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.

项目总结/摘要 表皮形成多层上皮，作为身体的保护屏障，防止 脱水和病原体入侵。它的主要细胞成分，角质形成细胞，不断再生， 当它们在组织中向外移动时，通过专门的分化形式来破坏皮肤屏障。结束时 角质形成细胞生活在皮肤的最外层，它们启动一个称为角质化的细胞重塑程序， 在这个过程中，它们消除细胞器，形成扁平的角化细胞。这个过程的重要性在于 强调了许多与缺陷性角质形成细胞成熟相关的角质形成障碍。尽管出现了 炎症性皮肤病的生物治疗，表皮的类似靶向治疗的发展， 由于对角质形成细胞的驱动途径的不完全理解， 分化拟议的目标通过应用先进的显微镜、基因 编辑和光遗传学来定义介导人表皮细胞器降解的机制。 这项建议建立在PI的K 08项目的基础上，该项目发现角质形成细胞诱导自噬， 溶酶体降解途径，分解细胞器。K 08资助的工作表明， 角质形成细胞上调自噬受体NIX，NIX标记了角质形成细胞中的线粒体和指示细胞。 上组织层分解这些细胞器，这是表皮成熟必不可少的一步。我们 计划中的实验将扩大K 08项目的范围，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的分解（称为 网状吞噬）。目的1将确定网状细胞吞噬如何驱动角化过程中的程序化ER降解 目标2将评估网状细胞吞噬是否减轻角质形成细胞中ER应激的损伤。初步研究 鉴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， 内质网应激导致的细胞器损伤我们将在器官型皮肤中使用获得和丧失功能的方法， 以确定这些受体在指导表皮形态发生和减轻ER应激中的作用。作为 我们将利用活体生物传感器成像和光遗传学工具来确定网状吞噬是如何改变信号传导的， 控制角质形成细胞分化的介质，包括钙和活性氧。结果 计划中的工作有望确定使表皮分化正常化的新策略， 角化，而且还用于修复常见疾病如特应性皮炎和银屑病中的屏障功能障碍。 增加华盛顿大学的投资，以确保他作为一个物理学家和科学家的成功， R 03资金将促进PI的职业发展，并使他能够在竞争R 01级别资金时， 转变为独立调查员。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，建立一个创新的研究计划，补充他的临床 专业，并为未来的翻译工作提供了平台，以寻找皮肤屏障疾病的新疗法。