Novel Cardiokine GDF3 Predicts Adverse Fibrotic Remodeling After Myocardial Infarction.

Area of Science:

• Cardiovascular Biology
• Regenerative Medicine
• Molecular Cardiology

Background:

• Myocardial infarction (MI) triggers a repair process leading to fibrotic scarring.
• Excessive fibrosis post-MI impairs cardiac function and recovery.
• Mechanisms driving cardiac fibrosis are not fully understood.

Purpose of the Study:

• To investigate the role of cardiac stromal cells in regulating fibroblast expansion after MI.
• To identify specific secreted factors mediating this paracrine action.
• To assess the potential of these factors as biomarkers for adverse cardiac remodeling.

Main Methods:

• Bioinformatic secretome analysis of cardiac stromal PW1+ cells post-MI.
• Functional assays to screen for fibroblast proliferation-inducing secreted proteins.
• Expression analysis in mouse and human tissues and plasma.
• Correlation of circulating protein levels with cardiac remodeling in MI patients.

Main Results:

• Cardiac stromal cells alter paracrine signaling post-MI, promoting fibroblast proliferation.
• Growth differentiation factor 3 (GDF3) was identified as a key upregulated secreted factor.
• GDF3 directly stimulates fibroblast proliferation via activin-receptor-like kinases.
• Increased GDF3 levels were detected in mouse and human plasma post-MI.
• Higher plasma GDF3 levels in patients correlated with adverse remodeling 6 months post-MI.

Conclusions:

• Cardiac stromal cells mediate profibrotic effects through secreted cardiokines like GDF3.
• GDF3 is a potential biomarker for predicting adverse fibrotic remodeling after MI.
• This study elucidates a novel mechanism in post-MI cardiac fibrosis.