TGFβ3 regulates periderm removal through ΔNp63 in the developing palate

Area of Science:

• Developmental Biology
• Molecular Biology
• Genetics

Background:

• The periderm, an embryonic epithelium, must be removed for proper palate fusion.
• Failure in periderm removal leads to cleft palate, a common birth defect.
• Transforming growth factor β3 (TGFβ3) is expressed during periderm degeneration, but its role is unclear.

Purpose of the Study:

• To investigate the association between TGFβ3 signaling and IRF6/ΔNp63 genes in palate development.
• To elucidate the role of TGFβ3 in periderm desquamation during palatogenesis.

Main Methods:

• Biochemical analysis of palatal sections from TGFβ3 (-/-), ΔNp63 (-/-), and wild-type embryos.
• Gene activity and protein expression assays in primary medial edge epithelia (MEE) cells.
• Analysis of the interplay between TGFβ3, IRF6, and ΔNp63 during embryonic palate development.

Main Results:

• TGFβ3 signaling is required to repress ΔNp63, which is essential for periderm desquamation.
• In TGFβ3 (-/-) embryos, inadequate periderm removal causes cleft palate due to failed palatal seam formation.
• In ΔNp63 (-/-) embryos, cleft palate results from premature fusion, indicating a role in regulating fusion timing.

Conclusions:

• Functional TGFβ3 signaling is critical for repressing ΔNp63 and coordinating periderm shedding.
• The TGFβ3-ΔNp63 axis is a key regulator of epithelial adhesion and differentiation during palate development.
• Dysregulation of this pathway contributes to cleft palate etiology.