上调IL-37a表达对急性呼吸窘迫综合征大鼠肺功能及Th1/Th2平衡的影响

Effects of IL-37a expression up-regulation on lung function and Th1/Th2 balance in rats with acute respiratory distress syndrome

目的探究上调白细胞介素-37a(IL-37a)表达对急性呼吸窘迫综合征(ARDS)大鼠肺功能及Th1/Th2平衡的影响。方法构建过表达IL-37a的间充质干细胞(MSC),并与单个核细胞共培养,流式细胞术检测过表达IL-37a对Th1、Th2表达影响,ELISA检测培养基上清液IFN-γ、IL-4水平。取30只SD大鼠随机分为Control组(假手术)、ARDS组(脂多糖诱导建立ARDS模型)、IL-37a组(建模+尾静脉注射10μg/kg IL-37a重组蛋白)各10只,建模12 h后,血气分析仪检测大鼠动脉氧分压(PaO2)、氧合指数(PaO2/FiO2),并测定肺干/湿(W/D)比,HE染色观察肺组织病理并评估肺部病理损伤评分,ELISA检测肺泡灌洗液(BALF)及血清中IL-4、IFN-γ表达,流式细胞术检测脾脏Th1/Th2,Westernblot检测肺组织NF-κB、NLRP3蛋白表达。结果过表达IL-37a组细胞外周Th1、Th1/Th2、IL-4表达低于阴性对照组细胞,Th2、IFN-γ表达高于阴性对照组细胞(P<0.05);与Control组比较,ARDS组和IL-37a组PaO2、PaO2/FiO2、BALF及血清IL-4表达降低,W/D、肺部病理损伤评分、BALF及血清IFN-γ、脾脏Th1/Th2、肺组织NF-κB、NLRP3蛋白表达升高;与ARDS组比较,IL-37a组PaO2、PaO2/FiO2、BALF及血清IL-4表达升高,W/D、肺部病理损伤评分、BALF及血清IFN-γ、脾脏Th1/Th2、肺组织NF-κB、NLRP3蛋白表达降低(P<0.05)。结论上调IL-37a表达可改善ARDS大鼠肺部损伤,这可能与IL-37a能影响MSC免疫调节功能,促进Th1/Th2恢复平衡有关。

This study was designed to explore the effect of up-regulation of interleukin(IL)-37a expression on lung function and T helper type 1(Th1)/Th2 cytokine balance in rats with acute respiratory distress syndrome(ARDS).Mesenchymal stem cells(MSCs)overexpressing IL-37a were constructed and co-cultured with mononuclear cells,then flow cytometry was used to detect the effect of IL-37a overexpression on Th1 and Th2 expression,and ELISA was used to detect IFN-γand IL-4 levels in supernatant of the culture medium.Total of 30 SD rats were recruited and randomly divided into control group(sham surgery),ARDS group(lipopolysaccharideinduced establishment of ARDS model),and IL-37a group(ARDS model+tail vein injection of 10μg/kg IL-37a),with 10 rats in each group.After 12 hours of modeling,arterial oxygen pressure(PaO2)and oxygenation index(PaO2/FiO2)were measured using a blood gas analyzer,and the dry/wet(W/D)ratio of the lungs was measured.HE staining was used to observe lung tissue pathology and evaluate lung pathological injury scores;ELISA was used to detect alveolar lavage fluid(BALF)and serum IL-4 and IFN-γexpression;flow cytometry was used to detect spleen Th1/Th2;while Western blot was used to detect the protein expression of NF-κB and NLRP3 in lung tissue.Data showed that the levels of Th1,Th1/Th2,and IL-4 in the peripheral cells of the overexpression IL-37a group were lower than those in the negative control group cells,while the expression of Th2 and IFN-γwere higher than those in the negative control group cells(P<0.05).Compared with the control group,the ARDS group showed lower levels of PaO2,PaO2/FiO2,BALF and serum IL-4,but higher levels of W/D,lung pathological injury score,BALF and serum IFN-γ,spleen Th1/Th2,and lung tissue NF-κB and NLRP3 proteins.IL-37a could reverse the changes mentioned above in ARDS rats(P<0.05).Taken together,up-regulation of IL-37a expression can ameliorate lung injury in ARDS rats,which may be related to the role of IL-37a in inducing MSC differentiation and promoting the restoration of Th1/Th2 balance.