CELLULAR RESPONSES TO HALLUCINOGENS

细胞对致幻剂的反应

• 批准号: 6295004
• 负责人: STUART C. SEALFON
• 金额: $ 21.45万
• 依托单位: MOUNT SINAI SCHOOL OF MEDICINE OF CUNY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6295004
• 关键词: G protein; cerebral cortex; conformation; drug receptors; genetically modified animals; hallucinogens; laboratory mouse; pharmacokinetics; protein structure function; psychopharmacology; receptor binding; receptor coupling; receptor expression; receptor sensitivity; serotonin receptor

Hallucinogenic drugs of abuse are partial agonists at the serotonin 5- HT2A receptor. The molecular mechanisms mediating their hallucinogenic potential are not known. Utilizing the understanding about hallucinogen interactions with the H-HT/2A receptor that we have developed from our previous inter-disciplinary work in an IRPG, we propose to study the specific conformational effects induced by hallucinogenic and non-hallucinogenic serotonergic agonists acting at the 5-HT2A receptor. Agonist binding to a receptor stabilizes the protein in a particular relative distribution of conformations. Each conformational state has a propensity to interact with specific G-proteins, inducing second messenger responses and activation of endogenous genes, and with regulatory proteins, leading to phosphorylation, internalization, and desensitization. These downstream effects will be assayed as reflections on the conformational stages stabilized by a particular agonist. Full and partial 5-HT/2A agonists that differ in their hallucinogenic potential will be studied and the basis for differences in the responses observed will be investigated. Mutations of the H-HT2A receptor that modify relative agonist positioning and efficacy, relative G-protein activation, and stability of the inactive stage have been identified and their effects on the responses elicited in cell lines by different hallucinogens and non- hallucinogens will be determined. In order to assay cellular responses both in cell lines and in neurons in vivo, we will assay intrinsic reporters of cellular signaling (IRC) that manifest rapid alterations in response to signal transduction activation. IRC responses to hallucinogens and non- hallucinogens will be measured in cortical neurons in knock-in mice expressing the human wild-type and mutant receptors in place of the endogenous receptor. These studies will provide insight into the molecular basis for the cellular responses to hallucinogenic chemicals elicited at the 5-HT/2A receptor and may facilitate the development of new therapeutic modalities.

滥用的致幻药物是5-羟色胺5-HT 2A受体的部分激动剂。介导其致幻潜力的分子机制尚不清楚。利用我们以前在IRPG中的跨学科工作中开发的关于致幻剂与H-HT/2A受体相互作用的理解，我们建议研究致幻和非致幻的多巴胺能受体激动剂作用于5-HT 2A受体引起的特定构象效应。激动剂与受体的结合使蛋白质稳定在特定的相对构象分布中。 每种构象状态都倾向于与特定的G蛋白相互作用，诱导第二信使反应和内源性基因的激活，并与调节蛋白相互作用，导致磷酸化，内化和脱敏。这些下游效应将作为对特定激动剂稳定的构象阶段的反映进行测定。将研究致幻潜力不同的完全和部分5-HT/2A激动剂，并研究观察到的反应差异的基础。已经鉴定了改变相对激动剂定位和功效、相对G蛋白活化和非活性阶段稳定性的H-HT 2A受体突变，并且将确定它们对不同致幻剂和非致幻剂在细胞系中引起的应答的影响。为了在体内测定细胞系和神经元中的细胞应答，我们将测定细胞信号传导（IRC）的内在报告分子，其表现出响应于信号转导激活的快速变化。将在表达人野生型和突变型受体代替内源性受体的敲入小鼠的皮质神经元中测量对致幻剂和非致幻剂的IRC反应。这些研究将提供深入了解致幻化学物质引起的5-HT/2A受体的细胞反应的分子基础，并可能促进新的治疗方式的发展。