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： 通过细胞表面 IgE 受体 (FcεRI) 的聚集激活肥大细胞 (MC)，从而导致生命- 过敏反应和哮喘等威胁性疾病。 MC 生物学最近令人兴奋的发展是 发现它们表达一种新型 G 蛋白偶联受体 (GPCR)，称为 MRGPRX2（小鼠 对应的 MrgprB2），它会导致越来越多的病症，例如假性过敏、神经源性过敏 炎症、非组胺性瘙痒、过敏性接触性皮炎和特应性皮炎。主要目标 该提案旨在通过靶向新的信号通路来调节 FcεRI 和 MrgprB2 介导的反应 MC。 激活后，大多数 GPCR 通过 GPCR 磷酸化而经历脱敏 激酶 (GRK) 和接头蛋白 β-抑制蛋白 (β-arrs) 的募集。我们做了四本小说 意见，这些意见为本提案提供了基础。首先，我们发现与大多数 GPCR 不同，MRGPRX2 抵抗 GRK2 介导的脱敏，但有助于 IgE 介导的 MC 脱颗粒和细胞因子 生产。其次，β-arr2 通过修饰未知蛋白来抑制 IgE 和 MrgprB2 介导的 MC 脱颗粒。 Ca2+ 动员的下游成分。第三，β-arr2有助于体外MC趋化性和过敏性 体内接触性皮炎。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。同时激活蛋白激酶 Cβ (PKCβ) 促进 MC 脱粒，PKCα 在 Ser23 和 Ser24 处磷酸化丝切蛋白以增加肌动蛋白聚合， 导致脱粒停止。基于这些发现，我们假设 GRK2 促进 IgE- 通过调节 Syk/Akt/NF-κB 信号传导介导 MC 反应，但 β-arr2 调节 FcεRI 和 MrgprB2 通过充当 cofilin 磷酸化和去磷酸化的支架蛋白来做出反应。 在目标 1 中，我们将确定 GRK2 在 FcεRI 介导的 MC 脱颗粒和细胞因子生成中的作用 体外和体内过敏反应。在目标 2 中，我们将确定 β-arr2 对 FcεRI 和 MrgprB2- 的作用 体外反应和体内炎症反应。完成这项研究可能会提供更好的理由 为 MC 介导的疾病开发新疗法。