甲氨蝶呤通过内质网应激途径预防膝关节粘连

Methotrexate prevents knee intraarticular adhesion via endoplasmic reticulum stress signaling pathway

背景:目前膝关节瘢痕粘连的病理学机制尚不明确,多数学者认为成纤维细胞过度增殖是膝关节瘢痕粘连的主要原因。目的:观察甲氨蝶呤通过内质网应激诱导成纤维细胞凋亡及其预防膝关节粘连的作用。方法:(1)体外培养成纤维细胞,以10-5-10-9mol/L的甲氨蝶呤处理,加入PBS作为空白对照,24 h后检测成纤维细胞的活力变化,Hoechst33342染色观察甲氨蝶呤处理对成纤维细胞凋亡的影响。Western-blot检测内质网应激和凋亡相关蛋白cleaved PARP,CHOP,Bcl-2,Bax表达情况。(2)制备膝关节粘连模型,18只健康雄性新西兰大白兔随机分为3组,局部应用不同质量浓度的甲氨蝶呤,分别为2 g/L组、1 g/L组和生理盐水对照组,观察其预防膝关节粘连的效果和瘢痕组织中CHOP的表达情况。结果与结论:(1)甲氨蝶呤能有效抑制成纤维细胞的增殖和活力,呈现出明显的浓度依赖的趋势;(2)Hoechst染色发现甲氨蝶呤处理组的凋亡细胞明显多于对照组;(3)Western-blot检测显示甲氨蝶呤处理后的成纤维细胞随着时间延长,cleaved-PARP表达及CHOP、bax的表达量升高,bcl-2的表达量降低。(4)动物实验结果显示甲氨蝶呤能有效预防兔膝关节瘢痕粘连,2 g/L组的效果优于1 g/L甲氨蝶呤组,甲氨蝶呤处理组的瘢痕中CHOP的表达量明显高于对照组,而2 g/L甲氨蝶呤组的CHOP表达量也高于1 g/L甲氨蝶呤组。(5)结果说明,甲氨蝶呤能通过内质网应激诱导成纤维细胞凋亡,预防兔膝关节瘢痕粘连。

BACKGROUND：The pathogenesis of knee intraarticular adhesion is yet unknown.Excessive proliferation of fibroblasts is considered to cause knee intraarticular adhesion.OBJECTIVE：To study the preventive effects of methotrexate on knee intraarticular adhesion through fibroblast apoptosis induced by endoplasmic reticulum stress.METHODS：The viability of the cultured fibroblasts treated with methotrexate（10-5-10-9mol/L） or PBS was determined after 24 hours.Fibroblast apoptosis was detected by Hoechst33342 staining.Endoplasmic reticulum stress-and apoptosis-related proteins,including cleaved-PARP,CHOP,Bax and Bcl-2,were determined by western blot assay.Eighteen healthy male New Zealand white rabbits were used to establish the knee intraarticular adhesion models,and equally randomized into three groups,and received topical application of 2 or 1 g/L methotrexate,or normal saline（control）.The preventive effects of methotrexate on knee intraarticular adhesion and CHOP expression in scar tissue were observed.RESULTS AND CONCLUSION：Methotrexate inhibited the proliferation and viability of fibroblasts in a dose-dependent manner.The number of apoptotic fibroblasts was significantly increased compared with control group.Protein expression of cleaved-PARP,CHOP,and bax was increased,while protein expression of bcl-2 was decreased with time.The animal experiment showed that preventive effects of 2 g/L methotrexate on knee intraarticular adhesion were superior to 1 g/L methotrexate treatment.CHOP expression in the scar tissue in the methotrexate groups was higher than the control group and that was higher in high-dose methotrexate group.Our results suggest that methotrexate prevents knee intraarticular adhesion via endoplasmic reticulum stress-induced fibroblast apoptosis.