Phosphodiesterase types 3 and 4 regulate the phasic contraction of neonatal rat bladder smooth myocytes via distinct mechanisms
Phosphodiesterase types 3 and 4 regulate the phasic contraction of neonatal rat bladder smooth myocytes via distinct mechanisms
复制标题
DOI：
10.1016/j.cellsig.2014.01.020
复制
发表时间：
2014-05-01
影响因子：
4.8
通讯作者：
Ji, Guangju
中科院分区：
文献类型：
--
作者：
Zhai, Kui;Chang, Yan;Ji, Guangju
环磷酸腺苷 (cAMP) 通路的激活会降低膀胱收缩力。然而，人们对磷酸二酯酶 (PDE) 家族在调节这一功能中的作用知之甚少。在这里，我们比较了新生大鼠膀胱平滑肌细胞中 cAMP 水解 PDE 的收缩功能。 RT-PCR 和 Western blotting 分析表明，新生大鼠膀胱中表达了 PDE1-4 的几种亚型。虽然 8-甲氧基甲基1-3异丁基-1-甲基黄嘌呤（PDE1 抑制剂）和 BAY-60-7550（PDE2 抑制剂）对卡巴胆碱增强的膀胱条的阶段性收缩没有影响，但西洛酰胺（Cil，PDE3 抑制剂）和 Ro-20-1724（Ro，PDE4 抑制剂）显着 减少这些收缩。 Ro 的这种抑制作用被 PKA 抑制剂 14-89 减弱，而 Cil 的抑制作用被 PKG 抑制剂 KT 5823 强烈减弱。在单个膀胱平滑肌细胞中应用 Ro 导致 Ca2+ 火花频率增加，但 Ca2+ 瞬变和肌浆网 (SR) Ca2+ 含量降低。相比之下，西尔对这些事件没有任何影响。此外，Ro 诱导的阶段性收缩抑制被兰尼定和伊贝里奥毒素显着阻断。总的来说，PDE3 和 PDE4 是维持膀胱平滑肌细胞阶段性收缩的主要 PDE 同工型，其中 PDE4 的功能比 PDE3 更活跃。然而，它们的作用是通过不同的机制来调节的。 (c) 2014 爱思唯尔公司保留所有权利。
Activation of the cyclic AMP (cAMP) pathway reduces bladder contractility. However, the role of phosphodiesterase (PDE) families in regulating this function is poorly understood. Here, we compared the contractile function of the cAMP hydrolyzing PDEs in neonatal rat bladder smooth myocytes. RT-PCR and Western blotting analysis revealed that several isoforms of PDE1-4 were expressed in neonatal rat bladder. While 8-methoxymethy1-3isobutyl-1-methylxanthine (a PDE1 inhibitor) and BAY-60-7550 (a PDE2 inhibitor) had no effect on the carbachol-enhanced phasic contractions of bladder strips, cilostamide (Cil, a PDE3 inhibitor) and Ro-20-1724 (Ro, a PDE4 inhibitor) significantly reduced these contractions. This inhibitory effect of Ro was blunted by the PKA inhibitor 14-89, while the inhibitory effect of Cil was strongly attenuated by the PKG inhibitor KT 5823. Application of Ro in single bladder smooth myocytes resulted in an increase in Ca2+ spark frequency but a decrease both in Ca2+ transients and in sarcoplasmic reticulum (SR) Ca2+ content. In contrast, Cil had no effect on these events. Furthermore, Ro-induced inhibition of the phasic contractions was significantly blocked by ryanodine and iberiotoxin. Taken together, PDE3 and PDE4 are the main PDE isoforms in maintaining the phasic contractions of bladder smooth myocytes, with PDE4 being functionally more active than PDE3. However, their roles are mediated through different mechanisms. (c) 2014 Elsevier Inc All rights reserved.