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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.
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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.
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Objective To determine the effects of fluoride on osteoclasts's quantity and bone resorption function in vitro and 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. The osteoclasts were inoculated in 96-well culture plate and ivory slice, BMSCs were inoculated in 6- well culture plate, respectively, medium were changed after 2 hours incubation. They were divided into control group, low-dose fluoride, medium-dose fluoride and high-dose fluoride groups, the doses of sodium fluoride were 0,2.5 × 10-5,5.0 × 10-5,10.0 × 10-5 mol/L, respectively. Tartrate-resistant acid phosphatase(TRAP) staining positive cells were counted under light microscope after TRAP staining on the 2nd and the 5th day and the pit formed in ivory slices were measured by histomorphometry after staining with toludine blue. The expression of receptor activator of NK-κβ ligand(RANKL) and osteoprotegerin(OPC) was detected by real-time fluorescence quantitative (337.5 ± 70.5), (447.5 ± 43.4), (472.9 ± 34.8), (475.3 ± 24.3)/well in the control group, the low-dose, mediumdose and high-dose fluoride groups, respectively. The differences were statistically significant between these groups and the control group (all P < 0.05). After in vitro culture for 5 days, the numbers of osteoclasts were (92.5 ± 22.1), (123.0 ± 26.4), (135.5 ± 22.2), (136.9 ± 23.0) per well in the control group, the low-dose, medium-dose and high-dose fluoride groups, respectively. The differences were statistically significant between these groups and the (0.088 ± 0.030), (0.100 ± 0.018), (0.152 ± 0.015), (0.242 ± 0.031 )mm2 per piece in the control group, the lowdose, medium-dose and high-dose fluoride groups, respectively. The values of medium-dose and high-dose fluoride BMSCs in the control group, the low-dose, medium-dose and high-dose fluoride groups were 100.00 ± 56.02, 144.95 ± 97.21,223.25 ± 184.48,193.98 ± 137.93, respectively. The values of medium-dose and high-dose fluoride groups were significantly higher than that of control group (all P < 0.05). Conclusions Fluoride can cause increase in the number of osteoclasts in vitro and promote their cell differentiation and bone resorption activity, which may be related to increased expression ratio of RANKL/OPG mRNA in BMSCs.
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<p><b>OBJECTIVE</b>To observe the effects of two main isoflavones, daidzein and genistein on the bone-nodule formation in rat calvaria osteoblasts in vitro.</p><p><b>METHODS</b>Osteoblasts obtained from newborn Sprague-dawley rat calvaria were cultured for several generations. The second generation cells were cultured in Minimum Essential Medium supplemented with ascorbic acid and Na-beta-glycerophosphate for several days, in the presence of daidzein and genistein, with or without the estrogen receptor antagonist ICI 182780. Number of nodules was counted at the end of the incubation period (day 20) by staining with Alizarin Red S calcium stain. The release of osteocalcin, as a marker of osteoblast activity, was also determined on day 7 and day 12 during the incubation period.</p><p><b>RESULTS</b>Compared with the control, the numbers of nodules were both increased by incubation with daidzein and genistein. 17 beta-estradiol was used as a positive control and proved to be a more effective inducer of the increase in bone-nodules formation that daidzein and genistein. The release of osteocalcin into culture media was also increased in the presence of daidzein and genistein, as well as 17 beta-estradiol on day 7 and day 12 (day 12 were higher). The estrogen receptor antagonist ICI 182780 completely blocked the genistein- and 17 beta-estradiol-induced increase of nodule numbers and osteocalcin release in osteoblasts. However, the effects induced by daidzein could not be inhibited by ICI 182780.</p><p><b>CONCLUSION</b>These findings suggest that geinistein can stimulate bone-nodule formation and increase the release of osteocalcin in rat osteoblasts. The effects, like those induced by 17 beta-estradiol, are mediated by the estrogen receptor dependent pathway. Daidzein also can stimulate bone-nodule formation and increase the release of osteocalcin in rat osteoblasts, but it is not, at least not merely, mediated by the estrogen receptor dependent pathway.</p>
Subject(s)
Animals , Rats , Cells, Cultured , Genistein , Pharmacology , Isoflavones , Pharmacology , Osteoblasts , Cell Biology , Metabolism , Osteocalcin , Osteogenesis , Rats, Sprague-Dawley , Skull , Cell Biology , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To investigate the therapeutic effect of recombinant human parathyroid hormone(1-34) [rhPTH(1-34)] on osteoporosis of ovariectomized rats.</p><p><b>METHODS</b>The model of osteoporosis was formed after 3 months of ovariectomy with 6-month age of 80 rats. Another 20 rats was control of sham operation. rhPTH(1-34) was subcutaneously injected once daily with 5, 10, 20, 40 micrograms/kg for 3 months. There were 10 rats in each group. The control of therapy included Salmon Calcitonin to 10 rats and Alendronate sodium to 10 rats. The bone weight of dry and ash, bone mineral density, bone biomechanical property, trabecular area, bone mineral deposition and serum alkaline phosphatase, Ca, P and urinary Pyridinoline/creatin (Pyd/Cr) were measured after the end of therapy.</p><p><b>RESULTS</b>When administered to animals as a single subcutaneous injection once daily, rhPTH(1-34) increased obviously bone mass, bone biomechanical property and trabecular area, as well as bone deposition compared with the animals of control group. The bone architecture was ultimately improved by rhPTH(1-34) therapy.</p><p><b>CONCLUSIONS</b>Rats of ovariectomized-induced osteoporosis possess obvious effect of treatment with low dose of rhPTH(1-34) administered once daily.</p>