Understanding the molecular mechanisms underlying tympanic membrane homeostasis and repair after injury

了解鼓膜稳态和损伤后修复的分子机制

• 批准号: 10274185
• 负责人: Sonia Scaria
• 金额: $ 3.78万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-04 至 2024-09-03
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10274185
• 关键词: Anatomy; Biology; Cell Fraction; Cell membrane; Cell physiology; Cells; Characteristics; Cholesteatoma; Chronic; Collaborations; Conductive hearing loss; Data Set; Deoxyuridine; Diffuse; Disease; Ear; Environment; Epidermis; Epithelial; External auditory canal; Future; Gene Expression Profile; Genetic Transcription; Hearing; High Prevalence; Histologic; Homeostasis; Hour; Human; Immune; Individual; Inferior; Injury; Intervention; Investigation; Keratosis; Label; Lead; Lifting; Ligands; Location; Maintenance; Malleus; Medical; Membrane Biology; Mentors; Mesenchymal; Mesenchyme; Methods; Molecular; Mucous Membrane; Mus; Operative Surgical Procedures; Otitis Media; Pathogenesis; Pathology; Patients; Pattern; Perforation; Physiological; Platelet-Derived Growth Factor Receptor; Play; Population; Proliferating; Property; Radial; Recurrence; Regulation; Role; Sampling; Signal Transduction; Signaling Protein; Skin; Stratum Basale; Structure; Therapeutic; Tissues; Transcription Alteration; Tympanic Membrane Perforation; Tympanic membrane; Undifferentiated; United States; Work; base; bone morphogenic protein; differential expression; healing; improved; injured; insight; interest; keratinocyte; migration; migratory population; molecular marker; progenitor; receptor; repaired; response; response to injury; single-cell RNA sequencing; small molecule inhibitor; stem cell niche; stem cell population; stem cell proliferation; stem cells; wound; wound healing

PROJECT SUMMARY/ABSTRACT TM perforations are an extremely common pathology of which patients present with conductive hearing loss. Perforations, in general, spontaneously close within 2-3 weeks. Though commonly repaired without intervention, 750,000 surgical procedures are performed each year to close chronic perforations, in which the wound remains open for unknown reasons. Despite this high prevalence, the cause of this condition is unclear. A further investigation into the basic biology of the TM is compulsory to understanding the wound healing of the TM and what is dysregulated in chronic perforations. Wounding in skin, a tissue comparable to the TM, has been heavily studied, but the same sort of in- depth investigation into the biology of TM wounding is required. From recent work of my mentor and colleagues, using 5-ethynyl-2’-deoxyuridine (EdU) labeling, the TM displays a characteristic proliferation pattern, focused predominantly at the handle of the malleus, the first ossicle embedded into the TM, and around the annulus, the outer ring of the TM. From these regions, keratinocytes (KCs) then migrate down and radially outward, but what proliferation looks like in response to injury is unknown. Preliminary single-cell RNA sequencing studies have identified cell populations in the homeostatic TM via transcriptional profiles, revealing populations with characteristics distinct from those seen in other epithelial tissues like skin. This includes a basal KC population with inherent migratory properties. However, how these identified populations of cells coordinate renewal, differentiation, and migration is undefined, but it is critical to understand this to comprehend how the TM maintains homeostasis and repairs itself under the circumstance of injury. Work of the lab has shown that upon wounding, the TM is able to recognize injury and generate a robust proliferative response within 24 hours. Moreover, this proliferative response is not limited to the keratinocyte layer, but also involves the mesenchymal and mucosal layers. Given these Preliminary Studies, my central hypothesis is that healing of the TM involves the coordinated activities of subtypes of cells that are not present under homeostatic conditions. In this proposal, my first Aim is to define the cellular dynamics of healing in the TM following perforation. For my second Aim, I will look to understand the role of Bone Morphogenic Protein (BMP) signaling in maintaining the proliferation of TM keratinocytes under homeostasis and in response to injury. In addition to my mentor’s and co-mentor’s expertise with TM studies, collaborations with Julie Sneddon, Max Krummel, and Sarah Knox support the feasibility of this work. The studies proposed here will aim to define the characteristic cell populations present in the injured TM and define their transcriptional profiles. This will provide crucial insight into how the TM responds to injury and heals. Moreover, potential mechanisms for wound healing will be investigated to inform future therapies for chronic perforation of TMs.

项目摘要/摘要 TM穿孔是一种非常常见的病理，患者表现为传导性听力 损失一般来说，穿孔会在2-3周内自发闭合。虽然通常修复没有 通过干预，每年进行750，000例外科手术以闭合慢性穿孔，其中 伤口还没有愈合原因不明尽管患病率很高，但这种情况的原因尚不清楚。 进一步研究TM的基础生物学对于理解创伤愈合是必要的。 TM和慢性穿孔中的失调。 皮肤中的创伤，一种与TM相当的组织，已经被大量研究，但同样的在- 需要对TM创伤的生物学进行深入调查。从我的导师最近的工作中， 我们的同事，使用5-乙炔基-2 '-脱氧尿苷（EdU）标记，TM显示出特征性的增殖 模式，主要集中在锤骨柄，嵌入TM的第一小骨，以及 在环周围，TM的外环。从这些区域，角质形成细胞（KC）然后向下迁移， 放射状向外扩散，但对损伤的反应是什么样的尚不清楚。初步单细胞 RNA测序研究已经通过转录水平鉴定了稳态TM中的细胞群。 特征，揭示了与其他上皮组织中所见特征不同的人群 比如皮肤。这包括具有固有迁移特性的基础KC群体。然而，这些 确定的细胞群协调更新，分化和迁移是不确定的，但它是至关重要的， 理解这一点，以理解TM如何在这种情况下保持体内平衡和自我修复 伤害。实验室的工作表明，在受伤时，TM能够识别伤害并产生一种 在24小时内出现强烈的增殖反应。此外，这种增殖反应并不限于 除了角质形成细胞层外，还涉及间充质和粘膜层。 鉴于这些初步研究，我的中心假设是，TM的愈合涉及 在稳态条件下不存在的细胞亚型的协调活动。在这项提案中， 我的第一个目标是确定穿孔后TM愈合的细胞动力学。第二个目标，我 将着眼于了解骨形态发生蛋白（BMP）信号在维持增殖中的作用， TM角质形成细胞处于稳态和对损伤的反应。除了我的导师和共同导师 TM研究的专业知识，与朱莉Sneddon，马克斯Krummel和莎拉诺克斯的合作支持 这项工作的可行性。本文提出的研究旨在确定存在的特征性细胞群 并确定它们的转录谱。这将提供关键的洞察力如何TM 对损伤和愈合有反应。此外，还将研究伤口愈合的潜在机制， TM慢性穿孔的未来疗法。