VEGF-C and aortic cardiomyocytes guide coronary artery stem development

Area of Science:

• Developmental Biology
• Cardiovascular Science
• Embryogenesis

Background:

• Coronary arteries (CAs) originate from the aorta at precise locations, essential for preventing myocardial ischemia.
• The embryological mechanisms guiding CA stem formation from peritruncal vessels are not fully understood.
• Deviations in CA stem positioning can result in severe health consequences.

Purpose of the Study:

• To elucidate the molecular and cellular mechanisms governing coronary artery stem formation.
• To investigate the roles of VEGF-C and aortic cardiomyocytes in CA development.
• To understand how developmental defects lead to mispatterned CA stems.

Main Methods:

• Utilized murine models to study coronary artery development.
• Analyzed hearts from VEGF-C deficient and islet 1 (Isl1) heterozygous mice.
• Employed in vitro culture to observe myocardial interactions with the pulmonary artery.

Main Results:

• VEGF-C deficiency led to hypoplastic vessels and abnormal CA stem positioning.
• Aortic cardiomyocytes were identified at CA stem sites in both mouse and human hearts.
• Reduced aortic cardiomyocytes in Isl1 heterozygous mice correlated with abnormal CA stems.
• Outflow tract rotation defects were associated with misplaced aortic cardiomyocytes and ectopic connections.

Conclusions:

• CA stem formation requires initial VEGF-C-driven peritruncal vessel growth.
• Aortic cardiomyocytes play a critical role in mediating vessel-aorta interactions for proper CA stem patterning.
• Disruptions in either VEGF-C signaling or cardiomyocyte development can cause mispatterned CA stems.
• Further study of this developmental niche may offer insights into therapeutic strategies for cardiovascular disease, including vascular regrowth.