BackgroundThe incidence rate and mortality rate of cardiovascular diseases have ranked first in the world for decades.In China,the incidence of cardiovascular disease is increasing year by year.Acute myocardial infarction is one of the most dangerous types of cardiovascular diseases.Timely reperfusion therapy to restore blood flow is the most effective strategy to treat myocardial infarction.However,reperfusion can also cause reperfusion injury defined as ischemia/reperfusion(I/R)injury and affect the prognosis of patients.At present,the clinical prevention and treatment of myocardial I/R injury is still in the exploratory stage,and the effect is unstable.There is still a lack of effective methods,which suggests more mechanism investigations are needed.Ferroptosis is identified as a new type of programmed cell death found in recent years.Its occurrence is mainly related to iron overload and lipid peroxidation.It has different morphological characteristics from other programmed death.Ferroptosis is involved in the occurrence and development of various cardiovascular diseases.Studies have shown that inhibiting ferroptosis of cardiomyocytes significantly reduces reperfusion injury and cardiac dysfunction.However,there is still a lack of research on the longitudinal molecular mechanism of ferroptosis.Our high throughput sequencing analysis revealed that activating transcription factor 3(ATF3)might plays an important role in cardiomyocyte cell death.ATF3 has been reported to be involved in many cardiovascular diseases.However,its role remains controversial.The role of ATF3 in ferroptosis in myocardial I/R injury is still unclear.Objectives1.Based on the mouse I/R model and neonatal mouse cells(NMCs)hypoxia/reoxygenation(H/R)model,RNA sequencing(RNA-seq),western blot and qpcr were used to analyze the expression of ATF3.2.To illustrate the effects of ATF3 on myocardial I/R injury.3.To investigate the role of ATF3 on cardiac ferroptosis regulation in myocardial I/R injury.MethodsRNA sequencing(RNA-seq)was used to analyze the differentially expressed genes in mouse myocardium at different reperfusion times,and ATF3 was selected for the next study.The effects of ATF3 on cardiac ferroptosis in I/R injury were analyzed.Using gene knockout,recovery,overexpression and other technologies,combined with molecular biological means such as RNA-seq and chromatin immunoprecipitation(ChIP),we found that FANCD2 may be the gene directly regulated downstream of ATF3,and further illustrated the effects of ATF3 on I/R induced ferroptosis.Results1.ATF3 is upregulated in myocardial I/R injury and the translocation to nuclei was increased;2.Knockout ATF3 amplified the I/R injury,and reexpression of ATF3 reduced the I/Rinjury;3.ATF3 could directly bind to the transcription initiation site of ferroptosis inhibited gene FANCD2 and promote its transcription;4.ATF3 reduces ferroptosis induced by myocardial I/R or H/R injury;5.ATF3 inhibits ferroptosis induced by erastin and RSL3 and improves the cell viability;6.ATF3 exerts therapeutic effect on wildtype mouse myocardial I/R injury.ConclusionsWe have elucidated that inhibits the ferroptotic death of cardiomyocytes in response to myocardial I/R injury,which might be related with the regulation of FANCD2 by binding with transcription site of FANCD2 and promoting FANCD2 transcription. |