Gene expression profiles of the incisor pulp tissue during fluorosis

Wu Y, Hao Y-Q, Li J-Y, Zhou X-D. Gene expression profiles of the incisor pulp tissue during fluorosis. International Endodontic Journal. Abstract Aim  To examine gene expression levels within the cells of dental pulp tissue in fluorotic rats and normal subjects and to identify fluoride-susceptible genes. Methodology  Female wistar rats were given 0.16 (control) or 100 parts per 106 fluoride ion in their drinking water. After 3 months, the teeth in the fluoride-exposed animals showed signs of fluorosis. The animals were killed, and RNA was extracted from incisor pulp tissue and pooled into three fluorosis and three control pools. The females were analysed for gene expression profiles using microarray analysis and semi-quantitative reverse transcriptase polymerase chain reaction (Sq-RT-PCR). Results  Of the 26 962 probe sets, duplicate hybridisation data indicated that 5443 genes were detected as being present by both targets. Two hundred and forty seven genes, that is 4.53% of detected genes, were 1.5-fold or greater differentially expressed after fluoride treatment. Three interesting genes, dentine matrix protein 1, dentine sialophosphoprotein and Cadherin-11, were confirmed as being down-regulated by Sq-RT-PCR. Conclusions  The gene expression levels in rat pulp tissue changed during fluorosis. The gene expression profiles between the fluorotic model and the normal group will help to understand the multiple pathogenic mechanisms for the altered mineralization patterns observed in fluorotic dentine.