miR-210-5p修饰间充质干细胞源外泌体促进大鼠脊髓损伤修复的机制

Exosomes derived from miR-210-5p-modified mesenchymal stem cells promote recovery after spinal cord injury in rats

目的探索miR-210-5p修饰间充质干细胞(MSCs)源外泌体对脊髓损伤(SCI)大鼠的治疗作用。方法分离、培养SD大鼠MSCs,利用miRNA-210-5p mimic或NC mimic转染MSCs。随后,将60只成年雄性SD大鼠随机分为五组,假手术组、SCI组、MSCs组、MSCs-NC mimic组和miR-210-5p外泌体组,每组12只。用中度挫伤诱导SD大鼠SCI模型[8]。造模成功后,每天尾静脉注射200μL的MSCs外泌体或NC mimic外泌体或miR-210-5p外泌体;假手术组和SCI模型组每天尾静脉注射200μL的生理盐水溶液,连续7 d。采用BBB量表评估大鼠后肢运动功能;Western blot检测生长关联蛋白(GAP)-43、神经丝蛋白(NF)、Keap1和核因子E2相关因子2(Nrf2)蛋白的表达;RT-qPCR检测血红素加氧酶1(HO-1)、醌氧化还原酶(NQO1)的mRNA水平。结果与SCI模型组相比,miR-210-5p分泌体组大鼠的BBB评分显著升高(P<0.05)。进一步的研究发现,miR-210-5p分泌体组大鼠中GAP-43的表达被显著抑制(P<0.05),HO-1、NF、NQO1的表达则被增强(P<0.05),而Nrf2的抑制剂ML385逆转了miR-210-5p分泌体在SCI大鼠中的作用。结论miR-210-5p修饰MSCs源外泌体通过活化Keap1-Nrf-2通路促进大鼠的脊髓损伤修复。

Objective To explore the effects of exosomes derived from miR-210-5p-modified mesenchymal stem cells(MSCs)on spinal cord injury(SCI)in rats.Methods MSCs from SD rats were isolated and cultured,and were transfected with mirna-210-5p mimic or NC mimic.Subsequently,60 adult male SD rats were randomly divided into five groups with 12 rats in each group.Except the sham operation group,rats in other four groups underwent T10 laminectomy to construct SCI model.A total of 200 rats were injected with 200μL MSCs or MSCs NC mimic or miR-210-5p exosomes or normal saline into caudal vein every day after operation for 14 days.The motor function of hind limbs was evaluated by BBB scale.The expressions of growth associated protein(GAP)-43,neurofilament protein(NF),Keap1 and nuclear factor E2 related factor 2(Nrf2)were detected by Western blot.The mRNA levels of heme oxygenase-1(HO-1)and quinone oxidoreductase(NQO1)were detected by RT qPCR.Results Compared with the SCI model group,the BBB score of miR-210-5p secretory group was significantly higher(P<0.05).Further studies showed the expression of GAP-43 was significantly inhibited in the miR-210-5p secretory group,(P<0.05),while the expression of HO-1,NF and NQO1 was enhanced(P<0.05).Ml385,an inhibitor of Nrf2,reversed the role of miR-210-5p secretory in SCI rats.ConclusionmiR-210-5p modified MSCs derived exosomes promoted the repair of spinal cord injury in rats by activating keap1-nrf-2 pathway.