Novel Roles of GRK2 and beta-arrestin2 on mast cell-mediated allergy and Inflammation

GRK2 和 β-arrestin2 对肥大细胞介导的过敏和炎症的新作用

• 批准号: 10611941
• 负责人: Hydar Ali
• 金额: $ 48.51万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-14 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10611941
• 关键词: ADRBK1 gene; Actins; Adaptor Signaling Protein; Allergic Contact Dermatitis; Allergic Disease; Anaphylaxis; Antigens; Arr2; Asthma; Atopic Dermatitis; Attenuated; B-Cell Lymphomas; CRISPR/Cas technology; Cell Aggregation; Cell Degranulation; Cell surface; Cells; Cellular biology; Chemotaxis; Connective Tissue; Cutaneous; Development; Disease; Environment; G protein coupled receptor kinase; G-Protein-Coupled Receptors; Generations; Hematopoietic; Histamine; Homeostasis; Host Defense; Hypersensitivity; IgE; IgE Receptors; Immune; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Life; Mediating; Membrane Proteins; Modeling; Molecular; Mucosa- associated lymphoid tissue lymphoma translocation protein-1; Mucous Membrane; Mus; Neurogenic Inflammation; PRKCA gene; Pain; Passive Cutaneous Anaphylaxis; Pathway interactions; Peritoneal; Phosphorylation; Play; Polymers; Production; Protein Dephosphorylation; Proto-Oncogene Proteins c-akt; Pruritus; Pulmonary Inflammation; Regulation; Resistance; Role; Scaffolding Protein; Signal Pathway; Signal Transduction; Skin Tissue; Testing; Tissues; Tryptase; airway hyperresponsiveness; allergic response; beta-arrestin; chemokine; chronic inflammatory disease; cofilin; cytokine; depolymerization; desensitization; in vivo; mast cell; mutant; novel; novel strategies; novel therapeutics; polymerization; protein activation; protein kinase C beta; receptor; recruit; response

Summary: Mast cell (MC) activation through the aggregation of cell surface IgE receptors (FcεRI) leads to life- threatening conditions such as anaphylaxis and asthma. Recent exciting development in MC biology has been the discovery that they express a novel G protein coupled receptor (GPCR) known as MRGPRX2 (mouse counterpart MrgprB2), which contributes to a growing list of conditions such as pseudoallergy, neurogenic inflammation, non-histaminergic itch, allergic contact dermatitis and atopic dermatitis. The main objective of this proposal is to modulate FcεRI and MrgprB2-mediated responses by targeting novel signaling pathways in MCs. Following their activation, most GPCRs undergo desensitization via their phosphorylation by GPCR kinases (GRKs) and the recruitment of the adapter proteins, β-arrestins (β-arrs). We made four novel observations, which provide the basis of this proposal. First, we found that unlike most GPCRs, MRGPRX2 is resistant to GRK2-mediated desensitization but it contributes to IgE-mediated MC degranulation and cytokine production. Second, β-arr2 inhibits both IgE and MrgprB2-mediated MC degranulation by modifying unknown components downstream of Ca2+ mobilization. Third, β-arr2 contributes to MC chemotaxis in vitro and allergic contact dermatitis in vivo. Fourth, the effect of β-arr2 on MC chemotaxis is associated with Ser3 dephosphorylation of the actin depolymerization factor cofilin. While activation of protein kinase Cβ (PKCβ) promotes MC degranulation, PKCα phosphorylates cofilin at Ser23 and Ser24 to increase actin polymerization, resulting in cessation of degranulation. Based on these findings, we hypothesize that GRK2 promotes IgE- mediated responses in MCs via the regulation of Syk/Akt/NF-κB signaling but β-arr2 modulates both FcεRI and MrgprB2 responses by functioning as a scaffolding protein for phosphorylation and dephosphorylation of cofilin. In aim 1, we will determine the role of GRK2 on FcεRI-mediated MC degranulation and cytokine generation in vitro and allergic response in vivo. In aim 2, we will determine the role of β-arr2 on FcεRI and MrgprB2- resposnes in vitro and inflammatory responses in vivo. Completion of this study may provide better rationale for the development of novel therapeutics for the MC-mediated disorders.

概括： 肥大细胞（MC）通过细胞表面IgE受体（FCεRI）的聚集而激活，导致生命 威胁性条件，例如过敏和哮喘。 MC生物学的最新发展是 他们表达了一种新型G蛋白偶联受体（GPCR）的发现称为MRGPRX2（小鼠 同行MRGPRB2），这有助于越来越多的疾病列表，例如伪ALLERGY，神经源 炎症，非希斯明能瘙痒，过敏性接触性皮炎和特应性皮炎。主要目标 该建议是通过针对新的信号通路来调节FCεRI和MRGPRB2介导的响应 MCS。 激活后，大多数GPCR通过GPCR磷酸化进行脱敏 激酶（GRK）和衔接蛋白的募集β-arrestin（β-arrs）。我们做了四本小说 观察结果，这提供了本提案的基础。首先，我们发现与大多数GPCR不同，MRGPRX2是 对GRK2介导的脱敏的抗性，但有助于IgE介导的MC脱粒和细胞因子 生产。其次，β-arr2通过修改未知 Ca2+动员下游的组件。第三，β-arr2在体外和过敏性中有助于MC趋化性 在体内接触皮炎。第四，β-arr2对MC趋化性的影响与Ser3有关 肌动蛋白解聚因子cofilin的去磷酸化。而蛋白激酶Cβ（PKCβ）的激活 促进MC脱粒化，PKCα磷酸化Cofilin在Ser23和Ser24上增加肌动蛋白聚合，以增加肌动蛋白聚合， 导致停止脱粒。根据这些发现，我们假设GRK2促进了IgE- 通过调节SYK/AKT/NF-κB信号传导，MC中介导的响应，但β-arr2调节FcεRI和 MRGPRB2反应通过作为脚手架蛋白的磷酸化和磷酸化蛋白质的作用。 在AIM 1中，我们将确定GRK2对FcεRI介导的MC脱粒和细胞因子产生的作用 体内体外和过敏反应。在AIM 2中，我们将确定β-arr2对FcεRI和MRGPRB2-的作用 体内的体外和炎症反应。这项研究的完成可能会提供更好的理由 为了开发用于MC介导的疾病的新疗法。