姜黄素通过抑制PI3K/Akt信号通路改善LPS诱导的视网膜炎症

Curcumin alleviates LPS-induced retinal inflammation by inhibiting PI3k/Akt signaling pathway

目的:本研究旨在调查姜黄素是否能减轻动物模型和人视网膜色素上皮细胞(ARPE)-19细胞的视网膜炎症。方法:在体内,雄性C57/B6小鼠腹腔注射姜黄素3d,然后腹腔注射脂多糖(LPS;10mg/kg)诱导视网膜炎症。LPS作用24h后,通过RT-PCR检测促炎细胞因子的mRNA水平。伴刀豆球蛋白凝集素灌注标记技术评估了白细胞对视网膜脉管系统的粘附。用蛋白质定量试剂盒测量前房中的蛋白浓度。在体外,培养ARPE-19细胞。用细胞计数试剂盒8(CCK-8)法测量来选择姜黄素的最佳作用浓度。在用5μg/mL LPS刺激之前,将ARPE-19细胞在有或没有姜黄素的情况下孵育1h。通过RT-PCR和ELISA测量促炎细胞因子。通过蛋白质印迹分析PI3K/Akt表达。结果:姜黄素预处理可显著抑制EIU相关白细胞粘附于视网膜血管和前房蛋白渗漏。体内应用姜黄素后,炎症细胞因子(如IL-1β,IL-6和TNF-α)的mRNA表达水平也显著降低。同时,姜黄素在ARPE-19细胞的mRNA和蛋白质水平上均显著减弱IL-6,IL-8和MCP-1的表达。姜黄素抑制LPS激活的ARPE-19细胞中的PI3K/Akt磷酸化以及NF-κB激活。结论:姜黄素对LPS诱导的视网膜炎症具有预防作用,其作用似乎与PI3k/Akt信号传导途径的抑制有关。

·AIM:To investigate whether the curcumin reduce retinal inflammation in animal model and human retinal pigment epithelium(ARPE)-19 cells.·METHODS:In vivo,male C57/B6 mice received intraperitoneal injections of curcumin for 3 d before intraperitoneal injection of lipopolysaccharide(LPS;10 mg/kg) to induce retinal inflammation.24 h after LPS application,the mRNA levels of pro-inflammatory cytokines were detected by real-time PCR(RT-PCR).Concanavalin A lectin perfusion-labeling technique evaluated leukocyte adhesion to the retinal vasculature.The protein concentration in the anterior chamber was measured with a protein quantification kit.In vitro,ARPE-19 cells were cultured.The optimum concentration of curcumin was detected by cell counting kit-8(CCK-8)assay.Before stimulated with 5 u g/mL LPS,ARPE-19 cells were incubated with or without curcumin for 1 h.Proinflammatory cytokines were measured by RT-PCR and ELISA.PI3 K/Akt expression was analyzed by Western Blotting.·RESULTS:Curcumin pre-treatment led to significant inhibition of EIU-associated leukocyte adhesion to retinal blood vessels and anterior-chamber protein leakage.The mRNA expression level of inflammatory cytokines was also significantly reduced with application of curcumin in vivo,such as IL-1β,IL-6 and TNF-α.Meanwhile,Curcumin significantly attenuated the expression of IL-6,IL-8 and MCP-1 at both mRNA and protein levels in ARPE-19 cells.Curcumin suppressed PI3 K/Akt phosphorylation as well as NF-κB activation in LPSactivated ARPE-19 cells.·CONCLUSION:Curcumin plays a preventive effect on LPS-induced retinal inflammation.The beneficial effect appears associated with inhibiting of the PI3 k/Akt signaling pathway.