Transplantation of olfactory ensheathing cells (OECs) has been shown to enhance synapse formation. However, the mechanisms underlying this effect are not completely understood. We performed profiling of the OEC and astrocyte secretomes via a proteomics approach, in case hevin secreted by astrocytes might be involved in the formation of synapses. Semi-quantitative proteomic analysis revealed that 25 proteins were highly expressed, and 22 were weakly expressed in OEC conditioned medium compared with astrocyte conditioned medium. These molecules are highly associated with neural differentiation and regeneration, enzyme regulatory activity, and growth factor binding. The quantification data of clusterin, fibronectin, hevin, insulin-like growth factor binding protein 2 and secreted protein acidic and rich in cysteine were further confirmed by western blotting. Moreover, the addition of hevin in the culture medium improved neurite sprouting and outgrowth of differentiated neural stem cells. The greater expression of hevin in OEC conditioned medium than in astrocyte conditioned medium was associated with a greater capacity of synaptic formation. Thus, our results indicate that soluble factors secreted by OECs provide a permissive environment for nerve repair, and hevin is one of the key molecules facilitating neurite sprouting and outgrowth.

中文翻译：

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嗅鞘细胞通过分泌高水平的hevin促进神经突的萌发和生长

嗅鞘细胞 (OEC) 的移植已被证明可以增强突触的形成。然而，这种效应背后的机制尚不完全清楚。我们通过蛋白质组学方法对 OEC 和星形胶质细胞分泌组进行了分析，以防星形胶质细胞分泌的 hevin 可能参与突触的形成。半定量蛋白质组学分析表明，与星形胶质细胞条件培养基相比，OEC 条件培养基中有 25 种蛋白质高表达，22 种蛋白质弱表达。这些分子与神经分化和再生、酶调节活性和生长因子结合高度相关。凝聚素、纤连蛋白、hevin、蛋白质印迹进一步证实了胰岛素样生长因子结合蛋白 2 和分泌蛋白酸性且富含半胱氨酸。此外，在培养基中添加hevin改善了分化神经干细胞的神经突发芽和生长。与星形胶质细胞条件培养基相比，OEC 条件培养基中 hevin 的更高表达与更大的突触形成能力相关。因此，我们的结果表明 OECs 分泌的可溶性因子为神经修复提供了一个允许的环境，hevin 是促进神经突萌发和生长的关键分子之一。与星形胶质细胞条件培养基相比，OEC 条件培养基中 hevin 的更高表达与更大的突触形成能力相关。因此，我们的结果表明 OECs 分泌的可溶性因子为神经修复提供了一个允许的环境，hevin 是促进神经突萌发和生长的关键分子之一。与星形胶质细胞条件培养基相比，OEC 条件培养基中 hevin 的更高表达与更大的突触形成能力相关。因此，我们的结果表明 OECs 分泌的可溶性因子为神经修复提供了一个允许的环境，hevin 是促进神经突萌发和生长的关键分子之一。