Mechanisms of reticulophagy and ER stress mitigation in epidermis

表皮网状吞噬和内质网应激缓解机制

• 批准号: 10726427
• 负责人: Cory L Simpson
• 金额: $ 8.83万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10726427
• 关键词: Acceleration; Address; Atopic Dermatitis; Automobile Driving; Autophagocytosis; Autophagosome; Award; BCL2/Adenovirus E1B 19kd Interacting Protein 3-Like; Binding; Biological Process; Biological Response Modifier Therapy; Biosensor; Body Surface; Buffers; Calcium; Cell Differentiation process; Cell Nucleus; Cells; Cellular biology; Clinical; Compensation; Complement; Confocal Microscopy; Data; Degradation Pathway; Dehydration; Dermatologic; Dermatology; Development; Disease; Electrons; Endoplasmic Reticulum; Ensure; Epidermis; Epithelium; Functional disorder; Funding; Future; Genes; Goals; Histologic; Homeostasis; Human; Ichthyoses; Image; Infection; Inflammatory; Inherited; Injury; Invaded; Investments; Keratosis Follicularis; Knock-out; Knowledge; Lasers; Life; Link; Lysosomes; Mediating; Mediator; Membrane; Methods; Microscopic; Microscopy; Mitochondria; Modeling; Morphogenesis; Natural regeneration; Organelles; Pathology; Pathway interactions; Patients; Physicians; Positioning Attribute; Process; Psoriasis; Reactive Oxygen Species; Reporting; Research; Research Personnel; Role; Route; Scientist; Signal Transduction; Skin; Testing; Tissue Model; Tissues; Toxic effect; Tubular formation; Universities; Up-Regulation; Washington; Work; candidate identification; career development; cell injury; endoplasmic reticulum stress; experimental study; gain of function; human tissue; improved; in vivo; innovation; keratinization; keratinocyte; keratinocyte differentiation; loss of function; medical specialties; microscopic imaging; novel; novel strategies; optogenetics; pathogen; premature; prevent; programs; protein expression; rational design; receptor; repaired; resilience; sensor; skin barrier; skin disorder; skin regeneration; stressor; success; targeted treatment; tool; transcriptome sequencing

Project Summary/Abstract The epidermis forms a multi-layered epithelium that serves as a protective shield for the body, preventing dehydration and pathogen invasion. Its principal cellular constituents, keratinocytes, continually regenerate the cutaneous barrier via a specialized form of differentiation as they move outward in the tissue. At the end of their life in the skin’s outermost layers, keratinocytes initiate a cellular remodeling program called cornification in which they eliminate their organelles to form flattened, keratinized cells. The importance of this process is underscored by many disorders of cornification linked to defective keratinocyte maturation. Despite the advent of biologic treatments for inflammatory skin diseases, development of similar targeted therapies for epidermal barrier dysfunction has been limited by an incomplete understanding of the pathways driving keratinocyte differentiation. The proposed aims address this knowledge gap by applying advanced microscopy, gene editing, and optogenetics to define the mechanisms mediating organelle degradation in human epidermis. This proposal builds on the PI’s K08 project, which found that cornifying keratinocytes induce autophagy, a lysosomal degradation pathway, to break down organelles. The K08-funded work showed that differentiating keratinocytes upregulate an autophagy receptor, NIX, which marked mitochondria and instructed cells in the upper tissue layers to break down these organelles, a step that was essential for epidermal maturation. Our planned experiments will expand the K08 project scope to include the endoplasmic reticulum (ER), testing the hypothesis that keratinocytes utilize distinct autophagy receptors to orchestrate breakdown of the ER (called reticulophagy). Aim 1 will determine how reticulophagy drives programmed ER degradation during cornification and Aim 2 will assess if reticulophagy mitigates damage from ER stress in keratinocytes. Preliminary studies identified candidate receptors that initiate reticulophagy in either a constitutive manner during cornification or upon organelle injury due to ER stress. We will use gain- and loss-of-function approaches in organotypic skin to determine the role of these receptors in directing epidermal morphogenesis and mitigating ER stress. As well, we will leverage live biosensor imaging and optogenetic tools to define how reticulophagy alters signaling mediators that control keratinocyte differentiation, including calcium and reactive oxygen species. Results from the planned work promise to identify novel strategies for normalizing epidermal differentiation in disorders of cornification but also for repairing barrier dysfunction in common diseases like atopic dermatitis and psoriasis. Augmenting the investment by the University of Washington to ensure his success as a physician-scientist, R03 funding will advance the PI’s career development and position him to compete for R01-level funding as he transitions to an independent investigator. The proposed project enhances the PI’s expertise at the intersection of cell biology and dermatology, building an innovative research program that complements his clinical specialty and provides a platform for future translational work to find novel treatments for skin barrier disorders.

项目概要/摘要 表皮形成多层上皮，作为身体的保护罩，防止 脱水和病原体入侵，其主要细胞成分角质形成细胞不断再生。 当它们在组织中向外移动时，通过特殊形式的分化形成皮肤屏障。 角质形成细胞生活在皮肤的最外层，启动称为角质化的细胞重塑程序 他们消除细胞器以形成扁平的角化细胞，这一过程的重要性在于。 尽管出现了许多与角质形成细胞成熟缺陷有关的角质化疾病，但仍强调了这一点。 炎症性皮肤病的生物治疗，开发类似的表皮靶向治疗 由于对角质形成细胞驱动途径的不完全了解，屏障功能障碍受到限制 拟议的目标是通过应用先进的显微镜、基因来解决这一知识差距。 编辑和光遗传学来定义介导人类表皮细胞器降解的机制。 该提案建立在 PI 的 K08 项目的基础上，该项目发现角化角质形成细胞诱导自噬，这是一种 K08 资助的工作表明，可以通过溶酶体降解途径来分解细胞器。 角质形成细胞上调自噬受体 NIX，该受体标记线粒体并指示细胞 上层组织分解这些细胞器，这是表皮成熟所必需的步骤。 计划中的实验将扩大K08项目范围以包括内质网（ER），测试 假设角质形成细胞利用不同的自噬受体来协调 ER（称为 目标 1 将确定网状噬菌体如何在角质化过程中驱动内质网降解。 目标 2 将评估网状噬菌体是否可以减轻角质形成细胞内质网应激造成的损伤。 确定了在角化过程中以组成型方式启动网状吞噬的候选受体 由于 ER 应激导致细胞器损伤，我们将在器官型皮肤中使用功能获得和丧失的方法。 确定这些受体在指导表皮形态发生和减轻内质网应激中的作用。 好吧，我们将利用活体生物传感器成像和光遗传学工具来定义网状噬菌体如何改变信号传导 控制角质细胞分化的介质，包括钙和活性氧。 计划的工作有望确定使表皮分化正常化的新策略 角质化，还可以修复特应性皮炎和牛皮癣等常见疾病的屏障功能障碍。 增加华盛顿大学的投资，以确保他作为一名医生科学家的成功， R03 资金将促进 PI 的职业发展，并使他能够竞争 R01 级别的资金，因为他 拟议的项目增强了 PI 在交叉点的专业知识。 细胞生物学和皮肤病学的研究人员，建立了一个创新的研究项目来补充他的临床 专业并为未来的转化工作提供一个平台，以寻找皮肤屏障疾病的新疗法。