Colocalization of the (Pro)renin Receptor/Atp6ap2 with H+-ATPases in Mouse Kidney but Prorenin Does Not Acutely Regulate Intercalated Cell H+-ATPase Activity.
Colocalization of the (Pro)renin Receptor/Atp6ap2 with H+-ATPases in Mouse Kidney but Prorenin Does Not Acutely Regulate Intercalated Cell H+-ATPase Activity.
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DOI：
10.1371/journal.pone.0147831
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Wagner CA
中科院分区：
文献类型：
--
作者：
Daryadel A;Bourgeois S;Figueiredo MF;Gomes Moreira A;Kampik NB;Oberli L;Mohebbi N;Lu X;Meima ME;Danser AH;Wagner CA
(Pro)肾素受体(P)RR/Atp6ap2是一种细胞表面蛋白，能够结合和非蛋白水解性激活前肾素。此外，(P)RR与H+-ATPase相关，在H+-ATPase调节和Wnt信号转导中的替代功能已有报道。肾脏表达非常高水平的H+-ATPase，参与多种功能，如内吞作用、膜蛋白循环以及尿酸、碳酸氢盐重吸收和盐分吸收。在这里，我们想要沿着小鼠肾单位定位(P)RR/Atp6ap2，以研究(P)RR/Atp6ap2是否与其他H+-ATPase亚基协同调节，以及(P)RR/Atp6ap2与Prorenin急性刺激是否调节新分离的集合管中插入细胞的H+-ATPase活性。我们用定量聚合酶链式反应和免疫组织化学方法将(P)PR/Atp6ap2定位于小鼠肾单位。(P)所有肾单位节段均可检测到RR/Atp6ap2基因的表达，其中收集系统中RR/Atp6ap2的表达水平最高，与H+-ATPase的表达一致。进一步的实验表明，在近端小管的刷状缘膜和与H+-ATPase共定位的所有类型的插入细胞中都有表达。在NH4Cl、NaHCO3、KHCO3、氯化钠或矿物皮质激素DOCA处理7天的小鼠中，(P)RR/Atp6ap2和H+-ATPase亚基在蛋白质和mRNA水平上被调节，但不是共同调节。在对照组、NH4Cl或NaHCO3处理的小鼠肾脏中，PRR/Atp6ap2总是与H+-ATPase亚基共存于近端小管的刷状缘膜、A型间质细胞的顶极以及非A型间质细胞的基底侧膜和/或顶膜。离体脑集合管的微灌流和腔内应用普罗瑞宁对H+-ATPase活性无明显刺激作用。然而，分离的集合管与Prorenin孵育并未显著增加ERK1/2的磷酸化。我们的结果提示PRR/Atp6ap2在近端小管和间质细胞中可能与H+-ATPase形成复合体，而Prorenin对间质细胞中的H+-ATPase活性没有明显影响。
The (Pro)renin receptor (P)RR/Atp6ap2 is a cell surface protein capable of binding and non-proteolytically activate prorenin. Additionally, (P)RR is associated with H+-ATPases and alternative functions in H+-ATPase regulation as well as in Wnt signalling have been reported. Kidneys express very high levels of H+-ATPases which are involved in multiple functions such as endocytosis, membrane protein recycling as well as urinary acidification, bicarbonate reabsorption, and salt absorption. Here, we wanted to localize the (P)RR/Atp6ap2 along the murine nephron, exmaine whether the (P)RR/Atp6ap2 is coregulated with other H+-ATPase subunits, and whether acute stimulation of the (P)RR/Atp6ap2 with prorenin regulates H+-ATPase activity in intercalated cells in freshly isolated collecting ducts. We localized (P)PR/Atp6ap2 along the murine nephron by qPCR and immunohistochemistry. (P)RR/Atp6ap2 mRNA was detected in all nephron segments with highest levels in the collecting system coinciding with H+-ATPases. Further experiments demonstrated expression at the brush border membrane of proximal tubules and in all types of intercalated cells colocalizing with H+-ATPases. In mice treated with NH4Cl, NaHCO3, KHCO3, NaCl, or the mineralocorticoid DOCA for 7 days, (P)RR/Atp6ap2 and H+-ATPase subunits were regulated but not co-regulated at protein and mRNA levels. Immunolocalization in kidneys from control, NH4Cl or NaHCO3 treated mice demonstrated always colocalization of PRR/Atp6ap2 with H+-ATPase subunits at the brush border membrane of proximal tubules, the apical pole of type A intercalated cells, and at basolateral and/or apical membranes of non-type A intercalated cells. Microperfusion of isolated cortical collecting ducts and luminal application of prorenin did not acutely stimulate H+-ATPase activity. However, incubation of isolated collecting ducts with prorenin non-significantly increased ERK1/2 phosphorylation. Our results suggest that the PRR/Atp6ap2 may form a complex with H+-ATPases in proximal tubule and intercalated cells but that prorenin has no acute effect on H+-ATPase activity in intercalated cells.