Formation of cysts by principal-like MDCK cells depends on the synergy of cAMP- and ATP-mediated fluid secretion
Formation of cysts by principal-like MDCK cells depends on the synergy of cAMP- and ATP-mediated fluid secretion
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DOI：
10.1007/s00109-010-0715-1
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发表时间：
2011-03-01
影响因子：
4.7
通讯作者：
Eckardt, Kai-Uwe
中科院分区：
文献类型：
--
作者：
Buchholz, Bjoern;Teschemacher, Barbara;Eckardt, Kai-Uwe
有人提出，常染色体显性多囊肾病 (ADPKD) 患者中超过 70% 的肾囊肿源自集合管，并且该段内的囊肿几乎完全源自主细胞而非闰细胞。主细胞的这种倾向的机制迄今为止仍然难以捉摸。因此，我们在三维体外模型中使用类似于主细胞和α嵌入细胞的Madin-Darby犬肾（MDCK）亚克隆来确定囊肿发生和囊肿生长的差异，包括对环磷酸腺苷（cAMP）升高的反应和对ATP信号传导的依赖性。我们发现体外囊肿仅由主细胞样 MDCK 细胞克隆发育而来，而不是由闰样 MDCK 细胞克隆发育而来。这种特异性可以在富含主细胞或闰样细胞的混合 MDCK 培养物中得到验证。细胞内 cAMP 升高后的体外囊肿生长主要是由液体分泌驱动的，而不是细胞增殖的增加。研究发现，cAMP 依赖性液体分泌依赖于细胞外 5'-三磷酸腺苷 (ATP)，并与嘌呤能信号传导协同作用，因为使用 ATP 清除剂腺苷三磷酸双磷酸酶以及 P2 受体抑制剂苏拉明可减少 cAMP 驱动的液体分泌，同时增加细胞外 ATP 增强 cAMP 介导的囊肿生长。总之，我们基于 cAMP 和 ATP 信号传导在增强顶端液体分泌方面的协同作用，提供了主细胞而不是嵌入细胞形成囊肿的能力的体外证据。
It has been suggested that more than 70% of the renal cysts in patients with autosomal dominant polycystic kidney disease (ADPKD) arise from the collecting duct and that within this segment cysts originate almost exclusively from principal rather than intercalated cells. The mechanisms for this predisposition of principal cells have so far remained elusive. We, therefore, used Madin-Darby canine kidney (MDCK) subclones resembling principal cells and alpha-intercalated cells in a three-dimensional in vitro model to determine differences in cystogenesis and cyst growth, including the response to cyclic adenosine monophosphate (cAMP) elevation and the dependence on ATP signaling. We found that in vitro cysts developed only from principal-like but not from intercalated-like MDCK cell clones. This specificity could be verified in mixed MDCK cultures enriched for principal- or intercalated-like cells. In vitro cyst growth upon elevation of intracellular cAMP was mainly driven by fluid secretion, rather than increased cell proliferation. The cAMP-dependent fluid secretion was found to depend on extracellular adenosine-5'-triphosphate (ATP) and to act synergistically with purinergic signaling, as the use of the ATP scavenger apyrase, as well as the P2 receptor inhibitor suramin, reduced cAMP-driven fluid secretion, while increasing extracellular ATP potentiated cAMP-mediated cyst growth. In conclusion, we provide in vitro evidence for the ability of principal rather than intercalated cells to form cysts, based on a synergism of cAMP and ATP signaling in enhancing apical fluid secretion.