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Differentiation. 2010 Nov-Dec;80(4-5):213-27. doi: 10.1016/j.diff.2010.07.001. Epub 2010 Sep 1.
Multipotent mesenchymal stromal cells raise great interest for regenerative medicine studies. Some MSC subpopulations have the potential to undergo neural differentiation, including marrow isolated adult multilineage inducible (MIAMI) cells, which differentiate into neuron-like cells in a multi-step neurotrophin 3-dependent manner. Epidermal and basic fibroblast growth factors are often used in neuronal differentiation protocols for MSCs, but with a limited understanding of their role. In this study, we thoroughly assessed for the first time the capacity of these factors to enhance the neuronal differentiation of MSCs.
We have characterized MIAMI cell neuronal differentiation program in terms of stem cell molecule expression, cell cycle modifications, acquisition of a neuronal morphology and expression of neural and neuronal molecules in the absence and presence of an EGF-bFGF pre-treatment.
EGF-bFGF pre-treatment down-regulated the expression of stemness markers Oct4A, Notch1 and Hes5, whereas neural/neuronal molecules Nestin, Pax6, Ngn2 and the neurotrophin receptor tyrosine kinase 1 and 3 were up-regulated. During differentiation, a sustained Erk phosphorylation in response to NT3 was observed, cells began to exit from the cell cycle and exhibit increased neurite-like extensions. In addition, neuronal β3-tubulin and neurofilament expression was increased; an effect mediated via the Erk pathway. A slight pre-oligodendrocyte engagement was noted, and no default neurotransmitter phenotype was observed. Overall, mesodermal markers were unaffected or decreased, while neurogenic/adipogenic PPARγ2 was increased.
EGF and bFGF pre-treatment enhances neural specification and the response to neuronal commitment of MIAMI cells, further increasing their potential use in adult cell therapy of the nervous system.
多能间充质基质细胞引起了再生医学研究的极大兴趣。一些 MSC 亚群具有潜在的神经分化能力，包括骨髓分离的成年多谱系诱导（MIAMI）细胞，这些细胞以多步神经营养因子 3 依赖的方式分化为神经元样细胞。表皮和碱性成纤维细胞生长因子通常用于 MSC 的神经元分化方案，但对其作用的了解有限。在这项研究中，我们首次全面评估了这些因子增强 MSC 神经分化能力的潜力。
我们根据干细胞分子表达、细胞周期修饰、获得神经元形态以及在不存在和存在 EGF-bFGF 预处理的情况下表达神经和神经元分子，对 MIAMI 细胞的神经元分化程序进行了特征描述。
EGF-bFGF 预处理下调了干性标志物 Oct4A、Notch1 和 Hes5 的表达，而上调了神经/神经元分子 Nestin、Pax6、Ngn2 和神经生长因子受体酪氨酸激酶 1 和 3 的表达。在分化过程中，观察到持续的 Erk 磷酸化对 NT3 的反应，细胞开始退出细胞周期并表现出增加的神经突样延伸。此外，神经元 β3-微管蛋白和神经丝表达增加；这种效应是通过 Erk 途径介导的。注意到轻微的前少突胶质细胞参与，并且没有观察到默认的神经递质表型。总体而言，中胚层标志物不受影响或减少，而神经发生/脂肪生成 PPARγ2 增加。
EGF 和 bFGF 预处理增强了 MIAMI 细胞的神经特化和对神经元承诺的反应，进一步增加了它们在成人神经系统细胞治疗中的潜在用途。
