Clinical and microstructural aberrations of enamel of deciduous and permanent teeth in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy

Autoimmunity, Not a Developmental Defect, is the Cause for Subfertility of Autoimmune Regulator (Aire) Deficient Mice

Autoimmune regulator's (AIRE) best characterized role is in the generation immunological tolerance, but it is also involved in many other processes such as spermatogenesis. Loss-of-function mutations in AIRE cause a disease called autoimmune polyendocrinopathy, candidiasis and ectodermal dystrophy (APECED; also called autoimmune polyendocrinopathy syndrome type 1, APS-1) that is dominated by various autoimmune manifestations, mainly endocrinopathies. Both patients with APECED and Aire(-/-) mice suffer from varying levels of infertility, but it is not clear if it is a result of an autoimmune tissue damage or more of a developmental defect. In this study, we wanted to resolve whether or not the reduced fertility of Aire(-/-) mice is dependent on the adaptive immune system and therefore a manifestation of autoimmunity in these mice. We generated lymphopenic mice without Aire expression that were devoid of the autoimmune manifestations previously reported in immunocompetent Aire(-/-) mice. These Aire(-/-) Rag1(-/-) mice regained full fertility. This confirms that the development of infertility in Aire(-/-) mice requires a functional adaptive immune system. We also show that only the male Aire(-/-) mice are subfertile, whereas Aire(-/-) females produce litters normally. Moreover, the male subfertility can be adoptively transferred with lymphocytes from Aire(-/-) donor mice to previously fertile lymphopenic Aire(-/-) recipients. Our data show that subfertility in Aire(-/-) mice is dependent on a functional adaptive immune system thus confirming its autoimmune aetiology.

Effect of high phosphorus diet on tooth microstructure of rodent incisors

Enamel hypoplasia and disruption of dentinogenesis are the most common abnormalities of development and mineralization of human teeth. Several reports are available in the literature on the influence of dietary calcium on the formation of human and rodent tooth; however, the information about the influence of dietary phosphorus on the tooth formation is scarce. The aim of the present investigation was to examine the chronic effect of high phosphorus diet and improper dietary calcium to phosphorus ratio on the mandibular incisor microstructure in a hystricomorph rodent--Octodon degu--using macroscopic observation, histopathological examination, transmission and scanning electron microscopy. The present study shows that enamel and dentin development is disturbed under high phosphorus diet and improper calcium to phosphorus ratio. Disturbed mineral metabolism resulted in enamel depigmentation, enamel hypoplasia, enamel pitting and altered dentin morphology. The results suggest that more attention should be focused on dietary phosphorus content when facing altered tooth structure in young patients with deciduous or permanent dentition. Furthermore, we showed that degus can be used as an experimental animal model for the study of the developmental teeth disturbances.