Glaucine inhibits hypoxia-induced angiogenesis and attenuates LPS-induced inflammation in human retinal pigment epithelial ARPE-19 cells

Abstract

Glaucine is an aporphine alkaloid with anti-inflammatory, bronchodilator and anti-cancer activities. However, the effects of glaucine in the regulation of age-related macular degeneration (AMD) remain unclear. Herein, we aimed to investigate the anti-angiogenetic and anti-inflammatory effects of glaucine in ARPE-19 cells. ARPE-19 cells were treated with N-(methoxyoxoacetyl)-glycine, methyl ester (DMOG) and cobalt chloride (CoCl2) for induction of hypoxia, while lipopolysaccharide (LPS) treatment was used for elicitation of inflammatory response. Cell viability was analyzed using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. The expression of hypoxia-inducible factor (HIF-1α) and vascular endothelial growth factor (VEGF) were measured by Western blot. The secretion of VEGF, interleukin (IL)-6 and monocyte chemoattractant protein-1 (MCP-1) was detected using enzyme-linked immunosorbent assay (ELISA). Human umbilical vein endothelial cells (HUVECs) were used for tube formation analysis. Expression of HIF-1α and secretion of VEGF were significantly increased under DMOG and CoCl2 induction, whereas glaucine significantly attenuated both HIF-1α expression and VEGF secretion by DMOG- and CoCl2-induced ARPE-19 cells. In addition, glaucine suppressed the tube formation by DMOG- and CoCl2-induced HUVEC cells. Moreover, glaucine also attenuated the production of IL-6 and MCP-1 by LPS-induced ARPE-19 cells. This study indicated that glaucine exhibited anti-angiogenic and anti-inflammatory effects, suggesting that glaucine might have benefits for the treatment of AMD.