The effectiveness of autologous cell-based skeletal repair continues to be controversial in part because in vitro predictors of in vivo human bone formation by cultured human progenitor cells are not reliable. To assist in the development of in vivo assays of human osteoprogenitor potential, a fluorescence-based histology of nondecalcified mineralized tissue is presented that provides multiple criteria to distinguish human and host osteoblasts, osteocytes, and accumulated bone matrix in a mouse calvarial defect model. These include detection of an ubiquitously expressed red fluorescent protein reporter by the implanted human cells, antibodies specific to human bone sialoprotein and a human nuclear antigen, and expression of a bone/fibroblast restricted green fluorescent protein reporter in the host tissue. Using low passage bone marrow-derived stromal cells, robust human bone matrix formation was obtained. However, a striking feature is the lack of mouse bone marrow investment and osteoclasts within the human bone matrix. This deficiency may account for the accumulation of a disorganized human bone matrix that has not undergone extensive remodeling. These features, which would not be appreciated by traditional decalcified paraffin histology, indicate the human bone matrix is not undergoing active remodeling and thus the full differentiation potential of the implanted human cells within currently used mouse models is not being realized.

中文翻译：

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区分在小鼠骨骼修复缺陷内形成的人骨和小鼠骨的组织学标准。

基于自体细胞的骨骼修复的有效性仍存在争议，部分原因是培养的人祖细胞体内人骨形成的体外预测因子不可靠。为了协助开发人类骨祖细胞潜力的体内检测方法，提出了一种基于荧光的未脱钙矿化组织的组织学方法，该组织学提供了多种标准来区分小鼠颅盖缺损模型中的人和宿主成骨细胞，成骨细胞和积累的骨基质。这些包括通过植入的人类细胞检测遍在表达的红色荧光蛋白报告基因，对人骨唾液蛋白和人类核抗原具有特异性的抗体，以及在宿主组织中表达受骨/成纤维细胞限制的绿色荧光蛋白报告基因。使用低代骨髓来源的基质细胞，获得了坚固的人骨基质形成。然而，一个显着的特征是在人骨基质中缺乏小鼠骨髓的投资和破骨细胞。这种缺陷可能解释了未经广泛改造的杂乱无章的人骨基质的积累。这些特征，传统的脱钙石蜡组织学无法理解，表明人的骨基质未经历主动重塑，因此目前使用的小鼠模型中植入的人细胞的完全分化潜能尚未实现。这种缺陷可能解释了未经广泛改造的杂乱无章的人骨基质的积累。这些特征，传统的脱钙石蜡组织学无法理解，表明人的骨基质未经历主动重塑，因此目前使用的小鼠模型中植入的人细胞的完全分化潜能尚未实现。这种缺陷可能解释了未经广泛改造的杂乱无章的人骨基质的积累。这些特征，传统的脱钙石蜡组织学无法理解，表明人的骨基质未经历主动重塑，因此目前使用的小鼠模型中植入的人细胞的完全分化潜能尚未实现。