Purinergic receptors in inflammation

炎症中的嘌呤能受体

• 批准号: 8081813
• 负责人: WOLFGANG G JUNGER
• 金额: $ 35.09万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-15 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8081813
• 关键词: ATP Receptors; Acute Lung Injury; Address; Adenosine; Adenosine A3 Receptor; Adenosine Triphosphate; Alkaline Phosphatase; Amino Acids; Anions; Area; Back; Cells; Chemical Structure; Chemicals; Chemotactic Factors; Chemotaxis; Complex; Connexins; Disease; Environment; F-Actin; Feedback; Health; Host Defense; Inflammation; Inflammatory; Knowledge; Lead; Mammalian Cell; Mediating; Membrane; Modeling; Multiple Organ Failure; Nucleosides; Nucleotides; Nutritional; Oligonucleotides; Organ; Organ failure; P2Y2 receptor; Patients; Peptides; Play; Process; Property; Purinergic P1 Receptors; Purinoceptor; Recruitment Activity; Rest; Role; Sepsis; Septic Shock; Signal Transduction; Signaling Molecule; Site; Source; Stimulus; System; Testing; Tetrahymena pyriformis; Tissues; Trauma; Work; autocrine; base; cell motility; computerized data processing; design; ecto-nucleotidase; ectoADPase; extracellular; improved; in vivo; migration; mouse model; neutrophil; novel therapeutic intervention; prevent; receptor; research study; response

DESCRIPTION (provided by applicant): Chemotaxis allows polymorphonuclear neutrophils (PMN) to rapidly reach infected and inflamed sites. However excessive influx of PMN damages host tissues. Better knowledge of the mechanisms that control PMN chemotaxis may lead to improved treatments of inflammatory diseases. Based on our recent findings that ATP and adenosine are involved in PMN chemotaxis, we propose to study here how to regulate this purinergic signaling process in order to prevent tissue damage. Purinergic signaling has three essential components: i) sources of the extracellular ATP and adenosine; ii) purinergic receptors that response to ATP and adenosine and, iii) ecto-nucleotidases that modulate cellular responses by hydrolyzing ATP to adenosine. This proposal is based on the following working hypothesis: Chemotactic agents release ATP from PMN. ATP activates nearby P2Y2 receptors, amplifying gradient sensing. A3 adenosine receptors are recruited to the leading edge where adenosine is generated by CD39/E- NTPDase1 and alkaline phosphatase (ALP). Adenosine and positive feedback through A3 receptors drives cell migration, while negative feedback through A2a receptors facilitates membrane retraction at the back of cells. Interfering with these purinergic signaling processes inhibits chemotaxis, which ameliorates PMN-induced tissue damage and organ failure in sepsis and trauma patients. The following specific aims will be addressed: 1. Mechanism of ATP release from PMN: This section will focus on the mechanisms by which PMN release cellular ATP in response to chemotactic stimulation. Specifically, we will focus on the involvement of hTTYH3 tweety maxi-anion channels, connexin hemi-channels, and degranulation. 2. Mechanism of adenosine formation: Experiments are designed to examine the major ecto-nucleotidases that are responsible for the conversion of released ATP to adenosine. Major emphasis will be placed on the contributions of NTPDase1 and ALP. 3. Purinergic signaling complexes: We will explore the co-localization of chemotactic receptors with ATP release sites, purinergic receptors, and ecto-nucleotidases and investigate if purinergic signaling clusters, comprised of these molecules provide "local excitation and global inhibition" as proposed in theoretical chemotaxis models. 4. Role of purinergic signaling in vivo: We will study the roles of P2Y2, A3, A2a, and NTPDase1 and ALP in mouse models and test the feasibility of targeting these molecules to prevent host tissue damage. The proposed studies are expected to improve our understanding of the mechanisms that control chemotaxis. This could lead to novel therapeutic approaches to ameliorate host tissue damage caused by excessive influx of activated PMN, for example, in trauma and septic shock patients. PUBLIC HEALTH RELEVANCE: Chemotaxis, a key functional response of neutrophils in health and disease is still poorly understood. In this project we propose to determine how release of cellular ATP and purinergic receptors control chemotaxis and whether this control mechanism can be pharmacologically targeted to prevent inflammation and host tissue damage in trauma patients.

描述(申请人提供)：趋化作用使中性粒细胞(PMN)迅速到达感染和炎症部位。然而，PMN的过度内流会损害宿主组织。更好地了解控制PMN趋化的机制可能会改善炎症性疾病的治疗。根据我们最近的发现，ATP和腺苷参与了PMN的趋化作用，我们建议在这里研究如何调节这个嘌呤能信号过程，以防止组织损伤。嘌呤能信号有三个基本组成部分：i)细胞外ATP和腺苷的来源；ii)对ATP和腺苷作出反应的嘌呤能受体；iii)通过将ATP水解为腺苷来调节细胞反应的胞外核苷酸酶。这一建议基于以下工作假设：趋化剂从中性粒细胞释放ATP。三磷酸腺苷激活附近的P2Y2受体，放大梯度感应。A3腺苷受体被招募到由CD39/E-NTPDase1和碱性磷酸酶(ALP)产生腺苷的前沿。腺苷和通过A3受体的正反馈驱动细胞迁移，而通过A2a受体的负反馈促进细胞背面的膜回缩。干扰这些嘌呤能信号传递过程会抑制趋化作用，从而改善败血症和创伤患者中性粒细胞引起的组织损伤和器官衰竭。具体目标如下：1.中性粒细胞释放三磷酸腺苷的机制：本节将重点介绍中性粒细胞在趋化刺激下释放细胞三磷酸腺苷的机制。具体地说，我们将重点讨论hTTYH3微调最大阴离子通道、连接蛋白半通道和脱颗粒。2.腺苷形成机制：实验旨在研究负责将释放的ATP转化为腺苷的主要胞外核苷酸酶。主要重点将放在NTPDase1和ALP的贡献上。3.嘌呤能信号复合体：我们将探索趋化受体与ATP释放位点、嘌呤能受体和胞外核苷酸酶的共存，并研究由这些分子组成的嘌呤能信号簇是否如理论趋化模型所提出的那样提供“局部兴奋和全局抑制”。4.嘌呤能信号在体内的作用：我们将在小鼠模型中研究P2Y2、A3、A2a、NTPDase1和ALP的作用，并测试这些分子靶向预防宿主组织损伤的可行性。这些拟议的研究有望提高我们对控制趋化性的机制的理解。这可能导致新的治疗方法，以改善由过量的活化PMN流入引起的宿主组织损伤，例如，在创伤和感染性休克患者中。公共卫生相关性：趋化性是中性粒细胞在健康和疾病中的关键功能反应，目前仍知之甚少。在这个项目中，我们建议确定细胞内ATP和嘌呤能受体的释放如何控制趋化作用，以及这种控制机制是否可以作为药物靶向来预防创伤患者的炎症和宿主组织损伤。