DOPAMINE-INDUCED NEUROTOXICITY IN A CATECHOLAMINERGIC CELL LINE

儿茶酚胺能细胞系中多巴胺诱导的神经毒性

• 批准号: 2578795
• 负责人: J M MASSERANO
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF MENTAL HEALTH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2578795
• 关键词: apoptosis; catalase; catecholamines; clone cells; cytotoxicity; dopamine; flow cytometry; gel electrophoresis; neural degeneration; neuropharmacology; neurotoxins; norepinephrine; schizophrenia

Overactive dopaminergic neurons in the brain are thought to play an important role in the etiology of schizophrenia. It has been hypothesized that prolonged exposure of catecholamine neurons to excessive levels of dopamine or the oxidative metabolites of dopamine may produce neuronal damage, cell death, and be partially responsible for some of the negative symptoms of schizophrenia. Catecholamines have been shown to be neurotoxic to norepinephrine and dopamine neurons in primary culture (J Neurosci Res 26:428, 1990; J Pharmacol Exp Ther 262:1274, 1992). We are evaluating the neurotoxic effects of dopamine by using a clonal cell line developed by Chikaraishi and co-workers (J Neurosci 13:1280, 1993). This cell line was derived from a tyrosine hydroxylase positive tumor obtained from the CNS of transgenic mice carrying the SV 40 T antigen oncogene under the transcriptional control of the rat tyrosine hydroxylase gene. We found that incubation of CATH.a cells with dopamine produced a time and dose dependent increase in cell death. Cell death also occurred after treatment with the catecholamines, l-dihydroxy- phenylalanine, norepinephrine, epinephrine, and isoparoterenol, as well as the neurotoxic compound, 6-hydroxydopamine. Cell death did not appear to be receptor mediated, since selective noradrenergic and dopaminergic receptor agonists had no effect on CATH.a cell viability. Dopamine induces apoptotic cell death as indicated by DNA fragmentation measured by gel electrophoresis and by flow cytometric analysis. Apoptosis appears to be produced by dopamine autoxidation, since intracellular peroxides increase after dopamine treatment and cell death can be inhibited by catalase and n-acetylcysteine. N-acetylcysteine produced a dose dependent (100-1250 mM) decrease in dopamine-induced cell death and this correlated with a decrease in peroxide formation. In addition, antisense to the antioxidant protein, Bcl-2, increases the sensitivity of CATH.a cells to dopamine induced cell death. These findings indicate that the oxidative products of dopamine cause neurotoxicity through apoptosis.

大脑中过度活跃的多巴胺能神经元被认为是 在精神分裂症病因学中的重要作用。 已经 假设，长期暴露于儿茶酚胺神经元， 过量的多巴胺或多巴胺的氧化代谢物可 产生神经元损伤，细胞死亡，并部分负责 精神分裂症的一些负面症状 儿茶酚胺已经被 显示对原发性肾上腺素和多巴胺神经元具有神经毒性 培养（J Neurosci Res 26：428，1990; J Pharmacol Exp Ther 262：1274， 1992年）。 我们正在评估多巴胺的神经毒性作用， Chikaraishi及其同事开发的克隆细胞系（J Neurosci 13：1280，1993）。 该细胞系来源于酪氨酸羟化酶 从携带SV的转基因小鼠的CNS获得的阳性肿瘤 大鼠40 T抗原癌基因的转录调控 酪氨酸羟化酶基因 我们发现，将CATH. a细胞与 多巴胺引起细胞死亡的时间和剂量依赖性增加。 细胞 在用儿茶酚胺、L-二羟基- 苯丙氨酸、去甲肾上腺素、肾上腺素和异丙肾上腺素， 神经毒性化合物6-羟基多巴胺 未出现细胞死亡 受体介导，因为选择性去甲肾上腺素能和多巴胺能 受体激动剂对CATH. a细胞活力没有影响。 多巴胺 诱导凋亡性细胞死亡，如测量的DNA片段化所示 通过凝胶电泳和流式细胞术分析。 凋亡 似乎是由多巴胺自氧化产生的，因为细胞内 多巴胺处理后过氧化物增加， 被过氧化氢酶和N-乙酰半胱氨酸抑制。 N-乙酰半胱氨酸产生 多巴胺诱导的细胞死亡的剂量依赖性（100-1250 mM）降低 并且这与过氧化物形成的减少相关。 此外，本发明还提供了一种方法， 抗氧化蛋白Bcl-2的反义增加了敏感性 CATH. a细胞对多巴胺诱导的细胞死亡的反应。 这些发现表明 多巴胺的氧化产物通过 凋亡