Stetsiv Marta, Wan Matthew, Prabhu Shagun, Guzzo Rosa, Sanjay Archana
Department of Orthopedic Surgery, UConn School of Medicine, UConn Health, Farmington, CT 060630.
Department of Neuroscience, UConn School of Medicine, UConn Health, Farmington, CT 060630.
bioRxiv. 2024 Oct 25:2024.10.24.620082. doi: 10.1101/2024.10.24.620082.
Long bone injuries heal through either endochondral or intramembranous bone formation pathways. Unlike the endochondral pathway that requires a cartilage template, the process of intramembranous ossification involves the direct conversion of skeletal stem and progenitor cells (SSPCs) into bone-forming osteoblasts. There are limited surgical methods to model this process in experimental mice. Here, we have improved upon a bone marrow injury model in mice to facilitate the study of bone repair via intramembranous ossification and to assess postnatal regulators of osteogenesis. This method is highly reproducible and user-friendly, and it allows temporal assessment of new bone formation in a short period (3-7 days post-injury) using μCT and frozen section histology. Furthermore, the contributions of SSPCs and mature osteoblasts can be readily assessed using a combination of fluorescent reporter mice and this intramembranous bone marrow injury model. In clinical contexts, intramembranous bone formation is relevant for healing critical size defects, stress fractures, cortical defects, trauma from tumor resections, and joint replacements.
长骨损伤通过软骨内或膜内骨形成途径愈合。与需要软骨模板的软骨内途径不同，膜内成骨过程涉及骨骼干祖细胞（SSPCs）直接转化为成骨的成骨细胞。在实验小鼠中模拟这一过程的手术方法有限。在此，我们改进了小鼠骨髓损伤模型，以促进通过膜内成骨进行骨修复的研究，并评估出生后骨生成的调节因子。该方法具有高度可重复性且用户友好，它允许在短时间内（损伤后3 - 7天）使用μCT和冰冻切片组织学对新骨形成进行时间评估。此外，使用荧光报告小鼠和这种膜内骨髓损伤模型的组合，可以很容易地评估SSPCs和成熟成骨细胞的作用。在临床情况下，膜内骨形成与愈合临界尺寸缺损、应力性骨折、皮质缺损、肿瘤切除引起的创伤以及关节置换有关。
