Reduced Ca2+-calmodulin-dependent protein kinase activity and expression in LV myocardium of dogs with heart failure
Reduced Ca2+-calmodulin-dependent protein kinase activity and expression in LV myocardium of dogs with heart failure
复制标题
DOI：
10.1152/ajpheart.00266.2002
复制
发表时间：
2003-03-01
影响因子：
4.8
通讯作者：
Gupta, RC
中科院分区：
文献类型：
--
作者：
Mishra, S;Sabbah, HN;Gupta, RC
多功能钙调蛋白依赖性蛋白激酶II（CaMKII）在心力衰竭中的作用机制研究有限，且存在争议。本研究在6只心力衰竭（HF）犬（LV射血分数，23 +/- 2%）和6只正常（NL）犬的左心室（LV）心肌中进行。在LV匀浆中，分别使用CaMK II肽和抗体测定CaMK II活性及其蛋白水平。此外，还使用特异性抗体测定LV匀浆中CaM和苏氨酸-17（PLB-Thr（17））和丝氨酸-16（PLB-Ser（16））处磷酸化受磷蛋白（PLB）的蛋白水平。此外，锌的水平，抑制蛋白激酶A的活性，测定在LV组织中的电感耦合等离子体质谱法。与NL犬相比，HF犬的LV匀浆中CaMKII活性和磷酸化PLB-Thr（17）和PLB-Ser（16）水平显著降低，但CaM和Zn水平未降低。这些结果表明，CaMKII活性降低，在失败的LV心肌，这种异常与酶的蛋白表达水平降低，但不是由于钙调素和锌水平的变化。总之，CaMKII活性降低和磷酸化PLB水平可能是HF中肌浆网功能受损的部分原因。
Studies on the status of multifunctional Ca2+-calmodulin (CaM)-dependent protein kinase-II (CaMKII) in failing hearts are limited and controversial. The study was performed in the left ventricular (LV) myocardium of six dogs with heart failure (HF) (LV ejection fraction, 23 +/- 2%) and six normal (NL) dogs. In the LV homogenate, CaMKII activity and its protein level were determined by using the CaMKII peptide and antibody, respectively. Furthermore, the protein level of CaM and phosphorylated phospholamban (PLB) at threonine-17 (PLB-Thr(17)) and serine-16 (PLB-Ser(16)) were also determined in the LV homogenate using a specific antibody. In addition, the level of zinc, which inhibits protein kinase A activity, was determined in the LV tissue by inductively coupled plasma mass spectrometry. CaMKII activity and phosphorylated PLB-Thr(17) and PLB-Ser(16) levels, but not CaM and Zn levels, were significantly reduced in the LV homogenate of dogs with HF compared with NL dogs. These results suggest that CaMKII activity is reduced in the failing LV myocardium, and this abnormality is associated with reduced protein expression level of the enzyme but not due to changes in CaM and zinc levels. In conclusion, reduced CaMKII activity and phosphorylated PLB level may be partly responsible for impaired sarcoplasmic reticulum function in HF.