Differentiation of ionic currents in CNS progenitor cells: Dependence upon substrate attachment and epidermal growth factor
Differentiation of ionic currents in CNS progenitor cells: Dependence upon substrate attachment and epidermal growth factor
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DOI：
10.1006/exnr.1996.0130
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发表时间：
1996-08-01
影响因子：
5.3
通讯作者：
Reier, PJ
中科院分区：
文献类型：
--
作者：
Feldman, DH;Thinschmidt, JS;Reier, PJ
在补充有表皮生长因子（EGF）的限定培养基中从中枢神经系统（CNS）组织生长的多能祖细胞，当附着于合适的基质时，分化以表达神经和神经胶质组织化学标记物和形态。为了评估这些细胞的功能特征，通过全细胞膜片钳方法研究了从出生后大鼠前脑培养的祖细胞中电压门控Na+和K+电流（I-Na，I-K）的表达。将未分化的细胞从增殖的“球”中急性分离，并在将球接种到聚赖氨酸/层粘连蛋白处理的盖玻片上后1-25天研究分化的细胞。在用含K+的移液管记录的分化细胞中，58%的细胞同时检测到I-Na和I-K，11%的细胞单独检测到I-Na，19%的细胞单独检测到I-K。用内部Cs+（分离I-Na），在接种后1天内在一些细胞中观察到高达45 pA/pF的I-Na，随后I-Na范围高达150 pA/pF。总的来说，84%的细胞表达I-Na，平均为38 pA/pF. I-Na具有快速动力学，如在神经元中，但稳态失活曲线为强负，类似于神经胶质I-Na。内向尾电流敏感的[K+]（出），观察复极化后10毫秒的测试脉冲与内部Cs+，表明在82%的细胞中的K+通道的表达。与分化细胞中观察到的大量电流相反，在从球体急性解离的细胞的记录中检测到很少或没有I-Na或I-K尾电流。因此，在EGF的存在下，离子电流在通过附着到适当的基质诱导的分化期间早期发展。细胞切换从EGF到碱性成纤维细胞生长因子（bFGF）时，接种到盖玻片上显示大大减少的增殖和开发较少的神经元样形态比细胞接种在EGF的存在下。I-Na在bFGF处理的细胞中仅观察到53%，平均为9 pA/pF。因此，与bFGF促进某些CNS祖细胞群体神经元分化的报道相反，我们的EGF生成的出生后大鼠CNS祖细胞在切换到含有bFGF的培养基时不具有神经元特征。因此，分化的CNS祖细胞可以表达神经元和神经胶质分子、形态学和电生理学特性的混合物，这些特性可以通过培养条件进行修饰。(C)出版社：Academic Press，Inc.
Multipotential progenitor cells grown from central nervous system (CNS) tissues in defined media supplemented with epidermal growth factor (EGF), when attached to a suitable substratum, differentiate to express neural and glial histochemical markers and morphologies. To assess the functional characteristics of such cells, expression of voltage-gated Na+ and K+ currents (I-Na, I-K) was studied by whole-cell patch clamp methods in progenitors raised from postnatal rat forebrain, Undifferentiated cells were acutely dissociated from proliferative ''spheres,'' and differentiated cells were studied 1-25 days after plating spheres onto polylysine/laminin-treated coverslips. I-Na and I-K were detected together in 58%, I-Na alone in 11%, and I-K alone in 19% of differentiated cells recorded with K+-containing pipettes. With internal Cs+ (to isolate I-Na), I-Na up to 45 pA/pF was observed in some cells within 1 day after plating I-Na ranged up to 150 pA/pF subsequently. Overall, 84% of cells expressed I-Na, with an average of 38 pA/pF. I-Na had fast kinetics, as in neurons, but steady-state inactivation curves were strongly negative, resembling those of glial I-Na. Inward tail currents sensitive to [K+](out) were observed upon repolarization after the 10-ms test pulse with internal Cs+, indicating the expression of K+ channels in 82% of cells. In contrast to the substantial currents observed in differentiating cells, little or no I-Na or I-K-tail currents were detected in recordings from cells acutely dissociated from spheres. Thus, in the presence of EGF, ionic currents develop early during differentiation induced by attachment to an appropriate substratum. Cells switched from EGF to basic fibroblast growth factor (bFGF) when plated onto coverslips showed greatly reduced proliferation and developed less neuron-like morphologies than cells plated in the presence of EGF. I-Na was observed in only 53% of bFGF-treated cells, with an average of 9 pA/pF. Thus, in contrast to reports that bFGF promotes neuronal differentiation in some CNS progenitor populations, our EGF-generated postnatal rat CNS progenitors do not develop neuronal characteristics when switched to medium containing bFGF. Thus, differentiated CNS progenitors can express a mix of neuronal and glial molecular, morphological, and electrophysiological properties that can be modified by culture conditions. (C) 1996 Academic Press, Inc.