EGF Receptor Inhibition by Erlotinib Increases Aquaporin 2-Mediated Renal Water Reabsorption
EGF Receptor Inhibition by Erlotinib Increases Aquaporin 2-Mediated Renal Water Reabsorption
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DOI：
10.1681/asn.2015080903
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发表时间：
2016-10-01
影响因子：
13.6
通讯作者：
Bouley, Richard
中科院分区：
文献类型：
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作者：
Cheung, Pui W.;Nomura, Naohiro;Bouley, Richard
肾源性尿崩症(NDI)是由血管加压素(VP)受体2型信号通路受损引起的。由于针对典型的VP/cAMP/蛋白激酶A途径的NDI的潜在治疗方法到目前为止被证明是无效的，因此已经寻找了调节水通道蛋白2(AQP2)运输的替代策略。我们的高通量化学筛选试验成功鉴定了化合物，促使我们确定EGF受体(EGFR)抑制剂是否刺激AQP2转运和减少尿量。选择性EGFR抑制剂厄洛替尼可增强集合管主细胞AQP2的表达，使锂致NDI小鼠的尿量减少45%。与VP相似，厄洛替尼使LLC-PK1细胞胞吐增加，内吞减少，导致AQP2膜积聚显著增加。厄洛替尼增加AQP2在Ser-256和Ser-269的磷酸化，降低Ser-261的磷酸化，并呈剂量依赖关系。然而，与VP不同的是，Erlotinib的作用不依赖于cAMP、cGMP和蛋白激酶A。相反，EGF降低了VP诱导的AQP2Ser-256的磷酸化，提示VP和EGF在AQP2转运过程中存在串扰，EGF在水稳态中起作用。这些结果揭示了一条有助于调节AQP2介导的水重吸收的新途径，并为NDI的治疗提供了新的潜在治疗策略。
Nephrogenic diabetes insipidus (NDI) is caused by impairment of vasopressin (VP) receptor type 2 signaling. Because potential therapies for NDI that target the canonical VP/cAMP/protein kinase A pathway have so far proven ineffective, alternative strategies for modulating aquaporin 2 (AQP2) trafficking have been sought. Successful identification of compounds by our high-throughput chemical screening assay prompted us to determine whether EGF receptor (EGFR) inhibitors stimulate AQP2 trafficking and reduce urine output. Erlotinib, a selective EGFR inhibitor, enhanced AQP2 apical membrane expression in collecting duct principal cells and reduced urine volume by 45% after 5 days of treatment in mice with lithium induced NDI. Similar to VP, erlotinib increased exocytosis and decreased endocytosis in LLC-PK1 cells, resulting in a significant increase in AQP2 membrane accumulation. Erlotinib increased phosphorylation of AQP2 at Ser-256 and Ser-269 and decreased phosphorylation at Ser-261 in a dose-dependent manner. However, unlike VP, the effect of erlotinib was independent of cAMP, cGMP, and protein kinase A. Conversely, EGF reduced VP-induced AQP2 Ser-256 phosphorylation, suggesting crosstalk between VP and EGF in AQP2 trafficking and a role of EGF in water homeostasis. These results reveal a novel pathway that contributes to the regulation of AQP2-mediated water reabsorption and suggest new potential therapeutic strategies for NDI treatment.