Analysis of gene expression pattern and extracellular environment of connective tissue growth factor (CCN2/CTGF) during secondary ossification center formation

CCN 2/结缔组织生长因子（CCN 2）是间充质组织发育的关键信号调节剂。本研究探讨了小鼠胫骨骨骺次级骨化中心发育过程中CCN 2作为支持血管生成和软骨形成的因子的定位和表达。免疫组化显示CCN 2广泛分布于骺中心区的表达细胞周围，在那里软骨细胞变得肥大，软骨管进入肥大的肿块。此外，金属蛋白酶（MMP）9和硫酸乙酰肝素蛋白多糖（串珠素）和CCN 2的重叠分布被发现在次级骨化中心。这些发现表明，CCN 2参与建立骨骺血管化和重塑，最终决定发育中的骨骺软骨的次级骨化中心

CCN2/connective tissue growth factor (CCN2) is a critical signaling modulator of mesenchymal tissue development. This study investigated the localization and expression of CCN2 as a factor supporting angiogenesis and chondrogenesis during development of secondary ossification centers in the mouse tibial epiphysis. Immunostaining showed that CCN2 was distributed broadly around the expressed cells located in the central region of the epiphysis, where the chondrocytes become hypertrophic and the cartilage canal enters into the hypertrophic mass. Furthermore, an overlapping distribution of metalloproteinase (MMP)9 and Heparan sulfate proteoglycan(Perlecan) and CCN2 was found in the secondary ossification center. These findings suggest that the CCN2 is involved in establishing epiphyseal vascularization and remodeling, which eventually determines the secondary ossification center in the developing epiphysial cartilage