Department of Osteoporosis and Bone Disease, Huadong Hospital Affiliated to Fudan University, Research Section of Geriatric Metabolic Bone Disease, Shanghai Geriatric Institute, Shanghai, China.
PLoS One. 2019 Dec 10;14(12):e0226163. doi: 10.1371/journal.pone.0226163. eCollection 2019.
PTH1-34 (parathyroid hormone 1-34) is the only clinical drug to promote osteogenesis. MSCs (mesenchymal stem cells) have multidirectional differentiation potential and are closely related to fracture healing. This study was to explore the effects of PTH1-34 on proliferation and differentiation of endothelial cells and MSCs in vitro, and on angiogenesis, and MSCs migration during fracture healing in vivo.
Mice with stabilized fracture were assigned to 4 groups: CON, PTH (PTH1-34 40 μg/kg/day), MSC (transplanted with 105 MSCs), PTH+MSCs. Mice were sacrificed 14 days after fracture, and callus tissues were harvested for microCT scan and immunohistochemistry analysis. The effects of PTH1-34 on angiogenesis, and MSCs differentiation and migration were assessed by wound healing, tube formation and immunofluorescence staining.
Treatment with either PTH1-34, or MSCs promoted bone healing and vascular formation in fracture callus. The callus bone mass, bone volume, and bone mineral density were all greater in PTH and/or MSC groups than they were in CON (p<0.05). PTH1-34 increased small vessels formation (diameter ≤50μm), whereas MSCs increased the large ones (diameter >50μm). Expression of CD31 within calluses and trabecular bones were significantly higher in PTH1-34 treated group than that of not (p<0.05). Expression of CD31, VEGFR, VEGFR2, and vWF was upregulated, and wound healing and tube formation were increased in MSCs treated with PTH1-34 compared to that of control.
PTH1-34 improved the proliferation and differentiation of endothelial cells and MSCs, enhancing migration of MSCs to bone callus to promote angiogenesis and osteogenesis, and facilitating fracture healing.
甲状旁腺素 1-34（PTH1-34）是唯一促进成骨的临床药物。间充质干细胞（MSCs）具有多向分化潜能，与骨折愈合密切相关。本研究旨在探讨 PTH1-34 对体外内皮细胞和 MSCs 的增殖和分化，以及体内骨折愈合过程中的血管生成和 MSCs 迁移的影响。
将稳定骨折的小鼠分为 4 组：CON、PTH（PTH1-34 40 μg/kg/天）、MSC（移植 105 个 MSCs）、PTH+MSC。骨折后 14 天处死小鼠，采集骨痂组织进行 microCT 扫描和免疫组织化学分析。通过划痕愈合、管形成和免疫荧光染色评估 PTH1-34 对血管生成、MSCs 分化和迁移的影响。
PTH1-34 或 MSCs 的治疗均促进了骨折骨痂中的骨愈合和血管形成。与 CON 组相比，PTH 和/或 MSC 组的骨痂骨量、骨体积和骨密度均更大（p<0.05）。PTH1-34 增加了小血管形成（直径≤50μm），而 MSCs 增加了大血管形成（直径>50μm）。与未处理组相比，PTH1-34 处理组骨痂和小梁骨中的 CD31 表达显著升高（p<0.05）。与对照组相比，PTH1-34 处理的 MSCs 中 CD31、VEGFR、VEGFR2 和 vWF 的表达上调，伤口愈合和管形成增加。
PTH1-34 可促进内皮细胞和 MSCs 的增殖和分化，促进 MSCs 向骨痂迁移，从而促进血管生成和骨生成，促进骨折愈合。
