Qingxin Jieyu Granule alleviates myocardial infarction through inhibiting neutrophil extracellular traps via activating ANXA1/FPR2 axis

Background

Myocardial infarction (MI), representing the most severe manifestation of coronary artery disease (CAD), stands as a primary concern in the prevention and management of cardiovascular diseases. Clinical evidence demonstrates that Qingxin Jieyu Granule (QXJYG) is efficacious in treatment of MI patients. However, the mechanisms underlying its therapeutic effects remain to be elucidated.

Purpose

This study aimed to evaluate the effects of QXJYG on MI and investigate its underlying mechanisms.

Materials and methods

The MI model in rats was developed through ligating the left anterior descending (LAD) artery. The effect of QXJYG on cardiac function impairment in MI rats was assessed by echocardiography, while the improvement of cardiomyocyte morphology and myocardial fibrosis after treatment with QXJYG was evaluated through hematoxylin-eosin (H&E) staining and Masson staining. The chemical constituents of QXJYG in blood were identified by using the UPLC-Q-TOF/MS technique. Furthermore, the molecular mechanism underlying the QXJYG therapeutic effect in MI was postulated based on the disease gene-drug target network analysis. Other technical methods such as ELISA, immunohistochemical staining, Western Blot analysis and application of pharmacological inhibitors were employed to verify the effectiveness of QXJYG in treating MI and explore its potential molecular targets.

Results

The cardiac function in experimental rats post-MI was significantly impaired, as evidenced by an enlarged infarction area, disordered arrangement of cardiomyocytes, and aggravated myocardial fibrosis. QXJYG treatment significantly enhanced the cardiac function and reduced the pathological damage of the cardiac tissue in MI rats. Through the network pharmacology analysis, we identified that FPR2 might be a potential target of QXJYG in its cardiac protection role. QXJYG markedly downregulated the level of neutrophil extracellular traps (NETs) in MI rats, specifically manifested as a significant reduction in the Histone-DNA level and expression of myeloperoxidase (MPO) and citrullinated histone H3 (CitH3) proteins. Furthermore, QXJYG upregulated the levels of ANXA1 and FPR2 proteins in MI rats. The level of FPR2 was markedly reduced in MI rats upon administration of WRW4, a specific inhibitor of FPR2, which was associated with exacerbated MI injury and an elevated level of NETs. When WRW4 was co-administered with QXJYG, the cardioprotective effects of QXJYG on MI were significantly diminished. However, the addition of DNase I did not result in significant changes of the outcomes in MI rats after QXJYG intervention.

Conclusion

QXJYG treatment alleviates cardiac tissue injury in MI rats by inhibiting NETs through activating the ANXA1/FPR2 axis. The findings extend our understanding of the therapeutic effectiveness of QXJYG and offer a scientific foundation for the clinical utilization of QXJYG.