Contribution of Macropinocytosis in fibroblast activation and systemic sclerosis

巨胞饮作用在成纤维细胞活化和系统性硬化症中的作用

• 批准号: 10551908
• 负责人: Konstantin Tsoyi
• 金额: $ 17.6万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10551908
• 关键词: Acceleration; Actins; Address; Amiloride; Amino Acids; Animal Model; Apoptosis; Attenuated; Autoimmune Diseases; Automobile Driving; Cause of Death; Cell Aging; Cell Survival; Cells; Cessation of life; Clathrin; Complex; Complication; Data; Dedications; Dermal; Development; Disease; Effector Cell; Endocytosis; Environment; Extracellular Fluid; Extracellular Matrix; Fatty Acids; Fibroblasts; Fibrosis; Gene Expression; Genetic Transcription; Goals; High Prevalence; Imipramine; In Vitro; Interstitial Lung Diseases; Invaded; Laboratories; Lung; Lung fibrogenesis; Mediating; Molecular; Morbidity - disease rate; Mus; Myofibroblast; Nutrient; Organ; Organelles; Pathogenesis; Pathogenicity; Patients; Pharmaceutical Preparations; Phenotype; Phosphatidylinositols; Phosphotransferases; Pinocytosis; Play; Prevalence; Process; Production; Profibrotic signal; Proteins; Publishing; Pulmonary Fibrosis; Research; Resistance; Respiratory Failure; Rheumatism; Role; Scleroderma; Signal Pathway; Skin; Smooth Muscle; Systemic Scleroderma; TGFB1 gene; Techniques; Testing; Therapeutic; Therapeutic Intervention; Tuberous Sclerosis; United States; United States Food and Drug Administration; Vacuolar Protein Sorting; Vascular Diseases; Virus; cancer cell; cell motility; clinical heterogeneity; effective therapy; extracellular; feasibility testing; fibrogenesis; in vivo; indium-bleomycin; inhibitor; loss of function; member; migration; mortality; pharmacologic; polypeptide; programs; response; skin fibrosis; therapeutic target; transcriptome sequencing; uptake

PROJECT SUMMARY/ABSTRACT This R21 proposal describes a two-year research plan that will facilitate research program dedicated to determining the role of macropinocytosis in systemic sclerosis (SSc, scleroderma) and SSc-associated interstitial lung disease (ILD). SSc is an autoimmune disorder, which is manifested by skin fibrosis, vasculopathy and the fibrosis of internal organs. The prevalence of SSc is estimated to range from 50 to 300 per million across the world, with one of the highest prevalence rates observed in the United States at 240 per million. Because of its clinical heterogeneity, SSc is a challenging disease to manage which results in the highest disease mortality among the rheumatologic diseases. ILD is the most common lung complication of SSc and is associated with increased mortality. ILD occurs in up to 80% of patients with SSc, with 25–30% developing a severe progressive form of SSc-ILD leading to eventual respiratory failure and death. Little is known about the molecular mechanisms involved in the pathogenesis of SSc and SSc-ILD. This project will focus on elucidating the key roles of macropinocytosis in skin and lung fibrogenesis, as well as its therapeutic targeting. Macropinocytosis is an actin-dependent but clathrin-independent endocytic process that mediates the nonselective internalization of extracellular contents, such as proteins, cell debris, or viruses. Macropinocytosis has been shown to be involved in cell survival, migration and invasion by providing nutrients (e.g., free amino acids and polypeptides) from extracellular environment. However, its role in scleroderma and organ fibrogenesis is unknown. Our preliminary findings suggest that inhibition of macropinocytosis attenuates dermal myofibroblast differentiation and pulmonary fibrosis in mice. Furthermore, we found that vacuolar protein sorting 34 (Vps34), a sole member of class III phosphoinositide-3-kinase (PI3K), is involved in macropinocytosis and fibroblast activation. Based on published and our preliminary findings, we hypothesize that increased macropinocytosis promotes the development of dermal and lung fibrosis in SSc. Thus, its inhibition exerts anti-fibrotic effects in the animal model of skin fibrosis by reducing profibrotic responses in activated fibroblasts. We also hypothesize that Vps34 is essential for macropinocytosis, which in turn confers to fibroblast activation. We will test our hypotheses by addressing the following Specific Aims: Specific Aim #1: To demonstrate that macropinocytosis inhibition attenuates dermal and lung fibrosis in mice by inhibiting fibroblast to myofibroblast differentiation, ECM production, and migration. Specific Aim #2: To demonstrate that Vps34 is a key protein in macropinosome formation and contributes to profibrotic responses of dermal and lung fibroblasts.

项目概要/摘要 该 R21 提案描述了一项为期两年的研究计划，该计划将促进致力于以下方面的研究计划： 确定巨胞饮作用在系统性硬化症（SSc、硬皮病）和 SSc 相关间质中的作用 肺部疾病（ILD）。 SSc 是一种自身免疫性疾病，表现为皮肤纤维化、血管病变和 内脏器官纤维化。据估计，SSc 的患病率在每百万人中 50 至 300 人之间。 美国是世界上患病率最高的国家之一，为每百万人 240 人。由于其 临床异质性，SSc 是一种具有挑战性的疾病，导致最高的疾病死亡率 风湿病之中。 ILD 是 SSc 最常见的肺部并发症，与 死亡率增加。高达 80% 的 SSc 患者会出现 ILD，其中 25-30% 会发展为严重进行性进展 SSc-ILD 形式导致最终呼吸衰竭和死亡。人们对分子知之甚少 SSc 和 SSc-ILD 的发病机制。该项目将重点阐明关键 巨胞饮作用在皮肤和肺纤维发生中的作用及其治疗靶向。巨胞饮作用是 肌动蛋白依赖但不依赖网格蛋白的内吞过程，介导非选择性内化 细胞外内容物，例如蛋白质、细胞碎片或病毒。巨胞饮作用已被证明参与其中 通过提供营养物质（例如游离氨基酸和多肽）来促进细胞存活、迁移和侵袭 细胞外环境。然而，其在硬皮病和器官纤维形成中的作用尚不清楚。我们的初步 研究结果表明，抑制巨胞饮作用会减弱真皮肌成纤维细胞的分化， 小鼠肺纤维化。此外，我们发现液泡蛋白分选 34 (Vps34) 是 III 类磷酸肌醇 3 激酶 (PI3K) 参与巨胞饮作用和成纤维细胞活化。基于 发表和我们的初步研究结果，我们假设巨胞饮作用的增加会促进 SSc 中皮肤和肺纤维化的发展。因此，它的抑制在细胞中发挥抗纤维化作用 通过减少活化成纤维细胞的促纤维化反应来建立皮肤纤维化动物模型。我们也 假设 Vps34 对于巨胞饮作用至关重要，而巨胞饮作用又会导致成纤维细胞活化。 我们将通过解决以下具体目标来检验我们的假设： 具体目标#1：证明 巨胞饮抑制作用通过抑制成纤维细胞转变为肌成纤维细胞来减轻小鼠的真皮和肺纤维化 分化、ECM 生产和迁移。具体目标#2：证明 Vps34 是 巨胞质体的形成并有助于真皮和肺成纤维细胞的促纤维化反应。