Table_1_Age-Related Differences in Structure and Function of Nasal Epithelial Cultures From Healthy Children and Elderly People.xlsx

The nasal epithelium represents the first line of defense against inhaled pathogens, allergens, and irritants and plays a key role in the pathogenesis of a spectrum of acute and chronic airways diseases. Despite age-dependent clinical phenotypes triggered by these noxious stimuli, little is known about how aging affects the structure and function of the airway epithelium that is crucial for lung homeostasis and host defense. The aim of this study was therefore to determine age-related differences in structural and functional properties of primary nasal epithelial cultures from healthy children and non-smoking elderly people. To achieve this goal, highly differentiated nasal epithelial cultures were established from nasal brushes at air–liquid interface and used to study epithelial cell type composition, mucin (MUC5AC and MUC5B) expression, and ion transport properties. Furthermore, we determined age-dependent molecular signatures using global proteomic analysis. We found lower numeric densities of ciliated cells and higher levels of MUC5AC expression in cultures from children vs. elderly people. Bioelectric studies showed no differences in basal ion transport properties, ENaC-mediated sodium absorption, or CFTR-mediated chloride transport, but detected decreased calcium-activated TMEM16A-mediated chloride secretory responses in cultures from children vs. elderly people. Proteome analysis identified distinct age-dependent molecular signatures associated with ciliation and mucin biosynthesis, as well as other pathways implicated in aging. Our data identified intrinsic, age-related differences in structure and function of the nasal epithelium and provide a basis for further studies on the role of these findings in age-dependent airways disease phenotypes observed with a spectrum of respiratory infections and other noxious stimuli.

鼻上皮（nasal epithelium）是抵御吸入病原体、过敏原与刺激物的第一道防线，在一系列急慢性气道疾病的发病机制中发挥关键作用。尽管此类有害刺激可诱发年龄依赖性临床表型，但目前对于衰老如何影响气道上皮的结构与功能——这一过程对肺稳态与宿主防御至关重要——仍知之甚少。因此本研究旨在明确健康儿童与非吸烟老年人的原代鼻上皮培养物在结构与功能特性上的年龄相关差异。为达成研究目标，研究人员通过鼻刷样本在气液界面（air-liquid interface）上构建了高分化鼻上皮培养物，用于分析上皮细胞类型组成、MUC5AC与MUC5B黏蛋白的表达水平以及离子转运特性。此外，本研究通过全局蛋白质组学分析确定了年龄依赖性分子特征。研究结果显示，与老年人的培养物相比，儿童培养物中的纤毛细胞数量密度更低，而MUC5AC的表达水平更高。生物电学研究表明，两组的基础离子转运特性、上皮钠通道（ENaC）介导的钠吸收以及囊性纤维化跨膜传导调节因子（CFTR）介导的氯离子转运均无显著差异，但儿童培养物中钙激活TMEM16A介导的氯离子分泌反应有所减弱。蛋白质组分析鉴定出了与纤毛发生、黏蛋白生物合成以及其他衰老相关通路密切相关的独特年龄依赖性分子特征。本研究揭示了鼻上皮结构与功能的内在年龄相关差异，为进一步探究此类发现在一系列呼吸道感染与其他有害刺激所引发的年龄依赖性气道疾病表型中的作用提供了重要研究基础。