ABSTRACT
Objective To observe the effects of recombinant human parathyroid hormone 1 to 34(referred to as hPTH) on the expression level of alkaline phosphatase(ALP) and bone gla protein(BCP) in human osteosarcoma cell line SaOS-2(referred to as SaOS-2 cells). Methods SaOS-2 cells were subcultured and treated with 1, 10 and 100 nmol/L hPTH for 12, 24 and 48 h. Total cellular RNA was extracted, cDNA was synthesized by reverse doses of hPTH, different duration of action, and their interaction on the expression level of ALP mRNA of SaOS-2 cells was significantly different(F = 29.32, 2.92, 7.64, all P < 0.05). The expression level of ALP mRNA(0.78 ± 0.43, 0.71 ± 0.05, 0.75 ± 0.19, 0.76 ± 0.14) of SaOS-2 cells after treatment with 0, 1, 10 and 100 nmol/L hPTH for 48 h was lower than those of treated for 12 h(1.01 ± 0.16, 1.37 ± 0.38, 1.49 ± 0.16, 2.52 ± 0.70, all P< 0.05) and 24 h (1.80 ± 0.47, 1.30 ± 0.36, 1.27 ± 0.17, 1.17 ± 0.11, all P< 0.05). The expression level of ALP mRNA of SaOS-2 cells after treatment with 100 nmol/L hPTH for 12 hours was higher than that of the control(P < 0.05); the expression level of ALP mRNA of SaOS-2 cells after treatment with 1, 10 and 100 nmol/L hPTH for 24 h interaction on the expression level of BGP mRNA of SaOS-2 were significantly different (F = 8.26, 10.33, 5.51, all P< 0.05). The expression level of BGP mRNA(1.17 ± 0.28, 0.98 ± 0.08, 0.92 ± 0.17 and 0.84 ± 0.59) of SaOS2 cells after treatment with 0, 1, 10 and 100 nmol/L hPTH for 48 h was lower than those of treated for 12 h( 1.01 ± 0.14, 1.21 ± 0.18, 1.34 ± 0.30, 1.68 ± 0.62, all P< 0.05), and 24 h(1.71 ± 0.35, 1.41 ± 0.47, 1.28 ± 0.31 and 1.01 ± 0.18, all P < 0.05). The expression level of BGP mRNA of SaOS-2 cells after treatment with 100 nmol/L hPTH for 12 h was higher than that of those groups treated with 0 and 1 nmol/L hPTH(all P< 0.05). The expression level of BGP mRNA of SaOS-2 cells after treatment with 10 and 100 nmol/L hPTH for 24 h and 48 h was lower than those of the control(all P < 0.05). The expression level of BGP mRNA of SaOS-2 cells after treatment with 100 nmol/L hPTH for 24 hours was lower than that the group treated with 1 nmol/L hPTH(P < 0.05). Conclusions In vitro, hPTH significantly enhances osteogenic activities of human osteoblast in a short time, however, with prolonged stimulation time, osteogenic activity can show a downward trend.
ABSTRACT
Objective To investigate the effect of recombinant human bone morphogenetic protein 2 (rhBMP-2) on the osteogenic activities of human osteosarcoma cell line SaOS-2. Methods SaOS-2 cells were exposed to rhBMP-2 for 12,24,48 h at 0(control) ,2,20,200 μg/L, respectively. The mRNA expression of alkaline phosphatase(ALP) and bone gla(BCP) were detected by real time polymerase chain reaction. Results The mRNA expression of ALP and BGP of SaOS-2 cells increased gradually with rhBMP-2. The mRNA expression of ALP of the 20 μg/L group exposed for 48 h(1.60 ± 0.64), and the 200 μg/L group exposed for 12,48 h(1.70 ± 0.41, 1.80±0.19) were significantly higher than those of control (12 h: 0.80±0.25, 48 h: 0.74±0.21, allP<0.05). The mRNA expression of BGP of the 2 μg/L group exposed for 24 h(1.67 ± 0.33), the 20 μg/L group exposed for 12,24 h(2.42 ± 0.13,1.82 ± 0.14) and the 200 μg/L group exposed for 12,24 h(1.46 ± 0.11,1.24 ± 0.07) were significantly higher than those of control( 12 h: 1.01 ± 0.14, 24 h: 0.84 ± 0.12, all P< 0.05). Conclusions rhBMP-2 can promote the mRNA expression of ALP and BGP of SaOS-2 cells. They have a dose-response relationship, but represent a different dose-response effect.
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Objective To study the effect of fluoride on bone metabolism in rats, and to understand the mechanism of pathogenesis of skeletal fluorosis. Methods A total of 80 Wistar rats were randomly divided into 4 groups that included control group (distilled water), low-dose group(NaF, 50 mg/L), medium-dose group (NaF,100 mg/L) and high-dose group(NaF, 150 mg/L), respectively. After being bred for 12 weeks, the rats were put to death (etherization). Incidence of dental fluorosis was estimated, and serum was collected. Radioimmunoassay was employed to detect the levels of osteocalcin (BGP), parathyroid hormone (PTH) and calcitonin (CT), respectively.Colorimetry method was employed to determine the levels of alkaline phosphatase (ALP) and acid phosphatase (ACP). Results Incidence of dental fluorosis between the four groups was significantly different statistically(x2 =82.81 ,P ＜ 0.01 ). The incidence was significantly different(x2 = 22.67, 40.00, 40.00, all P＜ 0.01 ) between low-dose ( 80%, 16/20), medium-dose ( 100%, 20/20), high-dose groups ( 100%, 20/20) and control group (0,0/20),respectively. Serum levels of BGP, PTH, CT were significantly different between the groups(F = 38.614, 20.778,3.023, P ＜ 0.01 or ＜ 0.05). There was no significant difference between the four.groups of ALP and ACP in serum (F = 0.609,2.895, all P ＞ 0.05 ). Serum BGP in low-dose, medium-dose and high-dose groups[ ( 19.60 ± 12.79),(33.41 ± 10.81 ), (39.46 ± 9.51 )mg/L, respectively] was significantly higher than that of the control group[ (7.35 ± 3.22)mg/L, all P ＜ 0.01 ]. Serum PTH in low-dose, medium-dose and high-dose groups[ (72.27 ± 25.38), (67.80 ± 12.01), (106.52 ± 36.37)pmol/L] was significantly higher than that of the control group[(47.08 ± 9.22)pmol/L,all P ＜ 0.01 ]. Serum PTH of the high-dose group was significantly higher than that of the low-dose and the mediumdose groups(all P ＜ 0.01 ). Serum CT in medium-dose and high-dose groups[ ( 13.39 ± 2.07), ( 15.05 ± 4.77)pmol/L ] was significantly lower than that of the control group[ (26.06 ± 28.31 ) pmol/L, all P ＜ 0.05 ] and also significantly lower than that of the low-dose group [ (24.49 ± 14. 10) pmol/L, all P ＜ 0.05 ]. Conclusions Fluoride affects bone metabolism in rats, BGP, PTH and CT play a key role in the pathogenesis of skeletal fluorosis.
ABSTRACT
Objective To observe the influence of fluoride and aluminum on the expression of matrix metalloproteinase-13(MMP-13) in rat articular chondrocytes. Methods Original generation chondrocytes of rats was cultured and divided into fluoride group, aluminum group, fluoride plus aluminum group and control group. NaF and A1C13 at concentrations of 1 mmol/L and 2 mmol/L were administered to intoxicate the cells for 24, 48, 72 h respectively. Cells were extracted to undergo reverse transcription the polymerase chain reaction(RT-PCR) at different times to observe mRNA expression of MMP-13, and protein expression was detected by Western-blot. Results In 24 h, the content of MMP-13 mRNA in fluoride group(0.830±0.043), aluminum group(1.279±0.060) and fluoride plus aluminum group(0.983±0.028) was higher than that in the control group(0.707±0.026, P<0.05), and relative expression of MMP-13 mRNA in aluminum group was the highest. In 48 h, the content of MMP-13 mRNA in fluoride group (0.964±0.180), aluminum group (1.333±0.105) and fluoride plus aluminum group (0.915±0.137) was higher than that in the control group(0.660±0.055, P<0.05), and the relative expression in aluminum group was the highest. In 72 h, the content of MMP-13 mRNA in fluoride group(0.866±0.115), aluminum group(0.846±0.089) and fluoride plus aluminum group(0.967±0.196) had no statistical significance(P>0.05) compared with the control group(0.809±0.179). In 24 h, the content of MMP-13 protein in fluoride group(1.050±0.084), aluminum group(1.010±0.113) and fluoride plus aluminum group(0.977±0.202) had no statistical significance(P>0.05) compared with the control group(0.860±0.038). In 48 h, the content of MMP-13 protein in fluoride group(0.671±0.020), aluminum group(1.134±0.094) and fluoride plus aluminum group (0.923±0.087) was higher than that in the control group (0.647±0.025, P<0.05), but no significant difference being observed between groups (P>0.05). In 72 h, the content of MMP-13 protein in fluoride group(0.672±0.022), aluminum group(1.088±0.072) and fluoride plus aluminum group(0.772±0.030) was higher than that in the control group(0.577±0.026, P<0.05). It was the highest in the aluminum group, the intra-group difference had statistical significance(P<0.05). Conclusions Fluoride and aluminum damage chondrocytes to some extent, toxicity of aluminum itself is greater than fluoride and fluoride plus aluminum. Abnormal expression of MMP-13 can be observed in the chondrocyte damage process induced by fluoride and aluminum.