Autophagy Activated Via HIF-1α To Protect Against Blue Light-mediated Damage In Human Retinal Pigment Epithelium Cells

Objective: The aim of this study was to explore the role of HIF-1α and autophagy in response to blue light damage in human retinal pigment epithelium(hRPE)cells,and the possible relationship between the two,it provides a new idea and theoretical basis for studying the pathological mechanism of age-related macular degeneration,preventing and treating diseases of light-induced retinal damage.Methods: The hRPE cells(ARPE-19 cell line)were cultured in the dark or under the LED blue light of(2000±500)Lux for 2h,4h,6h and 8h.The morphological changes were observed by inverted phase contrast microscope,the cell viability were detected by CCK-8,and the expression levels of autophagy markers and HIF-1α were determined by western blot and qPCR.The cell viability and expression levels of HIF-1α,BNIP3 and autophagy relative proteins in ARPE-19 cells under blue light for 8h were measured after pretreatment of 3-MA,Rapa and YC-1.Results: 1.After 4h exposed under the blue light,ARPE-19 cells began to swell,cells gap enlarged,transparent circle was seen around,cytoplasm showed vacuoles and nucleus shrank.The cell viability of all blue light groups decreased significantly,and the decrease was aggravated with the prolongation of light exposure time,whereas the degree of aggravation decreased(P<0.05).2.Beclin-1,LC3II/LC3 I and HIF-1α were significantly increased,whereas the expression of p62 was significantly inhibited in blue light groups,and the levels were related to the irradiation time,and reached the top at 8h(P<0.05).3.The viability of ARPE-19 cells could obviously reduced by autophagy inhibitor 3-MA,obviously increased by autophagy activator Rapa(P<0.05).4.The viability of ARPE-19 cells under blue light shows significantly decrease after pretreated with YC-1,and the decrease was correlated with the concentration of YC-1(P<0.05).5.The expression of HIF-1α,BNIP3,autophagy markers LC3II/LC3 I and Beclin-1 were downregulated and p62 expression was upregulated in YC-1 group(P<0.05).Conclusion:1.Damage would induced in ARPE-19 cells under blue light,and the damage was aggravated with the extension of illumination time,but the degree of aggravation was decreased.2.Autophagy in ARPE-19 cells were activated by blue light,and it have protective roles against blue light-induced injure.3.Blue light can induce the expression of HIF-1α in ARPE-19 cells cultured in vitro,and may be involved in the regulation of autophagy in ARPE-19 cells under blue light through the of HIF-1α/ BNIP3 pathway.