【摘要】 目的 探讨二氧叶酸还原酶(DHFR)是否参与了糖化终末产物(AGE)对牛视网膜毛细血管内皮细胞(BREC)氧化应激和凋亡的诱导。方法 用锥蓝排斥法观察AGE(200 mg/L)培养对BREC增殖的影响,膜联蛋白V染色检测细胞的凋亡;免疫荧光染色法检测氧自由基和过氧化硝基;同时免疫杂交法检测DHFR。结果 AGE培养2天后,DHFR的表达明显受抑(P<0.01),而氧自由基和过氧化硝基合成增加,同时凋亡和死亡细胞也明显增加。但过表达DHFR后,氧自由基和过氧化硝基均回复正常而凋亡细胞则显著减少。结论 AGE对视网膜内皮细胞增殖的抑制或者促凋亡作用,至少一部分是通过抑制DHFR表达并诱导一氧化氮合成酶(eNOS)解耦联和之后的氧化应激来实现的。更多还原

【Abstract】 Objective To investigate whether the dihydrofolate reductase(DHFR) is involved in the glycosylation end products(AGE) of bovine retinal capillary endothelial cells(BREC) induced oxidative stress and upoptosis.Methods Gone blue exclusion was used to examine the effect of AGE(200 mg/L) on HRP proliferation and Annexin V was used to measure apoptosis.Immunofluorescence staining was used to detect peroxynitrite and superoxide,while immunoblotting assay was used to examine the protein expression of DHFR.Results After 2 days treatment with AGE,DHFR expression was significantly inhibited(P < 0.01),but reactive oxygen species(ROS) and peroxynitrite were over produced.Meanwhile,apoplotic and dead cells both increased significantly.However,ROS and peroxynitrite production resumed back to normal level and apoplotic cells were reduced after DHFR overexpression.Conclusion The AGE induced proliferation inhibition or apoptosis in bovine retinal endothelial cell is partly due to inhibition of DHFR expression and subsequent eNOS uncoupling and oxidative stress.更多还原