Periosteal stem cells are critical for bone regeneration, while the numbers will decrease with age. This study focused on whether Prx1⁺ cell, a kind of periosteal stem cell, could stimulate bone regeneration in aged mice. Four weeks and 12 months old Prx1CreER‐GFP; Rosa26^tdTomato mice were used to reveal the degree of Prx1⁺ cells participating in the femoral fracture healing procedure. One week, 8 weeks, 12 and 24 months old Prx1CreER‐GFP mice were used to analyse the real‐time distribution of Prx1⁺ cells. Twelve months old C57BL/6 male mice (n = 96) were used to create the bone defect model and, respectively, received hydrogel, hydrogel with Prx1⁻ mesenchymal stem cells and hydrogel with Prx1⁺ cells. H&E staining, Synchrotron radiation‐microcomputed tomography and mechanical test were used to analyse the healing results. The results showed that tdTomato⁺ cells were involved in bone regeneration, especially in young mice. At the same time, GFP⁺ cells decreased significantly with age. The Prx1⁺ cells group could significantly improve bone regeneration in the murine bone defect model via directly differentiating into osteoblasts and had better osteogenic differentiation ability than Prx1⁻ mesenchymal stem cells. Our finding revealed that the quantity of Prx1⁺ cells might account for decreased bone regeneration ability in aged mice, and transplantation of Prx1⁺ cells could improve bone regeneration at the bone defect site.

中文翻译：

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骨膜祖细胞可以刺激老年鼠骨缺损模型的骨再生。

骨膜干细胞对于骨骼再生至关重要，而该数目会随着年龄的增长而减少。这项研究的重点是Prx1 ⁺细胞（一种骨膜干细胞）是否可以刺激衰老小鼠的骨再生。四周零十二个月的Prx1CreER-GFP; 使用Rosa26 ^tdTomato小鼠揭示参与股骨骨折愈合过程的Prx1 ⁺细胞的程度。使用一周，8周，12和24个月大的Prx1CreER-GFP小鼠来分析Prx1 ⁺细胞的实时分布。十二个月大的C57BL / 6雄性小鼠（n = 96）被用来创建分别骨缺损模型，并且，接收到的水凝胶，水凝胶用的Prx1 ^-间充质干与的Prx1细胞和水凝胶⁺细胞。使用H＆E染色，同步辐射微型计算机断层扫描和机械测试来分析愈合结果。结果表明，tdTomato ⁺细胞参与骨骼再生，尤其是在年轻小鼠中。同时，GFP ⁺细胞随着年龄的增长而显着下降。所述的Prx1 ⁺细胞群可以通过直接分化成成骨显著提高在鼠骨缺损模型的骨再生和具有比的Prx1更好的成骨分化的能力^-间充质干细胞。我们的发现表明，Prx1 ⁺细胞的数量可能解释了老年小鼠骨骼再生能力下降以及Prx1 ⁺移植的原因。 细胞可以改善骨缺损部位的骨再生。