Developmental differences in focal adhesion kinase expression modulate pulmonary endothelial barrier function in...

Area of Science:

• Pulmonary medicine
• Cell biology
• Developmental biology

Background:

• Acute respiratory distress syndrome (ARDS) involves compromised pulmonary endothelial cell (PEC) barrier function.
• Children exhibit higher survival rates from ARDS than adults, suggesting intrinsic protective mechanisms.

Purpose of the Study:

• To investigate developmental differences in PEC barrier function in response to inflammation.
• To determine the role of focal adhesion kinase 1 (FAK1) in these developmental differences.

Main Methods:

• Induction of lung injury in neonatal and adult mice using lipopolysaccharide (LPS).
• Assessment of PEC barrier function in vivo and in vitro.
• Evaluation of FAK1 expression and phosphorylation changes in response to LPS.
• Analysis of FAK silencing and overexpression effects on PEC barrier function.

Main Results:

• LPS induced greater lung permeability and PEC barrier disruption in adult mice compared to neonatal mice.
• LPS increased FAK1 expression in neonatal PECs but increased FAK1 phosphorylation and decreased expression in adult PECs.
• FAK inhibition worsened LPS-induced barrier disruption in adult PECs, while FAK silencing impaired neonatal PEC barrier function.

Conclusions:

• Developmental differences in FAK1 expression and phosphorylation preserve neonatal pulmonary endothelial barrier function during inflammatory injury.
• Intrinsic differences in immature versus adult pulmonary endothelium, particularly FAK1 regulation, may contribute to improved ARDS outcomes in children.