Aim of the study
Inflammation plays a critical role in acute myocardial infarction (AMI). This study aims to explore the treatment effects of ESA in AMI, as well as the underlying mechanism.
Conclusion
Our study was the first to demonstrate a cardiac protective role of ESA in AMI. Mechanism study indicated that the treatment effects of ESA are mainly attributed to its anti-inflammatory activity that was mediated by the HMGB1/TLR4/NF-κB pathway.
Methods
An AMI mouse model was established in mice via left anterior descending coronary artery (LAD) ligation. After surgery, ESA was injected at doses of 0.5, 1.25, and 2.5 mg/kg, respectively. Myocardial infarction size, cardiomyocyte apoptosis and cardiac echocardiography were studied. The potential mechanism of action of ESA was investigated by RNA-seq, Western blot, surface plasmon resonance (SPR), molecular docking, and immunofluorescence staining.
Results
ESA treatment not only significantly reduced myocardial infarct size, decreased myocardial cell apoptosis, and inhibited inflammatory cell infiltration, but also facilitated to improve cardiac function. RNA-seq and Western blot analysis proved that ESA treatment-induced differential expression genes mainly enriched in HMGB1/TLR4/NF-κB pathway. Consistently, ESA treatment resulted into the down-regulation of IL-1β, IL-6, and TNF-α levels after AMI. Furthermore, SPR and molecular docking results showed that ESA could bind directly to HMGB1, thereby impeding the activation of the downstream TLR4/NF-κB pathway. The immunofluorescence staining and Western blot results at the cellular level also demonstrated that ESA inhibited the activation of the HMGB1/TLR4/NF-κB pathway in H9C2 cells.