A bell‐shaped pattern of urinary aquaporin‐2‐bearing extracellular vesicle release in an experimental model of nephronophthisis
A bell‐shaped pattern of urinary aquaporin‐2‐bearing extracellular vesicle release in an experimental model of nephronophthisis
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DOI：
10.14814/phy2.14092
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发表时间：
2019-05
影响因子：
2.5
通讯作者：
N. Mikoda;Hiroko Sonoda;Sayaka Oshikawa;Y. Hoshino;T. Matsuzaki;M. Ikeda
中科院分区：
文献类型：
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作者：
N. Mikoda;Hiroko Sonoda;Sayaka Oshikawa;Y. Hoshino;T. Matsuzaki;M. Ikeda
DBA/2-FG pcy (pcy) 小鼠是人类肾痨（一种隐性囊性肾病）的模型。水通道蛋白-2 (AQP2)（一种水通道蛋白）的肾脏表达已被证明在 pcy 小鼠中发生改变。然而，在 pcy 小鼠中，肾表达与其在尿细胞外囊泡 (uEV-AQP2) 中的释放之间的关系仍然很大程度上未知，uEV-AQP2 占尿 AQP2 的大部分。在这项研究中，我们在 pcy 小鼠中检查了这种关系与年龄相关的变化。与对照小鼠相比，14周龄后的pcy小鼠表现出尿浓缩能力缺陷，尿量增加。有趣的是，uEV-AQP2 的释放逐渐增加，直至 16 周龄，但在 21 周时，释放量与对照小鼠没有显着差异（即明显的钟形模式）。 uEV 标记蛋白也获得了类似的结果，包括肿瘤易感基因 101 (TSG101) 蛋白和凋亡相关基因 2 相互作用蛋白 X (Alix)。免疫印迹分析显示，肾 AQP2 表达从 11 周开始逐渐增加，免疫组织化学显示这种增加可能是由于 AQP2 阳性细胞数量增加所致。对肾脏中表达的七种 AQP mRNA 的分析支持了这一观点。这些数据表明 uEV-AQP2 的水平并不仅仅反映 AQP2 的肾脏表达，而且 pcy 小鼠中 uEV-AQP2 释放的改变取决于肾脏 AQP2 阳性细胞和释放到尿液中的 EV 的数量。
The DBA/2‐FG pcy (pcy) mouse is a model of human nephronophthisis, a recessive cystic kidney disease. Renal expression of aquaporin‐2 (AQP2), a water channel protein, has been shown to be altered in pcy mice. However, the relationship between the renal expression and its release in urinary extracellular vesicles (uEV‐AQP2), which account for most urinary AQP2, in pcy mice has remained largely unknown. In this study, we examined age‐related alterations of this relationship in pcy mice. In comparison with control mice, pcy mice after the age of 14 weeks showed defective urinary concentration ability with an increase in urinary volume. Interestingly, the release of uEV‐AQP2 increased progressively up to the age of 16 weeks, but at 21 weeks the release did not significantly differ from that in control mice (i.e., a bell‐shaped pattern was evident). Similar results were obtained for uEV marker proteins, including tumor susceptibility gene 101 (TSG101) protein and apoptosis‐linked gene 2‐interacting protein X (Alix). Immunoblot analysis revealed that renal AQP2 expression increased progressively from 11 weeks, and immunohistochemistry showed that this increase was possibly due to an increase in the number of AQP2‐positive cells. Analysis of mRNAs for seven types of AQP expressed in the kidney supported this notion. These data suggest that the level of uEV‐AQP2 does not simply mirror the renal expression of AQP2 and that the altered release of uEV‐AQP2 in pcy mice depends on the numbers of both renal AQP2‐positive cells and EVs released into the urine.