Group of Vascular Regeneration Research, Institute of Biomedical Research and Innovation, Kobe, Hyogo, Japan.
Lab Invest. 2010 Apr;90(4):637-49. doi: 10.1038/labinvest.2010.39. Epub 2010 Feb 15.
Adipose tissue is one of the promising sources of multipotent stem cells in human. Human multipotent adipose-derived stem (hMADS) cells have recently been isolated and showed differentiation potential into multiple mesenchymal lineages in vitro and in vivo. On the basis of these evidences, we examined the therapeutic efficacy of hMADS cells for fracture healing in an immunodeficient rat femur non-union fracture model. Local transplantation of hMADS cells radiographically and histologically promoted fracture healing with significant improvement of biomechanical function at the fracture sites compared with local transplantation of human fibroblasts (hFB) or PBS administration. Histological capillary density and physiological blood flow by laser Doppler perfusion imaging were significantly greater in hMADS group than hFB and PBS groups. Expressions of intrinsic (rat) bone morphogenetic protein-2 (BMP-2), vascular endothelial growth factor (VEGF) and angiopoietin-1 in peri-fracture tissue were upregulated in hMADS group than other groups. In addition, presence of BMP-2 or VEGF activated the proliferation and migration of hMADS cells in vitro. These results indicate that hMADS cells stimulate the interaction between the transplanted cells and the resident cells stronger than other cells, and they promote fracture healing more effectively. Furthermore, immunohistochemistry for human-specific antibodies revealed direct differentiation of hMADS cells into osteoblasts or endothelial cells in newly formed callus or vasculature, respectively. RT-PCR for human-specific primers for osteogenic/endothelial markers also disclosed osteogenic and vasculogenic plasticity of the transplanted hMADS cells at the early stage of fracture healing. The present results suggest that transplantation of hMADS cells may become a useful strategy for cell-based bone regeneration in the future clinical setting.
脂肪组织是人类多能干细胞的有前途的来源之一。最近已经分离出人类多能脂肪源性干细胞（hMADS），并在体外和体内显示出向多种间充质谱系分化的潜力。基于这些证据，我们在免疫缺陷型大鼠股骨骨不连骨折模型中检查了 hMADS 细胞治疗骨折愈合的疗效。与局部移植人成纤维细胞（hFB）或 PBS 给药相比，hMADS 细胞的局部移植在影像学和组织学上促进了骨折愈合，并显著改善了骨折部位的生物力学功能。激光多普勒灌注成像的组织学毛细血管密度和生理血流在 hMADS 组明显大于 hFB 和 PBS 组。hMADS 组骨折周围组织中内源性（大鼠）骨形态发生蛋白 2（BMP-2）、血管内皮生长因子（VEGF）和血管生成素 1 的表达高于其他组。此外，BMP-2 或 VEGF 的存在激活了 hMADS 细胞在体外的增殖和迁移。这些结果表明，hMADS 细胞比其他细胞更能刺激移植细胞与驻留细胞之间的相互作用，并更有效地促进骨折愈合。此外，针对人特异性抗体的免疫组化显示，hMADS 细胞直接分化为新形成的骨痂或脉管系统中的成骨细胞或内皮细胞。针对成骨/内皮标志物的人特异性引物的 RT-PCR 还揭示了移植 hMADS 细胞在骨折愈合早期的成骨和血管生成可塑性。这些结果表明，移植 hMADS 细胞可能成为未来临床环境中基于细胞的骨再生的有用策略。
