Kimura Kenichi, Breitbach Martin, Schildberg Frank A, Hesse Michael, Fleischmann Bernd K
Institute of Physiology I, Life & Brain Center, Medical Faculty, University of Bonn, D-53105 Bonn, Germany.
Department of Cardiac Surgery, University Hospital Bonn, D-53127 Bonn, Germany.
Bone Rep. 2021 Sep 29;15:101133. doi: 10.1016/j.bonr.2021.101133. eCollection 2021 Dec.
Mesenchymal stem cells (MSCs) are multipotent and considered to be of great potential for regenerative medicine. We could show recently (Breitbach, Kimura et al. 2018) that a subpopulation of MSCs as well as sinusoidal endothelial cells (sECs) in the bone marrow (BM) of CD73-EGFP reporter mice could be labeled . We took advantage of this model to explore the plasticity and osteogenic potential of CD73-EGFP MSCs and their role in the regenerative response upon bone lesion . Herein we show that isolated CD73-EGFP MSCs displayed more pronounced stemness and stronger differentiation capacity into the osteogenic lineage compared to CD73-EGFP MSCs. In a bone fracture model, endogenous BM-resident CD73-EGFP MSCs were found to migrate to the fracture site and differentiate into cartilage and bone cells. Our analysis also showed that CD73-EGFP sECs contributed to the neovascularization of the fracture site. In addition, grafting of CD73-EGFP MSCs into acute bone lesions revealed their capacity to differentiate into chondrocytes and osteocytes and their contribution to callus formation in the regeneration process of fracture healing. Thus, CD73 MSCs display enhanced stemness and osteogenic differentiation potential and illustrating a prominent role of the CD73 MSC subpopulation to promote fracture repair.
间充质干细胞（MSCs）具有多能性，被认为在再生医学中具有巨大潜力。我们最近（Breitbach、Kimura等人，2018年）能够证明，CD73-EGFP报告基因小鼠骨髓（BM）中的间充质干细胞亚群以及窦状内皮细胞（sECs）可以被标记。我们利用这个模型来探索CD73-EGFP间充质干细胞的可塑性和成骨潜力，以及它们在骨损伤再生反应中的作用。在此我们表明，与CD73-EGFP间充质干细胞相比，分离出的CD73-EGFP间充质干细胞表现出更明显的干性和更强的向成骨谱系分化的能力。在骨折模型中，发现内源性骨髓驻留CD73-EGFP间充质干细胞迁移到骨折部位并分化为软骨细胞和骨细胞。我们的分析还表明，CD73-EGFP窦状内皮细胞促成了骨折部位的新血管形成。此外，将CD73-EGFP间充质干细胞移植到急性骨损伤中，揭示了它们分化为软骨细胞和骨细胞的能力，以及它们在骨折愈合再生过程中对骨痂形成的贡献。因此，CD73间充质干细胞表现出增强的干性和成骨分化潜力，说明CD73间充质干细胞亚群在促进骨折修复中发挥着重要作用。
