Zheng Li, Yamashiro Takashi, Fukunaga Tomohiro, Balam Tarek A, Takano-Yamamoto Teruko
Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Medicine and Dentistry, Okayama University, Okayama, Japan.
Eur J Oral Sci. 2005 Aug;113(4):318-25. doi: 10.1111/j.1600-0722.2005.00226.x.
Mandibular condylar cartilage differs from primary cartilage in morphological organization of the chondrocytes and in responses to biomechanical stress and humoral factors. For the first time, we describe the expression of Bmp3 mRNA in relation to types I, II and X collagen mRNA (as determined by in situ hybridization) in chondrocytes of the rat mandibular condylar cartilage, femoral articular cartilage, femoral growth plate cartilage, and temporal cartilage, which transiently appeared in the reparative response stage of mandibular ramus fracture healing. In all cartilages evaluated, Bmp3 was expressed in proliferating chondrocytes that expressed type I collagen in condylar cartilage, articular cartilage, and temporal cartilage appearing during fracture healing. Bmp3 was also found in hypertrophic chondrocytes that expressed type X collagen mRNA in all cartilages evaluated. Furthermore, in remodeling bone, Bmp3 mRNA was strongly expressed in active osteoblast cells in periosteal reaction layers formed after fracture. These findings suggest that Bmp3 expression in a special layer of typical articular cartilage may be regulated by mechanical stress stimulation. We also found that Bmp3 was expressed in the periosteal layers of the bone segments near the fracture site during fracture healing.
下颌髁突软骨在软骨细胞的形态组织以及对生物力学应力和体液因子的反应方面与原发性软骨不同。我们首次描述了大鼠下颌髁突软骨、股骨关节软骨、股骨生长板软骨和颞软骨的软骨细胞中Bmp3 mRNA与I型、II型和X型胶原mRNA的表达关系（通过原位杂交确定），Bmp3 mRNA在髁突骨折愈合的修复反应阶段短暂出现。在所有评估的软骨中，Bmp3在增殖软骨细胞中表达，这些增殖软骨细胞在骨折愈合过程中出现在髁突软骨、关节软骨和颞软骨中并表达I型胶原。在所有评估的软骨中，在表达X型胶原mRNA的肥大软骨细胞中也发现了Bmp3。此外，在重塑骨中，Bmp3 mRNA在骨折后形成的骨膜反应层中的活跃成骨细胞中强烈表达。这些发现表明，典型关节软骨特殊层中Bmp3的表达可能受机械应力刺激调节。我们还发现，在骨折愈合过程中，Bmp3在骨折部位附近骨段的骨膜层中表达。
