Endogenous Opioid Mechanisms Modulating Stress

内源性阿片类药物调节压力的机制

• 批准号: 6723870
• 负责人: Jay P. McLaughlin
• 金额: $ 7.86万
• 依托单位: NORTHEASTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6723870
• 关键词: analgesia; behavioral /social science research tag; brain mapping; chemical structure function; confocal scanning microscopy; coping; endorphins; gene expression; genetically modified animals; immunocytochemistry; intermolecular interaction; laboratory mouse; molecular psychobiology; neural information processing; neurogenetics; neuropsychological tests; neuroregulation; opioid receptor; phosphorylation; posttranslational modifications; psychopharmacology; stress

DESCRIPTION (provided by applicant): Endogenous opioid peptides are believed to modulate the physiological response to stress, regulating pain sensation, reward pathways and behavioral responses to the environment. This proposal will assess the mediating role of the endogenous kappa opioid system in responses to a mild stressor, the forced swim test. Mice will be exposed to forced swimming to induce the release of endogenous opioid peptides known to activate kappa opioid receptors. Initial results show that the mild stress induced by repeated forced swim testing increased behavioral immobility and subsequent tail flick latency through a mechanism sensitive to the kappa opioid antagonist, nor-BNI or dynorphin gene disruption. Further assessment of the endogenous activation of kappa opioid receptors is possible with a novel antibody probe (KOR-P) that can distinguish the agonist-activated form of the receptor. When opioid receptors are activated by applied agonist or endogenously released opioid peptide, G-protein receptor kinase phosphorylates the serine-369 residue on the kappa opioid receptor to initiate the desensitization process. Preliminary data suggest that the KOR-P antibody can distinguish the phosphorylated kappa opioid receptor from the basal state, and thus may be used as a probe in Western blot and immunocytochemical analyses to detect prior activation of the kappa opioid system. Pilot Western blot results demonstrate that the forced-swim stress induced an increase in KOR-P antibody labeling of brain protein isolated from tested mice. The increase in specific labeling was blocked by administration of nor-BNI prior to swim testing. Future studies are planned to determine the endogenous opioid peptides that are producing the kappa opioid receptor activation in response to the swim stressor, starting with examination of dynorphin knockout mice and their wild-type littermates in the forced swim test. In addition, studies will be extended to refine immunocytochemical methods and determine where in the brain kappa opioid receptor activation occurs in response to environmental stress. It is expected that this data set would define a functional neural circuit activated by behavioral stress and regulated by the action of the endogenous kappa opioid system. A better understanding of the relationship between stress and endogenous kappa systems may lead to new insights into such disorders as depression and relapse of drug abuse, possibly providing new therapeutic approaches in these syndromes.

描述（由申请人提供）：内源性阿片肽被认为可以调节对压力的生理反应，调节疼痛感、奖赏途径和对环境的行为反应。该提案将评估内源性卡帕阿片类药物系统在应对轻度压力源（强迫游泳测试）时的调节作用。 小鼠将被迫游泳，以诱导内源性阿片肽的释放，已知该肽可激活κ阿片受体。初步结果表明，重复强迫游泳测试引起的轻微压力通过对 kappa 阿片拮抗剂、去甲 BNI 或强啡肽基因破坏敏感的机制增加了行为不动性和随后的甩尾潜伏期。使用新型抗体探针 (KOR-P) 可以进一步评估 kappa 阿片受体的内源性激活，该探针可以区分受体的激动剂激活形式。当阿片受体被应用的激动剂或内源释放的阿片肽激活时，G 蛋白受体激酶磷酸化 kappa 阿片受体上的丝氨酸 369 残基以启动脱敏过程。初步数据表明，KOR-P 抗体可以区分磷酸化的 kappa 阿片受体与基础状态，因此可用作蛋白质印迹和免疫细胞化学分析中的探针，以检测 kappa 阿片系统的先前激活。初步蛋白质印迹结果表明，强迫游泳压力会导致从测试小鼠中分离出的脑蛋白中 KOR-P 抗体标记的增加。在游泳测试之前施用去甲 BNI 可以阻止特异性标记的增加。未来的研究计划确定内源性阿片肽，这些肽在游泳应激源下产生卡帕阿片受体激活，首先在强迫游泳测试中检查强啡肽敲除小鼠及其野生型同窝小鼠。此外，研究将扩大到完善免疫细胞化学方法，并确定大脑中卡帕阿片受体激活的位置以响应环境压力。预计该数据集将定义由行为压力激活并由内源性卡帕阿片类药物系统的作用调节的功能性神经回路。更好地理解压力和内源性卡帕系统之间的关系可能会给抑郁症和药物滥用复发等疾病带来新的见解，并可能为这些综合征提供新的治疗方法。