Study On The Protective Effect Of PPolyHb On Myocardial Ischemia Reperfusion Injury

Coronary heart disease is a type of heart disease caused by coronary artery occlusion and insufficient blood oxygen supply,which can lead to acute myocardial ischemia and even myocardial infarction.Since the blocked arteries can not be opened promptly after ischemia,the optimal time to restore the blood oxygen supply is missed.Therefore,restoring myocardial perfusion as soon as possible is the fundamental method for the treatment of heart disease.At present,clinical use of drug thrombolysis,coronary artery bypass grafting(CABG),percutaneous coronary intervention(PCI)for treatment,but it can easily cause myocardial ischemia and reperfusion(I/R)damage,The occurrence of I/R leads to the accelerated apoptosis of myocardial cells,the increase of inflammatory cytokines and the release of oxygen free radicals.Therefore,it is urgent to find a new research direction for the treatment of oxygen-supplying drugs in a short period of time.In this study,the polymerized pig hemoglobin(pPolyHb)was synthesized by glutaraldehyde crosslinking agent.It has the ability to carry oxygen,and it can maintain the stable oxygen content effectively in the tissue.In the process of I/R,it is effective to realize rapid oxygenation and to exert myocardial protection.Recent studies have shown that PI3K-Akt signaling pathway plays a protective role in myocardial ischemia-reperfusion injury.In order to explore whether pPolyHb plays a protective role through PI3K-Akt signaling pathway and the effect of PI3K-Akt signaling pathway on mitochondrial autophagy in the process of myocardial ischemia reperfusion injury,we will further explore the protective mechanism of pPolyHb in myocardial ischemia-reperfusion injury.Effects of pPolyHb on apoptosis in ischemia-reperfusion injury: We established the hypoxia-reoxygenation model to simulate ischemia-reperfusion injury.We observed the cell morphology,detected the activity of myocardial cells,and tested the LDH and CK activity level experiments in the supernatant of the cells.The results showed that pPolyHb at the concentration of 20μM can effectively restore normal cells,increase cell viability,and reduce cytotoxicity.Apoptosis and expression of p-Akt protein were detected after PI3K-Akt signaling pathway inhibitor pretreatment.The results show that reoxygenation of pPolyHbcan reduce the rate of apoptosis,reduce the expression of pro-apoptotic proteins,and increase the expression of p-Akt protein.This further demonstrates that pPolyHb inhibits cardiomyocyte apoptosis is regulated by PI3K-Akt signaling pathway;By examining the levels of TNF-ɑ,IL-1β,TGF-β and NF-κBp65,we investigated the anti-inflammatory effects and protective mechanisms of pPolyHb through PI3K-Akt signaling pathway.pPolyHb is a protective effect by regulating the NF-κB signaling pathway through the PI3K-Akt signaling pathway.Protection by mitochondrial autophagy: The levels of Pink1 and Parkin were detected in each group,which were the signal proteins of autophagy in mitochondria.When mitochondrial autophagy was inhibited,apoptosis was detected.The results showed that pPolyHb induced mitochondrial autophagy and inhibited cell apoptosis.After treatment with PI3K-Akt signaling pathway inhibitor,autophagic protein expression was detected.The results showed that the protein expression levels of Pink1 and Parkin decreased significantly,and the PI3K-Akt signaling pathway could affect pPolyHb-induced mitochondrial autophagy.By detecting the expression levels of p-Akt protein in different experimental groups,it was demonstrated that the occurrence of mitochondrial autophagy promoted the expression of p-Akt protein,and further demonstrated that the PI3K-Akt signaling pathway can be protected by pPolyHb-induced mitochondrial autophagy pathway.