Department of Neurosurgery, Eberhard-Karls-Univesity, Hoppe-Seyler-Str 3, 72076 Tübingen, Germany.
Exp Cell Res. 2010 Jan 15;316(2):216-31. doi: 10.1016/j.yexcr.2009.08.006. Epub 2009 Aug 15.
The ability of mesenchymal stem cells to generate functional neurons in culture is still a matter of controversy. In order to assess this issue, we performed a functional comparison between neuronal differentiation of human MSCs and fetal-derived neural stem cells (NSCs) based on morphological, immunocytochemical, and electrophysiological criteria. Furthermore, possible biochemical mechanisms involved in this process were presented. NF200 immunostaining was used to quantify the yield of differentiated cells after exposure to cAMP. The addition of a PKA inhibitor and Ca(2+) blockers to the differentiation medium significantly reduced the yield of differentiated cells. Activation of CREB was also observed on MSCs during maturation. Na(+)-, K(+)-, and Ca(2+)-voltage-dependent currents were recorded from MSCs-derived cells. In contrast, significantly larger Na(+) currents, firing activity, and spontaneous synaptic currents were recorded from NSCs. Our results indicate that the initial neuronal differentiation of MSCs is induced by cAMP and seems to be dependent upon Ca(2+) and the PKA pathway. However, compared to fetal neural stem cells, adult mesenchymal counterparts are limited in their neurogenic potential. Despite the similar yield of neuronal cells, NSCs achieved a more mature functional state. Description of the underlying mechanisms that govern MSCs' differentiation toward a stable neuronal phenotype and their limitations provides a unique opportunity to enhance our understanding of stem cell plasticity.
间充质干细胞在培养中生成功能性神经元的能力仍然存在争议。为了评估这个问题，我们基于形态学、免疫细胞化学和电生理学标准，对人骨髓间充质干细胞和胎源性神经干细胞（NSCs）的神经元分化进行了功能比较。此外，还提出了该过程中涉及的可能的生化机制。NF200 免疫染色用于定量 cAMP 暴露后分化细胞的产量。在分化培养基中加入 PKA 抑制剂和 Ca(2+) 阻断剂会显著降低分化细胞的产量。在成熟过程中还观察到 MSC 中 CREB 的激活。从 MSC 衍生的细胞中记录到 Na(+)-、K(+)-和 Ca(2+)-电压依赖性电流。相比之下，从 NSCs 中记录到的 Na(+)电流、放电活动和自发突触电流明显更大。我们的结果表明，MSC 的初始神经元分化是由 cAMP 诱导的，似乎依赖于 Ca(2+)和 PKA 途径。然而，与胎源性神经干细胞相比，成体间充质对应物的神经发生潜力有限。尽管神经元细胞的产量相似，但 NSCs 达到了更成熟的功能状态。描述支配 MSC 向稳定神经元表型分化的潜在机制及其局限性，为增强我们对干细胞可塑性的理解提供了独特的机会。
