Department of Medicine, University of Kansas Medical Center, Kansas City, Kansas 66160-3018, USA.
Am J Physiol Renal Physiol. 2011 Nov;301(5):F1005-13. doi: 10.1152/ajprenal.00243.2011. Epub 2011 Aug 3.
In autosomal dominant polycystic kidney disease (ADPKD), arginine vasopressin (AVP) accelerates cyst growth by stimulating cAMP-dependent ERK activity and epithelial cell proliferation and by promoting Cl(-)-dependent fluid secretion. Tolvaptan, a V2 receptor antagonist, inhibits the renal effects of AVP and slows cyst growth in PKD animals. Here, we determined the effect of graded concentrations of tolvaptan on intracellular cAMP, ERK activity, cell proliferation, and transcellular Cl(-) secretion using human ADPKD cyst epithelial cells. Incubation of ADPKD cells with 10(-9) M AVP increased intracellular cAMP and stimulated ERK and cell proliferation. Tolvaptan caused a concentration-dependent inhibition of AVP-induced cAMP production with an apparent IC(50) of ∼10(-10) M. Correspondingly, tolvaptan inhibited AVP-induced ERK signaling and cell proliferation. Basolateral application of AVP to ADPKD cell monolayers grown on permeable supports caused a sustained increase in short-circuit current that was completely blocked by the Cl(-) channel blocker CFTR(inh-172), consistent with AVP-induced transepithelial Cl(-) secretion. Tolvaptan inhibited AVP-induced Cl(-) secretion and decreased in vitro cyst growth of ADPKD cells cultured within a three-dimensional collagen matrix. These data demonstrate that relatively low concentrations of tolvaptan inhibit AVP-stimulated cell proliferation and Cl(-)-dependent fluid secretion by human ADPKD cystic cells.
在常染色体显性多囊肾病 (ADPKD) 中，精氨酸加压素 (AVP) 通过刺激 cAMP 依赖性 ERK 活性和上皮细胞增殖以及促进 Cl(-) 依赖性液体分泌来加速囊肿生长。托伐普坦是一种 V2 受体拮抗剂，可抑制 AVP 的肾脏作用并减缓 PKD 动物的囊肿生长。在这里，我们使用人 ADPKD 囊肿上皮细胞确定了托伐普坦的不同浓度对细胞内 cAMP、ERK 活性、细胞增殖和跨细胞 Cl(-)分泌的影响。用 10(-9) M AVP 孵育 ADPKD 细胞会增加细胞内 cAMP 并刺激 ERK 和细胞增殖。托伐普坦对 AVP 诱导的 cAMP 产生具有浓度依赖性抑制作用，表观 IC(50)约为 10(-10) M。相应地，托伐普坦抑制 AVP 诱导的 ERK 信号传导和细胞增殖。AVP 施加于在可渗透支持物上生长的 ADPKD 细胞单层的基底外侧会引起短路电流的持续增加，该增加完全被 Cl(-)通道阻滞剂 CFTR(inh-172)阻断，与 AVP 诱导的跨上皮 Cl(-)分泌一致。托伐普坦抑制 AVP 诱导的 Cl(-)分泌并减少在三维胶原基质中培养的 ADPKD 细胞的体外囊肿生长。这些数据表明，相对较低浓度的托伐普坦抑制 AVP 刺激的人 ADPKD 囊性细胞的增殖和 Cl(-)依赖性液体分泌。
