体外培养髁突软骨细胞表型特征的研究

目的：研究体外培养的髁突软骨细胞（mandibular condylar chondrocyte,MCC)表型变化的特征。方法：消化法培养2周新西兰白兔的MCC,采用相差显微镜观察、图象分析、MTT、免疫组化等方法对不同代数的MCC进行细胞形态和大小、生长曲线以及Ⅰ、Ⅱ型胶原的表达等方面的比较。结果：培养早期（1－3代）MCC以多角形为主,5－6代后梭形细胞增多;培养早期MCC的面积较小,大小较为均一;细胞的增殖速度随着传代次数的增加而逐渐减慢;1－3代Ⅱ型胶原的表达率较高,第7代后Ⅰ型胶原的表达率增加。结论：MCC在体外培养时的细胞形态大小的变化、Ⅰ、Ⅱ型胶原表达的更迭等特征与体内MCC从增殖层向钙化软骨层的变化特征近似。MCC在体外培养末期可发生分化。

The phenotypecharacteristic of mandibular condylar chondrocytes in vitro

Objective: To study the phenotype characteristic of mandibular condylar chondrocytes (MCCs) in vitro. Methods: MCCs of two-week-old New Zealand rabbits were isolated with enzyme digestion and cultured in DMEM. Phase contrast microscopy, image analysis system, MTT assay and immunocytochemistry method were used to compare MCCs of different passages in cellular shape and size, growth curve and expression of type I and type II collagen. Results: The majority of MCCs in earlier passages (1～3 passage) were polygonal, while more fusiform and spindle-shaped cells were found after 5～6 passages. MCCs in earlier passages were smaller than those in sixth passages. The proliferation rate of MCCs decreased with passaging. There were more type II collagen positive cells in 1 ～ 3 passages, while more type I collagen positive cells in 7th passage. Conclusion: The changing characters of MCCs in vitro such as cellular shape and size and expression of type I and II collagen are similar to those of MCCs in vivo from proliferating zone to hypertrophic zone. MCCs in later passages may be with dedifferentiation.