The trophic requirements of mature motoneurons
The trophic requirements of mature motoneurons
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DOI：
10.1016/s0006-8993(98)00028-6
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发表时间：
1998-04-13
期刊：
影响因子：
2.9
通讯作者：
McLennan, IS
中科院分区：
文献类型：
--
作者：
Oorschot, DE;McLennan, IS
成熟的运动神经元与许多细胞类型相互作用，包括骨骼肌纤维、雪旺细胞、神经胶质和各种神经元。这些细胞类型中的每一种都被认为为运动神经元提供营养支持，但不知道一种细胞类型提供的支持是否可以完全取代另一种细胞类型信号的缺失。已经使用体内模型研究了各种生长因子在没有肌纤维、雪旺细胞或长轴突突触输入的情况下支持运动神经元的能力。然而，这些研究并没有确定运动神经元的总需求，因为局部脊髓影响尚未消除。在本文中，总的营养需求的成熟运动神经元进行了评估，在低细胞密度培养，在所有其他类型的细胞的情况下。在这些条件下，成熟的运动神经元在24小时内通过细胞凋亡死亡，这相当于体外未成熟运动神经元死亡的速率。这与成熟细胞为凋亡做好准备的新兴观点一致。九种假定的营养因子（BDNF、CNTF、FGF 2、GDNF、IGF I、IGF II、NT 3、NT 4、TGF-β 2），无论是单独还是组合，都不能防止培养的运动神经元的快速死亡，即使这些因子中的一些能够减弱不太严重的损伤如轴突切断或撕脱的影响。因此，成熟运动神经元的存活可能依赖于生长因子的组合，其中至少一种因子与上述因子不同。(C)1998年Elsevier Science B.V.
Mature motoneurons interact with many cell types, including skeletal muscle fibres, Schwann cells, glia and various neurons. Each of these cell types is thought to provide trophic support to motoneurons, but it is not known whether the support provided by one cell type can fully substitute for the absence of a signal from another cell type. The ability of various growth factors to support motoneurons in the absence of muscle fibres, Schwann cells or long-axon synaptic input has been studied using in vivo models. However, these studies do not define the total needs of motoneurons, as local spinal influences have not been removed. In this paper, the total trophic requirement of mature motoneurons was assessed by culturing them at a low cell density, in the absence of all other cell types. Under these conditions, mature motoneurons die by apoptosis within 24 h, which is equivalent to the rate at which immature motoneurons die in vitro. This is consistent with the emerging view that mature cells are primed for apoptosis. Nine putative trophic factors (BDNF, CNTF, FGF2, GDNF, IGF I, IGF II, NT3, NT4, TGF-beta 2), either alone or in combination, were unable to prevent the rapid death of the cultured motoneurons, even though some of these factors are able to attenuate the affects of less severe injuries such as axotomy or avulsion. The survival of mature motoneurons may therefore be dependent on a combination of growth factors, with at least one of the factors being distinct from the above mentioned factors. (C) 1998 Elsevier Science B.V.