Wang Xujun, Li Feng, Niyibizi Christopher
Department of Orthopaedics and Rehabilitation, Division of Musculoskeletal SciencesPenn State College of Medicine, Mail Code H089, 500 University Drive, Hershey, Pennsylvania 17033, USA.
Stem Cells. 2006 Aug;24(8):1869-78. doi: 10.1634/stemcells.2005-0430. Epub 2006 May 4.
The potential of cell or gene therapy to treat skeletal diseases was evaluated through analysis of transplanted osteoprogenitors into neonatal homozygous and heterozygous osteogenesis imperfecta mice (oim). The osteoprogenitors used for transplantation were prepared by injection of mesenchymal stem cells (MSCs) marked with the green fluorescent protein (GFP) into normal mice with the subsequent retrieval of the cells at 35 days. The retrieved cells referred to here as osteoprogenitors were expanded in culture and transplanted into the 2-day-old oim mice via the superficial temporal vein. The recipient mice were evaluated at 2 and 4 weeks after cell transplantation. Four weeks after transplantation, tissue sections made from femurs and tibias of oim mice showed that the GFP-positive (GFP(+)) cells were distributed on the surfaces of the bone spicules in the spongiosa, the area of active bone formation. In the diaphysis, the GFP(+) cells were distributed in the bone marrow, on the endosteal surfaces, and also in the cortical bone. Immunofluorescence localization for GFP confirmed that the fluorescence seen in tissue sections was due to the engrafted donor cells, not bone autofluorescence. Gene expression analysis by polymerase chain reaction of the GFP(+) cells retrieved from the bones and marrow of the recipient mice demonstrated that the cells from bone were osteoblasts, whereas those from bone marrow were progenitors. These data demonstrate that MSCs delivered systemically to developing osteogenesis imperfecta mice engraft in bones, localize to areas of active bone formation, differentiate into osteoblasts in vivo, and may contribute to bone formation in vivo.
通过将移植的骨祖细胞注射到新生纯合子和杂合子成骨不全小鼠（oim）中，评估了细胞或基因疗法治疗骨骼疾病的潜力。用于移植的骨祖细胞是通过将标记有绿色荧光蛋白（GFP）的间充质干细胞（MSC）注射到正常小鼠体内，随后在35天时取出细胞而制备的。此处称为骨祖细胞的取出细胞在培养中进行扩增，并通过颞浅静脉移植到2日龄的oim小鼠体内。在细胞移植后2周和4周对受体小鼠进行评估。移植后4周，取自oim小鼠股骨和胫骨的组织切片显示，GFP阳性（GFP(+)）细胞分布在松质骨骨小梁表面，即活跃骨形成区域。在骨干中，GFP(+)细胞分布在骨髓、骨内膜表面以及皮质骨中。GFP的免疫荧光定位证实，组织切片中看到的荧光是由于移植的供体细胞，而非骨自身荧光。通过聚合酶链反应对从受体小鼠骨骼和骨髓中取出的GFP(+)细胞进行基因表达分析表明，来自骨骼的细胞是成骨细胞，而来自骨髓的细胞是祖细胞。这些数据表明，全身性递送的MSC移植到发育中的成骨不全小鼠体内后，可在骨骼中植入，定位于活跃骨形成区域，在体内分化为成骨细胞，并可能在体内促进骨形成。
