腺病毒介导的心肌蛋白激酶Cε基因转移的心肌保护作用

Cardioprotective Effect by Adenovirus-mediated Protein Kinase C-ε Gene Transfer to Myocardium of Mouse

目的 蛋白激酶Cε (ProteinKinaseCε,PKCε)转基因小鼠表现了保护心肌缺血 /再灌注损伤的遗传特性 (心肌保护表型 )。本文旨在研究腺病毒介导的成年小鼠心肌直接的PKCε基因转移对心肌缺血 -再灌注损伤的影响。方法 通过克隆PKCεcDNA到人类 5型腺病毒基因组DNA的E1区建立表达PKCε基因的重组腺病毒。直接注射重组腺病毒 3 3× 10 10 菌落形成单位 (pfu) /体重 (kg)到小鼠 (10～ 13周 ) ,对照鼠被直接注射相同剂量的空载腺病毒。Western免疫印迹被用于测定PKCε蛋白质表达水平。通过冠状动脉阻断 /再灌注、染色、照像和微机计算进行心肌梗死分析。结果 PKCε重组腺病毒直接心肌注射优于静脉注射 ;直接心肌注射后 4 8h ,基因转移鼠心肌PKCε蛋白质表达水平比对照鼠增加近 4倍。心脏重、左室重、危险区重和危险区重 /左室重百分数在PKCε基因转移和对照小鼠之间无显著差异 ,而PKCε基因转移小鼠的梗死重 [(35 4± 3 1)mgvs(10 3±1 3)mg]、梗死 /危险区域百分数 (5 1 1%± 0 3%vs 17 0 %± 2 6 % )、梗死 /左室百分数 (30 0 %±3 0 %vs 9 2 %± 0 5 % )明显低于对照鼠 (均P <0 0 1)。结论 腺病毒介导的、心肌直接的PKCε基因转移小鼠表现了对心肌梗死的保护作用。

Objective Protein kinase C-epsilon (PKC ε) transgenic mice exhibit inherent cardioprotection against myocardial ischemia-reperfusion injury. The present study aims to investigate the role of the adenovirus-mediated PKC ε gene transfer to myocardium of adult mouse on myocardial ischemia-reperfusion insult. Methods Recombinant adenovirus expressing rabbit PKC ε gene was generated by cloning PKC ε cDNA into E1 region of human adenoviral type 5 genomic DNA. 3.3×10{10} plaque forming units (pfu)/kg body weight of the PKC ε adenovirus were directly injected to myocardium of mice. Control mice were directly injected same dose of empty vector adenoviruses. PKC ε protein levels were determined by Western immunoblotting. Left ventricular infarction was established by 30 min of coronary occlusion followed by 24 hours of reperfusion. Infarct size analyses were performed by staining with 2, 3, 5-triphenyltetrazolium chloride and phthalo blue dye, photographing and calculating. Results PKC ε gene transfer mice were associated with a approximate 4-fold of increase in PKC ε transgene protein levels at 48 hours after direct myocardial injection when compared to control mice. There were no significant differences in heart weight, LV weight, risk area weight and percentage of risk area weight to LV weight between PKC ε gene transfer mice and control mice. However, infarct weight (35.4±3.1)mg vs (10.3±1.3) mg, percentage of infarct to risk area (51.1±0.3 vs 17.0±2.6) and percentage of infarct to LV (30.0±3.0 vs 9.2±0.5) in PKC ε gene transfer mice were reduced significantly when compared with control mice. Conclusion Adenovirus-mediated, myocardium-directed PKC ε gene transfer enhanced resistance against myocardial ischemia- reperfusion insult.