腺苷酸环化激酶雷帕霉素靶蛋白信号通路参与小鼠急性肾损伤的机制研究

Mechanism of AMPR-mTOR signaling pathway involved in acute kidney injury in mice

目的探讨腺苷酸环化激酶(AMPK)雷帕霉素靶蛋白(mTOR)信号通路参与小鼠急性肾损伤的机制。方法将健康雄性C57BL/6小鼠随机分为对照组、模型组及SB2111组,每组各10只。模型组与SB2111组小鼠采用脂多糖(LPS)建立急性肾损伤模型,对照组以等剂量的生理盐水代替。SB2111组另外给予经腹腔右侧注射2 mL AMPK阻断剂SB2111治疗。观察与记录三组小鼠的一般状况、病理特征并检测肾功能情况。结果模型组与SB2111组的体重都显著少于对照组,差异有统计学意义(P<0.05);模型组的肾脏重量大于对照组(P<0.05),而SB2111组的肾脏重量与对照组比较,差异无统计学意义(P>0.05)。模型组与SB2111组的24 h尿蛋白、血肌酐、血尿素氮均高于对照组,差异有统计学意义(P<0.05),而SB2111组的24 h尿蛋白、血肌酐、血尿素氮均低于模型组,差异有统计学意义(P<0.05)。对照组肾小管上皮细胞胞质丰富,肾组织的肾小球和肾小管结构正常;模型组肾小球充血肿胀、肾小管腔有管型形成;SB2111组部分肾小球充血,近端肾小管上皮细胞轻度肿胀,出现少量炎症细胞浸润。模型组与SB2111组的肾组织TNF-α、TGF-β1水平与AMPK、mTOR相对表达水平都显著高于对照组,而SB2111组的肾组织TNF-α、TGF-β1水平与AMPK、mTOR相对表达水平均低于模型组,差异均有统计学意义(P<0.05)。结论AMPK-mTOR信号通路在小鼠急性肾损伤中呈现激活状况,抑制AMPK-mTOR信号通路的表达能抑制TNF-α和TGF-β1的表达水平,促进小鼠肾功能的恢复。

Objective To investigate the mechanism of AMP-activated protein kinase(AMPK)-mammalian target of rapamycin(mTOR)signaling pathway involved in acute kidney injury in mice.Methods Thirty cases of healthy male C57BL/6 mice were divided into three groups-control group,model group and SB2111 group,with 10 mice in each group.Both the model group and the SB2111 group were treated with lipopolysaccharide(LPS)to establish acute kidney injury model,the control group were replaced with equal dose of normal saline,the SB2111 group were treated with 2 mL of AMPK blocker SB2111.The general condition and pathological characteristics of the mice were observed and recorded,and renal function were detected.Results The body weight of the model group and the SB2111 group were significantly lower than those of the control group(P<0.05),and the kidney of the model group were significantly higher than the control group(P<0.05)that there were no significant difference compared between the SB2111 group and the control group(P>0.05).After the experiment,the 24 h urine protein,serum creatinine and urea nitrogen in the model group and SB2111 group were higher than the control group,and the SB2111 group were lower than the model group that compared the difference were statistically significant(P<0.05).The renal tubular epithelial cells in the control group were rich in cytoplasm,the glomeruli and renal tubules in the renal tissues were normal,the glomerular congestion and tubular formation in the model group,the glomerular congestion in the SB2111 group,and the proximal koji,tubular epithelial cells were slightly swollen with small amount of inflammatory cell infiltration.The relative expression levels of TNF-α,TGF-β1,AMPK and mTOR in the model group and SB2111 group were significantly higher than those in the control group,and the SB2111 group were lower than the model group that compared the difference were statistically significant(P<0.05).Conclusions AMPK-mTOR signaling pathway are activated in acute kidney injury in mice.Inhibition of AMPK-mTOR signaling pathway can inhibit the expression of TNF-αand TGF-β1 and promote the recovery of renal function in mice.