冷诱导RNA结合蛋白在体外循环期间导致急性肾损伤机制实验研究

Mechanisms of cold-induced RNA-binding protein leading to acute kidney injury during cardiopulmonary bypass

目的:探讨在体外循环(CPB)期间细胞外冷诱导RNA结合蛋白(CIRP)对急性肾损伤(AKI)的影响,并探索其作用机制。方法:H9c2细胞在常温常氧(NN)、低温缺氧(HH)、HH后复温复氧(HHNN)和HHNN中加入CIRP抑制剂(C23)四种条件下培养。NRK-52E细胞进一步与H9c2细胞的培养基共同培养。通过ELISA评估CIRP、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)水平的表达。TUNEL染色检测NRK-52E细胞凋亡情况。结果:低温缺氧可诱导H9c2细胞分泌CIRP,并通过TLR-4/MyD88通路促进IL-6和TNF-α的表达。高表达的CIRP和其他炎症因子可诱导NRK-52E细胞凋亡。而且C23可以阻断CIRP介导的促炎反应和对NRK-52E细胞的损伤作用。结论:低温缺氧条件下心肌细胞释放大量CIRP,并激活炎性反应,通过TLR-4/MyD88通路释放TNF-α和IL-6,诱导肾小管上皮细胞凋亡。

Objective:To investigate the effect of extracellular cold-inducible RNA-binding protein(CIRP)on acute kidney injury(AKI)during cardiopulmonary bypass(CPB)and explore its mechanism of action.Methods:H9c2 cells were cultured in four conditions:normal temperature and normoxia(NN),hypothermia and hypoxia(HH),rewarming and reoxygenation after HH(HHNN)and adding CIRP inhibitor in HHNN(C23).NRK-52E cells were further incubated with the medium of H9c2 cells.The expression of CIRP,interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)levels were assessed by ELISA.The apoptosis of NRK-52E cells was detected by TUNEL staining.Results:Hypothermia and hypoxia could induce H9c2 cells to secrete CIRP,and promote the expression of IL-6 and TNF-αthrough the TLR-4/MyD88 pathway.High expression of CIRP and other inflammatory factors can induce apoptosis of NRK-52E cells.Moreover,C23 could block CIRP-mediated pro-inflammatory and damage to NRK-52E cells.Conclusion:Cardiomyocytes release a large amount of CIRP and activate inflammatory reaction under hypothermia and hypoxia.TNF-αand IL-6 are released through TLR-4/MyD88 pathway to induce apoptosis of renal tubular epithelial cells.