Hyperphosphorylation of Na-K-2Cl Cotransporter in Thick Ascending Limbs of Dahl Salt-Sensitive Rats
Hyperphosphorylation of Na-K-2Cl Cotransporter in Thick Ascending Limbs of Dahl Salt-Sensitive Rats
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DOI：
10.1161/hypertensionaha.112.202101
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发表时间：
2012-12-01
期刊：
影响因子：
8.3
通讯作者：
Ortiz, Pablo A.
中科院分区：
文献类型：
--
作者：
Ares, Gustavo R.;Haque, Mohammed Z.;Ortiz, Pablo A.
盐敏感型高血压涉及肾脏缺陷，阻止肾脏排出过量的氯化钠。粗大的Henle环上升支通过顶端的Na-K-2Cl协转运蛋白(NKCC2)重新吸收大约30%的过滤后的氯化钠。据报道，在喂食正常盐的Dahl盐敏感大鼠(DSS)的粗大升支中，NKCC2活性和氯重吸收较高。NKCC2的活性主要是通过STE20和SPS1相关的富含脯氨酸和丙氨酸的激酶和氧化应激反应激酶1调节Thr(96)/Thr(101)上的蛋白运输和磷酸化。然而，DSS中NKCC2活性增强的机制尚不清楚。我们推测，与正常食盐饮食的Dahl耐盐大鼠相比，DSS表现出更强的NKCC2转运和更高的NKCC2磷酸化。我们通过表面生物素化和Western印迹检测了NKCC2在Thr(96)和Thr(101)处的稳态表达和磷酸化。与Dahl耐盐大鼠相比，DSS大鼠的表面/总NKCC2比值增加了25%(P
Salt-sensitive hypertension involves a renal defect preventing the kidney from eliminating excess NaCl. The thick ascending limb of Henle loop reabsorbs approximate to 30% of filtered NaCl via the apical Na-K-2Cl cotransporter (NKCC2). Higher NKCC2 activity and Cl reabsorption have been reported in the thick ascending limbs from Dahl salt-sensitive rats (DSS) fed normal salt. NKCC2 activity is primarily regulated by protein trafficking and phosphorylation at Thr(96)/Thr(101) via STE20- and SPS1-related proline and alanine-rich kinases and oxidative stress-responsive kinase 1. However, the mechanism for enhanced NKCC2 activity in DSS is unclear. We hypothesized that DSS exhibit enhanced NKCC2 trafficking and higher NKCC2 phosphorylation compared with Dahl salt-resistant rats on normal salt diet. We measured steady state surface NKCC2 expression and phosphorylation at Thr(96) and Thr(101) by surface biotinylation and Western blot. In DSS, the surface: total NKCC2 ratio was enhanced by 25% compared with Dahl salt-resistant rats (P