Effect of fluoride on expression of insulin-like growth factor-1 and its receptor of rat osteoblasts / 中国地方病学杂志

ABSTRACT

Objective To explore the influence of fluorine on mRNA and protein expression of the insulin-like growth factor-1 (IGF-1) and its receptor of rat osteoblasts.Methods Osteoblasts were isolated from rat bone by enzyme digestion.Different fluorine concentration [0 (control),10-7,10-6,10-5,10-4,10-3 mol/L] was add to the second generation osteoblasts.The IGF-1 in the culture medium was determined by radioimmunoassay (RIA) at different fluorine concentration and different time (24,48 h).The expression of IGF-1 receptor was measured by the method of fluorescent quantitation PCR and the expression of protein IGF-1 receptor was measured by Western blotting.Results ①With increased dose of fluoride exposure,IGF-1 concentration in the osteoblastic culture medium increased first and then decreased at 24,48 h,respectively.Compared to the control group [(38.83 ± 3.48)ng/L],IGF-1 concentration of the 24 h 10-6 mol/L group[(65.45 ± 4.84)ng/L] was higher,and the difference was statistically significant(P ＜ 0.05).The same result was also shown in the 48 h 10-5 mol/L group [(59.14 ± 1.53)ng/L] to its corresponding control group [(33.79 ± 1.84)ng/L,P ＜ 0.05].②The mRNA expression of IGF-1 receptor of the 24,48 h 10-5 mol/L groups (0.0055 ± 0.0004,0.0262 ± 0.0040) was significantly higher than their corresponding control groups (0.0022 ± 0.0001,0.0073 ± 0.0008,all P ＜ 0.05).③With increased dose of fluoride exposure,the protein expression of IGF-1 receptor increased first and then decreased ;the expression of 24 h 10-5 mol/L group (1.39 ± 0.16) was compared with the corresponding control group (0.86 ±0.12),and the difference was statistically significant (P ＜ 0.05) ; the expression of 48 h every fluorine group was also compared with the corresponding control group,and the difference was not statistically significant(all P＞ 0.05).Conclusions Fluorine can affect the mRNA and protein expression of osteoblastic IGF-1 and its receptor.It indicates that IGFS signal transduction pathways play an important role in fluorine regulation of bone metabolism.