Author: Yan D, Willett TL, Gu XM, Martinez-Mier EA, Sardone L, McShane L, Grynpas M, Everett ET.

Source: Cells Tissues Organs.

Year: 2011

Comment:

The researches conclude:"...prolonged and continuous F exposure leads to strain-dependent and variable- phenotypic responses involving dental enamel development and bone metabolism.  No predictor of bone fluorosis can be found among DF, bone F content, and serum F. The effect of F on bone may depend on the combination of the direct influence on the bone mineral matrix and the biological effects on bone cells via hormone(s)."

Abstract / Excerpt:

“Excessive systemic exposure to fluoride (F) can lead to disturbances in bone homeostasis and dental enamel development. We have previously shown strain-specific responses to F in the development of dental fluorosis (DF) and in bone formation/mineralization. The current study was undertaken to further investigate F responsive variations in bone metabolism and to determine possible relationships with DF susceptibility. Seven-week-old male mice from FVB/NJ, C57BL/6J, C3H/HeJ, A/J, 129S1/SvImJ, AKR/J, DBA/2J, and BALB/cByJ inbred strains were exposed to NaF (0 or 50 ppm as F–) in drinking water for 60 days. Sera were collected for F, Ca, Mg, PO4, iPTH, sRANKL, and ALP levels. Bone marrow cells were subjected to ex vivo cell culture for osteoclast potential and CFU colony assays (CFU-fibroblast, CFU-osteoblast, CFU-erythrocyte/granulocyte/macrophage/megakaryocyte, CFU-granulocyte/macrophage, CFU-macrophage, and CFU-granulocyte). Femurs and vertebrae were subjected to micro-CT analyses, biomechanical testing, and F, Mg, and Ca content assays. DF was evaluated using quantitative fluorescence and clinical criteria. Strain-specific responses to F were observed for DF, serum studies, ex vivo cell culture studies, and bone quality. Among the strains, there were no patterns or significant correlations between DF severity and the actions of F on bone homeostasis (serum studies, ex vivo assays, or bone quality parameters). The genetic background continues to play a role in the actions of F on tooth enamel development and bone homeostasis. F exposure led to variable phenotypic responses between strains involving dental enamel development and bone metabolism. “

Citation:

Yan D, Willett TL, Gu XM, et al. Phenotypic variation of fluoride responses between inbred strains of mice. Cells Tissues Organs (Print). 2011;194(2-4):261-7.