Krebsbach P H, Kuznetsov S A, Satomura K, Emmons R V, Rowe D W, Robey P G
Laboratory of Developmental Biology and Bone Research Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892, USA.
Transplantation. 1997 Apr 27;63(8):1059-69. doi: 10.1097/00007890-199704270-00003.
Marrow stromal fibroblasts (MSFs) are known to contain bone precursor cells. However, the osteogenic potential of human MSFs has been poorly characterized. The aim of this study was to compare the osteogenic capacity of mouse and human MSFs after implantation in vivo.
After in vitro expansion, MSFs were loaded into a number of different vehicles and transplanted subcutaneously into immunodeficient mice.
Mouse MSFs transplanted within gelatin, polyvinyl sponges, and collagen matrices all formed a capsule of cortical-like bone surrounding a cavity with active hematopoiesis. In transplants of MSFs from transgenic mice harboring type I procollagen-chloramphenicol acetyltransferase constructs, chloramphenicol acetyltransferase activity was maintained for up to 14 weeks, indicating prolonged bone formation by transplanted MSFs. New bone formation by human MSFs was more dependent on both the in vitro expansion conditions and transplantation vehicles. Within gelatin, woven bone was observed sporadically and only after culture in the presence of dexamethasone and L-ascorbic acid phosphate magnesium salt n-hydrate. Consistent bone formation by human MSFs was achieved only within vehicles containing hydroxyapatite/tricalcium phosphate ceramics (HA/TCP) in the form of blocks, powder, and HA/TCP powder-type I bovine fibrillar collagen strips, and bone was maintained for at least 19 weeks. Cells of the new bone were positive for human osteonectin showing their donor origin. HA/TCP powder, the HA/TCP powder-type I bovine fibrillar collagen strips, and HA/TCP powder held together with fibrin were easier to load and supported more extensive osteogenesis than HA/TCP blocks and thus may be more applicable for therapeutic use.
In this article, we describe the differences in the requirements for mouse and human MSFs to form bone, and report the development of a methodology for the consistent in vivo generation of extensive bone from human MSFs.
已知骨髓基质成纤维细胞（MSFs）含有骨前体细胞。然而，人类MSFs的成骨潜能尚未得到充分表征。本研究的目的是比较小鼠和人类MSFs在体内植入后的成骨能力。
体外扩增后，将MSFs加载到多种不同载体中，然后皮下移植到免疫缺陷小鼠体内。
移植到明胶、聚乙烯海绵和胶原基质中的小鼠MSFs均形成了一层皮质样骨包膜，围绕着一个具有活跃造血功能的腔隙。在携带I型前胶原-氯霉素乙酰转移酶构建体的转基因小鼠的MSFs移植中，氯霉素乙酰转移酶活性维持了长达14周，表明移植的MSFs骨形成持续时间延长。人类MSFs的新骨形成更依赖于体外扩增条件和移植载体。在明胶中，仅在存在地塞米松和L-抗坏血酸磷酸镁盐n水合物的情况下培养后，才偶尔观察到编织骨。仅在含有块状、粉末状羟基磷灰石/磷酸三钙陶瓷（HA/TCP）以及HA/TCP粉末-I型牛纤维状胶原条的载体中，人类MSFs才能持续形成骨，并且骨维持至少19周。新骨细胞的人骨连接蛋白呈阳性，表明其供体来源。与HA/TCP块相比，HA/TCP粉末、HA/TCP粉末-I型牛纤维状胶原条以及与纤维蛋白结合的HA/TCP粉末更易于加载，并且支持更广泛的成骨作用，因此可能更适用于治疗用途。
在本文中，我们描述了小鼠和人类MSFs形成骨的要求差异，并报告了一种从人类MSFs在体内持续生成大量骨的方法的开发。
