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: 10471885
• 负责人: Sonia Scaria
• 金额: $ 5.18万
• 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/10471885
• 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穿孔是一种极为常见的病理学，患者出现导电性听力 损失。一般而言，穿孔在2-3周内在赞助下关闭。虽然通常没有修理 干预措施，每年进行75万手术程序，以关闭慢性穿孔，其中 由于未知原因，伤口仍然开放。尽管患病率很高，但这种情况的原因尚不清楚。 对TM的基本生物学的进一步研究是强制性的，以了解伤口的愈合 TM以及慢性穿孔中的失调。 与TM相当的组织中的皮肤受伤已经大量研究了，但是相同的In- 需要对TM图的生物学进行深度研究。从我的导师和 同事，使用5-乙基-2'-脱氧尿苷（EDU）标签，TM显示出特征性的增殖 模式，主要聚焦于麦龙的手柄上，第一个嵌入到TM中的Ossicle，并且 周围是TM的外环。从这些地区，角质形成细胞（KC）然后迁移，然后 放射线向外，但是响应伤害的增殖是未知的。初步单细胞 RNA测序研究通过转录鉴定了稳态TM中的细胞群体 剖面，揭示了与其他上皮组织中看到的特征不同的种群 喜欢皮肤。这包括具有继承迁移特性的基本KC人群。但是，这些是如何的 鉴定的细胞种群协调更新，分化和迁移是不确定的，但至关重要 理解这一点以理解TM如何保持体内稳态并在这种情况下进行修复 受伤。实验室的工作表明，获胜后，TM能够识别伤害并产生 在24小时内稳健增殖的反应。而且，这种增殖的反应不仅限于 角质形成层，但也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的治愈涉及 在稳态条件下不存在的细胞亚型的协调活性。在此提案中， 我的第一个目的是定义穿孔后TM中愈合的细胞动力学。为了我的第二个目标 将要了解骨形态发生蛋白（BMP）信号在维持的增殖中的作用 稳态下的TM角质形成细胞并应对损伤。除了我的心理和联合主管 TM研究的专业知识，与Julie Sneddon，Max Krummel和Sarah Knox的合作支持 这项工作的可行性。这里提出的研究将旨在定义存在的特征细胞种群 在受伤的TM中并定义其转录曲线。这将提供有关TM的关键见解 对伤害和康复的反应。此外，将研究伤口愈合的潜在机制以告知 TMS长期穿孔的未来疗法。