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Durand E, Chantreau M, Le Veve A, Stetsenko R, Dubin M, Genete M, Llaurens V, Poux C, Roux C, Billiard S, Vekemans X, Castric V. Evolution of self-incompatibility in the Brassicaceae: Lessons from a textbook example of natural selection. Evol Appl 2020; 13:1279-1297. [PMID: 32684959 PMCID: PMC7359833 DOI: 10.1111/eva.12933] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/25/2020] [Accepted: 01/29/2020] [Indexed: 12/14/2022] Open
Abstract
Self-incompatibility (SI) is a self-recognition genetic system enforcing outcrossing in hermaphroditic flowering plants and results in one of the arguably best understood forms of natural (balancing) selection maintaining genetic variation over long evolutionary times. A rich theoretical and empirical population genetics literature has considerably clarified how the distribution of SI phenotypes translates into fitness differences among individuals by a combination of inbreeding avoidance and rare-allele advantage. At the same time, the molecular mechanisms by which self-pollen is specifically recognized and rejected have been described in exquisite details in several model organisms, such that the genotype-to-phenotype map is also pretty well understood, notably in the Brassicaceae. Here, we review recent advances in these two fronts and illustrate how the joint availability of detailed characterization of genotype-to-phenotype and phenotype-to-fitness maps on a single genetic system (plant self-incompatibility) provides the opportunity to understand the evolutionary process in a unique perspective, bringing novel insight on general questions about the emergence, maintenance, and diversification of a complex genetic system.
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Affiliation(s)
| | | | - Audrey Le Veve
- CNRSUniv. LilleUMR 8198 ‐ Evo‐Eco‐PaleoF-59000 LilleFrance
| | | | - Manu Dubin
- CNRSUniv. LilleUMR 8198 ‐ Evo‐Eco‐PaleoF-59000 LilleFrance
| | - Mathieu Genete
- CNRSUniv. LilleUMR 8198 ‐ Evo‐Eco‐PaleoF-59000 LilleFrance
| | - Violaine Llaurens
- Institut de Systématique, Evolution et Biodiversité (ISYEB)Muséum national d'Histoire naturelleCNRS, Sorbonne Université, EPHE, Université des Antilles CP 5057 rue Cuvier, 75005 ParisFrance
| | - Céline Poux
- CNRSUniv. LilleUMR 8198 ‐ Evo‐Eco‐PaleoF-59000 LilleFrance
| | - Camille Roux
- CNRSUniv. LilleUMR 8198 ‐ Evo‐Eco‐PaleoF-59000 LilleFrance
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2
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Lynch C, Dubin M, Gunning F, Liston C. Response to rTMS in patients with medication-resistant depression is linked with the functional brain network affiliation of the stimulation site. Brain Stimul 2019. [DOI: 10.1016/j.brs.2018.12.690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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3
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Deng ZD, Davis S, Asturias G, Glidewell M, Liston C, Dubin M. P273 Effect of repetitive transcranial magnetic stimulation on the structural connectome in patients with major depression. Clin Neurophysiol 2017. [DOI: 10.1016/j.clinph.2016.10.382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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4
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Kawakatsu T, Huang SSC, Jupe F, Sasaki E, Schmitz RJ, Urich MA, Castanon R, Nery JR, Barragan C, He Y, Chen H, Dubin M, Lee CR, Wang C, Bemm F, Becker C, O'Neil R, O'Malley RC, Quarless DX, Schork NJ, Weigel D, Nordborg M, Ecker JR. Epigenomic Diversity in a Global Collection of Arabidopsis thaliana Accessions. Cell 2017; 166:492-505. [PMID: 27419873 PMCID: PMC5172462 DOI: 10.1016/j.cell.2016.06.044] [Citation(s) in RCA: 409] [Impact Index Per Article: 58.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 06/22/2016] [Accepted: 06/24/2016] [Indexed: 12/15/2022]
Abstract
The epigenome orchestrates genome accessibility, functionality, and three-dimensional structure. Because epigenetic variation can impact transcription and thus phenotypes, it may contribute to adaptation. Here, we report 1,107 high-quality single-base resolution methylomes and 1,203 transcriptomes from the 1001 Genomes collection of Arabidopsis thaliana. Although the genetic basis of methylation variation is highly complex, geographic origin is a major predictor of genome-wide DNA methylation levels and of altered gene expression caused by epialleles. Comparison to cistrome and epicistrome datasets identifies associations between transcription factor binding sites, methylation, nucleotide variation, and co-expression modules. Physical maps for nine of the most diverse genomes reveal how transposons and other structural variants shape the epigenome, with dramatic effects on immunity genes. The 1001 Epigenomes Project provides a comprehensive resource for understanding how variation in DNA methylation contributes to molecular and non-molecular phenotypes in natural populations of the most studied model plant.
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Affiliation(s)
- Taiji Kawakatsu
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Genetically Modified Organism Research Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
| | - Shao-Shan Carol Huang
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Florian Jupe
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Eriko Sasaki
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter, 1030 Vienna, Austria
| | - Robert J Schmitz
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Mark A Urich
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Rosa Castanon
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Joseph R Nery
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Cesar Barragan
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Yupeng He
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Huaming Chen
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Manu Dubin
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter, 1030 Vienna, Austria
| | - Cheng-Ruei Lee
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter, 1030 Vienna, Austria
| | - Congmao Wang
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany; Institute of Digital Agriculture, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, 310021, PR China
| | - Felix Bemm
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Claude Becker
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Ryan O'Neil
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Ronan C O'Malley
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | | | | | | | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Magnus Nordborg
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter, 1030 Vienna, Austria
| | - Joseph R Ecker
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
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5
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Małolepszy A, Mun T, Sandal N, Gupta V, Dubin M, Urbański D, Shah N, Bachmann A, Fukai E, Hirakawa H, Tabata S, Nadzieja M, Markmann K, Su J, Umehara Y, Soyano T, Miyahara A, Sato S, Hayashi M, Stougaard J, Andersen SU. The LORE1 insertion mutant resource. Plant J 2016; 88:306-317. [PMID: 27322352 DOI: 10.1111/tpj.13243] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/07/2016] [Accepted: 06/10/2016] [Indexed: 05/08/2023]
Abstract
Long terminal repeat (LTR) retrotransposons are closely related to retroviruses, and their activities shape eukaryotic genomes. Here, we present a complete Lotus japonicus insertion mutant collection generated by identification of 640 653 new insertion events following de novo activation of the LTR element Lotus retrotransposon 1 (LORE1) (http://lotus.au.dk). Insertion preferences are critical for effective gene targeting, and we exploit our large dataset to analyse LTR element characteristics in this context. We infer the mechanism that generates the consensus palindromes typical of retroviral and LTR retrotransposon insertion sites, identify a short relaxed insertion site motif, and demonstrate selective integration into CHG-hypomethylated genes. These characteristics result in a steep increase in deleterious mutation rate following activation, and allow LORE1 active gene targeting to approach saturation within a population of 134 682 L. japonicus lines. We suggest that saturation mutagenesis using endogenous LTR retrotransposons with germinal activity can be used as a general and cost-efficient strategy for generation of non-transgenic mutant collections for unrestricted use in plant research.
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Affiliation(s)
- Anna Małolepszy
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Terry Mun
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Niels Sandal
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Vikas Gupta
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Manu Dubin
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030, Vienna, Austria
| | - Dorian Urbański
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Niraj Shah
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Asger Bachmann
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Eigo Fukai
- Division of Plant Sciences, National Institute of Agrobiological Sciences (NIAS), 2-1-2 Kannon-dai, Tsukuba, 305-8602, Japan
| | - Hideki Hirakawa
- Kazusa DNA Research Institute, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba, 292-0818, Japan
| | - Satoshi Tabata
- Kazusa DNA Research Institute, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba, 292-0818, Japan
| | - Marcin Nadzieja
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Katharina Markmann
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Junyi Su
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Yosuke Umehara
- Division of Plant Sciences, National Institute of Agrobiological Sciences (NIAS), 2-1-2 Kannon-dai, Tsukuba, 305-8602, Japan
| | - Takashi Soyano
- Division of Plant Sciences, National Institute of Agrobiological Sciences (NIAS), 2-1-2 Kannon-dai, Tsukuba, 305-8602, Japan
| | - Akira Miyahara
- Division of Plant Sciences, National Institute of Agrobiological Sciences (NIAS), 2-1-2 Kannon-dai, Tsukuba, 305-8602, Japan
| | - Shusei Sato
- Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan
| | - Makoto Hayashi
- Division of Plant Sciences, National Institute of Agrobiological Sciences (NIAS), 2-1-2 Kannon-dai, Tsukuba, 305-8602, Japan
| | - Jens Stougaard
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
| | - Stig U Andersen
- Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000, Aarhus C, Denmark
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Villamil SHF, Dubin M, Portela MPM, Perissinotti LJ, Brusa MA, Stoppani AOM. Semiquinone production by lipophilico-naphthoquinones. Redox Rep 2016; 3:245-52. [DOI: 10.1080/13510002.1997.11747117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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7
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Dinh HQ, Dubin M, Sedlazeck FJ, Lettner N, Mittelsten Scheid O, von Haeseler A. Advanced methylome analysis after bisulfite deep sequencing: an example in Arabidopsis. PLoS One 2012; 7:e41528. [PMID: 22911809 PMCID: PMC3401099 DOI: 10.1371/journal.pone.0041528] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 06/27/2012] [Indexed: 11/18/2022] Open
Abstract
Deep sequencing after bisulfite conversion (BS-Seq) is the method of choice to generate whole genome maps of cytosine methylation at single base-pair resolution. Its application to genomic DNA of Arabidopsis flower bud tissue resulted in the first complete methylome, determining a methylation rate of 6.7% in this tissue. BS-Seq reads were mapped onto an in silico converted reference genome, applying the so-called 3-letter genome method. Here, we present BiSS (Bisufite Sequencing Scorer), a new method applying Smith-Waterman alignment to map bisulfite-converted reads to a reference genome. In addition, we introduce a comprehensive adaptive error estimate that accounts for sequencing errors, erroneous bisulfite conversion and also wrongly mapped reads. The re-analysis of the Arabidopsis methylome data with BiSS mapped substantially more reads to the genome. As a result, it determines the methylation status of an extra 10% of cytosines and estimates the methylation rate to be 7.7%. We validated the results by individual traditional bisulfite sequencing for selected genomic regions. In addition to predicting the methylation status of each cytosine, BiSS also provides an estimate of the methylation degree at each genomic site. Thus, BiSS explores BS-Seq data more extensively and provides more information for downstream analysis.
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Affiliation(s)
- Huy Q. Dinh
- Max F. Perutz Laboratories, Center for Integrative Bioinformatics Vienna, University of Vienna and Medical University Vienna, Vienna, Austria
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna, Austria
| | - Manu Dubin
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna, Austria
| | - Fritz J. Sedlazeck
- Max F. Perutz Laboratories, Center for Integrative Bioinformatics Vienna, University of Vienna and Medical University Vienna, Vienna, Austria
| | - Nicole Lettner
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna, Austria
| | - Ortrun Mittelsten Scheid
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna, Austria
- * E-mail: (OMS); or (AvH)
| | - Arndt von Haeseler
- Max F. Perutz Laboratories, Center for Integrative Bioinformatics Vienna, University of Vienna and Medical University Vienna, Vienna, Austria
- * E-mail: (OMS); or (AvH)
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8
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Dubin M, Fuchs J, Gräf R, Schubert I, Nellen W. Dynamics of a novel centromeric histone variant CenH3 reveals the evolutionary ancestral timing of centromere biogenesis. Nucleic Acids Res 2010; 38:7526-37. [PMID: 20675719 PMCID: PMC2995078 DOI: 10.1093/nar/gkq664] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The centromeric histone H3 variant (CenH3) serves to target the kinetochore to the centromeres and thus ensures correct chromosome segregation during mitosis and meiosis. The Dictyostelium H3-like variant H3v1 was identified as the CenH3 ortholog. Dictyostelium CenH3 has an extended N-terminal domain with no similarity to any other known proteins and a histone fold domain at its C-terminus. Within the histone fold, α-helix 2 (α2) and an extended loop 1 (L1) have been shown to be required for targeting CenH3 to centromeres. Compared to other known and putative CenH3 histones, Dictyostelium CenH3 has a shorter L1, suggesting that the extension is not an obligatory feature. Through ChIP analysis and fluorescence microscopy of live and fixed cells, we provide here the first survey of centromere structure in amoebozoa. The six telocentric centromeres were found to mostly consist of all the DIRS-1 elements and to associate with H3K9me3. During interphase, the centromeres remain attached to the centrosome forming a single CenH3-containing cluster. Loading of Dictyostelium CenH3 onto centromeres occurs at the G2/prophase transition, in contrast to the anaphase/telophase loading of CenH3 observed in metazoans. This suggests that loading during G2/prophase is the ancestral eukaryotic mechanism and that anaphase/telophase loading of CenH3 has evolved more recently after the amoebozoa diverged from the animal linage.
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Affiliation(s)
- Manu Dubin
- Department of Genetics, University Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany
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9
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Dubin M, Nellen W. A versatile set of tagged expression vectors to monitor protein localisation and function in Dictyostelium. Gene 2010; 465:1-8. [PMID: 20600701 DOI: 10.1016/j.gene.2010.06.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2010] [Revised: 06/13/2010] [Accepted: 06/22/2010] [Indexed: 11/29/2022]
Abstract
We describe here a series of vectors for ectopic expression of tagged proteins in Dictyostelium discoideum. These vectors allow the addition of N- or C-terminal tags (GFP, mRFP, 3xFLAG, 3xHA, 6xMYC or TAP) with an optimised polylinker sequence and no additional amino acid residues at the N- or C-terminus of the protein. The expression cassettes were introduced into vectors containing Blasticidin or Geneticin resistance markers and into integrating as well as extrachromosomal plasmids. The vectors are designed as high and low copy versions and thus allow for a limited expression level control. They are also convenient with regard to complementation, co- and super-transformation. Finally the vectors share standardised cloning sites, so that a gene of interest can be easily transferred between vectors as experimental requirements evolve. These vectors were used to study the localisation of several putative RNA processing proteins including EriA and DicerB.
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Affiliation(s)
- Manu Dubin
- Department of Genetics, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany.
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10
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Paulino M, Alvareda E, Denis P, Barreiro E, Sperandio da Silva G, Dubin M, Gastellú C, Aguilera S, Tapia O. Studies of trypanocidal (inhibitory) power of naphthoquinones: Evaluation of quantum chemical molecular descriptors for structure–activity relationships. Eur J Med Chem 2008; 43:2238-46. [DOI: 10.1016/j.ejmech.2007.12.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 12/12/2007] [Accepted: 12/12/2007] [Indexed: 11/28/2022]
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Abstract
The review presents: a) a brief description of the disease; b) a summary of the most important metabolic targets so far identified in Trypanosome cruzi (T. cruzi) along with corresponding inhibitor compounds; c) the current state of knowledge on the trypanothione reductase system of trypanosomatids with reference to oxidative stress defenses; d) detailed discussions on T. cruzi trypanothione reductase inhibitors such as nitrofuranes, naphthoquinones and phenothiazines. As yet, the chemotherapy of Chagas' disease remains an unsolved problem. Further search for new drugs must continue by means of nucleating existing chemotherapy efforts.
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Affiliation(s)
- M Paulino
- Departamento de Químico-Física y Matemáticas, Facultad de Química, Universidad de la Republica. Gral. Flores, 2124, 11800 Montevideo, Uruguay.
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12
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Lambert I, Debiec-Rychter M, Dubin M, Sciot R. Solid alveolar rhabdomyosarcoma originating from the urinary bladder in an adult. Diagnostic value of molecular genetics. Histopathology 2004; 44:508-10. [PMID: 15140004 DOI: 10.1111/j.1365-2559.2004.01830.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Dubin M, Fernandez Villamil SH, Stoppani AO. [Cytotoxicity of beta-lapachone, an naphthoquinone with possible therapeutic use]. Medicina (B Aires) 2001; 61:343-50. [PMID: 11474885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
beta-lapachone (beta-lap) is a lipophilic o-naphthoquinone isolated from the bark of the lapacho tree. Initial observations proved its capability for inhibiting growth of Yoshida tumor and Walker 256 carcinosarcoma. beta-Lap redox-cycling in the presence of reductants and oxygen yields "reactive oxygen species" (ROS: O2-, OH and H2O2) which cytotoxicity led to assume its role in beta-lap activity in cells. beta-Lap inhibited DNA synthesis in Trypanosoma cruzi as well as topoisomerases I and II, poly(ADP-ribose) polymerase (PARP) in different cells. These enzymes are essential for maintaining DNA structure. beta-Lap inhibited growth of a large variety of tumor cells including epidermoid laringeal cancer, prostate, colon, ovary and breast cancer and also different types of leukemia cells. Advances in knowledge of apoptosis ("programmed cell death") and necrosis provided useful information for understanding the mechanism of beta-lap cytotoxicity. Thiol-dependent proteases (Calpaine), kinases (e.g. c-JUN NH2-terminal kinase), caspases and nucleases are involved in beta-lap cytotoxicity. These enzymes activity, as well as ROS production by beta-lap redox-cycling, would be essential for beta-lap cytotoxicity. Diaphorase and NAD(P)H-quinone reductase, which catalyse beta-lap redox-cycling and ROS production, seem to play an essential role in beta-lap activity. On these grounds, clinical applications of beta-lap have been suggested.
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Affiliation(s)
- M Dubin
- Centro de Investigaciones Bioenergéticas, Facultad de Medicina (UBA-CONICET), Universidad de Buenos Aires
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Buchman AL, Ament ME, Sohel M, Dubin M, Jenden DJ, Roch M, Pownall H, Farley W, Awal M, Ahn C. Choline deficiency causes reversible hepatic abnormalities in patients receiving parenteral nutrition: proof of a human choline requirement: a placebo-controlled trial. JPEN J Parenter Enteral Nutr 2001; 25:260-8. [PMID: 11531217 DOI: 10.1177/0148607101025005260] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Previous studies have shown that plasma free choline concentrations are significantly decreased in many long-term home total parenteral nutrition (TPN) patients. Furthermore, low choline status has been associated with both hepatic morphologic and hepatic aminotransferase abnormalities. A preliminary pilot study suggested choline-supplemented TPN may be useful in reversal of these hepatic abnormalities. METHODS Fifteen patients (10 M, 5 F) who had required TPN for > or =80% of their nutritional needs were randomized to receive their usual TPN (n = 8), or TPN to which 2 g choline chloride had been added (n = 7) for 24 weeks. Baseline demographic data were similar between groups. Patients had CT scans of the liver and spleen, and blood for plasma free and phospholipid-bound choline, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, gamma glutamyl transferase (GGT), bilirubin, serum lipids, complete blood count (CBC), and chemistry profile obtained at baseline, and weeks 2, 4, 6, 12, 16, 20, 24, and 34. CT scans were analyzed for Hounsfield unit (HU) densities. RESULTS There were no significant differences in any measured parameters after 2 weeks. However, at 4 weeks, a significant difference in liver HU between groups was observed (13.3+/-5.0 HU [choline] vs 5.8+/-5.2 HU [placebo], p = .04). This significant trend continued through week 24. Recurrent hepatic steatosis and decreased HU were observed at week 34, 10 weeks after choline supplementation had been discontinued. A significant increase in the liver-spleen differential HU was also observed in the choline group (10.6+/-6.2 HU [choline] vs 1.3+/-3.3 HU [placebo], p = .01). Serum ALT decreased significantly (p = .01 to .05) in the choline group vs placebo at weeks 6,12, 20, and 24. Serum AST was significantly decreased in the choline group by week 24 (p = .02). The serum alkaline phosphatase was significantly reduced in the choline group at weeks 2, 12, 20, 24, and 34 (p = .02 to 0.07). Total bilirubin was normal in these patients and remained unchanged during the study. Serum GGT tended to decrease more in the choline group, but the greater decrease was not statistically significant. CONCLUSIONS Choline deficiency is a significant contributor to the development of TPN-associated liver disease. The data suggest choline is a required nutrient for long-term home TPN patients.
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Affiliation(s)
- A L Buchman
- Division of Gastroenterology, Northwestern University Medical School, Chicago, IL 60611, USA.
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15
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Dubin M, Stoppani AO. [Programmed cell death and apoptosis. The role of mitochondria]. Medicina (B Aires) 2001; 60:375-86. [PMID: 11050822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
Physiological cell death and apoptosis are natural processes genetically programmed, subjected to control by complex molecular mechanisms which elucidation is of particular interest for biology and medicine. Mitochondria play an essential role in physiological cell death and apoptosis. Apoptogenic effects develop in three phases, namely: (a) premitochondrial; (b) mitochondrial and (c) post-mitochondrial. During the first phase, apoptogenic signals (genotoxic agents, oxygen free radicals, corticoids, antibodies, etc.) interact with cell receptors activating specific mechanisms including thiol dependent proteases (caspases). As a consequence of those signals, mitochondrial damage results (membrane permeabilization, collapse of the membrane potential, swelling, membrane disruption, inhibition of electron transfer and oxidative phosphorylation). Other consequences of the mitochondrial disruption are the enhancement of free radical production and the exit of cytochrome c, caspases and endonucleases to the cytosol. During the third phase of apoptosis, free radicals and activated enzymes attack the cell protein structure and ADN, thus causing cell death. The mitochondrial regulation of apoptosis is controlled by the mitochondrial transitory permeability pore (MTPP) which is constituted by caspases, hexokinases, cytochrome c, ATP and ADP. MTPP is subjected to control by apoptogenic or antiapoptogenic agents which open or close it, according to their structure and the cell metabolic conditions. Uncontrolled opening of MTPP determines a massive exit of mitochondrial apoptogenic factors which in the cytosol and the nucleus exert their apoptogenic effects, thus producing cell death. MTPP can be modified by drugs with potential therapeutic actions thus opening interesting therapeutic possibilities. The role of apoptosis in pathologies such as degenerative diseases of the nervous system, autoimmunity diseases, SIDA and cancer is discussed.
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Affiliation(s)
- M Dubin
- Centro de Investigaciones Bioenergéticas, Facultad de Medicina (UBA-CONICET), Universidad de Buenos Aires
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16
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Van den Bosch T, Dubin M, Cornelis A. Favorable pregnancy outcome in a woman with osseous metaplasia of the uterus. Ultrasound Obstet Gynecol 2000; 15:445-446. [PMID: 10976492 DOI: 10.1046/j.1469-0705.2000.00105.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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17
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Abstract
A case of a subamniotic hematoma was diagnosed at 34 weeks of gestation. Pregnancy and delivery were uneventful. The ultrasound features of a subamniotic hematoma, and the differential diagnosis with lesions of less favorable outcome are described.
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Affiliation(s)
- T Van Den Bosch
- Department of Obstetrics and Gynecology, A.Z. Heilig Hart, Tienen, Belgium
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18
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Carrizo PH, Dubin M, Stoppani AO. [Physiopathologic effects of nitric oxide and their relationship with oxidative stress]. Medicina (B Aires) 1998; 58:367-73. [PMID: 9816698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Nitric oxide (NO.) is produced from L-arginine, as result of a reaction catalyzed by the enzyme nitric oxide synthase (NOS). The reaction is the sole source of NO. in animal tissues. NO. can control physiological processes (or systems) such as (a) blood pressure; (b) relaxation of arterial smooth muscle; (c) platelet aggregation and adhesion; (d) neurotransmission; (e) neuroendocrine secretion. NO. contributes to the killing of pathogenic microorganisms and tumoral cells by phagocytes. NO. reacts with superoxide anion thus producing peroxynitrite, a cytotoxic ion capable of destroying many biological targets. The superoxide/peroxinitrite balance determines the ONOO- production and, accordingly, is essential for the development of hypertension, atherosclerosis, neurodegenerative diseases, viral infections, ischemia-reperfusion injury, and cancer.
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Affiliation(s)
- P H Carrizo
- Centro de Investigaciones Bioenergéticas, Facultad de Medicina, CONICET, Universidad de Buenos Aires, Argentina
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19
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Dubin M, Carrizo PH, Biscardi AM, Fernandez Villamil SH, Stoppani AO. Effect of 5-nitroindole on adenylate energy charge, oxidative phosphorylation, and lipid peroxidation in rat hepatocytes. Biochem Pharmacol 1994; 48:1483-92. [PMID: 7945449 DOI: 10.1016/0006-2952(94)90574-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [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: 01/28/2023]
Abstract
5-Nitroindole (NI), a mutagenic nitroarene, was assayed for cytotoxic effects on rat hepatocytes. After incubation with 25-100 microM NI, the adenylate energy charge of the hepatocytes decreased significantly as a result of the decrease in ATP and the increase in AMP. ATP depletion correlated well with the effects of NI on mitochondrial electron transfer and energy transduction in hepatocytes. Thus, NI (a) inhibited the antimycin-sensitive hepatocyte respiration; (b) inhibited NADH oxidation by disrupted hepatocyte mitochondria; (c) inhibited L-malate-L-glutamate oxidation by ADP-supplemented mitochondria; (d) in the absence of ADP, stimulated the same substrates and also succinate oxidation by mitochondria; (e) released the latent ATPase activity of mitochondrial F1F0-ATP synthase; (f) shifted the redox level of reduced cytochromes (c + c1) and b towards the oxidized state; (g) inhibited NADH oxidation by disrupted mitochondria in the vicinity of the NADH-dehydrogenase flavoprotein; (h) inhibited Ca2+ uptake by mitochondria using L-malate-L-glutamate as an energy source; (i) inhibited valinomycin-induced, endogenously energized K+ uptake, with little effect on the ATP-induced uptake; and (j) inhibited the MgATP-dependent contraction of Ca(2+)-swollen mitochondria. NI inhibited lipid peroxidation in hepatocytes and also in substrate-supplemented liver microsomes and mitochondria, thus ruling out hydroperoxides as a cause of NI cytotoxicity. Long-term incubation with NI produced loss of hepatocyte viability, as indicated by lactate dehydrogenase leakage.
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Affiliation(s)
- M Dubin
- Centro de Investigaciones Bioenergéticas, Facultad de Medicina, Paraguay, Buenos Aires, Argentina
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20
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Buchman AL, Dubin M, Jenden D, Moukarzel A, Roch MH, Rice K, Gornbein J, Ament ME, Eckhert CD. Lecithin increases plasma free choline and decreases hepatic steatosis in long-term total parenteral nutrition patients. Gastroenterology 1992; 102:1363-70. [PMID: 1551541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Plasma-free choline levels have previously been found below normal in patients receiving long term parenteral nutrition (TPN). In a group of 15 patients receiving home TPN who had low plasma free choline levels (6.3 +/- 0.8 mmol/L), we found 50% had hepatic steatosis. These patients were given oral lecithin or placebo in a double-blind randomized trial for 6 weeks. Lecithin supplementation led to an increase in plasma free choline of 53.4% +/- 15.4% at 2 weeks (P = 0.04), which continued at 6 weeks. The placebo group had no change in plasma-free choline at 2 weeks, but a significant decrease of 25.4% +/- 7.1% (P = 0.01) at 6 weeks. A significant and progressive decrease in hepatic fat was indicated by increased liver-spleen CT Hounsfield units at 2 and 6 weeks (7.5 +/- 1.7 units, P = 0.02; 13.8 +/- 3.5 units, P = 0.03) in the lecithin supplemental group. Nonsignificant changes were seen in the placebo group. It was concluded that hepatic steatosis in many patients receiving long term TPN is caused by plasma-free choline deficiency and may be reversed with lecithin supplementation. Choline is a conditionally essential nutrient in this population.
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Affiliation(s)
- A L Buchman
- Division of Pediatric Gastroenterology and Nutrition, UCLA Medical Center
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21
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Dubin M, Fernandez Villamil SH, Paulino de Blumenfeld M, Stoppani AO. Inhibition of microsomal lipid peroxidation and cytochrome P-450-catalyzed reactions by nitrofuran compounds. Free Radic Res Commun 1991; 14:419-31. [PMID: 1663909 DOI: 10.3109/10715769109093430] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
(5-Nitro-2-furfurylidene)amino compounds bearing triazol-4-yl, benzimidazol-1-yl, pyrazol-1-yl, triazin-4-yl or related groups (a) stimulated superoxide anion radical generated by rat liver microsomes in the presence of NADPH and oxygen; (b) inhibited the NADPH-dependent, iron-catalyzed microsomal lipid peroxidation; (c) prevented the NADPH-dependent destruction of cytochrome P-450; (d) inhibited the NADPH-dependent microsomal aniline 4-hydroxylase activity; (e) failed to inhibit either the cumenyl hydroperoxide-dependent lipid peroxidation or the aniline-4-hydroxylase activity, except for the benzimidazol-1-yl and the substituted triazol-4-yl derivatives, which produced minor inhibitions. Reducing equivalents enhanced the benzimidazol-1-yl derivative inhibition of the cumenyl hydroperoxide-induced lipid peroxidation. The ESR spectrum of the benzimidazol-1-yl derivative, reduced anaerobically by NADPH-supplemented microsomes, showed characteristic spin couplings. Compounds bearing unsaturated nitrogen heterocycles were always more active than those bearing other groups, such as nifurtimox or nitrofurazone. The energy level of the lowest unoccupied molecular orbital was in fair agreement with the capability of nitrofurans for redox-cycling and related actions. It is concluded that nitrofuran inhibition of microsomal lipid peroxidation and cytochrome P-450-catalyzed reactions was mostly due to diversion of reducing equivalents from NADPH to dioxygen. Trapping of free radicals involved in propagating lipid peroxidation might contribute to the overall effect of the benzimidazol-1-yl and substituted triazol-4-yl derivatives.
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Affiliation(s)
- M Dubin
- Centro de Investigaciones Bioenergéticas, Facultad de Medicina, Universidad de Buenos Aires, Argentina
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22
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Villamil SF, Dubin M, Galeffi C, Stoppani AO. Effects of mansonones on lipid peroxidation, P450 monooxygenase activity, and superoxide anion generation by rat liver microsomes. Biochem Pharmacol 1990; 40:2343-51. [PMID: 2173928 DOI: 10.1016/0006-2952(90)90732-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [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: 12/30/2022]
Abstract
Several structurally related ortho-naphthoquinones isolated from Mansonia altissima Chev (mansonones C, E and F) (a) inhibited NADPH-dependent, iron-catalyzed microsomal lipid peroxidation; (b) prevented NADPH-dependent cytochrome P450 destruction; (c) inhibited NADPH-supported aniline 4-hydroxylase activity; (d) inhibited Fe(III)ADP reduction by NADPH-supplemented microsomes; (e) stimulated superoxide anion generation by NADPH-supplemented microsomes; and (f) stimulated ascorbate oxidation. ESR investigation of ascorbate-reduced mansonone F demonstrated semiquinone formation. Mansonone C had a greater effect than mansonones E and F on NADPH-dependent lipid peroxidation, O2- production and ascorbate oxidation, whereas mansonone E was more effective than mansonones C and F on aniline 4-hydroxylase activity. Mansonones E and F did not inhibit hydroperoxide-dependent lipid peroxidation, cytochrome P450 destruction or microsomal aniline 4-hydroxylase activity. Mansonone C inhibited to a limited degree tert-butyl hydroperoxide-dependent lipid peroxidation, this inhibition being increased by NADPH. Mansonone A, a tetrahydro orthonapthoquinone derivative, was in all respects relatively less effective than mansonones C, E and F. It is postulated that mansonones C, E and F inhibited microsomal lipid peroxidation and cytochrome P450 catalyzed reactions by diverting reducing equivalents from NADPH to dioxygen, but mansonone C (including its reduced form) may also exert direct antioxidant activity.
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Affiliation(s)
- S F Villamil
- Centro de Investigaciones Bioenergéticas, Facultad de Medicina, Universidad de Buenos Aires, Argentina
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23
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Dubin M, Fernandez Villamil SH, Stoppani AO. Inhibition of microsomal lipid peroxidation and cytochrome P-450-catalyzed reactions by beta-lapachone and related naphthoquinones. Biochem Pharmacol 1990; 39:1151-60. [PMID: 2157443 DOI: 10.1016/0006-2952(90)90256-k] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [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: 12/30/2022]
Abstract
The lipophilic o-naphthoquinones beta-lapachone, 3,4-dihydro-2-methyl-2-ethyl-2H-naphtho[1,2b]pyran-5,6-dione (CG 8-935), 3,4-dihydro-2-methyl-2-phenyl-2H-naphtho[1,2b]pyran-5,6-dione (CG 9-442), and 3,4-dihydro-2,2-dimethyl-9-chloro-2H-naphtho[1,2b]pyran-5,6-dione (CG 10-248) (a) inhibited NADPH-dependent, iron-catalyzed microsomal lipid peroxidation; (b) prevented NADPH-dependent cytochrome P-450 destruction; (c) inhibited microsomal aniline 4-hydroxylase, aminopyrine N-demethylase and 7-ethoxycoumarin deethylase; (d) did not inhibit the ascorbate- and tert-butyl hydroperoxide-dependent lipid peroxidation and the cumenyl hydroperoxide-linked aniline 4-hydroxylase reaction; and (e) stimulated NADPH oxidation, superoxide anion radical generation and Fe(III)ADP reduction by NADPH-supplemented microsomes. In the presence of ascorbate, the same o-naphthoquinones stimulated oxygen uptake and semiquinone formation, as detected by ESR measurements. The p-naphthoquinones alpha-lapachone and menadione were relatively less effective than the o-naphthoquinones. These observations support the hypothesis that, in the micromolar concentration range, o-naphthoquinones inhibit microsomal lipid peroxidation and cytochrome P-450-catalyzed reactions, by diverting reducing equivalents from NADPH to dioxygen.
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Affiliation(s)
- M Dubin
- Centro de Investigaciones Bioenergéticas, Facultad de Medicina, Universidad de Buenos Aires, Argentina
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24
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Fernandez Villamil SH, Dubin M, Brusa MA, Duran RP, Perissinotti LJ, Stoppani AO. Generation of radical anions of nifurtimox and related nitrofuran compounds by ascorbate. Free Radic Res Commun 1990; 10:351-60. [PMID: 2175283 DOI: 10.3109/10715769009149904] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Nifurtimox analogues bearing triazol-4-yl, benzimidazol-1-yl, triazin-4-yl or related groups as counterpart of the (5-nitro-2-furfurylidene) amino group were reduced to their nitro anion radicals by ascorbate in anaerobic solutions at high pH. The ESR spectra of the radical anions showed hyperfine spin couplings restricted to the nitrofuran moiety. With these compounds, the spin density at the nitro group was greater than with nifurtimox, nitrofurazone and nitrofurantoin. At neutral pH, solutions containing ascorbate and nitrofuran derivatives consumed oxygen, the compounds bearing unsaturated nitrogen heterocycles being the most effective. Superoxide dismutase and catalase decreased the rate of oxygen consumption, thus demonstrating the production of superoxide and hydrogen peroxide, respectively. NMR spectra of the triazol-4-yl and triazin-4-yl nitrofuran derivatives showed a deshielding effect for the azomethine proton, which was undetectable with nifurtimox and nitrofurazone.
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Affiliation(s)
- S H Fernandez Villamil
- Bioenergetics Research Centre, School of Medicine, University of Buenos Aires, Argentina
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25
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Cohen JR, Dubin M. Deep venous thrombosis of the upper extremity. N Y State J Med 1988; 88:177-9. [PMID: 3386930] [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: 01/05/2023]
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Abstract
Two nitrofuran compounds, nifurtimox and nitrofurantoin, inhibited in a concentration-dependent manner the NADPH-, iron-induced lipid peroxidation in rat liver microsomes, as shown by the decreased rate of MDA accumulation. Other nitro compounds (benznidazole and chloramphenicol) were relatively inactive. Nifurtimox inhibition affected polyenoic fatty acids and cytochrome P-450 degradation that follows lipid peroxidation. The ascorbate- or tert-butyl hydroperoxide-dependent lipid peroxidations were much less inhibited than the NADPH-dependent one. Nifurtimox and nitrofurantoin, but not benznidazole and chloramphenicol, strongly stimulated the microsomal NADPH-oxidase activity, thus supporting electron diversion, as the main cause of the inhibition of peroxidation initiation.
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27
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Dubin M, Goijman SG, Stoppani AO. Effect of nitroheterocyclic drugs on lipid peroxidation and glutathione content in rat liver extracts. Biochem Pharmacol 1984; 33:3419-23. [PMID: 6497901 DOI: 10.1016/0006-2952(84)90114-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Incubation of rat liver cell-free extracts with an NADPH-generating system and with nifurtimox or benznidazole (two nitroheterocyclic drugs used in the treatment of Chagas' disease) produced oxidation of reduced glutathione (GSH) and increased lipid peroxidation, as shown by the generation of thiobarbituric-acid-reacting intermediates. Nifurtimox and benznidazole inhibited GSSG-reductase, but not GSH-peroxidase, the former inhibition contributing to GSH depletion. In every case, nifurtimox was more effective than benznidazole. Addition of GSH or free-radical scavengers (catalase, superoxide dismutase, mannitol, sodium benzoate or L-histidine) prevented the effect of nifurtimox on lipid peroxidation reactions. These results support the assumption [M. Dubin, S. N. J. Moreno, E. E. Martino, R. Docampo and A. O. M. Dubin, Biochem. Pharmac. 32, 483 (1983)] that, in the rat liver, GSH exerts a protective action against oxygen radicals generated by the nitroheterocyclic drugs.
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28
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Dubin M, Moreno SN, Martino EE, Docampo R, Stoppani AO. Increased biliary secretion and loss of hepatic glutathione in rat liver after nifurtimox treatment. Biochem Pharmacol 1983; 32:483-7. [PMID: 6847698 DOI: 10.1016/0006-2952(83)90527-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Treatment of rats with nifurtimox, a nitrofuran derivative widely used for the treatment of Chagas' disease, induced a time- and dose-dependent depletion of liver glutathione, maximal effects being obtained with 200 mg nifurtimox/kg body weight. Extra release of both oxidized (GSSG) and reduced (GSH) glutathione into bile contributed to this depletion. Glutathione excretion into bile accounted for only part of liver glutathione loss, thus indicating that, in addition to the GSH-peroxidase reaction (resulting in GSSG generation), other glutathione-related processes were involved in nifurtimox detoxification. Bile flow, bile salt excretion, liver lipid conjugated diene content, liver glutathione reductase and glutathione peroxidase activities, and serum alanine aminotransferase (ALAT) activity were not affected by the nifurtimox treatment, thus ruling out widespread damage of the liver cell by nifurtimox. Nevertheless, the extra GSH release in the nifurtimox-treated rats may indicate an alteration of the hepatocyte membrane.
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Dubin M, Maurice M, Feldmann G, Erlinger S. Influence of colchicine and phalloidin on bile secretion and hepatic ultrastructure in the rat. Possible interaction between microtubules and microfilaments. Gastroenterology 1980; 79:646-54. [PMID: 7190948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The studies were carried out to examine the role of microtubules and microfilaments on bile secretion in the rat in vivo. Phalloidin (which causes irreversible polymerization of actin into microfilaments), administered at the dose of 50 microgram/100 g body wt during 3 days, caused an increase in the microfilamentous network around bile canaliculi; it induced a significant decrease both in basal bile flow, and in bile flow stimulated by sodium taurocholate, the major bile acid in the rat. Colchicine (which inhibits the polymerization of tubulin into microtubules), 3 hr after an injection of 0.2 mg/100 g body wt, caused the almost complete disappearance of microtubules in the hepatocytes; it did not modify basal bile secretion, but did induce a significant decrease in taurocholate secretion and taurocholate-stimulated bile flow after a bile-acid load, as well as a delayed plasma disappearance of the bile acid. Lumicolchicine, which is known to have no effect on tubulin, had no effect on bile secretion. The combined administration of phalloidin and colchicine caused both the increase of the pericanalicular microfilamentous network and the disappearance of microtubules; it induced a decrease in basal bile flow that was more marked than that observed with phalloidin alone, suggesting that the effects of the two drugs were not simply additive, but synergic. Although a toxic effect of colchicine could not be totally excluded, the results are compatible with the hypothesis that microtubules as well as microfilaments play a role in the excretion of a bile-acid load.
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Abstract
1. The effect phalloidin on bile acid, phospholipid and cholesterol secretion into bile was studied in rats with bile fistulae. 2. Phalloidin, when given for 7 days, induced a significant decrease in biliary cholesterol concentration and cholesterol saturation index. Bile acid and phospholipid concentration in bile remained unchanged. This effect was less marked in animals receiving the drug for 3 days, and not detectable in animals treated for 1 day. 3. These results provide circumstantial evidence for the hypothesis that microfilament dysfunction may lead to alterations in cholesterol secretion into bile.
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Dubin M, Maurice M, Feldmann G, Erlinger S. Phalloidin-induced cholestasis in the rat: relation to changes in microfilaments. Gastroenterology 1978; 75:450-5. [PMID: 680500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The influence of phalloidin, an agent that causes irreversible polymerisation of actin into microfilaments, on bile secretion and hepatocyte ultrastructure was examined in rats. Phalloidin was given intraperitoneally at the dose of 50 microgram per 100 g of body weight per day for 1, 3, or 7 days. The following was observed. (1) Bile flow decreased, as compared to controls, by 19% after 1 day, 34% after 3 days, and 55% after 7 days. Bile acid secretion was also decreased. (2) Electron microscopic examination of the hepatocyte in treated animals revealed an increased thickness of the pericanalicular microfilamentous network and a dilatation of bile canaliculi. Stereological examination revealed an increase in the relative volume of the microfilamentous network (per unit of hepatocyte cytoplasm) of 2.55% after 1 day, 4.06% ater 3 days, and 6.16% after 7 days. (3) [14C]Erythritol biliary clearance, measured after 7 days, decreased in parallel to bile flow, suggesting that the decrease in bile flow was of canalicular origin. [14C]Sucrose biliary clearance increased in treated animals, suggesting an increased permeability of the biliary system to sucrose. There was a predominant decrease in the bile acid independent bile flow. These data provide circumstantial evidence for the hypothesis that microfilament dysfunction can produce cholestasis.
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Abstract
This study was undertaken to assess the reliability of the constant infusion clearance and extraction technique (CIT) and the single injection clearance method (SIT), to measure hepatic perfusate flow at different levels of liver function. In the 36 isolated perfused dog livers, hepatic perfusate flow(HPF) was monitored by a direct method (DM), and the HPF was simultaneously measured with an indirect method (IM) utilizing bromosulphophthalein BSP) as indicator (20 SIT and 16 SIT). In 16 experiments, absolute ethanol (750 mM) and sodium taurocholate (600 muM) were seperately utilized to impair BSP metabolism. By comparison with DM, in the experiments with an extraction ratio(ER) of BSP lower than 10%, the error of the IM (ml/min) was for the CIT 154.57 +/- 46.55 and for the SIT 107.25 +/- 34.20. This error was significantly greater than in the experiments with an ER greater than 10% (CIT 15.70 +/- 3.88, SIT 8.20 +/- 1.38) p less than 0.01. In the studies with ER less than 10%, no difference was found in the error detected with the SIT (107 +/- 34.20) and CIT measurements (154.37 +/- 46.55); in the experiments with an ER greater than 10%, the error with the CIT (15.70 +/- 3.88) was greater than the one attained with the SIT (8.20 +/- 1.38, p less than 0.10 greater than 0.05). It is concluded that both methods are reliable techniques, for measuring HPF in livers with normal or near normal clearance capacity, but even in these ideal experimental conditions the values for HPF are inacurate when the liver clearance function is moderate or severly impaired.
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Royer M, Dubin M, Kravetz D. Evaluation of the Malloy-Evelyn and Jendrassik-Cleghorn methods for the determination of plasma bilirubin. Acta Gastroenterol Latinoam 1973; 5:167-73. [PMID: 4794935] [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: 01/12/2023]
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34
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Royer M, Dubin M. [Determination of nonconjugated bilirubin in bile]. Rev Soc Argent Biol 1971; 46:36-41. [PMID: 5120500] [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: 01/13/2023]
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35
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Dubin M, Roselle HA, Mezey E. Traumatic diaphragmatic hernia simulating transient pleural effusion. N Y State J Med 1968; 68:1167-71. [PMID: 5239974] [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: 01/14/2023]
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36
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Pierson RN, Grieco M, Swinton N, Dubin M. Circulation time end points. A quantitative comparison of saccharin and radioiodinated albumin as indicators. Circulation 1966; 34:997-1004. [PMID: 5333245 DOI: 10.1161/01.cir.34.6.997] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Ideal measurements are both simple and precise. The subjective circulation time has provided more simplicity than precision to three generations of physicians attempting to analyze cardiac function. Other more complex and less available measurements have displaced the circulation time from its prior vogue, probably because of the wide ranges of normal circulation time values. Yet, no other bedside measurement of cardiac function reflects both cardiac output and central blood volume with a single result.
The peripheral arrival characteristics of radioisotope-labeled albumin are described in 15 normal subjects and in 13 patients with heart failure. These circulation-times are compared with the taste end point of the saccharin indicator simultaneously injected.
Taste threshold, a variable not dependent on cardiac status, determines a significant proportion of the circulation time in both normal and failing circulations.
The wide availability of instruments which measure radioactivity, dye density, or thermal change as a function of time could reinvest the circulation time with a new precision, in return for a modest loss of simplicity. Bypass of the noncardiac variable taste threshold may be added to the other well-described advantages of an objective circulation-time measurement by use of the time of half-peak concentration as the end point in recording the circulation time.
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