Abnormal Na+/H+ antiporter phenotype and turnover of immortalized lymphoblasts from type 1 diabetic patients with nephropathy.
Abnormal Na+/H+ antiporter phenotype and turnover of immortalized lymphoblasts from type 1 diabetic patients with nephropathy.
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1 型糖尿病肾病患者的永生化淋巴母细胞异常 Na /H 逆向转运表型和周转。
DOI：
10.1172/jci117291
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Krolewski,AS
中科院分区：
文献类型：
--
作者：
Ng,LL;Davies,JE;Siczkowski,M;Sweeney,FP;Quinn,PA;Krolewski,B;Krolewski,AS
1 型糖尿病肾病患者和原发性高血压患者的细胞 Na+/H+ 交换器 (NHE) 活性升高。高血压患者的这种 NHE 表型特征（Vmax 升高和 Hill 系数降低）保留在来自高血压患者的 Epstein-Barr 病毒转化的淋巴母细胞中。在本研究中，我们使用 pH 指示剂 2,7'-双-(羧乙基)-5,6-羧基荧光素进行荧光测定，并使用特异性多克隆抗体估计 NHE 亚型 1 (NHE-1) 密度，确定了患有和不患有肾病的糖尿病患者以及非糖尿病对照的培养淋巴母细胞的 NHE 动力学。与正常对照和正常白蛋白尿的糖尿病患者相比，糖尿病肾病患者细胞中 NHE 的 Vmax 显着升高，内部 H+ 结合的 Hill 系数降低。通过蛋白质印迹法测量的 NHE-1 密度在所有组中相似。因此，肾病患者细胞中 NHE-1 的周转数升高。糖尿病肾病患者细胞中的这种表型与原发性高血压相似，表明此类患者可能有高血压倾向。此外，由于这些变化在体外培养的淋巴母细胞中持续存在，因此这些细胞应该提供细胞培养模型，以进一步明确导致糖尿病肾病 NHE 激活的基本机制。
Cellular Na+/H+ exchanger (NHE) activity is elevated in type 1 diabetic patients with nephropathy and patients with essential hypertension. The characteristics of this NHE phenotype in hypertension (raised Vmax and a lowered Hill coefficient) are preserved in Epstein-Barr virus-transformed lymphoblasts from hypertensive patients. In this study, we have determined NHE kinetics in cultured lymphoblasts from diabetic patients with and without nephropathy, with nondiabetic controls, using fluorometry with the pH indicator 2,7'-bis-(carboxyethyl)-5,6-carboxyfluorescein and estimation of NHE isoform 1 (NHE-1) density with specific polyclonal antibodies. The Vmax of NHE was elevated significantly, and the Hill coefficient for internal H+ binding was lowered in cells from patients with diabetic nephropathy compared with both normal controls and normoalbuminuric diabetic patients. NHE-1 density as measured by Western blotting was similar in all groups. The turnover number of NHE-1 was thus elevated in cells from nephropathy patients. This phenotype in cells from diabetic nephropathy patients resembles that in essential hypertension and suggests that such patients may have a predisposition to hypertension. Moreover, as these changes persist in cultured lymphoblasts in vitro, these cells should provide a cell culture model to further define the basic mechanisms leading to NHE activation in diabetic nephropathy.Images