Purinergic receptors in inflammation

炎症中的嘌呤能受体

基本信息

批准号：
8287705
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
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-06-15 至 2014-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8287705
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

项目摘要

PURINERGIC RECEPTORS IN INFLAMMATION - 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. Narrative 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.

炎症中的嘌呤能受体 - 趋化性允许多形核中性粒细胞 (PMN) 快速到达感染和发炎部位。然而，PMN 的过度流入会损害宿主组织。更好的了解控制 PMN 趋化性的机制可能会改善炎症治疗疾病。根据我们最近发现 ATP 和腺苷参与 PMN 趋化性，我们提出在这里研究如何调节这种嘌呤能信号传导过程以防止组织损伤。嘌呤能信号传导具有三个重要组成部分：i) 细胞外 ATP 和腺苷的来源； ii) 嘌呤能响应 ATP 和腺苷的受体，以及，iii) 通过调节细胞反应的核酸外切酶 ATP 水解为腺苷。该提案基于以下工作假设：趋化剂从 PMN 中释放 ATP。 ATP 激活附近的 P2Y2 受体，放大梯度传感。 A3 腺苷受体被募集到 CD39/E- 产生腺苷的前缘 NTPDase1 和碱性磷酸酶 (ALP)。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后部的膜收缩。干扰这些嘌呤能信号传导过程会抑制趋化性，从而改善 PMN 诱导的趋化性脓毒症和创伤患者的组织损伤和器官衰竭。将实现以下具体目标： 1. PMN释放ATP的机制：本节将重点介绍PMN释放ATP的机制细胞 ATP 对趋化刺激作出反应。具体来说，我们将重点关注 hTTYH3 tweety 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：设计实验来检查主要的核酸外切酶负责将释放的 ATP 转化为腺苷。主要重点将放在 NTPDase1 和 ALP 的贡献。 3. 嘌呤能信号复合物：我们将探索趋化受体与 ATP 的共定位释放位点、嘌呤能受体和核酸外切酶，并研究嘌呤能信号簇是否由这些分子组成提供了理论中提出的“局部激发和全局抑制” 趋化性模型。 4.体内嘌呤信号的作用：我们将研究P2Y2、A3、A2a、NTPDase1和ALP的作用在小鼠模型中并测试靶向这些分子以防止宿主组织损伤的可行性。拟议的研究预计将提高我们对控制趋化性机制的理解。这可能会带来新的治疗方法来改善因过度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，激活的 PMN 的存在。叙述趋化性是中性粒细胞在健康和疾病中的一种关键功能反应，但人们对趋化性的了解仍知之甚少。在这个我们建议确定细胞 ATP 和嘌呤能受体的释放如何控制趋化性和这种控制机制是否可以通过药理学靶向来预防炎症和宿主组织创伤患者的损伤。