PD1经上调心脏巨噬细胞GPR37/JNK/PPAR-γ通路活性减轻大鼠心脏缺血再灌注损伤

Protectin D1 alleviates cardiac ischemia-reperfusion injury in rats by up-regulating GPR37/JNK/PPAR-γ signaling pathway in cardiac macrophages

目的探讨保护素(protectin D1, PD1)经GPR37/JNK/PPAR-γ通路减轻心脏缺血再灌注损伤的机制。方法 6~8周雄性SD大鼠60只(体质量180~220 g),于术前3日每日经腹腔注射PD1 100 nmol/L或等量生理盐水后,建立大鼠心脏缺血再灌注损伤模型,分为4组:假手术组;缺血再灌注组(IR组);IR+PD1组;IR+PD1+CB组。各组大鼠于术后6 h、24 h、48 h、14 d采集大鼠心脏标本和血液标本,并分离心脏巨噬细胞蛋白。检测心脏病理改变、心肌酶谱改变、心肌纤维化程度、血清炎症因子表达、心肌细胞吞噬功能、细胞极性改变、上清液炎症因子表达、GPR37/JNK/PPAR-γ信号通路表达。结果 PD1干预后,大鼠心脏病理改变显著下降、心肌酶谱表达下降(P<0.05),血清IL-1β(86.6±22.4)U/L、TNF-α(89.4±18.2)U/L、IL-6(76.7±15.2)U/L表达下降,IL-10(87.6±18.4)U/L、TGF-β(112.7±22.6)U/L表达升高(P<0.05);PD1处理心脏巨噬细胞后,心脏巨噬细胞对凋亡细胞吞噬增高(P<0.05),M2型极化增加(P<0.05),上清液中IL-1β(109.5±21.6) U/L、TNF-α(95.4±17.8) U/L、IL-6(134.2±27.1) U/L表达下降,IL-10(158.4±31.8)U/L、TGF-β(149.6±27.6)U/L表达升高(P<0.05),GPR37(2.14±0.31)、IRE1α(2.67±0.44)、ATF6 (1.97±0.37)、PERK (2.27±0.67)、p-JNK (1.95±0.39)、PPAR-γ(1.87±0.67)表达上升(P<0.05)。结论 PD1能够减轻心脏缺血再灌注损伤程度,其机制可能是经上调GPR37/JNK/PPAR-γ通路的活性,促进心脏巨噬细胞吞噬功能、M2型极化、抑炎因子表达。

Objective To investigate the mechanism by which protectin D1(PD1)alleviates cardiac ischemia-reperfusion(IR)injury via GPR37/JNK/PPAR-γsignaling pathway.Methods Male adult SD rats(6-8 weeks old)were randomly divided into sham-operation group,IR group,IR+PD1 group,and IR+PD1+cytochalasin B(CB)group.In the latter 3 groups,the rats were subjected to daily intraperitoneal injections of normal saline,PD1(100 nmol/L),or PD1 and CB for consecutive 3 days before establishment of cardiac IR injury models.At 6,24,and 48 h and at 2 weeks after the surgery,the hearts and blood samples were collected from each group,and the cardiac macrophages were isolated and cultured.The cardiac pathologies,changes in cardiac enzyme profile,cardiac fibrosis,serum inflammatory factors,phagocytic function of the cardiac macrophages,changes in the cell polarity,and the expressions of inflammatory factors and GPR37/JNK/PPAR-γsignaling pathway in cultured cardiac macrophages were detected.Results In the rats with cardiac IR injury,PD1 treatment significantly alleviated the cardiac pathologies,lowered the expressions of the cardiac enzymes(P<0.05),decreased the serum levels of IL-1β,TNF-α,and IL-6 while increased the serum levels of IL-10 and TGF-β(P<0.05).In the cultured cardiac macrophages,PD1 treatment significantly enhanced their phagocytosis of the apoptotic cells(P<0.05)and M2-type polarization(P<0.05),decreased the expressions of IL-1β,TNF-α,IL-6,and increased the expressions of IL-10 and TGF-β(P<0.05)and the expressions of GPR37,IRE1α,ATF6,PERK,p-JNK,and PPAR-γ(P<0.05).Conclusion PD1 can alleviate cardiac IR injury in rats possibly by up-regulating the GPR37/JNK/PPAR-γsignaling pathway to enhance the phagocytic activity of the cardiac macrophages and the expressions of the anti-inflammatory factors.