人脐带血干细胞外泌体对大鼠股骨头坏死的影响

Effects of human umbilical cord blood stem cell exosomes on femoral head necrosis in rats

[目的]探讨人脐带间充质干细胞外泌体(human umbilical cord mesenchymal stem cell-exosomes, hUCMSC-Exos)防治大鼠激素性股骨头坏死的疗效及其潜在机制。[方法] 36只雄性7周龄Sprague-Dawley大鼠随机分为3组,每组12只。空白对照组给予0.9%的盐水静脉注射;模型组给予静脉注射脂多糖(lipopolysaccharide, LPS)和甲泼尼龙(methylprednisolone,MPS)制备股骨头坏死模型;外泌体组在模型组给予的基础上,静脉注射hUCMSC-Exos。在第28 d处死大鼠,取股骨头行组织学Micro CT检测。[结果]透射电子显微镜和Western blot的检测表明,所提取分离物符合Exos基本特征。HE染色组织形态观察,三组的空骨陷窝率:模型组>外泌体组>空白对照组,差异均有统计学意义(P<0.05)。TUNEL染色成骨细胞凋亡率,模型组>外泌体组>空白对照组,差异均有统计学意义(P<0.05)。Micro CT检测方面,与空白对照组相比,模型组大鼠的BV/TV、Tb.Th、Tb.N数目均显著降低(P<0.05),而Tb.Sp显著升高(P<0.05);与模型组比较,外泌体组大鼠的BV/TV、Tb.Th、Tb.N数目均显著升高(P<0.05),而Tb.Sp显著降低(P<0.05)。[结论]人脐带间充质干细胞外泌体可能通过抑制成骨细胞凋亡,预防大鼠激素性股骨头坏死。

[Objective]To explore the role and potential mechanism of human umbilical cord mesenchymal stem cell-exosomes(hUC⁃MSC-exos)in the prevention and treatment of steroid-induced femoral head necrosis in rats.[Methods]A total of 367-week-old male Sprague-Dawley rats were randomly divided into 3 groups,with 12 rats in each group.The animals in the blank control group were given 0.9%normal saline intravenously,those in the model group was given lipopolysaccharide(LPS)and methylprednisolone(MPS)intravenous⁃ly to create the femoral head necrosis model,while those in the exosome group received hUCMSC-Exos intravenously on the basis of the drugs given in the model group.The rats were sacrificed 28 days later,and the femoral heads were harvested for histological observation and micro CT examination.[Results]Transmission electron microscopy and Western blot showed that the extracts isolated was consistent with the basic characteristics of exos.The empty rate of bone lacunae in three groups showed by HE staining was ranked up-down in order of the model group>the exosome group>the blank control group,with statistically significant differences between them(P<0.05).Apopto⁃sis rate of osteoblasts revealed by Tunel staining was also ranged up-down as the model group>the exosome group>the blank control group,which were statistically significant between them(P<0.05).Compared with the blank control group,the BV/TV,Tb.Th and Tb.N sig⁃nificantly decreased(P<0.05),while Tb.Sp significantly increased in the model group(P<0.05).Compared with the model group,the BV/TV,Tb.Th and Tb.N significantly increased(P<0.05),while Tb.Sp significantly decreased in the exosome group(P<0.05).[Conclusion]The exosomes obtained from human umbilical cord mesenchymal stem cells does prevent steroid-induced femoral head necrosis in rats by inhibiting osteoblast apoptosis in this study.