川芎嗪干预早期膝骨关节炎大鼠软骨Ⅱ型胶原纤维α1基因与血管内皮生长因子mRNA及miR20b的表达

Ligustrazine for early-stage knee osteoarthritis in rats: changes in the expression levels of type II collagen fiber alpha 1, vascular endothelial growth factor and miR20b in the cartilage

背景:课题组前期研究发现川芎嗪能明显降低骨关节炎关节液中NO、前列腺素E2水平,对减轻骨性关节炎的炎症有一定作用,但具体机制还不清楚。目的:观察川芎嗪治疗膝骨关节炎模型关节软骨中Ⅱ型胶原纤维α1基因、血管内皮生长因子mRNA及miR20b表达水平,并探讨川芎嗪治疗早期膝骨关节炎大鼠的作用机制。方法:健康雄性SD大鼠随机分为正常组、模型组、川芎嗪高剂量组、川芎嗪低剂量组、阳性对照组,后4组通过木瓜蛋白酶关节腔注射制作早期膝骨关节炎大鼠模型。造模后川芎嗪高、低剂量组分别灌胃川芎嗪100 mg/kg和50 mg/kg,阳性对照组灌服塞来昔布24 mg/kg;正常组、模型组灌服等量生理盐水。干预6周后取材,分别行鼠软骨大体组织学评分、qR T-PCR检测软骨Ⅱ型胶原纤维α1基因、血管内皮生长因子mRNA及miR20b的表达水平。结果与结论:(1)软骨Mankin评分:川芎嗪高、低剂量组和阳性对照组均较正常组高(P<0.05),较模型组低(P<0.05),且川芎嗪高剂量组<阳性对照组<川芎嗪低剂量组;(2)川芎嗪各剂量组和阳性对照组的Ⅱ型胶原纤维α1基因、血管内皮生长因子mRNA表达较正常组上调(P<0.05),较模型组下调(P<0.05),且川芎嗪高剂量组<阳性对照组<川芎嗪低剂量组;(3)川芎嗪各剂量组、阳性对照组及正常组的miR20b表达均较模型组上调(P<0.05),其中川芎嗪低剂量组<阳性对照组<川芎嗪高剂量组;(4)提示:川芎嗪对早期膝骨关节炎大鼠治疗具有积极作用,可能通过上调软骨中miR20b从而抑制血管内皮生长因子mRNA的表达,促进软骨的修复。

BACKGROUND:Preliminary studies have found that ligustrazine can effectively improve the levels of nitric oxide and prostaglandin E2,and alleviate the inflammatory response of osteoarthritis,but the related mechanism remains unclear.OBJECTIVE:To observe the effect of ligustrazine on the expression levels of type II collagen fiberα1,vascular endothelial growth factor(VEGF)mRNA and miR20b in the articular cartilage of knee osteoarthritis model,and to explore the mechanism of ligustrazine for early-stage knee osteoarthritis in rats.METHODS:Healthy male Sprague-Dawley rats were randomized into normal,model,high-and low-dose ligustrazine,and positive control groups.Rats in the latter four groups were used to establish the model of early-stage knee osteoarthritis by intra-articular injection of papain,and were then intragastrically given the administration of normal saline,100 and 50 mg/kg ligustrazine,and 24 mg/kg celecoxib,respectively.The normal group was given the same volume of normal saline.The treatment in each group lasted for 6 weeks.Then,the rat cartilage was taken,and changes of cartilage tissues were assessed by Mankin scores.Expression levels of type II collagen fiberα1,VEGF mRNA and miR20b in the cartilage were detected by qRT-PCR.RESULTS AND CONCLUSION:The order of Mankin scores was as follows:normal group<high-dose ligustrazine group<positive control group<low-dose ligustrazine group<model group(P<0.05).The mRNA expression levels of type II collagen fiberα1 and VEGF were the highest in the normal group,followed by the high-dose ligustrazine group,positive control group,low-dose ligustrazine group,and model group(P<0.05).The expression level of miR20b was significantly up-regulated except the model group,and its order was follows:high-dose ligustrazine group<positive control group<low-dose ligustrazine group.Our results indicate that ligustrazine has a positive effect on earlystage knee osteoarthritis in rats,and the possible mechanisms by which ligustrazine promotes cartilage repair are to up-regulate miR20b expression and to inhibit VEGF mRNA expression.