髁突增殖层细胞在颞下颌关节适应性改建中的作用

Effect of proliferative cells of condyle on the remodeling of temporomandibular joint

目的 探讨颞下颌关节盘前移位后髁突软骨增殖层细胞在关节适应性改建中的作用。方法 32只日本大白兔 ,在全麻下建立关节盘前移位动物模型 ,术后 1周、2周、4周、6周、8周处死 ,HE染色、Ⅱ型胶原和蛋白多糖聚合体mRNA原位杂交染色观察。结果 正常髁突的增殖层浅层有蛋白多糖聚合体mRNA的少许表达 ,但无Ⅱ型胶原表达。增殖层深层Ⅱ型胶原和蛋白多糖聚合体mRNA均有大量表达。术后 1周 ,受力区软骨组织变薄 ,尤以增殖层明显。蛋白多糖聚合体mRNA表达开始下调。 2周后Ⅱ型胶原mRNA表达也开始下降。 4周后蛋白多糖聚合体mRNA表达开始回升 ,增殖层浅层也可见表达 ,但Ⅱ型胶原mRNA表达继续下降。术后 8周两基因表达水平恢复至正常。结论 增殖层细胞具有向软骨细胞分化的潜能 ,成年兔髁突软骨增殖层具有再生能力 ,但损伤过度 ,可导致骨关节病样改变。

Objective To study the effect of proliferative cells of condyle on the remodeling of temporomandibular joint following disc displacement.Methods Thirty-two adult Japanese white rabbits were subjected to surgical operation of disc displacement. They were killed at 1 st ,2 nd ,4 th ,6 th ,8 th weeks after surgery respectively.Their temporomandibular joints were studied by histochemistry,and in situ hybridization of Aggrecan and collagen Ⅱ mRNA expression.Results Aggrecan mRNA expressed in superficial proliferative zone,but no collagen ⅡmRNA expression was found.Aggrecan and collagen Ⅱ mRNA coexpressed in deeper proliferative zone.The articular cartilage,especially proliferative zone,became thinner after 1 week after operation,then the expression of collagen Ⅱ mRNA was decreased.After 2 weeks aggrecan mRNA expression also was decreased.The aggrecan mRNA expression increased after 4 weeks and was detected in superfacial proliferative zone.But the expression of collagen Ⅱ mRNA continued to decrease.The expressions of Aggrecan and collagen Ⅱ mRNA were resumed after 8 weeks.Conclusion The proliferative cells in articular cartilage have potential capability of chondrification and can regenerate in adult rabbit.But severe damage maybe lead to osteoarthritis-like destructure.