Exosomes Secreted by Young Mesenchymal Stem Cells Promote New Bone Formation During Distraction Osteogenesis in Older Rats
Exosomes Secreted by Young Mesenchymal Stem Cells Promote New Bone Formation During Distraction Osteogenesis in Older Rats
复制标题
年轻间充质干细胞分泌的外泌体促进老年大鼠牵张成骨过程中新骨的形成
DOI：
10.1007/s00223-019-00656-4
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发表时间：
2020-02-26
影响因子：
4.2
通讯作者：
Chai, Yimin
中科院分区：
文献类型：
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作者：
Jia, Yachao;Qiu, Shuo;Chai, Yimin
牵张成骨是一种临床上有效的骨缺损修复方法。然而，治疗持续时间不期望地长，特别是在老年患者中。来源于间充质干细胞的外泌体（MSC-Exos）可以发挥有益的作用，同时避免干细胞移植可能出现的并发症。本研究旨在评价MSC-Exos对老年大鼠DO期间骨再生的影响。通过超速离心从年轻骨髓间充质干细胞（BMSCs）的上清液中分离外泌体，并使用透射电子显微镜、蛋白质印迹和可调电阻脉冲传感分析来表征。采用CCK-8法、碱性磷酸酶（ALP）和ARS染色、qRT-PCR等方法检测MSC-Exos对老年BMSCs增殖和分化的影响。建立老年SD大鼠单侧胫骨牵张模型，牵张后每周于牵张间隙局部注射MSC-Exos或磷酸盐缓冲液。采用X线片、Micro-CT、力学测试和组织学染色评价骨再生。MSC-Exos是直径为60 - 130 nm的圆形或杯状囊泡，表达的标志物包括CD 9、CD 63和TSG 101。体外实验结果表明，MSC-Exos能促进老年BMSCs的增殖和成骨分化。根据X线、显微CT和组织学分析的结果，MSC-Exos处理的大鼠的骨再生明显加速。MSC-Exos组的牵引胫骨也表现出更好的机械性能。这些结果表明，MSC-Exos通过增强BMSCs的增殖和成骨能力促进老年大鼠DO介导的骨再生。
Distraction osteogenesis (DO) is a clinically effective procedure to regenerate large bone defects. However, the treatment duration is undesirably lengthy, especially in elderly patients. Exosomes derived from mesenchymal stem cells (MSC-Exos) could exert the beneficial effects while avoiding the possible complications of stem cell transplantation. This study aimed to evaluate the effects of MSC-Exos on bone regeneration during DO in older rats. Exosomes were isolated from the supernatants of young bone marrow mesenchymal stem cells (BMSCs) through ultra-centrifugation, and characterized using transmission electron microscopy, western blot, and tunable resistive pulse sensing analysis. The effects of MSC-Exos on the proliferation and differentiation of older BMSCs were evaluated using CCK-8 assay, ALP and ARS staining, and qRT-PCR. Unilateral tibial DO model was established on older Sprague-Dawley rats and MSC-Exos or phosphate buffer saline was locally injected into the distraction gaps after distraction weekly. Bone regeneration were evaluated using X-ray, Micro-CT, mechanical test, and histological staining. The MSC-Exos were round or cup-shaped vesicles ranging from 60 to 130 nm in diameter and expressed markers including CD9, CD63, and TSG101. The in vitro results indicated that MSC-Exos could enhance the proliferation and osteogenic differentiation of older BMSCs. Bone regeneration was markedly accelerated in rats treated with MSC-Exos according to the results of X-ray, micro-CT, and histological analysis. The distracted tibias from the MSC-Exos group also demonstrated better mechanical properties. These results suggest that MSC-Exos promote DO-mediated bone regeneration in older rats through enhancing the proliferation and osteogenic capacity of BMSCs.