桔梗总皂苷治疗大鼠佐剂性关节炎的作用及其对GRP78/XBP1/CHOP信号通路的影响

Therapeutic potential of Platcodon grandiflorum total saponins and its effect on GRP78/XBP1/CHOP singal pathway in adjuvant-induced arthritis rats

目的探讨桔梗总皂苷(CKS)对佐剂性关节炎(AA)大鼠的作用及部分机制研究。方法 60只SD大鼠随机分为6组,每组10只,分别为正常组、模型组、CKS低、中、高剂量组(50、100、200 mg/kg)及阳性药来氟米特组(2 mg/kg)。采用弗氏完全佐剂注射左后足趾皮内建立AA大鼠模型,观察各组大鼠足肿胀度、多发性关节炎指数并进行组织病理学检查;ELISA试剂盒检测血清中肿瘤坏死因子-α(TNF-α)和白介素1β(IL-1β)的水平;Real-time PCR和Western blot法检测各组大鼠滑膜组织中葡萄糖调节蛋白78(GRP78)、X盒结合蛋白1(XBP1)、CCAAT增强子结合蛋白同源蛋白(CHOP)、TNF-αm RNA和蛋白表达的情况。结果 CKS(100、200 mg/kg)可显著抑制大鼠继发性足肿胀并减轻其膝关节的病理变化;可将大鼠血清中TNF-α和IL-1β的水平明显降低(P<0.05);同时可以下调GRP78、XBP1、CHOP、TNF-αm RNA和蛋白的表达(P<0.05)。结论 CKS对AA大鼠具有一定的治疗作用,其机制可能是与抑制内质网应激GRP78/XBP1/CHOP信号通路,从而抑制滑膜细胞分泌和表达的TNF-α有关。

Objective To explore the effect of Platcodon grandiflorum total saponins （CKS） in adjuvant-induced arthritis （AA） rats and its possible mechanisms. Methods Sixty SD rats were randomly divided into six groups： normal group, model group, CKS（50 mg/kg）, CKS（100 mg/kg）, CKS（200 mg/kg） group and leflunomide （2 mg/kg） group. AA animal model was induced by complete Freund＇ s adjuvant toothed, then the paw swelling, pol- yarthritis index and histopathological changes were observed. Tumor necrosis factor-α（TNF-α） and interleukin 1 β （IL-1 β） from blood serum were detected by ELISA. The mRNA and protein expressions of 78-KD glucose regula- ted protein （ GRP78 ）, X-box binding protein 1 （ XBP1 ）, CCAAT/enhancer binding protein homologous （CHOP） and TNF-α were evaluated by real-time PCR and Western blot assay. Results In vivo, our data showed that CKS （100,200 mg/kg） could obviously suppress the secondary paw swelling, improve the morphologic changes of artic- ular cartilages and synovium, and decrease TNF-α and IL-1 β serum levels （P 〈 0. 05）. The real-time PCR and Western blot resuhs displayed that CKS could significantly inhibit GRP78, XBP1, CHOP and TNF-α expressions in AA group （P 〈 0. 05 ）. Conclusion This study indicates that CKS could improve the adjuvant-induced arthritis in a dose-dependent manner. The inhibition of GRP78/XBP1/CHOP/TNF-α signaling pathways is involved in CKS- mediated modulation of inflammation.