Abstract:

Objective To observe the expression of cyp2j3 after intramyocardial injection of plasmid pcDNA3.1-2J3 and examine the effects of cyp2j3 gene transfer on myocardial ischemia-reperfusion injury.
Methods Fifty-four male Wistar rats were randomly divided into three groups as follows: normal saline NS group, pcDNA3.1 group and pcDNA3.1-2J3 group, 80 μL normal saline or 80 μL pcDNA3.1 or 80 μL pcDNA3.1-2J3(1 g/L) was injected into 4 sites of left myocardium respectively. Two weeks after gene transfection, six rats from each group were sacrificed to determine the expressions of CYP2J3 mRNA and CYP2J3 protein in myocardial tissue by RTPCR and Western blotting respectively. The other rats were subjected to 45 min ischemia and 120 min reperfusion. Cardiac function was recorded by the use of BL-420F instruments. Infarction size was measured by triphenyltetrazolium chloride(TTC) staining.
Results Compared with the control group, CYP2J3 mRNA and CYP2J3 protein were overexpressed in pcDNA3.1-2J3 group after two weeks gene transfer via direct injection. Left ventricular end-systolic pressure(LVESP) and left ventricular maximal velocities of contraction and relaxation(±LV dp/dtmax) were significantly increased in pcDNA3.1-2J3 group after 45 min ischemia and 120 min reperfusion. Myocardial infarction size also reduce in gene transfer pcDNA3.1-2J3 group compared with pcDNA3.1 group in I/R model(P<0.05).
Conclusion Cyp2j3 can be effectively transferred into the myocardial tissue and express via direct injection pcDNA3.1-2J3 in vivo. Intramyocardial injection of plasmid pcDNA3.1-2J3 can attenuate the myocardial injury induced by ischemia or reperfusion.

Key words: cytochrome P450, gene transfection, ischemia/reperfusion injury, epoxyeicosatrienoic acids