Abstract:

Objective: To investigate the regularity of primary cilia distribution in growth plate during long bone development. Methods: Immunofluorescence staining was applied to label primary cilia in femur sections of 1-, 4- week-old mice to study the distribution of primary cilia in cartilage growth plates. Growth plate chondrocytes were cultured, and changes of primary cilia were observed during the process of hypertrophic differentiation induction; the proportion of ciliated chondrocytes was increased through serum-free starvation, and then hypertrophic differentiation induction were performed; the expression of hypertrophic chondrocyte markers was detected by real-time quantitative polymerase chain reaction (RT-qPCR) and immunofluorescence staining. Results: Ciliated chondrocytes of 1-, 4- week-old mice were mainly distributed in the resting layer, the proliferating layer and the anterior hypertrophy layer, and primary ciliated cells were significantly reduced in the hypertrophy layer. It was found that the proportion of ciliated cells decreased after hypertrophic differentiation induction in vitro. After raising the proportion of ciliated cells, chondrocyte fertilization was induced, and the expression of COL10 and Prg4, the marker gene of hypertrophic chondrocytes, was significantly reduced. Conclusion: The primary cilia mainly existed in the resting zone, proliferation zone and the prehypertrophy zone of the growth plate. The chondrocytes in hypertrophy zone have less primary cilia. Increasing the proportion of ciliated cells by serum-free starvation can reduce the expression of the marker genes of hypertrophic chondrocytes.

Key words: primary cilia, growth plate, chondrocyte

摘要：

目的： 探究长骨发育过程中初级纤毛在生长板的分布规律。方法： 对1、4周龄和8周龄的小鼠股骨切片进行免疫荧光染色，分析初级纤毛在生长板的分布规律；培养生长板软骨细胞并诱导其肥大化，研究该过程中初级纤毛的改变；通过无血清饥饿法提高有纤毛软骨细胞比例后诱导软骨细胞肥大化，通过实时荧光定量聚合酶链式反应（real-time quantitative polymerase chain reaction, RT-qPCR）和免疫荧光染色检测肥大软骨细胞标志物的表达。结果： 1、4周龄小鼠的有纤毛软骨细胞主要分布在静息层、增殖层和前肥大层，肥大层有初级纤毛细胞显著减少；在体外诱导软骨细胞肥大化后，有纤毛细胞比例降低；提高有纤毛细胞比例后诱导软骨细胞肥大化，肥大软骨细胞标志性基因COL10、Prg4表达降低。结论： 初级纤毛主要分布在生长板静息层、增殖层和前肥大层，肥大层软骨细胞初级纤毛减少；通过无血清饥饿法提高有纤毛细胞比例能够降低肥大软骨细胞标志性基因的表达。

关键词: 初级纤毛, 生长板, 软骨细胞