骨髓间充质干细胞外泌体通过PI3K/Akt通路修复大鼠皮瓣缺血再灌注损伤的实验研究  

Exosomes derived from bone marrow mesenchymal stem cells repair ischemia-reperfusion injury of skin flaps via PI3K/Akt pathway

作　　者：牛其芳 李德龙[2] 冯芝恩[2] 肖冉冉 韩正学[2] NIU Qi-fang;LI De-long;FENG Zhi-en;XIAO Ran-ran;HAN Zheng-xue(Department of Stomatology,Beijing Tiantan Hospital,Capital Medical University,Beijing 100070,China)

机构地区：[1]首都医科大学附属北京天坛医院口腔科,北京100070 [2]首都医科大学口腔医学院口腔颌面-头颈肿瘤科

出　　处：《北京口腔医学》2024年第4期241-246,共6页Beijing Journal of Stomatology

基　　金：国家自然科学基金(81974144,82370925);北京市属医院科研培育计划(PX2024056);首都医科大学附属北京口腔医院创新基金临床研究专项(23-09-19)。

摘　　要：目的探讨骨髓间充质干细胞外泌体(exosomes derived from bone marrow mesenchymal stem cell,BMSCs-Exos)通过PI3K/Akt通路修复皮瓣缺血再灌注损伤的机制。方法培养大鼠骨髓间充质干细胞(BMSCs),提取细胞上清液中的外泌体并通过电镜、粒径分析及免疫印迹实验进行鉴定。建立以腹壁浅动静脉为血管蒂的大鼠腹部皮瓣缺血再灌注损伤模型;将大鼠随机分为4组:Sham组、IR+PBS组、IR+Exo组及IR+Exo+LY组。术后观察并拍照记录大鼠皮瓣大体情况,第7天计算皮瓣坏死区比例;获取大鼠皮瓣组织样本,HE染色和组织评分评估皮瓣组织损伤程度,免疫组化评估皮瓣p-Akt、VEGFA表达水平和CD34标记的微血管密度。结果相比Sham组,IR+PBS组皮瓣坏死区比例增加,组织结构破坏加重,p-Akt及VEGFA表达水平下降,微血管密度降低;IR+Exo组皮瓣坏死和组织破坏水平降低,p-Akt及VEGFA表达上升,微血管密度增加;而PI3K抑制剂降低了BMSCs外泌体的修复作用,表现为皮瓣坏死增加,p-Akt及VEGFA表达下调,微血管密度减少。结论BMSCs外泌体对大鼠腹部皮瓣缺血再灌注损伤具有显著的保护和修复作用,PI3K/Akt信号通路可能是BMSCs外泌体治疗皮瓣缺血再灌注损伤的关键通路。Objective To explore the effect and mechanism of exosomes derived from bone marrow mesenchymal stem cells(BMSCs-Exos)repairinging ischemia-reperfusion injury in skin flaps through the PI3K/Akt pathway.Methods Exosomes were extracted from the supernatant of BMSCs and identified by transmission electron microscopy,particle size analysis,and Western blot.A rat abdominal flap ischemia-reperfusion injury model with superficial abdominal artery and vein pedicle was established.Rats were randomly divided into four groups:Sham,IR+PBS,IR+Exo,and IR+Exo+LY.The condition of the skin flaps was observed and recorded with a digital camera after surgery.On the 7th day,the necrotic rate of the flap was calculated,and then the flap tissues were harvested.The tissue morphology and damage were observed and scored from images by HE stains,and the expressions of p-Akt,VEGFA,and blood vessel density measured by CD34 were determined by immunohistochemistry.Results Compared with the Sham group,the IR+PBS group showed a significantly higher necrosis rate in the skin flaps,aggravated tissue structure damage,decreased p-Akt and VEGFA expression levels,and lower density of blood vessels.The necrosis rate of the flap and the damage level decreased while the p-Akt and VEGFA expression levels and the density of blood vessels increased when the BMSCs-Exos were used.The effects of BMSCs-Exos were weakened by LY294002,the inhibitor of the PI3K/Akt pathway.Conclusions The exosomes derived from BMSCs play an important role in protecting and repairing the skin flaps suffering ischemia-reperfusion injury,and the PI3K/Akt pathway may be the key to it.

关 键 词：骨髓间充质干细胞 外泌体 皮瓣 缺血再灌注损伤 PI3K/AKT通路 

分 类 号：R681.1[医药卫生—骨科学]