Using dual intersectional genetics to understand and modulate itch

使用双重交叉遗传学来理解和调节瘙痒

• 批准号: 8634026
• 负责人: Sarah Elizabeth Ross
• 金额: $ 16.32万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8634026
• 关键词: Address; Alleles; American; Behavior; Behavioral; Cells; Chronic; Clinical; Clozapine; Coupled; Cre-LoxP; Environment; Esthesia; Genetic; Genetic Techniques; Glean; Goals; Health; In Vitro; Interneurons; Label; Ligands; Light; Link; Mediating; Molecular Genetics; Mus; Nervous system structure; Neurons; Organism; Oxides; Pharmacogenetics; Physiological; Population; Preparation; Property; Proteins; Pruritus; Public Health; Quality of life; Reflex action; Regulation; Reporter; Research; Role; Skin; Spinal; Spinal Cord; Spinal cord posterior horn; Surface; Synaptic Vesicles; System; Testing; Tetanus; Time; Toxin; Work; base; dorsal horn; effective therapy; hazard; improved; in vivo; inhibitory neuron; insight; neural circuit; novel; public health relevance; receptor; receptor coupling; recombinase; relating to nervous system; research study; response; therapeutic target; tool; transcription factor; transgene expression

DESCRIPTION (provided by applicant): Chronic itch (pruritis) is a widespread condition that severely diminishes quality of life. However, there are few effective treatments for chronic itch, in part because the neural basis for itch remains poorly understood. Thus, the long-term goal of our research is to gain a better understanding of how itch is encoded in the nervous system at the level of specific neural circuits with the view of developing more effective therapies for pruritis. We previously discovered that the transcription factor Bhlhb5 is required for the surviva of a subset of inhibitory interneurons in the spinal cord (which are here termed B5-I neurons) that are required for normal itch sensation; mice lacking these spinal interneurons suffer from persistent pathological itch. These findings imply that B5-I neurons function to inhibit itch; however, the evidence is merely correlative. In this application we propose to use intersectional genetic strategies to manipulate the activity of B5-I neurons in order to establish cause-and-effect relationships between the activity of B5-I neurons and scratching behavior in mice. Here we propose to test this hypothesis through 3 specific aims: 1) Characterize the Bhlhb5-flpO knockin mouse, a key tool for our dual intersection strategy, and use this mouse together with the Ptf1a-cre line to genetically define B5-I neurons. 2) Investigate the functional response properties of B5-I neurons to natural stimulation of the skin and to confirm the ability of pharmacogenetic approaches to specifically manipulate their activity. 3) Use exocytogenetic and pharmacogenetic approaches to delineate function of B5-I neurons in vivo for itch-mediated scratching behavior. Results from these experiments will begin decoding the neural circuits that underlie itch by enabling us to visualize, characterize, and functionally manipulate B5-I neurons in vitro and in vivo. Moreover, the insight gleaned may have major clinical implications for people that suffer from chronic itch.

描述（由申请人提供）：慢性瘙痒（瘙痒症）是一种普遍存在的疾病，严重降低生活质量。然而，慢性瘙痒的有效治疗方法很少，部分原因是人们对瘙痒的神经基础仍知之甚少。因此，我们研究的长期目标是更好地了解神经系统中特定神经回路水平上如何编码瘙痒，以开发更有效的瘙痒治疗方法。我们之前发现，转录因子 Bhlhb5 是脊髓中一部分抑制性中间神经元（此处称为 B5-I 神经元）存活所必需的，而这些神经元是正常瘙痒感所必需的；缺乏这些脊髓中间神经元的小鼠会遭受持续的病理性瘙痒。这些发现表明 B5-I 神经元具有抑制瘙痒的功能；然而，证据只是相关的。在本申请中，我们建议使用交叉遗传策略来操纵 B5-I 神经元的活动，以便建立 B5-I 神经元的活动与小鼠抓挠行为之间的因果关系。在这里，我们建议通过 3 个具体目标来检验这一假设：1) 表征 Bhlhb5-flpO 敲入小鼠，这是我们双交叉策略的关键工具，并使用该小鼠与 Ptf1a-cre 系一起从基因上定义 B5-I 神经元。 2) 研究 B5-I 神经元对皮肤自然刺激的功能反应特性，并确认药物遗传学方法特异性操纵其活性的能力。 3) 使用胞外遗传学和药物遗传学方法来描述体内 B5-I 神经元对瘙痒介导的抓挠行为的功能。这些实验的结果将使我们能够在体外和体内可视化、表征和功能性操纵 B5-I 神经元，从而开始解码瘙痒背后的神经回路。此外，收集到的见解可能对患有慢性瘙痒的人具有重大的临床意义。