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Qiang Niu,
Hongliang Liu,
Zhizhong Guan,
Qiang Zeng,
Shuxia Guo,
Ping He, Lijuan Guo,
Ping Gao,
Bayi Xu,
Zhixia Xu,
Tao Xia,
Aiguo Wang
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ABSTRACT: To investigate the effects of sodium fluoride (NaF) on apoptosis, c-Fos mRNA and protein expression levels, and methylation status as well as Dnmt1, Dnmt3a, and Dnmt3b mRNA expression levels in human embryo hepatocyte (L-02) which were exposed to different concentrations of NaF (0, 20, 40, and 80 mg/l) for 24 h in vitro. Results showed that the percentage of apoptosis and c-Fos mRNA and protein expression levels in 40 and 80 mg/l NaF-treated groups were higher than those in the control group (P < 0.05). Further, Dnmt1 mRNA expression level was significantly decreased in the 80 mg/l NaF-treated groups compared to the control group (P < 0.05); Dnmt3a and Dnmt3b mRNA expression levels were significantly decreased in 40 and 80 mg/l NaF-treated groups compared to the control group (P < 0.05). c-Fos methylation levels, according to the bisulfite sequencing results, were decreased in 20, 40, and 80 mg/l NaF-treated groups against the control group. These results suggest that NaF could induce apoptosis and upregulate mRNA and protein expression level of c-Fos as well as decrease mRNA expression levels of Dnmt1, Dnmt3a, and Dnmt3b in L-02 cells. The decrease in c-Fos methylation levels might be involved in the early phase of apoptosis induced by NaF in L-02 cells.
Biological trace element research 04/2012; 149(1):102-9. · 1.92 Impact Factor
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ABSTRACT: The mechanisms underlying the neurotoxicology of endemic fluorosis still remain obscure. To explore lactate dehydrogenase (LDH) leakage, intracellular Ca(2+) concentration ([Ca(2+) ](i) ) and reactive oxygen species (ROS) production induced by fluoride, human neuroblastoma (SH-SY5Y) cells were incubated with sodium fluoride (NaF, 20, 40, 80 mg/L) for 24 h, with 40 mg/L NaF for 3, 6, 12, 18, 24 h, and N-acetyl-L-cysteine (NAC), ethyleneglycol-bis-(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA), 1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra(acetoxymethyl) ester (BAPTA-AM) alone or combined with fluoride (40 mg/L) respectively for 12 h in vitro. The results showed that the LDH levels in the 40 and 80 mg/L fluoride-treated groups were significantly higher than that of the control group (in the test level of 0.05, the difference were statistical significance). [Ca(2+) ](i) and ROS reached a peak at 3 h and 12 h respectively after exposure to 40 mg/L fluoride. Fluoride coincubated with NAC (antioxidant) dramatically decreased ROS and LDH levels compared with the fluoride only group (in the test level of 0.05, the difference were statistical significance). However, fluoride-induced increase in [Ca(2+) ](i) was not affected by NAC. BAPTA-AM (intracellular calcium chelator) markedly lowered fluoride-induced increase of [Ca(2+) ](i) , ROS and LDH levels while EGTA (extracellular calcium chelator) have no effects on them. These results indicate that fluoride-related Ca(2+) release from the site of intracellular calcium storage causes the elevation of ROS contributing to the cytotoxicity in SH-SY5Y cells. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Environmental Toxicology 07/2011; · 2.41 Impact Factor
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ABSTRACT: The mechanisms underlying the neurotoxicology of endemic fluorosis still remain obscure. To explore lactate dehydrogenase (LDH) leakage, intracellular Ca2+ concentration ([Ca2+]i) and reactive oxygen species (ROS) production induced by fluoride, human neuroblastoma (SH-SY5Y) cells were incubated with sodium fluoride (NaF, 20, 40, 80 mg/L) for 24 h, with 40 mg/L NaF for 3, 6, 12, 18, 24 h, and N-acetyl-L-cysteine (NAC), ethyleneglycol-bis-(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA), 1,2-bis(O-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid tetra(acetoxymethyl) ester (BAPTA-AM) alone or combined with fluoride (40 mg/L) respectively for 12 h in vitro. The results showed that the LDH levels in the 40 and 80 mg/L fluoride-treated groups were significantly higher than that of the control group (in the test level of 0.05, the difference were statistical significance). [Ca2+]i and ROS reached a peak at 3 h and 12 h respectively after exposure to 40 mg/L fluoride. Fluoride coincubated with NAC (antioxidant) dramatically decreased ROS and LDH levels compared with the fluoride only group (in the test level of 0.05, the difference were statistical significance). However, fluoride-induced increase in [Ca2+]i was not affected by NAC. BAPTA-AM (intracellular calcium chelator) markedly lowered fluoride-induced increase of [Ca2+]i, ROS and LDH levels while EGTA (extracellular calcium chelator) have no effects on them. These results indicate that fluoride-related Ca2+ release from the site of intracellular calcium storage causes the elevation of ROS contributing to the cytotoxicity in SH-SY5Y cells. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Environmental Toxicology 07/2011; · 2.41 Impact Factor
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ABSTRACT: Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are widespread environmental contaminants. There are potential interactive effects between PBDEs and PCBs, as these compounds share similar structures. The developmental neurotoxicity of 2, 2', 4, 4'-tetrabromodiphenyl ether (PBDE-47) and the interaction of PBDE-47 with 2, 2', 4, 4', 5, 5'-hexachlorobipheny (PCB153) were investigated herein, as the dominant congener forms of PBDEs and PCBs, respectively. SD rats were exposed to a single oral dose of PBDE-47 (1, 5, and 10 μg/g) and/or PCB153 (5 μg/g) on post-natal day (PND) 10. Concentrations of PBDE-47, triiodothyronine (T(3)), thyroxine (T(4)), and thyroid-stimulating hormone (TSH) in serum; organ-to-body weight ratios; as well as long-term learning and memory were measured in 2-month-old rats. The present study found that some doses of PBDE-47 decreased the organ-to-body weight ratios of the thyroid and uterus, decreased the concentration of T(4) in serum, and increased the organ-to-body weight ratio of the ovaries (p < 0.05). PCB153 could increase the action of PBDE-47 during combined exposure, but this interaction was not found between PBDE-47 and PCB153. In a Morris water maze experiment, the latency periods were significantly prolonged and time ratios were obviously depressed in all PBDE-47-treated groups compared to the control (p < 0.05); furthermore, significant interactions between PBDE-47 and PCB153 were observed (p < 0.05). In conclusion, PBDE-47 may depress thyroid development as well as the long-term learning and memory capabilities in adult rats exposed to PBDE-47 on PND 10. PCB153 can interact with PBDE-47, resulting in an increase in developmental neurotoxicity.
Toxicology and Industrial Health 04/2011; 27(3):279-88. · 1.42 Impact Factor
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ABSTRACT: The mechanisms underlying fluoride-induced apoptosis in neurons still remain unknown. To investigate apoptosis, caspase-3 activity, and mRNA expression of Fas, Fas-L, and caspases (-3 and -8) induced by fluoride, human neuroblastoma (SH-SY5Y) cells were incubated with 0, 20, 40, and 80 mg/L sodium fluoride (NaF) for 24 h in vitro. The data show that cell viability in the 40 and 80 mg/L fluoride groups were significantly lower than that of the control group. The percentages of apoptosis in the 40 and 80 mg/L fluoride groups were markedly higher than those in the control group, and they increased with the increase in fluoride concentration. The activity of caspase-3 and mRNA expression levels for Fas, Fas-L, and caspases (-3 and -8) in the 40 and 80 mg/L fluoride groups were significantly higher than those in the control group. An agonistic anti-Fas monoclonal antibody (CH-11) significantly augmented apoptosis induction by fluoride, showing a synergistic effect, while a Fas-blocking antibody (ZB4) partly inhibited fluoride-induced apoptosis of SH-SY5Y cells. The results indicate that fluoride exposure could induce apoptosis in SH-SY5Y cells, and the Fas/Fas-L signaling pathway may play an important role in the process.
Environmental Toxicology 10/2009; 26(1):86-92. · 2.41 Impact Factor
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ABSTRACT: To explore the effects of PCB153 (2,2,4,4,5,5-hexachlorobiphenyl) on oxidative stress and 8-OHdG (8-hydroxy-2'-deoxyguanosine) content induced by PBDE-47 (2,2,4,4-tetrabromodiphenyl ether) in SH-SY5Y cells.
SH-SY5Y cells were incubated with different concentrations of 1, 5, 10 micromol/L PBDE-47 or/and 5 micromol/L PCB153 and antioxidant N-acetyl cysteine (NAC 100 micromol/L) for 24h in vitro, ROS (reactive oxygen species) level and 8-OHdG were measured by using DCFH-DA fluorescent marking method and the skill of high performance liquid chromatogram-electrochemistry (HPLC-EC), respectively.
As for ROS formation, there was no significant difference in PBDE-47 groups alone compared to the control group and their corresponding combined groups, respectively (P > 0.05). ROS formation were significantly increased in 5 and 10 micromol/L combined groups compared to the control group and their corresponding concentrations of PBDE-47 groups or PCB153 group, respectively (P < 0.05). 8-OHdG levels were significantly increased in 10 micromol/L PBDE-47, 5 micromol/L PBDE-47 + 5 micromol/L PCB153, and 10 micromol/L PBDE-47 + 5 micromol/L PCB153 groups compared with the control (P < 0.05). 8-OHdG level was dramatically increased in 10 micromol/L PBDE-47 + 5 micromol/L PCB153 groups compared to their corresponding doses of PBDE-47 groups or PCB153 group (P < 0.05). The groups coincubation with N-acetylcysteine caused a decrease in cellular ROS level and ameliorated PBDE-47-mediated oxidative DNA damage effects. Positive relationship was observed between ROS level and 8-OHdG contents (r = 0.895, P < 0.01).
These results provide evidence of a direct or indirect relationship between PBDE-47 and oxidative DNA damage. Furthermore, PBDE-47 combined with PCB153 may increase the effects on oxidative DNA damage in SH-SY5Y cells in vitro, oxidative stress may responsible for DNA damage induced by PBDE-47.
Wei sheng yan jiu = Journal of hygiene research 09/2009; 38(5):513-5.
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ABSTRACT: We studied the relationship between 2,2,4,4-tetrabromodiphenyl ether (PBDE-47) and oxidative DNA damage as well as the mode of interaction between PBDE-47 and 2,2,4,4,5,5-hexachlorobiphenyl (PCB153) by incubating SH-SY5Y cells in four doses of PBDE-47 (0, 1, 5, 10 microM) and/or 5 microM PCB153 and 100 microM NAC (N-acetylcysteine) for 24 h. Results showed that reactive oxygen species (ROS) production in the 5 microM PBDE-47 + PCB153 and 10 microM PBDE-47 + PCB153 groups were significantly higher than that of the control group (p < 0.05). DNA strand breakage and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were significantly increased in the 10 microM PBDE-47, 5 microM PBDE-47 + PCB153, and 10 microM PBDE-47 + PCB153 groups compared with the control (p < 0.05). Furthermore, ROS formation and DNA strand breakage were dramatically increased in the 5 microM PBDE-47 + PCB153 and 10 microM PBDE-47 + PCB153 groups compared with the corresponding PBDE-47 only group and the PCB153 group (p< 0.05). The level of 8-OHdG was significantly increased in the 10 microM PBDE-47 + PCB153 group compared with the corresponding PBDE-47 only group and the PCB153 group (p < 0.05). The PBDE-47 group coincubated with NAC decreased the ROS level and ameliorated PBDE-47-mediated DNA damage. The mRNA expression levels of X-ray repair cross-complementing gene 1 (Xrcc1) were significantly decreased in the 10 microM PBDE-47, 5 microM PBDE-47 + PCB153, and 10 microM PBDE-47 + PCB153 groups, whereas X-ray repair cross-complementing gene 3 (Xrcc3) were significantly increased in the 10 microM PBDE-47 and 10 microM PBDE-47 + PCB153 groups compared with the control (p < 0.05). The PBDE-47 groups coincubated with NAC, however, considerably increased Xrcc1 while decreasing Xrcc3 mRNA expression (p < 0.05). These results indicate that PBDE-47 induced oxidative DNA damage and that PBDE-47 combined with PCB153 may increase such effects in SH-SY5Y cells in vitro. Furthermore, our results suggest that oxidative stress is responsible for DNA damage induced by PBDE-47.
Toxicological Sciences 10/2008; 107(1):165-70. · 4.65 Impact Factor
