Leptin signaling in the carotid body: mechanisms and consequences

颈动脉体中的瘦素信号传导：机制和后果

• 批准号: 10782846
• 负责人: Vsevolod Y Polotsky
• 金额: $ 63.46万
• 依托单位: GEORGE WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10782846
• 关键词: Acute; Address; Adipose tissue; Animals; Area; Attenuated; Award; Blood; Blood - brain barrier anatomy; Brain; Breathing; CISH gene; Cardiovascular system; Carotid Body; Cations; Cells; Chronic; Data; Denervation; Diabetes Mellitus; Disease; Epigenetic Process; Exposure to; Fatty acid glycerol esters; Formulation; Funding; Gene Expression; Glomus Cell; Glucose Clamp; Goals; Hormones; Human; Hydrogels; Hypercapnia; Hyperglycemia; Hyperinsulinism; Hypertension; Hypoxia; Injections; Ion Channel; JAK2 gene; Kidney; Leptin; Leptin deficiency; Leptin resistance; Link; Metabolism; Modeling; Molecular; Morbidity - disease rate; Mus; Nerve; Non-Insulin-Dependent Diabetes Mellitus; Obese Mice; Obesity; Obstructive Sleep Apnea; Oxygen; PIK3CG gene; Pathway interactions; Patients; Peripheral; Protein Isoforms; Reflex action; Regulation; Resistance; Rodent; Role; STAT3 gene; Signal Transduction; Site; Sleep; Sleep Apnea Syndromes; Somatotype; Stat3 protein; Structure of phrenic nerve; Sympathetic Nervous System; TRP channel; Techniques; Technology; Telemetry; Tissues; Type I Epithelial Receptor Cell; Viral Vector; cardiovascular health; carotid sinus; comorbidity; diet-induced obesity; experimental study; genetic manipulation; glucose metabolism; hypertension treatment; in vivo; intravenous glucose tolerance test; leptin receptor; molecular assembly/self assembly; mortality; novel; novel therapeutics; obese person; patch clamp; protein tyrosine phosphatase 1B; receptor; reduced food intake; respiratory; respiratory health; response; sensor; small hairpin RNA; therapeutic target; trait

Obesity causes multiple complications including hypertension, type 2 diabetes and sleep disordered breathing (SDB), which contribute to cardiovascular morbidity and mortality. Obesity and its complications are linked to increased activity of the sympathetic nervous system (SNS). The carotid bodies (CB) modulate afferent input to the SNS and have been identified as a potential therapeutic target. CB denervation abolished hypertension and hyperglycemia. The robust CB hypoxic chemoreflex has been implicated in respiratory instability and increased loop gain, one of the cardinal traits of SDB. Our long-term goal is to develop novel therapeutics, which will treat hypertension, diabetes and SDB in obesity by modulating the CB activity. During the first funding period of the award, we discovered a unique pathway by which adipose-tissue-produced hormone leptin acts in CB to increase the hypoxic chemoreflex and induce hypertension. Leptin interacts with the long isoform of leptin receptor, LEPRb, on CB type I cells to activate transient receptor potential melastatin 7 (TRPM7) cation channel. This mechanism increases carotid sinus nerve (CSN) activity and the chemoreflex, which ultimately leads to SDB, hypertension and perturbations of glucose metabolism. We developed novel molecular approaches to interrogate the CB leptin-TRPM7 pathway targeting Leprb gene expression, signaling via the JAK/STAT3 and PI3K and targeting leptin resistance induced by suppressor of cytokine signaling-3 (SOCS3) and protein tyrosine phosphatase 1B (PTP1B). The overarching hypothesis of this proposal is that, in DIO, leptin acts via TRPM7 in the CB type I cells to increase the hypoxic chemoreflex and CSN activity leading to SNS activation, hypertension, diabetes, and SDB, all of which can be treated by our novel TRPM7 blocker. We will examine the role of the leptin-TRPM7 axis in CB in obesity-induced hypertension, diabetes (Specific Aim 1) and SDB (Specific Aim 2) in mice with diet-induced obesity (DIO). We propose that leptin acts via CB TRPM7 to increase SNS activity inducing hypertension and hyperglycemia and to augment the chemoreflex causing SDB, which will be abolished by (A) Leprb shRNA and (B) Trpm7 shRNA applied to CB; (C) TRPM7 blocker FTY720 in a novel extended release formulation administered to the CB; and that (D) LEPRb blocker Allo-aca and TRPM7 blocker FTY720 administered to CB will decrease CSN, phrenic, splanchnic and renal sympathetic nerve activity. Specific Aim 3 will examine the cellular and molecular regulation of LEPRb-TRPM7 signaling in CB of DIO mice. We propose that in DIO, high leptin levels increase TRPM7 activity in CB glomus cells (A) acutely via JAK2/PI3K signaling; (B) chronically by increasing Leprb and Trpm7 gene expression via the JAK2/STAT3 pathway. We will employ state-of-the-art techniques including in vivo manipulation of gene expression in CB with viral vectors, FTY720 hydrogel molecular assembly, telemetry recording, sleep studies with quantified analysis of breathing, CB type I cell patch clamping and sympathetic nerve recording. Our translational proposal will identify potential novel treatment of hypertension, diabetes and SDB in obesity.

肥胖会导致多种并发症，包括高血压、2型糖尿病和睡眠呼吸障碍 (SDB)导致心血管疾病的发病率和死亡率。肥胖及其并发症与 交感神经系统（SNS）的活动增加。颈动脉体（CB）调节传入输入， SNS已被确定为潜在的治疗靶点。CB去神经可消除高血压， 高血糖症强大的CB低氧化学感受器反射与呼吸不稳定性有关，并且增加了呼吸不稳定性。 环路增益是SDB的主要特性之一。我们的长期目标是开发新的治疗方法， 通过调节CB活性治疗高血压、糖尿病和肥胖中的SDB。在第一次融资期间 在获奖期间，我们发现了一种独特的途径，通过这种途径，脂肪组织产生的激素瘦素作用于 CB增加缺氧化学反射并诱发高血压。瘦素与瘦素长亚型相互作用 受体，LEPRb，激活瞬时受体电位melastatin 7（TRPM 7）阳离子通道。 这种机制增加颈动脉窦神经（CSN）的活动和化学反射，最终导致 SDB、高血压和糖代谢紊乱。我们开发了新的分子方法， 询问靶向Leprb基因表达的CB瘦素-TRPM 7途径，通过JAK/STAT 3进行信号传导， PI 3 K与SOCS 3和蛋白酪氨酸诱导的靶向瘦素抵抗 磷酸酶1B（PTP 1B）。这个提议的首要假设是，在DIO中，瘦素通过 TRPM 7在CB I型细胞中增加低氧化学反射和CSN活性，导致SNS 激活，高血压，糖尿病和SDB，所有这些都可以通过我们的新型TRPM 7阻断剂治疗。 我们将研究瘦素-TRPM 7轴在CB中在肥胖诱导的高血压、糖尿病（特异性高血压）、糖尿病（特异性高血压）和糖尿病（特异性高血压）中的作用。 目的1）和SDB（特定目的2）在饮食诱导的肥胖（DIO）小鼠。我们认为瘦素通过CB发挥作用 TRPM 7增加SNS活性诱导高血压和高血糖症并增强化学反射 引起SDB，将通过（A）Lepr B shRNA和（B）施加到CB的Trpm 7 shRNA消除SDB;（C）TRPM 7 给予CB的新型缓释制剂中的阻断剂FTY 720;和（D）LEPRb阻断剂 给予CB的Allo-aca和TRPM 7阻断剂FTY 720将减少CSN、膈神经、内脏神经和肾神经 交感神经活动具体目标3将检查LEPRb-TRPM 7的细胞和分子调节 在DIO小鼠的CB中的信号传导。我们认为，在DIO中，高瘦素水平增加CB球中TRPM 7的活性， 细胞（A）通过JAK 2/PI 3 K信号传导急性地;（B）通过增加Lepr B和Trpm 7基因表达慢性地， JAK 2/STAT 3通路。我们将采用最先进的技术，包括体内基因操作， 用病毒载体在CB中表达，FTY 720水凝胶分子组装，遥测记录，睡眠研究 呼吸定量分析、CB I型细胞膜片钳和交感神经记录。我们 翻译建议将确定潜在的新的治疗高血压，糖尿病和SDB的肥胖。