Abstract：
The differentiation of bone marrow stromal cells (BMSCs) into Schwann-like cells (SCLCs) has the potential to promote the structural and functional restoration of injured axons. However, the optimal induction protocol and its underlying mechanisms remain unclear. This study aimed to compare the effectiveness of different induction protocols in promoting the differentiation of rat BMSCs into SCLCs and to explore their potential mechanisms. BMSCs were induced using two distinct methods: a composite factor induction approach (Protocol-1) and a conditioned culture medium induction approach (Protocol-2). The expression of Schwann cells (SCs) marker proteins and neurotrophic factors (NTFs) in the differentiated cells was assessed. Cell proliferation and apoptosis were also measured. During induction, changes in miR-21 and Sprouty RTK signaling antagonist 2 (SPRY2) mRNA were analyzed. Following the transfection of BMSCs with miR-21 agomir or miR-21 antagomir, induction was carried out using both protocols, and the expression of SPRY2, ERK1/2, and SCs marker proteins was examined. The results revealed that NTFs expression was higher in Protocol-1, whereas SCs marker proteins expression did not significantly differ between the two groups. Compared to Protocol-1, Protocol-2 exhibited enhanced cell proliferation and fewer apoptotic and necrotic cells. Both protocols showed a negative correlation between miR-21 and SPRY2 expression throughout the induction stages. After induction, the miR-21 agomir group exhibited reduced SPRY2 expression, increased ERK1/2 expression, and significantly elevated expression of SCs marker proteins. This study demonstrates that Protocol-1 yields higher NTFs expression, whereas Protocol-2 results in stronger SCLCs proliferation. Upregulating miR-21 suppresses SPRY2 expression, activates the ERK1/2 signaling pathway, and promotes BMSC differentiation into SCLCs.
摘要：
骨髓基质细胞（BMSCs）向雪旺样细胞（SCLCs）的分化具有促进受损轴突结构和功能恢复的潜力。然而,最佳诱导方案及其潜在机制尚不清楚.本研究旨在比较不同诱导方案促进大鼠BMSCs向SCLCs分化的效果，并探讨其可能的机制。使用两种不同的方法诱导BMSC:复合因子诱导方法(方案-1)和条件培养基诱导方法(方案-2)。评估了施旺细胞（SC）标记蛋白和神经营养因子（NTFs）在分化细胞中的表达。还测量了细胞增殖和凋亡。在感应过程中,分析了miR-21和SproutyRTK信号拮抗剂2（SPRY2）mRNA的变化。用miR-21agomir或miR-21antagomir转染BMSCs后，使用两种方案进行诱导，并检测SPRY2、ERK1/2和SCs标记蛋白的表达。结果表明，方案1中的NTFs表达较高，而两组之间的SCs标记蛋白表达没有显着差异。与方案-1相比,方案-2表现出增强的细胞增殖和较少的凋亡和坏死细胞。两种方案在整个诱导阶段显示miR-21和SPRY2表达之间的负相关。感应后,miR-21agomir组显示SPRY2表达降低，ERK1/2表达增加，SCs标记蛋白表达显著升高。这项研究表明，方案-1产生更高的NTFs表达，而方案-2导致更强的SCLCs增殖。上调miR-21抑制SPRY2表达，激活ERK1/2信号通路，并促进BMSC分化为SCLCs。
