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1.
Hum Mol Genet ; 32(6): 917-933, 2023 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-36190515

RESUMO

Maintaining protein lipoylation is vital for cell metabolism. The H-protein encoded by GCSH has a dual role in protein lipoylation required for bioenergetic enzymes including pyruvate dehydrogenase and 2-ketoglutarate dehydrogenase, and in the one-carbon metabolism through its involvement in glycine cleavage enzyme system, intersecting two vital roles for cell survival. Here, we report six patients with biallelic pathogenic variants in GCSH and a broad clinical spectrum ranging from neonatal fatal glycine encephalopathy to an attenuated phenotype of developmental delay, behavioral problems, limited epilepsy and variable movement problems. The mutational spectrum includes one insertion c.293-2_293-1insT, one deletion c.122_(228 + 1_229-1) del, one duplication of exons 4 and 5, one nonsense variant p.Gln76*and four missense p.His57Arg, p.Pro115Leu and p.Thr148Pro and the previously described p.Met1?. Via functional studies in patient's fibroblasts, molecular modeling, expression analysis in GCSH knockdown COS7 cells and yeast, and in vitro protein studies, we demonstrate for the first time that most variants identified in our cohort produced a hypomorphic effect on both mitochondrial activities, protein lipoylation and glycine metabolism, causing combined deficiency, whereas some missense variants affect primarily one function only. The clinical features of the patients reflect the impact of the GCSH changes on any of the two functions analyzed. Our analysis illustrates the complex interplay of functional and clinical impact when pathogenic variants affect a multifunctional protein involved in two metabolic pathways and emphasizes the value of the functional assays to select the treatment and investigate new personalized options.


Assuntos
Hiperglicinemia não Cetótica , Humanos , Hiperglicinemia não Cetótica/genética , Hiperglicinemia não Cetótica/patologia , Proteínas/genética , Mutação , Éxons/genética , Glicina/genética , Glicina/metabolismo
2.
Clin Exp Rheumatol ; 39 Suppl 130(3): 144-152, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34161225

RESUMO

OBJECTIVES: Evidence from genome-wide and candidate gene association studies, familial aggregation and linkage analyses demonstrate the genetic contribution to fibromyalgia (FM) disease. This study aimed to identify genetic biomarkers of FM and its related comorbid disorders, by exploring 41 polymorphisms potentially involved in FM pathogenesis in families with at least one patient with FM. METHODS: Core symptoms were assessed, and blood samples collected from 556 patients with FM and 395 healthy relatives. For the genetic study, a final sample of 401 FM patients and 232 healthy controls was selected, discarding patients with concomitant pathologies and controls with chronic pain. A family-based approach using DFAM test (Plink) and SNPs (single nucleotide polymorphisms) combination analyses to compare FM patients vs. controls were first applied. Second, the genotypic distribution of subgroups of FM patients, stratified by severe vs. mild symptoms of pain, depression and sleep impairment, was considered. RESULTS: No evidence of associations with FM per se were detected, using either a family-based approach or SNPs combination analyses. However, considering the subgroups of FM patients, the SNP rs6454674 (CNR1, cannabinoid receptor 1 gene) was found as a potential genetic marker of FM correlated with depression (p<.001). CONCLUSIONS: No significant associations using either the family-based analysis or the SNPs combination tests dissociated FM patients and their healthy relatives. FM patients with and without depression showed a significant difference in the genotypic distribution related to the SNP rs6454674 in the cannabinoid receptor 1 gene (CNR1) indicating that FM is not a homogenous disorder.


Assuntos
Fibromialgia , Fibromialgia/diagnóstico , Fibromialgia/genética , Marcadores Genéticos , Genótipo , Humanos , Dor , Polimorfismo de Nucleotídeo Único
3.
Int J Mol Sci ; 22(22)2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34830106

RESUMO

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.


Assuntos
DNA Fúngico , DNA Mitocondrial , Transtornos Heredodegenerativos do Sistema Nervoso , Hepatopatias , Proteínas de Membrana , Mitocôndrias , Doenças Mitocondriais , Proteínas Mitocondriais , Doenças do Sistema Nervoso Periférico , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , DNA Fúngico/genética , DNA Fúngico/metabolismo , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Transtornos Heredodegenerativos do Sistema Nervoso/genética , Transtornos Heredodegenerativos do Sistema Nervoso/metabolismo , Transtornos Heredodegenerativos do Sistema Nervoso/terapia , Humanos , Hepatopatias/genética , Hepatopatias/metabolismo , Hepatopatias/terapia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Doenças Mitocondriais/genética , Doenças Mitocondriais/metabolismo , Doenças Mitocondriais/terapia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Nucleotídeos/genética , Nucleotídeos/metabolismo , Doenças do Sistema Nervoso Periférico/genética , Doenças do Sistema Nervoso Periférico/metabolismo , Doenças do Sistema Nervoso Periférico/terapia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Síndrome
4.
Int J Mol Sci ; 22(9)2021 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-33923309

RESUMO

Mitochondrial diseases result from inherited or spontaneous mutations in mitochondrial or nuclear DNA, leading to an impairment of the oxidative phosphorylation responsible for the synthesis of ATP. To date, there are no effective pharmacological therapies for these pathologies. We performed a yeast-based screening to search for therapeutic drugs to be used for treating mitochondrial diseases associated with dominant mutations in the nuclear ANT1 gene, which encodes for the mitochondrial ADP/ATP carrier. Dominant ANT1 mutations are involved in several degenerative mitochondrial pathologies characterized by the presence of multiple deletions or depletion of mitochondrial DNA in tissues of affected patients. Thanks to the presence in yeast of the AAC2 gene, orthologue of human ANT1, a yeast mutant strain carrying the M114P substitution equivalent to adPEO-associated L98P mutation was created. Five molecules were identified for their ability to suppress the defective respiratory growth phenotype of the haploid aac2M114P. Furthermore, these molecules rescued the mtDNA mutability in the heteroallelic AAC2/aac2M114P strain, which mimics the human heterozygous condition of adPEO patients. The drugs were effective in reducing mtDNA instability also in the heteroallelic strain carrying the R96H mutation equivalent to the more severe de novo dominant missense mutation R80H, suggesting a general therapeutic effect on diseases associated with dominant ANT1 mutations.


Assuntos
Translocador 1 do Nucleotídeo Adenina/genética , Ensaios de Triagem em Larga Escala/métodos , Translocases Mitocondriais de ADP e ATP/genética , Doenças Mitocondriais/tratamento farmacológico , Mutação , Preparações Farmacêuticas/administração & dosagem , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , DNA Mitocondrial/genética , Genes Dominantes , Humanos , Doenças Mitocondriais/genética , Oftalmoplegia/tratamento farmacológico , Oftalmoplegia/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética
5.
Subst Use Misuse ; 54(4): 670-680, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30663487

RESUMO

BACKGROUND: Vulnerability to cannabis use (CU) initiation and problematic use have been shown to be affected by both genetic and environmental factors, with still inconclusive and uncertain evidence. OBJECTIVE: Aim of the present study was to investigate the possible interplay between gene polymorphisms and psychosocial conditions in CU susceptibility. METHODS: Ninety-two cannabis users and ninety-three controls have been included in the study. Exclusion criteria were serious mental health disorders and severe somatic disorders, use of other drugs and alcohol abuse; control subjects were not screened to remove Reward Deficiency Syndrome (RDS) behaviors. A candidate gene association study was performed, including variants related to dopaminergic and endocannabinoids pathways. Adverse childhood experiences and quality of parental care have been retrospectively explored utilizing ACES (Adverse Children Experience Scale), CECA-q (Child Experience of Care and Abuse Questionnaire), PBI (Parental Bonding Instrument). RESULTS: Our findings evidenced a significant association between rs1800497 Taq1A of ANKK1 gene and CU. Parental care was found to be protective factor, with emotional and physical neglect specifically influencing CU. Gender also played a role in CU, with males smoking more than females. However, when tested together genotypes and psychosocial variables, the significance of observed genetic differences disappeared. CONCLUSIONS: Our results confirm a significant role of Taq1A polymorphism in CU vulnerability. A primary role of environmental factors in mediating genetic risk has been highlighted: parental care could be considered the main target to design early prevention programs and strategies.


Assuntos
Maus-Tratos Infantis/psicologia , Fumar Maconha/psicologia , Poder Familiar/psicologia , Proteínas Serina-Treonina Quinases/genética , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Feminino , Estudos de Associação Genética , Humanos , Masculino , Fatores de Proteção , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Inquéritos e Questionários
6.
Am J Hum Genet ; 97(2): 319-28, 2015 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-26189817

RESUMO

Deficiencies in respiratory-chain complexes lead to a variety of clinical phenotypes resulting from inadequate energy production by the mitochondrial oxidative phosphorylation system. Defective expression of mtDNA-encoded genes, caused by mutations in either the mitochondrial or nuclear genome, represents a rapidly growing group of human disorders. By whole-exome sequencing, we identified two unrelated individuals carrying compound heterozygous variants in TRMT5 (tRNA methyltransferase 5). TRMT5 encodes a mitochondrial protein with strong homology to members of the class I-like methyltransferase superfamily. Both affected individuals presented with lactic acidosis and evidence of multiple mitochondrial respiratory-chain-complex deficiencies in skeletal muscle, although the clinical presentation of the two affected subjects was remarkably different; one presented in childhood with failure to thrive and hypertrophic cardiomyopathy, and the other was an adult with a life-long history of exercise intolerance. Mutations in TRMT5 were associated with the hypomodification of a guanosine residue at position 37 (G37) of mitochondrial tRNA; this hypomodification was particularly prominent in skeletal muscle. Deficiency of the G37 modification was also detected in human cells subjected to TRMT5 RNAi. The pathogenicity of the detected variants was further confirmed in a heterologous yeast model and by the rescue of the molecular phenotype after re-expression of wild-type TRMT5 cDNA in cells derived from the affected individuals. Our study highlights the importance of post-transcriptional modification of mitochondrial tRNAs for faithful mitochondrial function.


Assuntos
Doenças Mitocondriais/genética , Modelos Moleculares , Processamento Pós-Transcricional do RNA/genética , RNA de Transferência/genética , tRNA Metiltransferases/genética , Sequência de Aminoácidos , Pareamento de Bases , Sequência de Bases , Exoma/genética , Mutação da Fase de Leitura/genética , Humanos , Doenças Mitocondriais/patologia , Dados de Sequência Molecular , Linhagem , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , tRNA Metiltransferases/química
7.
Nucleic Acids Res ; 43(17): 8368-80, 2015 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-26240381

RESUMO

To gain a wider view of the pathways that regulate mitochondrial function, we combined the effect of heat stress on respiratory capacity with the discovery potential of a genome-wide screen in Saccharomyces cerevisiae. We identified 105 new genes whose deletion impairs respiratory growth at 37°C by interfering with processes such as transcriptional regulation, ubiquitination and cytosolic tRNA wobble uridine modification via 5-methoxycarbonylmethyl-2-thiouridine formation. The latter process, specifically required for efficient decoding of AA-ending codons under stress conditions, was covered by multiple genes belonging to the Elongator (e.g. ELP3) and urmylation (e.g., NCS6) pathways. ELP3 or NCS6 deletants had impaired mitochondrial protein synthesis. Their respiratory deficiency was selectively rescued by overexpression of tRNA(Lys) UUU as well by overexpression of genes (BCK1 and HFM1) with a strong bias for the AAA codon read by this tRNA. These data extend the mitochondrial regulome, demonstrate that heat stress can impair respiration by disturbing cytoplasmic translation of proteins critically involved in mitochondrial function and document, for the first time, the involvement in such process of the Elongator and urmylation pathways. Given the conservation of these pathways, the present findings may pave the way to a better understanding of the human mitochondrial regulome in health and disease.


Assuntos
Histona Acetiltransferases/genética , Mitocôndrias/metabolismo , RNA de Transferência de Lisina/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Estresse Fisiológico/genética , Respiração Celular , Códon , Citocromos/química , Citoplasma/metabolismo , Deleção de Genes , Genoma Fúngico , Temperatura Alta , Mitocôndrias/genética , Mutação , Fosforilação Oxidativa , Fenótipo , RNA de Transferência de Lisina/química , Saccharomyces cerevisiae/metabolismo , Uridina/metabolismo
8.
PLoS Genet ; 10(6): e1004424, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24901367

RESUMO

Identifying the genetic basis for mitochondrial diseases is technically challenging given the size of the mitochondrial proteome and the heterogeneity of disease presentations. Using next-generation exome sequencing, we identified in a patient with severe combined mitochondrial respiratory chain defects and corresponding perturbation in mitochondrial protein synthesis, a homozygous p.Arg323Gln mutation in TRIT1. This gene encodes human tRNA isopentenyltransferase, which is responsible for i6A37 modification of the anticodon loops of a small subset of cytosolic and mitochondrial tRNAs. Deficiency of i6A37 was previously shown in yeast to decrease translational efficiency and fidelity in a codon-specific manner. Modelling of the p.Arg323Gln mutation on the co-crystal structure of the homologous yeast isopentenyltransferase bound to a substrate tRNA, indicates that it is one of a series of adjacent basic side chains that interact with the tRNA backbone of the anticodon stem, somewhat removed from the catalytic center. We show that patient cells bearing the p.Arg323Gln TRIT1 mutation are severely deficient in i6A37 in both cytosolic and mitochondrial tRNAs. Complete complementation of the i6A37 deficiency of both cytosolic and mitochondrial tRNAs was achieved by transduction of patient fibroblasts with wild-type TRIT1. Moreover, we show that a previously-reported pathogenic m.7480A>G mt-tRNASer(UCN) mutation in the anticodon loop sequence A36A37A38 recognised by TRIT1 causes a loss of i6A37 modification. These data demonstrate that deficiencies of i6A37 tRNA modification should be considered a potential mechanism of human disease caused by both nuclear gene and mitochondrial DNA mutations while providing insight into the structure and function of TRIT1 in the modification of cytosolic and mitochondrial tRNAs.


Assuntos
Alquil e Aril Transferases/genética , Doenças Mitocondriais/genética , Sulfurtransferases/genética , Células Cultivadas , Deficiência de Citocromo-c Oxidase/genética , Citosol , DNA Mitocondrial/genética , Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Humanos , Masculino , Mitocôndrias/genética , Biossíntese de Proteínas/genética , RNA/genética , RNA Mitocondrial , RNA de Transferência/genética , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Schizosaccharomyces/enzimologia , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética
9.
Eur Addict Res ; 22(3): 163-75, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26595117

RESUMO

A variety of studies evidenced a relationship between drug use disorders and sexual dysfunction. In particular, heroin and opioid agonist medications to treat heroin dependence have been found to be associated with erectile dysfunction and reduced libido. Controversial findings also indicate the possibility of factors other than the pharmacological effects of opioid drugs concurring to sexual dysfunction. With the present study, we investigated the link between sexual dysfunction and long-term exposure to opioid receptor stimulation (heroin dependence, methadone maintenance treatment, methadone dosage), the potentially related hormonal changes reflecting hypothalamus-pituitary-gonadal axis function and prolactin (PRL) pituitary release, the role of adverse childhood experiences in the clinical history and the concomitant symptoms of comorbid mental health disorders in contributing to sexual problems. Forty male patients participating in a long-term methadone treatment program were included in the present study and compared with 40 healthy control subjects who never used drugs nor abused alcohol. All patients and controls were submitted to the Arizona Sexual Experiences Scale (ASEX), Child Experiences of Care and Abuse-Questionnaire (CECA-Q) and the Symptom Check List-90 Scale. A blood sample for testosterone and PRL assays was collected. Methadone dosages were recorded among heroin-dependent patients on maintenance treatment. Methadone patients scored significantly higher than controls on the 5-item rating ASEX scale, on CECA-Q and on Symptoms Check List 90 (SCL 90) scale. Testosterone plasma levels were significantly lower and PRL levels significantly higher in methadone patients with respect to the healthy control group. ASEX scores reflecting sexual dysfunction were directly and significantly correlated with CECA-Q neglect scores and SCL 90 psychiatric symptoms total score. The linear regression model, when applied only to addicted patients, showed that methadone dosages were not significantly correlated with sexual dysfunction scores except for 'erectile dysfunction', for which an inverse association was evidenced. Testosterone values showed a significant inverse correlation with ASEX sexual dysfunction scores, CECA-Q neglect scores and psychiatric symptom at SCL 90 among methadone patients. PRL levels were directly and significantly correlated with sexual dysfunction scores, psychiatric symptoms at SCL 90 and CECA-Q neglect scores. Both testosterone and PRL did not correlate with methadone dosages. The present findings appear to support the view of childhood adversities and comorbid psychiatric symptoms contributing to sexual dysfunction and related hormonal changes among methadone patients, challenging the assumption that attributes sexual problems entirely to the direct pharmacological effects of opioid agonist medications.


Assuntos
Sobreviventes Adultos de Maus-Tratos Infantis/psicologia , Dependência de Heroína/tratamento farmacológico , Dependência de Heroína/epidemiologia , Transtornos Mentais/epidemiologia , Metadona/efeitos adversos , Tratamento de Substituição de Opiáceos/efeitos adversos , Disfunções Sexuais Fisiológicas/induzido quimicamente , Adulto , Estudos de Casos e Controles , Comorbidade , Diagnóstico Duplo (Psiquiatria) , Dependência de Heroína/sangue , Humanos , Itália/epidemiologia , Masculino , Metadona/uso terapêutico , Prolactina/sangue , Disfunções Sexuais Fisiológicas/sangue , Disfunções Sexuais Fisiológicas/psicologia , Testosterona/sangue , Adulto Jovem
10.
Nat Genet ; 38(5): 570-5, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16582910

RESUMO

The mitochondrial (mt) DNA depletion syndromes (MDDS) are genetic disorders characterized by a severe, tissue-specific decrease of mtDNA copy number, leading to organ failure. There are two main clinical presentations: myopathic (OMIM 609560) and hepatocerebral (OMIM 251880). Known mutant genes, including TK2, SUCLA2, DGUOK and POLG, account for only a fraction of MDDS cases. We found a new locus for hepatocerebral MDDS on chromosome 2p21-23 and prioritized the genes on this locus using a new integrative genomics strategy. One of the top-scoring candidates was the human ortholog of the mouse kidney disease gene Mpv17. We found disease-segregating mutations in three families with hepatocerebral MDDS and demonstrated that, contrary to the alleged peroxisomal localization of the MPV17 gene product, MPV17 is a mitochondrial inner membrane protein, and its absence or malfunction causes oxidative phosphorylation (OXPHOS) failure and mtDNA depletion, not only in affected individuals but also in Mpv17-/- mice.


Assuntos
DNA Mitocondrial/genética , Membranas Intracelulares/metabolismo , Hepatopatias/genética , Proteínas de Membrana/genética , Mitocôndrias/metabolismo , Mutação , Sequência de Aminoácidos , Animais , Células Cultivadas , Cromossomos Humanos Par 2 , Clonagem Molecular , Feminino , Imunofluorescência , Humanos , Masculino , Proteínas de Membrana/química , Camundongos , Dados de Sequência Molecular , Linhagem , Síndrome
11.
Hum Mutat ; 35(8): 983-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24827421

RESUMO

By way of whole-exome sequencing, we identified a homozygous missense mutation in VARS2 in one subject with microcephaly and epilepsy associated with isolated deficiency of the mitochondrial respiratory chain (MRC) complex I and compound heterozygous mutations in TARS2 in two siblings presenting with axial hypotonia and severe psychomotor delay associated with multiple MRC defects. The nucleotide variants segregated within the families, were absent in Single Nucleotide Polymorphism (SNP) databases and are predicted to be deleterious. The amount of VARS2 and TARS2 proteins and valyl-tRNA and threonyl-tRNA levels were decreased in samples of afflicted patients according to the genetic defect. Expression of the corresponding wild-type transcripts in immortalized mutant fibroblasts rescued the biochemical impairment of mitochondrial respiration and yeast modeling of the VARS2 mutation confirmed its pathogenic role. Taken together, these data demonstrate the role of the identified mutations for these mitochondriopathies. Our study reports the first mutations in the VARS2 and TARS2 genes, which encode two mitochondrial aminoacyl-tRNA synthetases, as causes of clinically distinct, early-onset mitochondrial encephalopathies.


Assuntos
Antígenos HLA/genética , Mitocôndrias/genética , Encefalomiopatias Mitocondriais/genética , Mutação , Treonina-tRNA Ligase/genética , Valina-tRNA Ligase/genética , Linhagem Celular , Criança , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Complexo I de Transporte de Elétrons/genética , Complexo I de Transporte de Elétrons/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Antígenos HLA/metabolismo , Heterozigoto , Homozigoto , Humanos , Lactente , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Mitocôndrias/enzimologia , Mitocôndrias/patologia , Encefalomiopatias Mitocondriais/enzimologia , Encefalomiopatias Mitocondriais/patologia , Polimorfismo Genético , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Transferência de Treonina/genética , RNA de Transferência de Treonina/metabolismo , RNA de Transferência de Valina/genética , RNA de Transferência de Valina/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Treonina-tRNA Ligase/metabolismo , Valina-tRNA Ligase/metabolismo
12.
Hum Mutat ; 34(12): 1619-22, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24014394

RESUMO

Mutations in nuclear genes associated with defective complex III (cIII) of the mitochondrial respiratory chain are rare, having been found in only two cIII assembly factors and, as private changes in single families, three cIII structural subunits. Recently, human LYRM7/MZM1L, the ortholog of yeast MZM1, has been identified as a new assembly factor for cIII. In a baby patient with early onset, severe encephalopathy, lactic acidosis and profound, isolated cIII deficiency in skeletal muscle, we identified a disease-segregating homozygous mutation (c.73G>A) in LYRM7/MZM1L, predicting a drastic change in a highly conserved amino-acid residue (p.Asp25Asn). In a mzm1Δ yeast strain, the expression of a mzm1(D25N) mutant allele caused temperature-sensitive respiratory growth defect, decreased oxygen consumption, impaired maturation/stabilization of the Rieske Fe-S protein, and reduced complex III activity and amount. LYRM7/MZM1L is a novel disease gene, causing cIII-defective, early onset, severe mitochondrial encephalopathy.


Assuntos
Acidose Láctica/genética , Acidose Láctica/metabolismo , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Homozigoto , Encefalomiopatias Mitocondriais/genética , Encefalomiopatias Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Chaperonas Moleculares/genética , Mutação , Acidose Láctica/diagnóstico , Sequência de Aminoácidos , Encéfalo/patologia , Análise Mutacional de DNA , Ativação Enzimática , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Encefalomiopatias Mitocondriais/diagnóstico , Proteínas Mitocondriais/química , Chaperonas Moleculares/química , Dados de Sequência Molecular , Linhagem , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Alinhamento de Sequência
13.
Hum Mutat ; 34(11): 1501-9, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23929671

RESUMO

We report three families presenting with hypertrophic cardiomyopathy, lactic acidosis, and multiple defects of mitochondrial respiratory chain (MRC) activities. By direct sequencing of the candidate gene MTO1, encoding the mitochondrial-tRNA modifier 1, or whole exome sequencing analysis, we identified novel missense mutations. All MTO1 mutations were predicted to be deleterious on MTO1 function. Their pathogenic role was experimentally validated in a recombinant yeast model, by assessing oxidative growth, respiratory activity, mitochondrial protein synthesis, and complex IV activity. In one case, we also demonstrated that expression of wt MTO1 could rescue the respiratory defect in mutant fibroblasts. The severity of the yeast respiratory phenotypes partly correlated with the different clinical presentations observed in MTO1 mutant patients, although the clinical outcome was highly variable in patients with the same mutation and seemed also to depend on timely start of pharmacological treatment, centered on the control of lactic acidosis by dichloroacetate. Our results indicate that MTO1 mutations are commonly associated with a presentation of hypertrophic cardiomyopathy, lactic acidosis, and MRC deficiency, and that ad hoc recombinant yeast models represent a useful system to test the pathogenic potential of uncommon variants, and provide insight into their effects on the expression of a biochemical phenotype.


Assuntos
Acidose Láctica/genética , Cardiomiopatia Hipertrófica/genética , Proteínas de Transporte/genética , Complexo de Proteínas da Cadeia de Transporte de Elétrons/deficiência , Mutação , Leveduras/genética , Adolescente , Idade de Início , Sequência de Aminoácidos , Encéfalo/patologia , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Modelos Moleculares , Dados de Sequência Molecular , Linhagem , Conformação Proteica , Proteínas de Ligação a RNA , Alinhamento de Sequência , Leveduras/metabolismo , Adulto Jovem
15.
Hum Mol Genet ; 19(6): 1098-107, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20042463

RESUMO

A peculiar form of hepatocerebral mtDNA depletion syndrome is caused by mutations in the MPV17 gene, which encodes a small hydrophobic protein of unknown function located in the mitochondrial inner membrane. In order to define the molecular basis of MPV17 variants associated with the human disorder, we have previously taken advantage of S. cerevisiae as a model system thanks to the presence of an MPV17 ortholog gene, SYM1. We demonstrate here that the SYM1 gene product is essential to maintain OXPHOS, glycogen storage, mitochondrial morphology and mtDNA stability in stressing conditions such as high temperature and ethanol-dependent growth. To gain insight into the molecular basis of the Sym1-less phenotype, we identified and characterized multicopy suppressor genes and metabolic suppressor compounds. Our results suggest that (i) metabolic impairment and mtDNA instability occur independently from each other as a consequence of SYM1 ablation; (ii) ablation of Sym1 causes depletion of glycogen storage, possibly due to defective anaplerotic flux of tricarboxylic acid (TCA) cycle intermediates to the cytosol; (iii) flattening of mitochondrial cristae in Sym1-defective organelles suggests a role for Sym1 in the structural preservation of the inner mitochondrial membrane, which could in turn control mtDNA maintenance and stability.


Assuntos
Metabolismo Energético , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/química , Proteínas Mitocondriais/metabolismo , Morfogênese , Proteínas de Saccharomyces cerevisiae/metabolismo , Homologia de Sequência de Aminoácidos , Estresse Fisiológico , Alelos , Northern Blotting , Western Blotting , Ciclo do Ácido Cítrico/genética , Dosagem de Genes/genética , Regulação Fúngica da Expressão Gênica , Genes Supressores , Teste de Complementação Genética , Humanos , Proteínas de Membrana/genética , Mitocôndrias/enzimologia , Mitocôndrias/ultraestrutura , Proteínas Mitocondriais/genética , Mutação/genética , Oxirredução , Fenótipo , Regiões Promotoras Genéticas/genética , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/ultraestrutura , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Transcrição Gênica
16.
Eur Arch Psychiatry Clin Neurosci ; 262(1): 47-57, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21773812

RESUMO

Aim of this paper is to investigate the psychobiological reactions to experimentally induced negative emotional states in active marijuana-dependent smokers and whether changes in emotional reactivity were reversed by prolonged abstinence. Twenty-eight patients were randomly included into group A (fourteen active marijuana-dependent smokers) or group B (fourteen abstinent marijuana-dependent subjects). Emotional response evaluation of group B subjects was assessed after 6 months of abstinence. Fourteen healthy volunteers, matched for age and sex, were used as controls. Psychometric and emotional response evaluations were performed by administering Symptoms Check List-90 and State-Trait Anxiety Inventory Y-1 (STAI). Neutral and unpleasant set of pictures selected from the international affective picture system and the Self-Assesment Manikin procedure (SAM) have been used to determine ratings of pleasure and arousal. Before and after the experimental session, blood samples were collected to determine ACTH and cortisol plasma levels. Active cannabis users displayed significantly higher levels of pleasantness SAM scores and lower levels of arousal SAM scores compared to abstinent cannabis users and controls in response to emotional task. In a close parallel with psychological data, hormonal findings indicate a persistent hyperactivity of hypothalamus-pituitary-adrenal (HPA) axis in cannabis users, particularly among active marijuana smokers, and an impaired hormonal reaction to negative emotions, in comparison with healthy subjects. The capacity of the HPA axis to respond to stressful stimuli/negative emotions seems to be only partially recovered after 6 months of abstinence. Ours findings, although obtained in a small number of subjects, suggest an association between active cannabis use, subjective reduced sensitivity to negative emotions and threat and HPA axis dysfunction.


Assuntos
Abuso de Maconha/complicações , Abuso de Maconha/psicologia , Transtornos do Humor/etiologia , Adolescente , Hormônio Adrenocorticotrópico/sangue , Adulto , Análise de Variância , Feminino , Humanos , Hidrocortisona/sangue , Medições Luminescentes , Masculino , Transtornos do Humor/sangue , Transtornos do Humor/diagnóstico , Estimulação Luminosa , Escalas de Graduação Psiquiátrica , Psicometria , Adulto Jovem
17.
Genes (Basel) ; 12(2)2021 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672627

RESUMO

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.


Assuntos
Predisposição Genética para Doença , Doenças Mitocondriais/genética , Modelos Biológicos , Mutação , Leveduras/genética , Núcleo Celular/genética , DNA Mitocondrial , Perfilação da Expressão Gênica , Genes Mitocondriais , Variação Genética , Humanos , Mitocôndrias/genética , Doenças Mitocondriais/metabolismo , Fosforilação Oxidativa , Leveduras/metabolismo
18.
J Clin Med ; 10(21)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34768513

RESUMO

Fibromyalgia (FM) has been explained as a result of gene-environment interactions. The present study aims to verify DNA methylation differences in eleven candidate genome regions previously associated to FM, evaluating DNA methylation patterns as potential disease biomarkers. DNA methylation was analyzed through bisulfite sequencing, comparing 42 FM women and their 42 healthy sisters. The associations between the level of methylation in these regions were further explored through a network analysis. Lastly, a logistic regression model investigated the regions potentially associated with FM, when controlling for sociodemographic variables and depressive symptoms. The analysis highlighted significant differences in the GCSAML region methylation between patients and controls. Moreover, seventeen single CpGs, belonging to other genes, were significantly different, however, only one cytosine related to GCSAML survived the correction for multiple comparisons. The network structure of methylation sites was different for each group; GRM2 methylation represented a central node only for FM patients. Logistic regression revealed that depressive symptoms and DNA methylation in the GRM2 region were significantly associated with FM risk. Our study encourages better exploration of GCSAML and GRM2 functions and their possible role in FM affecting immune, inflammatory response, and central sensitization of pain.

19.
Scand J Pain ; 21(2): 372-383, 2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-34387961

RESUMO

OBJECTIVES: The present pilot study aims to investigate DNA methylation changes of genes related to fibromyalgia (FM) development and its main comorbid symptoms, including sleep impairment, inflammation, depression and other psychiatric disorders. Epigenetic modifications might trigger or perpetuate complex interplay between pain transduction/transmission, central pain processing and experienced stressors in vulnerable individuals. METHODS: We conducted DNA methylation analysis by targeted bisulfite NGS sequencing testing differential methylation in 112 genomic regions from leukocytes of eight women with FM and their eight healthy sisters as controls. RESULTS: Tests for differentially methylated regions and cytosines brought focus on the GRM2 gene, encoding the metabotropic glutamate receptor2. The slightly increased DNA methylation observed in the GRM2 region of FM patients may confirm the involvement of the glutamate pathway in this pathological condition. Logistic regression highlighted the simultaneous association of methylation levels of depression and inflammation-related genes with FM. CONCLUSIONS: Altogether, the results evidence the glutamate pathway involvement in FM and support the idea that a combination of methylated and unmethylated genes could represent a risk factor to FM or its consequence, more than single genes. Further studies on the identified biomarkers could contribute to unravel the causative underlying FM mechanisms, giving reliable directions to research, improving the diagnosis and effective therapies.


Assuntos
Metilação de DNA , Fibromialgia , Receptores de Glutamato Metabotrópico/genética , Depressão/genética , Feminino , Fibromialgia/genética , Humanos , Inflamação/genética , Projetos Piloto
20.
Artigo em Inglês | MEDLINE | ID: mdl-33166669

RESUMO

Both genetic and early environmental factors contribute to the pathogenesis of Alcohol Use Disorder (AUD). Gender and psychopathology symptoms might further moderate this association, resulting in an impairment of both the dopaminergic and serotoninergic pathways that sustain the binge, withdrawal and craving cycle. In a sample of of adult children of alcoholic parents (ACOAs) (n = 107) we compared those with and without an AUD, on socio-demographic variables, adverse childhood experiences, psychopathology symptoms and two polymorphisms associated with an impaired serotoninergic and dopaminergic neurotransmission (5HTTLPR and Taq1A/DRD2). A logistic regression revealed that an early caring environment might lower the risk of developing an AUD. When controlling for the actual psychopathology symptoms, being male and having the genotype associated with an impaired dopaminergic neurotransmission were still associated with AUD. Results were confirmed by an unsupervised approach that showed how the clusters characterised by being male and having the high risk genotypes were still associated with AUD compared to being female without the unfavourable dopamine genotype.Our results point to the need for implementing prevention strategies aimed at creating a caring environment especially in those families with an alcoholic parent. We further suggest that psycho-education as a symptom recognition and avoiding self-medication could improve the outcome in those subjects at higher risk, especially males.


Assuntos
Alcoolismo/etiologia , Filho de Pais com Deficiência/estatística & dados numéricos , Interação Gene-Ambiente , Adulto , Filhos Adultos/psicologia , Filhos Adultos/estatística & dados numéricos , Alcoolismo/epidemiologia , Alcoolismo/genética , Alelos , Estudos de Casos e Controles , Filho de Pais com Deficiência/psicologia , Análise por Conglomerados , Feminino , Predisposição Genética para Doença/genética , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Receptores de Dopamina D2/genética , Fatores de Risco , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Inquéritos e Questionários
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