| 摘要: |
| 目的 探讨人脐带间充质干细胞（hucMSC）分泌的外泌体对骨折愈合的影响及作用机制。方法 取12只雄性SD大鼠构建胫骨骨折模型，将其随机分为3组，每组4只。各组大鼠分别于骨折术后7 d予以如下处理：空白对照组，骨髓腔内注射磷酸盐缓冲液；hucMSC-外泌体组，骨髓腔内注射hucMSC分泌的外泌体；hucMSC-上清组，骨髓腔内注射hucMSC的去外泌体培养上清。治疗3周后通过micro-CT检测和组织切片H-E染色评价大鼠骨折断端愈合情况，qPCR法检测骨组织中成骨标志基因骨钙素（OCN）、骨桥蛋白（OPN）、碱性磷酸酶（ALP）和Runt相关转录因子2（Runx-2）的表达。结果 活体micro-CT扫描结果显示，空白对照组、hucMSC-上清组大鼠的骨折断端尚未吻合，骨皮质外观不连续，骨折线明显；hucMSC-外泌体组大鼠的骨折断端对合良好，骨皮质外观较连续，骨折线基本消失。H-E染色结果显示，空白对照组、hucMSC-上清组大鼠的纤维骨痂尚未形成，新生骨小梁结构不明显；hucMSC-外泌体组大鼠已经形成完整的纤维骨痂结构，新生骨小梁结构较多、排列较为规则。hucMSC-外泌体组大鼠骨组织中OCN、OPN、ALP和Runx-2的表达量高于空白对照组和hucMSC-上清组，差异均有统计学意义（P均<0.05）。结论 hucMSC分泌的外泌体能促进骨折愈合，其机制可能与促进OCN、OPN、ALP和Runx-2表达有关。 |
| 关键词: 胫骨骨折 间充质干细胞 外泌体 骨折愈合 |
| DOI：10.16781/j.0258-879x.2018.07.0735 |
| 投稿时间：2018-05-14修订日期：2018-07-09 |
| 基金项目:国家自然科学基金（81572637）. |
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| Human umbilical cord mesenchymal stem cell-derived exosomes promotes fracture healing in rats |
| WANG Ren-kai1,CUI Hao-cheng1,WAN Dong-ling2,TANG Hao1* |
(1. Department of Orthopaedic Trauma, Changhai Hospital, Navy Medical University(Second Military Medical University), Shanghai 200433, China;
2. Department of Histology and Embryology, College of Basic Medical Sciences, Navy Medical University(Second Military Medical University), Shanghai 200433, China
*Corresponding author) |
| Abstract: |
| Objective To explore the effect of human umbilical cord mesenchymal stem cell (hucMSC)-derived exosomes on fracture healing and its related mechanisms. Methods Twelve male SD rats with tibial fracture were randomly divided into 3 groups with 4 rats in each group. The rats in control group were treated with phosphate buffer solution by intra-bone marrow injection on 7 day after fracture operation, the rats in hucMSC-exosome group were treated with hucMSC-derived exosomes, and the rats in hucMSC-supernatant group were treated with exosome-free hucMSC supernatant. After treatment for 3 weeks, the healing of fracture gap was evaluated by micro-CT examination and tissue section H-E staining, and the expression levels of osteogenesis-related genes osteocalcin (OCN), osteopontin (OPN), alkaline phosphatase (ALP) and Runt-related transcription factor 2 (Runx-2) were detected by qPCR. Results Micro-CT examination showed that fracture was not been joined in the control group and the hucMSC-supernatant group, with clear fracture line and discontinuous wall of cortical bone, while fracture was anastomosed in the hucMSC-exosome group, with continuous wall of cortical bone and disappeared fracture line. Tissue section H-E staining showed no fibrous callus or structure of new bone trabeculae in the control group and the hucMSC-supernatant group, while complete fibrous callus was formed and structure of new bone trabeculae was in order in the hucMSC-exosome group. The expression levels of OCN, OPN, ALP, and Runx-2 in the hucMSC-exosome group were significantly higher than those in the control group and the hucMSC-supernatant group (all P<0.05). Conclusion HucMSC-derived exosomes can promote fracture healing of rats, which may be related to the upregulated expressions of OCN, OPN, ALP, and Runx-2. |
| Key words: tibial fractures mesenchymal stem cells exosomes fracture healing |
