【摘要】 为探究miR-let-7a对LPS诱导的人系膜细胞(human mesangial cell, HMC)增殖和炎症反应的影响及其通过调节PI3K/Akt信号通路发挥作用的机制，体外条件下用0.1μg/mL LPS处理HMC, CCK-8法检测各时间点细胞活性；Western blotting检测HMC增殖细胞核抗原(proliferating cell nuclear antigen, PCNA)、凋亡相关蛋白BAX及信号通路蛋白PI3K、p-Akt的表达情况；qPCR检测细胞中miR-let-7a及炎性因子TNF-α、IL-1β、IL-6和Ⅳ型胶原蛋白mRNA的表达。转染miR-let-7a mimic或inhibitor改变HMC中miR-let-7a的表达，或使用抑制剂LY294002阻断HMC中PI3K/Akt信号通路，观察不同处理对HMC增殖、炎症反应及PI3K/Akt信号通路激活的影响。结果显示，LPS处理可诱导HMC增殖和炎症反应，抑制miR-let-7a的表达(均P<0.05)并激活PI3K/Akt信号通路(均P<0.01);与LPS组相比，过表达miR-let-7a可下调LPS诱导的HMC增殖和炎症反应，抑制PI3K/Akt信号通路的激活(均P<0.05);反之，下调miR-let-7a水平可促进由LPS刺激引起的细胞增殖、炎症反应及PI3K/Akt信号通路激活(均P<0.05);阻断PI3K/Akt信号通路也可抑制HMC的活性和炎性因子产生(均P<0.05)。综上，在经LPS处理的HMC中，miR-let-7a可通过调节PI3K/Akt信号通路抑制HMC的增殖与炎症反应。更多还原

【Abstract】 The purpose of this study was to investigate the effect of miR-let-7a on the proliferation and inflammatory response of human mesangial cell(HMC) induced by LPS and the mechanism by which miR-let-7a acts in regulating PI3K/Akt signaling pathway. To this end, HMCs were treated with 0.1 μg/mL LPS in vitro. The cell viability was measured by CCK-8 assay; the expressions of proliferating cell nuclear antigen(PCNA), apoptosis-related protein BAX, and signaling pathway proteins PI3K and p-Akt were detected by Western blotting; the mRNA levels of miR-let-7a and inflammatory factors TNF-α,IL-1β, IL-6 and collagen Ⅳ in HMC were measured by qPCR. The expression of miR-let-7a in HMC was motified by transfecting either miR-let-7a mimic or inhibitor and the PI3K/Akt signaling pathway was blocked by using the inhibitor LY294002. The effects of the above treatments on HMC proliferation, inflammatory response, and the activation of PI3K/Akt signaling pathway were examined. The results showed that LPS stimulation induced the proliferation and inflammatory response of HMC, inhibited the expression of miR-let-7a(all P<0.05), and activated the PI3K/Akt signaling pathway(all P<0.01). Compared to LPS-treated group, over-expression of miR-let-7a down-regulated LPS-induced HMC proliferation and inflammatory response and inhibited the activation of the PI3K/Akt signaling pathway(all P<0.05). On the other hand, down-regulation of miR-let-7a promoted cell proliferation, inflammatory response, and PI3K/Akt signaling pathway activation induced by LPS stimulation(all P<0.05). Blocking the PI3K/Akt signaling pathway also inhibited HMC viability and the production of inflammatory factors(all P<0.05). In conclusion, in LPS-stimulated HMC, miR-let-7a inhibits the proliferation and inflammatory response of HMC by regulating the PI3K/Akt signaling pathway.更多还原