Adam10-dependent Notch signaling establishes dental epithelial cell boundaries required for enamel formation.
iScience 2022;
25:105154. [PMID:
36193048 PMCID:
PMC9526176 DOI:
10.1016/j.isci.2022.105154]
[Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/27/2022] [Accepted: 09/14/2022] [Indexed: 11/24/2022] Open
Abstract
The disintegrin and metalloproteinase Adam10 is a membrane-bound sheddase that regulates Notch signaling and ensures epidermal integrity. To address the function of Adam10 in the continuously growing incisors, we used Keratin14Cre/+;Adam10fl/fl transgenic mice, in which Adam10 is conditionally deleted in the dental epithelium. Keratin14Cre/+;Adam10fl/fl mice exhibited severe abnormalities, including defective enamel formation reminiscent of human enamel pathologies. Histological analyses of mutant incisors revealed absence of stratum intermedium, and severe disorganization of enamel-secreting ameloblasts. In situ hybridization and immunostaining analyses in the Keratin14Cre/+;Adam10fl/fl incisors showed strong Notch1 downregulation in dental epithelium and ectopic distribution of enamel-specific molecules, including ameloblastin and amelogenin. Lineage tracing studies using Notch1CreERT2;R26mT/mG mice demonstrated that loss of the stratum intermedium cells was due to their fate switch toward the ameloblast lineage. Overall, our data reveal that in the continuously growing incisors the Adam10/Notch axis controls dental epithelial cell boundaries, cell fate switch and proper enamel formation.
ADAM10 deletion in the dental epithelium causes the formation of defective enamel
ADAM10 deletion leads to loss of stratum intermedium and Notch1 expression
ADAM10 deletion leads to stratum intermedium-to-ameloblast cell fate switch
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