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Brañas Casas R, Zuppardo A, Risato G, Dinarello A, Celeghin R, Fontana C, Grelloni E, Gilea AI, Viscomi C, Rasola A, Dalla Valle L, Lodi T, Baruffini E, Facchinello N, Argenton F, Tiso N. Zebrafish polg2 knock-out recapitulates human POLG-disorders; implications for drug treatment. Cell Death Dis 2024; 15:281. [PMID: 38643274 PMCID: PMC11032366 DOI: 10.1038/s41419-024-06622-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 04/22/2024]
Abstract
The human mitochondrial DNA polymerase gamma is a holoenzyme, involved in mitochondrial DNA (mtDNA) replication and maintenance, composed of a catalytic subunit (POLG) and a dimeric accessory subunit (POLG2) conferring processivity. Mutations in POLG or POLG2 cause POLG-related diseases in humans, leading to a subset of Mendelian-inherited mitochondrial disorders characterized by mtDNA depletion (MDD) or accumulation of multiple deletions, presenting multi-organ defects and often leading to premature death at a young age. Considering the paucity of POLG2 models, we have generated a stable zebrafish polg2 mutant line (polg2ia304) by CRISPR/Cas9 technology, carrying a 10-nucleotide deletion with frameshift mutation and premature stop codon. Zebrafish polg2 homozygous mutants present slower development and decreased viability compared to wild type siblings, dying before the juvenile stage. Mutants display a set of POLG-related phenotypes comparable to the symptoms of human patients affected by POLG-related diseases, including remarkable MDD, altered mitochondrial network and dynamics, and reduced mitochondrial respiration. Histological analyses detected morphological alterations in high-energy demanding tissues, along with a significant disorganization of skeletal muscle fibres. Consistent with the last finding, locomotor assays highlighted a decreased larval motility. Of note, treatment with the Clofilium tosylate drug, previously shown to be effective in POLG models, could partially rescue MDD in Polg2 mutant animals. Altogether, our results point at zebrafish as an effective model to study the etiopathology of human POLG-related disorders linked to POLG2, and a suitable platform to screen the efficacy of POLG-directed drugs in POLG2-associated forms.
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Affiliation(s)
| | - Alessandro Zuppardo
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy
| | - Giovanni Risato
- Department of Biology, University of Padova, Padova, 35131, Italy
- Department of Cardio-Thoraco-Vascular Sciences and Public Health, University of Padova, Padova, 35128, Italy
| | - Alberto Dinarello
- Department of Biology, University of Padova, Padova, 35131, Italy
- Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), University of Copenhagen, Copenhagen, 2200, Denmark
| | - Rudy Celeghin
- Department of Cardio-Thoraco-Vascular Sciences and Public Health, University of Padova, Padova, 35128, Italy
| | - Camilla Fontana
- Department of Biology, University of Padova, Padova, 35131, Italy
- Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai, 50200, Thailand
| | | | - Alexandru Ionut Gilea
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Carlo Viscomi
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy
| | - Andrea Rasola
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy
| | | | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Nicola Facchinello
- Neuroscience Institute, Italian Research Council (CNR), 35131, Padova, Italy.
| | | | - Natascia Tiso
- Department of Biology, University of Padova, Padova, 35131, Italy.
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Ceriani V, Pinna F, Lodi T, Tagliabue M, Guarino S, Pontiroli AE. Weight Loss and Nutritional Aspects After Biliopancreatic Diversion and Its Variants. Obes Surg 2022; 32:2094-2095. [PMID: 35414008 DOI: 10.1007/s11695-022-06057-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 10/18/2022]
Affiliation(s)
- Valerio Ceriani
- Dipartimento di Chirurgia Generale, IRCCS Multimedica, Milan, Italy
| | - Ferdinando Pinna
- Dipartimento di Chirurgia Generale, IRCCS Multimedica, Milan, Italy
| | - Tiziana Lodi
- Dipartimento di Chirurgia Generale, IRCCS Multimedica, Milan, Italy
| | - Marta Tagliabue
- Dipartimento di Chirurgia Generale, IRCCS Multimedica, Milan, Italy
| | | | - Antonio E Pontiroli
- Dipartimento di Scienze Della Salute, Università degli Studi di Milano, Ospedale San Paolo, Via Antonio di Rudinì 8, 20142, Milan, Italy.
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di Punzio G, Gilberti M, Baruffini E, Lodi T, Donnini C, Dallabona C. A Yeast-Based Repurposing Approach for the Treatment of Mitochondrial DNA Depletion Syndromes Led to the Identification of Molecules Able to Modulate the dNTP Pool. Int J Mol Sci 2021; 22:ijms222212223. [PMID: 34830106 PMCID: PMC8621932 DOI: 10.3390/ijms222212223] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 12/30/2022] Open
Abstract
Mitochondrial DNA depletion syndromes (MDS) are clinically heterogenous and often severe diseases, characterized by a reduction of the number of copies of mitochondrial DNA (mtDNA) in affected tissues. In the context of MDS, yeast has proved to be both an excellent model for the study of the mechanisms underlying mitochondrial pathologies and for the discovery of new therapies via high-throughput assays. Among the several genes involved in MDS, it has been shown that recessive mutations in MPV17 cause a hepatocerebral form of MDS and Navajo neurohepatopathy. MPV17 encodes a non selective channel in the inner mitochondrial membrane, but its physiological role and the nature of its cargo remains elusive. In this study we identify ten drugs active against MPV17 disorder, modelled in yeast using the homologous gene SYM1. All ten of the identified molecules cause a concomitant increase of both the mitochondrial deoxyribonucleoside triphosphate (mtdNTP) pool and mtDNA stability, which suggests that the reduced availability of DNA synthesis precursors is the cause for the mtDNA deletion and depletion associated with Sym1 deficiency. We finally evaluated the effect of these molecules on mtDNA stability in two other MDS yeast models, extending the potential use of these drugs to a wider range of MDS patients.
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Ceccatelli Berti C, di Punzio G, Dallabona C, Baruffini E, Goffrini P, Lodi T, Donnini C. The Power of Yeast in Modelling Human Nuclear Mutations Associated with Mitochondrial Diseases. Genes (Basel) 2021; 12:300. [PMID: 33672627 PMCID: PMC7924180 DOI: 10.3390/genes12020300] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 12/17/2022] Open
Abstract
The increasing application of next generation sequencing approaches to the analysis of human exome and whole genome data has enabled the identification of novel variants and new genes involved in mitochondrial diseases. The ability of surviving in the absence of oxidative phosphorylation (OXPHOS) and mitochondrial genome makes the yeast Saccharomyces cerevisiae an excellent model system for investigating the role of these new variants in mitochondrial-related conditions and dissecting the molecular mechanisms associated with these diseases. The aim of this review was to highlight the main advantages offered by this model for the study of mitochondrial diseases, from the validation and characterisation of novel mutations to the dissection of the role played by genes in mitochondrial functionality and the discovery of potential therapeutic molecules. The review also provides a summary of the main contributions to the understanding of mitochondrial diseases emerged from the study of this simple eukaryotic organism.
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Affiliation(s)
| | | | | | | | | | | | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy; (C.C.B.); (G.d.P.); (C.D.); (E.B.); (P.G.); (T.L.)
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Aleo SJ, Del Dotto V, Fogazza M, Maresca A, Lodi T, Goffrini P, Ghelli A, Rugolo M, Carelli V, Baruffini E, Zanna C. Drug repositioning as a therapeutic strategy for neurodegenerations associated with OPA1 mutations. Hum Mol Genet 2020; 29:3631-3645. [PMID: 33231680 PMCID: PMC7823107 DOI: 10.1093/hmg/ddaa244] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/19/2020] [Accepted: 10/30/2020] [Indexed: 12/15/2022] Open
Abstract
OPA1 mutations are the major cause of dominant optic atrophy (DOA) and the syndromic form DOA plus, pathologies for which there is no established cure. We used a ‘drug repurposing’ approach to identify FDA-approved molecules able to rescue the mitochondrial dysfunctions induced by OPA1 mutations. We screened two different chemical libraries by using two yeast strains carrying the mgm1I322M and the chim3P646L mutations, identifying 26 drugs able to rescue their oxidative growth phenotype. Six of them, able to reduce the mitochondrial DNA instability in yeast, have been then tested in Opa1 deleted mouse embryonic fibroblasts expressing the human OPA1 isoform 1 bearing the R445H and D603H mutations. Some of these molecules were able to ameliorate the energetic functions and/or the mitochondrial network morphology, depending on the type of OPA1 mutation. The final validation has been performed in patients’ fibroblasts, allowing to select the most effective molecules. Our current results are instrumental to rapidly translating the findings of this drug repurposing approach into clinical trial for DOA and other neurodegenerations caused by OPA1 mutations.
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Affiliation(s)
- Serena J Aleo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Valentina Del Dotto
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna 40139, Italy
| | - Mario Fogazza
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Alessandra Maresca
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna 40139, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma 43124, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma 43124, Italy
| | - Anna Ghelli
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Michela Rugolo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Valerio Carelli
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna 40139, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna 40139, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma 43124, Italy
| | - Claudia Zanna
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
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Hoyos-Gonzalez N, Trasviña-Arenas CH, Degiorgi A, Castro-Lara AY, Peralta-Castro A, Jimenez-Sandoval P, Diaz-Quezada C, Lodi T, Baruffini E, Brieba LG. Modeling of pathogenic variants of mitochondrial DNA polymerase: insight into the replication defects and implication for human disease. Biochim Biophys Acta Gen Subj 2020; 1864:129608. [PMID: 32234506 DOI: 10.1016/j.bbagen.2020.129608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 03/07/2020] [Accepted: 03/25/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Mutations in human gene encoding the mitochondrial DNA polymerase γ (HsPolγ) are associated with a broad range of mitochondrial diseases. Here we studied the impact on DNA replication by disease variants clustered around residue HsPolγ-K1191, a residue that in several family-A DNA polymerases interacts with the 3' end of the primer. METHODS Specifically, we examined the effect of HsPolγ carrying pathogenic variants in residues D1184, I1185, C1188, K1191, D1196, and a stop codon at residue T1199, using as a model the yeast mitochondrial DNA polymerase protein, Mip1p. RESULTS The introduction of pathogenic variants C1188R (yV945R), and of a stop codon at residue T1199 (yT956X) abolished both polymerization and exonucleolysis in vitro. HsPolγ substitutions in residues D1184 (yD941), I1185 (yI942), K1191 (yK948) and D1196 (yD953) shifted the balance between polymerization and exonucleolysis in favor of exonucleolysis. HsPolγ pathogenic variants at residue K1191 (yK948) and D1184 (yD941) were capable of nucleotide incorporation albeit with reduced processivity. Structural analysis of mitochondrial DNAPs showed that residue HsPolγ-N864 is placed in an optimal distance to interact with the 3' end of the primer and the phosphate backbone previous to the 3' end. Amino acid changes in residue HsPolγ-N864 to Ala, Ser or Asp result in enzymes that did not decrease their polymerization activity on short templates but exhibited a substantial decrease for processive DNA synthesis. CONCLUSION Our data suggest that in mitochondrial DNA polymerases multiple amino acids are involved in the primer-stand stabilization.
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Affiliation(s)
- Nallely Hoyos-Gonzalez
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 629, CP 36821 Irapuato, Guanajuato, Mexico
| | - Carlos H Trasviña-Arenas
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 629, CP 36821 Irapuato, Guanajuato, Mexico
| | - Andrea Degiorgi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Atzimaba Y Castro-Lara
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 629, CP 36821 Irapuato, Guanajuato, Mexico
| | - Antolín Peralta-Castro
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 629, CP 36821 Irapuato, Guanajuato, Mexico
| | - Pedro Jimenez-Sandoval
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 629, CP 36821 Irapuato, Guanajuato, Mexico
| | - Corina Diaz-Quezada
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 629, CP 36821 Irapuato, Guanajuato, Mexico
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy.
| | - Luis G Brieba
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 629, CP 36821 Irapuato, Guanajuato, Mexico.
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Dallabona C, Pioli M, Spadola G, Orsoni N, Bisceglie F, Lodi T, Pelosi G, Restivo FM, Degola F. Sabotage at the Powerhouse? Unraveling the Molecular Target of 2-Isopropylbenzaldehyde Thiosemicarbazone, a Specific Inhibitor of Aflatoxin Biosynthesis and Sclerotia Development in Aspergillus flavus, Using Yeast as a Model System. Molecules 2019; 24:molecules24162971. [PMID: 31426298 PMCID: PMC6719062 DOI: 10.3390/molecules24162971] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/11/2019] [Accepted: 08/14/2019] [Indexed: 11/16/2022] Open
Abstract
Amongst the various approaches to contain aflatoxin contamination of feed and food commodities, the use of inhibitors of fungal growth and/or toxin biosynthesis is showing great promise for the implementation or the replacement of conventional pesticide-based strategies. Several inhibition mechanisms were found taking place at different levels in the biology of the aflatoxin-producing fungal species such as Aspergillus flavus: compounds that influence aflatoxin production may block the biosynthetic pathway through the direct control of genes belonging to the aflatoxin gene cluster, or interfere with one or more of the several steps involved in the aflatoxin metabolism upstream. Recent findings pointed to mitochondrial functionality as one of the potential targets of some aflatoxin inhibitors. Additionally, we have recently reported that the effect of a compound belonging to the class of thiosemicarbazones might be related to the energy generation/carbon flow and redox homeostasis control by the fungal cell. Here, we report our investigation about a putative molecular target of the 3-isopropylbenzaldehyde thiosemicarbazone (mHtcum), using the yeast Saccharomyces cerevisiae as model system, to demonstrate how the compound can actually interfere with the mitochondrial respiratory chain.
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Affiliation(s)
- Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Marianna Pioli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Giorgio Spadola
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Nicolò Orsoni
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Franco Bisceglie
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Giorgio Pelosi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Francesco Maria Restivo
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Francesca Degola
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy.
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Daghino S, Di Vietro L, Petiti L, Martino E, Dallabona C, Lodi T, Perotto S. Yeast expression of mammalian Onzin and fungal FCR1 suggests ancestral functions of PLAC8 proteins in mitochondrial metabolism and DNA repair. Sci Rep 2019; 9:6629. [PMID: 31036870 PMCID: PMC6488628 DOI: 10.1038/s41598-019-43136-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [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] [Received: 10/02/2018] [Accepted: 04/11/2019] [Indexed: 01/07/2023] Open
Abstract
The cysteine-rich PLAC8 domain of unknown function occurs in proteins found in most Eukaryotes. PLAC8-proteins play important yet diverse roles in different organisms, such as control of cell proliferation in animals and plants or heavy metal resistance in plants and fungi. Mammalian Onzin can be either pro-proliferative or pro-apoptotic, depending on the cell type, whereas fungal FCR1 confers cadmium tolerance. Despite their different role in different organisms, we hypothesized common ancestral functions linked to the PLAC8 domain. To address this hypothesis, and to investigate the molecular function of the PLAC8 domain, murine Onzin and fungal FCR1 were expressed in the PLAC8-free yeast Saccharomyces cerevisiae. The two PLAC8-proteins localized in the nucleus and induced almost identical phenotypes and transcriptional changes when exposed to cadmium stress. Like FCR1, Onzin also reduced DNA damage and increased cadmium tolerance by a DUN1-dependent pathway. Both proteins activated transcription of ancient mitochondrial pathways such as leucine and Fe-S cluster biosynthesis, known to regulate cell proliferation and DNA repair in yeast. These results strongly suggest a common ancestral function of PLAC8 proteins and open new perspectives to understand the role of the PLAC8 domain in the cellular biology of Eukaryotes.
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Affiliation(s)
- Stefania Daghino
- Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125, Torino, Italy
| | - Luigi Di Vietro
- Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125, Torino, Italy.,Department of Biochemistry and Biotechnology, Bayer SAS, centre de recherche "la Dargoire" 14, impasse Pierre Baizet CS 99163, 69263, Lyon, CEDEX 09, France
| | - Luca Petiti
- Italian Institute for Genomic Medicine, via Nizza 52, 10126, Torino, Italy
| | - Elena Martino
- Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125, Torino, Italy
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Viale delle Scienze 11/A, 43124, Parma, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Viale delle Scienze 11/A, 43124, Parma, Italy
| | - Silvia Perotto
- Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125, Torino, Italy.
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Del Dotto V, Fogazza M, Musiani F, Maresca A, Aleo SJ, Caporali L, La Morgia C, Nolli C, Lodi T, Goffrini P, Chan D, Carelli V, Rugolo M, Baruffini E, Zanna C. Deciphering OPA1 mutations pathogenicity by combined analysis of human, mouse and yeast cell models. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3496-3514. [PMID: 30293569 DOI: 10.1016/j.bbadis.2018.08.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 07/24/2018] [Accepted: 08/01/2018] [Indexed: 11/19/2022]
Abstract
OPA1 is the major gene responsible for Dominant Optic Atrophy (DOA) and the syndromic form DOA "plus". Over 370 OPA1 mutations have been identified so far, although their pathogenicity is not always clear. We have analyzed one novel and a set of known OPA1 mutations to investigate their impact on protein functions in primary skin fibroblasts and in two "ad hoc" generated cell systems: the MGM1/OPA1 chimera yeast model and the Opa1-/- MEFs model expressing the mutated human OPA1 isoform 1. The yeast model allowed us to confirm the deleterious effects of these mutations and to gain information on their dominance/recessivity. The MEFs model enhanced the phenotypic alteration caused by mutations, nicely correlating with the clinical severity observed in patients, and suggested that the DOA "plus" phenotype could be induced by the combinatorial effect of mitochondrial network fragmentation with variable degrees of mtDNA depletion. Overall, the two models proved to be valuable tools to functionally assess and define the deleterious mechanism and the pathogenicity of novel OPA1 mutations, and useful to testing new therapeutic interventions.
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Affiliation(s)
- Valentina Del Dotto
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, 40139 Bologna, Italy
| | - Mario Fogazza
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Francesco Musiani
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Alessandra Maresca
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Serena J Aleo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Leonardo Caporali
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Chiara La Morgia
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, 40139 Bologna, Italy; IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Cecilia Nolli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - David Chan
- Division of Biology and Biological Engineering, California Institute of Technology (CALTECH), Pasadena, CA 91125, USA
| | - Valerio Carelli
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, 40139 Bologna, Italy; IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Michela Rugolo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Claudia Zanna
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy.
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10
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Garone C, D’Souza AR, Dallabona C, Lodi T, Rebelo-Guiomar P, Rorbach J, Donati MA, Procopio E, Montomoli M, Guerrini R, Zeviani M, Calvo SE, Mootha VK, DiMauro S, Ferrero I, Minczuk M. Defective mitochondrial rRNA methyltransferase MRM2 causes MELAS-like clinical syndrome. Hum Mol Genet 2017; 26:4257-4266. [PMID: 28973171 PMCID: PMC5886288 DOI: 10.1093/hmg/ddx314] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [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: 07/13/2017] [Revised: 08/01/2017] [Accepted: 08/03/2017] [Indexed: 02/02/2023] Open
Abstract
Defects in nuclear-encoded proteins of the mitochondrial translation machinery cause early-onset and tissue-specific deficiency of one or more OXPHOS complexes. Here, we report a 7-year-old Italian boy with childhood-onset rapidly progressive encephalomyopathy and stroke-like episodes. Multiple OXPHOS defects and decreased mtDNA copy number (40%) were detected in muscle homogenate. Clinical features combined with low level of plasma citrulline were highly suggestive of mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome, however, the common m.3243 A > G mutation was excluded. Targeted exome sequencing of genes encoding the mitochondrial proteome identified a damaging mutation, c.567 G > A, affecting a highly conserved amino acid residue (p.Gly189Arg) of the MRM2 protein. MRM2 has never before been linked to a human disease and encodes an enzyme responsible for 2'-O-methyl modification at position U1369 in the human mitochondrial 16S rRNA. We generated a knockout yeast model for the orthologous gene that showed a defect in respiration and the reduction of the 2'-O-methyl modification at the equivalent position (U2791) in the yeast mitochondrial 21S rRNA. Complementation with the mrm2 allele carrying the equivalent yeast mutation failed to rescue the respiratory phenotype, which was instead completely rescued by expressing the wild-type allele. Our findings establish that defective MRM2 causes a MELAS-like phenotype, and suggests the genetic screening of the MRM2 gene in patients with a m.3243 A > G negative MELAS-like presentation.
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Affiliation(s)
- Caterina Garone
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - Aaron R D’Souza
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability - University of Parma, Parma 43121, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability - University of Parma, Parma 43121, Italy
| | - Pedro Rebelo-Guiomar
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
- Graduate Program in Areas of Basic and Applied Biology (GABBA), University of Porto, 4099-002, Portugal
| | - Joanna Rorbach
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | | | - Elena Procopio
- Metabolic Unit, A. Meyer Children's Hospital, Florence 50139, Italy
| | - Martino Montomoli
- Pediatric Neurology Unit and Laboratories, “A. Meyer” Children's Hospital, University of Florence, 50139, Italy
| | - Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, “A. Meyer” Children's Hospital, University of Florence, 50139, Italy
| | - Massimo Zeviani
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Sarah E Calvo
- Broad Institute of MIT & Harvard, Cambridge, MA 02142, USA
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, and Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Vamsi K Mootha
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, and Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Salvatore DiMauro
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - Ileana Ferrero
- Department of Chemistry, Life Sciences and Environmental Sustainability - University of Parma, Parma 43121, Italy
| | - Michal Minczuk
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
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11
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Dallabona C, Baruffini E, Goffrini P, Lodi T. Dominance of yeast aac2 R96H and aac2 R252G mutations, equivalent to pathological mutations in ant1, is due to gain of function. Biochem Biophys Res Commun 2017; 493:909-913. [PMID: 28947214 DOI: 10.1016/j.bbrc.2017.09.122] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 09/21/2017] [Indexed: 01/20/2023]
Abstract
The mitochondrial ADP/ATP carrier is a nuclear encoded protein, which catalyzes the exchange of ATP generated in mitochondria with ADP produced in the cytosol. In humans, mutations in the major ADP/ATP carrier gene, ANT1, are involved in several degenerative mitochondrial pathologies, leading to instability of mitochondrial DNA. Recessive mutations have been associated with mitochondrial myopathy and cardiomyopathy whereas dominant mutations have been associated with autosomal dominant Progressive External Ophtalmoplegia (adPEO). Recently, two de novo dominant mutations, R80H and R235G, leading to extremely severe symptoms, have been identified. In order to evaluate if the dominance is due to haploinsufficiency or to a gain of function, the two mutations have been introduced in the equivalent positions of the AAC2 gene, the yeast orthologue of human ANT1, and their dominant effect has been studied in heteroallelic strains, containing both one copy of wild type AAC2 and one copy of mutant aac2 allele. Through phenotypic characterization of these yeast models we showed that the OXPHOS phenotypes in the heteroallelic strains were more affected than in the hemiallelic strain indicating that the dominant trait of the two mutations is due to gain of function.
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Affiliation(s)
- Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
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12
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Ceriani V, Pinna F, Lodi T, Pontiroli AE. Revision of Biliopancreatic Diversion for Side Effects or Insufficient Weight Loss: Codification of a New Procedure. Obes Surg 2017; 27:1091-1097. [PMID: 28197865 DOI: 10.1007/s11695-017-2575-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE Addressing the problem of proctologic sequelae after Scopinaro's classical BPD, we elongated the common limb from 50 to 200 cm at the expense of the alimentary limb and simultaneously, with the aim of avoiding weight regain, reduced the gastric pouch from 500 to 40 ml. After increased experience with the new procedure, we observed a favourable tendency towards further weight loss. Thus, we subsequently extended the indication to the procedure to patients with unsatisfactory weight loss after Scopinaro's classical BPD (SBPD). METHODS We retrospectively reviewed our clinical experience with the new procedure. RESULTS From March 2008 to December 2014, 38 patients were submitted to the revisional procedure. The indication to surgical revision was proctologic in 26 patients and unsatisfactory weight loss in 12. After the revisional procedure, a significant reduction in bowel movements per day was observed, together with a significant reduction in body weight (from preoperative 87.1 ± 21 to 69.2 ± 13.5 kg at post-operative year 1 and 68.1 ± 11.9 kg at year 5; p < 0.001) and a parallel reduction in BMI (from preoperative 33.03 ± 7.6 to 26.8 ± 4.1 at post-operative year 1 and 26.9 ± 2.8 at year 5; p < 0.001). Mean excess BMI percent loss was 49.5 ± 94.6% at post-operative month 3, 76.51 ± 74.9% at year 1 and 76.2 ± 31.3% at year 5. Nutritional and metabolic parameters remained stable. Similar results were observed, analysing separately both groups of patients. CONCLUSIONS Our preliminary data suggest that the proposed procedure could represent a safe and effective revisional tool to treat invalidating proctologic sequelae after SBPD, or when weight loss may be deemed unsatisfactory.
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Affiliation(s)
- Valerio Ceriani
- General Surgery, IRCCS Multimedica, Via Milanese 300, Sesto San Giovanni, 20099, Milan, Italy
| | - Ferdinando Pinna
- General Surgery, IRCCS Multimedica, Via Milanese 300, Sesto San Giovanni, 20099, Milan, Italy.
| | - Tiziana Lodi
- General Surgery, IRCCS Multimedica, Via Milanese 300, Sesto San Giovanni, 20099, Milan, Italy
| | - Antonio E Pontiroli
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milan, Italy
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13
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Thompson K, Majd H, Dallabona C, Reinson K, King M, Alston C, He L, Lodi T, Jones S, Fattal-Valevski A, Fraenkel N, Saada A, Haham A, Isohanni P, Vara R, Barbosa I, Simpson M, Deshpande C, Puusepp S, Bonnen P, Rodenburg R, Suomalainen A, Õunap K, Elpeleg O, Ferrero I, McFarland R, Kunji E, Taylor R. Recurrent De Novo Dominant Mutations in SLC25A4 Cause Severe Early-Onset Mitochondrial Disease and Loss of Mitochondrial DNA Copy Number. Am J Hum Genet 2016; 99:1405. [PMID: 27912046 PMCID: PMC5142113 DOI: 10.1016/j.ajhg.2016.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
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14
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Thompson K, Majd H, Dallabona C, Reinson K, King MS, Alston CL, He L, Lodi T, Jones SA, Fattal-Valevski A, Fraenkel ND, Saada A, Haham A, Isohanni P, Vara R, Barbosa IA, Simpson MA, Deshpande C, Puusepp S, Bonnen PE, Rodenburg RJ, Suomalainen A, Õunap K, Elpeleg O, Ferrero I, McFarland R, Kunji ERS, Taylor RW. Recurrent De Novo Dominant Mutations in SLC25A4 Cause Severe Early-Onset Mitochondrial Disease and Loss of Mitochondrial DNA Copy Number. Am J Hum Genet 2016; 99:860-876. [PMID: 27693233 PMCID: PMC5065686 DOI: 10.1016/j.ajhg.2016.08.014] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [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: 06/24/2016] [Accepted: 08/18/2016] [Indexed: 11/26/2022] Open
Abstract
Mutations in SLC25A4 encoding the mitochondrial ADP/ATP carrier AAC1 are well-recognized causes of mitochondrial disease. Several heterozygous SLC25A4 mutations cause adult-onset autosomal-dominant progressive external ophthalmoplegia associated with multiple mitochondrial DNA deletions, whereas recessive SLC25A4 mutations cause childhood-onset mitochondrial myopathy and cardiomyopathy. Here, we describe the identification by whole-exome sequencing of seven probands harboring dominant, de novo SLC25A4 mutations. All affected individuals presented at birth, were ventilator dependent and, where tested, revealed severe combined mitochondrial respiratory chain deficiencies associated with a marked loss of mitochondrial DNA copy number in skeletal muscle. Strikingly, an identical c.239G>A (p.Arg80His) mutation was present in four of the seven subjects, and the other three case subjects harbored the same c.703C>G (p.Arg235Gly) mutation. Analysis of skeletal muscle revealed a marked decrease of AAC1 protein levels and loss of respiratory chain complexes containing mitochondrial DNA-encoded subunits. We show that both recombinant AAC1 mutant proteins are severely impaired in ADP/ATP transport, affecting most likely the substrate binding and mechanics of the carrier, respectively. This highly reduced capacity for transport probably affects mitochondrial DNA maintenance and in turn respiration, causing a severe energy crisis. The confirmation of the pathogenicity of these de novo SLC25A4 mutations highlights a third distinct clinical phenotype associated with mutation of this gene and demonstrates that early-onset mitochondrial disease can be caused by recurrent de novo mutations, which has significant implications for the application and analysis of whole-exome sequencing data in mitochondrial disease.
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Affiliation(s)
- Kyle Thompson
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Homa Majd
- The Medical Research Council, Mitochondrial Biology Unit, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Cristina Dallabona
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11A, Parma 43124, Italy
| | - Karit Reinson
- Department of Pediatrics, Institute of Clinical Medicine, University of Tartu, 51014 Tartu, Estonia; Department of Genetics, United Laboratories, Tartu University Hospital, 51014 Tartu, Estonia
| | - Martin S King
- The Medical Research Council, Mitochondrial Biology Unit, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Charlotte L Alston
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Langping He
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Tiziana Lodi
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11A, Parma 43124, Italy
| | - Simon A Jones
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, St Marys Hospital, Oxford Road, Manchester M13 9WL, UK
| | - Aviva Fattal-Valevski
- Paediatric Neurology Unit, "Dana" Children Hospital, Tel Aviv Sourasky Medical Centre, Sackler Faculty of Medicine, Tel Aviv University, 64239 Tel Aviv, Israel
| | - Nitay D Fraenkel
- Department of Respiratory Rehabilitation, Alyn Hospital, Jerusalem 91090, Israel
| | - Ann Saada
- Metabolic Laboratory Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Alon Haham
- Neonatal Intensive Care Unit, "Lis" Maternity Hospital, Tel Aviv Sourasky Medical Centre, 64239 Tel Aviv, Israel
| | - Pirjo Isohanni
- Research Programs Unit, Molecular Neurology, Biomedicum-Helsinki, University of Helsinki, 00290 Helsinki, Finland; Department of Pediatric Neurology, Children's Hospital, Helsinki University Hospital and University of Helsinki, 00290 Helsinki, Finland
| | - Roshni Vara
- Department of Paediatric Inherited Metabolic Diseases, Evelina Children's Hospital, London SE1 7EH, UK
| | - Inês A Barbosa
- Division of Genetics and Molecular Medicine, King's College London School of Medicine, London SE1 9RY, UK
| | - Michael A Simpson
- Division of Genetics and Molecular Medicine, King's College London School of Medicine, London SE1 9RY, UK
| | - Charu Deshpande
- Clinical Genetics Unit, Guys and St Thomas' NHS Foundation Trust, London SE1 9RT, UK
| | - Sanna Puusepp
- Department of Pediatrics, Institute of Clinical Medicine, University of Tartu, 51014 Tartu, Estonia; Department of Genetics, United Laboratories, Tartu University Hospital, 51014 Tartu, Estonia
| | - Penelope E Bonnen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Richard J Rodenburg
- Radboud Center for Mitochondrial Medicine, Department of Paediatrics, Translational Metabolic Laboratory, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Anu Suomalainen
- Research Programs Unit, Molecular Neurology, Biomedicum-Helsinki, University of Helsinki, 00290 Helsinki, Finland; Department of Neurosciences, Helsinki University Hospital and University of Helsinki, 00290 Helsinki, Finland
| | - Katrin Õunap
- Department of Pediatrics, Institute of Clinical Medicine, University of Tartu, 51014 Tartu, Estonia; Department of Genetics, United Laboratories, Tartu University Hospital, 51014 Tartu, Estonia
| | - Orly Elpeleg
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Ileana Ferrero
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11A, Parma 43124, Italy
| | - Robert McFarland
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Edmund R S Kunji
- The Medical Research Council, Mitochondrial Biology Unit, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Robert W Taylor
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
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Pitayu L, Baruffini E, Rodier C, Rötig A, Lodi T, Delahodde A. Combined use of Saccharomyces cerevisiae, Caenorhabditis elegans and patient fibroblasts leads to the identification of clofilium tosylate as a potential therapeutic chemical against POLG-related diseases. Hum Mol Genet 2015; 25:715-27. [PMID: 26692522 DOI: 10.1093/hmg/ddv509] [Citation(s) in RCA: 13] [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: 10/23/2015] [Accepted: 12/08/2015] [Indexed: 11/13/2022] Open
Abstract
Mitochondria are organelles that have their own DNA (mitochondrial DNA, mtDNA) whose maintenance is necessary for the majority of ATP production in eukaryotic cells. Defects in mtDNA maintenance or integrity are responsible for numerous diseases. The DNA polymerase γ (POLG) ensures proper mtDNA replication and repair. Mutations in POLG are a major cause of mitochondrial disorders including hepatic insufficiency, Alpers syndrome, progressive external ophthalmoplegia, sensory neuropathy and ataxia. Mutations in POLG are also associated with parkinsonism. To date, no effective therapy is available. Based on the conservation of mitochondrial function from yeast to human, we used Saccharomyces cerevisiae and Caenorhabditis elegans as first pass filters to identify a chemical that suppresses mtDNA instability in cultured fibroblasts of a POLG-deficient patient. We showed that this unsuspected compound, clofilium tosylate (CLO), belonging to a class of anti-arrhythmic agents, prevents mtDNA loss of all yeast mitochondrial polymerase mutants tested, improves behavior and mtDNA content of polg-1-deficient worms and increases mtDNA content of quiescent POLG-deficient fibroblasts. Furthermore, the mode of action of the drug seems conserved as CLO increases POLG steady-state level in yeast and human cells. Two other anti-arrhythmic agents (FDA-approved) sharing common pharmacological properties and chemical structure also show potential benefit for POLG deficiency in C. elegans. Our findings provide evidence of the first mtDNA-stabilizing compound that may be an effective pharmacological alternative for the treatment of POLG-related diseases.
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Affiliation(s)
- Laras Pitayu
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Enrico Baruffini
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11/a, I-43124 Parma, Italy and
| | - Celine Rodier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Agnès Rötig
- INSERM UMR 1163, Laboratory of Genetics of Mitochondrial Disorders, Paris Descartes - Sorbonne Paris Cité University, Imagine Institute, 24 Boulevard du Montparnasse, Paris 75015, France
| | - Tiziana Lodi
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11/a, I-43124 Parma, Italy and
| | - Agnès Delahodde
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France,
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16
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Nolli C, Goffrini P, Lazzaretti M, Zanna C, Vitale R, Lodi T, Baruffini E. Validation of a MGM1/OPA1 chimeric gene for functional analysis in yeast of mutations associated with dominant optic atrophy. Mitochondrion 2015; 25:38-48. [PMID: 26455272 DOI: 10.1016/j.mito.2015.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/24/2015] [Accepted: 10/01/2015] [Indexed: 01/08/2023]
Abstract
Mutations in OPA1 are associated with DOA or DOA plus. Novel mutations in OPA1 are periodically identified, but often the causative effect of the mutation is not demonstrated. A chimeric protein containing the N-terminal region of Mgm1, the yeast orthologue of OPA1, and the C-terminal region of OPA1 was constructed. This chimeric construct can be exploited to evaluate the pathogenicity of most of the missense mutations in OPA1 as well as to determine whether the dominance of the mutation is due to haploinsufficiency or to gain of function.
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Affiliation(s)
- Cecilia Nolli
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Paola Goffrini
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Mirca Lazzaretti
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Claudia Zanna
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Via Altura 3, 40139 Bologna, Italy
| | - Rita Vitale
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Tiziana Lodi
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Enrico Baruffini
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy.
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17
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Lodi T, Dallabona C, Nolli C, Goffrini P, Donnini C, Baruffini E. DNA polymerase γ and disease: what we have learned from yeast. Front Genet 2015; 6:106. [PMID: 25852747 PMCID: PMC4362329 DOI: 10.3389/fgene.2015.00106] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 03/02/2015] [Indexed: 11/16/2022] Open
Abstract
Mip1 is the Saccharomyces cerevisiae DNA polymerase γ (Pol γ), which is responsible for the replication of mitochondrial DNA (mtDNA). It belongs to the family A of the DNA polymerases and it is orthologs to human POLGA. In humans, mutations in POLG(1) cause many mitochondrial pathologies, such as progressive external ophthalmoplegia (PEO), Alpers' syndrome, and ataxia-neuropathy syndrome, all of which present instability of mtDNA, which results in impaired mitochondrial function in several tissues with variable degrees of severity. In this review, we summarize the genetic and biochemical knowledge published on yeast mitochondrial DNA polymerase from 1989, when the MIP1 gene was first cloned, up until now. The role of yeast is particularly emphasized in (i) validating the pathological mutations found in human POLG and modeled in MIP1, (ii) determining the molecular defects caused by these mutations and (iii) finding the correlation between mutations/polymorphisms in POLGA and mtDNA toxicity induced by specific drugs. We also describe recent findings regarding the discovery of molecules able to rescue the phenotypic defects caused by pathological mutations in Mip1, and the construction of a model system in which the human Pol γ holoenzyme is expressed in yeast and complements the loss of Mip1.
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Affiliation(s)
- Tiziana Lodi
- Department of Life Sciences, University of Parma Parma, Italy
| | | | - Cecilia Nolli
- Department of Life Sciences, University of Parma Parma, Italy
| | - Paola Goffrini
- Department of Life Sciences, University of Parma Parma, Italy
| | - Claudia Donnini
- Department of Life Sciences, University of Parma Parma, Italy
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18
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Degola F, Morcia C, Bisceglie F, Mussi F, Tumino G, Ghizzoni R, Pelosi G, Terzi V, Buschini A, Restivo FM, Lodi T. In vitro evaluation of the activity of thiosemicarbazone derivatives against mycotoxigenic fungi affecting cereals. Int J Food Microbiol 2015; 200:104-11. [PMID: 25702884 DOI: 10.1016/j.ijfoodmicro.2015.02.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 01/26/2015] [Accepted: 02/05/2015] [Indexed: 12/20/2022]
Abstract
With a steadily increasing world population, a more efficient system of food production is of paramount importance. One of the major causes of food spoilage is the presence of fungal pathogens and the production and accumulation of mycotoxins. In the present work we report a study on the activity of a series of functionalized thiosemicarbazones (namely cuminaldehyde, trans-cinnamaldehyde, quinoline-2-carboxyaldehyde, 5-fluoroisatin thiosemicarbazone and 5-fluoroisatin N(4)-methylthiosemicarbazone), as antifungal and anti-mycotoxin agents, against the two major genera of cereal mycotoxigenic fungi, i.e. Fusarium and Aspergillus. These thiosemicarbazones display different patterns of efficacy on fungal growth and on mycotoxin accumulation depending on the fungal species. Some of the molecules display a greater effect on mycotoxin synthesis than on fungal growth.
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Affiliation(s)
| | - Caterina Morcia
- Consiglio per la Ricerca e la sperimentazione in Agricoltura, CRA-GPG, Genomics Research Centre, Fiorenzuola d'Arda, Italy
| | | | - Francesca Mussi
- Dipartimento di Bioscienze, Università di Parma, Parma, Italy
| | - Giorgio Tumino
- Consiglio per la Ricerca e la sperimentazione in Agricoltura, CRA-GPG, Genomics Research Centre, Fiorenzuola d'Arda, Italy
| | - Roberta Ghizzoni
- Consiglio per la Ricerca e la sperimentazione in Agricoltura, CRA-GPG, Genomics Research Centre, Fiorenzuola d'Arda, Italy
| | - Giorgio Pelosi
- Dipartimento di Chimica, Università di Parma, Parma, Italy
| | - Valeria Terzi
- Consiglio per la Ricerca e la sperimentazione in Agricoltura, CRA-GPG, Genomics Research Centre, Fiorenzuola d'Arda, Italy
| | | | | | - Tiziana Lodi
- Dipartimento di Bioscienze, Università di Parma, Parma, Italy
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Zara G, Goffrini P, Lodi T, Zara S, Mannazzu I, Budroni M. FLO11expression and lipid biosynthesis are required for air-liquid biofilm formation in aSaccharomyces cerevisiaeflor strain. FEMS Yeast Res 2012; 12:864-6. [DOI: 10.1111/j.1567-1364.2012.00831.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 07/09/2012] [Accepted: 07/09/2012] [Indexed: 11/30/2022] Open
Affiliation(s)
- Giacomo Zara
- Dipartimento di Agraria; Università di Sassari; Sassari; Italy
| | - Paola Goffrini
- Dipartimento di Genetica; Biologia dei Microrganismi; Antropologia Evoluzione; Università di Parma; Parma; Italy
| | - Tiziana Lodi
- Dipartimento di Genetica; Biologia dei Microrganismi; Antropologia Evoluzione; Università di Parma; Parma; Italy
| | - Severino Zara
- Dipartimento di Agraria; Università di Sassari; Sassari; Italy
| | - Ilaria Mannazzu
- Dipartimento di Agraria; Università di Sassari; Sassari; Italy
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20
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Stricker S, Prüss H, Horvath R, Baruffini E, Lodi T, Siebert E, Endres M, Zschenderlein R, Meisel A. A variable neurodegenerative phenotype with polymerase gamma mutation. J Neurol Neurosurg Psychiatry 2009; 80:1181-2. [PMID: 19762913 DOI: 10.1136/jnnp.2008.166066] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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21
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Di Fonzo A, Ronchi D, Lodi T, Fassone E, Tigano M, Lamperti C, Corti S, Bordoni A, Fortunato F, Nizzardo M, Napoli L, Donadoni C, Salani S, Saladino F, Moggio M, Bresolin N, Ferrero I, Comi GP. The mitochondrial disulfide relay system protein GFER is mutated in autosomal-recessive myopathy with cataract and combined respiratory-chain deficiency. Am J Hum Genet 2009; 84:594-604. [PMID: 19409522 DOI: 10.1016/j.ajhg.2009.04.004] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [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] [Received: 02/02/2009] [Revised: 03/13/2009] [Accepted: 04/08/2009] [Indexed: 11/28/2022] Open
Abstract
A disulfide relay system (DRS) was recently identified in the yeast mitochondrial intermembrane space (IMS) that consists of two essential components: the sulfhydryl oxidase Erv1 and the redox-regulated import receptor Mia40. The DRS drives the import of cysteine-rich proteins into the IMS via an oxidative folding mechanism. Erv1p is reoxidized within this system, transferring its electrons to molecular oxygen through interactions with cytochrome c and cytochrome c oxidase (COX), thereby linking the DRS to the respiratory chain. The role of the human Erv1 ortholog, GFER, in the DRS has been poorly explored. Using homozygosity mapping, we discovered that a mutation in the GFER gene causes an infantile mitochondrial disorder. Three children born to healthy consanguineous parents presented with progressive myopathy and partial combined respiratory-chain deficiency, congenital cataract, sensorineural hearing loss, and developmental delay. The consequences of the mutation at the level of the patient's muscle tissue and fibroblasts were 1) a reduction in complex I, II, and IV activity; 2) a lower cysteine-rich protein content; 3) abnormal ultrastructural morphology of the mitochondria, with enlargement of the IMS space; and 4) accelerated time-dependent accumulation of multiple mtDNA deletions. Moreover, the Saccharomyces cerevisiae erv1(R182H) mutant strain reproduced the complex IV activity defect and exhibited genetic instability of the mtDNA and mitochondrial morphological defects. These findings shed light on the mechanisms of mitochondrial biogenesis, establish the role of GFER in the human DRS, and promote an understanding of the pathogenesis of a new mitochondrial disease.
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Affiliation(s)
- Alessio Di Fonzo
- Dino Ferrari Centre, Department of Neurological Sciences, University of Milan, 20122 Milan, Italy
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22
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Zara G, Angelozzi D, Belviso S, Bardi L, Goffrini P, Lodi T, Budroni M, Mannazzu I. Oxygen is required to restore flor strain viability and lipid biosynthesis under fermentative conditions. FEMS Yeast Res 2009; 9:217-25. [DOI: 10.1111/j.1567-1364.2008.00472.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [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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23
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Saliola M, Sponziello M, D'Amici S, Lodi T, Falcone C. Characterization of KlGUT2, a gene of the glycerol-3-phosphate shuttle, in Kluyveromyces lactis. FEMS Yeast Res 2008; 8:697-705. [PMID: 18503541 DOI: 10.1111/j.1567-1364.2008.00386.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
KlGUT2 encodes the mitochondrial component of the glycerol-3-phosphate shuttle in Kluyveromyces lactis, a dehydrogenase involved in the maintenance of the NADH redox balance and in glycerol utilization. Deletion of KlGUT2 led to glycerol accumulation during growth in glucose and growth retardation in ethanol. In addition, KlGUT2 deletion altered the expression of other mitochondrial dehydrogenases that contribute to the maintenance of the intracellular redox balance, suggesting a rerouting of ethanol oxidation from the cytoplasm to the mitochondria. Finally, Northern analysis showed that KlGUT2 has two transcripts: one constitutively expressed and dependent on HGT1, the high-affinity hexose transporter gene, and the other induced under respiratory conditions.
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Affiliation(s)
- Michele Saliola
- Department of Cell and Developmental Biology, University of Rome La Sapienza, Piazzale Aldo Moro, Rome, Italy.
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24
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Mannazzu I, Angelozzi D, Belviso S, Budroni M, Farris GA, Goffrini P, Lodi T, Marzona M, Bardi L. Behaviour of Saccharomyces cerevisiae wine strains during adaptation to unfavourable conditions of fermentation on synthetic medium: Cell lipid composition, membrane integrity, viability and fermentative activity. Int J Food Microbiol 2008; 121:84-91. [DOI: 10.1016/j.ijfoodmicro.2007.11.003] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Revised: 05/03/2007] [Accepted: 11/02/2007] [Indexed: 11/29/2022]
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25
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Baruffini E, Lodi T, Dallabona C, Foury F. A single nucleotide polymorphism in the DNA polymerase gamma gene of Saccharomyces cerevisiae laboratory strains is responsible for increased mitochondrial DNA mutability. Genetics 2007; 177:1227-31. [PMID: 17720904 PMCID: PMC2034627 DOI: 10.1534/genetics.107.079293] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [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: 11/18/2022] Open
Abstract
In the Saccharomyces cerevisiae strains used for genome sequencing and functional analysis, the mitochondrial DNA replicase Mip1p contains a single nucleotide polymorphism changing the strictly conserved threonine 661 to alanine. This substitution is responsible for the increased rate of mitochondrial DNA point mutations and deletions in these strains.
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Affiliation(s)
- Enrico Baruffini
- Unité de Biochimie Physiologique, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
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26
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Abstract
Synteny analysis is combined with sequence similarity and motif identification to trace the evolution of the putative monocarboxylate (lactate/pyruvate) transporters Jen1p and the dicarboxylate (succinate/fumarate/malate) transporters Jen2p in Hemiascomycetes yeasts and Euascomycetes fungi. It is concluded that a precursor form of Jen1p, named here preJen1p, arose by the duplication of an ancestral Jen2p, during the speciation of Yarrowia lipolytica, which was transferred into a new syntenic context. The Jen1p transporters differentiated from preJen1p in Kluyveromyces lactis, before the Whole Genome Duplication (WGD), and are conserved as a single copy in the Saccharomyces species. In contrast, the ancestral Jen2p was definitively lost just prior to the WGD and is absent in Saccharomyces.
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Affiliation(s)
- Tiziana Lodi
- Dipartimento di Genetica Biologia dei Microrganismi Antropologia Evoluzione, Università di Parma, Parma, Italy.
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27
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Barberio C, Bianchi L, Pinzauti F, Lodi T, Ferrero I, Polsinelli M, Casalone E. Induction and characterization of morphologic mutants in a natural Saccharomyces cerevisiae strain. Can J Microbiol 2007; 53:223-30. [PMID: 17496970 DOI: 10.1139/w06-132] [Citation(s) in RCA: 3] [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: 11/22/2022]
Abstract
Saccharomyces cerevisiae is a good model with which to study the effects of morphologic differentiation on the ecological behaviour of fungi. In this work, 33 morphologic mutants of a natural strain of S. cerevisiae, obtained with UV mutagenesis, were selected for their streak shape and cell shape on rich medium. Two of them, showing both high sporulation proficiency and constitutive pseudohyphal growth, were analysed from a genetic and physiologic point of view. Each mutant carries a recessive monogenic mutation, and the two mutations reside in unlinked genes. Flocculation ability and responsiveness to different stimuli distinguished the two mutants. Growth at 37 degrees C affected the cell but not the colony morphology, suggesting that these two phenotypes are regulated differently. The effect of ethidium bromide, which affects mitochondrial DNA replication, suggested a possible "retrograde action" of mitochondria in pseudohyphal growth.
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Affiliation(s)
- Claudia Barberio
- Department of Animal Biology and Genetics, University of Florence, via Romana 17, I-50125 Firenze, Italy
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28
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Abstract
The original purpose of the experiments described in this article was to identify, in the biotechnologically important yeast Kluyveromyces lactis, gene(s) that are potentially involved in oxidative protein folding within the endoplasmic reticulum (ER), which often represents a bottleneck for heterologous protein production. Because treatment with the membrane-permeable reducing agent dithiothreitol inhibits disulfide bond formation and mimics the reducing effect that the normal transit of folding proteins has in the ER environment, the strategy was to search for genes that conferred higher levels of resistance to dithiothreitol when present in multiple copies. We identified a gene (KNQ1) encoding a drug efflux permease for several toxic compounds that in multiple copies conferred increased dithiothreitol resistance. However, the KNQ1 product is not involved in the excretion of dithiothreitol or in recombinant protein secretion. We generated a knq1 null mutant, and showed that both overexpression and deletion of the KNQ1 gene resulted in increased resistance to dithiothreitol. KNQ1 amplification and deletion resulted in enhanced transcription of iron transport genes, suggesting, for the membrane-associated protein Knq1p, a new, unexpected role in iron homeostasis on which dithiothreitol tolerance may depend.
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Affiliation(s)
- Emmanuela Marchi
- Dipartimento di Genetica, Biologia dei Microrganismi, Antropologia, Evoluzione, University of Parma, Parma, Italy
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29
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Abstract
In Kluyveromyces lactis, galactose transport has been thought to be mediated by the lactose permease encoded by LAC12. In fact, a lac12 mutant unable to grow on lactose did not grow on galactose either and showed low and uninducible galactose uptake activity. The existence of other galactose transport systems, at low and at high affinity, had, however, been hypothesized on the basis of galactose uptake kinetics studies. Here we confirmed the existence of a second galactose transporter and we isolated its structural gene. It turned out to be HGT1, previously identified as encoding the high-affinity glucose carrier. Analysis of galactose transporter mutants, hgt1 and lac12, and the double mutant hgt1lac12, suggested that Hgt1 was the high-affinity and Lac12 was the low-affinity galactose transporter. HGT1 expression was strongly induced by galactose and insensitive to glucose repression. This could explain the rapid adaptation to galactose observed in K. lactis after a shift from glucose to galactose medium.
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Affiliation(s)
- Enrico Baruffini
- Dipartimento di Genetica Antropologia Evoluzione, University of Parma, Parma, Italy
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Saliola M, De Maria I, Lodi T, Fiori A, Falcone C. KlADH3, a gene encoding a mitochondrial alcohol dehydrogenase, affects respiratory metabolism and cytochrome content in Kluyveromyces lactis. FEMS Yeast Res 2007; 6:1184-92. [PMID: 17156015 DOI: 10.1111/j.1567-1364.2006.00103.x] [Citation(s) in RCA: 7] [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: 11/29/2022] Open
Abstract
A Kluyveromyces lactis strain, harbouring KlADH3 as the unique alcohol dehydrogenase (ADH) gene, was used in a genetic screen on allyl alcohol to isolate mutants deregulated in the expression of this gene. Here we report the characterization of some mutants that lacked or had highly reduced amounts of KlAdh3p activity; in addition, these mutants showed alterations in glucose metabolism, reduced respiration and reduced cytochrome content. Our results confirm that the KlAdh3p activity contributes to the reoxidation of cytosolic NAD(P)H feeding the respiratory chain through KlNdi1p, the mitochondrial internal transdehydrogenase. The low levels of KlAdh3p in two of the mutants were associated with mutations in KlSDH1, one of the genes of complex II, suggesting signalling between the respiratory chain and expression of the KlADH3 gene.
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Affiliation(s)
- Michele Saliola
- Dipartimento di Biologia Cellulare e dello Sviluppo, Università di Roma, La Sapienza, Rome, Italy.
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31
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Saliola M, Scappucci G, De Maria I, Lodi T, Mancini P, Falcone C. Deletion of the glucose-6-phosphate dehydrogenase gene KlZWF1 affects both fermentative and respiratory metabolism in Kluyveromyces lactis. Eukaryot Cell 2006; 6:19-27. [PMID: 17085636 PMCID: PMC1800367 DOI: 10.1128/ec.00189-06] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Kluyveromyces lactis, the pentose phosphate pathway is an alternative route for the dissimilation of glucose. The first enzyme of the pathway is the glucose-6-phosphate dehydrogenase (G6PDH), encoded by KlZWF1. We isolated this gene and examined its role. Like ZWF1 of Saccharomyces cerevisiae, KlZWF1 was constitutively expressed, and its deletion led to increased sensitivity to hydrogen peroxide on glucose, but unlike the case for S. cerevisiae, the Klzwf1Delta strain had a reduced biomass yield on fermentative carbon sources as well as on lactate and glycerol. In addition, the reduced yield on glucose was associated with low ethanol production and decreased oxygen consumption, indicating that this gene is required for both fermentation and respiration. On ethanol, however, the mutant showed an increased biomass yield. Moreover, on this substrate, wild-type cells showed an additional band of activity that might correspond to a dimeric form of G6PDH. The partial dimerization of the G6PDH tetramer on ethanol suggested the production of an NADPH excess that was negative for biomass yield.
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Affiliation(s)
- Michele Saliola
- Department of Cell and Developmental Biology, University of Rome La Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy.
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32
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Baruffini E, Lodi T, Dallabona C, Puglisi A, Zeviani M, Ferrero I. Genetic and chemical rescue of the Saccharomyces cerevisiae phenotype induced by mitochondrial DNA polymerase mutations associated with progressive external ophthalmoplegia in humans. Hum Mol Genet 2006; 15:2846-55. [PMID: 16940310 DOI: 10.1093/hmg/ddl219] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [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: 11/13/2022] Open
Abstract
The human POLG gene encodes the catalytic subunit of mitochondrial DNA polymerase gamma (pol gamma). Mutations in pol gamma are associated with a spectrum of disease phenotypes including autosomal dominant and recessive forms of progressive external ophthalmoplegia, spino-cerebellar ataxia and epilepsy, and Alpers-Huttenlocher hepatocerebral poliodystrophy. Multiple deletions, or depletion of mtDNA in affected tissues, are the molecular hallmarks of pol gamma mutations. To shed light on the pathogenic mechanisms leading to these phenotypes, we have introduced in MIP1, the yeast homologue of POLG, two mutations equivalent to the human Y955C and G268A mutations, which are associated with dominant and recessive PEO, respectively. Both mutations induced the generation of petite colonies, carrying either rearranged (rho-) or no (rho0) mtDNA. Mutations in genes that control the mitochondrial supply of deoxynucleotides (dNTP) affect the mtDNA integrity in both humans and yeast. To test whether the manipulation of the dNTP pool can modify the effects of pol gamma mutations in yeast, we have overexpressed a dNTP checkpoint enzyme, ribonucleotide reductase, RNR1, or deleted its inhibitor, SML1. In both mutant strains, the petite mutability was dramatically reduced. The same result was obtained by exposing the mutant strains to dihydrolipoic acid, an anti-oxidant agent. Therefore, an increase of the mitochondrial dNTP pool and/or a decrease of reactive oxygen species can prevent the mtDNA damage induced by pol gamma mutations in yeast and, possibly, in humans.
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Affiliation(s)
- Enrico Baruffini
- Department of Genetics, Biology of Microorganisms, Anthropology, Evolution, University of Parma, Italy
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33
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Ceriani V, Faleschini E, Sarli D, Lodi T, Roncaglia O, Bignami P, Osio C, Somalvico F. Femoral hernia repair. Hernia 2006; 10:169-74. [PMID: 16482402 DOI: 10.1007/s10029-005-0059-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Accepted: 11/30/2005] [Indexed: 10/25/2022]
Abstract
Plug insertion for primary femoral hernia repair may cause p.o. discomfort. The Kugel technique may avoid this problem. Patients' satisfaction to the Kugel and the plug techniques is compared in the present study. Demographics, surgical, outcome and analgesic consumption data of 26 patients treated for with the plug technique (P group) are compared with 24 operated with the Kugel patch (K group). Patients' p.o. discomfort to the two procedures was measured with quantitative (VAS score) and a qualitative (the short form of McGill pain questionnaire, SF-MPQ) methods, and compared. P group presented higher early p.o. pain (P<0.001), higher analgesic consumption and a significative delay in the return to physical activity (P<0.001). SF-MPQ scores at p.o. day 8, day 30 and month 6 were significantly lower for K group (P<0.001, P<0.001, P<0.005). The Kugel technique for femoral hernia treatment seems to cause less p.o. discomfort to patients than the plug technique.
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Affiliation(s)
- V Ceriani
- General Surgery Unit, Policlinico Polispecialistico Multimedica, Sesto San Giovanni, Milan, Italy.
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Lodi T, Bove C, Fontanesi F, Viola AM, Ferrero I. Mutation D104G in ANT1 gene: complementation study in Saccharomyces cerevisiae as a model system. Biochem Biophys Res Commun 2006; 341:810-5. [PMID: 16438935 DOI: 10.1016/j.bbrc.2006.01.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [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] [Received: 01/10/2006] [Accepted: 01/11/2006] [Indexed: 11/24/2022]
Abstract
Mutations in the human ANT1 gene, coding for the ADP/ATP carrier, are responsible for the autosomal dominant and recessive forms of progressive external ophthalmoplegia, mitochondrial disorders characterized by the presence of multiple deletions of mitochondrial DNA in affected tissues. By introducing these mutations at equivalent position in AAC2, the yeast orthologue of ANT1, we created a suitable model for validation of the pathogenicity of the human mutations. Here, we describe the use of this approach in the case of mutations mapping in domains not conserved between human and yeast, taking advantage of a yAAC2/hANT1 chimeric construction as a template to introduce pathogenic hANT1 mutations. Application to the case of the D104G mutation indicated that the chimeric construction could be a tool for validation of pathogenic ANT1 mutations in yeast.
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Affiliation(s)
- Tiziana Lodi
- Department of Genetics Anthropology Evolution, University of Parma, 43100 Parma, Italy.
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Lodi T, Donnini C. Lactose-induced cell death of beta-galactosidase mutants in Kluyveromyces lactis. FEMS Yeast Res 2005; 5:727-34. [PMID: 15851101 DOI: 10.1016/j.femsyr.2005.01.005] [Citation(s) in RCA: 16] [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] [Received: 12/02/2004] [Revised: 01/12/2005] [Accepted: 01/25/2005] [Indexed: 11/30/2022] Open
Abstract
The Kluyveromyces lactis lac4 mutants, lacking the beta-galactosidase gene, cannot assimilate lactose, but grow normally on many other carbon sources. However, when these carbon sources and lactose were simultaneously present in the growth media, the mutants were unable to grow. The effect of lactose was cytotoxic since the addition of lactose to an exponentially-growing culture resulted in 90% loss of viability of the lac4 cells. An osmotic stabilizing agent prevented cells killing, supporting the hypothesis that the lactose toxicity could be mainly due to intracellular osmotic pressure. Deletion of the lactose permease gene, LAC12, abolished the inhibitory effect of lactose and allowed the cell to assimilate other carbon substrates. The lac4 strains gave rise, with unusually high frequency, to spontaneous mutants tolerant to lactose (lar1 mutation: lactose resistant). These mutants were unable to take up lactose. Indeed, lar1 mutation turned out to be allelic to LAC12. The high mutability of the LAC12 locus may be an advantage for survival of K. lactis whose main habitat is lactose-containing niches.
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Affiliation(s)
- Tiziana Lodi
- Dipartimento di Genetica Antropologia Evoluzione, University of Parma, 43100 Parma, Italy.
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Ceriani V, Faleschini E, Bignami P, Lodi T, Roncaglia O, Osio C, Sarli D. Kugel hernia repair: open “mini-invasive” technique. Personal experience on 620 patients. Hernia 2005; 9:344-7. [PMID: 16328156 DOI: 10.1007/s10029-005-0015-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Accepted: 05/10/2005] [Indexed: 10/25/2022]
Abstract
A large monoinstitutional series adopting the Kugel retroparietal technique for inguinal hernia surgery is analysed. Our aim is to assess the "mini-invasiveness" of this technique. Six hundred and twenty patients (pts) affected by monolateral inguinal hernia were treated with a preperitoneal alloplasty with a posterior approach (Kugel hernia repair, KHR) between January 2002 and September 2004. The surgical incision extension was 3.5 cm on average (range 2-4.5). The mean operation time was 33 min (range 20-45). Spinal anaesthesia and ambulatory procedure were applied in 595 cases (96%). Postoperative complications affected 20 pts (3%). The postoperative pain was well controlled. No chronic neuropathic pain was registered at follow-up. Patients resumed work after an average of 9 days (range 7-12) from operation. Recurrence rate was 0.8%. Conclusions. The Kugel hernia repair satisfies the standards to be awarded as a "mini-invasive" technique.
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Affiliation(s)
- V Ceriani
- General Surgery Unit, Policlinico Polispecialistico Multimedica, 20099, Milan, Italy.
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Saliola M, Bartoccioni PC, De Maria I, Lodi T, Falcone C. The deletion of the succinate dehydrogenase gene KlSDH1 in Kluyveromyces lactis does not lead to respiratory deficiency. Eukaryot Cell 2005; 3:589-97. [PMID: 15189981 PMCID: PMC420140 DOI: 10.1128/ec.3.3.589-597.2004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have isolated a Kluyveromyces lactis mutant unable to grow on all respiratory carbon sources with the exception of lactate. Functional complementation of this mutant led to the isolation of KlSDH1, the gene encoding the flavoprotein subunit of the succinate dehydrogenase (SDH) complex, which is essential for the aerobic utilization of carbon sources. Despite the high sequence conservation of the SDH genes in Saccharomyces cerevisiae and K. lactis, they do not have the same relevance in the metabolism of the two yeasts. In fact, unlike SDH1, KlSDH1 was highly expressed under both fermentative and nonfermentative conditions. In addition to this, but in contrast with S. cerevisiae, K. lactis strains lacking KlSDH1 were still able to grow in the presence of lactate. In these mutants, oxygen consumption was one-eighth that of the wild type in the presence of lactate and was normal with glucose and ethanol, indicating that the respiratory chain was fully functional. Northern analysis suggested that alternative pathway(s), which involves pyruvate decarboxylase and the glyoxylate cycle, could overcome the absence of SDH and allow (i) lactate utilization and (ii) the accumulation of succinate instead of ethanol during growth on glucose.
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Affiliation(s)
- Michele Saliola
- Dipartimento di Biologia Cellulare e dello Sviluppo, Università di Roma "La Sapienza" Rome, Italy.
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Abstract
The control of protein conformation during translocation through the endoplasmic reticulum is often a bottleneck for heterologous protein production. The core pathway of the oxidative folding machinery includes two conserved proteins: Pdi1p and Ero1p. We increased the dosage of the genes encoding these proteins in the yeast Kluyveromyces lactis and evaluated the secretion of heterologous proteins. KlERO1, an orthologue of Saccharomyces cerevisiae ERO1, was cloned by functional complementation of the ts phenotype of an Scero1 mutant. The expression of KlERO1 was induced by treatment of the cells with dithiothreitol and by overexpression of human serum albumin (HSA), a disulfide bond-rich protein. Duplication of either PDI1 or ERO1 led to a similar increase in HSA yield. Duplication of both genes accelerated the secretion of HSA and improved cell growth rate and yield. Increasing the dosage of KlERO1 did not affect the production of human interleukin 1beta, a protein that has no disulfide bridges. The results confirm that the ERO1 genes of S. cerevisiae and K. lactis are functionally similar even though portions of their coding sequence are quite different and the phenotypes of mutants overexpressing the genes differ. The marked effects of KlERO1 copy number on the expression of heterologous proteins with a high number of disulfide bridges suggests that control of KlERO1 and KlPDI1 is important for the production of high levels of heterologous proteins of this type.
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Affiliation(s)
- Tiziana Lodi
- Department of Genetics, Anthropology, and Evolution, University of Parma, Parco Area delle Scienze 11/A, I-43100 Parma, Italy
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Palmieri L, Alberio S, Pisano I, Lodi T, Meznaric-Petrusa M, Zidar J, Santoro A, Scarcia P, Fontanesi F, Lamantea E, Ferrero I, Zeviani M. Complete loss-of-function of the heart/muscle-specific adenine nucleotide translocator is associated with mitochondrial myopathy and cardiomyopathy. Hum Mol Genet 2005; 14:3079-88. [PMID: 16155110 DOI: 10.1093/hmg/ddi341] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [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: 11/13/2022] Open
Abstract
Multiple mitochondrial DNA deletions are associated with clinically heterogeneous disorders transmitted as mendelian traits. Dominant missense mutations were found in the gene encoding the heart and skeletal muscle-specific isoform of the adenine nucleotide translocator (ANT1) in families with autosomal dominant progressive external opthalmoplegia and in a sporadic patient. We herein report on a sporadic patient who presented with hypertrophic cardiomyopathy, mild myopathy with exercise intolerance and lactic acidosis but no ophthalmoplegia. A muscle biopsy showed the presence of numerous ragged-red fibers, and Southern blot analysis disclosed multiple deletions of muscle mitochondrial DNA. Molecular analysis revealed a C to A homozygous mutation at nucleotide 368 of the ANT1 gene. The mutation converted a highly conserved alanine into an aspartic acid at codon 123 and was absent in 500 control individuals. This is the first report of a recessive mutation in the ANT1 gene. The clinical and biochemical features are different from those found in dominant ANT1 mutations, resembling those described in ANT1 knockout mice. No ATP uptake was measured in proteoliposomes reconstituted with protein extracts from the patient's muscle. The equivalent mutation in AAC2, the yeast ortholog of human ANT1, resulted in a complete loss of transport activity and in the inability to rescue the severe Oxidative Phosphorylation phenotype displayed by WB-12, an AAC1/AAC2 defective strain. Interestingly, exposure to reactive oxygen species (ROS) scavengers dramatically increased the viability of the WB-12 transformant, suggesting that increased redox stress is involved in the pathogenesis of the disease and that anti-ROS therapy may be beneficial to patients.
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Affiliation(s)
- Luigi Palmieri
- Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari, Italy
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Ceriani V, Bignami P, Faleschini E, Lodi T, Roncaglia O, Osio C, Sarli D. [Intraperitoneal hyperthermic chemotherapy. Preliminary experience with 22 consecutive patients]. Suppl Tumori 2005; 4:S124-5. [PMID: 16437945] [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] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The study analyses the results of surgical treatment and intraperitoneal hyperthermic chemotherapy on a group of 22 patients, affected by peritoneal carcinomatosis of different origins, and treated at Policlinico Multimedica (Milan) between June 2001 and December 2004. Surgical major complications were present in the 23% of the patients, and post-operative mortality rate was 13%. None of the patients presented chemotherapy related toxicity. Six patients died within 2 and 40 months after surgery, while 13 are alive within 4 and 40 months after operation.
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Affiliation(s)
- V Ceriani
- UO Chirurgia Generale, Policlinico Polispecialisticio MultiMedica, Sesto San Giovanni (Mi)
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Ceriani V, Bignami P, Faleschini E, Lodi T, Roncaglia O, Osio C, Sarli D. [D2 gastrectomy in the surgical treatment of gastric cancer]. Suppl Tumori 2005; 4:S92. [PMID: 16437925] [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] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The study is conducted on a series of 57 patients treated with D2 gastrectomy with curative intent for gastric cancer between January 2000 and December 2004, at Policlinico Multimedica (Milan). Postoperative mortality was 2%. Recurrence rate was 10%. The overall survival of the series is 36% at 4 years follow-up. Negative prognostic factors were: high grade tumor, locally advanced primary disease, presence of lymph node metastases, advanced stage of disease and recurrent disease at follow-up. The data of the study are comparable to those in the literature.
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Affiliation(s)
- V Ceriani
- UO Chirurgia Generale, Policlinico Polispecialisticio MultiMedica, Sesto San Giovanni Milano
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Lodi T, Fontanesi F, Ferrero I, Donnini C. Carboxylic acids permeases in yeast: two genes in Kluyveromyces lactis. Gene 2004; 339:111-9. [PMID: 15363851 DOI: 10.1016/j.gene.2004.06.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2004] [Revised: 05/26/2004] [Accepted: 06/10/2004] [Indexed: 10/26/2022]
Abstract
Two new genes KlJEN1 and KlJEN2 were identified in Kluyveromyces lactis. The deduced structure of their products is typical of membrane-bound carriers and displays high similarity to Jen1p, the monocarboxylate permease of Saccharomyces cerevisiae. Both KlJEN1 and KlJEN2 are under the control of glucose repression mediated by FOG1 and FOG2, corresponding to S. cerevisiae GAL83 and SNF1 respectively, and KlCAT8, proteins involved in glucose signalling cascade in K. lactis. KlJEN1, but not KlJEN2, is induced by lactate. KlJEN2 in contrast is expressed at high level in ethanol and succinate. The physiological characterization of null mutants showed that KlJEN1 is the functional homologue of ScJEN1, whereas KlJEN2 encodes a dicarboxylic acids transporter. In fact, KlJen1p [transporter classification (TC) number: 2.A.1.12.2.] is required for lactate uptake and therefore for growth on lactate. KlJen2p is required for succinate transport, as demonstrated by succinate uptake experiments and by inability of Kljen2 mutant to grow on succinate. This carrier appears to transport also malate and fumarate because the Kljen2 mutant cannot grow on these substrates and the succinate uptake is competed by these carboxylic acids. We conclude that KlJEN2 is the first yeast gene shown to encode a dicarboxylic acids permease.
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Affiliation(s)
- Tiziana Lodi
- Dipartimento di Genetica Antropologia Evoluzione, University of Parma, Viale delle Scienze 11/A, 43100 Parma, Italy.
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Fontanesi F, Palmieri L, Scarcia P, Lodi T, Donnini C, Limongelli A, Tiranti V, Zeviani M, Ferrero I, Viola AM. Mutations in AAC2, equivalent to human adPEO-associated ANT1 mutations, lead to defective oxidative phosphorylation in Saccharomyces cerevisiae and affect mitochondrial DNA stability. Hum Mol Genet 2004; 13:923-34. [PMID: 15016764 DOI: 10.1093/hmg/ddh108] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [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: 11/12/2022] Open
Abstract
Autosomal dominant and recessive forms of progressive external ophthalmoplegia (adPEO and arPEO) are mitochondrial disorders characterized by the presence of multiple deletions of mitochondrial DNA in affected tissues. Four adPEO-associated missense mutations have been identified in the ANT1 gene. In order to investigate their functional consequences on cellular physiology, we introduced three of them at equivalent positions in AAC2, the yeast orthologue of human ANT1. We demonstrate here that expression of the equivalent mutations in aac2-defective haploid strains of Saccharomyces cerevisiae results in (a) a marked growth defect on non-fermentable carbon sources, and (b) a concurrent reduction of the amount of mitochondrial cytochromes, cytochrome c oxidase activity and cellular respiration. The efficiency of ATP and ADP transport was variably affected by the different AAC2 mutations. However, irrespective of the absolute level of activity, the AAC2 pathogenic mutants showed a significant defect in ADP versus ATP transport compared with wild-type AAC2. In order to study whether a dominant phenotype, as in humans, could be observed, the aac2 mutant alleles were also inserted in combination with the endogenous wild-type AAC2 gene. The heteroallelic strains behaved as recessive for oxidative growth and petite-negative phenotype. In contrast, reduction in cytochrome content and increased mtDNA instability appeared to behave as dominant traits in heteroallelic strains. Our results indicate that S. cerevisiae is a suitable in vivo model to study the pathogenicity of the human ANT1 mutations and the pathophysiology leading to impairment of oxidative phosphorylation and damage of mtDNA integrity, as found in adPEO.
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Affiliation(s)
- Flavia Fontanesi
- Department of Genetics Anthropology Evolution, University of Parma, 43100 Parma, Italy
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Alberti A, Lodi T, Ferrero I, Donnini C. MIG1-dependent and MIG1-independent regulation of GAL gene expression in Saccharomyces cerevisiae: role of Imp2p. Yeast 2004; 20:1085-96. [PMID: 14558142 DOI: 10.1002/yea.1025] [Citation(s) in RCA: 5] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Imp2p (Yil154c) is a transcriptional activator involved in glucose derepression of the maltose, galactose and raffinose utilization pathways and in resistance to thermal, oxidative or osmotic stress. We analysed the role of Imp2 in the regulation of GAL genes. Imp2 was shown to have a positive effect on glucose derepression of Leloir pathway genes and their activator gene GAL4. The effect of Imp2 on galactose metabolism was shown to be partially dependent on Mig1p. The Mig1-independent role depends on Nrg1p. However, disruption of both MIG1 and NRG1 only partially relieves the glucose repression of GAL genes in the Deltaimp2 mutant, indicating that Imp2 must also have other function(s). Moreover, the interaction between IMP2 and GAL6/BLH1, a recently isolated gene involved in the regulation of GAL genes that shares with Imp2 the ability to protect cells from the glycopeptide bleomycin, was also analysed. The results suggest a major role of Imp2 in a GAL6-independent pathway.
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Affiliation(s)
- Adriana Alberti
- Dipartimento di Genetica Antropologia Evoluzione, Università degli Studi di Parma, Parco Area delle Scienze 11A, 43100 Parma, Italy
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Abstract
The KlLYS2 gene, encoding the alpha-aminoadipate reductase of Kluyveromyces lactis, was isolated by complementation of a lysA1 mutant. The deduced amino acid sequence shared an identity of 73% with the LYS2 product of Saccharomyces cerevisiae. Despite the high sequence homology of the alpha-aminoadipate reductase genes, the two yeast species differently responded to the presence of alpha-aminoadipate in the medium. Wild-type S. cerevisiae is known to be sensitive to alpha-aminoadipate, but becomes resistant when mutated to lys2. In contrast, K. lactis strains were found to be naturally resistant to alpha-aminoadipate. Therefore, the positive selection procedure for the isolation of lys2 mutants on alpha-aminoadipate, as practised in S. cerevisiae, cannot be applied to K. lactis. A possible reason of this difference may be that the catalytic rate of the alpha-aminoadipate reductase differs in the two yeasts. The EMBL/Genbank Accession No. for the KlLYS2 gene is AJ504405.
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Affiliation(s)
- Adriana Alberti
- Dipartimento di Genetica Antropologia Evoluzione, University of Parma, Italy
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Lodi T, Fontanesi F, Guiard B. Co-ordinate regulation of lactate metabolism genes in yeast: the role of the lactate permease gene JEN1. Mol Genet Genomics 2002; 266:838-47. [PMID: 11810259 DOI: 10.1007/s00438-001-0604-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2001] [Accepted: 10/04/2001] [Indexed: 10/27/2022]
Abstract
In the yeast Saccharomyces cerevisiae, the first step in lactate metabolism is its transport across the plasma membrane, a proton symport process mediated by the product of the gene JEN1. Under aerobic conditions, the expression of JEN1 is regulated by the carbon source: the gene is repressed by glucose and induced by non-fermentable substrates. JEN1 expression is also controlled by oxygen availability, but is unaffected by the absence of haem biosynthesis. JEN1 is negatively regulated by the repressors Mig1p and Mig2p, and requires Cat8p for full derepression. In this report we demonstrate that, in addition to these regulators, the Hap2/3/4/5 complex interacts specifically with a CAAT-box element in the JEN1 promoter, and acts to derepress JEN1 expression. We also provide evidence for transcriptional stimulation of JEN1 by the protein kinase Snf1p. Data are presented which provide a better understanding of the molecular mechanisms implicated in the co-regulation of genes involved in the metabolism of lactate.
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Affiliation(s)
- T Lodi
- Istituto di Genetica, Università di Parma, Parco Area delle Scienze 11/A, 43100 Parma, Italy.
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Lodi T, Saliola M, Donnini C, Goffrini P. Three target genes for the transcriptional activator Cat8p of Kluyveromyces lactis: acetyl coenzyme A synthetase genes KlACS1 and KlACS2 and lactate permease gene KlJEN1. J Bacteriol 2001; 183:5257-61. [PMID: 11514507 PMCID: PMC95406 DOI: 10.1128/jb.183.18.5257-5261.2001] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aerobic yeast Kluyveromyces lactis and the predominantly fermentative Saccharomyces cerevisiae share many of the genes encoding the enzymes of carbon and energy metabolism. The physiological features that distinguish the two yeasts appear to result essentially from different organization of regulatory circuits, in particular glucose repression and gluconeogenesis. We have isolated the KlCAT8 gene (a homologue of S. cerevisiae CAT8, encoding a DNA binding protein) as a multicopy suppressor of a fog1 mutation. The Fog1 protein is a homologue of the Snf1 complex components Gal83p, Sip1p, and Sip2p of S. cerevisiae. While CAT8 controls the key enzymes of gluconeogenesis in S. cerevisiae, KlCAT8 of K. lactis does not (I. Georis, J. J. Krijger, K. D. Breunig, and J. Vandenhaute, Mol. Gen. Genet. 264:193-203, 2000). We therefore examined possible targets of KlCat8p. We found that the acetyl coenzyme A synthetase genes, KlACS1 and KlACS2, were specifically regulated by KlCAT8, but very differently from the S. cerevisiae counterparts. KlACS1 was induced by acetate and lactate, while KlACS2 was induced by ethanol, both under the control of KlCAT8. Also, KlJEN1, encoding the lactate-inducible and glucose-repressible lactate permease, was found under a tight control of KlCAT8.
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Affiliation(s)
- T Lodi
- Istituto di Genetica, Parco Area delle Scienze 11-A, Università degli Studi di Parma, 43100 Parma, Italy
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Alberti A, Goffrini P, Ferrero I, Lodi T. Cloning and characterization of the lactate-specific inducible gene KlCYB2, encoding the cytochrome b(2) of Kluyveromyces lactis. Yeast 2000; 16:657-65. [PMID: 10806428 DOI: 10.1002/(sici)1097-0061(200005)16:7<657::aid-yea560>3.0.co;2-%23] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023] Open
Abstract
In yeast the utilization of lactate requires two enzymes, the D and L-lactate ferricytochrome c oxidoreductase (D and L-LCR), which stereospecifically oxidize D- and L-lactate to pyruvate. These enzymes are nuclearly encoded and localized in mitochondria. In the yeast Kluyveromyces lactis, a mutant devoid of D- and L-LCR activities and unable to grow on racemic lactate was isolated. Transformation of the mutant with a K. lactis genomic library allowed the isolation of the KlCYB2 gene, restoring the growth on lactate and the L-LCR activity. The KlCYB2 gene and its flanking regions were sequenced (Accession No. AJ243324; EMBL/GenBank databases). The deduced amino acid sequence is highly homologous to the corresponding Saccharomyces cerevisiae and Hansenula anomala protein sequences previously characterized. The homology is missed in the N-terminal region, corresponding to the presequence cleaved during import into mitochondria. Analysis of KlCYB2 gene expression indicated that, in contrast to S. cerevisiae, the major regulatory feature is induction by lactate.
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Affiliation(s)
- A Alberti
- Istituto di Genetica, Università di Parma, Parma, Italy
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Abstract
In order to keep subscribers up-to-date with the latest developments in their field, this current awareness service is provided by John Wiley & Sons and contains newly-published material on yeasts. Each bibliography is divided into 10 sections. 1 Books, Reviews & Symposia; 2 General; 3 Biochemistry; 4 Biotechnology; 5 Cell Biology; 6 Gene Expression; 7 Genetics; 8 Physiology; 9 Medical Mycology; 10 Recombinant DNA Technology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. (4 weeks journals - search completed 16th Feb 2000)
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Affiliation(s)
- A Alberti
- Istituto di Genetica, Università di Parma, Parma, Italy
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Lodi T, Alberti A, Guiard B, Ferrero I. Regulation of the Saccharomyces cerevisiae DLD1 gene encoding the mitochondrial protein D-lactate ferricytochrome c oxidoreductase by HAP1 and HAP2/3/4/5. Mol Gen Genet 1999; 262:623-32. [PMID: 10628845 DOI: 10.1007/s004380051125] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Expression of the nuclear gene encoding the mitochondrial enzyme D-lactate ferricytochrome c oxidoreductase (D-LCR) was investigated in Saccharomyces cerevisiae. This gene (DLD1) was found to be subject to several regulatory controls at the transcriptional level: synthesis of DLD1 mRNA is repressed by glucose, is derepressed in ethanol or lactate and is heme dependent. We therefore examined the role of the heme-dependent transcriptional activator Hap1p and the carbon source-dependent Hap2/3/4/5 complex. We found that the Hap2/3/4/5 complex and Hap1p have additive effects on the activation of DLD1 transcription: the Hap2/3/4/5 complex is necessary for DLD1 derepression following a shift from fermentable to non-fermentable carbon sources, while the Hap1p effect was independent of the carbon sources tested. An upstream region required for expression and regulation of the DLD1 gene was identified. Within this region the binding sites for both the Hap2/3/4/5 complex and Hap1p were defined by gel retardation experiments and site-directed mutagenesis. Comparison between sequences recognized by Hap1p in different promoters showed that the Hap1p binding site in the DLD1 promoter diverges from the consensus Hap1p binding site.
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Affiliation(s)
- T Lodi
- Istituto di Genetica, Università di Parma, Italy.
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