Functional Analysis of Carotid Body Responses to Hypoxia in Mice"

小鼠颈动脉体对缺氧反应的功能分析"

• 批准号: 8133671
• 负责人: Luis E Pichard
• 金额: $ 3.69万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-06-11
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8133671
• 关键词: Animals; Beryllium; Brain Stem; Calcium; Canis familiaris; Cardiopulmonary; Carotid Body; Cell Hypoxia; Cell physiology; Cells; Characteristics; Chemoreceptors; Chronic; Complement; Cranial Nerves; Disease; Essential Hypertension; Felis catus; Fiber; Genetic; Genetic Predisposition to Disease; Genome; Glomus Cell; Goat; Health; Heart failure; High Pressure Liquid Chromatography; Homeostasis; Human; Hypoxia; Image; In Vitro; Inbreeding; Investigation; Journals; Knockout Mice; Link; Mammals; Measures; Methodology; Methods; Modality; Modeling; Molecular Target; Mouse Strains; Mus; Nerve; Neurobiology; Nucleus solitarius; Output; Oxygen; Patch-Clamp Techniques; Pilot Projects; Play; Publishing; Rattus; Reflex action; Research; Respiratory Center; Respiratory physiology; Rodent; Role; Sensory; Sleep Apnea Syndromes; Stream; Sudden infant death syndrome; Techniques; Type I Epithelial Receptor Cell; Whole Body Plethysmography; Work; afferent nerve; carotid sinus; congenital central hypoventilation syndrome; in vitro activity; in vivo; large-conductance calcium-activated potassium channels; mouse model; neurotransmitter release; relating to nervous system; response; tool; trend

DESCRIPTION (provided by applicant): The carotid body's role in sensing hypoxia is well established. It has also been implicated in several human health disorders such as SIDS, Sleep Apnea, Congenital Central Hypoventilation Syndrome, chronic heart failure and primary hypertension. Furthermore, these disorders have been strongly linked to a genetic predisposition. In order to study genetically linked disorders, an inbred or genetically manipulated mouse model is an ideal tool for investigation. In response to hypoxia, the carotid body activates respiratory centers via increasing the carotid chemoreceptor afferent nerve output. Thus, the most direct method for studying the overall carotid body's function is measuring the afferent carotid sinus nerve activity. Such studies have been done mostly in large animals. Although several studies have recorded mouse carotid sinus nerve activity in vitro, its characteristics are still not well described. Needless to say, studies in vivo using inbred or genetically manipulated mice are required in order to directly link genetics with altered carotid body function and human health disorders. The long term objective of my research is to study the role that genetics play in modulating carotid body function and carotid body-related human health disorders. For this application, I shall bridge in vivo assessment of the carotid body function and one molecular target, BK channels. BK channels are present in chemosensing glomus cells of the carotid body and are inhibited by hypoxia. Downstream from this oxygen sensing element is an increase in intracellular calcium in glomus cells followed by neurotransmitter release and a subsequent change in carotid sinus nerve activity. AIM 1 is to develop an in vivo murine model to study CB responses to hypoxia. I will establish in vivo CSN recordings in C57BL/6J mouse strain that is the background strain in many genetically altered mice. In aim 2,1 will explore the role that BK channels play in the overall in vivo carotid body responses to hypoxia. I will use the DBA/2J strain with its higher expression of functional BK channels, the A/J strain with lower expression of BK channels, and BK channel knockout mice (BK-KO) to study the role that BK channels play within the carotid body in response to hypoxia. These two aims will allow us to characterize the role that BK channels play within a functional scope. In order to link this work to chemoreceptor cell function, I will try to link AIM 2's in vivo responses to in vitro measures of glomus cell function. One of the main-stream methods of studying carotid body function in vitro is by measuring changes in glomus cell intracellular calcium. Accordingly, the last aim of my research will be to explore the association between BK channels composition, CSN activity and changes in glomus cell intracellular calcium in the mouse carotid body (AIM 3).

描述（由申请人提供）：颈动脉身体在传感缺氧方面的作用已建立。它也与几种人类健康疾病有关，例如SIDS，睡眠呼吸暂停，先天性中央中央次数不足综合征，慢性心力衰竭和主要高血压。此外，这些疾病与遗传易感性密切相关。为了研究遗传联系的疾病，近交或遗传操纵的小鼠模型是研究的理想工具。响应缺氧，颈动脉体通过增加颈动脉化学感受器传入神经输出来激活呼吸中心。因此，研究总体颈动脉身体功能的最直接方法是测量传入的颈动脉神经活动。这样的研究主要是在大型动物中进行的。尽管几项研究在体外记录了小鼠颈动脉神经活性，但其特征仍未得到很好的描述。不用说，为了将遗传学与颈动脉身体功能改变和人类健康疾病直接联系起来，需要使用近交或遗传操纵小鼠进行体内研究。我的研究的长期目标是研究遗传学在调节颈动脉身体功能和颈动脉身体相关的人类健康疾病中所起的作用。对于此应用，我将在颈动脉体功能和一个分子靶标BK通道的体内评估中桥接。 BK通道存在于颈动脉体的化学效应肾小球细胞中，并被缺氧抑制。该氧气感应元件的下游是肾小球细胞中细胞内钙的增加，然后神经递质释放和随后的颈动脉窦神经活性变化。目的1是开发一个体内鼠模型来研究CB对缺氧的反应。我将在C57BL/6J小鼠菌株中建立体内CSN记录，这是许多遗传改变的小鼠的背景应变。在AIM 2,1中，将探讨BK通道在整个体内颈动脉体内对缺氧的反应中所起的作用。我将使用具有较高表达功能性BK通道表达的DBA/2J菌株，具有BK通道表达较低的A/J菌株以及BK通道基因敲除小鼠（BK-KO）来研究BK通道响应缺氧而在颈动脉体内发挥作用的作用。这两个目标将使我们能够表征BK通道在功能范围内扮演的角色。为了将这项工作与化学感受器细胞功能联系起来，我将尝试将AIM 2的体内响应与肾小球细胞功能的体外测量联系起来。在体外研究颈动脉身体功能的主要方法之一是测量肾小球细胞内钙的变化。因此，我的研究的最后目标是探索BK通道组成，CSN活性和肾小球细胞内钙体内肾小球内钙的变化之间的关联（AIM 3）。