Nicotine activates the extracellular signal-regulated kinase 1/2 via the α7 nicotinic acetylcholine receptor and protein kinase A, in SH-SY5Y cells and hippocampal neurones
Nicotine activates the extracellular signal-regulated kinase 1/2 via the α7 nicotinic acetylcholine receptor and protein kinase A, in SH-SY5Y cells and hippocampal neurones
复制标题
DOI：
10.1046/j.0022-3042.2001.00725.x
复制
发表时间：
2002-02-01
影响因子：
4.7
通讯作者：
Wonnacott, S
中科院分区：
文献类型：
--
作者：
Dajas-Bailador, FA;Soliakov, L;Wonnacott, S
神经元烟碱乙酰胆碱受体（nAChR）可以调节许多细胞机制，如细胞存活和记忆处理，这些机制也受到丝氨酸/苏氨酸蛋白激酶ERK 1/2的影响。在SH-SY 5 Y细胞和海马神经元中，尼古丁（100 μ m）增加了ERK 1/2的活性。这种作用是Ca 2+依赖性的，并且被α 7 nAChR拮抗剂α-银环蛇毒素（α-Bgt）和上游激酶MEK的抑制剂（PD 98059）阻止。为了确定连接Ca 2+进入MEK-ERK 1/2激活的干预步骤，使用了Ca 2+依赖性激酶的抑制剂。在SH-SY 5 Y细胞中，PKC（Ro 31-8220）、CaM激酶II（KN-62）或P13激酶（LY 294002）的选择性阻断剂未能抑制尼古丁诱发的ERK 1/2活性的增加。相反，两种结构不同的PKA抑制剂（KT 5720和H-89）完全阻止了ERK 1/2活性的尼古丁依赖性增加。在海马培养物中也观察到H-89对尼古丁诱发的ERK 1/2活性增加的抑制。PKA下游，B-Raf的活性显着降低尼古丁在SH-SY 5 Y细胞中，通过直接测量MEK 1磷酸化或体外激酶测定，而由Raf-1的MEK 1磷酸化的调制倾向于增加。因此，这项研究提供了一种新的信号通路耦合刺激的α 7 nAChR的ERK 1/2的激活，在钙离子和PKA依赖的方式的证据。
Neuronal nicotinic acetylcholine receptors (nAChR) can modulate many cellular mechanisms, such as cell survival and memory processing, which are also influenced by the serine/ threonine protein kinases ERK1/2. In SH-SY5Y cells and hippocampal neurones, nicotine (100 mum) increased the activity of ERK1/2. This effect was Ca2+ dependent, and prevented by the alpha7 nAChR antagonist alpha-bungarotoxin (alpha-Bgt) and an inhibitor (PD98059) of the upstream kinase MEK. To determine the intervening steps linking Ca2+ entry to MEK-ERK1/2 activation, inhibitors of Ca2+-dependent kinases were deployed. In SH-SY5Y cells, selective blockers for PKC (Ro 31-8220), CaM kinase II (KN-62) or P13 kinase (LY 294002) failed to inhibit the nicotine-evoked increase in ERK1/2 activity. In contrast, two structurally different inhibitors of PKA (KT 5720 and H-89) completely prevented the nicotine-dependent increase in ERK1/2 activity. Inhibition of the nicotine-evoked increase in ERK1/2 activity by H-89 was also observed in hippocampal cultures. Down stream of PKA, the activity of B-Raf was significantly decreased by nicotine in SH-SY5Y cells, as determined by direct measurement of MEK1 phosphorylation or in vitro kinase assays, whereas the modulation of MEK1 phosphorylation by Raf-1 tended to increase. Thus, this study provides evidence for a novel signalling route coupling the stimulation of alpha7 nAChR to the activation of ERK1/2, in a Ca2+ and PKA dependent manner.