Possible Role Of Galectin-1 In Rat Model Of Myocardial Hypoxia Injury And Its Related Mechanism

Part?: Establishment of the hypoxia injury model in rat cardiomyocytes Objective:To explore and establish a stable rat model of myocardial hypoxia injury Methods :First,we cultured myocardial cells of H9C2 rats,with different concentrations of sodium dithionite,divided into two groups—hypoxia for 2 hours and hypoxia for 4 hours,then discarded medium containing sodium dithionite,replaced with normal medium reoxygenation incubated for 1 hour.The viability of cells,the release of lactate dehydrogenase,the degree of lipid oxidation and the concentration of reactive oxygen species were tested separately,which evaluated the effect of ischemia and hypoxia model.Results:With the increase of the concentration of the drug,the viable cells were less and less,and the refractive index was reduced,and the shape changed from long spindle shape to elliptic under the microscope by using sodium dithionite solution for hypoxia/reoxygenation treatment.In the two groups,when the concentration of sodium dithionite was more than 3mM,the survival rate of the cardiomyocytes decreased significantly.However,in the same condition,the release of LDH,the lipid oxidation and the active oxygen content all increased.Conclusion:Using sodium dithionite can establish a stable rat model of myocardial injury.Sodium dithionite doesn't damage rat cardiomyocytes.When the concentration of sodium dithionite reaches 3mM,the cell viability decrease,but the concentration of active oxygen,LDH and lipid oxidation obviously increase compared with the control group and low concentration drug group.Part?: Effect of Galectin-1 on Cardiomyocytes in Hypoxia Injury ModelObjective:To investigate the effect of Galectin-1 protein on cardiomyocytes influenced by hypoxia in rats and its related mechanism.Methods: First,H9C2 cells were stimulated with hypoxia/reoxygenation by different concentrations of recombinant rat Galectin-1 protein,and their effects on cell viability and cell apoptosis were observed.Second,lentivirus vector was transfected into H9C2 cells,which established hypoxia injury model to express Galectin-1 protein.We detected Galectin-1 expression and cell survival and apoptosis rate in the model,and finally explored Galectin-1 playing a corresponding role in the expression of signal pathway protein.Results:The proliferation of H9C2 cells was increased and the apoptosis was decreased after the addition of recombinant Galectin-1 protein once cell injured.Compared with the normal group,the expression of Galectin-1 decreased after hypoxia,Galectin-1 was significantly increased in H9C2 cells transfected with Galectin-1 lentivirus vector,and the apoptotic rate of H9C2 cells was decreased.The levels of AKT,P38 and ERK decreased,while the phosphorylation of Galectin-1 protein was significantly increased after overexpression of Galectin-1 protein compared with normal group.Conclusion : Exogenous Galectin-1 protein has a protective effect on cardiomyocytes by hypoxia-reperfusion injury.Overexpression of Galectin-1 protein in cardiomyocytes can reduce cell damage after hypoxia.Galectin-1 protein may play a role in protecting cardiomyocytes after hypoxia injury through AKT,P38 and ERK signaling pathways.