Physiologic, ventilatory, and CNS transcriptomic response to chronic hypercapnia in goats

山羊对慢性高碳酸血症的生理、通气和中枢神经系统转录组反应

• 批准号: 10462046
• 负责人: Kirstyn Buchholz
• 金额: $ 3.82万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10462046
• 关键词: Acute; Adult; Affect; Air; Ambulatory Care Facilities; Animal Model; Animals; Bioinformatics; Biological Assay; Brain; Brain Stem; Breathing; Carbon Dioxide; Cell Nucleus; Chronic; Chronic Obstructive Pulmonary Disease; Data; Disease; Disease Progression; Dose; Exposure to; Financial compensation; Functional disorder; Gene Expression; Genes; Genome; Goals; Goat; Human Characteristics; Hypercapnia; Individual; Life; Lung; Lung diseases; Measures; Mechanics; Mediating; Modeling; Molecular; Molecular Biology Techniques; Neuronal Plasticity; Pathologic; Pathway Analysis; Pathway interactions; Patients; Persons; Phenotype; Physiological; Physiology; Predisposition; Preparation; Punch Biopsy; RNA; Rattus; Resistance; Respiratory Disease; Respiratory Failure; Risk Factors; Severities; Signal Pathway; Sinus; Stimulus; Symptoms; System; Techniques; Testing; Time; Tissue Extracts; Tissues; Training; blood pressure elevation; cDNA Library; cell type; cognitive function; cognitive system; comorbidity; differential expression; experience; experimental study; gene network; genome-wide; insight; mRNA sequencing; neurophysiology; novel; respiratory; response; transcriptome sequencing; transcriptomics

PROJECT SUMMARY Chronic obstructive pulmonary disease (COPD) affects 24 million US adults and over 1 billion people worldwide. COPD patients often present with chronic hypercapnia (CH, elevated CO2 in the body), with severity of CH increasing as the disease progresses. COPD is also marked by acute “attacks”, known as acute-on-chronic exacerbations, further increasing the level of hypercapnia within the body. Some COPD patients demonstrate tolerable, adaptive responses to the exacerbations, whereas others are prone to life-threatening severe hypercapnia and potentially fatal cardiorespiratory dysfunction. The severity of CH may be an important factor in setting the threshold of susceptibility to adaptive versus pathophysiologic responses. Indeed, our previous findings have shown goats chronically exposed to mild CH (6% inspired CO2, InCO2) demonstrated adaptations across multiple physiologic systems and tolerated further acute increases in InCO2 to 7 and 8% CO2. In contrast, in a preliminary study on one goat, chronically increasing InCO2 from mild to moderate levels (8% InCO2), resulted in pathophysiologic responses and the inability to compensate for acute further increases in InCO2 to 9% and 10%. The molecular underpinnings governing the protective/adaptive responses to chronic mild CH or pathophysiologic/maladaptive responses to chronic moderate CH are unclear. Accordingly, the overall goal of this proposal is to gain insight into CH-dependent molecular mechanisms which potentially underly both the protective/adaptive (AIM 1) and pathophysiologic/maladaptive physiologic (AIM 2) responses to increased CO2 challenges. For AIM 1 I will expose adult goats to 14 days (d) of room air (Group 1) or mild CH (Group 2). For AIM 2, I will expose goats to 7d of mild CH (6% CO2) followed by 7d of moderate CH (8% CO2) (Group 3). I will measure physiological/pathophysiologic responses across multiple physiologic systems during steady-state conditions and during acute CO2 challenges. Goats will be euthanized after these studies and I will extract tissue from key brainstem cardiorespiratory nuclei and utilize bulk-tissue mRNA sequencing (btRNA-Seq) to identify differentially expressed genes induced by both mild CH and moderate CH. I will use Ingenuity Pathway Analysis to identify canonical pathways and functional gene networks that are significantly altered during mild CH (6% CO2) alone, or 7d mild CH followed by 7d of moderate CH (8% CO2). Combining broad, unbiased techniques (btRNA-Seq) and physiologic studies will provide novel insights into the molecular mechanisms regulating cardiorespiratory control networks during CH. Further, results will yield information that will be critical in understanding the effect CH has on the physiologic dysfunction observed in outpatient clinics and ICUs. The training plan outlined in this proposal will provide me with the expertise needed to conduct physiologic experiments, molecular biology techniques, and bioinformatic analyses required for the proposed studies.

项目概要 慢性阻塞性肺病 (COPD) 影响着 2400 万美国成年人和全球超过 10 亿人。 COPD 患者常出现慢性高碳酸血症（CH，体内 CO2 升高），CH 的严重程度 随着病情的进展而增加。慢性阻塞性肺病还以急性“发作”为特征，称为慢性急性发作 恶化，进一步增加体内高碳酸血症的水平。一些慢性阻塞性肺病患者表现出 对恶化的耐受性、适应性反应，而其他人则容易出现危及生命的严重症状 高碳酸血症和潜在致命的心肺功能障碍。 CH 的严重程度可能是一个重要因素 设定对适应性反应与病理生理反应的敏感性阈值。确实，我们之前的 研究结果表明，长期暴露于轻度 CH（6% 吸入二氧化碳、InCO2）的山羊表现出了适应性 跨多个生理系统，并能耐受 InCO2 进一步急剧增加至 7% 和 8% CO2。相比之下， 在对一只山羊进行的初步研究中，长期将 InCO2 从轻度增加到中度水平（8% InCO2）， 导致病理生理反应并且无法补偿 InCO2 的进一步急剧增加 9%和10%。控制对慢性轻度 CH 或慢性轻度 CH 的保护性/适应性反应的分子基础 对慢性中度 CH 的病理生理/适应不良反应尚不清楚。据此，总体目标是 该提案旨在深入了解 CH 依赖性分子机制，该机制可能是 对 CO2 增加的保护性/适应性 (AIM 1) 和病理生理学/适应不良生理 (AIM 2) 反应 挑战。对于 AIM 1，我会将成年山羊暴露在室内空气（第 1 组）或温和的 CH（第 2 组）中 14 天 (d)。为了 目标 2，我将让山羊暴露在温和的 CH (6% CO2) 中 7 天，然后再暴露在中度 CH (8% CO2) 中 7 天（第 3 组）。我会 测量稳态期间多个生理系统的生理/病理生理反应 条件下以及在严重的二氧化碳挑战期间。这些研究结束后，山羊将被安乐死，我将提取组织 从关键脑干心肺核中提取，并利用大块组织 mRNA 测序 (btRNA-Seq) 来识别 轻度 CH 和中度 CH 诱导的差异表达基因。我将使用独创性路径分析 识别在轻度 CH 期间显着改变的典型途径和功能基因网络（6% 单独使用 CO2），或 7 天轻度 CH，然后 7 天中度 CH（8% CO2）。结合广泛、公正的技术 （btRNA-Seq）和生理学研究将为调节分子机制提供新的见解 CH 期间的心肺控制网络。此外，结果将产生对于以下方面至关重要的信息： 了解 CH 对门诊和 ICU 观察到的生理功能障碍的影响。这 本提案中概述的培训计划将为我提供进行生理学所需的专业知识 拟议研究所需的实验、分子生物学技术和生物信息分析。