Histological Analysis of Dentinogenesis Imperfecta in Slc39a13/Zip13 Knockout Mice

This study focused on the abnormality of dentin matrix to clarify the pathogenesis of human dentinogenesis imperfecta (DI). Dentin matrix of mandibular molars from wild type (Zip 13+/+) and Slc39a/Zip 13 knockout (KO) mice were examined histologically. Hematoxylin and eosin, as well as silver staining, were used for light microscopy. Samples were also observed under backscattered and transmission electron microscopy. Immunohistochemistry using type I collagen was also carried out. Results showed that Zip 13-KO mice exhibited 1) lamellated dentin matrix with accentuated incremental lines under the light microscope, 2) abnormal collagen fibers and round shape collagen molecules in transmission electron microscope, and 3) unusual immunoreaction to collagen type I. The similarity in the histological features of dentin in Zip 13-KO mice to human DI indicates that Zip13-KO mice may be used as models for investigating the mechanism of human DI.