E2F1 suppresses cardiac neovascularization by down-regulating VEGF and PlGF expression

Area of Science:

• Cardiovascular Biology
• Molecular Biology
• Transcription Factors

Background:

• E2F transcription factors (E2F) are key regulators of cell cycle, growth, and death.
• The specific role of E2F1 in cardiac neovascularization following myocardial infarction (MI) remains largely unexplored.

Purpose of the Study:

• To investigate the role of E2F1 in cardiac neovascularization and functional recovery after MI.

Main Methods:

• Myocardial infarction was induced in wild-type (WT) and E2F1 knockout (E2F1(-/-)) mice.
• Cardiac function, infarct size, capillary density, endothelial cell (EC) proliferation, and apoptosis were assessed.
• Vascular Endothelial Growth Factor (VEGF) and Placental Growth Factor (PlGF) levels, as well as p53 levels, were measured.
• In vitro studies using cardiac fibroblasts examined hypoxia-induced growth factor up-regulation and E2F1's interaction with p53.

Main Results:

• E2F1(-/-) mice exhibited improved cardiac function and reduced infarct size compared to WT mice.
• Enhanced capillary density, EC proliferation, and higher VEGF/PlGF levels were observed in E2F1(-/-) mice.
• VEGF receptor 2 (VEGFR2) signaling blockade abolished these beneficial effects.
• E2F1 overexpression suppressed PlGF and VEGF up-regulation, with E2F1 interacting with and stabilizing p53 under hypoxia.

Conclusions:

• E2F1 significantly limits cardiac neovascularization and functional recovery post-MI.
• E2F1 suppresses VEGF and PlGF up-regulation through both p53-dependent and -independent pathways.
• Targeting E2F1 may represent a novel therapeutic strategy for enhancing cardiac repair after MI.