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Li YY, Shi ZY, Xiong YM, Chen XY, Lv L, Huang H, Liu W, Zhao J, Li XH, Qin ZF. Bioaccumulation and Male Reproductive Toxicity of the New Brominated Flame Retardant Tetrabromobisphenol A-Bis(2,3-dibromo-2-methylpropyl ether) in Comparison with Hexabromocyclododecane. Environ Sci Technol 2024; 58:4127-4136. [PMID: 38382014 DOI: 10.1021/acs.est.3c10560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Tetrabromobisphenol A-bis(2,3-dibromo-2-methylpropyl ether) (TBBPA-DBMPE) has come into use as an alternative to hexabromocyclododecane (HBCD), but it is unclear whether TBBPA-DBMPE has less hazard than HBCD. Here, we compared the bioaccumulation and male reproductive toxicity between TBBPA-DBMPE and HBCD in mice following long-term oral exposure after birth. We found that the concentrations of TBBPA-DBMPE in livers significantly increased with time, exhibiting a bioaccumulation potency not substantially different from HBCD. Lactational exposure to 1000 μg/kg/d TBBPA-DBMPE as well as 50 μg/kg/d HBCD inhibited testis development in suckling pups, and extended exposure up to adulthood resulted in significant molecular and cellular alterations in testes, with slighter effects of 50 μg/kg/d TBBPA-DBMPE. When exposure was extended to 8 month age, severe reproductive impairments including reduced sperm count, increased abnormal sperm, and subfertility occurred in all treated animals, although 50 μg/kg/d TBBPA-DBMPE exerted lower effects than 50 μg/kg/d HBCD. Altogether, all data led us to conclude that TBBPA-DBMPE exerted weaker male reproductive toxicity than HBCD at the same doses but exhibited bioaccumulation potential roughly equivalent to HBCD. Our study fills the data gap regarding the bioaccumulation and toxicity of TBBPA-DBMPE and raises concerns about its use as an alternative to HBCD.
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Affiliation(s)
- Yuan-Yuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Zhe-Yuan Shi
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Yi-Ming Xiong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Xuan-Yue Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Lin Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Honglin Huang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Wenbin Liu
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
- Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Jing Zhao
- Solid Waste and Chemicals Management Center, Ministry of Ecology and Environment, Beijing 100029, China
| | - Xing Hong Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Zhan-Fen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
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Chen XY, Li YY, Lv L, Xiong YM, Qin ZF. The brominated flame retardant tetrabromobisphenol A-bis(2,3-dibromo-2-methylpropyl ether) as well as hexabromocyclododecane lead to lipid disorders in mice. Environ Pollut 2024; 341:122895. [PMID: 37949162 DOI: 10.1016/j.envpol.2023.122895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/10/2023] [Accepted: 11/05/2023] [Indexed: 11/12/2023]
Abstract
The brominated flame retardant tetrabromobisphenol A-bis(2,3-dibromo-2-methylpropyl ether) (TBBPA-DBMPE) is a recommended substitute for hexabromocyclododecane (HBCD), a banned persistent organic pollutant, yet its potential toxicities remains largely unexplored. Here, we investigated the effects of a long-term exposure to TBBPA-DBMPE at nominal doses of 50 and 1000 μg/kg/d on lipid homeostasis in CD-1 mice, in comparison with 50 μg/kg/d HBCD as a positive control. Male pups received chemical treatments through maternal administration via drinking water from postnatal day 0-21, followed by direct administration through drinking water after weaning. On the 23rd week after treatment, the oral lipid tolerance test revealed that low-dose TBBPA-DBMPE as well as HBCD affected lipid tolerance, although the fasting serum triglyceride (TG) levels were not altered. When chemical treatment was extended to the 32nd week, TBBPA-DBMPE-treated animals displayed adipocyte hypertrophy in both white adipose tissue (eWAT) and brown adipose tissue (BAT) and hepatic steatosis, which was largely consistent with the effects of HBCD. These findings indicate that like HBCD, TBBPA-DBMPE led to increased lipid load in mice. Interestingly, we also observed intestinal histological changes, coupled with increased expression of lipid absorption-related genes in both HBCD and TBBPA-DBMPE treatments, suggesting increased lipid absorption. This was supported by in vitro findings that both HBCD and TBBPA-DBMPE promoted lipid accumulation in IEC-6 cells under the stress of oleic acid for 6 h, implying that altered lipid absorption by the intestine may partly contributed to increased lipid load in mice. Overall, the effects of 50 μg/kg/d TBBPA-DBMPE in terms of some parameters were comparable with 50 μg/kg/d HBCD, suggesting that TBBPA-DBMPE may not be an ideal substitute of HBCD.
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Affiliation(s)
- Xuan-Yue Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuan-Yuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lin Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yi-Ming Xiong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhan-Fen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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Li YY, Xiong YM, Chen XY, Sheng JY, Lv L, Li XH, Qin ZF. Extended exposure to tetrabromobisphenol A-bis(2,3-dibromopropyl ether) leads to subfertility in male mice at the late reproductive age. Arch Toxicol 2023; 97:2983-2995. [PMID: 37606655 DOI: 10.1007/s00204-023-03589-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 08/10/2023] [Indexed: 08/23/2023]
Abstract
Tetrabromobisphenol A-bis(2,3-dibromopropyl ether) (TBBPA-BDBPE), a commonly used brominated flame retardant as a decabromodiphenyl ether substitute, has been detected in various environmental compartments, but its health hazards remain largely unknown. Our recent study showed that low-dose exposure of male mice to TBBPA-BDBPE from postnatal day (PND) 0 to 56 caused remarkable damage to the microtubule skeleton in Sertoli cells and the blood-testis barrier (BTB) but exerted little effect on conventional reproductive endpoints in adulthood. To investigate whether TBBPA-BDBPE may cause severe reproductive impairments at late reproductive age, here, we extended exposure of historically administrated male mice to 8-month age and allowed them to mate with non-treated females for the evaluation of fertility, followed by a general examination for the reproductive system. As expected, we found that 8-month exposure to 50 μg/kg/d as well as 1000 μg/kg/d TBBPA-BDBPE caused severe damage to the reproductive system, including reduced sperm counts, increased sperm abnormality, histological alterations of testes. Moreover, microtubule damage and BTB-related impairment were still observed following 8-month exposure. Noticeably, high-dose TBBPA-BDBPE-treated mice had fewer offspring with a female-biased sex ratio. All results show that long-term exposure to TBBPA-BDBPE caused severe reproductive impairment, including poor fertility at late reproductive age. It is therefore concluded that slight testicular injuries in early life can contribute to reproductive impairment at late reproductive age, highlighting that alterations in certain non-conventional endpoints should be noticed as well as conventional endpoints in future reproductive toxicity studies.
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Affiliation(s)
- Yuan-Yuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Haidian District, No. 18, Shuangqing Road, Beijing, 100085, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yi-Ming Xiong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Haidian District, No. 18, Shuangqing Road, Beijing, 100085, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xuan-Yue Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Haidian District, No. 18, Shuangqing Road, Beijing, 100085, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jia-Yi Sheng
- The High School Affiliated to Renmin, University of China, Beijing, 100080, China
| | - Lin Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Haidian District, No. 18, Shuangqing Road, Beijing, 100085, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xing-Hong Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Haidian District, No. 18, Shuangqing Road, Beijing, 100085, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhan-Fen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Haidian District, No. 18, Shuangqing Road, Beijing, 100085, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Department of Life Sciences, Hengshui University, Hebei, 053000, China.
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Li HM, Zhang YC, Li YY, Zhu QQ, Li J, Xu HM, Xiong YM, Qin ZF. Low concentrations of benzophenone-type UV-filters impair testis development in the amphibian Xenopus laevis. Aquat Toxicol 2023; 254:106371. [PMID: 36529091 DOI: 10.1016/j.aquatox.2022.106371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/03/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Benzophenone-type UV filters (BPs) are ubiquitous contaminants in aquatic environments, possibly posing ecological risks to aquatic populations. So far, little is known about the potential adverse effects of BPs on amphibians. Given their potential estrogenic property, we investigated the detrimental effects of the commonly used BPs, BP-3, BP-2, and BP-1, on testis development in amphibians using Xenopus laevis as a model species. Following exposure to 10, 100, 1000 nM BP-3, BP-2, or BP-1 from stages 45/46 to 52, tadpoles presented morphological abnormal testes, characterized by reduced gonomere size and testis area, coupled with suppressed cell proliferation. Meanwhile, the downregulation of testis-biased gene expression and the upregulation of ovary-biased gene expression were observed in BPs-treated testes. Moreover, the estrogen receptor (ER) antagonist ICI 182780 significantly antagonized ovary-biased gene upregulation caused by BPs, suggesting that the effects of BPs on testis differentiation could be mediated by ER, at least partially. Of note, the effects of BPs were not concentration-dependent, but the lowest concentration generally exerted significant effects. Altogether, these observations indicate that the three BPs inhibited testis differentiation and exerted feminizing effects. Importantly, when BP-2 exposure was extended to two months post-metamorphosis, testes of froglets were generally less-developed, with relatively fewer spermatocytes, more spermatogonia, and poorly formed seminiferous tubules. Considering the fact that the lowest concentration (10 nM) of BPs in this study are detectable in aquatic environments, we conclude that BP-3, BP-2, and BP-1, even at environmentally relevant concentrations, can retard testis differentiation at pre-metamorphic stages and cause testis dysgenesis after metamorphosis in the amphibian X. laevis. Our findings suggest that ubiquitous BPs in aquatic environments could pose a potential risk to amphibians.
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Affiliation(s)
- Hong-Mei Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Ying-Chi Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Yuan-Yuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Qing-Qing Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Hai-Ming Xu
- Ningxia Medical University, Yinchuan, Ningxia 750004, China; Department of Occupational and Environmental Hygiene, School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Yi-Ming Xiong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhan-Fen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
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Xiong YM, Li YY, Lv L, Chen XY, Li XH, Qin ZF. Postnatal exposure to low-dose tetrabromobisphenol A increases the susceptibility of mammal testes to chemical-induced spermatogenic stress in adulthood. Environ Int 2023; 171:107683. [PMID: 36512917 DOI: 10.1016/j.envint.2022.107683] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/02/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
There is increasing data showing that some environmental chemicals can increase susceptibility to follow-up stress or injuries, possibly thereby contributing to certain clinical and subclinical diseases. Previous studies reported that tetrabromobisphenol A (TBBPA), one of the most used brominated flame retardants, exerted little male reproductive toxicity in terms of conventional endpoints but affected testis development and thereby caused testicular alterations at the molecular and cellular levels. Here, we aimed to reveal whether developmental exposure to TBBPA can increase testicular susceptibility to follow-up stress in adulthood. For this purpose, newborn mice were exposed to 50 or 500 μg/kg/d TBBPA for 56 days to confirm adverse effects on testes, followed by a single intraperitoneal injection of 3 mg/kg busulfan (BSF) to induce spermatogenic stress. Four weeks after BSF injection, TBBPA-treated mice exhibited severe pathological alterations, including reduced testis weight, damaged testicular histological structure, declined sperm count, apoptosis of spermatogenic cells, while no remarkable damage was observed in mice without historical exposure to TBBPA. These results demonstrate that historical exposure to TBBPA, either 50 or 500 µg/kg/d, increased the susceptibility of mouse testes to BSF-induced spermatogenic stress, resulting in severe adverse reproductive outcomes. Further analysis indicates that TBBPA-caused microtubule and microfilament damage, along with spermatogonia and spermatocyte reduction, could contributed to the increased susceptibility of testes, suggesting that these non-conventional reproductive lesions caused by chemicals should not be ignored. This is the first study to investigate the reproductive hazard of chemicals from the perspective of testicular susceptibility to stress, thereby opening a new avenue to identify environmental chemicals possibly contributing to male infertility and subfertility.
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Affiliation(s)
- Yi-Ming Xiong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan-Yuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Lin Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuan-Yue Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xing-Hong Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhan-Fen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
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Li HM, Li YY, Zhang YC, Li JB, Xu HM, Xiong YM, Qin ZF. Bisphenol B disrupts testis differentiation partly via the estrogen receptor-mediated pathway and subsequently causes testicular dysgenesis in Xenopus laevis. Ecotoxicol Environ Saf 2022; 236:113453. [PMID: 35390692 DOI: 10.1016/j.ecoenv.2022.113453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 03/09/2022] [Accepted: 03/22/2022] [Indexed: 06/14/2023]
Abstract
There is growing concern about adverse effects of bisphenol A alternatives including bisphenol B (BPB) due to their estrogenic activity. However, limited data are available concerning the influences of BPB on male reproductive development in vertebrates, especially in amphibians, which are believed to be susceptible to estrogenic chemicals. The present study investigated the effects of 10, 100 and 1000 nM BPB (2.42, 24.2 and 242 μg/L) on testis development in Xenopus laevis, a model amphibian species for studying gonadal feminization. We found that exposure to BPB from stages 45/46 to 52 resulted in down-regulation of testis-biased gene expression and up-regulation of ovary-biased gene and vitellogenin (vtgb1) expression in gonad-mesonephros complexes (GMCs) of tadpoles at stage 52, coupled with suppressed cell proliferation in testes and reduced gonadal metameres, resembling the effects of 17ß-estradiol. Moreover, an estrogen receptor (ER) antagonist ICI 182780 antagonized BPB-caused up-regulation of ovary-biased gene and vtgb1 expression to some degree, indicating that the effects of BPB on X. laevis testis differentiation could be partly mediated by ER. All observations demonstrate that early exposure to BPB inhibited testis differentiation and exerted certain feminizing effects during gonadal differentiation. When exposure was extended to post-metamorphosis, testes exhibited histological and morphological abnormalities including segmented, discontinuous and fragmented shapes, besides altered sex-dimorphic gene expression. Notably, most of BPB-caused alterations were not concentration-dependent, but the lowest concentration indeed exerted significant effects. Overall, our study for the first time reveals that low concentrations of BPB can disrupt testis differentiation partly due to its estrogenic activity and subsequently cause testicular dysgenesis after metamorphosis, highlighting its reproductive risk to amphibians and other vertebrates including humans. Our finding also implies that estrogenic chemicals-caused testis differentiation inhibition at tadpole stages could predict later testicular dysgenesis after metamorphosis, meaning a possibility of early detection of abnormal testis development caused by estrogenic chemicals.
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Affiliation(s)
- Hong-Mei Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Yuan-Yuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying-Chi Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Department of Occupational and Environmental Hygiene, School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Jin-Bo Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hai-Ming Xu
- Department of Occupational and Environmental Hygiene, School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Yi-Ming Xiong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhan-Fen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
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Du XA, Wang HM, Dai XX, Kou Y, Wu RP, Chen Q, Cao JL, Mo XY, Xiong YM. Role of selenoprotein S (SEPS1) -105G>A polymorphisms and PI3K/Akt signaling pathway in Kashin-Beck disease. Osteoarthritis Cartilage 2015; 23:210-6. [PMID: 25433273 DOI: 10.1016/j.joca.2014.11.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 11/07/2014] [Accepted: 11/14/2014] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate the relationship between SEPS1 polymorphism and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway in Kashin-Beck disease (KBD) and further explore the pathogenesis of KBD. METHODS Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect SEPS1 -105G>A polymorphism in 232 cases and 331 controls. The protein expressions of PI3K/Akt signaling molecules in whole blood and chondrocytes were detected by Western blot. RESULTS The frequencies of SEPS1 -105G>A genotype AA (21.1% vs 3.0%) and minor allele A (34.1% vs 16.0%) in KBD are significantly higher than those in controls (OR: 8.020, 95% confidence interval (95% CI) 6.341-10.290, P < 0.0001; OR: 2.470, 95% CI 2.001-4.463, P < 0.0001, respectively). SEPS1 AA genotype was an independent risk factor for KBD (adjusted OR: 9.345, 95% CI 4.254-20.529; P < 0.0001). The expression of Gβγ, PI3Kp110, pAkt and pGSK3β in KBD group were higher than that in control group (all P < 0.05). Gβγ, pAkt and pGSK3β protein expression of AA and GA increased than GG (all P < 0.05). Cell apoptosis was increasing and molecule expression of PI3K/Akt signaling pathway were up-regulated in the tert-Butyl hydroperoxide (tBHP)-injured group, the cell apoptosis and expression levels of PI3K/Akt in Na2SeO3 group were decreased. CONCLUSIONS The SEPS1 -105G>A is associated with an increased risk of KBD and influences the expression of PI3K/Akt signaling pathway in KBD patients. Apoptosis induced by tBHP in chondrocyte might be mediated via up-regulation of PI3K/Akt, Na2SeO3 has an effect of anti-apoptosis by down-regulating of PI3K/Akt signaling pathway.
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Affiliation(s)
- X A Du
- Institute of Endemic Diseases, Key Laboratory of Environment and Genes Related to Diseases of Education Ministry, Xi'an Jiaotong University Health Science Center, No. 76 Yanta West Road, Xi'an, Shaanxi 710061, PR China
| | - H M Wang
- Institute of Endemic Diseases, Key Laboratory of Environment and Genes Related to Diseases of Education Ministry, Xi'an Jiaotong University Health Science Center, No. 76 Yanta West Road, Xi'an, Shaanxi 710061, PR China
| | - X X Dai
- Institute of Endemic Diseases, Key Laboratory of Environment and Genes Related to Diseases of Education Ministry, Xi'an Jiaotong University Health Science Center, No. 76 Yanta West Road, Xi'an, Shaanxi 710061, PR China
| | - Y Kou
- School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, PR China
| | - R P Wu
- Institute of Endemic Diseases, Key Laboratory of Environment and Genes Related to Diseases of Education Ministry, Xi'an Jiaotong University Health Science Center, No. 76 Yanta West Road, Xi'an, Shaanxi 710061, PR China
| | - Q Chen
- Institute of Endemic Diseases, Key Laboratory of Environment and Genes Related to Diseases of Education Ministry, Xi'an Jiaotong University Health Science Center, No. 76 Yanta West Road, Xi'an, Shaanxi 710061, PR China
| | - J L Cao
- Institute of Endemic Diseases, Key Laboratory of Environment and Genes Related to Diseases of Education Ministry, Xi'an Jiaotong University Health Science Center, No. 76 Yanta West Road, Xi'an, Shaanxi 710061, PR China
| | - X Y Mo
- School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, PR China
| | - Y M Xiong
- Institute of Endemic Diseases, Key Laboratory of Environment and Genes Related to Diseases of Education Ministry, Xi'an Jiaotong University Health Science Center, No. 76 Yanta West Road, Xi'an, Shaanxi 710061, PR China.
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Chen Q, Liu D, Xiong YM, Wang ZL. The Effects of Gallium Chloride on Apoptosis Osteoporosis Model of Rats Caused by Tretinoin Acid. Value Health 2014; 17:A771-A772. [PMID: 27202840 DOI: 10.1016/j.jval.2014.08.320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Q Chen
- Xi'an Jiaotong University Health Science Center, xi'an, China
| | - D Liu
- the fifth hospital of Xi'an, xi'an, China
| | - Y M Xiong
- Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Z L Wang
- Xi'an Jiaotong University School of Medicine, Xi'an, China
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Liu D, Liu JY, Chen Q, Xiong YM, Wang ZL. The Effect of Dietary Selenium Intake in The Gene Expression of P38, P65, and Caspase-3 in Fluorosis Patients. Value Health 2014; 17:A771. [PMID: 27202841 DOI: 10.1016/j.jval.2014.08.318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- D Liu
- the fifth hospital of Xi'an, xi'an, China
| | - J Y Liu
- the fifth hospital of Xi'an, xi'an, China
| | - Q Chen
- Xi'an Jiaotong University Health Science Center, xi'an, China
| | - Y M Xiong
- Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Z L Wang
- Xi'an Jiaotong University School of Medicine, Xi'an, China
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Liu TJ, Prestigiacomo JC, Xiong YM, Adams PW. Exchange field-mediated magnetoresistance in the correlated insulator phase of Be films. Phys Rev Lett 2012; 109:147207. [PMID: 23083279 DOI: 10.1103/physrevlett.109.147207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Indexed: 06/01/2023]
Abstract
We present a study of the proximity effect between a ferromagnet and a paramagnetic metal of varying disorder. Thin beryllium films are deposited onto a 5 nm thick layer of the ferromagnetic insulator EuS. This bilayer arrangement induces an exchange field, H(ex), of a few tesla in low-resistance Be films with sheet resistance R≪R(Q), where R(Q)=h/e2 is the quantum resistance. We show that H(ex) survives in very high-resistance films and, in fact, appears to be relatively insensitive to the Be disorder. We exploit this fact to produce a giant low-field magnetoresistance in the correlated-insulator phase of Be films with R≫R(Q).
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Affiliation(s)
- T J Liu
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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Loh YL, Trivedi N, Xiong YM, Adams PW, Catelani G. Origin of excess low-energy states in a disordered superconductor in a Zeeman field. Phys Rev Lett 2011; 107:067003. [PMID: 21902361 DOI: 10.1103/physrevlett.107.067003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 06/25/2011] [Indexed: 05/31/2023]
Abstract
Tunneling density of states measurements of disordered superconducting Al films in high Zeeman fields reveal a significant population of subgap states which cannot be explained by standard BCS theory. We provide a natural explanation of these excess states in terms of a novel disordered Larkin-Ovchinnikov phase that occurs near the spin-paramagnetic transition at the Chandrasekhar-Clogston critical field. The disordered Larkin-Ovchinnikov superconductor is characterized by a pairing amplitude that changes sign at domain walls. These domain walls carry magnetization and support Andreev bound states that lead to distinct spectral signatures at low energy.
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Affiliation(s)
- Y L Loh
- Department of Physics, The Ohio State University, Columbus, 43210, USA
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Xiong YM, Stadler S, Adams PW, Catelani G. Spin-resolved tunneling studies of the exchange field in EuS/Al bilayers. Phys Rev Lett 2011; 106:247001. [PMID: 21770590 DOI: 10.1103/physrevlett.106.247001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Indexed: 05/31/2023]
Abstract
We use spin-resolved electron tunneling to study the exchange field in the Al component of EuS/Al bilayers, in both the superconducting and normal-state phases of the Al. Contrary to expectation, we show that the exchange field H(ex) is a nonlinear function of applied field, even in applied fields that are well beyond the EuS coercive field. Furthermore, the magnitude H(ex) is unaffected by the superconducting phase. In addition, H(ex) decreases significantly with increasing temperature in the temperature range of 0.1-1 K. We discuss these results in the context of recent theories of generalized spin-dependent boundary conditions at a superconductor-ferromagnet interface.
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Affiliation(s)
- Y M Xiong
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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13
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Xiong YM, Mo XY, Zou XZ, Song RX, Sun WY, Lu W, Chen Q, Yu YX, Zang WJ. Association study between polymorphisms in selenoprotein genes and susceptibility to Kashin-Beck disease. Osteoarthritis Cartilage 2010; 18:817-24. [PMID: 20178852 DOI: 10.1016/j.joca.2010.02.004] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Revised: 01/27/2010] [Accepted: 02/09/2010] [Indexed: 02/02/2023]
Abstract
OBJECTIVES Kashin-Beck disease (KBD) is a disabling osteoarthropathy involving growth cartilage endemic to selenium (Se)-deficient regions in China. Associations between genetic variation in selenoprotein genes and susceptibility to many diseases have recently been investigated but few studies have been performed on KBD. We found four genetic polymorphisms in selenoprotein genes and assessed their association with increased susceptibility to KBD. METHODS Four polymorphisms including GPX1 (rs1050450), TrxR2 (rs5748469), SEPP1 (rs7579) and DIO2 (rs225014) were analyzed for 161 KBD patients and 312 controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or tetra-primer amplification refractory mutation system PCR (Tetra-primer ARMS PCR). Glutathione peroxidase (GPX) activity in whole blood was measured using a GPX assay kit. The mRNA expression of GPX1, nuclear factor-kappaB (NF-kappaB) p65 and p53 in both whole blood and articular cartilage tissue were detected using Real-Time PCR. RESULTS The genotypic and allelic frequency of GPX1 Pro198Leu was significantly different between KBD patients and controls (P=0.013, P=0.037). A significant increased KBD risk was observed in individuals with Pro/Leu or Leu/Leu (odds ratio=1.781; 95% confidence interval: 1.127-2.814) compared with Pro/Pro. No association was observed between the other three single nucleotide polymorphisms (SNPs) and KBD risk. In addition, GPX enzyme activity in whole blood was lower in the KBD group (P<0.01), and the GPX activity in whole blood decreased significantly in a subgroup of individuals representing Pro/Leu and Leu/Leu compared to Pro/Pro (P<0.01). In whole blood and articular cartilage tissue samples of KBD patients, GPX1 and NF-kappaB p65 mRNA levels were lower (P<0.01) while p53 levels were higher (P<0.001). CONCLUSION GPX1 Pro198Leu is a potential genetic risk factor in the development of KBD and the GPX1 Leu allele is significantly associated with higher KBD risk among the Chinese Han population and with lower GPX enzyme activity. The expression of apoptosis related molecules in KBD patients significantly differs from controls.
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Affiliation(s)
- Y M Xiong
- Department of Pharmacology, College of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
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Xiong YM, Adams PW, Catelani G. Saturation of the anomalous Hall effect in critically disordered ultrathin CNi3 films. Phys Rev Lett 2010; 104:076806. [PMID: 20366906 DOI: 10.1103/physrevlett.104.076806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Indexed: 05/29/2023]
Abstract
We demonstrate that a distinct high-disorder anomalous Hall effect phase emerges at the correlated insulator threshold of ultrathin, amorphous, ferromagnetic CNi3 films. In the weak-localization regime, where the sheet conductance G>>e{2}/h, the anomalous Hall resistance of the films increases with increasing disorder and the Hall conductance scales as G{xy} proportional to G{phi} with phi=1.6. However, at sufficiently high disorder the system begins to enter the 2D correlated insulator regime, at which point the Hall resistance R{xy} abruptly saturates and the scaling exponent becomes phi=2. Tunneling measurements show that the saturation behavior is commensurate with the emergence of the 2D Coulomb gap, suggesting that e-e interactions mediate the high-disorder phase.
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Affiliation(s)
- Y M Xiong
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001, USA
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Drake BL, Capan C, Cho JY, Nambu Y, Kuga K, Xiong YM, Karki AB, Nakatsuji S, Adams PW, Young DP, Chan JY. Crystal growth, structure, and physical properties of Ln(Cu,Al)12 (Ln = Y, Ce, Pr, Sm, and Yb) and Ln(Cu, Ga)12 (Ln = Y, Gd-Er, and Yb). J Phys Condens Matter 2010; 22:066001. [PMID: 21389376 DOI: 10.1088/0953-8984/22/6/066001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Single crystals of Ln(Cu,Al)12 and Ln(Cu,Ga)12 compounds (Ln = Y, Ce-Nd, Sm, Gd-Ho, and Yb for Al and Ln = Y, Gd-Er, Yb for Ga) have been grown by flux-growth methods and characterized by means of single-crystal x-ray diffraction, complemented with microprobe analysis, magnetic susceptibility, resistivity and heat capacity measurements. Ln(Cu,Ga)12 and Ln(Cu,Al)12 of the ThMn12 structure type crystallize in the tetragonal I4/mmm space group with lattice parameters a approximately 8.59 Å and c approximately 5.15 Å and a approximately 8.75 Å and c approximately 5.13 Å for Ga and Al containing compounds, respectively. For aluminium containing compounds, magnetic susceptibility data show Curie-Weiss paramagnetism in the Ce and Pr analogues down to 50 K with no magnetic ordering down to 3 K, whereas the Yb analogue shows a temperature-independent Pauli paramagnetism. Sm(Cu,Al)12 orders antiferromagnetically at T(N)approximately 5 K and interestingly exhibits Curie-Weiss behaviour down to 10 K with no Van Vleck contribution to the susceptibility. Specific heat data show that Ce(Cu,Al)12 is a heavy fermion antiferromagnet with T(N) approximately 2 K and with an electronic specific heat coefficient γ0 as large as 390 mJ K2 mol(-1). In addition, this is the first report of Pr(Cu,Al)12 and Sm(Cu,Al)12 showing an enhanced mass (approximately 80 and 120 mJ K(2) mol(-1)). For Ga containing analogues, magnetic susceptibility data also show the expected Curie-Weiss behaviour from Gd to Er, with the Yb analogue being once again a Pauli paramagnet. The antiferromagnetic transition temperatures range over 12.5, 13.5, 6.7, and 3.4 K for Gd, Tb, Dy, and Er. Metallic behaviour is observed down to 3 K for all Ga and Al analogues. A large positive magnetoresistance up to 150% at 9 T is also observed for Dy(Cu,Ga)12. The structure, magnetic, and transport properties of these compounds will be discussed.
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Affiliation(s)
- Brenton L Drake
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
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Xiong YM, Adams PW, Catelani G. Measurement of conduction-electron polarization via the pairing resonance. Phys Rev Lett 2009; 103:067009. [PMID: 19792604 DOI: 10.1103/physrevlett.103.067009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Indexed: 05/28/2023]
Abstract
We show that the pairing resonance in the Pauli-limited normal state of ultrathin superconducting Al films provides a spin-resolved probe of conduction-electron polarization in thin magnetic films. A superconductor-insulator-ferromagnet tunneling junction is used to measure the density of states in supercritical parallel magnetic fields that are well beyond the Clogston-Chandresekhar limit, thus greatly extending the field range of the tunneling density of states technique. The applicability and limitations of using the pairing resonance as a spin probe are discussed.
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Affiliation(s)
- Y M Xiong
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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Xiong PK, Xu DS, Xiong YM. [A case of roundworm in the splenic artery]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2003; 19:324. [PMID: 12572059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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Abstract
The central region (residues 125-385) of the integrin beta(2) subunit is postulated to adopt an I-domain-like fold (the beta(2)I-domain) and to play a critical role in ligand binding and heterodimer formation. To understand structure-function relationships of this region of beta(2), a homolog-scanning mutagenesis approach, which entails substitution of nonconserved hydrophilic sequences within the beta(2)I-domain with their homologous counterparts of the beta(1)I-domain, has been deployed. This approach is based on the premise that beta(1) and beta(2) are highly homologous, yet recognize different ligands. Altogether, 16 segments were switched to cover the predicted outer surface of the beta(2)I-domain. When these mutant beta(2) subunits were transfected together with wild-type alpha(M) in human 293 cells, all 16 beta(2) mutants were expressed on the cell surface as heterodimers, suggesting that these 16 sequences within the beta(2)I-domain are not critically involved in heterodimer formation between the alpha(M) and beta(2) subunits. Using these mutant alpha(M)beta(2) receptors, we have mapped the epitopes of nine beta(2)I-domain specific mAbs, and found that they all recognized at least two noncontiguous segments within this domain. The requisite spatial proximity among these non-linear sequences to form the mAb epitopes supports a model of an I-domain-like fold for this region. In addition, none of the mutations that abolish the epitopes of the nine function-blocking mAbs, including segment Pro(192)-Glu(197), destroyed ligand binding of the alpha(M)beta(2) receptor, suggesting that these function-blocking mAbs inhibit alpha(M)beta(2) function allosterically. Given the recent reports implicating the segment equivalent to Pro(192)-Glu(197) in ligand binding by beta(3) integrins, these data suggest that ligand binding by the beta(2) integrins occurs via a different mechanism than beta(3). Finally, both the conformation of the beta(2)I-domain and C3bi binding activity of alpha(M)beta(2) were dependent on a high affinity Ca(2+) binding site (K(d) = 105 microm), which is most likely located within this region of beta(2).
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Affiliation(s)
- Y M Xiong
- Department of Vascular Biology, American Red Cross Holland Laboratory, Rockville, Maryland 20855, USA
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Shao F, Xiong YM, Zhu RH, Ling MH, Chi CW, Wang DC. Expression and purification of the BmK M1 neurotoxin from the scorpion Buthus martensii Karsch. Protein Expr Purif 1999; 17:358-65. [PMID: 10600453 DOI: 10.1006/prep.1999.1127] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The gene encoding a neurotoxin (BmK M1) from the scorpion Buthus martensii Karsch was expressed in Saccharomyces cerevisiae at a high level with the alcohol dehydrogenase promoter. SDS-PAGE of the culture confirmed expression and showed secretion into medium from yeast. Recombinant BmK M1 was purified rapidly and efficiently by ion exchange and gel filtration chromatography to homogeneity, produced a single band on tricine-SDS-PAGE, and processed the homologous N-terminus. Amino acid analysis and N-terminal sequencing demonstrated that the recombinant toxin was processed correctly from the alpha-mating factor leader sequence and was chemically identical to the native form. The expressed recombinant BmK M1 was toxic for mice, which indicated that it was biologically active. Quantitative estimation showed that recombinant BmK M1 had an LD(50) similar to that of the native toxin.
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Affiliation(s)
- F Shao
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
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Xiong YM, Lan ZD, Wang M, Liu B, Liu XQ, Fei H, Xu LG, Xia QC, Wang CG, Wang DC, Chi CW. Molecular characterization of a new excitatory insect neurotoxin with an analgesic effect on mice from the scorpion Buthus martensi Karsch. Toxicon 1999; 37:1165-80. [PMID: 10400300 DOI: 10.1016/s0041-0101(98)00253-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Besides the neurotoxins active on mammals, a new excitatory insect selective toxin with a mice analgesic activity was found and purified from the venom of the scorpion Buthus martensi Karsch (BmK) (Ji, Y.H., Mansuelle, P., Terakawa, S., Kopeyan, C., Yanaihara, N., Hsu, K., Rochat, H., 1996. Toxicon 34, 987; Luo, M.J., Xiong, Y.M., Wang, M., Wang, D.C., Chi, C.W., 1997. Toxicon 35, 723.). This peptide (designated as BmK IT-AP) is composed of 72 amino acid residues. Its primary structure was determined by automated Edman degradation of the N-terminal part of the reduced and S-carboxamidemethylated protein and its lysylendopeptidase degraded fragments. Based on the determined sequence, the gene specific primers were designed and synthesized for 3' and 5' RACE (rapid amplification of cDNA ends). Their partial cDNA fragments obtained by 3' and 5' RACEwere cloned and sequenced and the full length cDNA sequence of BmK IT-AP was then completed by overlapping their two partial cDNA sequences. It encodes a precursor of 90 amino acid residues: a signal peptide of 18 residues and a mature peptide of 72 residues which are consistent with the determined protein sequence of BmK IT-AP. The genomic DNA of the peptide was also amplified by PCR from the scorpion genomic DNA and sequenced, which is a first report on the genomic structure of a scorpion toxin specific for insects. Its sequence revealed an intron of 590 bp inserted in the end part of the signal peptide. The peptide caused a fast excitatory contraction paralysis on house fly larvae. Furthermore, the peptide also showed an obvious analgesic effect on mice, as assayed by using a twisting test model. This effect of BmK IT-AP well characterized at molecular level is first reported among the known scorpion insect neurotoxins.
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Affiliation(s)
- Y M Xiong
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry, Academia Sinica, People's Republic of China
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Shao F, Hu Z, Xiong YM, Huang QZ, Zhu RH, Wang DC. A new antifungal peptide from the seeds of Phytolacca americana: characterization, amino acid sequence and cDNA cloning. Biochim Biophys Acta 1999; 1430:262-8. [PMID: 10082954 DOI: 10.1016/s0167-4838(99)00013-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An antifungal peptide from seeds of Phytolacca americana, designated PAFP-s, has been isolated. The peptide is highly basic and consists of 38 residues with three disulfide bridges. Its molecular mass of 3929.0 was determined by mass spectrometry. The complete amino acid sequence was obtained from automated Edman degradation, and cDNA cloning was successfully performed by 3'-RACE. The deduced amino acid sequence of a partial cDNA corresponded to the amino acid sequence from chemical sequencing. PAFP-s exhibited a broad spectrum of antifungal activity, and its activities differed among various fungi. PAFP-s displayed no inhibitory activity towards Escherichia coli. PAFP-s shows significant sequence similarities and the same cysteine motif with Mj-AMPs, antimicrobial peptides from seeds of Mirabilis jalapa belonging to the knottin-type antimicrobial peptide.
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Affiliation(s)
- F Shao
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
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Abstract
The full-length cDNA of an excitatory insect selective neurotoxin was amplified from total cDNAs of venomous glands of the scorpion Buthus martensi Karsch (BmK) using the 3'RACE and 5'RACE (rapid amplification of cDNA ends, RACE) method and sequenced. The cDNA encoded a precursor of the insect toxin of 88 amino acid residues, including a signal peptide of 18 residues and a mature toxin of 70 residues. The cDNA deduced sequence of this toxin was homologous with the determined amino acid sequence of BmK IT1, an excitatory insect toxin purified from the scorpion venom, except for three different residues, two at the positions 24-25, and another in the COOH-terminus of the toxin. Among them the COO-terminal residue Gly in the cDNA deduced sequence was predominantly different from the conserved residue Asn found in other known scorpion excitatory insect toxins.
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Affiliation(s)
- Y M Xiong
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry, Academia Sinica, China
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Abstract
The cDNA library of venomous glands of the scorpion Buthus martensii Karsch (BmK) was constructed. A cDNA encoding a mammalian neurotoxin corresponding to the known alpha-type toxin, BmK M1, was amplified by polymerase chain reaction (PCR) and cloned, and its full-length sequence was determined. The open reading frame encoded the precursor of BmK M1 with 84 amino acid residues, including a signal peptide of 19 residues, a mature toxin of 64 residues and an additional C-terminal residue Arg which might be cleaved off by proteinase postprocessing immediately after protein synthesis. Based on the determined cDNA sequence and using the total DNA of the scorpion as a template, the gene of BmK M1 was also amplified by PCR and sequenced. The genomic DNA sequence revealed an intron of 408 base pairs present within the signal peptide region. Both the intron and exon of BmK M1 share about 75% similarity with those of AaH I' another alpha-type mammalian neurotoxin in the scorpion Androctonus australis Hector.
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Affiliation(s)
- Y M Xiong
- Beijing Institute of Biophysics, Academia Sinica, P.R. China
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Luo MJ, Xiong YM, Wang M, Wang DC, Chi CW. Purification and sequence determination of a new neutral mammalian neurotoxin from the scorpion Buthus martensii Karsch. Toxicon 1997; 35:723-31. [PMID: 9203297 DOI: 10.1016/s0041-0101(96)00146-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A new neutral mammalian neurotoxin, designated BmK M4, with an isoelectric point (pI) of 7.6 and a relatively low toxicity (LD50 = 4.0 +/- 0.25 microgram/g mice, i.v.) was purified from the venom of scorpion Buthus martensii Karsch (BmK). The complete amino acid sequence of the toxin composed of 64 amino acid residues was determined by automated Edman degradation of the N-terminal part of the reduced and S-carboxamidomethylated protein (up to 30 amino acid residues) and its peptide fragments degraded by lysylendopeptidase or Staphylococcus aureus Va protease. The calculated mol. wt based on the amino acid composition was 7001. By comparison with the sequences of other basic BmK mammalian neurotoxins, it was concluded that the weaker toxicity and lower pI value of BmK M4 might be the result of mutations H10E, R18G and K28D. The sequence comparison of BmK M4 with an acidic toxin, BmK M8, showed that the weakest toxicity and acidic property of BmK M8 may be the consequence of mutations K8D, D53A, V55E and V59E. The substitution of 21 Gly in BmK M4 for Tyrin other BmK toxins may also be of importance. In their tertiary structures, these mutated charged residues are mainly distributed in the surface (face B) that is roughly opposite to the "conserved hydrophobic surface" (face A) proposed by Fontecilla-Camps et al. in 1982. Therefore the toxin-receptor interaction may take a multiposition mode.
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Affiliation(s)
- M J Luo
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry, Academia Sinica, P.R. China
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Xiong YM, Snyder PG, Woollam JA, Al-Jumaily GA, Gagliardi FJ, Mizerka LJ. Optical Characterization of Silicon Oxynitride Thin Films by Variable Angle Spectroscopic Ellipsometry. SURF INTERFACE ANAL 1992. [DOI: 10.1002/sia.740180211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Snyder PG, Xiong YM. Study of concentration-dependent dielectric properties of n-type GaAs using variable angle spectroscopic ellipsometry. SURF INTERFACE ANAL 1992. [DOI: 10.1002/sia.740180208] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Snyder PG, Xiong YM, Woollam JA, Krosche ER, Strausser Y. Characterization of polycrystalline silicon thin-film multilayers by variable angle spectroscopic ellipsometry. SURF INTERFACE ANAL 1992. [DOI: 10.1002/sia.740180209] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Xiong YM, Xu SZ, Slakey LL. Modulation of response to adenosine in vascular smooth muscle cells cultured in defined medium. In Vitro Cell Dev Biol 1991; 27A:355-62. [PMID: 1649162 DOI: 10.1007/bf02630954] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cultured pig aortic smooth muscle cells maintain a viable, quiescent state in a chemically defined medium that contains 10(-6) M insulin, 5 micrograms/ml transferrin, and 0.2 mM ascorbate. DNA synthesis and DNA content were determined by measuring tritiated thymidine incorporation and DNA-binding to the fluorescent probe 4',6-diamidino-2-phenylindole, respectively. The majority of the population of cells in defined medium cultures were diploid. Tritiated thymidine uptake in cells in defined medium was one-tenth that observed in cells in fetal bovine serum-containing medium. The study of cellular cyclic AMP level in response to extracellular adenosine stimulation in dividing cells and quiescent cells showed that cells in defined medium had a lower extent of response to adenosine compared to cells cultured in serum-containing medium. Both the cell growth index and the response to adenosine of cells cultured in defined medium were reversible after replacing the medium with 10% fetal bovine serum-containing medium, which suggests that the cells in defined medium were healthy and were capable of modulating cellular metabolism depending on culture conditions.
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Affiliation(s)
- Y M Xiong
- Department of Biochemistry, University of Massachusetts, Amherst 01003
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