AGE-RELATED OLFACTORY LOSS: MECHANISMS AND TREATMENT OPTIONS

与年龄相关的嗅觉丧失：机制和治疗方案

• 批准号: 9103698
• 负责人: JAMES E. SCHWOB
• 金额: $ 5.72万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9103698
• 关键词: A Mouse; Abbreviations; Ablation; Address; Age; Aging; Antibodies; Apical; Area; Basal Cell; Biological Assay; Birth; Brain; Breeding; Cell Aging; Cell Line; Cell physiology; Cells; Cessation of life; Chronic; Colony-Forming Units Assay; Diphtheria Toxin; Disease; Doxycycline; Environment; Epithelial; Epithelium; Experimental Models; Failure; Functional disorder; Genetic; Genetic Models; Genetic Recombination; Genetic Transcription; Genotype; Grant; Health; Human; In Vitro; Injury; Interneurons; Investigation; Knock-out; Lead; Lesion; Longevity; Maps; Measures; Metaplasia; Mitotic Activity; Modeling; Multipotent Stem Cells; Mus; Natural regeneration; Neurons; Nutritional status; Odorant Receptors; Olfactory Epithelium; Olfactory Pathways; Operative Surgical Procedures; Pathology; Patients; Population; Production; Quality of life; Recovery; Rejuvenation; Research; Reserve Stem Cell; Response Elements; Risk; Sensory; Staining method; Stains; Stem cells; Stress; Structure; Structure of respiratory epithelium; Synapses; Tamoxifen; Testing; Tetanus Helper Peptide; Tetracyclines; Therapeutic; Thymidine; Tissues; Toxin; Trans-Activators; Transgenic Mice; Transplantation; Tyrosine 3-Monooxygenase; Work; age related; aged; analog; base; cell age; density; design; exhaust; exhaustion; falls; functional status; in vivo; injured; methyl bromide; mouse model; nerve supply; neurogenesis; olfactory bulb; olfactory sensory neurons; premature; progenitor; reconstitution; reinnervation; repaired; research study; restoration; stem; stem cell population; sustentacular cell; transcription factor

DESCRIPTION (provided by applicant): Abnormalities of stem cell function and/or the destruction of stem cells lead to an olfactory epithelium (OE) that remains olfactory (including a full apical lining composed of sustentacular cells), but one that has no neurons (OSNs), no globose basal cells (GBCs), and no ongoing neurogenesis - a condition that we term neurogenic exhaustion. We have developed a mouse model based on the expression of Diptheria toxin subunit A (DTA) in OMP-expressing mature OSNs that causes a tetracycline-reversible abbreviation of normal neuronal life-span and causes proliferation to accelerate at first, but then eventually dissipate. Aim 1 proposes experiments to understand when and how GBC stem cell failure develops by analyzing the GBC population as a function of age, as well as its capacity to generate olfactospheres in culture and engraft after transplantation - both of the latter phenomena assay the functional status of the progenitor population. Aim 2 shifts its focus to a second type of olfactory stem cell called horizontal basal cells (HBCs). Unlike GBCs, the HBCs persist in aneuronal OE, but are not functioning as multipotent progenitors/stem cells as they can do when the epithelium is directly injured and more than just neurons are dying. The HBCs will be activated out of their dormancy by a conditional knock-out strategy aimed at the transcription factor p63. We will test whether the GBCs that originate from the HBCs will persist and repopulate the epithelium. Aim 3 will assay whether restoration of the neuronal population, in this case by taking advantage of the reversibility of our DTA-driven experimental model and stopping the premature death of the neurons, results in correct reinnervation of the olfactory bulb. The experiments in Aim 3 will establish whether it is realistic to expect that the rejuvenation of the stem and progenitor populations and the reestablishment of neuronal input to the CNS can restore appropriate function. Currently, the complete lack of therapeutic options for patients with olfactory disease provides a strong justification for pursuing this research.

描述（由申请人提供）：干细胞功能的缺失和/或干细胞的破坏导致嗅觉上皮（OE）保持嗅觉（包括由支持细胞组成的完整顶端衬里），但没有神经元（OSN），没有球状基底细胞（GBC），也没有持续的神经发生-我们称之为神经源性衰竭的状况。我们已经开发了一种小鼠模型，该模型基于白喉毒素亚单位A（DTA）在表达OMP的成熟OSN中的表达，该成熟OSN导致正常神经元寿命的四环素可逆缩短，并导致增殖开始加速，但随后 最终消散。目的1提出了实验，以了解何时以及如何GBC干细胞失败的发展，通过分析GBC人口作为年龄的函数，以及它的能力，以产生嗅球的培养和移植后的移植-后两种现象检测祖细胞群体的功能状态。Aim 2将焦点转移到第二种称为水平基底细胞（HBC）的嗅觉干细胞。与GBC不同，HBC在神经元OE中持续存在，但不像上皮直接损伤时那样作为多能祖细胞/干细胞发挥作用，而不仅仅是神经元死亡。HBCs将通过针对转录因子p63的条件性敲除策略被激活而脱离其休眠。我们将测试源自HBCs的GBC是否会持续存在并重新填充上皮。目的3将分析神经元群体的恢复是否会导致嗅球的正确神经再支配，在这种情况下，通过利用我们的DTA驱动的实验模型的可逆性并阻止神经元的过早死亡。目标3中的实验将确定预期干细胞和祖细胞群的再生以及CNS神经元输入的重建可以恢复适当功能是否现实。目前，嗅觉疾病患者完全缺乏治疗选择，这为开展这项研究提供了强有力的理由。