Activation of cGMP-dependent protein kinase stimulates cardiac ATP-sensitive potassium channels via a ROS/calmodulin/CaMKII signaling cascade.
Activation of cGMP-dependent protein kinase stimulates cardiac ATP-sensitive potassium channels via a ROS/calmodulin/CaMKII signaling cascade.
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DOI：
10.1371/journal.pone.0018191
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发表时间：
2011-03-29
期刊：
影响因子：
3.7
通讯作者：
Lin YF
中科院分区：
文献类型：
--
作者：
Chai Y;Zhang DM;Lin YF
环GMP（cGMP）依赖性蛋白激酶（PKG）被认为是多种细胞类型中的重要信号组分。PKG可能影响心脏ATP敏感性钾（KATP）通道的功能，KATP通道是心脏应激适应的关键离子通道;然而，其潜在机制仍不清楚。本研究就是为了解决这一问题。使用转染的人胚肾（HEK）293细胞和兔心室心肌细胞，在细胞附着和由内而外的贴片配置中进行心脏KATP通道的单通道记录。我们发现，Kir6.2/SUR 2A（心脏型KATP）通道激活cGMP选择性磷酸二酯酶抑制剂扎匹司特在浓度依赖性的方式在细胞贴附补丁从HEK 293细胞，模仿膜渗透性cGMP类似物8-溴-cGMP，而取消选择性PKG抑制剂的效果。有趣的是，直接应用PKG适度减少，而不是增强Kir6.2/SUR 2A单通道电流切除，内面向外补丁。此外，PKG刺激的Kir6.2/SUR 2A通道在完整的细胞被废除ROS/H2 O2清除，拮抗钙调蛋白，钙/钙调蛋白依赖性蛋白激酶II（CaMK II）的封锁，分别。外源性H2 O2也浓度依赖性地刺激完整细胞中的Kir6.2/SUR 2A通道，其作用被钙调蛋白或CaMKII的抑制所阻止。在完整的心室心肌细胞中证实了PKG对KATP通道的刺激，这是ROS和CaMKII依赖性的。动力学上，PKG似乎刺激这些通道的不稳定的最长的关闭状态，同时稳定的长期开放状态，并促进开放过渡。本研究提供了新的证据表明PKG对心脏KATP通道发挥双重调节作用，包括由ROS（特别是H2 O2），钙调蛋白和CaMKII介导的细胞内信号传导引起的显著刺激，以及可能由通道或一些密切相关蛋白的直接PKG磷酸化介导的中度通道抑制。cGMP/PKG/ROS/CaM/CaMKII信号通路可能通过开放KATP通道调节心肌细胞兴奋性，对心肌缺血再灌注损伤具有保护作用。
Cyclic GMP (cGMP)-dependent protein kinase (PKG) is recognized as an important signaling component in diverse cell types. PKG may influence the function of cardiac ATP-sensitive potassium (KATP) channels, an ion channel critical for stress adaptation in the heart; however, the underlying mechanism remains largely unknown. The present study was designed to address this issue. Single-channel recordings of cardiac KATP channels were performed in both cell-attached and inside-out patch configurations using transfected human embryonic kidney (HEK)293 cells and rabbit ventricular cardiomyocytes. We found that Kir6.2/SUR2A (the cardiac-type KATP) channels were activated by cGMP-selective phosphodiesterase inhibitor zaprinast in a concentration-dependent manner in cell-attached patches obtained from HEK293 cells, an effect mimicked by the membrane-permeable cGMP analog 8-bromo-cGMP whereas abolished by selective PKG inhibitors. Intriguingly, direct application of PKG moderately reduced rather than augmented Kir6.2/SUR2A single-channel currents in excised, inside-out patches. Moreover, PKG stimulation of Kir6.2/SUR2A channels in intact cells was abrogated by ROS/H2O2 scavenging, antagonism of calmodulin, and blockade of calcium/calmodulin-dependent protein kinase II (CaMKII), respectively. Exogenous H2O2 also concentration-dependently stimulated Kir6.2/SUR2A channels in intact cells, and its effect was prevented by inhibition of calmodulin or CaMKII. PKG stimulation of KATP channels was confirmed in intact ventricular cardiomyocytes, which was ROS- and CaMKII-dependent. Kinetically, PKG appeared to stimulate these channels by destabilizing the longest closed state while stabilizing the long open state and facilitating opening transitions. The present study provides novel evidence that PKG exerts dual regulation of cardiac KATP channels, including marked stimulation resulting from intracellular signaling mediated by ROS (H2O2 in particular), calmodulin and CaMKII, alongside of moderate channel suppression likely mediated by direct PKG phosphorylation of the channel or some closely associated proteins. The novel cGMP/PKG/ROS/calmodulin/CaMKII signaling pathway may regulate cardiomyocyte excitability by opening KATP channels and contribute to cardiac protection against ischemia-reperfusion injury.
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DOI：
10.1073/pnas.1834314100
发表时间：
2003-09-30
影响因子：
11.1
作者：
Avshalumov, MV;Rice, ME
通讯作者：
Rice, ME
影响因子：
5
作者：
Ichinari, K;Kakei, M;Tanaka, H
通讯作者：
Tanaka, H
影响因子：
14.9
作者：
Jordan, M;Schallhorn, A;Wurm, FM
通讯作者：
Wurm, FM
影响因子：
5.5
作者：
Krippeit-Drews, P;Krämer, C;Drews, G
通讯作者：
Drews, G
影响因子：
15.9
作者：
GOLDHABER, JI;JI, S;WEISS, JN
通讯作者：
WEISS, JN