Calcium restores a normal proliferation phenotype in human polycystic kidney disease epithelial cells
Calcium restores a normal proliferation phenotype in human polycystic kidney disease epithelial cells
复制标题
DOI：
10.1681/asn.2005060645
复制
发表时间：
2006-01-01
影响因子：
13.6
通讯作者：
Wallace, Darren P.
中科院分区：
文献类型：
--
作者：
Yamaguchi, Tamio;Hempson, Scott J.;Wallace, Darren P.
多囊肾病（PKD）是一种致命性疾病，其特征是肾囊肿进行性扩张。与 PKD 相关的基因突变被认为会破坏细胞内 Ca2+ 调节，导致肾小管上皮细胞异常增殖。 cAMP 刺激 B-Raf/MEK/细胞外信号调节激酶 (B-Raf/MEK/ERK) 通路，并加速从 PKD 囊肿培养的细胞增殖。相比之下，cAMP 抑制正常人肾脏 (NHK) 和 M-1 小鼠集合管细胞的增殖。此前，人们发现，用 Ca2+ 进入阻滞剂处理的 NHK 和 M-1 细胞中细胞内 Ca2+ 水平持续降低，使得 B-Raf/MEK/ERK 通路的 cAMP 激活，从而将细胞转变为 cAMP 生长刺激的表型。在本研究中，使用来自常染色体显性 (ADPKD) 和隐性 (ARPKD) PKD 肾脏的囊肿上皮细胞的原代培养物来确定控制添加 Ca2+ 是否可以逆转 cAMP 的异常促有丝分裂反应。与 NHK 细胞 (77 +/- 2 nM) 相比，囊肿来源的 ADPKD 细胞 (57 +/- 2 nM) 的稳态细胞内 Ca2+ 水平低 20 nM。用 Bay K8644（一种 Ca2+ 通道激活剂）或 A23187（一种 Ca2+ 离子载体）处理 ADPKD 细胞或 ARPKD 细胞，导致细胞内 Ca2+ 水平持续增加，并完全逆转对 cAMP 的促有丝分裂反应。 ADPKD 细胞内 Ca2+ 水平升高会增加 Akt 活性并阻断 cAMP 依赖性 B-Raf 和 ERK 激活。因此，[Ca2+](i) 的增加能够恢复来自两种遗传上不同形式的 PKD 的细胞中对 cAMP 的正常抗有丝分裂反应。
Polycystic kidney disease (PKD) is a lethal disorder characterized by progressive expansion of renal cysts. Genetic mutations associated with PKD are thought to disrupt intracellular Ca2+ regulation, leading to abnormal proliferation of tubule epithelial cells. cAMP stimulates the B-Raf/MEK/extracellular signal-regulated kinase (B-Raf/MEK/ERK) pathway and accelerates the proliferation of cells that are cultured from PKD cysts. By contrast, cAMP inhibits the proliferation of cells from normal human kidneys (NHK) and M-1 mouse collecting duct cells. Previously, it was found that a sustained reduction of intracellular Ca2+ levels in NHK and M-1 cells that were treated with Ca2+ entry blockers allowed cAMP activation of the B-Raf/MEK/ERK pathway, switching the cells to a cAMP-growth stimulated phenotype. In this study, primary cultures of cyst epithelial cells from autosomal dominant (ADPKD) and recessive (ARPKD) PKD kidneys were used to determine whether controlled addition of Ca2+ could reverse the aberrant mitogenic response to cAMP. Steady-state intracellular Ca2+ levels were found to be 20 nM lower in cyst-derived ADPKD cells (57 +/- 2 nM) compared with NHK cells (77 +/- 2 nM). Treatment of ADPKD cells or ARPKD cells with either Bay K8644, a Ca2+ channel activator, or A23187, a Ca2+ ionophore, caused sustained increases in intracellular Ca2+ levels and completely reversed the mitogenic response to cAMP. Elevation of intracellular Ca2+ levels in ADPKD cells increased Akt activity and blocked cAMP-dependent B-Raf and ERK activation. Thus, increases in [Ca2+](i) are able to restore the normal anti-mitogenic response to cAMP in cells that are derived from two genetically distinct forms of PKD.