The influences of ghrelin on neural differentiation of adipose-derived mesenchymal stem cells (ASCs) were investigated in this study. The expression of typical neuronal markers, such as protein gene product 9.5 (PGP9.5) and Microtubule Associated Protein 2 (MAP2), as well as glial Fibrillary Acid Protein (GFAP) as a glial marker was evaluated in ASCs in different conditions. In particular, 2 µM ghrelin was added to control ASCs and to ASCs undergoing neural differentiation. For this purpose, ASCs were cultured in Conditioned Media obtained from Olfactory Ensheathing cells (OEC-CM) or from Schwann cells (SC-CM). Data on marker expression were gathered after 1 and 7 days of culture by fluorescence immunocytochemistry and flow cytometry. Results show that only weak effects were induced by the addition of only ghrelin. Instead, dynamic ghrelin-induced modifications were detected on the increased marker expression elicited by glial conditioned media. In fact, the combination of ghrelin and conditioned media consistently induced a further increase of PGP9.5 and MAP2 expression, especially after 7 days of treatment. The combination of ghrelin with SC-CM produced the most evident effects. Weak or no modifications were found on conditioned medium-induced GFAP increases. Observations on the ghrelin receptor indicate that its expression in control ASCs, virtually unchanged by the addition of only ghrelin, was considerably increased by CM treatment. These increases were enhanced by combining ghrelin and CM treatment, especially at 7 days. Overall, it can be assumed that ghrelin favors a neuronal rather than a glial ASC differentiation.

本研究探讨了生长素释放肽对脂肪间充质干细胞 (ASC) 神经分化的影响。在不同条件下在 ASC 中评估了典型神经元标记的表达，例如蛋白质基因产物 9.5 (PGP9.5) 和微管相关蛋白 2 (MAP2)，以及作为神经胶质标记的神经胶质纤维酸蛋白 (GFAP)。特别是，2 µM ghrelin 被添加到控制 ASCs 和进行神经分化的 ASCs。为此，在从嗅鞘细胞 (OEC-CM) 或雪旺细胞 (SC-CM) 获得的条件培养基中培养 ASC。在培养 1 天和 7 天后，通过荧光免疫细胞化学和流式细胞术收集有关标记表达的数据。结果表明仅添加生长素释放肽仅诱导微弱的作用。反而，在神经胶质条件培养基引起的标记表达增加上检测到动态生长素释放肽诱导的修饰。事实上，生长素释放肽和条件培养基的组合持续诱导 PGP9.5 和 MAP2 表达的进一步增加，尤其是在处理 7 天后。ghrelin 与 SC-CM 的组合产生了最明显的效果。在条件培养基诱导的 GFAP 增加上发现微弱或没有修饰。对生长素释放肽受体的观察表明，它在对照 ASC 中的表达，仅通过添加生长素释放肽几乎没有变化，而通过 CM 处理显着增加。这些增加通过结合生长素释放肽和 CM 治疗得到增强，尤其是在第 7 天。总的来说，可以假设 ghrelin 有利于神经元而不是神经胶质 ASC 分化。