IADR Abstract Archives
NFIB Regulates Mouse Embryonic Development of Submandibular Glands
Objectives: NFIB (Nuclear Factor I B) is a NFI transcription factor family member, which is essential for the development of a variety of organ systems. Salivary gland development occurs through several stages including: pre-bud, bud, pseudoglandular, canalicular and terminal.
Although many studies have been done to understand mouse submandibular gland (SMG) branching morphogenesis, little is known about SMG cell differentiation during the terminal stages. The objective of this research was to determine the role of NFIB during SMG development.
Methods: In this study we analyzed SMG from wild type and Nfib deficient mice (Nfib-/-). Hematoxylin and eosin staining, toluidine blue tissue staining, immunohistochemistry, immunofluorescent microscopy, and real time PCR were used to determine localization and organization of tubule cells, polarization of proteins, and gene expression levels, respectively.
Results: At embryonic (E) day 18.5, SMG from wild type mice showed duct branching morphogenesis and differentiation of tubule ductal cells into tubule secretory cells. In contrast, SMG from Nfib-/- mice at E18.5 failed to differentiate into tubule secretory cells while branching morphogenesis was unaffected. SMG from wild type mice at E16.5 displayed well-organized cuboidal inner terminal tubule cells. However, SMG from Nfib-/- at E16.5 displayed disorganized inner terminal tubule cells. SMG from wild type mice at E18.5 became fully differentiated as indicated by a high degree of apicobasal polarization (i.e., presence of apical ZO-1 and basolateral E-cadherin) and columnar shape. Furthermore, SMG from wild type mice at E18.5 expressed the protein SMGC, a marker for tubule secretory cells. However, SMG from Nfib-/- mice at E18.5, showed apicobasal polarity but it was disorganized and lost their ability to secrete SMGC.
Conclusions: These findings indicate that the transcription factor NFIB is not required for branching morphogenesis, but plays a key role in tubule cell differentiation during mouse SMG development.
Although many studies have been done to understand mouse submandibular gland (SMG) branching morphogenesis, little is known about SMG cell differentiation during the terminal stages. The objective of this research was to determine the role of NFIB during SMG development.
Methods: In this study we analyzed SMG from wild type and Nfib deficient mice (Nfib-/-). Hematoxylin and eosin staining, toluidine blue tissue staining, immunohistochemistry, immunofluorescent microscopy, and real time PCR were used to determine localization and organization of tubule cells, polarization of proteins, and gene expression levels, respectively.
Results: At embryonic (E) day 18.5, SMG from wild type mice showed duct branching morphogenesis and differentiation of tubule ductal cells into tubule secretory cells. In contrast, SMG from Nfib-/- mice at E18.5 failed to differentiate into tubule secretory cells while branching morphogenesis was unaffected. SMG from wild type mice at E16.5 displayed well-organized cuboidal inner terminal tubule cells. However, SMG from Nfib-/- at E16.5 displayed disorganized inner terminal tubule cells. SMG from wild type mice at E18.5 became fully differentiated as indicated by a high degree of apicobasal polarization (i.e., presence of apical ZO-1 and basolateral E-cadherin) and columnar shape. Furthermore, SMG from wild type mice at E18.5 expressed the protein SMGC, a marker for tubule secretory cells. However, SMG from Nfib-/- mice at E18.5, showed apicobasal polarity but it was disorganized and lost their ability to secrete SMGC.
Conclusions: These findings indicate that the transcription factor NFIB is not required for branching morphogenesis, but plays a key role in tubule cell differentiation during mouse SMG development.