大鼠DDH关节软骨早期退变和X型胶原、基质金属蛋白酶13表达相关性的研究

摘要

Objective To detect the changes of expressions of X type collagen and matrix metalloproteinases-13 (MMP-13)of acetabular cartilage in the different stages of developmental dysplasia of the hip(DDH)and to inves-tigate the relevance between type X collagen,MMP-13 and the retrogression mechanism of acetabular cartilage. Methods 80 neonatal Wistar rats were randomly divided into DDH group(n = 40)and control group(n = 40). The DDH model was induced by fixation on both hips and knees for ten days and continued to be raised after relie-ving fixation. Those rats were sacrificed at age of 2,4,6,8 weeks respectively. The hips were isolated from the DDH model rats and an untreated control group for gross morphometry. Meanwhile,collagen X and matrix metallo-proteinase 13(MMP-13)were detected by quantitative RT-PCR and immunofluorescence. Results Necropsy spec-imens of DDH model rats showed thickening of the capsule. The acetabular surface was irregularly flat and had lost its smoothness. Flat and underdeveloped femoral head were observed as well. We also found the acetabulum and femoral head became smaller with poorer containment particularly after 4 weeks of age. Collagen X and MMP-13 ex-pressions were higher in the superficial zone of hip cartilage of DDH rats than in that of controls(P < 0. 05),and the increase was age-dependent. mRNA expression of Collagen X and MMP-13 showed similar results(P < 0. 05). Conclusion This study shows that degenerative cartilage changes occur at an early stage in the rats of the DDH model and become aggravated with age,which are closely associated with collagen X and MMP-13.%目的：检测 X 型胶原、基质金属蛋白酶13（MMP-13）在发育性髋关节发育不良（DDH）大鼠模型不同时期关节软骨中表达的改变情况，探讨 X 型胶原、MMP-13与软骨早期退变的相关性。方法选取新生 Wistar 大鼠80只，随机均等分成 DDH 组和对照组。DDH 组新生大鼠后肢襁褓位固定10 d 后解除固定继续饲养，分别于鼠的2、4、6、8周龄处死，离断髋关节，观察髋关节软骨的大体形态。用免疫组化和 qRT-PCR 法检测 X 型胶原、MMP-13的表达。结果 DDH模型鼠的尸体解剖样本显示关节囊增厚，髋臼表面呈不规则、不平整，股骨头扁平且发育较小，头臼包容差，尤其4周后更明显；与对照组相比，在髋关节软骨浅表区域有较高的X 型胶原和 MMP-13表达（P <0.05），并且这种增长是随着年龄增长而增长的，X 型胶原和 MMP-13的 mRNA 表达显示出相似的结果（P <0.05）。结论 DDH 模型鼠在较早阶段出现软骨退化，随着年龄逐渐加重；X 型胶原和 MMP-13表达与 DDH 软骨早期退变有密切的关系。