Abstract
In this study, in order to clarify the host genetic factors that influence dental caries susceptibility, we examined the role of host genetic factors by comparing whole genome expression and salivary protein levels using C57BL/6 (B6) mice, which showed high dental caries susceptibility, and C3H and B6-Chr2C3H mice, which show low dental caries susceptibility. We analyzed gene expression in the submandibular gland by genechip microarray using submandibular glands from B6, C3H and B6-Chr2C3H mice. Two genes that showed the top expression in each category among the 3 strains were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and quantitative Real-Time PCR analyses. We also analyzed saliva protein concentration by the Bradford method. On microarray analysis, the Tmem87A and Capn3 genes showed the greatest differences in gene expression among the 3 strains. These genes were confirmed by RT-PCR and quantitative Real-Time PCR, and protein concentrations in C3H, B6-Chr2C3H and B6 were 0.210μg/ml, 0.177μg/ml and 0.217μg/ml, respectively. Protein concentrations in B6-Chr2C3H were significantly lower than in B6 and C3H. Thus, Tmem87A and Capn3 may be related to differences in caries susceptibility observed with the Substituted of chromosome 2 in mice. Moreover, protein levels in saliva do not affect caries susceptibility in 3 strains. This suggests that differences in caries sensitivity of B6, C3H and B6-Chr2C3H are related to differences in water permeability in the salivary glands.
