Neutrophil chemotaxis in autoinflammation

描述(申请人提供)：中性粒细胞介导的炎症有助于许多疾病的发病，包括自体炎症综合征、心脏病、哮喘、风湿病和炎症性肠病。炎症反应的一个关键早期步骤是中性粒细胞定向迁移到炎症部位。这项建议的总体目标是了解体内调节中性粒细胞趋化的基本分子机制，并以斑马鱼为模型系统了解这些机制如何促进慢性炎症的发展。这一建议的优势在于使用了我们开发的新型转基因斑马鱼品系来研究体内中性粒细胞的趋化和炎症。利用这些工具，我们观察到斑马鱼中性粒细胞在组织和血管系统之间表现出双向迁移，而中性粒细胞的反向迁移有助于炎症反应的缓解。指导这项研究的假设是，G蛋白偶联受体(GPCR)、肌醇磷脂信号和适配蛋白PSTPIP1介导的中性粒细胞趋化作用调节中性粒细胞在组织和血管系统之间的双向转移和体内炎症的发展。我们现在独一无二地利用改进的方法在斑马鱼中性粒细胞中高效瞬时表达转基因或生物传感器探针，以剖析体内调节中性粒细胞趋化和双向迁移的分子机制。因此，我们提出了以下具体目标：1.阐明肌醇磷脂信号如何调控斑马鱼中性粒细胞双向转运和炎症。2.阐明CXCR4介导的GPCR信号通路如何调控斑马鱼中性粒细胞的双向转运和炎症反应；3.以斑马鱼为模型系统，在体内检测自身炎症性疾病中性粒细胞的趋化作用。这项研究不仅将阐明调节中性粒细胞趋化的分子机制，还可能为慢性炎症的发病机制提供洞察力，并为控制炎症是发病机制的核心的疾病状态的开发提供新的治疗方法。公共卫生相关性：这项拟议的研究以斑马鱼为模型系统，通过增加我们对调节白细胞运动、伤口愈合和炎症的分子机制的理解，为人类健康做出贡献。了解体内调节中性粒细胞趋化的基本机制应该有助于确定自体炎症综合征和其他疾病状态的治疗靶点，在这些疾病中，炎症是发病机制的核心，包括心脏病、哮喘、关节炎和炎症性肠病。

DESCRIPTION (provided by applicant): Neutrophil-mediated inflammation contributes to the pathogenesis of many diseases including autoinflammatory syndromes, heart disease, asthma, rheumatic disease and inflammatory bowel disease. A key early step in the inflammatory response is the directional migration of neutrophils to sites of inflammation. The overall goal of this proposal is to understand the basic molecular mechanisms that regulate neutrophil chemotaxis in vivo, and to understand how these mechanisms contribute to the development of chronic inflammation using zebrafish as a model system. The strength of this proposal lies in the use of novel transgenic zebrafish lines that we have developed to study neutrophil chemotaxis and inflammation in vivo. Using these tools we have made the observation that zebrafish neutrophils exhibit bidirectional migration between tissues and the vasculature, and reverse neutrophil migration contributes to resolution of the inflammatory response. The hypothesis that guides this research is that neutrophil chemotaxis mediated by G-protein coupled receptors (GPCR), phosphoinositide signaling and the adaptor protein PSTPIP1 modulate bidirectional neutrophil trafficking between tissues and the vasculature and the development of inflammation in vivo. We are now uniquely positioned with improved methods for high efficiency transient expression of transgenes or biosensor probes in zebrafish neutrophils to dissect the molecular mechanisms that regulate neutrophil chemotaxis and bidirectional migration in vivo. Accordingly, we propose the following specific aims: 1. Elucidate how phosphoinositide signaling regulates bidirectional neutrophil trafficking and inflammation in zebrafish. 2. Elucidate how GPCR signaling through CXCR4 regulates bidirectional neutrophil trafficking and inflammation in zebrafish, and 3. Use zebrafish as a model system to examine neutrophil chemotaxis in autoinflammatory disease in vivo. The research proposed in this grant will not only elucidate the molecular mechanisms that regulate neutrophil chemotaxis, but will also likely provide insight into the pathogenesis of chronic inflammation and the development of new therapeutic for control of disease states in which inflammation is central to pathogenesis. PUBLIC HEALTH RELEVANCE: The proposed research contributes to human health by increasing our understanding of the molecular mechanisms that regulate leukocyte motility, wound healing and inflammation using zebrafish as a model system. Knowledge of the basic mechanisms that regulate neutrophil chemotaxis in vivo should aid in the identification of therapeutic targets for autoinflammatory syndromes and other disease states in which inflammation is central to pathogenesis, including heart disease, asthma, arthritis and inflammatory bowel disease.