Neurotrophins in the Lung

肺中的神经营养素

• 批准号: 7792333
• 负责人: Y. S. Prakash
• 金额: $ 37.78万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7792333
• 关键词: Address; Affinity; Agonist; Area; Asthma; Biochemistry; Brain-Derived Neurotrophic Factor; Bronchoconstrictor Agents; Cells; Chronic Bronchitis; Cyclic ADP-Ribose; Data; Designer Drugs; Development; Disease; Family; Fluorescence; Foundations; Functional disorder; Generations; Goals; Growth Factor; Human; Hypersensitivity; Image; Immune; In Vitro; Inflammation; Inflammation Mediators; Inflammatory; Interleukins; Knock-in Mouse; Knowledge; Literature; Lung; Malignant Neoplasms; Malignant neoplasm of lung; Measurement; Mechanics; Mediating; Molecular Biology; Morphology; Mus; Muscle Contraction; Myosin Light Chains; Myosin Regulatory Light Chains; NGFR Protein; Nerve; Nerve Growth Factor Receptors; Nerve Growth Factors; Nervous system structure; Neurons; Neurotrophic Tyrosine Kinase Receptor Type 2; Neurotrophin 3; Ovalbumin; Pathway interactions; Pharmacology; Phospholipase C; Physiology; Publishing; Pulmonary Emphysema; Receptor Activation; Regulation; Relative (related person); Research; Resistance; Rho-associated kinase; Role; Ryanodine Receptor Calcium Release Channel; Ryanodine Receptors; Sarcoplasmic Reticulum; Second Messenger Systems; Shortness of Breath; Signal Transduction; Smooth Muscle; Smooth Muscle Myocytes; Source; Techniques; Tissues; Transgenic Mice; Tumor Necrosis Factor-alpha; Tumor Necrosis Factors; Up-Regulation; Work; airway hyperresponsiveness; airway inflammation; base; cytokine; immunocytochemistry; mouse model; neurotrophic factor; new therapeutic target; novel; public health relevance; receptor; receptor expression; respiratory smooth muscle; response; second messenger

DESCRIPTION (provided by applicant): An exciting, new investigative theme in airway physiology and pathophysiology is neurotrophins (NTs): growth factors including brain-derived neurotrophic factor (BDNF) known for their diverse roles in the nervous system. NTs and their receptors have now been found in different lung components including airway smooth muscle (ASM), with altered expression observed in asthma, allergy, and even lung cancer. While NTs may be derived from several sources, our published and preliminary data suggest that ASM is a target of NTs, and that NTs contribute not only to ASM contractility under normal circumstances, but also to increased contractility with airway inflammation (such as that induced by TNFa). The long term goal of the proposed studies is to understand the role of NTs in ASM physiology and pathophysiology. The overall hypothesis is that NTs enhance a) sarcoplasmic reticulum (SR) Ca2+ release and Ca2+ influx; and b) Ca2+ sensitivity for force generation in ASM. We propose that BDNF is a key NT influencing ASM contractility. Finally, airway inflammation enhances BDNF signaling, leading to an overall enhancement of [Ca2+]i and force. In this proposal, we will use human ASM and the ovalbumin (OVA) mouse model to examine the relative role of the BDNF receptors (high affinity TrkB vs. low affinity p75NTR) vis-¿vis ASM contractility. We hypothesize that TrkB is more important for [Ca2+]i regulation, while p75NTR regulates force. Using biochemistry, pharmacology, molecular biology, immunocytochemistry, fluorescence Ca2+ imaging, force measurement techniques, and lung mechanics, we will focus on specific mechanisms that may be regulated by BDNF: the second messengers IP3 (via phospholipase C PLC) and cyclic ADP ribose (via CD38) (Aim 1); SR Ca2+ release (IP3 receptor vs. ryanodine receptor (RyR) channels) (Aim 2); Ca2+ influx via store-operated Ca2+ entry (SOCE) (Aim 3) and the force regulatory mechanisms myosin light chain (MLC20) and rhoA/rho-kinase (Aim 4). These in vitro studies in human ASM will be integrated into the OVA mouse model applied in focus studies to the TrkB knockin mouse (where TrkB functionality is reversibly inhibited). We will explore the idea that inflammation induced by TNFa increases constitutive BDNF receptor expression, and alters specific [Ca2+]i and force regulatory mechanisms, thus priming ASM for enhanced response to both BDNF and bronchoconstrictor. The Specific Aims are: Aim 1: To determine mechanisms by which BDNF modulates second messenger signaling in human ASM; Aim 2: To determine mechanisms by which BDNF modulates SR Ca2+ regulation in human ASM; Aim 3: To determine mechanisms by which BDNF modulates SOCE in human ASM; Aim 4: To determine mechanisms by which BDNF modulates force regulation in human ASM; Aim 5: To determine the role of BDNF in ASM contractility in a mouse model of airway inflammation and hyperresponsiveness. PUBLIC HEALTH RELEVANCE. There is increasing recognition that abnormalities in airway smooth muscle contractility (exacerbated by inflammation) contribute to exaggerated airway narrowing and accompanying shortness of breath in clinically important diseases such as asthma and chronic bronchitis. In this regard, the potential role of growth factors called neurotrophins in regulation of airway contractility is an exciting and emerging area of research. By establishing the role of neurotrophins in airway narrowing with or without inflammation, the proposed studies will the foundation for better understanding of airway diseases, and potential development of new therapeutic targets.

描述（由申请人提供）：气道生理学和病理生理学中一个令人兴奋的新研究主题是神经营养因子（NT）：包括脑源性神经营养因子（BDNF）在内的生长因子以其在神经系统中的多种作用而闻名。现在，在包括气道平滑肌 (ASM) 在内的不同肺部成分中发现了 NT 的表达，在哮喘、过敏甚至肺癌中观察到 NT 的表达发生了改变。初步数据表明，ASM 是 NT 的靶标，NT 不仅有助于正常情况下的 ASM 收缩性，而且还有助于增加气道炎症（例如 TNFa 诱导的炎症）的收缩性。目的是了解 NT 在 ASM 生理学和病理生理学中的作用 总体假设是 NT 增强 a) 肌浆网 (SR) Ca2+ 释放和 Ca2+ 流入； b) ASM 中的 Ca2+ 对力产生的敏感性。最后，气道炎症增强 BDNF 信号传导，导致 [Ca2+]i 和力的整体增强。人类 ASM 和卵清蛋白 (OVA) 小鼠模型，用于检查 BDNF 受体（高亲和力 TrkB 与低亲和力 p75NTR）的相对作用相对于 ASM 收缩性，我们认为 TrkB 对于 [Ca2+]i 调节更重要，而 p75NTR 调节力，我们将利用生物化学、药理学、分子生物学、免疫细胞化学、荧光 Ca2+ 成像、力测量技术和肺力学来重点研究。 BDNF 可能调节的机制：第二信使 IP3（通过磷脂酶 C PLC）和环 ADP 核糖（通过 CD38）（目的1); SR Ca2+ 释放（IP3 受体与兰尼碱受体 (RyR) 通道）（目标 2）；通过钙池操纵的 Ca2+ 进入 (SOCE) 流入 Ca2+（目标 3）和肌球蛋白轻链 (MLC20) 的力调节机制rhoA/rho-激酶（目标 4）。这些针对人类 ASM 的体外研究将被整合到应用于重点研究的 OVA 小鼠模型中。 TrkB 敲入小鼠（其中 TrkB 功能被可逆性抑制）我们将探讨 TNFa 诱导的炎症增加组成型 BDNF 受体表达，并改变特定的 [Ca2+]i 和力调节机制，从而启动 ASM 增强对 BDNF 和 BDNF 的反应。具体目标是： 目标 1：确定 BDNF 调节人类 ASM 中第二信使信号传导的机制； BDNF 在人类 ASM 中调节 SR Ca2+ 调节的机制；目标 3：确定 BDNF 在人类 ASM 中调节 SOCE 的机制；目标 4：确定 BDNF 在人类 ASM 中调节力调节的机制；目标 5：确定其作用； BDNF 在气道炎症和高反应性小鼠模型中的收缩力的影响 人们越来越认识到这一点。气道平滑肌收缩力异常（因炎症而加剧）会导致哮喘和慢性支气管炎等临床重要疾病中气道过度狭窄并伴有呼吸短促。在这方面，称为神经营养因子的生长因子在调节气道收缩力方面的潜在作用是。通过确定神经营养素在有或没有炎症的气道狭窄中的作用，拟议的研究将为更好地了解气道疾病和新治疗靶点的潜在开发奠定基础。