Molecular biological analyses of cranio-maxillo-facial bone metabolism and application of the gene therapy

人骨髓间充质干细胞（hMSCs）具有高度增殖性，并且通过应用骨形态发生蛋白-2（BMP-2）和碱性成纤维细胞生长因子（bFGF）来调节细胞周期。BrDU、PCNA（proliferating cell nuclear antigen）和PTTG（pituitary tumor transforming gene）等细胞周期基因分别在完整期、G 0/G1期和G2/M期表达。超微结构分析显示，hMSC在BMP-2给药后通过改变细胞核（常染色质到异染色质）和细胞质（滑面内质网到颗粒状内质网）形态而分化。在使用hMSCs和适当的支架如天然明胶的再生医学中，存在加速的颅骨再生以及BMP-2和bFGF_的启动。在成骨培养基培养物（含有地塞米松、抗坏血酸和β-甘油磷酸盐）中，在上清液和细胞中均观察到碱性磷酸酶（ALP）的高表达水平。移植后4周，hMSCs和成骨细胞因子均显示人碱性磷酸酶和骨钙素的免疫组化表达，骨量增加。这些结果可能解释了hMSCs在成骨谱系的再生医学中的应用。在未来，这种方案可能会与基因治疗的hMSCs严重异常的骨代谢。

The human modesenchymal stem cells,(hMSCs) are highly proliferative and cell-cycle regulated by applications of bone morphogenetic protein-2 (BMP-2) and basic fibroblast growth factor (bFGF). The gene expressions of the cell cycles such as BrDU, PCNA (proliferating cell nuclear antigen) and PTTG (pituitary tumor transforming gene) are well demonstrated at entire, GO/G1 and G2/M phase, respectively. Ultrastrucural analyses revealed that hMSCs are differentiated upon BMP-2 administration by changing the nuclear (of euchromatin to heterochromatin) and cytoplasmic (smooth endoplasmic reticulum to granular endoplasmic reticulum) morphology. In regenerative medicine using hMSCs and the proper scaffold such as a natural gelatin, there are accelerated cranial bone regeneration together with BMP-2 and bFGF_initiations. High expression levels of alkaline phosphatase (ALP) in osteogenic medium culture, which contains dexamethasone, ascorbic acid, and beta-glycerophosphate, observed in both supernatant and cells. In 4 weeks after transplanting hMSCs and osteogenic cytokines demonstrated the significant immunohistochemical expressions of human ALP and osteocalcin as well as increased bone mass. These results may explain that hMSCs are useful in regenerative medicine in osteogenic lineage. In future, this regimen may be used in conjunction with gene therapy on hMSCs for severe abnormal bone metabolism.