骨髓间充质干细胞诱导为类许旺细胞的细胞外基质促进周围神经损伤后轴突再生

Extracellular matrix of Schwann-like cells induced by bone marrow mesenchymal stem cells promotes axonal regeneration after peripheral nerve injury

背景:既往研究发现许旺细胞及骨髓间充质干细胞诱导的类许旺细胞可以促进外周神经损伤后轴突的再生及功能恢复,而由于许旺细胞来源有限而限制了其应用,而且类许旺细胞外基质用于周围神经损伤的治疗鲜有报道。目的:探讨类许旺细胞外基质是否有助于周围神经损伤后的神经修复。方法:提取SD大鼠许旺细胞和骨髓间充质干细胞,将骨髓间充质干细胞诱导分化为类许旺细胞,并进行细胞鉴定和制备细胞外基质,在体外环境下将背根神经节神经元和背根神经节组织块接种于细胞外基质上,观察神经轴突生长情况。制备SD大鼠坐骨神经缺损模型,分别用自体神经、类许旺细胞外基质复合聚ε-己内酯导管(诱导组)、许旺细胞外基质复合聚ε-己内酯导管(许旺组)桥接,观察坐骨神经轴突再生及腓肠肌恢复情况。结果与结论:①与骨髓间充质干细胞比较,类许旺细胞p75NTR明显表达(P<0.05),许旺细胞纯度为(95.20±4.63)%;②类许旺细胞外基质和许旺细胞外基质能够在体外环境下促进背根神经节神经元与组织块神经轴突的生长;③体内实验中自体神经组再生神经纤维连贯且排列有序;诱导组和许旺组再生神经纤维贯通缺损区域,与自体神经组类似;④结果表明,类许旺细胞和许旺细胞的细胞外基质能够促进周围神经损伤后轴突再生及修复,为周围神经损伤提供了一种新的来源方便的无细胞疗法。

BACKGROUND:Previous studies have found that Schwann cells and bone marrow mesenchymal stem cells-derived Schwann cells can promote axonal regeneration and functional recovery after peripheral nerve injury.However,the shortage of Schwann cells limited its application.Schwann-like cells-derived extracellular matrix is rarely reported in the treatment of peripheral nerve injury.OBJECTIVE:To investigate whether Schwann-like cells-derived extracellular matrix contributes to nerve repair after peripheral nerve injury.METHODS:Schwann cells and bone marrow mesenchymal stem cells were extracted from SD rats and the latter were induced into Schwann-like cells,then both were identified to prepare extracellular matrix.in vitro,dorsal root ganglion neurons and dorsal root ganglion tissue blocks were seeded on extracellular matrix to observe the growth of dorsal root ganglion axons.The sciatic nerve defect models of SD rats were established.The sciatic nerve axon regeneration and gastrocnemius muscle recovery were observed by using autologous nerve,Schwann-like cells-derived extracellular matrix composite poly(ε-caprolactone)conduit(induction group)and Schwann cells-derived extracellular matrix composite poly(ε-caprolactone)conduit(Schwann group)respectively.RESULTS AND CONCLUSION:(1)The expression of p75NTR in Schwann-like cells was significantly higher than that in bone marrow mesenchymal stem cells(P<0.05).The purity of Schwann cells was(95.20±4.63)%.(2)Schwann-like cells-derived extracellular matrix and Schwann cells-derived extracellular matrix could promote the growth of nerve axons in dorsal root ganglion tissue block in vitro.(3)in vivo experiment,regenerated nerve fibers in autologous nerve group were continuous and orderly arranged;regenerated nerve fibers in induction group and Schwann group penetrated through the defect area,similar to that in the autologous nerve group.(4)The results showed that Schwann-like cells-derived extracellular matrix and Schwann cells-derived extracellular matrix could promote axon regeneration and repair after peripheral nerve injury,which provided a new and convenient cell-free therapy for peripheral nerve injury.