Tsuji Tsuyoshi, Del Monte Federica, Yoshikawa Yoshiro, Abe Takehisa, Shimizu Juichiro, Nakajima-Takenaka Chikako, Taniguchi Shigeki, Hajjar Roger J, Takaki Miyako
Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
Am J Physiol Heart Circ Physiol. 2009 Feb;296(2):H310-7. doi: 10.1152/ajpheart.00975.2008. Epub 2008 Dec 12.
In failing hearts, a deficiency in sarco(endo)plasmic reticulum Ca2+ -ATPase (SERCA)2a results in abnormal Ca2+ handling and diminished contraction. In addition, a decrease in the phosphorylation of phospholamban (PLB) has been reported. Gene transfer of antisense PLB (asPLB) can improve contractile function in the failing human myocardium. Gene transfer of SERCA2a improves survival and the energy potential in failing hearts. The aim of present study was to evaluate whether enhancement of SERCA2a function prevents acute Ca2+ overload-induced left ventricular (LV) dysfunction in rat hearts. We ablated PLB using adenoviral gene transfer of asPLB by a new and less invasive gene delivery method, which involved a percutaneous technique. Experiments were performed on 13 excised cross-circulated rat hearts: 5 rats underwent sham operations, 4 rats underwent gene transfer of the reporter gene beta-galactosidase (Ad.beta-gal), and 4 rats underwent gene transfer of asPLB (Ad.asPLB). After clearance of high Ca2+ infused into the coronary, there was LV contractile dysfunction associated with the decreased myocardial O2 consumption per beat (Vo2) intercept (equal to decreased Vo2 for Ca2+ handling in excitation-contraction coupling) of the Vo2-systolic pressure-volume area (PVA; total mechanical energy per beat) linear relation in the hearts that underwent sham operation and had been infected with Ad.beta-gal. Hearts that had been infected with Ad.asPLB were rescued from LV contractile dysfunction associated with an unchanged Vo2 intercept of the Vo2-PVA linear relation. We conclude that SERCA2a function enhanced by adenoviral gene transfer of asPLB prevents Ca2+ overload-induced LV contractile dysfunction in terms of mechanical work and especially energetics.
在衰竭心脏中，肌浆（内质）网Ca2+ -ATP酶（SERCA）2a的缺乏会导致Ca2+ 处理异常和收缩力减弱。此外，有报道称受磷蛋白（PLB）的磷酸化水平降低。反义PLB（asPLB）的基因转移可改善衰竭人体心肌的收缩功能。SERCA2a的基因转移可提高衰竭心脏的存活率和能量储备。本研究的目的是评估增强SERCA2a功能是否能预防大鼠心脏急性Ca2+ 超载诱导的左心室（LV）功能障碍。我们采用一种新的、侵入性较小的基因递送方法，即经皮技术，通过腺病毒介导的asPLB基因转移来消除PLB。对13个离体交叉循环大鼠心脏进行了实验：5只大鼠接受假手术，4只大鼠接受报告基因β-半乳糖苷酶（Ad.β-gal）的基因转移，4只大鼠接受asPLB（Ad.asPLB）的基因转移。在清除冠状动脉内注入的高Ca2+ 后，接受假手术并感染Ad.β-gal的心脏出现LV收缩功能障碍，其每搏心肌耗氧量（Vo2）截距降低（相当于兴奋-收缩偶联中Ca2+ 处理的Vo2降低），这是Vo2-收缩压-容积面积（PVA；每搏总机械能）线性关系的表现。感染Ad.asPLB的心脏从与Vo2-PVA线性关系的Vo2截距不变相关的LV收缩功能障碍中得到挽救。我们得出结论，通过腺病毒介导的asPLB基因转移增强的SERCA2a功能，在机械功方面，尤其是在能量学方面，可预防Ca2+ 超载诱导的LV收缩功能障碍。
