Amphiregulin Exerts Proangiogenic Effects in Developing Murine Lungs

Area of Science:

• Developmental Biology
• Pulmonary Medicine
• Cellular Biology

Background:

• Bronchopulmonary dysplasia (BPD) is characterized by interrupted lung angiogenesis, with limited druggable targets.
• Amphiregulin (Areg) is a growth factor involved in cell proliferation, differentiation, migration, survival, and repair.
• The role of Areg in endothelial cell (EC) homeostasis during lung development, particularly under hyperoxia, is not well understood.

Purpose of the Study:

• To investigate the role of Areg in promoting the proangiogenic ability of endothelial cells in developing murine lungs exposed to hyperoxia.
• To determine if Areg signaling is impaired under hyperoxia and if Areg can rescue anti-angiogenic effects.

Main Methods:

• Analysis of Areg expression in lung tissues from neonatal mice exposed to normoxia or hyperoxia.
• Genetic loss-of-function and pharmacological gain-of-function studies in fetal murine lung ECs under normoxia and hyperoxia.
• Assessment of Areg mRNA levels, Areg+ cells, epidermal growth factor receptor (EGFR) expression, and extracellular signal-regulated kinase (ERK) activation.

Main Results:

• Hyperoxia increased Areg mRNA and Areg+ cell counts in whole lungs.
• Areg expression increased in lung ECs under hyperoxia, but its receptor, EGFR, decreased, indicating reduced Areg signaling.
• Areg deficiency exacerbated hyperoxia-induced anti-angiogenic effects, while Areg treatment enhanced ERK activation and promoted angiogenesis.

Conclusions:

• Areg signaling is impaired in lung endothelial cells under hyperoxia.
• Areg plays a protective role against hyperoxia-induced anti-angiogenic effects.
• Areg promotes endothelial cell tubule formation in developing murine lungs exposed to hyperoxia, highlighting its therapeutic potential.