Ventricular SK2 upregulation following angiotensin II challenge: Modulation by p21-activated kinase-1
Ventricular SK2 upregulation following angiotensin II challenge: Modulation by p21-activated kinase-1
复制标题
血管紧张素 II 攻击后心室 SK2 上调：p21 激活激酶 1 的调节
DOI：
10.1016/j.yjmcc.2021.11.001
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发表时间：
2022
影响因子：
5
通讯作者：
Xiaoqiu Tan
中科院分区：
文献类型：
--
作者：
Binbin Yang;Qin Jiang;Shicheng He;Tao Li;Xianhong Ou;Tangting Chen;Xuehui Fan;Feng Jiang;Xiaorong Zeng;Christopher L.-H. Huang;Ming Lei;Xiaoqiu Tan
在完整的小鼠心脏、分离的心室肌细胞和新生大鼠心肌细胞（NRCMs）上，探讨肥大刺激对小电导、钙激活的K+（SK 2）通道表达的影响。建立的实验平台在存在和不存在降低的p21激活激酶（PAK 1）（PAK1ckovs.PAK1f/f，或shRNA-PAK 1干扰）表达的情况下应用血管紧张素II（Ang II）激发。SK2电流的贡献，通过其灵敏度检测到的蜂毒肽块。血管紧张素II治疗增加了这种SK2的贡献，光学映射动作电位时程（APD 80）和他们的异质性，和膜片钳电流。与PAK 1f/f、完整心脏和分离的心肌细胞相比，PAK 1cko的这种变化更为明显。它们增加了组织学和超声心动图肥大指数，降低了心肌收缩力，增加了SK 2蛋白表达，PAK 1 ckthan PAK 1f/f的变化相似。在NRCM中，Ang II刺激复制了apamin敏感的SK膜片钳电流以及SK 2 mRNA和蛋白表达和细胞肥大的实时PCR和蛋白质印迹测量的增加。此外，后者通过shRNA-PAK 1干扰增强，并通过PAK 1激动剂FTY 720减轻。CaMKII和CREB磷酸化的增加伴随着这些作用。FTY 720和CaMKII抑制剂KN 93都能挽救这些细胞，但其无活性类似物KN 92却不能。然后在荧光素酶试验中，这种CREB特异性结合KCNN 2启动子序列。这些发现将Ang II诱导的肥大与SK2表达增加相关联，SK2表达增加是由CaMK II/CREB信号传导与PAK 1通路会聚引起的，从而上调KCNN 2启动子活性。SK2可能会影响心脏肥大和衰竭条件下的心脏电生理。
Effects of hypertrophic challenge on small-conductance, Ca2+-activated K+(SK2) channel expression were explored in intact murine hearts, isolated ventricular myocytes and neonatal rat cardiomyocytes (NRCMs). An established experimental platform applied angiotensin II (Ang II) challenge in the presence and absence of reduced p21-activated kinase (PAK1) (PAK1ckovs.PAK1f/f, or shRNA-PAK1 interference) expression. SK2 current contributions were detected through their sensitivity to apamin block. Ang II treatment increased such SK2 contributions to optically mapped action potential durations (APD80) and their heterogeneity, and to patch-clamp currents. Such changes were accentuated inPAK1ckocompared toPAK1f/f, intact hearts and isolated cardiomyocytes. They paralleled increased histological and echocardiographic hypertrophic indices, reduced cardiac contractility, and increased SK2 protein expression, changes similarly greater withPAK1ckothanPAK1f/f. In NRCMs, Ang II challenge replicated such increases in apamin-sensitive SK patch clamp currents as well as in real-time PCR and western blot measures of SK2 mRNA and protein expression and cell hypertrophy. Furthermore, the latter were enhanced by shRNA-PAK1 interference and mitigated by the PAK1 agonist FTY720. Increased CaMKII and CREB phosphorylation accompanied these effects. These were rescued by both FTY720 as well as the CaMKII inhibitor KN93, but not its inactive analogue KN92. Such CREB then specifically bound to theKCNN2promoter sequence in luciferase assays. These findings associate Ang II induced hypertrophy with increased SK2 expression brought about by a CaMKII/CREB signaling convergent with the PAK1 pathway thence upregulating theKCNN2promoter activity. SK2 may then influence cardiac electrophysiology under conditions of cardiac hypertrophy and failure.