Basic fibroblast growth factor is upregulated in hibernating myocardium

Area of Science:

• Cardiovascular Research
• Molecular Biology
• Regenerative Medicine

Background:

• Myocardial ischemia triggers the upregulation of angiogenic growth factors like basic fibroblast growth factor (bFGF).
• Existing animal models often lack the stability to study ischemia beyond a few weeks.
• A stable porcine model of hibernating myocardium allows for examination of long-term molecular changes.

Purpose of the Study:

• To investigate basic fibroblast growth factor (bFGF) protein levels in hibernating myocardium.
• To assess bFGF levels at baseline and at 3 and 6 months post-myocardial ischemia.
• To understand the sustained endogenous response to myocardial ischemia.

Main Methods:

• Eighteen miniswine were utilized, with 6 serving as controls.
• Myocardial ischemia was induced in 12 pigs via left circumflex artery occlusion, confirmed by PET and dobutamine stress echocardiography.
• Basic FGF protein levels were quantified using ELISA in myocardial tissue samples harvested at 3 and 6 months post-occlusion.

Main Results:

• Basic FGF protein levels were significantly elevated (threefold) at 3 months post-ischemia compared to controls (P < 0.05).
• At 6 months, bFGF levels showed a sixfold increase relative to control animals (P < 0.05).
• A significant increase was observed between the 3-month and 6-month groups (P < 0.05).

Conclusions:

• Endogenous bFGF production is significantly upregulated in hibernating porcine myocardium at both 3 and 6 months post-ischemia.
• Sustained elevation of bFGF suggests a long-term adaptive response to chronic myocardial ischemia.
• Further research is needed to determine the effects of exogenous bFGF delivery in the context of varying endogenous growth factor levels.