Effect of FGF-9 on cultured neurons : novel approach for the treatment of neurodegenerative disorders

我们研究了成纤维细胞生长因子（FGF）-9对大鼠基底前脑胆碱能神经元（BFCN）在胚胎第17天和前角胆碱能神经元（AHCN）获得胚胎第14天的原代培养的影响。FGF-9可增加BFCN和AHCN中AChE阳性神经元的存活率，增加其平均索马体积，并上调胆碱乙酰转移酶（ChAT）活性，其促进ChAT活性的作用与神经生长因子（NGF）相当，且强于碱性成纤维细胞生长因子（bFGF）、睫状神经营养因子（CNTF）和胶质源性神经营养因子（GDNF）。同时加入FGF-9和NGF诱导极高的ChAT水平，表明FGF-9和NGF可以通过不同的途径协同作用，增强BFCN中的胆碱能特性。在免疫细胞化学和原位杂交研究中培养的细胞，也在部分成年大鼠脑，BFCN显示细胞质免疫染色的FGF-9和表达的FGF-9信使RNA，因此，我们得出结论，FGF-9的行为BFCN自分泌和/或旁分泌的方式。因此，我们认为FGF-9可能是治疗阿尔茨海默病和肌萎缩侧索硬化症的一个有希望的候选药物，下一步是开发有效的方法将外源性FGF-9输送到中枢神经系统。我们将FGF-9与一些多胺偶联，这种FGF-9-多胺复合物可以通过体外BBB系统;然而，FGF-9与多胺偶联后对BFCN或AHCN的神经营养作用有所减弱。建立FGF-9-多胺偶联的最佳条件的实验现在正在进行中。

We examined the effect of fibroblast growth factor (FGF)-9 on primary cultures of rat basal forebrain cholinergic neurons (BFCN) obtained at embryonic day 17 and anterior horn cholinergic neurons (AHCN) obtained embryonic day 14. FGF-9 enhanced survival of AChE-positive neurons, increased their mean soma size, and upregulated choline their acetyltransferase (ChAT) activity in BFCN and AHCN.For BFCN, The ChAT-promoting effect of FGF-9 was approximately as potent as that of nerve growth factor (NGF) and was greater than those of basic fibroblast growth factor (bFGF), ciliary neurotrophic factor (CNTF), or glia-derived neurotrophic factor (GDNF). Simultaneous addition of FGF-9 and NGF induced extremely high ChAT levels, suggesting that FGF-9 and NGF may enhance cholinergic properties in BFCN via different pathways that can act synergistically. In immunocytochemical and in situ hybridization studies in cultured cells and also in sections of adult rat brain, BFCN showed cytoplasmic immunostaining for FGF-9 and expressed FGF-9 messenger RNA ; thus, we concluded that FGF-9 acts on BFCN in an autocrine and/or paracrine manner. Thus, we conclude that FGF-9 may be a promising candidate for therapeutic trials in Alzheimer disease and amyotrophic lateral sclerosis.The next step is to develop effective methods to deliver exogenous FGF-9 into the central nervous system. We coupled FGF-9 with some polyamines and this FGF-9-polyamine complex can pass through in vitro BBB system ; however, the neurotrophic effect of FGF-9 on BFCN or AHCN was somewhat diminished after coupling with polyamine. Experiments to establish optimal condition for FGF-9-polyamine coupling are now underway.