Histochemical evidence of the initial chondrogenesis and osteogenesis in the periosteum of a rib fractured model: Implications of osteocyte involvement in periosteal chondrogenesis
Histochemical evidence of the initial chondrogenesis and osteogenesis in the periosteum of a rib fractured model: Implications of osteocyte involvement in periosteal chondrogenesis
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DOI：
10.1002/jemt.20088
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发表时间：
2004-07-01
影响因子：
2.5
通讯作者：
Maeda, T
中科院分区：
文献类型：
--
作者：
Li, MQ;Amizuka, N;Maeda, T
我们使用标准化的小鼠肋骨骨折模型，检查了骨折引起的骨膜软骨形成和成骨早期阶段的细胞事件。最初的细胞事件被认为是在称为骨膜“形成层”的较深层中的大量增殖，如大量增殖细胞核抗原阳性细胞所证明的。然后，骨膜软骨和骨直接从分化程度最高的细胞区域再生，即靠近和远离骨折部位的形成层的成熟成骨细胞。因此，骨膜破骨细胞似乎具有分化成软骨细胞和成骨细胞谱系的潜力。 CD31阳性血管均匀地分布在正在再生软骨和骨的骨膜上，因此表明对骨软骨形成起始的影响较小。然而，相比之下，再生的骨膜软骨或从皮质骨延伸的骨分别包括死的或活的骨细胞。在再生软骨附近发现了空的腔隙和嵌入无定形材料的腔隙，而完整的骨细胞则持续存在于再生骨附近。嵌入的具有无定形材料的腔隙会使组织液、营养物质、氧气和几种分泌因子（例如牙本质基质蛋白-1）无法输送到通过间隙连接将骨细胞互连的骨膜成骨细胞。因此，我们的研究为骨折反应的初始细胞事件提供了两个主要线索：骨膜成骨细胞分化为软骨形成谱系的潜力，以及骨膜软骨和骨再生中骨细胞的推定参与。显微镜。资源。技术。 64：330-342，2004。 (C) 2004 Wiley-Liss, Inc.
We have examined cellular events at the early stages of periosteal chondrogenesis and osteogenesis induced by bone fracture, using a well-standardized rib fracture model of the mouse. The initial cellular event was recognized as considerable proliferation in the deeper layer referred to as the "cambium layer" of the periosteum, as evidenced by numerous proliferating cell nuclear antigen-positive cells. The periosteal cartilage and bone were then regenerated directly from the region, of the most-differentiated cell, i.e., mature osteoblasts of the cambium layer both close to and distant from the fracture site. Therefore, periosteal osteohlasts appeared to have the potential to differentiate into chondrogenic and osteoblastic lineages. CD31-positive blood vessels were uniformly localized along the periosteum that was regenerating cartilage and bone, being therefore indicative of less influence on the initiation of osteochondrogenesis. In contrast, however, the regenerated periosteal cartilage or bone extended from the cortical bones included dead or living osteocytes, respectively. Empty lacunae and lacunae embedded with amorphous materials were found close to the regenerated cartilage, while intact osteocytes persisted adjacent to the regenerated bone. The embedded lacunae with amorphous materials would render the tissue fluid, nutrients, oxygen, and several secretory factors such as dentin matrix protein-1 impossible to be delivered to the periosteal osteoblasts that interconnect osteocytes via gap junctions. Our study thus provides two major clues on initial cellular events in response to bone fracture: the potentiality of periosteal osteoblastic differentiation into a chondrogenic lineage, and a putative involvement of osteocytes in periosteal cartilage and bone regeneration. Microsc. Res. Tech. 64: 330-342,2004. (C) 2004 Wiley-Liss, Inc.