RESUMO
Background Oxidative stress is a main cause of age-related macular degeneration (AMD).Lutein has a preventive role for AMD, but its antioxidant mechanism remains unclear.Objective Present study was to investigate the effect of lutein on oxidative stress of Müller cells and its signaling pathway.Methods Human Müller cells (human Müller cell strain) were cultured, and the cells at logarithmimic growth phase were incubated in 96 well plate overnightly.Oxidative stress cell models were established by adding 160 μmol/L H2O2, a median lethal dose for Müller cells.The models were divided into the model control group and 12.5,25.0,50.0 mg/L lutein groups,and the different concentrations of lutein were used to culture the cells for 24 hours, respectively.The routine cultured cells served as the blank control group.Growth of the cells was assayed by MTT method (absorbancy);the reactive oxygen species (ROS) content in the cells was assayed by flow cytometry;the mRNA and protein levels of nuclear factor-E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the cells were detected by quantitative real-time PCR and Western blot, respectively.Results The inhibitory effects on the cells were gradually enhanced with the increase of H2O2 concentrations,showing a significant difference among the groups (F =43.890,P＜0.01).A significant difference was found in apoptotic rate of the cells among the blank control group,model control group and 12.5,25.0,50.0 mg/L lutein groups (F =346.770, P =0.000) , and the apoptosis rate was significant elevated with the increase of lutein dose (all at P＜0.05).The ROS contents in the cells were 1.92±0.18,64.89±2.86,52.70±2.80,32.61 ±4.20 and 5.68 ± 1.35 in the blank control group, model control group and 12.5,25.0,50.0 mg/L group, respectively, with significant difference among the groups (F =324.900, P =0.000), and the ROS content was gradually reduced as the increase of lutein dose (all at P＜0.05).The relative mRNA and protein expressions of Nrf2 and HO-1 were remarkedly higher in the 12.5,25.0,50.0 mg/L lutein groups than those in the model control group (F =236.960,242.620,186.830,263.120, all at P =0.000) , and no significant difference was seen in the relative expression level of nuclear Nrf2 protein among the groups (F =1.790, P =0.210).Conclusions Lutein can induce the expression of antioxidant enzymes by inducing the expression of nuclear translocation of Nrf2 and consequently inhibit the oxidative stress status.
RESUMO
Pré-eclâmpsia é uma síndrome sistêmica caracterizada por intenso estado inflamatório e antiangiogênico. A fisiopatologia da pré-clâmpsia envolve alterações no processo de invasão trofoblástica, com consequente inadequado suprimento sanguíneo uterino e estresse oxidativo do tecido placentário. As alterações placentárias decorrentes desse processo levam à maior produção de sFlt-1, um receptor solúvel para as moléculas de VEGF e PlGF. O sFlt-1 impede com que VEGF e PlGF realizem suas funções na homeostase endotelial, culminando com disfunção dessas células. De uma maneira geral, os processos inflamatórios, de disfunção endotelial e estresse oxidativo estão interligados e agem de maneira sinérgica. Trabalhos recentes têm demonstrado que elevações nas concentrações séricas de sFlt-1 ocorrem 5 a 6 semanas antes das manifestações clínicas da pré-eclâmpsia. Concomitantemente, observa-se queda nas concentrações séricas de PlGF. Sendo assim, as dosagens séricas de sFlt-1 e PlGF têm sido sugeridas para o diagnóstico precoce de pré-eclâmpsia. Ademais, os conhecimentos adquiridos a respeito dos fatores antiangiogênicos proporcionam ainda a possibilidade de novas linhas de pesquisa sobre possíveis terapias para a pré-eclâmpsia. Neste artigo, foram revisados os aspectos inflamatórios e antiangiogênicos envolvidos na fisiopatologia da pré-eclâmpsia. Por fim, foram correlacionados esses aspectos com o risco elevado para doenças cardiovasculares apresentado por essas pacientes ao longo de suas vidas.
Preeclampsia is a systemic syndrome characterized by inflammatory and antiangiogenic states. The pathogenesis of preeclampsia involves deficient trophoblast invasion that is responsible for altered uterine blood flow and placental oxidative stress. The damaged placenta produces higher concentrations of sFlt-1, a soluble receptor for VEGF and PlGF that is released in the maternal circulation and is involved in endothelial dysfunction. Actually, all processes involved in inflammation, endothelial dysfunction and oxidative stress are strongly correlated and act in a synergistic way. Recent data have shown that an increase in serum concentrations of sFlt-1 initiates 5 to 6 weeks before the clinical manifestations of preeclampsia and these alterations correlate with a decrease in serum concentrations of PlGF. Therefore, both sFlt-1 and PlGF have been suggested to be useful for an early-diagnosis of preeclampsia. The knowledge about the role of antiangiogenic factors in the pathogenesis of preeclampsia has raised the possibility of a therapy involving these factors.In this article we revisited the pathogenesis of preeclampsia addressing its antiangiogenic and inflammatory states.In conclusion, we correlated these alterations with the higher risk for cardiovascular diseases presented by these women in future life.