| Back ground and objectives:Myocardial ischemia and reperfusion injury is myocardial cell of reversible injury in ischemic period transform to inreversible injury after reperfusion.It is a hot spot of medical science study.The mechanism of myocardial ischemia and reperfusion injury is not clear completely,but many studys show that it is a excessive Inflammatory reaction.Vascular endothelial cell and leucocyte stimulated and leucocyte adhered and aggregated and go under endothelial cell by chemokine,these are important]reasons of Inflammatory reaction.Chemokine is a superfamily that consisted of 8～10KDa small molecular mass protein cytokine.Fractalkine(FKN)was a new CX3C chemokine.Fractalkine resides in heart and blood vessel and their endothelial cell.Transmembrane receptor CX3CR1 is special receptor of Fractalkine's target cell such as Natural killer cell, mononuclear cell,macrophage,T lymphocyte,dendritic cell,girter cell present Fractalkine's receptor.Studys show that chemokines such as MCP-1,CINC-1,MIP-2 were attracted quickly to myocardial ischemia and Infarction position after myocardial ischemia and reperfusion.Diverse inhibition of MCP-1,CINC-1,MIP-2 cann't eliminate leukocyte recruitment completely.It's possible that other chemokines participate myocardial ischemia and reperfusion besides MCP-1,CINC-1,MIP-2.Although there isn't report about Fractalkine participating myocardial ischemia and reperfusion,but there was Fractalkine participating ischemia and reperfusion in brain,we believe reasonable that it is possible to participate myocardial ischemia and reperfusion.The reason of rare study of Fractalkine participating myocardial ischemia and reperfusion is that Fractalkine was finded too late.Which cell expresses Fractalkine in myocardial ischemia and reperfusion (Fractalkine is expressed by many kinds and virus)?Which channel does Fractalkine participate myocardial ischemia and reperfusion?Are there any new therapy to effect Fractalkine in myocardial ischemia and reperfusion?These are unknow,they are our investigative focal point.Our study will go from exvivo to in vivo.MethodThe first part of this study Myocardial cell and cardiac fibroblasts in neonatal Sprague -Dawley(SD)rats and the human umbilical vein endothelial cells (HUVECs)were cultured and purified.Establish a model hypoxia-reoxygenated of three cells,To observe cell survival rate by MTT chromatometry and mRNA of FKN of three cells in before ischemia and reperfusion and after reperfusion30min,1hour,2hour,3hour,4hour.The second part of this study Choose human umbilical vein endothelial cells, Experiments were divided into two groups:①hypoxia-reoxygenated group②PDTC (101.tmol/L)group.All were divided into before hypoxia and reperfusion and after reperfusion 30min,1hour,2hour,3hour,4hour seven paragraph.To observe NF-kappaB p65 by flow cytometry,To observe mRNA of FKN in reperfusion 2hour later by different concentration.of PDTC. The third part of this study Establish a model myocardial ischemia and reperfusion of SD rats.Experiments were divided into three groups:①Sham operation group②Ischemia and reperfusion group.③Simvastatin group.All were divided into after reperfusion 1hour,2hour,4hour three paragraph..To observe FKN and CX3CR1 by immunohistochemistryResultThe first part of this study The cultivation of myocardial cell and cardiac fibroblasts in neonatal Sprague -Dawley(SD)rats and the human umbilical vein endothelial cells had succeed.Three cells survival rate in reperfusion were lower than before hypoxia.The cell survival rate of myocardial.cell and HUVECs were lower than cardiac fibroblasts after reperfusion 3 hour.The FKN were expressed in myocardial.cell and HUVECs,FKN was the highest after reperfusion 2hour. HUVECs were higer than myocardial.cell.There was not expressed in cardiac fibroblastsThe second part of this study NF-kB was low before hypoxia in HUVECs, NF-kB was higer after reoxygenated,and was the higest in reoxygenated 1hour.PDTC can restrain FKN.The third part of this study The FKN and CX3CR1 in Ischemia and reperfusion group were higer than sham operation group.They were the higest in after reperfusion 2hour.The same result were showed between Ischemia and reperfusion group and Simvastatin group.ConclusionThe first part of this study①Myocardial cell and cardiac fibroblasts in neonatal SD rats and the human umbilical vein endothelial cells survival rate in reperfusion were lower than before hypoxia.②Chemokine FKN participates myocardial ischemia and reperfusion;Human umbilical vein endothelial cells are the major in FKN express. ③There were not expressed of FKN in cardiac fibroblasts.The second part of this study①NF-kB was higer after reoxygenated,and was the higest in reoxygenated lhour.②PDTC can restrain FKN and CX3CR1,it is confirm Indirect that FKN was regulated by NF-kB.The third part of this study①It is confirm that Chemokine FKN and CX3CR1 participate myocardial ischemia and reperfusion in vivo②Simvastatin can depress FKN and CX3CR1,then lessen myocardial ischemia and reperfusion injury.It prognosticates that FKN and CX3CR1 maybe a major target of lessening myocardial ischemia and reperfusion injury. |
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