Platelets play an essential role in murine lung development through Clec-2/podoplanin interaction

Area of Science:

• Developmental Biology
• Hematology
• Pulmonology

Background:

• Platelets are known for roles in hemostasis and thrombosis.
• Emerging evidence suggests platelet involvement in inflammation and metastasis.
• The role of platelets in solid organ development remained largely unexplored.

Purpose of the Study:

• To investigate the role of platelets in lung development.
• To elucidate the molecular mechanisms underlying platelet-mediated lung development.

Main Methods:

• Utilized knockout mouse models with specific gene deletions (Clec-2, podoplanin).
• Analyzed lung morphology, cellular differentiation (myofibroblasts, mesothelial cells), and signaling pathways (TGF-β).
• Induced thrombocytopenia and growth factor depletion in fetal mice.

Main Results:

• Clec-2 deletion in platelets caused severe lung malformation, respiratory failure, and neonatal lethality.
• Absence of alveolar duct myofibroblasts and abnormal differentiation of lung mesothelial cells were observed.
• Podoplanin expression in lymphatic endothelial cells and its interaction with Clec-2 are critical for lung development, mimicking Clec-2 deficiency.

Conclusions:

• Platelet-derived Clec-2 interaction with podoplanin on lymphatic endothelial cells is essential for normal lung development.
• This interaction promotes lung mesothelial cell differentiation into myofibroblasts via TGF-β signaling.
• Disruption of this pathway leads to severe lung defects and neonatal lethality.