二十二碳六烯酸对大鼠骨关节炎关节软骨组织退变的影响及机制  

Effect and mechanism of docosahexaenoic acid on cartilage degeneration in osteoarthritis rat model

作　　者：于浩淼[1] 曹瑞祺 马立峰[1] 李强[1] 郭艾[1] YU Haomiao;CAO Ruiqi;MA Lifeng;LI Qiang;GUO Ai(Department of Orthopaedics,Beijing Friendship Hospital,Capital Medical University,Beijing 100050,China)

机构地区：[1]首都医科大学附属北京友谊医院骨科,北京100050

出　　处：《中华骨与关节外科杂志》2023年第3期253-260,共8页Chinese Journal of Bone and Joint Surgery

基　　金：北京市自然科学基金面上项目(7222035)。

摘　　要：目的:研究二十二碳六烯酸(DHA)对大鼠骨关节炎(OA)关节软骨组织退变的影响,并初步探讨其机制。方法:手术切除内侧半月板、切断前交叉韧带构建大鼠OA动物模型,并采用富含DHA的饲料喂养;同时采用假手术或正常饲料喂养进行对照。HE染色、甲苯胺蓝染色、番红O-固绿染色观察关节软骨组织退变程度,采用改良Mankin评分评价番红O-固绿染色标本关节软骨组织损伤;采用免疫组织化学染色法检测关节软骨组织中Ⅱ型胶原的表达;采用蛋白印迹法检测关节软骨组织中哺乳动物雷帕霉素靶蛋白(mTOR)、基质金属蛋白酶13(MMP-13)、Beclin-1及通路蛋白磷酸化细胞外信号调节激酶(p-ERK)、磷酸化氨基末端蛋白激酶(p-JNK)、磷酸化p38蛋白(p-p38)的表达;microCT观察软骨下骨的结构变化。结果:口服DHA减轻OA大鼠关节软骨退变程度,并显著降低Mankin评分;免疫组织化学染色结果显示DHA可提高软骨细胞Ⅱ型胶原阳性表达率;蛋白印迹法检测结果显示DHA可减少关节软骨组织中mTOR和MMP-13的表达,并增加Beclin-1的表达;microCT显示DHA可改善骨小梁微细结构,减少软骨下骨囊变及硬化;通路蛋白检测显示DHA可显著抑制p-p38的表达。结论:DHA可有效减轻OA大鼠关节软骨退变及损伤,并改善软骨下骨微细结构。这一作用通过增加软骨细胞Ⅱ型胶原和Beclin-1的表达,并降低mTOR和MMP-13的表达而实现。DHA的作用机制为抑制p38通路。Objective:To investigate the effect of docosahexaenoic acid(DHA)on cartilage degeneration in an osteoarthritis(OA)rat model,and to preliminarily explore its mechanism.Methods:Rat knee OA model was established by anterior cruciate ligament transection and medial meniscectomy and was fed with DHA-rich diets.The rats with sham operation or normal diets were used as controls.The cartilage degeneration was observed by hematoxylin and eosin staining,toluidine blue staining,and safranin-O fast green staining.The cartilage damage of the fast green stained specimens was evaluated using a modified Mankin score.The expression of typeⅡcollagen in the cartilage was detected by immunohistochemistry.The expression of mammalian target of rapamycin(mTOR),matrix metalloproteinase 13(MMP-13),Beclin-1,phosphorylated extracellular signal-regulated kinase(p-ERK),phosphorylated c-Jun N-terminal kinase(p-JNK),and phosphorylated P38 protein(p-p38)were measured by Western-blot.The structural changes of subchondral bone were observed by microCT.Results:Oral administration of DHA reduced the degree of articular cartilage degeneration and significantly decreased the Mankin score in OA rats.Immunohistochemical results showed that DHA increased the positive rate of typeⅡcollagen expression in chondrocytes.Western-blot showed that DHA reduced mTOR and MMP-13 expression and increased Beclin-1 expression in cartilage tissues.MicroCT showed that DHA improved the microstructure of bone trabeculae and reduced subchondral bone cyst and sclerosis.The pathway protein analysis showed that DHA significantly inhibited the expression of p-p38.Conclusions:DHA can effectively alleviate articular cartilage degeneration and damage and improve subchondral bone microstructure in OA rats,which was achieved by increasing typeⅡcollagen and Beclin-1 expression and decreasing mTOR and MMP-13 expression in the cartilage.The inhibition of p38 pathway may play an important role in this procedure.

关 键 词：骨关节炎 二十二碳六烯酸 软骨细胞 Ⅱ型胶原 P38通路 

分 类 号：R684.3[医药卫生—骨科学]