Zhang Yong-jun, Wang Jia-ning, Tang Jun-ming, Huang Yong-zhang, Yang Jian-ye, Guo Ling-yun
Institute of Clinical Medicine, People's Hospital Affiliated to Yunyang Medical College, Shiyan 442000, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2009 Dec;29(12):2429-32.
To investigate the transduction efficiency of purified PEP-1-CAT fusion protein into rat heart and the protective effect of the fusion protein against myocardial ischemia-reperfusion injury.
PEP-1-CAT or CAT (500 microg) was injected in SD rats via the caudal vein, using normal saline as the control, and the hearts were harvested at 0.5, 1, 2, 4, 8, and 24 h after the injection. The transduction efficiency was evaluated by immunofluorescence technique, and the CAT activity was measured. Forty rats were randomized into 5 groups, namely the sham-operated group, ischemia-reperfusion group, and 3 PEP-1-CAT -treated groups (100, 300, and 500 microg). The left main coronary artery was occluded for 1 h followed by a 2-h reperfusion, and at the end of reperfusion, serum LDH and CK and MDA content in the myocardium were measured.
No green fluorescence was observed in saline group or CAT group. Bright green fluorescence was observed in PEP-1-CAT groups at different time points, most conspicuous at 8 h. No significant difference in CAT activity was found between CAT group and saline group (P>0.05); with the lapse of time, CAT activity in PEP-1-CAT group increased gradually, reaching the peak level at 8 h, which was 4.2 folds of that in the saline group. LDH ,CK and MDA were significantly lower in PEP-1-CAT- groups than in ischemia-reperfusion group (P<0.01).
PEP-1 can mediate the transduction of CAT in rat heart in a time-dependent manner, and PEP-1-CAT preconditioning provides a protective effect against ischemia- reperfusion injury in rats.
研究纯化的PEP-1-CAT融合蛋白导入大鼠心脏的转导效率及其对心肌缺血再灌注损伤的保护作用。
将PEP-1-CAT或CAT（500微克）经尾静脉注入SD大鼠，以生理盐水作为对照，在注射后0.5、1、2、4、8和24小时采集心脏。通过免疫荧光技术评估转导效率，并测定CAT活性。40只大鼠随机分为5组，即假手术组、缺血再灌注组和3个PEP-1-CAT治疗组（100、300和500微克）。左冠状动脉结扎1小时后再灌注2小时，在再灌注结束时，测定血清乳酸脱氢酶（LDH）、肌酸激酶（CK）以及心肌中丙二醛（MDA）含量。
生理盐水组和CAT组未观察到绿色荧光。PEP-1-CAT组在不同时间点观察到明亮的绿色荧光，8小时时最为明显。CAT组和生理盐水组之间的CAT活性无显著差异（P>0.0５）；随着时间的推移，PEP-1-CAT组的CAT活性逐渐增加，在8小时达到峰值水平，是生理盐水组的4.2倍。PEP-1-CAT组的LDH、CK和MDA显著低于缺血再灌注组（P<0.01）。
PEP-1可介导CAT在大鼠心脏中的转导，且呈时间依赖性，PEP-1-CAT预处理对大鼠缺血再灌注损伤具有保护作用。
