Molecular mechanisms of squamous metaplasia in dry eye

干眼鳞状化生的分子机制

• 批准号: 7642377
• 负责人: Nancy A McNamara
• 金额: $ 33.75万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7642377
• 关键词: Ablation; Age; Antibodies; Area; Autoimmune Process; Binding; Binding Sites; Biological Assay; Biological Markers; C57BL/6 Mouse; Caring; Cells; Clinical; Clinical Markers; Collaborations; Conjunctival Epithelium; Cornea; Cytology; Data; Disease; Distal; Electrophoretic Mobility Shift Assay; Elements; Epithelial Cells; Eye; Eye diseases; Film; Genes; Genetic; Human; Inflammation; Inflammation Mediators; Inflammatory; Interleukin-1; Interleukin-10; International; Knock-out; Knockout Mice; Lead; Link; Liquid substance; Luciferases; MUC5AC gene; Mediating; Modeling; Molecular; Mucins; Mucous Membrane; Mucous body substance; Mus; Ocular cicatricial pemphigoid; Participant; Pathogenesis; Pathology; Patients; Phenotype; Process; Proteins; Provider; Regulator Genes; Reporter; Research Personnel; Response Elements; Role; Sampling; Signal Transduction; Site; Sjogren' s Syndrome; Skin; Squamous Cell; Squamous Metaplasia; Staining method; Stains; Stevens-Johnson Syndrome; Stimulus; Syndrome; Tissues; Topical application; Transcription Factor AP-1; Up-Regulation; Vascularization; Vision; base; clinically relevant; corneal epithelium; cytokine; experience; eye dryness; human subject; impression; improved; in vivo; keratinization; mRNA Expression; mouse model; new therapeutic target; novel; ocular surface; prevent; programs; proline-rich proteins; promoter; response; transcription factor

DESCRIPTION: Squamous metaplasia occurs in severe ocular surfaces diseases (e.g., Stevens-Johnson syndrome (SJS), ocular cicatricial pemphigoid (OCP) and Sjogren's syndrome (SS)) that present some of the most challenging clinical cases facing eye care providers today. By definition, squamous metaplasia is a phenotypic change whereby epithelial cells initiate synthesis of specialized, squamous cell-specific proteins like small proline- rich protein 1B (SPRR1B) to form the cornified envelope (keratinization). While SPRR1B expression is a normal feature of external squamous tissues like the skin, it is a sign of pathology when present in mucosal tissues such as the ocular surface. Very little is known about the molecular mechanisms triggering squamous metaplasia and efforts to inhibit it have so far been unsuccessful. Interestingly, the presence of squamous metaplasia has been extensively correlated with proinflammatory activity of the ocular surface, but the possibility that proinflammatory cytokines released from infiltrating cells actually contribute to squamous metaplasia has never been examined. Based on this, we propose to examine the hypothesis that inflammatory mediators are key regulators of pathological keratinization. Our preliminary data support this possibility and identify IL-1beta as a key participant in this process. In Specific Aim 1, we will validate the use of SPRR1B as a clinical marker for squamous metaplasia in human subjects. SPRR1B expression will be correlated with the levels of inflammatory mediators at the ocular surface using impression cytology and tear samples collected from human patients with SS in collaboration with the Sjogren's International Collaborative Clinical Alliance (SICCA) group at UCSF. In Specific Aim 2, we will examine the role of IL-1beta as a major inducer of squamous metaplasia in a murine model of SS that is lacking the autoimmune regulator (AIRE) gene. Squamous metaplasia in AIRE-deficient mice will be assessed following competitive inhibition and genetic ablation of IL-1 signaling. We will then attempt to reestablish the squamous phenotype through topical application of IL-1beta. In Specific Aim 3, we will use SPRR1B to define gene elements mediating the induction of squamous metaplasia by IL-1beta. This will include traditional luciferase reporter assays and electrophoretic mobility shift assays to identify IL-1beta -response elements on the SPRR1B promoter and bound transcription factors. This combination of translational and molecular approaches will improve our understanding of the pathogenesis of squamous metaplasia and will open the possibility of developing novel treatments to prevent pathological keratinization in human patients.

描述：鳞状化生发生在严重的眼部疾病中（例如，史蒂文斯 - 约翰逊综合征（SJS），眼镜塞卡特型pemphigoid（OCP）和Sjogren综合征（SS）），这些综合征（SS）呈现出今天面临的眼保健提供者面临的最具挑战性的临床病例。根据定义，鳞状化生是一种表型变化，上皮细胞启动特殊的，鳞状细胞特异性蛋白（如小脯氨酸富蛋白1b（SPRR1B））的合成以形成脆性包膜（角质化）。尽管SPRR1b表达是皮肤（如皮肤）的外部鳞状组织的正常特征，但在粘膜组织（例如眼表面）中存在时，它是病理学的标志。关于触发鳞状化生的分子机制以及抑制它的努力，迄今为止未能成功。有趣的是，鳞状化生的存在与眼部表面的促炎活性广泛相关，但是从未研究过从未研究过从未研究过浸润细胞释放的促炎细胞因子实际上会导致鳞状质量的促炎细胞因子。基于此，我们建议探讨炎症介体是病理角化化的关键调节因子的假设。我们的初步数据支持这种可能性，并确定IL-1Beta是此过程的关键参与者。在特定的目标1中，我们将验证使用SPRR1b作为人类受试者中鳞状化生的临床标记。 SPRR1B表达将与印象细胞学和Sjogren的国际协作临床联盟（SICCA）组合作，使用印象细胞学和从SS患者收集的泪液样本与眼表面的炎症介体的水平相关。在特定的目标2中，我们将研究IL-1Beta作为缺乏自身免疫调节剂（AIRE）基因的SS的鼠类模型中的主要诱导剂的主要诱导剂。在竞争性抑制和IL-1信号传导的遗传消融后，将评估AIRE缺陷小鼠中的鳞状化生。然后，我们将尝试通过IL-1Beta的局部应用来重新建立鳞状表型。在特定的目标3中，我们将使用SPRR1b来定义介导IL-1Beta诱导鳞状化生的基因元件。这将包括传统的荧光素酶报告基因测定法和电泳移动性转移测定法，以识别SPRR1B启动子和结合转录因子上的IL -1BETA反应元件。转化方法和分子方法的这种结合将提高我们对鳞状化生的发病机理的理解，并将开辟开发新型治疗方法以防止人类患者的病理角化化的可能性。