骨关节炎骨赘发生过程中的分子表达特征

The characterization of molecule expressions in the development of osteophytes in osteoarthritis

目的探讨Ⅰ型、Ⅱa型、Ⅱb型、Ⅹ型胶原以及氨基多糖等分子在骨关节炎骨赘发生过程中的表达特点。方法取全膝关节置换术中取下的原发性骨关节炎骨赘标本25例,男6例,女19例;平均年龄69.1岁。固定脱钙后制成石蜡切片,行HE和甲苯胺蓝染色了解基质含量、细胞数量和蛋白多糖的表达。采用S-P法进行Ⅰ型、Ⅱ型（Ⅱa和Ⅱb）、Ⅹ型胶原分子的免疫组化染色。结果根据骨赘中主要组织的细胞形态学和Ⅰ型、Ⅱa型、Ⅱb型、Ⅹ型胶原以及氨基多糖分子的表达特点,共获得五种主要不同类型的骨赘组织。Ⅰ型组织主要含有间充质细胞表达的Ⅰ型胶原;Ⅱ型组织内出现了前软骨细胞分化,并表达Ⅱa型胶原和蛋白多糖;Ⅲ型组织表达Ⅱb型胶原及多量蛋白多糖,同时也表达Ⅰ型和Ⅱa型胶原;Ⅳ型组织的软骨细胞呈明显的带状分布,表达丰富的Ⅱb型胶原和蛋白多糖,深层的肥大软骨细胞表达Ⅹ型胶原;Ⅴ型组织的成分与正常关节软骨接近,主要表达Ⅱb型胶原及丰富的氨基多糖分子。这五种组织可能分别代表骨赘发生过程中的间充质细胞期、前软骨细胞期、软骨细胞期、早期骨赘期和成熟骨赘期。结论在骨关节炎骨赘发生的不同阶段,Ⅰ型、Ⅱa型、Ⅱb型、Ⅹ型胶原分子以及氨基多糖分子存在特异的分化表达,据此可将骨赘的发生过程分期进行研究。

Objective To investigate the characteristics of expressions of collagen Ⅰ, Ⅱ a, Ⅱ b, Ⅹ and glycosaminoglycans in the development of osteophytes in osteoarthritis. Methods 25 specimens were obtained from individuals undergoing total knee arthroplasty due to severe primary osteoarthritis. There were 19 females and 6 males with an average age of 69.1 years. Tissue samples were fixed and decalcified before embedded in paraffin wax and made into sections. HE and toluidine blue stainings were performed to evaluate matrix abundance, cellularity, and the content of glycosaminoglycans. The expressions of collagen Ⅰ , Ⅱ a, Ⅱ b, and Ⅹ were detected by immunohistochemistry using streptavidin-biotin-complex technique. Results Based on histomorphology and the expressions of above different collagens and glycosaminoglycans, five different types of osteophytic tissues were identified. Type Ⅰ tissue mainly consists of mesenchymal fibroblast- like cells producing collagen Ⅰ . Type Ⅱ tissue was characterized by the onset of collagen Ⅱ a and glycosaminoglycans expressed by prechondrocyte, whereas type Ⅲ tissue was marked by the coexpression of collagen Ⅱ b, glycosaminoglycans, and collagen Ⅱ a on the one hand and collagen Ⅰ on the other hand. Type Ⅳ tissue showed a clear zonal organization of chondrocytes. The expression of collagen Ⅱb and glycosaminoglycans was abundant with deepest hypertrophic chondrocytes expressing collagen Ⅹ. Type Ⅴ tissue had a composition similar to normal articular hyaline cartilage with a predominance of collagen Ⅱb and abundant glycosaminoglycans. These five types probably indicated the different stages of osteophytes development, including mesenchymal cell, prechondrocyte, chondrocyte, early osteophyte and mature osteophyte. Conclusion During the different stages of osteophyte development, there were specific differential expressions of collagen Ⅰ , Ⅱ a, Ⅱ b, Ⅹ and glycosaminoglycans. On this basis, the development of osteophyte could be staged for further understanding.