Aging and senescence-associated signatures of aged kidney glomerular cells [bulk RNA-seq]

The kidney governs many physiological factors of the body, and the glomerulus is its core filtration unit. Glomeruli comprise of less than 1.5% of the kidneys volume and thus are underrepresented in many analyses of the kidney, and require particular isolation methods. Aging is a major risk factor for kidney disease, yet despite the importance of proper glomerular function, we have limited knowledge of the changes that glomerular cells undergo during aging. Here we interrogate the aged mouse kidney, glomerulus and glomerular cells using various approaches, including single cell RNA sequencing (scRNA-Seq), to identify age and senescence associated changes at the tissue and cellular level. We show that the aged kidney and glomerulus undergo structural changes, including increased fibrosis, glomerulonephritis and expression of injury and senescence-associated markers. Lastly, we utilized our method for high-throughput analysis of mouse glomeruli to characterize cell-specific and age-related changes in glomerular cells. This analysis revealed a senescence-associated phenotype in aged mesangial cells, and emphasized the potential importance of mesangial cells and macrophages in this niche. Our study provides insights into the molecular and cellular changes of the aging glomerulus that suggest therapeutic targets for age-related renal dysfunction. Isolated kidney glomeruli were isolated from young and old mice for bulk RNA sequencing.肾脏调控机体诸多生理功能，肾小球是其核心滤过单元。肾小球占肾脏体积比例不足1.5%，因此在诸多肾脏相关分析中代表性不足，且需要特殊的分离方法。衰老是肾脏疾病的主要危险因素之一，尽管肾小球功能正常至关重要，但我们对于衰老过程中肾小球细胞所发生的变化仍知之甚少。本研究通过包括单细胞RNA测序（single cell RNA sequencing, scRNA-Seq）在内的多种方法，对衰老小鼠的肾脏、肾小球及肾小球细胞进行探究，以在组织与细胞层面识别与年龄及衰老相关的变化。研究发现衰老肾脏与肾小球会发生结构改变，包括纤维化程度升高、肾小球肾炎，以及损伤与衰老相关标志物的表达上调。最后，我们利用所建立的小鼠肾小球高通量分析方法，对肾小球细胞的细胞特异性及年龄相关变化进行表征。该分析揭示了衰老系膜细胞中存在衰老相关表型，并强调了系膜细胞与巨噬细胞在该微环境中的潜在重要性。本研究为衰老肾小球的分子与细胞变化提供了新见解，为年龄相关性肾功能障碍的治疗靶点提供了参考方向。本研究从年轻与老年小鼠体内分离肾脏肾小球，用于批量RNA测序。