Molecular Regulation of Neutrophil Transcellular Migration'

中性粒细胞跨细胞迁移的分子调控

• 批准号: 8961440
• 负责人: Marie-Dominique Filippi
• 金额: $ 30.81万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8961440
• 关键词: Accounting; Adaptor Signaling Protein; Adhesives; Affect; Biology; Blood; Blood - brain barrier anatomy; Blood Vessels; Cadherins; Cell Communication; Cell physiology; Cells; Clinical; Complex; Data; Disease; Disseminated Malignant Neoplasm; Encephalitis; Endothelial Cells; Endothelium; Enzymes; Exhibits; Extravasation; Failure; Future; Genetic; Goals; Host Defense Mechanism; ITGAM gene; Immune System Diseases; Immunofluorescence Immunologic; Infection; Infection Control; Infiltration; Inflammation; Inflammation Process; Inflammatory; Injury; Integrins; Leukocytes; Malignant Neoplasms; Matrix Metalloproteinases; Mediating; Membrane; Metastatic to; Molecular; Mus; Neutrophil Activation; Outcome; Output; PTEN gene; Peptide Hydrolases; Phenotype; Phosphoric Monoester Hydrolases; Phosphotransferases; Physiological; Process; Protein Isoforms; Proteins; Proteomics; Proto-Oncogene Proteins c-akt; Reaction; Regulation; Research; Role; Route; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Specific qualifier value; Stream; Testing; Tissues; base; cancer cell; design; in vivo; insight; intravital imaging; intravital microscopy; microorganism; migration; mouse model; neutrophil; novel; novel therapeutics; prevent; public health relevance; spatiotemporal

 DESCRIPTION (provided by applicant): Neutrophils are the first line of cellular defense by moving rapidly to sites of infection in tissue. This migration is tightly regulated; indeed, aberrat accumulation of neutrophils causes tissue injury. Despite the clinical importance, the mechanisms of neutrophil migration into tissues remain poorly understood. Our long-term goal is to identify the signaling pathways that limit neutrophil tissue infiltration and inflammation. A critical step in that process is neutrophil migration across the endothelium, known as "diapedesis." Diapedesis is not solely a migration step. It is also important for neutrophil activation and subsequent functions via neutrophil-endothelial cell interactions, and for endothelial barrier integrity. Hence, it directly participates in inflammation. Interestingly, unequivocal evidence indicates that diapedesis can occur between or through endothelial cells (paracellular or transcellular, respectively). But, the mechanisms that separately control these two modes of migration are poorly understood. How distinct migration paths impact outcome of inflammation is not known. Understanding these mechanisms is important for our understanding of neutrophil biology and inflammation. More broadly, it will reveal principle that may apply to other cells, including cancer cells. It is fundamental clinically because targeting only one mode of migration could offer new ways to dampen hyperinflammation while preserving some host defense mechanism. We found that Ras proximity 1 (Rap1) isoform Rap1b limits neutrophil diapedesis and inflammation. Rap1b-/- neutrophils exhibit increased diapedesis, due to a selective increase in transcellular migration. This is caused by enhanced PIP3-Akt activity-mediated invasive protrusions. Rap1b loss enhanced inflammation, which is prevented by Akt inhibition in vivo. Hence, neutrophil activation via signaling outputs control diapedesis route and inflammation outcome. We hypothesize that the spatiotemporal organization of signaling, regulated by Rap1b, phosphatase, PIP3 and metallo-proteinases (MMPs), specifies diapedesis route via protrusions-mediated neutrophil-endothelial cell interactions - and, as a result modulates inflammatory reactions. We will pursue the following aims. Aim1 will study the role of Rap1b, phosphatases and PIP3 in diapedesis. Aim 2 will test the hypothesis that specific neutrophil invadopodia components, including substrates of PIP3, proteases and MMP, control neutrophil/endothelial cell interactions for transcellular migration. Aim 3 will use intravital imaging to investigate mechanism of neutrophil diapedesis in vivo. It will examine the relationship between route choice and inflammation in vivo. The clinical impact should be significant, since the proposed aims focus on molecules (ie, AKT, CD11b, phosphatase [SHP-1, PTEN, SHIP-1/2]) that are associated with inflammatory, immune disorders, and cancer. We anticipate the study will uncover completely novel mechanisms of neutrophil diapedesis. It will pave the way to designing novel therapeutic opportunities to inflammation, and more broadly to metastatic cell extravasation into tissues, as Rap1b inactivation and subsequent targets are associated with some metastatic cancers.

 描述（由申请人提供）：中性粒细胞是细胞防御的第一道防线，其快速移动到组织中的感染部位；事实上，中性粒细胞的异常积累会导致组织损伤，尽管中性粒细胞的机制具有临床重要性。我们对向组织的迁移仍知之甚少，我们的长期目标是确定限制中性粒细胞组织浸润和炎症的信号通路。 该过程中的关键步骤是中性粒细胞穿过内皮细胞的迁移，称为“血细胞渗出”。血细胞渗出不仅仅是一个迁移步骤，它对于中性粒细胞通过中性粒细胞与内皮细胞相互作用的激活和后续功能以及内皮屏障的完整性也很重要。 ，它直接参与炎症，明确的证据表明血细胞渗出可以发生在内皮细胞之间或通过内皮细胞（分别是细胞旁或跨细胞）。分别控制这两种迁移模式的机制尚不清楚。了解这些机制对于我们了解中性粒细胞生物学和炎症很重要，更广泛地说，它将揭示可能适用于其他疾病的原理。这在临床上很重要，因为仅针对一种迁移模式可以提供抑制过度炎症的新方法，同时保留一些宿主防御机制。 Rap1b-/- 中性粒细胞表现出血细胞渗出增加，这是由 PIP3-Akt 活性介导的侵袭性突起增强引起的，而这种情况可通过体内 Akt 抑制来预防。通过信号输出激活中性粒细胞控制血球传播途径 我们研究了由 Rap1b、磷酸酶、PIP3 和金属蛋白酶 (MMP) 调节的信号传导的时空组织，通过突起介导的中性粒细胞-内皮细胞相互作用指定血细胞渗出途径，从而调节炎症反应。将追求以下目标：Aim1 将研究 Rap1b、磷酸酶和 PIP3 在中的作用。目标 2 将检验特定中性粒细胞侵入伪足成分（包括 PIP3、蛋白酶和 MMP 的底物）控制中性粒细胞/内皮细胞跨细胞迁移的相互作用的假设。目标 3 将使用活体成像来研究中性粒细胞渗出的体内机制。检查途径选择与体内炎症之间的关系，临床影响应该是显着的，因为拟议的目标集中在分子（即 AKT、 CD11b、磷酸酶 [SHP-1、PTEN、SHIP-1/2]）与炎症、免疫疾病和癌症相关，我们预计这项研究将揭示中性粒细胞血渗的全新机制，这将为设计新的机制铺平道路。炎症的治疗机会，更广泛的是转移细胞外渗到组织中的机会，因为 Rap1b 失活和随后的靶标与一些转移性癌症相关。