Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands.
Nephrol Dial Transplant. 2023 Jun 30;38(7):1583-1590. doi: 10.1093/ndt/gfac235.
Tubular transport is a key function of the kidney to maintain electrolyte and acid-base homeostasis. Urinary extracellular vesicles (uEVs) harbor water, electrolyte, and acid-base transporters expressed at the apical plasma membrane of tubular epithelial cells. Within the uEV proteome, the correlations between kidney and uEV protein abundances are strongest for tubular transporters. Therefore, uEVs offer a noninvasive approach to probing tubular transport in health and disease. Here, we review how kidney tubular physiology is reflected in uEVs and, conversely, how uEVs may modify tubular transport. Clinically, uEV tubular transporter profiling has been applied to rare diseases, such as inherited tubulopathies, but also to more common conditions, such as hypertension and kidney disease. Although uEVs hold the promise to advance the diagnosis of kidney disease to the molecular level, several biological and technical complexities must still be addressed. The future will tell whether uEV analysis will mainly be a powerful tool to study tubular physiology in humans or whether it will move forward to become a diagnostic bedside test.
管状运输是肾脏维持电解质和酸碱平衡的关键功能。尿细胞外囊泡（uEVs）包含水、电解质和酸碱转运体，这些转运体表达在管状上皮细胞的顶质膜上。在 uEV 蛋白质组中，肾脏和 uEV 蛋白丰度之间的相关性最强的是管状转运体。因此，uEV 提供了一种非侵入性的方法来探测健康和疾病中的管状运输。在这里，我们回顾了肾脏管状生理学如何反映在 uEV 中，以及 uEV 如何反过来改变管状运输。临床上，uEV 管状转运体分析已应用于罕见疾病，如遗传性肾小管病，但也应用于更常见的疾病，如高血压和肾脏病。尽管 uEV 有希望将肾脏病的诊断推进到分子水平，但仍有几个生物学和技术上的复杂性需要解决。未来将告诉我们，uEV 分析是否将主要成为研究人类管状生理学的有力工具，或者是否将进一步发展成为诊断床边测试。
