Madhavan Lalitha, Freed William J, Anantharam Vellareddy, Kanthasamy Anumantha G
Parkinson's Disorder Research Laboratory, Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011-1250, USA.
J Pharmacol Exp Ther. 2003 Mar;304(3):913-23. doi: 10.1124/jpet.102.044370.
Apoptosis and glutamate-mediated excitotoxicity may play a role in the pathogenesis of many neurodegenerative disorders, including Parkinson's disease (PD). In the present study, we investigated whether stimulation of the 5-hydroxytryptamine 1A (5-HT1A) receptor attenuates N-methyl-D-aspartate- (NMDA) and 1-methyl-4-phenylpyridinium (MPP(+))-induced apoptotic cell death in cell culture models. A brief exposure (20 min) of M213-2O striatal cells to NMDA and glutamate produced a delayed increase in caspase-3 activity and DNA fragmentation in a dose- and time-dependent manner. NMDA-induced caspase-3 activity and DNA fragmentation were almost completely blocked by the 5-HT1A agonists 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) and (R)-5-fluoro-8 hydroxy-2-(dipropylamino)-tetralin (R-UH-301). Additionally, the protective effects of 8-OH-DPAT and R-UH-301 on NMDA-induced caspase-3 activation and apoptosis were reversed by pretreatment with the 5-HT1A antagonists N-[2-[4-(2-methoxyphenyl)-1-piperazinyl] ethyl]-N-(2-pyridinyl) cyclohexane carboxamide (WAY 100635) and S-UH-301, respectively. Similarly, dose- and time-dependent increases in caspase-3 activity and DNA fragmentation were observed in rat primary mesencephalic neurons after a brief exposure to NMDA and glutamate. Caspase-3 activation and DNA fragmentation in primary mesencephalic neurons were almost completely inhibited by 8-OH-DPAT. This neuroprotective effect of 8-OH-DPAT was reversed by WAY 100635. Additionally, 8-OH-DPAT blocked tyrosine hydroxylase (TH)-positive cell death after NMDA exposure and also almost completely attenuated the NMDA-induced Ca(2+) influx in primary mesencephalic cultures. Furthermore, 8-OH-DPAT and R-UH-301 blocked apoptotic cell death in the primary mesencephalic neurons that were exposed to the Parkinsonian toxin MPP(+). Together, these results suggest that 5-HT1A receptor stimulation may be a promising pharmacological approach in the development of neuroprotective agents for PD.
细胞凋亡和谷氨酸介导的兴奋毒性可能在包括帕金森病（PD）在内的许多神经退行性疾病的发病机制中起作用。在本研究中，我们调查了刺激5-羟色胺1A（5-HT1A）受体是否能减轻细胞培养模型中N-甲基-D-天冬氨酸（NMDA）和1-甲基-4-苯基吡啶鎓（MPP(+)）诱导的凋亡性细胞死亡。将M213-2O纹状体细胞短暂暴露（20分钟）于NMDA和谷氨酸后，半胱天冬酶-3活性和DNA片段化呈剂量和时间依赖性延迟增加。NMDA诱导的半胱天冬酶-3活性和DNA片段化几乎完全被5-HT1A激动剂8-羟基-2-（二正丙基氨基）四氢化萘（8-OH-DPAT）和（R）-5-氟-8-羟基-2-（二丙基氨基）四氢化萘（R-UH-301）阻断。此外，8-OH-DPAT和R-UH-301对NMDA诱导的半胱天冬酶-3激活和凋亡的保护作用分别被5-HT1A拮抗剂N-[2-[4-（2-甲氧基苯基）-1-哌嗪基]乙基]-N-（2-吡啶基）环己烷甲酰胺（WAY 100635）和S-UH-301预处理逆转。同样，将大鼠原代中脑神经元短暂暴露于NMDA和谷氨酸后，观察到半胱天冬酶-3活性和DNA片段化呈剂量和时间依赖性增加。8-OH-DPAT几乎完全抑制了原代中脑神经元中的半胱天冬酶-3激活和DNA片段化。WAY 100635逆转了8-OH-DPAT的这种神经保护作用。此外，8-OH-DPAT阻断了NMDA暴露后酪氨酸羟化酶（TH）阳性细胞的死亡，并且几乎完全减弱了原代中脑培养物中NMDA诱导的Ca(2+)内流。此外，8-OH-DPAT和R-UH-301阻断了暴露于帕金森毒素MPP(+)的原代中脑神经元中的凋亡性细胞死亡。总之，这些结果表明，刺激5-HT1A受体可能是开发用于PD的神经保护剂的一种有前景的药理学方法。
