Department of Osteomyelitis, Gansu Hospital of Traditional Chinese Medicine, Gansu, China.
Eur Rev Med Pharmacol Sci. 2019 Jun;23(11):4954-4960. doi: 10.26355/eurrev_201906_18086.
To investigate the role of human umbilical cord mesenchymal stem cell (hucMSC)-derived exosomes in the Wnt signaling pathway and their effects on fracture healing in rats.
A total of 24 healthy male Sprague-Dawley (SD) rats were randomly divided into 3 groups, of which the experimental groups were injected with Phosphate-Buffered Saline (PBS) and hUCMSC-derived exosomes, respectively, at the fracture site, and a blank control group was set. At 2 and 3 w after treatment, respectively, the healing condition at the fracture site in the rats was detected by micro-computed tomography (CT). The protein expressions of β-catenin and Wnt3a of the Wnt signaling pathway in the bone tissue were measured via Western blotting (WB) assay. Quantitative Real Time-fluorescence Polymerase Chain Reaction (qRT-PCR) was performed to determine the expressions of osteogenic marker genes [collagen type I (COL-1), osteopontin (OPN) and runt-related transcription factor 2 (RUNX2)].
The results of the micro-CT scan showed that the rats treated with exosomes had better apposition of the fracture site, and the appearance of cortical bone was continuous. The fracture sites in the blank control group and PBS injection group were not healed, and the appearance of cortical bone was discontinuous, with significant fracture lines. According to the WB results, the protein expression levels of β-catenin and Wnt3a in exosome treatment group were significantly higher than those in the blank control group and PBS injection group (p<0.01). The qRT-PCR results indicated that the expression levels of COL-1, OPN and RUNX2 in exosome treatment group were increased evidently compared with those in the other two groups (p<0.01).
HucMSC-derived exosomes are probably involved in the repair of fracture in rats through the Wnt signaling pathway.
探讨人脐带间充质干细胞（hucMSC）衍生的外泌体在 Wnt 信号通路中的作用及其对大鼠骨折愈合的影响。
将 24 只健康雄性 Sprague-Dawley（SD）大鼠随机分为 3 组，实验组分别在骨折部位注射磷酸盐缓冲液（PBS）和 hUCMSC 衍生的外泌体，空白对照组不做任何处理。分别在治疗后 2、3 周时，通过微计算机断层扫描（CT）检测大鼠骨折部位的愈合情况。采用 Western blot（WB）法检测骨组织中 Wnt 信号通路中β-catenin 和 Wnt3a 的蛋白表达。采用实时荧光定量聚合酶链反应（qRT-PCR）检测成骨标记基因[I 型胶原（COL-1）、骨桥蛋白（OPN）和 runt 相关转录因子 2（RUNX2）]的表达。
微 CT 扫描结果显示，外泌体治疗组骨折部位对位较好，皮质骨外观连续。空白对照组和 PBS 注射组骨折部位未愈合，皮质骨外观不连续，骨折线明显。WB 结果显示，外泌体治疗组β-catenin 和 Wnt3a 的蛋白表达水平明显高于空白对照组和 PBS 注射组（p<0.01）。qRT-PCR 结果表明，外泌体治疗组 COL-1、OPN 和 RUNX2 的表达水平明显高于其他两组（p<0.01）。
hucMSC 衍生的外泌体可能通过 Wnt 信号通路参与大鼠骨折的修复。
