# Multi-omics analysis reveals STING activation mediates NLRP3-related pyroptosis and exacerbates myocardial ischemia-reperfusion injury

## TL;DR

This study shows that STING activation worsens heart damage after blood flow is restored following a heart attack, by triggering inflammation and cell death.

## Contribution

The study identifies STING as a mediator of NLRP3-related pyroptosis in myocardial ischemia-reperfusion injury, offering a new therapeutic target.

## Key findings

- STING activation increases oxidative stress and NLRP3 inflammasome activity, worsening heart injury.
- STING inhibition reduces inflammation and improves cardiac function in I/R models.
- Pyroptosis-related genes are dysregulated in I/R, with elevated scores in cardiomyocytes and inflammatory cells.

## Abstract

Myocardial ischemia-reperfusion injury (I/R) significantly exacerbates cardiomyocyte damage post-recanalization therapy in acute myocardial infarction. Pyroptosis and the NLRP3 inflammasome are crucial in I/R, yet the precise mechanism remains unclear.

Transcriptomics, proteomics, and single-cell transcriptomics were employed to examine cellular subtype changes and pyroptosis-associated gene regulation in I/R. Differential pyroptosis-related genes were identified from transcriptomics data and validated with proteomics. Single-cell RNA sequencing assessed pyroptosis levels and intercellular communication. Mouse myocardial I/R and human cardiomyocyte hypoxia/reoxygenation (H/R) models were used to explore STING overexpression/silencing effects on NLRP3 inflammasome activation, oxidative stress, and cellular injury.

Pyroptosis-related genes were significantly dysregulated, implicating multiple inflammatory pathways. Single-cell analyses revealed increased granulocytes, macrophage infiltration, cardiomyocyte injury, and enhanced pyroptosis scores post-I/R. Cardiomyocytes, endothelial cells, and fibroblasts exhibited increased pyroptosis and inflammatory cell-cell interactions. Animal studies indicated significant declines in cardiac function and increased oxidative stress and inflammation post-I/R. STING activation (SR717) worsened cardiac function, enhanced ROS production, and elevated myocardial injury markers; STING inhibition (H151) markedly mitigated these effects. Correspondingly, the cGAS-STING pathway and NLRP3 inflammasome factors were significantly upregulated post-I/R, exacerbated by STING agonists and alleviated by STING inhibitors. Cellular studies confirmed that STING overexpression intensified oxidative stress and pyroptosis, effects reversed by STING knockdown and blocked by NLRP3 inhibitor MCC950.

STING activation contributes to oxidative stress and NLRP3 inflammasome–associated pyroptosis during I/R. Targeting the STING-NLRP3 axis may represent a potential strategy to reduce myocardial injury after ischemia-reperfusion.