Decabromodiphenyl ether （decaBDE）,as a flame retardant,is widely produced and used.To study the thyroid disruption by technical decaBDE at low concentrations,Xenopus laevis tadpoles were exposed to technical decaBDE...Decabromodiphenyl ether （decaBDE）,as a flame retardant,is widely produced and used.To study the thyroid disruption by technical decaBDE at low concentrations,Xenopus laevis tadpoles were exposed to technical decaBDE mixture DE-83R （1-1000 ng/L） in water from stage 46/47 （free swimming larvae,system of Nieuwkoop and Faber） to stage 62.DE-83R at concentration of 1000 ng/L significantly delayed the time to metamorphosis （presented by forelimb emergence,FLE）.Histological examination showed that DE83R at all tested concentrations caused histological alterations-multilayer follicular epithelial cell and markedly increased follicle size accompanied by partial colloid depletion and increase in the peripheral colloid vacuolation,in thyroid glands.All tested concentrations of DE-83R also induced a down-regulation of thyroid receptor mRNA expression.These results demonstrated that technical decaBDE disrupted the thyroid system in X.laevis tadpoles.Analysis of polybrominated diphenyl ethers （PBDEs） （sum of 39 congeners） in X.laevis indicated that mean concentrations of total PBDEs in X.laevis exposed to 1,10,100,1000 ng/L were 11.0,128.1,412.1,1400.2 ng/g wet weight,respectively.Considering that PBDEs burden of X.laevis tadpoles was close to PBDEs levels in amphibians as reported in previous studies,our study has raised new concerns for thyroid disruption in amphibians of technical decaBDE at environmentally relevant concentrations.展开更多
BACKGROUND Decabromodiphenyl ether(BDE-209)is the most commonly used brominated flame retardant.Recently,BDE-209 has been suspected of being an environmental risk factor for metabolic diseases such as obesity,insulin ...BACKGROUND Decabromodiphenyl ether(BDE-209)is the most commonly used brominated flame retardant.Recently,BDE-209 has been suspected of being an environmental risk factor for metabolic diseases such as obesity,insulin resistance(IR),type 2 diabetes mellitus,and hypertension.AIM To investigate the effects of BDE-209 on IR and glucose and lipid metabolism in C57BL/6 mice.METHODS Adult male C57BL/6 mice were randomly divided into high,medium-high,medium,medium-low,and low dose BDE-209 groups,and a control group(n=6 per group),which received 1000,800,600,450,300,and 0 mg/kg BDE-209,respectively.After BDE-209 exposure for 60 d,the mice were fasted overnight,and then sacrificed to obtain tissues.An automatic biochemical analyzer was used to detect serum triglyceride(TG),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),and high density lipoprotein cholesterol(HDL-C);enzymelinked immunosorbent assay kits were used to detect fasting serum insulin(FINS),leptin(LEP),and adiponectin(Adp)levels;a blood glucose meter was used to detect fasting blood glucose(FBG).Morphological changes of the liver were observed by hematoxylin and eosin staining.Real-time quantitative polymerase chain reaction and Western blot were used to determine the messenger ribonucleic acid(mRNA)and protein levels,respectively,of LEP,Adp,and peroxisome proliferators activated receptor-γ(PPARγ)in mouse liver and adipose tissues.RESULTS There was a statistically significant difference in the weight of mice in each group after 45 and 60 d of exposure(P<0.05).After 60 d of exposure,the weight of liver and adipose tissues in the exposure groups were greater than that of the control group(P<0.05).The liver tissue structure was disordered and the liver tissues were accompanied by local inflammatory cell infiltration in the high,mediumhigh,and medium dose BDE-209 groups.The levels of FINS,insulin sensitivity index,Adp,and HDL-C were decreased in the BDE-209 group compared with the control group,as were the mRNA and protein levels of Adp in liver and adipose tissues(P<0.05).Serum level of FBG and LEP were higher in the BDE-209 group than in controls.TC,TG,and LDL-C levels as well as the mRNA and protein expression of LEP and PPARγin liver and adipose tissues were higher than those in the control group(P<0.05).Homeostatic assessment model of IR was higher in the medium and medium-low dose BDE-209 groups(P<0.05).CONCLUSION BDE-209 increases the body weight,fat and liver tissue weight,TC,TG,and LDLC,reduces HDL-C,and causes IR in mice,which may be related to activating the PPARγreceptor.展开更多
基金supported by the Knowledge Innovation Program of Chinese Academy of Sciences(No. KZCX2-YW-420-3,KZCX2-YW-Q-02-05)the National Natural Science Foundation of China (No.20437020,20677074)
文摘Decabromodiphenyl ether （decaBDE）,as a flame retardant,is widely produced and used.To study the thyroid disruption by technical decaBDE at low concentrations,Xenopus laevis tadpoles were exposed to technical decaBDE mixture DE-83R （1-1000 ng/L） in water from stage 46/47 （free swimming larvae,system of Nieuwkoop and Faber） to stage 62.DE-83R at concentration of 1000 ng/L significantly delayed the time to metamorphosis （presented by forelimb emergence,FLE）.Histological examination showed that DE83R at all tested concentrations caused histological alterations-multilayer follicular epithelial cell and markedly increased follicle size accompanied by partial colloid depletion and increase in the peripheral colloid vacuolation,in thyroid glands.All tested concentrations of DE-83R also induced a down-regulation of thyroid receptor mRNA expression.These results demonstrated that technical decaBDE disrupted the thyroid system in X.laevis tadpoles.Analysis of polybrominated diphenyl ethers （PBDEs） （sum of 39 congeners） in X.laevis indicated that mean concentrations of total PBDEs in X.laevis exposed to 1,10,100,1000 ng/L were 11.0,128.1,412.1,1400.2 ng/g wet weight,respectively.Considering that PBDEs burden of X.laevis tadpoles was close to PBDEs levels in amphibians as reported in previous studies,our study has raised new concerns for thyroid disruption in amphibians of technical decaBDE at environmentally relevant concentrations.
基金Supported by National Natural Science Foundation of China,No.81760596Natural Science Foundation of Xinjiang Uygur Autonomous Region,No.2019D01C209.
文摘BACKGROUND Decabromodiphenyl ether(BDE-209)is the most commonly used brominated flame retardant.Recently,BDE-209 has been suspected of being an environmental risk factor for metabolic diseases such as obesity,insulin resistance(IR),type 2 diabetes mellitus,and hypertension.AIM To investigate the effects of BDE-209 on IR and glucose and lipid metabolism in C57BL/6 mice.METHODS Adult male C57BL/6 mice were randomly divided into high,medium-high,medium,medium-low,and low dose BDE-209 groups,and a control group(n=6 per group),which received 1000,800,600,450,300,and 0 mg/kg BDE-209,respectively.After BDE-209 exposure for 60 d,the mice were fasted overnight,and then sacrificed to obtain tissues.An automatic biochemical analyzer was used to detect serum triglyceride(TG),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),and high density lipoprotein cholesterol(HDL-C);enzymelinked immunosorbent assay kits were used to detect fasting serum insulin(FINS),leptin(LEP),and adiponectin(Adp)levels;a blood glucose meter was used to detect fasting blood glucose(FBG).Morphological changes of the liver were observed by hematoxylin and eosin staining.Real-time quantitative polymerase chain reaction and Western blot were used to determine the messenger ribonucleic acid(mRNA)and protein levels,respectively,of LEP,Adp,and peroxisome proliferators activated receptor-γ(PPARγ)in mouse liver and adipose tissues.RESULTS There was a statistically significant difference in the weight of mice in each group after 45 and 60 d of exposure(P<0.05).After 60 d of exposure,the weight of liver and adipose tissues in the exposure groups were greater than that of the control group(P<0.05).The liver tissue structure was disordered and the liver tissues were accompanied by local inflammatory cell infiltration in the high,mediumhigh,and medium dose BDE-209 groups.The levels of FINS,insulin sensitivity index,Adp,and HDL-C were decreased in the BDE-209 group compared with the control group,as were the mRNA and protein levels of Adp in liver and adipose tissues(P<0.05).Serum level of FBG and LEP were higher in the BDE-209 group than in controls.TC,TG,and LDL-C levels as well as the mRNA and protein expression of LEP and PPARγin liver and adipose tissues were higher than those in the control group(P<0.05).Homeostatic assessment model of IR was higher in the medium and medium-low dose BDE-209 groups(P<0.05).CONCLUSION BDE-209 increases the body weight,fat and liver tissue weight,TC,TG,and LDLC,reduces HDL-C,and causes IR in mice,which may be related to activating the PPARγreceptor.
