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Goldstone JV, Lamb DC, Kelly SL, Lepesheva GI, Stegeman JJ. Structural modeling of cytochrome P450 51 from a deep-sea fish points to a novel structural feature in other CYP51s. J Inorg Biochem 2023; 245:112241. [PMID: 37209461 PMCID: PMC10330650 DOI: 10.1016/j.jinorgbio.2023.112241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/13/2023] [Accepted: 04/27/2023] [Indexed: 05/22/2023]
Abstract
Cytochromes P450 (CYP), enzymes involved in the metabolism of endogenous and xenobiotic substrates, provide an excellent model system to study how membrane proteins with unique functions have catalytically adapted through evolution. Molecular adaptation of deep-sea proteins to high hydrostatic pressure remains poorly understood. Herein, we have characterized recombinant cytochrome P450 sterol 14α-demethylase (CYP51), an essential enzyme of cholesterol biosynthesis, from an abyssal fish species, Coryphaenoides armatus. C. armatus CYP51 was heterologously expressed in Escherichia coli following N-terminal truncation and purified to homogeneity. Recombinant C. armatus CYP51 bound its sterol substrate lanosterol giving a Type I binding spectra (KD 15 μM) and catalyzed lanosterol 14α-demethylation turnover at 5.8 nmol/min/nmol P450. C. armatus CYP51 also bound the azole antifungals ketoconazole (KD 0.12 μM) and propiconazole (KD 0.54 μM) as determined by Type II absorbance spectra. Comparison of C. armatus CYP51 primary sequence and modeled structures with other CYP51s identified amino acid substitutions that may confer an ability to function under pressures of the deep sea and revealed heretofore undescribed internal cavities in human and other non-deep sea CYP51s. The functional significance of these cavities is not known. PROLOGUE: This paper is dedicated in memory of Michael Waterman and Tsuneo Omura, who as good friends and colleagues enriched our lives. They continue to inspire us.
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Affiliation(s)
- Jared V Goldstone
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - David C Lamb
- Faculty of Medicine, Health and Life Science, Swansea University, Swansea SA2 8PP, UK
| | - Steven L Kelly
- Faculty of Medicine, Health and Life Science, Swansea University, Swansea SA2 8PP, UK
| | - Galina I Lepesheva
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - John J Stegeman
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
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2
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Chen X, Zheng J, Zhang J, Duan M, Xu H, Zhao W, Yang Y, Wang C, Xu Y. Exposure to difenoconazole induces reproductive toxicity in zebrafish by interfering with gamete maturation and reproductive behavior. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:155610. [PMID: 35504380 DOI: 10.1016/j.scitotenv.2022.155610] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 04/14/2022] [Accepted: 04/26/2022] [Indexed: 06/14/2023]
Abstract
Difenoconazole (DCZ) is a triazole fungicide that negatively affects aquatic organisms and humans. However, data regarding the reproductive toxicity of DCZ are insufficient. In this study, we used zebrafish (from 2 h post-fertilization [hpf] to adulthood) as a model to evaluate whether DCZ at environmentally relevant concentrations (0.1, 1.0, and 10.0 μg/L) induces reproductive toxicity. After exposure to DCZ, egg production and fertilization rates were reduced by 1.0 and 10.0 μg/L. A significant decrease in gamete frequency (late vitellogenic oocytes and spermatozoa) was observed at 10.0 μg/L. The concentrations of 17β-estradiol (E2), testosterone (T), and vitellogenin (VTG) were disrupted in females and males by 1.0 and 10.0 μg/L. Exposure to 10.0 μg/L DCZ significantly inhibited the contact time between female and male fish, which was mainly achieved by affecting male fish. The transcription of genes involved in the hypothalamus-pituitary-gonad (HPG) axis was significantly changed after treatment with DCZ. Overall, these data show that the endocrine-disrupting effect of DCZ on the zebrafish HPG axis inhibited gamete maturation and disrupted reproductive behavior, reducing fertility.
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Affiliation(s)
- Xiangguang Chen
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Sciences, China Agricultural University, Beijing 100193, China
| | - Junyue Zheng
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Sciences, China Agricultural University, Beijing 100193, China
| | - Jie Zhang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Sciences, China Agricultural University, Beijing 100193, China
| | - Manman Duan
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Sciences, China Agricultural University, Beijing 100193, China
| | - Hao Xu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Sciences, China Agricultural University, Beijing 100193, China
| | - Wentian Zhao
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Sciences, China Agricultural University, Beijing 100193, China
| | - Yang Yang
- State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Chengju Wang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Sciences, China Agricultural University, Beijing 100193, China.
| | - Yong Xu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Sciences, China Agricultural University, Beijing 100193, China
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3
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Mashanov V, Machado DJ, Reid R, Brouwer C, Kofsky J, Janies DA. Twinkle twinkle brittle star: the draft genome of Ophioderma brevispinum (Echinodermata: Ophiuroidea) as a resource for regeneration research. BMC Genomics 2022; 23:574. [PMID: 35953768 PMCID: PMC9367165 DOI: 10.1186/s12864-022-08750-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 07/08/2022] [Indexed: 12/13/2022] Open
Abstract
Background Echinoderms are established models in experimental and developmental biology, however genomic resources are still lacking for many species. Here, we present the draft genome of Ophioderma brevispinum, an emerging model organism in the field of regenerative biology. This new genomic resource provides a reference for experimental studies of regenerative mechanisms. Results We report a de novo nuclear genome assembly for the brittle star O. brevispinum and annotation facilitated by the transcriptome assembly. The final assembly is 2.68 Gb in length and contains 146,703 predicted protein-coding gene models. We also report a mitochondrial genome for this species, which is 15,831 bp in length, and contains 13 protein-coding, 22 tRNAs, and 2 rRNAs genes, respectively. In addition, 29 genes of the Notch signaling pathway are identified to illustrate the practical utility of the assembly for studies of regeneration. Conclusions The sequenced and annotated genome of O. brevispinum presented here provides the first such resource for an ophiuroid model species. Considering the remarkable regenerative capacity of this species, this genome will be an essential resource in future research efforts on molecular mechanisms regulating regeneration. Supplementary Information The online version contains supplementary material available at (10.1186/s12864-022-08750-y).
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Affiliation(s)
- Vladimir Mashanov
- Wake Forest Institute for Regenerative Medicine, 391 Technology Way, Winston-Salem, 27101, NC, USA. .,University of North Florida, Department of Biology, 1 UNF Drive, Jacksonville, 32224, FL, USA.
| | - Denis Jacob Machado
- University of North Carolina at Charlotte, College of Computing and Informatics, Department of Bioinformatics and Genomics, 9201 University City Blvd, Charlotte, 28223, NC, USA
| | - Robert Reid
- University of North Carolina at Charlotte, College of Computing and Informatics, North Carolina Research Campus, 150 Research Campus Drive, Kannapolis, 28081, NC, USA
| | - Cory Brouwer
- University of North Carolina at Charlotte, College of Computing and Informatics, North Carolina Research Campus, 150 Research Campus Drive, Kannapolis, 28081, NC, USA
| | - Janice Kofsky
- University of North Carolina at Charlotte, College of Computing and Informatics, Department of Bioinformatics and Genomics, 9201 University City Blvd, Charlotte, 28223, NC, USA
| | - Daniel A Janies
- University of North Carolina at Charlotte, College of Computing and Informatics, Department of Bioinformatics and Genomics, 9201 University City Blvd, Charlotte, 28223, NC, USA
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4
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Abstract
The cytochrome P450 (CYP) superfamily is a diverse and important enzyme family, playing a central role in chemical defense and in synthesis and metabolism of major biological signaling molecules. The CYPomes of four cnidarian genomes (Hydra vulgaris, Acropora digitifera, Aurelia aurita, Nematostella vectensis) were annotated; phylogenetic analyses determined the evolutionary relationships amongst the sequences and with existing metazoan CYPs. 155 functional CYPs were identified and 90 fragments. Genes were from 24 new CYP families and several new subfamilies; genes were in 9 of the 12 established metazoan CYP clans. All species had large expansions of clan 2 diversity, with H. vulgaris having reduced diversity for both clan 3 and mitochondrial clan. We identified potential candidates for xenobiotic metabolism and steroidogenesis. That each genome contained multiple, novel CYP families may reflect the large evolutionary distance within the cnidarians, unique physiology in the cnidarian classes, and/or different ecology of the individual species.
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Shang J, Ma S, Zang C, Bao X, Wang Y, Zhang D. Gut microbiota mediates the absorption of FLZ, a new drug for Parkinson's disease treatment. Acta Pharm Sin B 2021; 11:1213-1226. [PMID: 34094829 PMCID: PMC8148066 DOI: 10.1016/j.apsb.2021.01.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 10/04/2020] [Accepted: 11/03/2020] [Indexed: 01/07/2023] Open
Abstract
The gut microbiota plays an important role in regulating the pharmacokinetics and pharmacodynamics of many drugs. FLZ, a novel squamosamide derivative, has been shown to have neuroprotective effects on experimental Parkinson's disease (PD) models. FLZ is under phase Ⅰ clinical trial now, while the underlying mechanisms contributing to the absorption of FLZ are still not fully elucidated. Due to the main metabolite of FLZ was abundant in feces but rare in urine and bile of mice, we focused on the gut microbiota to address how FLZ was metabolized and absorbed. In vitro studies revealed that FLZ could be exclusively metabolized to its major metabolite M1 by the lanosterol 14 alpha-demethylase (CYP51) in the gut microbiota, but was almost not metabolized by any other metabolism-related organs, such as liver, kidney, and small intestine. M1 was quickly absorbed into the blood and then remethylated to FLZ by catechol O-methyltransferase (COMT). Notably, dysbacteriosis reduced the therapeutic efficacy of FLZ on the PD mouse model by inhibiting its absorption. The results show that the gut microbiota mediate the absorption of FLZ through a FLZ-M1-FLZ circulation. Our research elucidates the vital role of the gut microbiota in the absorption of FLZ and provides a theoretical basis for clinical pharmacokinetic studies and clinical application of FLZ in the treatment of PD.
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Affiliation(s)
| | | | | | - Xiuqi Bao
- Corresponding authors. Tel./fax: +86 10 63165203.
| | - Yan Wang
- Corresponding authors. Tel./fax: +86 10 63165203.
| | - Dan Zhang
- Corresponding authors. Tel./fax: +86 10 63165203.
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6
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Katti PA, Goundadkar BB. Azole pharmaceuticals induce germinal vesicle breakdown (GVBD) in preovulatory oocytes of zebrafish (Danio rerio): an in vitro study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:3694-3702. [PMID: 32929672 DOI: 10.1007/s11356-020-10719-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 09/02/2020] [Indexed: 06/11/2023]
Abstract
Azoles, the antifungal pharmaceuticals are emerging as a new class of water contaminants with a potential to influence the endocrine physiology of surrounding aquatic fauna. In this study, we made an attempt to assess the relative efficacy of widely used azoles belonging to two subclasses, i.e., (i) triazoles (letrozole, fluconazole, itraconazole) and (ii) imidazoles (ketaconazole, ornidazole, clotrimazole), on the onset of germinal vesicle breakdown (GVBD) (an initial step in the final maturation of oocytes) in fully grown preovulatory oocytes of zebrafish (Danio rerio) using an in vitro model. Oocytes (> 650 μm) isolated manually from gravid ovaries were exposed to (i) 0.01 and/or 0.1, 1.0, 5.0, 10, 15, and 20 ng/ml and (ii) 1.0, 2.0, 3.0, 4.0, and 5.0 μg/ml of drugs. Zebrafish Ringer's solution (vehicle) and 0.01% ethyl alcohol (solvent) were used as negative controls. 17α, 20 β-Dihydroxy-4-pregnen-3-one (17α-DHP) and diethylstibestrol (DES), potent inducers of GVBD in fish, were used as positive controls. GVBD was scored hourly from 0-6 h. In negative controls, there were no indications of GVBD even at the 6th hour, while in 17α-DHP- and DES-exposed oocytes, GVBD was initiated from the 1st hour, reaching 80% and 76% respectively at the 6th hour. Among azoles, letrozole induced GVBD in 73-85%, fluconazole (30-33%), itraconazole (23-33%), ketaconazole (46-53%), ornidazole (36-40%), and clotrimazole (30-33%) of oocytes. These results suggest that azole pharmaceuticals induce GVBD in fish oocytes that may be attributed to their variable degree of cytochrome P450 enzyme inhibitor activity.
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7
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Heusinkveld HJ, Schoonen WG, Hodemaekers HM, Nugraha A, Sirks JJ, Veenma V, Sujan C, Pennings JL, Wackers PF, Palazzolo L, Eberini I, Rorije E, van der Ven LT. Distinguishing mode of action of compounds inducing craniofacial malformations in zebrafish embryos to support dose-response modeling in combined exposures. Reprod Toxicol 2020; 96:114-127. [DOI: 10.1016/j.reprotox.2020.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 05/26/2020] [Accepted: 06/01/2020] [Indexed: 02/06/2023]
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8
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Evaluating the Effect of Azole Antifungal Agents on the Stress Response and Nanomechanical Surface Properties of Ochrobactrum anthropi Aspcl2.2. Molecules 2020; 25:molecules25153348. [PMID: 32717971 PMCID: PMC7435821 DOI: 10.3390/molecules25153348] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/17/2020] [Accepted: 07/20/2020] [Indexed: 12/03/2022] Open
Abstract
Azole antifungal molecules are broadly used as active ingredients in various products, such as pharmaceuticals and pesticides. This promotes their release into the natural environment. The detailed mechanism of their influence on the biotic components of natural ecosystems remains unexplored. Our research aimed to examine the response of Ochrobactrum anthropi AspCl2.2 to the presence of four azole antifungal agents (clotrimazole, fluconazole, climbazole, epoxiconazole). The experiments performed include analysis of the cell metabolic activity, cell membrane permeability, total glutathione level and activity of glutathione S-transferases. These studies allowed for the evaluation of the cells’ oxidative stress response to the presence of azole antifungals. Moreover, changes in the nanomechanical surface properties, including adhesive and elastic features of the cells, were investigated using atomic force microscopy (AFM) and spectrophotometric methods. The results indicate that the azoles promote bacterial oxidative stress. The strongest differences were noted for the cells cultivated with fluconazole. The least toxic effect has been attributed to climbazole. AFM observations unraveled molecular details of bacterial cell texture, structure and surface nanomechanical properties. Antifungals promote the nanoscale modification of the bacterial cell wall. The results presented provided a significant insight into the strategies used by environmental bacterial cells to survive exposures to toxic azole antifungal agents.
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9
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Sun Y, Cao Y, Tong L, Tao F, Wang X, Wu H, Wang M. Exposure to prothioconazole induces developmental toxicity and cardiovascular effects on zebrafish embryo. CHEMOSPHERE 2020; 251:126418. [PMID: 32443233 DOI: 10.1016/j.chemosphere.2020.126418] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/29/2020] [Accepted: 03/03/2020] [Indexed: 06/11/2023]
Abstract
Prothioconazole is a fungicide that has been widely used in general agriculture and livestock husbandry. This study evaluated the acute toxicity of prothioconazole to zebrafish embryos by assessing their hatching rate and malformation when exposed to different concentrations of prothioconazole. The 96 h-LC50 value of zebrafish embryos was 1.70 mg/L. Upon exposure to 0.85 mg/L, the mortality rate of the embryos significantly increased while their hatching rate decreased significantly. At prothioconazole concentrations higher than 0.43 mg/L, developmental morphologic abnormalities such as heart and yolk-sac edema, spine curvature, tail deformity, shortened body length and decreased eye area were observed. The heart rate of embryos decreased in a dose-dependent fashion during the exposure time. Prothioconazole exposure also resulted in increased rates of cardiac malformation detected by significant increase in the distance between the sinus venosus and bulbus arteriosus and the pericardium area. Moreover, the expression levels of genes related to cardiac development (amhc, vmhc, fli1, hand2, gata4, nkx2.5, tbx5 and atp2a2a) were significantly altered after exposure to prothioconazole. Indeed, this study revealed the adverse effects on the developmental and cardiovascular system of zebrafish embryo caused by prothioconazole. It further elucidated the risk of prothioconazole exposure to vertebrate cardiovascular toxicity. As such, it provides a theoretical foundation for pesticide risk management measures.
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Affiliation(s)
- Yongqi Sun
- School of Agricultural and Food Science, Zhejiang Agriculture & Forestry University, Hangzhou, China
| | - Yi Cao
- School of Agricultural and Food Science, Zhejiang Agriculture & Forestry University, Hangzhou, China
| | - Lili Tong
- School of Agricultural and Food Science, Zhejiang Agriculture & Forestry University, Hangzhou, China
| | - Fangyi Tao
- School of Agricultural and Food Science, Zhejiang Agriculture & Forestry University, Hangzhou, China
| | - Xiaonan Wang
- School of Agricultural and Food Science, Zhejiang Agriculture & Forestry University, Hangzhou, China
| | - Huiming Wu
- School of Agricultural and Food Science, Zhejiang Agriculture & Forestry University, Hangzhou, China.
| | - Mengcen Wang
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Pesticide & Environmental Toxicology, Zhejiang University, Hangzhou, China.
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10
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Jović O, Šmuc T. Combined Machine Learning and Molecular Modelling Workflow for the Recognition of Potentially Novel Fungicides. Molecules 2020; 25:molecules25092198. [PMID: 32397151 PMCID: PMC7249108 DOI: 10.3390/molecules25092198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/02/2020] [Accepted: 05/06/2020] [Indexed: 12/31/2022] Open
Abstract
Novel machine learning and molecular modelling filtering procedures for drug repurposing have been carried out for the recognition of the novel fungicide targets of Cyp51 and Erg2. Classification and regression approaches on molecular descriptors have been performed using stepwise multilinear regression (FS-MLR), uninformative-variable elimination partial-least square regression, and a non-linear method called Forward Stepwise Limited Correlation Random Forest (FS-LM-RF). Altogether, 112 prediction models from two different approaches have been built for the descriptor recognition of fungicide hit compounds. Aiming at the fungal targets of sterol biosynthesis in membranes, antifungal hit compounds have been selected for docking experiments from the Drugbank database using the Autodock4 molecular docking program. The results were verified by Gold Protein-Ligand Docking Software. The best-docked conformation, for each high-scored ligand considered, was submitted to quantum mechanics/molecular mechanics (QM/MM) gradient optimization with final single point calculations taking into account both the basis set superposition error and thermal corrections (with frequency calculations). Finally, seven Drugbank lead compounds were selected based on their high QM/MM scores for the Cyp51 target, and three were selected for the Erg2 target. These lead compounds could be recommended for further in vitro studies.
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11
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Comparative Transcriptome Analysis of Gill Tissue in Response to Hypoxia in Silver Sillago ( Sillago sihama). Animals (Basel) 2020; 10:ani10040628. [PMID: 32268576 PMCID: PMC7222756 DOI: 10.3390/ani10040628] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/05/2020] [Accepted: 04/05/2020] [Indexed: 12/11/2022] Open
Abstract
Silver sillago (Sillago sihama) is a commercially important marine fish species in East Asia. In this study, we compared the transcriptome response to hypoxia stress in the gill tissue of S. sihama. The fish were divided into four groups, such as 1 h of hypoxia (hypoxia1h, DO = 1.5 ± 0.1 mg/L), 4 h of hypoxia (hypoxia4h, DO = 1.5 ± 0.1 mg/L), 4 h of reoxygen (reoxygen4h, DO = 8.0 ± 0.2 mg/L) after 4 h of hypoxia (DO = 1.5 mg/L), and normoxia or control (DO = 8.0 ± 0.2 mg/L) groups. Compared to the normoxia group, a total of 3550 genes were identified as differentially expressed genes (DEGs) (log2foldchange > 1 and padj < 0.05), including 1103, 1451 and 996 genes in hypoxia1h, hypoxia4h and reoxygen4h groups, respectively. Only 247 DEGs were differentially co-expressed in all treatment groups. According to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, DEGs were significantly enriched in steroid biosynthesis, biosynthesis of amino acids, glutathione metabolism and metabolism of xenobiotics by cytochrome P450, ferroptosis and drug metabolism-cytochrome P450 pathways. Of these, the cytochrome P450 (CYP) and glutathione S-transferase (GST) gene families were widely expressed. Our study represents the insights into the underlying molecular mechanisms of hypoxia stress.
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12
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Rozhon W, Akter S, Fernandez A, Poppenberger B. Inhibitors of Brassinosteroid Biosynthesis and Signal Transduction. Molecules 2019; 24:E4372. [PMID: 31795392 PMCID: PMC6930552 DOI: 10.3390/molecules24234372] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/19/2022] Open
Abstract
Chemical inhibitors are invaluable tools for investigating protein function in reverse genetic approaches. Their application bears many advantages over mutant generation and characterization. Inhibitors can overcome functional redundancy, their application is not limited to species for which tools of molecular genetics are available and they can be applied to specific tissues or developmental stages, making them highly convenient for addressing biological questions. The use of inhibitors has helped to elucidate hormone biosynthesis and signaling pathways and here we review compounds that were developed for the plant hormones brassinosteroids (BRs). BRs are steroids that have strong growth-promoting capacities, are crucial for all stages of plant development and participate in adaptive growth processes and stress response reactions. In the last two decades, impressive progress has been made in BR inhibitor development and application, which has been instrumental for studying BR modes of activity and identifying and characterizing key players. Both, inhibitors that target biosynthesis, such as brassinazole, and inhibitors that target signaling, such as bikinin, exist and in a comprehensive overview we summarize knowledge and methodology that enabled their design and key findings of their use. In addition, the potential of BR inhibitors for commercial application in plant production is discussed.
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Affiliation(s)
- Wilfried Rozhon
- Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Liesel-Beckmann-Straße 1, 85354 Freising, Germany
| | | | | | - Brigitte Poppenberger
- Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Liesel-Beckmann-Straße 1, 85354 Freising, Germany
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13
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Kumar N, Awoyemi O, Willis A, Schmitt C, Ramalingam L, Moustaid-Moussa N, Crago J. Comparative Lipid Peroxidation and Apoptosis in Embryo-Larval Zebrafish Exposed to 3 Azole Fungicides, Tebuconazole, Propiconazole, and Myclobutanil, at Environmentally Relevant Concentrations. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:1455-1466. [PMID: 30919521 DOI: 10.1002/etc.4429] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 02/04/2019] [Accepted: 03/25/2019] [Indexed: 06/09/2023]
Abstract
Azole fungicides have entered the aquatic environment through agricultural and residential runoff. In the present study, we compared the off-target toxicity of tebuconazole, propiconazole, and myclobutanil using embryo-larval zebrafish as a model. The aim of the present study was to investigate the relative toxicity of tebuconazole, propiconazole, and myclobutanil using multiple-level endpoints such as behavioral endpoints and enzymatic and molecular biomarkers associated with their mode of action. Zebrafish embryos were exposed to azoles at environmentally relevant and high concentrations, 0.3, 1.0, and 1000 µg/L, starting at 5 h postfertilization (hpf) up to 48 hpf, as well as 5 d postfertilization (dpf). Relative mRNA expressions of cytochrome P450 family 51 lanosterol-14α-demethylase, glutathione S-transferase, caspase 9, phosphoprotein p53, and BCL2-associated X protein were measured to assess toxicity attributable to fungicides at the mRNA level, whereas caspase 3/7 (apoptosis) and 3,4-methylenedioxyamphetamine (lipid peroxidation) levels were measured at the enzymatic level. Furthermore, mitochondrial dysfunction was measure through the Mito Stress test using the Seahorse XFe24 at 48 hpf. In addition, light to dark movement behavior was monitored at 5 dpf using Danio Vision® to understand adverse effects at the organismal level. There was no significant difference in the light to dark behavior with exposure to azoles compared to controls. The molecular biomarkers indicated that propiconazole and myclobutanil induced lipid peroxidation, oxidative stress, and potentially apoptosis at environmentally relevant concentrations (0.3 and 1 µg/L). The results from the mitochondrial respiration assay indicated a slight decrease in spare respiratory capacity with an acute exposure (48 hpf) to all 3 azoles at 1000 µg/L. Based on the present results, propiconazole and myclobutanil are acutely toxic compared to tebuconazole in aquatic organisms at environmentally relevant concentrations. Environ Toxicol Chem 2019;38:1455-1466. © 2019 SETAC.
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Affiliation(s)
- N Kumar
- Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA
| | - O Awoyemi
- Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA
| | - A Willis
- Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA
| | - C Schmitt
- Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA
| | - L Ramalingam
- Department of Nutritional Sciences, Texas Tech University, Lubbock, Texas, USA
| | - N Moustaid-Moussa
- Department of Nutritional Sciences, Texas Tech University, Lubbock, Texas, USA
| | - J Crago
- Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA
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14
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Ferain A, Bonnineau C, Neefs I, Das K, Larondelle Y, Rees JF, Debier C, Lemaire B. Transcriptional effects of phospholipid fatty acid profile on rainbow trout liver cells exposed to methylmercury. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 199:174-187. [PMID: 29649756 DOI: 10.1016/j.aquatox.2018.03.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 03/16/2018] [Accepted: 03/20/2018] [Indexed: 06/08/2023]
Abstract
Lipids, and their constitutive fatty acids, are key nutrients for fish health as they provide energy, maintain cell structure, are precursors of signalling molecules and act as nuclear receptor ligands. These specific roles may be of crucial importance in a context of exposure to pollutants. We recently showed that the fatty acid profile of rainbow trout liver cell phospholipids modulates sensitivity to an acute methylmercury challenge. In order to investigate mechanisms of effects, we herein tested whether specific polyunsaturated fatty acids (PUFAs) may protect cells from methylmercury through decreasing intracellular mercury accumulation and/or enhancing cellular defences (e.g. via modulation of gene expression patterns). We also investigated the inverse relationship and assessed the impact of methylmercury on cellular fatty acid metabolism. To do so, the fatty acid composition of rainbow trout liver cell phospholipids was first modified by incubating them in a medium enriched in a specific PUFA from either the n-3 family (alpha-linolenic acid, ALA; eicosapentaenoic acid, EPA) or the n-6 family (linoleic acid, LA; arachidonic acid, AA). Cells were then exposed to methylmercury (0.15 or 0.50 μM) for 24 h and sampled thereafter for assessing phospholipid fatty acid profile, intracellular total mercury burden, and expression pattern of genes involved in fatty acid metabolism, synthesis of PUFA-derived signalling molecules and stress response. We observed that cells incorporated the given PUFA and some biotransformation products in their phospholipids. Methylmercury had few impacts on this cellular phospholipid composition. None of the PUFA enrichments affected the cellular mercury burden, suggesting that the previously observed cytoprotection conferred by ALA and EPA was not linked to a global decrease in cellular accumulation of mercury. Fatty acid enrichments and methylmercury exposure both modulated gene expression patterns. Genes involved in the synthesis of PUFA-derived signalling molecules, in stress response and the orphan cytochrome P450 20A1 were identified as possible sites of interaction between fatty acids and methylmercury in rainbow trout liver cells.
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Affiliation(s)
- Aline Ferain
- Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve, Belgium.
| | - Chloé Bonnineau
- Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve, Belgium; Irstea, UR RiverLy, Centre de Lyon-Villeurbanne, 5, 69625 Villeurbanne, France
| | - Ineke Neefs
- Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve, Belgium
| | - Krishna Das
- Freshwater and Oceanic sciences Unit of reSearch (FOCUS), Laboratory of Oceanology, Université de Liège, Allée du 6 août B6C, B-4000 Liège, Belgium
| | - Yvan Larondelle
- Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve, Belgium
| | - Jean-François Rees
- Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve, Belgium
| | - Cathy Debier
- Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve, Belgium.
| | - Benjamin Lemaire
- Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve, Belgium
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15
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Mu X, Chai T, Wang K, Zhu L, Huang Y, Shen G, Li Y, Li X, Wang C. The developmental effect of difenoconazole on zebrafish embryos: A mechanism research. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 212:18-26. [PMID: 26840512 DOI: 10.1016/j.envpol.2016.01.035] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/09/2015] [Accepted: 01/13/2016] [Indexed: 06/05/2023]
Abstract
Difenoconazole is a widely used triazole fungicide and has been reported to have negative impacts on zebrafish embryos. To investigate the mechanism of its developmental toxicity, zebrafish embryos were exposed to 0.5 and 2.0 mg/L difenoconazole for 96 h. The morphological and physiological indicators of embryo development were tested. The total cholesterol (TCHO) level, triglyceride (TG) level and malondialdehyde (MDA) content were measured at 96 hpf (hours post-fertilization). In addition, the transcription of genes related to embryo development, the antioxidant system, lipid synthesis and metabolism was quantified. Our results showed that a large suite of symptoms were induced by difenoconazole, including hatching regression, heart rate decrease, growth inhibition and teratogenic effects. 0.5 mg/L difenoconazole could significantly increase the TG content of zebrafish embryos at 96 hpf, while no apparent change in the TCHO and MDA level was observed post 96 h exposure. Q-PCR (quantitative real-time polymerase chain reaction) results showed that the transcription of genes related to embryonic development was decreased after exposure. Genes related to hatching, retinoic acid metabolism and lipid homeostasis were up-regulated by difenoconazole.
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Affiliation(s)
- Xiyan Mu
- College of Sciences, China Agricultural University, Beijing, PR China; Center of Fishery Resources and Ecology Environment Research, Chinese Academy of Fishery Sciences, Beijing, PR China
| | - Tingting Chai
- College of Sciences, China Agricultural University, Beijing, PR China
| | - Kai Wang
- Plant Protection College, Shenyang Agricultural University, Shenyang, PR China
| | - Lizhen Zhu
- College of Sciences, China Agricultural University, Beijing, PR China
| | - Ying Huang
- Center of Fishery Resources and Ecology Environment Research, Chinese Academy of Fishery Sciences, Beijing, PR China
| | - Gongming Shen
- Center of Fishery Resources and Ecology Environment Research, Chinese Academy of Fishery Sciences, Beijing, PR China
| | - Yingren Li
- Center of Fishery Resources and Ecology Environment Research, Chinese Academy of Fishery Sciences, Beijing, PR China
| | - Xuefeng Li
- College of Sciences, China Agricultural University, Beijing, PR China.
| | - Chengju Wang
- College of Sciences, China Agricultural University, Beijing, PR China.
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16
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Luo X, Bai R, Liu S, Shan C, Chen C, Lan Y. Mechanism of Rhodium-Catalyzed Formyl Activation: A Computational Study. J Org Chem 2016; 81:2320-6. [DOI: 10.1021/acs.joc.5b02828] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaoling Luo
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, People’s Republic of China
| | - Ruopeng Bai
- College
of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, People’s Republic of China
| | - Song Liu
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, People’s Republic of China
| | - Chunhui Shan
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, People’s Republic of China
| | - Changguo Chen
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, People’s Republic of China
| | - Yu Lan
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, People’s Republic of China
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17
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Cytochrome P450 20A1 in zebrafish: Cloning, regulation and potential involvement in hyperactivity disorders. Toxicol Appl Pharmacol 2016; 296:73-84. [PMID: 26853319 DOI: 10.1016/j.taap.2016.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/29/2016] [Accepted: 02/01/2016] [Indexed: 12/17/2022]
Abstract
Cytochrome P450 (CYP) enzymes for which there is no functional information are considered "orphan" CYPs. Previous studies showed that CYP20A1, an orphan, is expressed in human hippocampus and substantia nigra, and in zebrafish (Danio rerio) CYP20A1 maternal transcript occurs in eggs, suggesting involvement in brain and in early development. Moreover, hyperactivity is reported in humans with chromosome 2 microdeletions including CYP20A1. We examined CYP20A1 in zebrafish, including impacts of chemical exposure on expression. Zebrafish CYP20A1 cDNA was cloned, sequenced, and aligned with cloned human CYP20A1 and predicted vertebrate orthologs. CYP20A1s share a highly conserved N-terminal region and unusual sequences in the I-helix and the heme-binding CYP signature motifs. CYP20A1 mRNA expression was observed in adult zebrafish organs including the liver, heart, gonads, spleen and brain, as well as the eye and optic nerve. Putative binding sites in proximal promoter regions of CYP20A1s, and response of zebrafish CYP20A1 to selected nuclear and xenobiotic receptor agonists, point to up-regulation by agents involved in steroid hormone response, cholesterol and lipid metabolism. There also was a dose-dependent reduction of CYP20A1 expression in embryos exposed to environmentally relevant levels of methylmercury. Morpholino knockdown of CYP20A1 in developing zebrafish resulted in behavioral effects, including hyperactivity and a slowing of the optomotor response in larvae. The results suggest that altered expression of CYP20A1 might be part of a mechanism linking methylmercury exposure to neurobehavioral deficits. The expanded information on CYP20A1 brings us closer to "deorphanization", that is, identifying CYP20A1 functions and its roles in health and disease.
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18
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Goldstone JV, Sundaramoorthy M, Zhao B, Waterman MR, Stegeman JJ, Lamb DC. Genetic and structural analyses of cytochrome P450 hydroxylases in sex hormone biosynthesis: Sequential origin and subsequent coevolution. Mol Phylogenet Evol 2016; 94:676-687. [PMID: 26432395 PMCID: PMC4801120 DOI: 10.1016/j.ympev.2015.09.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 07/27/2015] [Accepted: 09/14/2015] [Indexed: 12/14/2022]
Abstract
Biosynthesis of steroid hormones in vertebrates involves three cytochrome P450 hydroxylases, CYP11A1, CYP17A1 and CYP19A1, which catalyze sequential steps in steroidogenesis. These enzymes are conserved in the vertebrates, but their origin and existence in other chordate subphyla (Tunicata and Cephalochordata) have not been clearly established. In this study, selected protein sequences of CYP11A1, CYP17A1 and CYP19A1 were compiled and analyzed using multiple sequence alignment and phylogenetic analysis. Our analyses show that cephalochordates have sequences orthologous to vertebrate CYP11A1, CYP17A1 or CYP19A1, and that echinoderms and hemichordates possess CYP11-like but not CYP19 genes. While the cephalochordate sequences have low identity with the vertebrate sequences, reflecting evolutionary distance, the data show apparent origin of CYP11 prior to the evolution of CYP19 and possibly CYP17, thus indicating a sequential origin of these functionally related steroidogenic CYPs. Co-occurrence of the three CYPs in early chordates suggests that the three genes may have coevolved thereafter, and that functional conservation should be reflected in functionally important residues in the proteins. CYP19A1 has the largest number of conserved residues while CYP11A1 sequences are less conserved. Structural analyses of human CYP11A1, CYP17A1 and CYP19A1 show that critical substrate binding site residues are highly conserved in each enzyme family. The results emphasize that the steroidogenic pathways producing glucocorticoids and reproductive steroids are several hundred million years old and that the catalytic structural elements of the enzymes have been conserved over the same period of time. Analysis of these elements may help to identify when precursor functions linked to these enzymes first arose.
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Affiliation(s)
- Jared V Goldstone
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | | | - Bin Zhao
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Michael R Waterman
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - John J Stegeman
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
| | - David C Lamb
- Institute of Life Science, Medical School, Swansea University, Singleton Park, Swansea SA2 8PP, UK.
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19
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Chen ZF, Ying GG. Occurrence, fate and ecological risk of five typical azole fungicides as therapeutic and personal care products in the environment: A review. ENVIRONMENT INTERNATIONAL 2015; 84:142-153. [PMID: 26277639 DOI: 10.1016/j.envint.2015.07.022] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 07/28/2015] [Accepted: 07/29/2015] [Indexed: 06/04/2023]
Abstract
Azole fungicides are widely used to treat fungal infection in human. After application, these chemicals may reach to the receiving environment via direct or indirect discharge of wastewaters, thus posing potential risks to non-target organisms. We aimed to review the occurrence, fate and toxicological effects of some representative household azole fungicides in the environment. Azole fungicides were widely detected in surface water and sediment of the aquatic environment due to their incomplete removal in wastewater treatment plants. These chemicals are found resistant to microbial degradation, but can undergo photolysis under UV irradiation. Due to different physiochemical properties, azole fungicides showed different environmental behaviors. The residues of azole fungicides could cause toxic effects on aquatic organisms such as algae and fish. The reported effects include regulation changes in expression of cytochrome P450-related genes and alteration in CYP450-regulated steroidogenesis causing endocrine disruption in fish. Further studies are essential to investigate the removal of azole fungicides by advanced treatment technologies, environmental fate such as natural photolysis, and toxic pathways in aquatic organisms.
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Affiliation(s)
- Zhi-Feng Chen
- Ministry of Agriculture Key Laboratory of Tropical & Subtropical Fishery Resources Utilization & Cultivation, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China; State Key Laboratory of Organic Geochemistry, CAS Centre for Pearl River Delta Environmental Pollution and Control Research, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Guang-Guo Ying
- State Key Laboratory of Organic Geochemistry, CAS Centre for Pearl River Delta Environmental Pollution and Control Research, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
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20
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Mu X, Chai T, Wang K, Zhang J, Zhu L, Li X, Wang C. Occurrence and origin of sensitivity toward difenoconazole in zebrafish (Danio reio) during different life stages. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2015; 160:57-68. [PMID: 25621397 DOI: 10.1016/j.aquatox.2015.01.001] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 01/02/2015] [Accepted: 01/03/2015] [Indexed: 06/04/2023]
Abstract
We report here an investigation of the mechanisms contributing to the divergent sensitivity toward the triazole fungicide difenoconazole of zebrafish (Danio reio) during different life stages. Adult and embryonic zebrafish were exposed to three different concentrations of difenoconazole (0.01, 0.5 and 1.0mg/L). The death rate, bioaccumulation of difenoconazole, oxidative stress parameters and transcription of related genes were tested at 4 and 8 days post-exposure (dpe). The death rate for adult zebrafish was much higher than that of the embryos at an exposure concentration of 1.0mg/L at both 4 and 8 dpe. The concentrations of difenoconazole in both the embryos and adult fish were similar, except for the group exposed to 0.01mg/L difenoconazole. A decrease in antioxidant enzyme activities was observed in both the embryos and the livers of adult fish after exposure to difenoconazole. Significant lipid peroxidation was found in the livers of adult fish in all exposure groups at 8 dpe, but was not observed in the treated embryos. The gene transcription response of the embryos toward difenoconazole was different from that in the livers of adult fish at 4 dpe. At 8 dpe, the modification in the transcription of the tested genes in the embryos and adult fish was similar, except for the genes related to the synthesis of sterols.
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Affiliation(s)
- Xiyan Mu
- College of Sciences, China Agricultural University, Beijing 100913, People's Republic of China.
| | - Tingting Chai
- College of Sciences, China Agricultural University, Beijing 100913, People's Republic of China.
| | - Kai Wang
- College of Sciences, China Agricultural University, Beijing 100913, People's Republic of China.
| | - Jie Zhang
- College of Sciences, China Agricultural University, Beijing 100913, People's Republic of China.
| | - Lizhen Zhu
- College of Sciences, China Agricultural University, Beijing 100913, People's Republic of China.
| | - Xuefeng Li
- College of Sciences, China Agricultural University, Beijing 100913, People's Republic of China.
| | - Chengju Wang
- College of Sciences, China Agricultural University, Beijing 100913, People's Republic of China.
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21
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Clotrimazole as a potent agent for treating the oomycete fish pathogen Saprolegnia parasitica through inhibition of sterol 14α-demethylase (CYP51). Appl Environ Microbiol 2014; 80:6154-66. [PMID: 25085484 DOI: 10.1128/aem.01195-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A candidate CYP51 gene encoding sterol 14α-demethylase from the fish oomycete pathogen Saprolegnia parasitica (SpCYP51) was identified based on conserved CYP51 residues among CYPs in the genome. It was heterologously expressed in Escherichia coli, purified, and characterized. Lanosterol, eburicol, and obtusifoliol bound to purified SpCYP51 with similar binding affinities (Ks, 3 to 5 μM). Eight pharmaceutical and six agricultural azole antifungal agents bound tightly to SpCYP51, with posaconazole displaying the highest apparent affinity (Kd, ≤3 nM) and prothioconazole-desthio the lowest (Kd, ∼51 nM). The efficaciousness of azole antifungals as SpCYP51 inhibitors was confirmed by 50% inhibitory concentrations (IC50s) of 0.17 to 2.27 μM using CYP51 reconstitution assays. However, most azole antifungal agents were less effective at inhibiting S. parasitica, Saprolegnia diclina, and Saprolegnia ferax growth. Epoxiconazole, fluconazole, itraconazole, and posaconazole failed to inhibit Saprolegnia growth (MIC100, >256 μg ml(-1)). The remaining azoles inhibited Saprolegnia growth only at elevated concentrations (MIC100 [the lowest antifungal concentration at which growth remained completely inhibited after 72 h at 20°C], 16 to 64 μg ml(-1)) with the exception of clotrimazole, which was as potent as malachite green (MIC100, ∼1 μg ml(-1)). Sterol profiles of azole-treated Saprolegnia species confirmed that endogenous CYP51 enzymes were being inhibited with the accumulation of lanosterol in the sterol fraction. The effectiveness of clotrimazole against SpCYP51 activity (IC50, ∼1 μM) and the concentration inhibiting the growth of Saprolegnia species in vitro (MIC100, ∼1 to 2 μg ml(-1)) suggest that clotrimazole could be used against Saprolegnia infections, including as a preventative measure by pretreatment of fish eggs, and for freshwater-farmed fish as well as in leisure activities.
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22
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Lin CH, Chou PH, Chen PJ. Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish. JOURNAL OF HAZARDOUS MATERIALS 2014; 277:150-158. [PMID: 24962053 DOI: 10.1016/j.jhazmat.2014.05.083] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 05/28/2014] [Accepted: 05/29/2014] [Indexed: 06/03/2023]
Abstract
Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish populations in the aquatic environment.
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Affiliation(s)
- Chun-Hung Lin
- Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan
| | - Pei-Hsin Chou
- Department of Environmental Engineering, National Cheng-Kung University, Tainan, Taiwan
| | - Pei-Jen Chen
- Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan.
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23
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Wang E, Chinni S, Bhore SJ. Three-dimensional (3D) structure prediction of the American and African oil-palms β-ketoacyl-[ACP] synthase-II protein by comparative modelling. Bioinformation 2014; 10:130-7. [PMID: 24748752 PMCID: PMC3974239 DOI: 10.6026/97320630010130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 03/06/2014] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The fatty-acid profile of the vegetable oils determines its properties and nutritional value. Palm-oil obtained from the African oil-palm [Elaeis guineensis Jacq. (Tenera)] contains 44% palmitic acid (C16:0), but, palm-oil obtained from the American oilpalm [Elaeis oleifera] contains only 25% C16:0. In part, the b-ketoacyl-[ACP] synthase II (KASII) [EC: 2.3.1.179] protein is responsible for the high level of C16:0 in palm-oil derived from the African oil-palm. To understand more about E. guineensis KASII (EgKASII) and E. oleifera KASII (EoKASII) proteins, it is essential to know its structures. Hence, this study was undertaken. OBJECTIVE The objective of this study was to predict three-dimensional (3D) structure of EgKASII and EoKASII proteins using molecular modelling tools. MATERIALS AND METHODS The amino-acid sequences for KASII proteins were retrieved from the protein database of National Center for Biotechnology Information (NCBI), USA. The 3D structures were predicted for both proteins using homology modelling and ab-initio technique approach of protein structure prediction. The molecular dynamics (MD) simulation was performed to refine the predicted structures. The predicted structure models were evaluated and root mean square deviation (RMSD) and root mean square fluctuation (RMSF) values were calculated. RESULTS The homology modelling showed that EgKASII and EoKASII proteins are 78% and 74% similar with Streptococcus pneumonia KASII and Brucella melitensis KASII, respectively. The EgKASII and EoKASII structures predicted by using ab-initio technique approach shows 6% and 9% deviation to its structures predicted by homology modelling, respectively. The structure refinement and validation confirmed that the predicted structures are accurate. CONCLUSION The 3D structures for EgKASII and EoKASII proteins were predicted. However, further research is essential to understand the interaction of EgKASII and EoKASII proteins with its substrates.
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Affiliation(s)
- Edina Wang
- Department of Biotechnology, Faculty of Applied Sciences, AIMST University, Bedong-Semeling Road, Bedong, 08100, Kedah, Malaysia
| | - Suresh Chinni
- Department of Biotechnology, Faculty of Applied Sciences, AIMST University, Bedong-Semeling Road, Bedong, 08100, Kedah, Malaysia
| | - Subhash Janardhan Bhore
- Department of Biotechnology, Faculty of Applied Sciences, AIMST University, Bedong-Semeling Road, Bedong, 08100, Kedah, Malaysia
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