Regulation of Paracellular Permeability by IFNgamma and TNFa

IFNγ 和 TNFa 对细胞旁通透性的调节

• 批准号: 7252409
• 负责人: JERROLD R. TURNER
• 金额: $ 33.98万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7252409
• 关键词: Actomyosin; Biochemical; Cells; Characteristics; Clinical; Crohn' s disease; Cytoskeletal Modeling; Data; Development; Disease; Disruption; Enteral; Epithelial; Event; Figs - dietary; Foundations; Functional disorder; Future; Goals; Health; Human; Image; Immune; In Situ; In Vitro; Infection; Inflammatory; Interferon Type II; Interferons; Intestinal Diseases; Intestines; Knockout Mice; Lamina Propria; Lead; Light; MYLK gene; Mediating; Medical; Modality; Molecular; Mus; Myosin Light Chain Kinase; Myosin Light Chains; Myosin Type II; Oligopeptides; Pathogenesis; Permeability; Phosphorylation; Process; Protein Dynamics; Proteins; Regulation; Relative (related person); Reperfusion Injury; Research; Research Personnel; Resistance; Role; Signal Transduction; Structure; T-Cell Activation; TNFRSF1A gene; TNFRSF1B gene; Testing; Therapeutic; Therapeutic Effect; Tight Junctions; Time; Transcriptional Regulation; Tumor Necrosis Factor Receptor; Tumor Necrosis Factor-alpha; Tumor Necrosis Factors; Up-Regulation; Wild Type Mouse; absorption; base; cytokine; experience; graft vs host disease; human TNF protein; human disease; in vivo; inhibitor/antagonist; innovation; intestinal epithelium; kinase inhibitor; loss of function; novel; prevent; programs; protein distribution; receptor expression; restoration; success

DESCRIPTION (provided by applicant): Loss of epithelial barrier function is characteristic of inflammatory, infectious, ischemic, and immune mediated intestinal diseases. Synergistic signaling between the TH1 cytokines interferon-gamma (IFNgamma) and tumor necrosis factor-alpha (TNFalpha), which are frequently elevated in these diseases, has been implicated in this barrier dysfunction. In turn, compromised barrier function can allow noxious nominal material to access the lamina propria, stimulate immune cells, and augment IFNgamma and TNFalpha release, culminating in a self-amplifying cycle of epithelial dysfunction. In vivo data show that barrier dysfunction can be reversed by anti-TNF a therapies. We have recently shown that IFN gamma / TNFalpha -induced loss of barrier function is related to increased myosin light chain (MLC) phosphorylation and that both loss of barrier function and increased MLC phosphorylation can be reversed by a novel oligopeptide MLC kinase inhibitor. Despite this, the mechanisms by which IFNgamma / TNFalpha increase MLC phosphorylation and decrease barrier function are not well understood. Characterization of these regulatory mechanisms is important to understanding the pathogenesis of diverse intestinal diseases and may also identify novel targets for therapy of IFNgamma / TNFalpha -driven intestinal disease. This may lead to the development of effective non-immunosuppresive therapies for diseases such as Crohn's disease, enteric infection, ischemia-reperfusion injury, and graft versus host disease. The central hypothesis of this proposal is that IFNgamma and TNFalpha synergize to activate a signaling cascade that results in increased TNF receptor expression, increased MLC kinase expression, increased MLC phosphorylation, tight junction reorganization, and epithelial barrier dysfunction. The aims of this application are to test this hypothesis by i) determining the role of IFNgamma in enhancing epithelial responsiveness to TNFalpha and the mechanisms by which IFNgamma and TNalpha synergize to increase MLC phosphorylation, ii) defining the effects of IFNgamma and TNFalpha on tight junction protein dynamics using integrated functional, biochemical, and real time imaging approaches, and iii) exploring the effects of IFNgamma and TNFalpha on the regulation of MLC phosphorylation in vivo using knockout mice and pharmacologic agents that prevent IFNgamma / TNFalpha -induced barrier dysfunction in vitro. We expect that these studies will have significant positive effects on human health because they will lead to the development of new understanding of the mechanisms by which barrier function is compromised in disease and will provide the foundation necessary for the development of strategies for enhancement of barrier function as a therapeutic modality.

描述（由申请人提供）：上皮屏障功能丧失是炎症、感染、缺血和免疫介导的肠道疾病的特征。 TH1 细胞因子干扰素γ (IFNγ) 和肿瘤坏死因子-α (TNFα) 之间的协同信号传导在这些疾病中经常升高，与这种屏障功能障碍有关。反过来，屏障功能受损会使有害的名义物质进入固有层，刺激免疫细胞，并增加 IFNγ 和 TNFα 的释放，最终导致上皮功能障碍的自我放大循环。体内数据表明，抗TNFα疗法可以逆转屏障功能障碍。我们最近表明，IFN γ / TNF α 诱导的屏障功能丧失与肌球蛋白轻链 (MLC) 磷酸化增加有关，并且屏障功能丧失和 MLC 磷酸化增加都可以通过新型寡肽 MLC 激酶抑制剂逆转。尽管如此，IFNγ/TNFα 增加 MLC 磷酸化和降低屏障功能的机制尚不清楚。这些调节机制的表征对于理解不同肠道疾病的发病机制非常重要，并且还可以确定治疗 IFNgamma / TNFalpha 驱动的肠道疾病的新靶点。这可能会导致开发出针对克罗恩病、肠道感染、缺血再灌注损伤和移植物抗宿主病等疾病的有效非免疫抑制疗法。该提议的中心假设是 IFNγ 和 TNFα 协同激活信号级联，导致 TNF 受体表达增加、MLC 激酶表达增加、MLC 磷酸化增加、紧密连接重组和上皮屏障功能障碍。本申请的目的是通过 i) 确定 IFNgamma 在增强上皮细胞对 TNFα 反应性中的作用以及 IFNgamma 和 TNalpha 协同增加 MLC 磷酸化的机制，ii) 确定 IFNgamma 和 TNFalpha 对紧密连接的影响来检验这一假设。使用集成功能、生化和实时成像方法研究蛋白质动力学，以及 iii) 使用以下方法探索 IFNgamma 和 TNFalpha 对体内 MLC 磷酸化调节的影响敲除小鼠和预防 IFNgamma / TNFalpha 体外诱导的屏障功能障碍的药物。我们期望这些研究将对人类健康产生显着的积极影响，因为它们将导致对疾病中屏障功能受损的机制产生新的认识，并将为制定增强屏障功能的策略提供必要的基础作为一种治疗方式。