NFIB regulates embryonic development of submandibular glands

Area of Science:

• Developmental Biology
• Molecular Biology
• Genetics

Background:

• Salivary gland development involves distinct stages, including terminal differentiation.
• Nuclear factor I B (NFIB) is a transcription factor vital for organ system development.
• The role of NFIB in salivary gland terminal differentiation remains largely unknown.

Purpose of the Study:

• To investigate the function of NFIB in mouse submandibular gland (SMG) development.
• To determine if NFIB influences SMG branching morphogenesis or cell differentiation.

Main Methods:

• Comparative analysis of SMGs from wild-type and Nfib-deficient mice (Nfib (-/-)) at embryonic days E16.5 and E18.5.
• Histological examination of branching morphogenesis and cell organization.
• Immunohistochemical analysis for markers of cell differentiation, apicobasal polarity (ZO-1, E-cadherin), and secretory function (SMGC).

Main Results:

• NFIB deficiency did not affect SMG branching morphogenesis.
• Nfib (-/-) mice exhibited disorganized inner terminal tubule cells at E16.5.
• At E18.5, Nfib (-/-) SMGs failed to differentiate into tubule secretory cells, showing disorganized polarity and loss of SMGC secretion, despite maintaining general apicobasal polarity.

Conclusions:

• NFIB is dispensable for SMG branching morphogenesis.
• NFIB plays a critical role in the terminal differentiation of tubule ductal cells into secretory cells in the mouse SMG.
• NFIB is essential for establishing proper cell organization, polarity, and secretory function during late-stage SMG development.