PPENK-MIDGE-NLS Transfect Leucocyte To Prevent Myocardial Ischemia-reperfusion Injury And The Mechanism Behind It

Objective: Myocardial ischemia-reperfusion injury is a clinical dilemma, a large number of experiments have shown that myocardial ischemic preconditioning/postconditioning are potent endogenous protective mechanisms against ischemia-reperfusion injury, at the same time enkephalin can mimics preconditioning/postconditioning induce significant myocardial protective effects. Because the clinical application of opioids have many limitations at ischemic circumstances, gene therapy is a promising research direction to increase the endogenous enkephalin. PPENK-MIDGE-NLS gene vector overcomes the drawback of viral vector and plasmid vector. It can transfect leukocyte, induces leukocyte continues produce and targeted release endogenous enkephalin in myocardial injury area, so as to protect myocardium, and at to prove an innovative method for preventing and treating of myocardial ischemia-reperfusion injury.Methods: This study construct PPENK-MIDGE-NLS gene vector of enkephalin by minimalistic immunologically defined gene expression and then intravenously inject PPENK-MIDGE-NLS to transfect leukocyte. Combining the advantages of leukocyte aggregation and infiltration to the myocardial injury site, PPENK-MIDGE-NLS inducesleukocyte continues produce and targeted release endogenous enkephalin in myocardial injury area. Transfection efficiency will be confirmed by flow cytometry. The effect of PPENK-MIDGE-NLS on gene expression and content of enkephalin precursor protection proenkephalin, ENK and metabolites are detected by Western Blot, immunohistochemistry and radioimmunity at myocardial tissue. The feasibility and efficacy of PPENK-MIDGE-NLS gene vector inducing leukocyte to increase content of endougenous enkephalin for myocardial protection are also evaluated by the changes of haemodynamics, infarction area and CK-MB.Results: 1. This study has used biochemical method to construct PPENK-MIDGE-NLS gene vector successfully. 2. Local injection of PPENK-MIDGE-NLS gene vector can transfect living cells and increase the quantity of PENK protein, and intravenous injection of PPENK-MIDGE-NLS can transfect leukocyte and infiltrate to the myocardial injury site. 3. When rats suffer from myocardial ischemia-reperfusion injury, PPENKMIDGE-NLS gene vector has improved hemodynamic parameters, reduce the myocardial infarction area, CK-MB activity, and AI(P < 0.01).Conclusion: PPENK-MIDGE-NLS gene vector can transfect rat leukocyte and protect myocardium.