The Protective Effect Of ApoM On Human Retinal Endothelial Cells Under High Glucose

BACKGROUND & OBJECTIVE: Diabetic retinopathy(DR)is one of the most serious complications of diabetes mellitus(DM),and its incidence is closely related to the duration of DM.DR is the leading cause of blindness in the working population,which seriously affects the quality of life of patients.In recent years,with the improvement of people's living standard and the change of life style,the incidence of DR has been increasing year by year,and the cost of medical care has also brought a serious social problem.However,the pathogenesis of DR has not yet fully elucidated,the classic DR pathogenesis include: inflammation and immune factors,oxygen free radicals and oxidative stress,polyadenyl diphosphate ribosyl polymerase activation,polyol pathway,protein kinase C activation and so on.In the recent years,more and more studies have proposed chronic inflammation and unified pathway theory,put forward a new direction for the pathogenesis of DR.Apolipoprotein M(apoM)is a human apolipoprotein found by Xu and Dahlb?ck and isolated and cloned from plasma triglycerides,mainly in human plasma high density lipoprotein(HDL).Current studies have shown that apoM may be associated with cardiovascular disease such as diabetes,obesity,coronary heart disease and so on.The aim of this study was to investigate the changes of apoM and inflammatory cytokines in human retinal endothelial cells(hRECs)and the protective effect of apoM on hRECs under high glucose environment.Methods:1.The mRNA expression levels of apoM,MCP-1 and TNF-? were detected by RT-PCR after hRECs were incubated for 24 h in normal(5.5 mM)and high glucose(30 mM)environments.2.The hRECs were infected with the No-load lentivirus and the lentivirus containing the apoM sequence,the m RNA and protein expression levels of apoM were detected by RT-PCR and Western blot in normal(5.5mM)and high glucose(30mM)environments.3.The cells in the No-load group and the apoM overexpressing group were treated with high glucose(30 mM)for 24 h.The expression levels of MCP-1 and TNF-? were detected by RT-PCR.Results:1.Compared with the normal glucose concentration,the mRNA expression of apoM,MCP-1 and TNF-? in the high glucose group was significantly increased(P<0.05).2.After overexpression of apoM,the mRNA and protein levels of apoM in hRECs were significantly increased(P<0.05).Compared with normal glucose concentration,the protein expression of apoM was significantly increased in overexpression group in the high glucose environment(P<0.05).3.In the high glucose environment,the mRNA expression levels of MCP-1 and TNF-? in apoM overexpression group were significantly lower than that in No-load group(P<0.05).Conclusions:1.Early high glucose environment promoted the mRNA expression levels of apoM,MCP-1 and TNF-? in hRECs.2.Compared with the No-load group,apo M mRNA and protein levels of overexpression group were significantly improved,suggesting that the infection of lentivirus is successful.At the same time,high glucose promoted the protein expression of apoM in apoM overexpression group.3.In the high glucose environment,overexpression of apoM may inhibit the expression levels of MCP-1 and TNF-?,thus protecting the retinal endothelial cells,involved in the development and progression of diabetic retinopathy.