Endogenous concentrations of ouabain act as a cofactor to stimulate fluid secretion and cyst growth of in vitro ADPKD models via cAMP and EGFR-Src-MEK pathways
Endogenous concentrations of ouabain act as a cofactor to stimulate fluid secretion and cyst growth of in vitro ADPKD models via cAMP and EGFR-Src-MEK pathways
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DOI：
10.1152/ajprenal.00677.2011
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发表时间：
2012-10-01
影响因子：
4.2
通讯作者：
Blanco, Gustavo
中科院分区：
文献类型：
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作者：
Jansson, Kyle;Nguyen, Anh-Nguyet T.;Blanco, Gustavo
Jansson K，Nguyen AT，Magenheimer BS，Reif GA，Aramadhaka LR，Bello-Reuss E，Wallace DP，Calvet JP，布兰科G.哇巴因的内源性浓度作为辅因子通过cAMP和EGFR-SRC-MEK途径刺激体外ADPKD模型的液体分泌和囊肿生长。美国肾脏生理学杂志303：F982-F990，2012年。首次发表于2012年8月1日; doi：10.1152/ajprenal.00677.2011。在常染色体显性多囊肾病（ADPKD）中，肾囊肿是由上皮细胞异常增殖和经上皮液体分泌引起的。我们先前表明，哇巴因通过刺激EGF受体（EGFR）-Src-MEK/ERK信号通路增加培养的人ADPKD细胞的增殖。我们研究哇巴因是否影响液体分泌和体外囊肿生长的人ADPKD细胞单层，ADPKD细胞微囊培养的三维胶原基质，和后肾器官培养Pkd（1 m1 Bei）小鼠。哇巴因单独的生理浓度不影响ADPKD单层或培养的ADPKD微囊的生长中的净经上皮基底到顶端的液体运输。与此相反，在存在毛喉素或8-溴-cAMP，哇巴因显着增强ADPKD液体分泌和微囊扩张。哇巴因通过CFTR增强cAMP依赖性Cl-分泌来发挥这种作用。同样，哇巴因加速Pkd（1 m1 Bei）小鼠后肾cAMP依赖性囊肿扩大，纯合子小鼠比杂合子小鼠反应更明显。哇巴因对正常人肾细胞的液体分泌和囊性形成没有影响，并且在野生型小鼠肾脏中仅引起轻微的囊性扩张。哇巴因对ADPKD细胞和Pkd（1 m1 Bei）后肾的作用可被EGFR（AG 1478）、Src（PP 2）和MEK（U 0126）抑制剂所阻断。总之，我们的研究结果表明，哇巴因，在生理浓度下使用，通过激活EGFR-Src-MEK途径，对cAMP介导的液体分泌和囊肿生长具有协同作用。这些数据为哇巴因作为一种内源性激素加剧ADPKD囊肿进展的作用提供了重要证据。
Jansson K, Nguyen AT, Magenheimer BS, Reif GA, Aramadhaka LR, Bello-Reuss E, Wallace DP, Calvet JP, Blanco G. Endogenous concentrations of ouabain act as a cofactor to stimulate fluid secretion and cyst growth of in vitro ADPKD models via cAMP and EGFR-SRC-MEK pathways. Am J Physiol Renal Physiol 303: F982-F990, 2012. First published August 1, 2012; doi:10.1152/ajprenal.00677.2011.-In autosomal-dominant polycystic kidney disease ( ADPKD), renal cysts develop by aberrant epithelial cell proliferation and transepithelial fluid secretion. We previously showed that ouabain increases proliferation of cultured human ADPKD cells via stimulation of the EGF receptor (EGFR)-Src-MEK/ERK signaling pathway. We examined whether ouabain affects fluid secretion and in vitro cyst growth of human ADPKD cell monolayers, ADPKD cell microcysts cultured in a three-dimensional collagen matrix, and metanephric organ cultures from Pkd(1m1Bei) mice. Physiological concentrations of ouabain alone did not affect net transepithelial basal-to-apical fluid transport in ADPKD monolayers or growth of cultured ADPKD microcysts. In contrast, in the presence of forskolin or 8-bromo-cAMP, ouabain significantly enhanced ADPKD fluid secretion and microcyst expansion. Ouabain exerted this effect by enhancing cAMP-dependent Cl- secretion via the CFTR. Similarly, ouabain accelerated cAMP-dependent cyst enlargement in Pkd(1m1Bei) mice metanephroi, with a more prominent response in homozygous than heterozygous mice. Ouabain had no effect on fluid secretion and cystogenesis of normal human kidney cells and caused only slight cystic dilations in wild-type mouse kidneys. The effects of ouabain in ADPKD cells and Pkd(1m1Bei) metanephroi were prevented by inhibitors of EGFR (AG1478), Src (PP2), and MEK (U0126). Together, our results show that ouabain, used in physiological concentrations, has synergistic effects on cAMP-mediated fluid secretion and cyst growth, via activation of the EGFR-Src-MEK pathway. These data provide important evidence for the role of ouabain as an endogenous hormone that exacerbates ADPKD cyst progression.