Multiple roles for Sox2 in the developing and adult mouse trachea

Area of Science:

• Developmental Biology
• Molecular Biology
• Respiratory Medicine

Background:

• The embryonic foregut gives rise to the esophagus, trachea, and lungs, which develop distinct tissue phenotypes.
• Sox2 is a known transcription factor essential for foregut morphogenesis and esophageal development.

Purpose of the Study:

• To investigate the role of the transcription factor Sox2 in the development and maintenance of the trachea and lungs.
• To determine Sox2's function in epithelial cell differentiation and repair in the airways.

Main Methods:

• Conditional deletion of the Sox2 gene in specific embryonic epithelial domains using Nkx2.5-Cre and Sox2 floxed alleles.
• Analysis of respiratory distress, tracheal morphology, and epithelial cell populations (mucus, basal stem, ciliated, Clara cells) in mutant mice.
• Assessment of epithelial cell proliferation and in vivo repair capacity in adult mice lacking Sox2.

Main Results:

• Conditional deletion of Sox2 in the embryonic trachea and lung primordia resulted in embryonic lethality due to respiratory distress, likely from abnormal cartilage development and defective epithelial-mesenchymal interactions.
• Mutant mice exhibited shortened tracheas and altered tracheal epithelium with increased mucus-producing cells and decreased basal stem, ciliated, and Clara cells.
• Sox2 deficiency impaired the differentiation of embryonic airway progenitors and reduced the proliferative and repair capacity of adult airway epithelial cells, including basal stem cells.

Conclusions:

• Sox2 is essential for normal trachea and lung development, influencing cartilage formation and epithelial cell differentiation.
• Sox2 plays a critical role in maintaining the adult trachea epithelium, supporting stem cell function and tissue repair.
• These findings highlight the multifaceted roles of Sox2 in both the development and adult homeostasis of the trachea and airways.