Tetramethylpyrazine alleviates ventricular remodeling after myocardial infarction by regulating Sirt1/p300/Yy1/sST2...

Adverse ventricular remodeling following myocardial infarction (MI) is a critical factor in the progression of heart failure (HF). However, clinical interventions are limited by the lack of reliable biomarkers and targeted therapies. Soluble suppression of tumorigenicity 2 (sST2) is recognized as a prognostic biomarker in HF, with elevated levels associated with poorer outcomes, while its reduction is indicative of successful therapeutic intervention in mitigating remodeling. Tetramethylpyrazine (TMPZ), a bioactive alkaloid derived from Ligusticum chuanxiong Hort., has demonstrated potential in the treatment of MI, with our previous research linking it to the suppression of sST2. Nevertheless, the mechanisms by which TMPZ regulates sST2-mediated remodeling remain inadequately understood.

This study aims to elucidate the molecular mechanisms through which TMPZ modulates sST2 to alleviate ventricular remodeling post-MI.

MI was induced in mice, followed by TMPZ treatment for 1, 3, 7, and 14 days​​. Cardiac function was monitored via echocardiography pre-surgery and on days 3, 7, and 14 post-MI. Serum myocardial enzymes were quantified automatically. Cardiac tissue fibrosis and histopathology were evaluated using Masson's trichrome and HE staining, while immunohistochemistry detected ventricular remodeling-associated proteins. sST2 secretion was measured by ELISA. Bioinformatic analyses (KEGG and GO) were performed on the overlapping targets between the cardiac transcriptomic dataset at 3 days post-MI (GSE217268) and Ligusticum chuanxiong Hort.. Primary cardiomyocytes were subjected to oxygen-glucose deprivation (OGD) and treated with TMPZ. Measurement of cell viability using the CCK-8 assay. qRT-PCR and Western blotting evaluated mRNA and protein expression of Sirt1, p300, Yy1, and sST2. Molecular docking and SPR analysis characterized TMPZ-Sirt1 binding. Sirt1 activity in cardiac tissue was measured colorimetrically. Co-immunoprecipitation (Co-IP) assessed p300 acetylation and Yy1 interaction. The Sirt1 inhibitor EX527 confirmed TMPZ-mediated sST2 regulation via Sirt1 in the MI model.

TMPZ administration markedly improved cardiac function, reduced circulating biomarkers of myocardial injury, attenuated histopathological damage, and inhibited ventricular remodeling in a murine model of MI. Treatment with TMPZ also significantly lowered serum levels of sST2. Integrative bioinformatic analysis of GEO datasets and network pharmacology suggested that Ligusticum chuanxiong Hort. influences biological processes related to protein deacetylation, specifically via the differentially expressed gene Sirt1. Subsequent in vivo and in vitro experiments established that TMPZ mediates the downregulation of sST2 through the Sirt1/p300/Yy1/sST2 signaling cascade. Molecular docking and SPR analysis suggested a potential interaction between TMPZ and Sirt1. Based on this interaction, we further verified that TMPZ enhances Sirt1's deacetylase activity. Co-IP experiments showed that TMPZ treatment reduces acetylation of the transcriptional coactivator p300, which is a downstream effector of Sirt1, resulting in inhibition of Yy1 activation and consequent suppression of sST2 synthesis and secretion. Finally, in vivo inhibition of Sirt1 with EX527 confirmed that the cardioprotective effects of TMPZ against post-MI ventricular remodeling are dependent on Sirt1-mediated reduction of sST2 secretion.

We found that increased serum sST2 levels were significantly correlated with the progression of adverse ventricular remodeling following MI. Furthermore, our study provides the first preclinical evidence demonstrating that TMPZ attenuates this remodeling process by targeting the Sirt1/p300/Yy1/sST2 signaling axis. Collectively, these findings not only highlight sST2 as a promising therapeutic target but also establish a mechanistic rationale for developing novel interventions through pharmacological modulation of the Sirt1/sST2 pathway.