Combined effects of fluoride and arsenite on the expression of Runx-related transcription 2 mRNA in bone of rats

Abstract

Objective To explore the combined effects of fluoride and arsenite on the expression of Runx-related transcription 2 (Runx2) mRNA in bone of Sprague Dawley (SD) rats.Methods Fifty four SD rats were selected[body mass(109.71 ± 10.52)g,half male and half female].3 × 3 Factorial experimental design was used to evaluate the combined effects of fluoride and arsenite on the expression of Runx2 mRNA by random number talbe.Rats were exposed to NaF,NaAsO2 and NaF plus NaAsO2 for 6 months by oral perfusion at gradient doses,respectively:the control group(0 mg/kg NaF + 0.0 mg/kg NaAsO2),the low fluoride group(5 mg/kg NaF),the high fluoride group(20 mg/kg NaF),the low arsenite group(2.5 mg/kg NaAsO2),the high arsenite group(10.0 mg/kg NaAsO2),the low fluoride low arsenite group(5 mg/kg NaF + 2.5 mg/kg NaAsO2),the high fluoride low arsenite group(20 mg/kg NaF + 25 mg/kg NaAsO2),the low fluoride high arsenite group(5 mg/kg NaF + 10.0 mg/kg NaAsO2) and the high fluoride high arsenite group(20 mg/kg NaF + 10.0 mg/kg NaAsO2).The expression of Runx2 mRNA was determined by quantitative real-time RT-PCR.Results The expressions of Runx2 mRNA in the control,low fluoride,high fluoride,low arsenite,high arsenite,low fluoride low arsenite,low fluoride high arsenite,high fluoride low arsenite and high fluoride high arsenite groups were 1.024 ± 0.015,1.377 + 0.014,1.587 ± 0.012,1.182 ± 0.015,1.343 ± 0.010,1.444 ± 0.019,1.504 ± 0.013,1.608 ± 0.013 and 1.714 + 0.009,respectively.The expressions of Runx2 mRNA in experimental groups were higher than those in control group (all P ＜ 0.05),fluoride and arsenite were positively correlated with the expression of Runx2 mRNA(all P ＜ 0.01),and there was a dose-response relationship between Runx2 mRNA and fluoride-arsenite levels.Factorial analysis showed that fluorine or arsenic alone could affect the expression level of Runx2(F =46.967,8.317,all P ＜ 0.05),and there was a interaction between fluorine and arsenic to the expression of Runx2 mRNA (F =105.271,P ＜ 0.01).Conclusion Fluoride or arsenic could promote the expression of Runx2 mRNA in bone of rats; there is an interaction between fluorine and arsenic to the expression of Runx2 mRNA. Key words: Fluorine ; Arsenic ; Runx-related transcription 2