Effect And Mechanism Of PDGF-regulated Autophagy On Injured Rat Cardiomyocytes

Objective:Heart failure is the end-stage manifestation of different types of heart diseases,and it is an unconquered "fortress" in the cardiovascular field.Our country has a large population and a high incidence of cardiovascular diseases.Although the treatment of heart failure has made great progress compared with the previous years,the number of people suffering from heart failure is still increasing.Despite the continuous advancement of medical treatment,the mortality rate and readmission rate of the disease remain high.Non-pharmaceutical device treatment is developing rapidly,but the current main treatment strategy for heart failure is still drug therapy.However,the research and development of related drugs has not made significant progress in the past 20 years.Heart failure is mainly caused by ventricular remodeling caused by myocardial cell damage.Therefore,the research and development of drugs to protect myocardial cells and improve myocardial cell damage has always been the focus of everyone’s attention.PDGF is a member of the growth factor family and is a promoter of mitosis.It plays an important role in cell proliferation,migration,apoptosis,and angiogenesis.Studies have shown that PDGF plays an important role in the process of cardiomyocyte proliferation and heart regeneration in newborn mice after zebrafish myocardial injury.In recent years,more and more studies have shown that autophagy is closely related to the occurrence and development of heart failure.Autophagy also plays an important role in the process of heart regeneration.Decreasing cardiomyocyte autophagy can inhibit cardiomyocyte apoptosis;autophagy is a Highly evolutionary conserved life process,maintaining cell homeostasis in the basic state,over-activation or insufficient autophagy may lead to a variety of cell pathological changes.Autophagy is regulated by multiple signal pathways,among which AMPK and Notch1 are important signal pathways related to autophagy.AMPK pathway can regulate autophagy to inhibit cardiomyocyte apoptosis and promote their survival.Scholars have found that the Notch1 signaling pathway can regulate autophagy to act on renal tubular epithelial cells and affect the progression of kidney disease.Others have pointed out that it plays an important role in heart regeneration.This topic aims to observe the effects of PDGF on the physiological functions of rat cardiomyocytes,and explore the possible regulatory mechanism of autophagy,and to explore whether PDGF can regulate autophagy-related signal pathways AMPK and Notch1 to inhibit cardiomyocyte apoptosis and promote cardiomyocytes The internal mechanism of survival provides a theoretical basis for the future development of PDGF as a new anti-heart failure drug.Methods:Rat cardiomyocytes(H9C2)were selected as the research object,and H9C2 was injuried with LPS to construct a cardiomyocyte injury model.After treatment with LPS at concentrations of 0(NC group),1,2.5,5,and 10ug/ml,Cell viability and apoptosis level were tested.The injury models were treated with PDGF at concentrations of 0(NC group),5,10,20,50 ng/ml,and cell viability and apoptosis levels were detected again.PDGF,autophagy inhibitor CQ,AMPK signaling pathway inhibitor Compound C,and Notch1 signaling pathway inhibitor DAPT were used to treat cardiomyocyte injury models to detect cell viability,apoptosis.and autophagy levels in each group,and RT-PCR to detect autophagy Related signal pathway mRNA expression,Western blotting was used to detect autophagy signal pathway protein expression level.Results:1.LPS inhibited H9C2 cell viability in a concentration-dependent manner and promoted H9C2 cell apoptosis.In the time and concentration gradient designed in this experiment,at the 24h time point,5ug/ml LPS had a significant effect on H9C2 cells;2.PDGF enhances the viability of H9C2 cells after LPS injury in a concentration-dependent manner and inhibits their apoptosis.At the 24h time point,PDGF at 20ng/ml has a significant protective effect on the injury modelS;3.PDGF,inhibiting the level of autophagy,inhibiting the AMPK signal pathway,and inhibiting the Notch1 signal pathway can all rescue the decline in H9C2 cell viability and apoptosis caused by LPS;4.CQ can inhibit the level of autophagy,and Compound C can regulate the inhibition of AMPK signal pathway Autophagy level;5.LPS enhances the autophagy level of H9C2 cells and can activate the AMPK signaling pathway;PDGF inhibits the autophagy level of H9C2 cells after LPS injury,and inhibits the AMPK signaling pathway,while LPS and PDGF have no significant effect on the Notch1 signaling pathway effect.Conclusion:1.PDGF can inhibit the decrease of cell survival rate and cell apoptosis after lipopolysaccharide damage H9C2;2.Lipopolysaccharides increase the autophagy level of H9C2 cells and cause damage to the cells,reduce their cell survival rate,and induce apoptosis;3.PDGF reduces the level of autophagy by inhibiting AMPK signaling pathway;4.Inhibiting autophagy and inhibiting AMPK signaling pathway can protect H9C2 cells after lipopolysaccharide injury;5.PDGF inhibition of autophagy has no obvious relationship with Notch1 signaling pathway.