Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School, Okayama, Japan.
Sci Rep. 2019 Jul 29;9(1):10913. doi: 10.1038/s41598-019-47285-3.
In this study, we investigated the effect of CCN2 (cellular communication network factor 2), previously termed connective tissue growth factor, deposited in bone matrix on osteoclastogenesis and osteoblast differentiation. To mimic the bone matrix environment, osteocytic MLO-Y4 cells had been embedded in collagen-gel with recombinant CCN2 (rCCN2), and mouse macrophage-like RAW264.7 cells were inoculated on the gel and treated with receptor activator of NF-κB ligand (RANKL). NFATc1 and cathepsin K (CTSK) productions were more increased in the combination of RAW264.7 and MLO-Y4 cells treated with rCCN2 than the combination without rCCN2. Next, we isolated an osteocyte-enriched population of cells and osteoclast progenitor cells from wild type and tamoxifen-inducible Ccn2-deficient (KO) mice and performed similar analysis. NFATc1 and CTSK productions were decreased in the KO osteocyte-enriched population at 6 months after the tamoxifen injection, regardless of the origin of the osteoclast progenitor cells. Interestingly, CTSK production was rather increased in KO osteocytes at 1 year after the injection. Finally, the combination of osteoblastic MC3T3-E1 and MLO-Y4 cells in rCCN2-containing bone matrix revealed the up-regulation of osteoblastic marker genes. These findings suggest that CCN2 supplied by osteocytes regulates both osteoclastogenesis and osteoblast differentiation.
在这项研究中，我们研究了细胞通讯网络因子 2（以前称为结缔组织生长因子）在骨基质中的沉积对破骨细胞生成和成骨细胞分化的影响。为了模拟骨基质环境，将成骨细胞样 MLO-Y4 细胞嵌入含有重组 CCN2（rCCN2）的胶原凝胶中，并将鼠巨噬细胞样 RAW264.7 细胞接种在凝胶上，并接受核因子-κB 受体激活剂配体（RANKL）的处理。与没有 rCCN2 的组合相比，用 rCCN2 处理的 RAW264.7 和 MLO-Y4 细胞的组合中 NFATc1 和组织蛋白酶 K（CTSK）的产生增加更多。接下来，我们从野生型和他莫昔芬诱导型 Ccn2 缺陷（KO）小鼠中分离出富含成骨细胞的细胞和破骨细胞祖细胞，并进行了类似的分析。在他莫昔芬注射后 6 个月，无论破骨细胞祖细胞的来源如何，KO 成骨细胞富集群体中的 NFATc1 和 CTSK 产生均减少。有趣的是，注射后 1 年 KO 成骨细胞中的 CTSK 产生增加。最后，在含有 rCCN2 的骨基质中，成骨细胞样 MC3T3-E1 和 MLO-Y4 细胞的组合显示出成骨细胞标记基因的上调。这些发现表明，成骨细胞提供的 CCN2 调节破骨细胞生成和成骨细胞分化。
