PDGF-AB Reduces Myofibroblast Differentiation Without Increasing Proliferation After Myocardial Infarction

Area of Science:

• Cardiovascular Biology
• Regenerative Medicine
• Fibrosis Research

Background:

• Myocardial infarction (MI) leads to cardiac fibroblast activation and fibrosis.
• Platelet-derived growth factors (PDGFs) are implicated in fibroblast proliferation and fibrosis post-MI.
• Previous studies suggest PDGFs improve cardiac function post-MI without exacerbating fibrosis.

Purpose of the Study:

• To investigate the precise effects of PDGF isoforms on cardiac fibroblasts and post-MI cardiac remodeling.
• To elucidate the molecular mechanisms underlying PDGF's action in the context of MI.
• To evaluate the therapeutic potential of PDGF-AB in modulating cardiac scar maturation.

Main Methods:

• In vitro treatment of human cardiac fibroblasts with PDGF isoforms followed by RNA sequencing.
• In vivo studies using mouse and pig myocardial infarction models with PDGF-AB infusion.
• Transcriptomic analysis (RNA sequencing) of cardiac tissue post-MI.

Main Results:

• PDGFs reduced myofibroblast differentiation and downregulated cell cycle pathways in human cardiac fibroblasts.
• PDGF-AB infusion in MI models increased cell-cell interactions, reduced myofibroblast differentiation, and accelerated scar formation without affecting proliferation.
• PDGF-AB decreased inflammatory cytokines and altered transcript variants and long noncoding RNA expression in cell cycle pathways in pig hearts post-MI.

Conclusions:

• PDGF-AB exhibits a unique role in modulating cardiac fibroblast behavior post-MI, reducing differentiation rather than proliferation.
• PDGF-AB therapy accelerates cardiac scar maturation, suggesting a role in scar remodeling.
• PDGF-AB holds therapeutic promise for improving cardiac function by manipulating post-MI scar development.