摘要
目的:探讨基质金属蛋白酶7(MMP7)在小鼠脓毒症相关急性肾损伤模型中的表达及作用。方法:通过盲肠结扎穿孔(CLP)手术在具有C57BL/6J遗传背景的MMP7敲除(MMP7-KO)小鼠和野生型(WT)C57BL/6J小鼠中诱导脓毒症。采用外源性MMP7重组蛋白对MMP7-KO小鼠进行预处理。通过脂多糖(LPS)刺激正常人近端肾小管上皮细胞系HKC-8建立体外模型。采用Western blot检测MMP7和哺乳动物雷帕霉素靶蛋白复合体1(mTORC1)表达。HE和TUNEL染色评估小鼠的肾损伤。Hoechst 33342染色评估细胞凋亡。结果:与假手术组相比,CLP组在CLP后6 h肾脏组织中MMP7蛋白表达降低,这种降低趋势持续到48 h。MMP7-KO的CLP组小鼠肾小管损伤病理评分和TUNEL阳性肾小管细胞显著高于WT的CLP组(P<0.01)。MMP7重组蛋白孵育可很大程度上降低LPS诱导的HKC-8细胞凋亡。LPS诱导了HKC-8细胞的mTORC1表达,而MMP7可以抑制mTORC1表达。MMP7能够明显促进mTORC1降解,产生分子量为18 kD的较小片段。此外,MMP抑制剂II(一种MMP7选择性抑制剂)抑制了MMP7介导的mTORC1降解。接受外源性MMP7的MMP7-KO小鼠CLP后24 h的肾小管损伤病理评分、TUNEL阳性肾小管细胞和mTORC1蛋白表达均较载体对照组显著降低(P<0.01)。结论:脓毒症时,小鼠肾脏MMP7的表达降低。外源性MMP7可通过降解mTORC1减轻肾小管上皮细胞凋亡,从而具有肾脏保护作用。
AIM:To investigate the effect of matrix metalloproteinase 7(MMP7)on mouse acute kidney injury induced by sepsis.METHODS:Sepsis was induced by cecal ligation and perforation(CLP)surgery in both MMP7knockout(MMP7-KO)mice and wild-type(WT)C57BL/6J mice.An in vitro model was achieved by stimulating human proximal tubular epithelial cell line HKC-8 with lipopolysaccharide(LPS).Western blot was used to detect the expression of MMP7 and mammalian target of rapamycin complex 1(mTORC1).HE and TUNEL staining were performed to assess renal injury in mice.Hoechst 33342 staining was performed to assess apoptosis.RESULTS:Compared with sham group,the renal expression of MMP7 in CLP group decreased as early as 6 h and lasted for up to 48 h.The pathological scores of CLP-induced renal tubular injury and TUNEL-positive tubular cells in MMP7-KO CLP group were significantly higher than those in WT CLP group(P<0.01).Incubation with MMP7 recombinant protein largely protected HKC-8 cells from LPS-induced apoptosis.LPS induced but MMP7 inhibited mTORC1 expression.MMP7 cleaved mTORC1,yielding a fragment with a molecular weight of 18 kD.MMP inhibitor II prevented MMP7-mediated degradation of mTORC1.Exogenous MMP7 improved the tubular injury pathological scores,and decreased TUNEL-positive tubular cells and mTORC1 expression in MMP7-KO mice treated with CLP(P<0.01).CONCLUSION:Sepsis reduces MMP7 expression in mouse kidney.Exogenous MMP7 alleviates acute kidney injury induced by sepsis via degradation of mTORC1.
作者
丁璐
柳红英
王卉
范桄溥
DING Lu;LIU Hong-ying;WANG Hui;FAN Guang-pu(Department of Critical Care Medicine,Peking University People's Hospital,Beijing 100044,China;Department of Cardiology,Peking University People's Hospital,Beijing 100044,China)
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
2022年第12期2229-2235,共7页
Chinese Journal of Pathophysiology
基金
北京市卫生健康科研基金项目(No.20210069)。
