摘要
目的探讨人脐带间充质干细胞(huc MSC)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;huc MSC-外泌体组,骨髓腔内注射huc MSC分泌的外泌体;huc MSC-上清组,骨髓腔内注射huc MSC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,q PCR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、huc MSC-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;huc MSC-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、huc MSC-上清组大鼠的纤维骨痂尚未形成,新生骨小梁结构不明显;huc MSC-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。huc MSC-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huc MSC-上清组,差异均有统计学意义(P均<0.05)。结论 huc MSC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。
Objective To explore the effect of human umbilical cord mesenchymal stem cell（huc MSC）-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 intrabone marrow injection on 7 day after fracture operation, the rats in huc MSC-exosome group were treated with huc MSCderived exosomes, and the rats in huc MSC-supernatant group were treated with exosome-free huc MSC 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 q PCR. Results Micro-CT examination showed that fracture was not been joined in the control group and the huc MSC-supernatant group, with clear fracture line and discontinuous wall of cortical bone, while fracture was anastomosed in the huc MSC-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 huc MSC-supernatant group, while complete fibrous callus was formed and structure of new bone trabeculae was in order in the huc MSC-exosome group. The expression levels of OCN, OPN, ALP, and Runx-2 in the huc MSC-exosome group were significantly higher than those in the control group and the huc MSC-supernatant group（all P〈0.05）. Conclusion Huc MSC-derived exosomes can promote fracture healing of rats, which may be related to the upregulated expressions of OCN, OPN, ALP, and Runx-2.
作者
王人楷
崔浩诚
万冬灵
唐昊
WANG Ren-kai;CUI Hao-cheng;WAN Dong-ling;TANG Hao(Department of Orthopaedic Trauma,Changhai Hospital,Navy Medical University（Second Military Medical University）,Shanghai 200433,China;Department of Histology and Embryology,College of Basic Medical Sciences,Navy Medical University（Second Military Medical University）,Shanghai 200433,China)
出处
《第二军医大学学报》
CAS
CSCD
北大核心
2018年第7期735-739,共5页
Academic Journal of Second Military Medical University
基金
国家自然科学基金(81572637)~~
关键词
胫骨骨折
间充质干细胞
外泌体
骨折愈合
tibial fractures
mesenchymal stem cells
exosomes
fracture healing
