Elevated isatin ameliorates heart injury in patients with myocardial infarction after rehabilitation treatment-based metabolomics screening.

BACKGROUND

Rehabilitation exercise after acute myocardial infarction is helpful for cardiac function recovery. Isatin, an endogenous indole derivative of tryptophan metabolism, exhibits anti-inflammatory and antioxidant properties, but its role in myocardial injury repair post-myocardial infarction (MI) remains unclear.

PURPOSE: This study aimed to investigate isatin's cardioprotective effects and molecular mechanisms in post-rehabilitation AMI patients through multi-omics approaches.

STUDY

DESIGN

This study aimed to systematically investigate the protective effects and molecular mechanisms of isatin on cardiac injury in patients with AMI following rehabilitation, using untargeted metabolomics, HuProt™ microarray, network pharmacology (NP), surface plasmon resonance (SPR), molecular docking, molecular dynamics (MD), animal models, and cell experiments.

METHODS

Serum isatin levels were measured in STEMI patients' pre-/post-Enhanced external counterpulsation (EECP) rehabilitation using untargeted metabolomics. HuProtTM microarray and NP was used to identify the downstream targets of isatin, validated through SPR, molecular docking, and dynamics. A murine AMI model was applied to assess the protective function of isatin. H2O2-treated cardiomyocytes and LPS-treated macrophages were used to explore the potential protective mechanisms of isatin.

RESULTS

EECP elevated serum isatin in STEMI patients, correlating with better cardiopulmonary function. S100A8 was identified as the primary target by HuProt™ microarray and NP. Isatin formed a 2.1 Å hydrogen bond with S100A8-GLU41. SPR KD=57.9 μM; Docking score=-5.37 kcal/mol; MD ΔG=-15.35 ± 1.95 kcal/mol. Isatin improved cardiac function in AMI mice. Isatin enhanced HL-1 cardiomyocyte viability while reducing apoptosis, and decreased macrophage IL-1β, IL-6, IL-1α, and TNF-α secretion.

CONCLUSION

This study demonstrates that EECP enhances cardiac rehabilitation in STEMI patients by upregulating endogenous isatin, which exerts cardioprotective effects through direct targeting of S100A8, leading to improved cardiac function and reduced oxidative stress and inflammation, with the molecular mechanism confirmed by integrated multi-omics analyses.