膜联蛋白A1拟肽AC2-26调控ERK/NF-κB信号通路改善体外循环血清诱导大鼠肺泡Ⅱ型上皮细胞损伤

AC2-26 alleviates cardiopulmonary bypass serum-induced injury via ERK/NF-κB pathway in rat alveolar typeⅡepithelial cells

目的探究AC2-26对体外循环(CPB)血清诱导的大鼠肺泡Ⅱ型上皮细胞损伤的影响及其作用机制。方法收集16例风湿性心脏病手术患者CPB停机后的无菌血液并分离血清,建立体外循环血清诱导大鼠肺泡Ⅱ型上皮细胞损伤模型。提取健康SD大鼠原代肺泡Ⅱ型上皮细胞,培养72 h后,随机分为5组即对照组(C组),肺泡Ⅱ型上皮细胞(AECⅡ)损伤组(M组),AC2-26+AECⅡ损伤组(A组),AECⅡ损伤+Boc2组(B组),AC2-26+AECⅡ损伤+Boc2组(A+B组)。CCK-8、流式细胞术检测各组细胞增殖、凋亡情况;免疫荧光检测各组肺泡Ⅱ型上皮细胞甲酰肽受体2(FPR2)和肺泡表明活性物质(SPC)表达情况;透射电镜观察肺泡Ⅱ型上皮细胞板层小体的影响;Western blot检测各组肺泡Ⅱ型上皮细胞ERK、NF-κB表达情况。结果应用AC2-26后,CPB血清诱导的肺泡Ⅱ型上皮细胞增殖率明显升高,凋亡率明显降低(P<0.05),AC2-26明显抑制ERK及NF-κB蛋白的磷酸化(P<0.05),促进SPC的表达,改善细胞内板层小体结构及形态,这一现象可被甲酰肽受体抑制剂Boc2阻断。结论AC2-26可以减轻CPB血清诱导肺泡Ⅱ型上皮细胞损伤,其作用机制可能与FPR2调节ERK、NF-κB信号通路有关。

Objective To investigate the effect and mechanism of membrane associated protein A1 peptide AC2-26 on serum induced alveolar typeⅡepithelial cell injury in rats during cardiopulmonary bypass(CPB).Methods Sixteenpatients undergoing rheumatic heart disease surgery were included,and sterile blood was collected and serum was separated after CPB shutdown.Primary alveolar typeⅡepithelial cells were extractedfrom healthy rats,cultured for 72 h,and then randomly divided into five groups:control group(groupC),alveolar typeⅡepithelial cell(AECⅡ)injury group(groupM),AC2-26+AECⅡinjury group(groupA),AECⅡinjury+Boc2 group(groupB),and AC2-26+AECⅡinjury+Boc2 group(groupA+B).CCK-8and flow cytometry was used to detect the proliferation and apoptosis of cells in each group;Immunofluorescence was used to detect formyl peptide receptor 2(FPR2)and pulmonary surfactant(SPC)expression in typeⅡalveolar epithelial cells of each group;The alveolar typeⅡepithelial cell lamellar bodies were observed using transmission electron microscopy;Western blot was used to detect the expression of ERK and NF-κB in alveolar typeⅡepithelial cells of each group.Results After the application of AC2-26,the proliferation rate of alveolar typeⅡepithelial cells induced by CPB serum significantly increased,and the apoptosis rate significantly decreased(P<0.05).AC2-26 significantly inhibited the phosphorylation of ERK and NF-κB proteins(P<0.05),promoted the expression of SPC,and improved the structure and morphology of intracellular lamellar bodies.This phenomenon can be blocked by the formyl peptide receptor inhibitor Boc2.Conclusion AC2-26 can alleviate CPB serum induced damage to alveolar typeⅡepithelial cells,and its mechanism of action may be related to FPR2 regulating the ERK and NF-κB signaling pathways.