Agonist stimulation of the serotonin1A receptor causes suppression of anoxia-induced apoptosis via mitogen-activated protein kinase in neuronal HN2-5 cells
Agonist stimulation of the serotonin1A receptor causes suppression of anoxia-induced apoptosis via mitogen-activated protein kinase in neuronal HN2-5 cells
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DOI：
10.1046/j.1471-4159.1999.721489.x
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发表时间：
1999-04-01
影响因子：
4.7
通讯作者：
Banerjee, P
中科院分区：
文献类型：
--
作者：
Adayev, T;El-Sherif, Y;Banerjee, P
先前的研究表明，刺激神经元抑制性受体，如5-羟色胺受体（5-HT1A-R），可引起n型Ca2+通道和n -甲基- d -天冬氨酸受体活性的衰减，从而保护神经元免受兴奋性毒性。本研究的目的是研究5-HT1A-R是否也偶联到另一种途径，即使在Ca2+通道缺乏的细胞中也最终抑制细胞凋亡。使用Ca2+通道缺乏的海马神经元来源细胞系（HN2-5），我们在这里证明了另一种途径负责5- ht1a - r介导的保护这些细胞免受缺氧引发的凋亡，通过脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）进行评估。在百日咳毒素存在的情况下，5-HT1A-R激动剂诱发的保护作用被消除，并且还需要磷酸化介导的丝裂原活化蛋白激酶（MAPK）的激活，正如MAPK激酶抑制剂PD98059而不是磷脂酰肌醇3-激酶（PI-3K）抑制剂wortmannin消除激动剂引发的神经元细胞的拯救所证明的那样。此外，激动剂刺激5-HT1A-R导致HN2-5细胞中缺氧刺激的caspase s样活性抑制60%，这种抑制被PD98059而不是wortmannin所消除。虽然激动剂刺激5-HT1A-R引起HN2-5细胞中PI-3K γ的激活，但我们的研究结果表明，这种PI-3K γ活性与5-HT1A-R促进的caspase活性调节和细胞凋亡抑制无关。因此，在神经元HN2-5细胞中，激动剂结合5-HT1A-R导致mapk介导的caspase 3样酶的抑制，并通过Ca2+通道非依赖性途径抑制缺氧诱导的凋亡60-70%。
Previous studies have indicated that stimulation of neuronal inhibitory receptors, such as the serotonin,, receptor (5-HT1A-R), could cause attenuation of the activity of both N-type Ca2+ channels and N-methyl-D-aspartic acid receptors, thus resulting in protection of neurons against excitotoxicity. The purpose of this study was to investigate if the 5-HT1A-R is also coupled to an alternative pathway that culminates in suppression of apoptosis even in cells that are deficient in Ca2+ channels. Using a hippocampal neuron-derived cell line (HN2-5) that is Ca2+ channel-deficient, we demonstrate here that an alternative pathway is responsible for 5-HT1A-R-mediated protection of these cells from anoxia-triggered apoptosis, assessed by deoxynucleotidyl-transferase-mediated dUTP nick end-labeling (TUNEL). The 5-HT1A-R agonist-evoked protection was eliminated in the presence of pertussis toxin and also required phosphoryfation-mediated activation of mitogen-activated protein kinase (MAPK), as evidenced by the elimination of the agonist-elicited rescue of neuronal cells by the MAPK kinase inhibitor PD98059 but not by the phosphatidylinositol 3-kinase (PI-3K) inhibitor wortmannin. Furthermore, agonist stimulation of the 5-HT1A-R caused a 60% inhibition of anoxia-stimulated caspase S-like activity in the HN2-5 cells, and this inhibition was abrogated by PD98059 but not by wortmannin. Although agonist stimulation of the 5-HT1A-R caused an activation of PI-3K gamma in HN2-5 cells, our results showed that this PI-3K gamma activity was not linked to the 5-HT1A-R-promoted regulation of caspase activity and suppression of apoptosis. Thus, in the neuronal HN2-5 cells, agonist binding to the 5-HT1A-R results in MAPK-mediated inhibition of a caspase 3-like enzyme and a 60-70% suppression of anoxia-induced apoptosis through a Ca2+ channel-independent pathway.