produced by RGCs in response to AGA were measured with quantitative reverse transcription-PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). In addition, the expression of microRNA-124 (miR-124) and histone deacetylases (HDACs) were detected in cultured rat RGCs by qRT-PCR in the presence or absence of baicalein. Luciferase reporter assays were used to validate the regulation of a putative target of miR-124. RESULTS: Amadori-glycated albumin stimulation increased the expression of MCP-1 and inhibited the expression of miR-124 in cultured rat RGCs. In addition, miR-124 directly controlled MCP-1 expression by binding directly to 3'-untranslated region (3'-UTR) of MCP-1. Next, we demonstrated that miR-124 expression was suppressed by HDACs and that treatment of RGCs with HDACs inhibitors increased miR-124 expression and decreased MCP-1 production. Furthermore, application of baicalein in RGCs attenuated AGA-induced MCP-1 expression and upregulated expression of miR-124 by controlling HDAC4 and HDAC5. CONCLUSIONS: Collectively, these data suggest that baicalein inhibits AGA-induced MCP-1 expression in retinal ganglion cells via a microRNA-124-dependent mechanism.
PURPOSE: The purpose of this study was to characterize the inflammatory effect of amadori-glycated albumin (AGA) in cultured rat retinal ganglion cells (RGCs) and to further explore the potential mechanism of the anti-inflammatory effects of baicalein. METHODS: Primary rat retinal neurons were separated and cultured. The levels of monocyte chemotactic protein-1 (MCP-1) mRNA and soluble MCP-1 produced by RGCs in response to AGA were measured with quantitative reverse transcription-PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). In addition, the expression of microRNA-124 (miR-124) and histone deacetylases (HDACs) were detected in cultured rat RGCs by qRT-PCR in the presence or absence of baicalein. Luciferase reporter assays were used to validate the regulation of a putative target of miR-124. RESULTS: Amadori-glycated albumin stimulation increased the expression of MCP-1 and inhibited the expression of miR-124 in cultured rat RGCs. In addition, miR-124 directly controlled MCP-1 expression by binding directly to 3'-untranslated region (3'-UTR) of MCP-1. Next, we demonstrated that miR-124 expression was suppressed by HDACs and that treatment of RGCs with HDACs inhibitors increased miR-124 expression and decreased MCP-1 production. Furthermore, application of baicalein in RGCs attenuated AGA-induced MCP-1 expression and upregulated expression of miR-124 by controlling HDAC4 and HDAC5. CONCLUSIONS: Collectively, these data suggest that baicalein inhibits AGA-induced MCP-1 expression in retinal ganglion cells via a microRNA-124-dependent mechanism.