The Central Role of IL-33 in Immune-Mediated Scarring

IL-33 在免疫介导的疤痕形成中的核心作用

• 批准号: 9001805
• 负责人: Sergei P. Atamas
• 金额: --
• 依托单位: BALTIMORE VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9001805
• 关键词: Address; Affect; Animal Model; Anti-Inflammatory Agents; Anti-inflammatory; Asthma; Attenuated; Binding; Bleomycin; Breathing; CCL2 gene; COL1A1 gene; COL1A2 gene; Cell Culture Techniques; Cell Nucleus; Cell Surface Receptors; Cells; Chromatin; Cicatrix; Collagen; Collagen Gene; Connective Tissue; Cytokine Signaling; Data; Deposition; Development; Disease; Disease Pathway; Dust; Endothelial Cells; Epithelial; Extracellular Matrix; Fibroblasts; Fibrosis; Future; Gene Activation; Gene Delivery; Gene Expression; Genes; Genetic Transcription; Goals; Health; Healthcare; Heart; Human; Hypersensitivity; Immune; Immune response; Immunosuppressive Agents; Inflammation; Inflammatory; Injury; Interleukin-1; Interleukin-13; Interleukin-4; Interleukin-6; Interleukins; Investigation; Kidney; Lead; Left; Life; Ligands; Literature; Liver; Lung; Lymphocyte; MMP3 gene; Macrophage Inflammatory Protein-1; Maps; Matrix Metalloproteinases; Mediating; Military Personnel; Modeling; Mus; Necrosis; Nuclear; Organ; Parasites; Pathogenesis; Pathway interactions; Patients; Personal Satisfaction; Play; Poison; Poly I-C; Production; Proteins; Publishing; Radiation; Regulation; Research; Role; Sentinel; Smooth Muscle; Source; TLR3 gene; TLR4 gene; TNF gene; Therapeutic immunosuppression; Tissue Therapy; Tissues; Transcriptional Regulation; Veterans; adaptive immunity; base; cell type; cytokine; experience; extracellular; functional disability; immune activation; improved; in vivo; indium-bleomycin; innovation; macrophage; mouse model; new therapeutic target; older patient; particle; promoter; public health relevance; response

DESCRIPTION (provided by applicant): Exaggerated scarring, or fibrosis, complicates a spectrum of diseases, occurs in all organs, and can be relentless, debilitating, and deadly. It is particularly prevalent in older patients and thoe who have experienced military exposures, posing a serious problem for veterans. Exaggerated innate and adaptive immune responses drive fibrosis, yet the exact mechanisms remain incompletely understood. Recent findings suggest a role for interleukin (IL)-33 in the pathogenesis of fibrosis. IL-33 exists in two forms and has a dual activity. Intranuclear IL-33 (INIL33) is bound to chromatin and appears to regulate gene expression. By contrast, extracellular IL-33 (EXIL33) acts by binding to the cell-surface receptor T1/ST2 and facilitating Th2 responses. The activities of EXIL33 are under active investigation, whereas the activities of INIL33 have been underappreciated and not studied in detail or in association with disease. Our data suggest that fibrosis is driven primarily (yet not exclusively) by INIL33. The levels of INIL3 are elevated in tissues of patients with fibrosis as well as in the mouse model of bleomycin injury, in which the INIL33 form predominates over EXIL. Gene delivery of INIL33 in cell culture and in the animal model leads to collagen accumulation, increased production of profibrotic cytokines and matrix metalloproteinases, as well as Smad3 activation, all of which are known to contribute to fibrosis. When combined with bleomycin injury, INIL33 potentiates collagen accumulation and the expression of profibrotic cytokines. There is minimal, if any, conversion of INIL33 to EXIL33, no signs of Th2 activation, and gene deficiency of T1/ST2 has minimal, if any, attenuating effect on INIL33-driven fibrosis. We hypothesize that INIL33 is a T1/ST2-independent, Th2-independent, upstream activator of multiple profibrotic mechanisms and that elevated expression of INIL33 in fibroblasts contributes to collagen deposition by these cells through direct and indirect mechanisms. The following Specific Aims will be addressed: 1. Functionally map the IL-33 molecule to identify regions in this protein that confer nuclear localization, chromatin binding, and transcriptional regulation in cultured primary human fibroblasts and in mice in vivo. 2. Define the relative roles of direct mechanisms (binding to the collagen promoter and upregulating collagen gene transcription) and indirect mechanisms (both T1/ST2-dependent and -independent regulation of profibrotic cytokines and matrix metalloproteinases) of profibrotic regulation of fibroblasts by IL-33 in cell culture. 3. Delineate the pathophysiological roles of fibroblast-specific expression of IL-33 and of the T1/ST2 cell-surface receptor in vivo by determining the effects of fibroblast-specific IL-33 deficiency, ubiquitous IL-33 deficiency, and ubiquitous T1/ST2 deficiency on inflammation and fibrosis in the bleomycin injury model. Successful completion of these studies will clarify the role and mechanisms of fibroblast activation by INIL-33, laying the groundwork for future development of rational IL-33-targeting antifibrotic strategies.

描述（由申请人提供）： 过度的疤痕或纤维化会使一系列疾病复杂化，发生在所有器官中，并且可能是无情的、令人衰弱的和致命的。它在老年患者和经历过军事暴露的人中尤其普遍，给退伍军人带来了严重的问题。过度的先天性和适应性免疫反应会导致纤维化，但确切的机制仍不完全清楚。最近的研究结果表明白细胞介素 (IL)-33 在纤维化发病机制中发挥作用。 IL-33以两种形式存在并具有双重活性。核内 IL-33 (INIL33) 与染色质结合，似乎可以调节基因表达。相比之下，细胞外 IL-33 (EXIL33) 通过与细胞表面受体 T1/ST2 结合并促进 Th2 反应发挥作用。 EXIL33 的活性正在积极研究中，而 INIL33 的活性尚未得到充分重视，并且没有进行详细研究或与疾病的关联。我们的数据表明纤维化主要（但不完全）由 INIL33 驱动。在纤维化患者的组织以及博来霉素损伤的小鼠模型中，INIL3 的水平升高，其中 INIL33 形式比 EXIL 形式占主导地位。 INIL33 在细胞培养物和动物模型中的基因传递会导致胶原蛋白积累、促纤维化细胞因子和基质金属蛋白酶的产生增加以及 Smad3 激活，所有这些都已知会导致纤维化。当与博莱霉素损伤相结合时，INIL33 会增强胶原蛋白的积累和促纤维化细胞因子的表达。 INIL33 向 EXIL33 的转化（如果有的话）也很小，没有 Th2 激活的迹象，并且 T1/ST2 基因缺陷对 INIL33 驱动的纤维化的减弱作用（如果有的话）也很小。我们假设 INIL33 是一种不依赖于 T1/ST2、不依赖于 Th2 的多种促纤维化机制的上游激活剂，并且成纤维细胞中 INIL33 表达的升高通过直接和间接机制促进这些细胞的胶原沉积。将解决以下具体目标： 1. 对 IL-33 分子进行功能图谱，以识别该蛋白质中在培养的原代人成纤维细胞和小鼠体内赋予核定位、染色质结合和转录调节的区域。 2. 定义细胞培养中 IL-33 对成纤维细胞的促纤维化调节的直接机制（与胶原启动子结合并上调胶原基因转录）和间接机制（促纤维化细胞因子和基质金属蛋白酶的 T1/ST2 依赖性和独立调节）的相对作用。 3. 描绘 通过确定成纤维细胞特异性 IL-33 缺乏、普遍存在的 IL-33 缺乏和普遍存在的 T1/ST2 缺乏对博莱霉素损伤模型中炎症和纤维化的影响，研究体内成纤维细胞特异性表达 IL-33 和 T1/ST2 细胞表面受体的病理生理学作用。这些研究的成功完成将阐明INIL-33激活成纤维细胞的作用和机制，为未来开发合理的IL-33靶向抗纤维化策略奠定基础。