PI3K/AKT信号通路在大鼠腹腔感染性脓毒症急性肾损伤中的作用

目的 探究磷脂酰肌醇3-激酶/蛋白激酶B（PI3K/AKT）信号通路在大鼠腹腔感染性脓毒症急性肾损伤（acute kidney injury，AKI）中的作用。方法 使用盲肠结扎穿孔（cecal ligation and puncture，CLP）的方法制备大鼠腹腔感染性脓毒症模型，按照检测时间点（24、48、72 h）分组，于术后各时间点用全自动生化分析仪检测血清肌酐（Cr）、尿素氮（BUN）水平；用实时定量聚合酶链反应（Real-time PCR）检测大鼠肾脏组织PI3K mRNA及AKT mRNA的表达水平，采用蛋白免疫印迹法（Western blot，WB）检测大鼠肾脏组织Nod样受体蛋白3（NLRP3）、凋亡相关斑点样蛋白（ASC）、半胱氨酸天冬氨酸特异性蛋白酶1（Caspase-1）蛋白表达水平，采用酶联免疫吸附法（ELISA）检测血清肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）-1β及IL-18的表达水平。假手术组除不进行盲肠结扎及穿孔外，其余操作与CLP组相同。结果 与假手术组相比，CLP各组大鼠血Cr、BUN水平出现明显升高（P＜0.05），肾脏组织内PI3K及AKT mRNA 表达水平明显升高（P＜0.01），且其下游 NLRP3 炎性小体蛋白表达水平明显升高（P＜0.01），同时血清TNF-α、IL-1β及IL-18水平明显升高（P＜0.01）。结论 PI3K/AKT信号通路在腹腔感染性脓毒症AKI中具有重要作用，其活化诱导下游NLRP3炎性小体活化增加，进而使炎症因子释放增加并加重脓毒症病情。

The role of PI3K/AKT in acute kidney injury induced by abdominal sepsis in rats

Objective To investigate the role of PI3K/AKT in acute kidney injury (AKI) induced by abdominal sepsis in rat model. Methods The cecal ligation and puncture (CLP) was used to establish rat model of abdominal sepsis. The serum levels of creatinine (Cr) and urea nitrogen (BUN) were detected by automatic biochemical analyzer at different time points (24, 48 and 72 h) after operation. The expressions of PI3K/AKT mRNA were detected by real-time PCR. Western blot assay was used to verify the expression levels of NLRP3, ASC and Caspase-1. The serum levels of TNF-α, IL-1β and IL-18 were detected by enzyme-linked immunosorbent assay. Results The serum levels of Cr and BUN were increased significantly in CLP group compared with those of control group (P＜0.05). The expression levels of PI3K/AKT in kidney were significantly increased in rats with abdominal sepsis (P＜0.01). And the released NLRP3 inflammasome, which was activated by PI3K / AKT, was significantly increased (P＜0.01). Meanwhile, compared with the sham-operated group, the serum levels of IL-1β, TNF - α and IL-18 were increased significantly (P＜0.01). Conclusion PI3K / AKT signaling pathway plays an important role in acute kidney injury induced by abdominal sepsis, which activates the NLRP3 inflammasome, increases the release of inflammatory cytokine and aggravates the sepsis condition.