Neurotrophins differentially enhance acetylcholine release, acetylcholine content and choline acetyltransferase activity in basal forebrain neurons
Neurotrophins differentially enhance acetylcholine release, acetylcholine content and choline acetyltransferase activity in basal forebrain neurons
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DOI：
10.1046/j.1471-4159.2001.00234.x
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发表时间：
2001-04-01
影响因子：
4.7
通讯作者：
Quirion, R
中科院分区：
文献类型：
--
作者：
Auld, DS;Mennicken, F;Quirion, R
多项证据表明，神经生长因子对基底前脑胆碱能表型的发育和维持起着重要作用，本研究利用大鼠原代胚胎基底前脑培养，证明了神经生长因子对功能性胆碱能标志物的差异调节作用（24-96 h）。治疗96小时后，神经生长因子（1-100 ng/mL）增加了胆碱乙酰转移酶活性（对照组的168-339%），乙酰胆碱含量（141-185%），以及组成（148-283%）和K+刺激（162-399%）乙酰胆碱释放，但释放增加并不伴随着高亲和力胆碱摄取增加。乙酰胆碱释放的增强作用在vesamicol （1 muM）的作用下减弱，提示乙酰胆碱的释放可能来自水泡，在无胆碱的条件下被消除，这强调了细胞外胆碱作为乙酰胆碱合成释放的主要来源的重要性。与未使用神经生长因子的培养物相比，神经生长因子处理的培养物释放的乙酰胆碱比例更大，被电压门控的Ca2+通道拮抗剂阻断，这表明神经生长因子改变了神经递质释放的这一参数。NGF （20 ng/mL）与K252a （200 nM）共处理可消除ChAT活性的增加，并阻止K+刺激的ACh释放增强，超过与K252a相关的水平，提示参与TrkA受体信号传导。此外，神经营养因子-3，神经营养因子-4和脑源性神经营养因子（均为5-200:ng/mL）增加乙酰胆碱释放，尽管它们不如神经生长因子有效，并且需要更高的浓度。然而，高脑源性神经营养因子浓度（100和200 ng/mL）确实将释放增加到与神经生长因子相似的水平，总之，基底前脑胆碱能神经元长期暴露于神经生长因子（天），以及以较弱的方式暴露于其他神经营养因子，增强了乙酰胆碱的释放，这取决于囊泡池和细胞外胆碱的可用性。
Several lines of evidence indicate that nerve growth factor is important for the development and maintenance of the basal forebrain cholinergic phenotype, in the present study, using rat primary embryonic basal forebrain cultures, we demonstrate the differential regulation of functional cholinergic markers by nerve growth factor treatment (24-96 h). Following a 96-h treatment, nerve growth factor (1-100 ng/mL) increased choline acetyltransferase activity (168-339% of control), acetylcholine content (141-185%), as well as constitutive (148-283%) and K+-stimulated (162-399%) acetylcholine release, but increased release was not accompanied by increased high-affinity choline uptake. Enhancement of ACh release was attenuated by vesamicol (1 muM), suggesting a vesicular source, and was abolished under choline-free conditions, emphasizing the importance of extracellular choline as the primary source for acetylcholine synthesized for release. A greater proportion of acetylcholine released from nerve growth factor-treated cultures than from nerve growth factor-naive cultures was blocked by voltage-gated Ca2+ channel antagonists, suggesting that nerve growth factor modified this parameter of neurotransmitter release. Cotreatment of NGF (20 ng/mL) with K252a (200 nM) abolished increases in ChAT activity and prevented enhancement of K+-stimulated ACh release beyond the level associated with K252a, suggesting the involvement of TrkA receptor signaling. Also, neurotrophin-3, neurotrophin-4 and brain-derived neurotrophic factor (all at 5-200:ng/mL) increased acetylcholine release, although they were not as potent as nerve growth factor and higher concentrations were required. High brain-derived neurotrophic factor concentrations (100 and 200 ng/mL) did, however, increase release to a level similar to nerve growth factor, in summary, long-term exposure (days) of basal forebrain cholinergic neurons to nerve growth factor, and in a less-potent fashion the other neurotrophins, enhanced the release of acetylcholine, which was dependent upon a vesicular pool and the availability of extracellular choline.