Semaglutide reduced heart muscle damage after ischemia-reperfusion injury in mice by inhibiting ferroptosis in cardiomyocytes through activation of the PKC pathway and downregulation of S100A9, identified as the target gene via RNA sequencing.
S100A9 identified as target geneRNA sequencing revealed S100A9 as semaglutide's specific target in the heart — PKC pathway activation suppresses S100A9, blocking iron-dependent cell death (ferroptosis) in heart muscle after ischemia-reperfusion.
What the researchers found
In mice with myocardial ischemia-reperfusion (45 min LAD ligation + 24 h reperfusion):
- Semaglutide enhanced cardiac function recovery (ultrasound assessment)
- Reduced cardiac fibrosis (Masson's staining)
- Mitigated oxidative stress in cardiomyocytes
- Inhibited ferroptosis in cardiomyocytes
- RNA sequencing identified S100A9 (S100 calcium-binding protein A9) as the target gene
- In vitro confirmation: semaglutide activated PKC (Protein Kinase C) pathway, which decreased S100A9 expression, thereby inhibiting ferroptosis
The PKC → S100A9 → ferroptosis inhibition axis represents a novel mechanism for semaglutide's cardioprotective effects.
Why it matters
Heart attacks remain the leading cause of death globally, and ischemia-reperfusion injury is an unavoidable consequence of the life-saving procedure of reopening blocked arteries. There is currently no approved drug specifically targeting reperfusion injury. The discovery that semaglutide — already widely prescribed and well-characterized for safety — protects against this injury through a specific molecular pathway could lead to its use as a cardioprotective agent during heart attack intervention, without requiring development of an entirely new drug.
How the study worked
A mouse model of myocardial ischemia-reperfusion was created by ligating the left anterior descending coronary artery for 45 minutes followed by 24 hours of reperfusion. Cardiac function was assessed by small animal ultrasound; fibrosis by Masson's staining; oxidative stress and ferroptosis markers were measured in vivo. RNA sequencing was performed to identify semaglutide's target genes. The mechanism was validated in vitro by studying PKC pathway activation, S100A9 expression, and ferroptosis in cardiomyocyte cell cultures.
What this study cannot tell us
The mouse ischemia-reperfusion model uses a single artery ligation, which may not perfectly replicate human heart attacks involving complex coronary anatomy and atherosclerotic disease. Semaglutide timing relative to the injury is not clearly specified — whether it was given before, during, or after ischemia matters clinically. The RNA sequencing identified S100A9 as the primary target, but other pathways may also contribute. The study did not include a survival analysis. The in vitro validation used isolated cardiomyocytes, which lack the complex multicellular environment of the heart.
How to read the evidence
This is a preclinical mechanistic study combining an established cardiac ischemia-reperfusion mouse model with unbiased RNA sequencing for target identification and in vitro pathway validation. The multi-method approach is rigorous for preclinical research, though all findings are in animal/cell systems.
When this study was published
Published in 2025, this is a very current study contributing to the rapidly expanding understanding of GLP-1 drugs' cardioprotective mechanisms beyond metabolic effects.
The bigger picture
This is the second study in this batch showing semaglutide inhibits ferroptosis — the earlier liraglutide kidney study found ferroptosis inhibition via the Fsp1-CoQ10-NAD(P)H pathway, while this cardiac study identifies the PKC-S100A9 axis. Different organs, different pathways, same outcome: GLP-1 drugs appear to be broad-spectrum ferroptosis inhibitors. Ferroptosis is increasingly recognized as a key cell death mechanism in heart attacks, strokes, and organ injuries. GLP-1 drugs' ability to block this process across multiple tissues may explain much of their observed organ protection beyond glucose control.
Questions still open
- Could semaglutide be administered during cardiac catheterization to reduce reperfusion injury in real heart attack patients?
- Do patients already taking semaglutide for diabetes have smaller heart attacks or better recovery when they experience cardiac events?
- Is the PKC-S100A9 ferroptosis pathway specific to the heart, or does semaglutide use this mechanism in other organs too?
Common questions
Could semaglutide help protect the heart during a heart attack?
What is ferroptosis and why does it matter for heart attacks?
Read the original research
Semaglutide attenuates myocardial ischemia-reperfusion injury by inhibiting ferroptosis of cardiomyocytes via activation of PKC-S100A9 axis.
Frontiers in pharmacology, 16, 1529652
Citation
Liu, Yan; Li, Zixuan; Xu, Xinhe; Zou, Yan; Zhang, Miaomiao; Chen, Yingyu; Zhu, Wenwu; Han, Bing. (2025). Semaglutide attenuates myocardial ischemia-reperfusion injury by inhibiting ferroptosis of cardiomyocytes via activation of PKC-S100A9 axis.. Frontiers in pharmacology, 16, 1529652. https://doi.org/10.3389/fphar.2025.1529652