RÉSUMÉ
Objective To determine the impact of fluorine and aluminum,and both action combined on the number of rat osteoclasts and bone resorption cultured in vitro and to explore its mechanisms.Methods The osteoclasts and bone marrow stromal cells (BMSCs) isolated from long bone of new born rats were cultured,respectively,in TC199 medium (containing 10％ fetal bovine serum) with fluoride,aluminum and fluoride combined with aluminum.The osteoclasts were inoculated in 96-well culture plate and ivory slice,BMSCs in 6-well culture plate,and culture medium was changed after 2 hours incubation.The cells were divided into control group,fluoride group,aluminum group and fluoride combined with aluminum group; the doses of sodium fluoride were 0,1.0 × 10-4,0,1.0 × 10-4 mol/L and the doses of aluminum chloride were 0,0,1.0 × 10-5,1.0 × 10-5 mol/L,respectively.Tartrate-resistant acid phosphatase (TRAP) staining positive cells were counted under light microscope after TRAP staining on the 5th day and the pit formed in ivory slices were measured by histomorphometry after staining with toludine blue.The expression of osteoprotegerin(OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) was detected by real-time fluorescence quantitative PCR in BMSCs after 8 h treatment.Results ① Fluoride,aluminum and the interactive effects of fluoride and aluminum all had impact on the numbers of osteoclasts (F =7.15,6.56 and 7.98,respectively,all P ＜ 0.05).The numbers of osteoclasts in fluoride group,aluminum group and fluoride combined with aluminum group[(136.9 ± 22.99),(135.4 ± 23.5),(163.0 ± 24.4) per well] were higher than that in the control group[(92.5 ± 22.1) per well,all P ＜ 0.05].② Fluoride,aluminum and the interactive effects of fluoride and aluminum all had impact on the resorption pit area on ivory slices(F =10.47,12.64,14.29,respectively,all P ＜ 0.05).The resorption pit area on ivory slices in fluoride group,aluminum group and fluoride combined with aluminum group[(0.242 ± 0.031),(0.293 ± 0.026),(0.333 ± 0.016)mm2 per slice] was higher than that in the control group [(0.088 ± 0.030)mm2 per slice,all P ＜ 0.05].③Fluoride,aluminum and the interactive effects of fluoride and aluminum all had impact on the expression ratios of RANKL/OPG in BMSCs (F =8.15,15.38,23.59,respectively,all P ＜ 0.05).The expression ratios of RANKL/OPG in BMSCs in fluoride group,aluminum group and fluoride combined with aluminum group [(193.98 ± 137.93)％,(326.11 ± 176.78)％,(599.84 ± 275.82)％] were higher than that in the control group[(100.00 ± 56.02)％,all P ＜ 0.05].Conclusions Both fluoride and aluminum can cause increase in the number of osteoclasts in vitro and promote cell differentiation and bone resorption activity,which may be related to increased expression ratio of RANKL/OPG mRNA in BMSCs.The stimulating effects of fluoride on osteoclasts differentiation and bone resorption is enhanced by aluminum.
RÉSUMÉ
Objective To investigate the levels of trace elements such as fluorine(F), and aluminium (Al)etc. of osteomalacia malformation children and to make etiological diagnosis in reference with clinical manifestations.Methods Urine and occipitalia hairs of 14 diseased children(patient group) from endemic fluorosis area and 13 healthy children(control group) from non-endemic area were included in the study on November, 2008, and contents of 10 elements of fluorine(F), aluminum(Al), chromium(Cr), manganese(Mn), ferrum(Fe), cuprum(Cu), zinc(Zn), arsenic (As), selenium(Se), strontium(Sr), and barium(Ba) were tested. The data were analyzed with medical soft package PEMS 3.1. Results Urinary contents of F, Al, Mn, Cu, Sr, and Se(1.18 mg/L, 112.6 μg/L,6.62,29.86 mg/L, 177.5,4.23 ng/L) in patient group were significantly different from those in control group (0.48,47.1,2.04,16.61 mg/L, 55.17,15.52 ng/L, t = 4.592,2.486,4.850,2.210 2.078,2.912, all P＜ 0.05); Hair contents of Al, Mn, As, Sr, Ba, Fe, and Se in patient group(59.27,5.26,0.96,1.50,1.29,297.13,0.45 mg/kg)were significantly different from those of control group( 18.69,0.72,1.09,0.62,0.68,69.02,1.323 mg/kg, t = 4.583,6.318,3.309,2.704,5.606,6.294, all P ＜ 0.05); in patient group, the correlation coefficients of urinary Fe to Al,Zn, As, and Se were all bigger tan 0.662(all P＜ 0.05), those of urinary Se to Mn, Ba, Cu, Zn, Sr, and As were all bigger than 0.694(all P＜ 0.05), those among urinary Mn, Sr, As, and Ba were bigger than 0.550(all P＜0.05), those of hair Al to Mn, Cr, Fe, and Cu were bigger than 0.732(all P＜ 0.05), those of hair Ba to Mn,Cr, Fe, and Sr, and of hair Mn to Cr and Fe, and those between Cr and As, between Cu and Sr were all bigger than 0.686 (all P ＜ 0.05). In control group, the correlation coefficients of urinary Cu to Zn, Se, and Ba, those of Zn to Se and Ba, and those of Cr to Mn and Ba were all bigger than 0.516(all P ＜ 0.05), those of hair Al to Mn,Fe, Cu, As, and Se, and those of hair Se to Fe, Cu, and As, those of hair Fe to Mn, Cu, and As, those of hair Cu to Zn and As, and that between Zn and As were bigger than 0.739(all P ＜ 0.05). The correlation coefficient of urinary F to Se in patient group(0.762) was significantly different from that in control group( - 0.469, u = 2.079,P ＜ 0.05). Conclusions The burden of F and Al of osteomalacia malformation children in endemic fluorosis area of Shuicheng county is too high. The contents of multi-elements in urine and hairs and their correlation are coincident with high levels of Al and F and they cause network increase of multi-element content changes and their correlation. According to bone X-ray features combining with the living environment, the diagnosis of endemic Al-F fluorosis can be made. The biological significance of reducing urinary and hair Se levels and the correlations of F and Al need to be further studied.