The Effect Of AMPK-p53-klf2a Pathway In Hyperglycemia-induced Cardiac Remodeling In Adult Zebrafish

Background: Diabetic cardiomyopathy(DCM)concerned a host of people as the incidence of diabetes mellitus increased year by year.DCM is defined as a type of cardiomyopathy in diabetes patients that is disassociated with coronary heart disease,hypertensive heart disease,valvular heart disease and other heart disease.Studies have shown that DCM may be connected with myocardial cell apoptosis,oxidative stress and mitochondrial dysfunction,still the molecular biological mechanism remains a further exploration.Zebrafish,known as Danio rerio,which is a emerging animal model,has highly homologous to humansv in hereditary.The study was to establish a high glucose model to observe high glucose effect to the heart of zebrafish and step forward to investigate the mechanism involved,which serve as a foundation for a better preparation to establish DCM model platform and to screen drug target.The model still not reports worldwide.Methods and Results: We simulate type 1 diabetes mellitus via intraperitoneal injection into zebrafish with streptozocin to establish DCM model and TUNEL fluorescence staining indicates that cardiomyocyte apoptosis significantly increased.Transmission electron microscopy(TEM)and(H & E)staining showed that the myocardium disorder,myocardial fiber loss,phagocytic bubble formation as well as mitochondrial condensation exist in this model.Electrocardiographic analysis revealed that reduced heart rate,increased incidences of ST-T change and voltage alternation in the hyperglycemic fish.Echocardiographic studies demonstrated diastolic and systolic dysfunction in the heart,ejection fraction((EF)and cardiac output(CO)decreased.Enlarged heart can be observed in the hyperglycemic fish.Real-time PCR and Western-blot indicated the AMPK was inhibited while the expression of p53 increased and Klf2 a decreased in the myocardium of the zebrafish.Activated AMPK triggered by A769662 lead to a reduction of expression in p53 downstream and Klf2 a up-regulation,the cardiomyocyte apoptosis was significantly reduced in myocardium.Echocardiographic studies demonstrated cardiac function improvement.What's more,Real-time PCR indicated hyperglycemic primary cardiomyocytes the p53 increased and Klf2 a decreased while A769662 intervene lead to a reduction expression of p53 and increased Klf2 a,and the cardiomyocyte apoptosis was significantly reduced in hyperglycemic primary cardiomyocytes.Real-time PCR analysis vitro reconstruction of lentivirus knockout system indicated knockout AMPK up-regulation expression of p53 and reduce the expression of Klf2 a,inhibit the expression of p53 expression can increase the expression of Klf2 a while AMPK expression had no obvious effect,silent klf2 a don't influence the expression of AMPK and klf2 a.Suggest AMPK-p53-klf2 a signaling pathways involved in hyperglycemic induced myocardial remodeling.Conclusions: We have successfully established a model of hyperglycemia cardiomyopathy in adult zebrafish whose remodeling phenotype is similar to humans.Myocardial apoptosis plays a cardinal role in myocardial remodeling,AMPK-p53-klf2 a signaling pathway is involved in the pathophysiological process and may be a potential targets intervening diabetic cardiomyopathy.