为探讨鸡源cathelicidin-2(CATH-2)抑制金黄色葡萄球菌(Staphylococcus aureus,S.aureus)诱导IL-1β成熟与分泌的机制,采用S.aureus体外感染野生型(WT)小鼠腹腔巨噬细胞的模型,CATH-2预处理巨噬细胞2 h后感染S.aureus,通过 ELISA、Real-time PCR 和 Western blot 研究 CATH-2 对 S.aureus 诱导 IL-1β 分泌的影响.ELISA 结果显示,CATH-2显著降低了 S.aureus诱导的IL-1β、IL-6、IL-1α和IL-12表达水平(P＜0.05).RT-PCR结果显示,CATH-2显著降低了巨噬细胞中S.aureus诱导的IL-1β mRNA表达水平(P＜0.05);Western blot结果显示,CATH-2显著降低了巨噬细胞中S.aureus诱导的pro-IL-1β、IL-1β和pro-caspase-1表达水平(P＜0.05).进一步的研究结果显示,CATH-2显著降低了巨噬细胞中S.aureus诱导的NF-κB(p65)和MAPK(JNK1/2)的总蛋白和磷酸化蛋白的表达(P＜0.05).这些结果表明CATH-2通过抑制NF-κB和MAPK信号通路活性抑制炎症小体激活,进而抑制IL-1β分泌.
Mechanism study on inhibition of Staphylococcus aureus-induced IL-1β secretion by cathelicidins-2
To explore the mechanism of chicken cathelicidins-2(CATH-2)inhibiting Staphylococ-cus aureus(S.aureus)-induced IL-1β maturation and secretion,primary peritoneal macrophages of mice infected with S.aureus were pretreated with CATH-2 for 2 h and then infected with S.aureus to investigate the effect of CATH-2 on S.aureus-induced IL-1β secretion through assays of ELISA,RT-PCR and Western blot.The results of ELISA showed that CATH-2 significantly re-duced S.aureus-induced inflammatory cytokines including IL-1β,IL-6,IL-1α and IL-12(P＜0.05).The results of RT-PCR showed that CATH-2 significantly downregulated S.aureus-induced IL-1βmRNA expression(P＜0.05).The results of Western blot showed that CATH-2 remarkably de-creased S.aureus-induced protein expression of pro-IL-1 β,IL-1β and pro-caspase-1.Further findings showed that CATH-2 significantly reduced S.aureus-induced expression of total and phosphoryla-ted proteins of NF-κB(p65)and MAPK(JNK1/2)in macrophages(P＜0.05).These results dem-onstrate that CATH-2 inhibits inflammasome activation through the inhibition of NF-κB and MAPK signaling pathways,which results in the inhibition of IL-1β secretion
cathelicidins-2NLRP3inflammatory cytokinesNF-κB/MAPK signal pathway
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