RESUMO
The coronavirus disease COVID-19 has been the cause of millions of deaths worldwide. Among the SARS-CoV-2 proteins, the non-structural protein 1 (NSP1) has great importance during the virus infection process and is present in both alpha and beta-CoVs. Therefore, monitoring of NSP1 polymorphisms is crucial in order to understand their role during infection and virus-induced pathogenicity. Herein, we analyzed how mutations detected in the circulating SARS-CoV-2 in the population of the city of Manaus, Amazonas state, Brazil could modify the tertiary structure of the NSP1 protein. Three mutations were detected in the SARS-CoV-2 NSP1 gene: deletion of the amino acids KSF from positions 141 to 143 (delKSF), SARS-CoV-2, lineage B.1.195; and two substitutions, R29H and R43C, SARS-CoV-2 lineage B.1.1.28 and B.1.1.33, respectively. The delKSF was found in 47 samples, whereas R29H and R43C were found in two samples, one for each mutation. The NSP1 structures carrying the mutations R43C and R29H on the N-terminal portion (e.g. residues 10 to 127) showed minor backbone divergence compared to the Wuhan model. However, the NSP1 C-terminal region (residues 145 to 180) was severely affected in the delKSF and R29H mutants. The intermediate variable region (residues 144 to 148) leads to changes in the C-terminal region, particularly in the delKSF structure. New investigations must be carried out to analyze how these changes affect NSP1 activity during the infection. Our results reinforce the need for continuous genomic surveillance of SARS-CoV-2 to better understand virus evolution and assess the potential impact of the viral mutations on the approved vaccines and future therapies.
Assuntos
COVID-19/epidemiologia , SARS-CoV-2/genética , Proteínas não Estruturais Virais/genética , Sequência de Aminoácidos/genética , Substituição de Aminoácidos/genética , Brasil/epidemiologia , Humanos , Polimorfismo Genético/genética , Deleção de Sequência/genéticaRESUMO
The COVID-19 pandemic poses serious threats to global health, and the emerging mutation in SARS-CoV-2 genomes is one of the major challenges of disease control. Considering the growth of epidemic curve and the circulating SARS-CoV-2 variants in Brazil, the role of locally prevalent E484K and N501Y substitutions in contributing to the epidemiological outcomes is of public health interest for investigation. We developed a likelihood-based statistical framework to reconstruct reproduction numbers, estimate transmission advantage associated with different SARS-CoV-2 variants regarding the marking (identifying) 484K and 501Y substitutions (including Alpha, Zeta, and Gamma variants) in Brazil, and explored the interactive effects of genetic activities on transmission advantage marked by these two mutations. We found a significant transmission advantage associated with the 484K/501Y variants (including P.1 or Gamma variants), which increased the infectivity significantly by 23%. In contrast and by comparison to Gamma variants, E484K or N501Y (including Alpha or Zeta variants) substitution alone appeared less likely to secure a concrete transmission advantage in Brazil. Our finding indicates that the combined impact of genetic activities on transmission advantage marked by 484K/501Y outperforms their independent contributions in Brazil, which implies an interactive effect in shaping the increase in the infectivity of COVID-19. Future studies are needed to investigate the mechanisms of how E484K and N501Y mutations and the complex genetic mutation activities marked by them in SARS-CoV-2 affect the transmissibility of COVID-19.
Assuntos
Substituição de Aminoácidos/genética , COVID-19/transmissão , COVID-19/virologia , Genoma Viral , Modelos Teóricos , SARS-CoV-2/genética , Brasil/epidemiologia , COVID-19/epidemiologia , Coleta de Dados , Humanos , Funções Verossimilhança , Mutação , Saúde Pública , SARS-CoV-2/patogenicidadeRESUMO
During the first few months of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolution in a new host, contrasting hypotheses have been proposed about the way the virus has evolved and diversified worldwide. The aim of this study was to perform a comprehensive evolutionary analysis to describe the human outbreak and the evolutionary rate of different genomic regions of SARS-CoV-2. The molecular evolution in nine genomic regions of SARS-CoV-2 was analyzed using three different approaches: phylogenetic signal assessment, emergence of amino acid substitutions, and Bayesian evolutionary rate estimation in eight successive fortnights since the virus emergence. All observed phylogenetic signals were very low and tree topologies were in agreement with those signals. However, after 4 months of evolution, it was possible to identify regions revealing an incipient viral lineage formation, despite the low phylogenetic signal since fortnight 3. Finally, the SARS-CoV-2 evolutionary rate for regions nsp3 and S, the ones presenting greater variability, was estimated as 1.37 × 10-3 and 2.19 × 10-3 substitution/site/year, respectively. In conclusion, results from this study about the variable diversity of crucial viral regions and determination of the evolutionary rate are consequently decisive to understand essential features of viral emergence. In turn, findings may allow the first-time characterization of the evolutionary rate of S protein, crucial for vaccine development.
Assuntos
Evolução Biológica , Proteases Semelhantes à Papaína de Coronavírus/genética , Evolução Molecular , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Substituição de Aminoácidos/genética , Animais , COVID-19/patologia , Quirópteros/virologia , Genoma Viral/genética , Humanos , FilogeniaRESUMO
Congenital absence of skin (CAS) is a clinical sign associated with the main types of epidermolysis bullosa (EB). Very few studies have investigated the genetic background that may influence the occurrence of this condition. Our objective was to investigate genotype-phenotype correlations on EB with CAS through a literature revision on the pathogenic variants previously reported. A total of 171 cases (49 EB simplex, EBS; 23 junctional EB, JEB; and 99 dystrophic EB, DEB), associated with 132 pathogenic variants in eight genes, were included in the genotype-phenotype analysis. In EBS, CAS showed to be a recurrent clinical sign in EBS with pyloric atresia (PA) and EBS associated with kelch-like protein 24; CAS was also described in patients with keratins 5/14 alterations, particularly involving severe phenotypes. In JEB, this is a common clinical sign in JEB with PA associated with premature termination codon variants and/or amino acid substitutions located in the extracellular domain of integrin α6ß4 genes. In DEB with CAS, missense variants occurring close to non-collagenous interruptions of the triple-helix domain of collagen VII appear to influence this condition. This study is the largest review of patients with EB and CAS and expands the spectrum of known variants on this phenomenon.
Assuntos
Atresia das Cóanas/genética , Displasia Ectodérmica/genética , Epidermólise Bolhosa Distrófica/genética , Obstrução da Saída Gástrica/genética , Piloro/anormalidades , Anormalidades da Pele/genética , Substituição de Aminoácidos/genética , Atresia das Cóanas/fisiopatologia , Displasia Ectodérmica/fisiopatologia , Epidermólise Bolhosa Distrófica/fisiopatologia , Obstrução da Saída Gástrica/patologia , Estudos de Associação Genética , Genótipo , Humanos , Mutação/genética , Piloro/patologia , Pele/patologia , Anormalidades da Pele/patologiaRESUMO
Objectives Thyroid cancer is the most common endocrine neoplasm in childhood. There are few studies characterizing pediatric population in Colombia. We intend to detail the clinical, histological characteristics, BRAFV600E mutational status and NIS (sodium-iodine symporter) expression of children with papillary thyroid carcinoma (PTC) managed at Hospital de La Misericordia. Methods Medical records of the Department of Pediatric Surgery and Pathology from 2009 to 2018 were scrutinized in search of cases of differentiated thyroid carcinoma. A descriptive analysis was made. Paraffin embedded tumoral tissue was recovered to assess BRAF V600E mutational status by PCR and NIS expression by immunohistochemistry. Results Sixteen patients were selected, 81.2% were girls. Average age of presentation was 11.8 years. Only one patient had previous radiation exposure. Most frequent symptom was cervical adenopathy with a mean time of 29.2 weeks before diagnosis. 93.7% underwent total thyroidectomy and lymphadenectomy. 62.5% were PTC combining both classic and follicular pattern. 6.25% cases had BRAFV600E mutation and 25% showed NIS focal reactivity. Conclusions We found greater female predominance, lower percentage of risk factors described and a high percentage of patients requiring aggressive surgical treatment. We consider important to contemplate thyroid cancer as a differential diagnosis of cervical lymph node enlargement in children. Diagnosis can be challenging in benign and indeterminate categories of the FNA cytology and biomolecular profiles such as BRAF and NIS could be determinant in guiding treatment. More studies with larger sample size, complete genetic analysis, evaluation to iodine response and long term follow up are required.
Assuntos
Proteínas Proto-Oncogênicas B-raf/genética , Simportadores/genética , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide , Adolescente , Idade de Início , Substituição de Aminoácidos/genética , Criança , Colômbia/epidemiologia , Feminino , Regulação Neoplásica da Expressão Gênica , Ácido Glutâmico/genética , Humanos , Incidência , Masculino , Mutação de Sentido Incorreto , Prognóstico , Simportadores/metabolismo , Câncer Papilífero da Tireoide/diagnóstico , Câncer Papilífero da Tireoide/epidemiologia , Câncer Papilífero da Tireoide/genética , Câncer Papilífero da Tireoide/cirurgia , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia/métodos , Tireoidectomia/estatística & dados numéricos , Resultado do Tratamento , Valina/genéticaRESUMO
Senecavirus A (SVA) is an emerging picornavirus that causes vesicular disease (VD) in swine. The virus has been circulating in swine in the United Stated (USA) since at least 1988, however, since 2014 a marked increase in the number of SVA outbreaks has been observed in swine worldwide. The factors that led to the emergence of SVA remain unknown. Evolutionary changes that accumulated in the SVA genome over the years may have contributed to the recent increase in disease incidence. Here we compared full-genome sequences of historical SVA strains (identified before 2010) from the USA and global contemporary SVA strains (identified after 2011). The results from the genetic analysis revealed 6.32â% genetic divergence between historical and contemporary SVA isolates. Selection pressure analysis revealed that the SVA polyprotein is undergoing selection, with four amino acid (aa) residues located in the VP1 (aa 735), 2A (aa 941), 3C (aa 1547) and 3D (aa 1850) coding regions being under positive/diversifying selection. Several aa substitutions were observed in the structural proteins (VP1, VP2 and VP3) of contemporary SVA isolates when compared to historical SVA strains. Some of these aa substitutions led to changes in the surface electrostatic potential of the structural proteins. This work provides important insights into the molecular evolution and epidemiology of SVA.
Assuntos
Doenças Transmissíveis Emergentes , Infecções por Picornaviridae/veterinária , Picornaviridae/genética , Doenças dos Suínos/virologia , Substituição de Aminoácidos/genética , Animais , Doenças Transmissíveis Emergentes/veterinária , Doenças Transmissíveis Emergentes/virologia , Surtos de Doenças , Evolução Molecular , Variação Genética , Genoma Viral , Filogenia , Infecções por Picornaviridae/epidemiologia , Suínos , Doenças dos Suínos/epidemiologia , Estados Unidos/epidemiologia , Proteínas Virais/genética , Proteínas Estruturais Virais/genéticaRESUMO
After sperm-oocyte fusion, cortical granules (CGs) located in oocyte cortex undergo exocytosis and their content is released into the perivitelline space to avoid polyspermy. Thus, cortical granule exocytosis (CGE) is a key process for fertilization success. We have demonstrated that alpha-SNAP -and its functional partner NSF- mediate fusion of CGs with the plasma membrane in mouse oocytes. Here, we examined at cellular and ultrastructural level oocytes from hyh (hydrocephalus with hop gait) mice, which present a missense mutation in the Napa gene that results in the substitution of methionine for isoleucine at position 105 (M105I) of alpha-SNAP. Mutated alpha-SNAP was mislocalized in hyh oocytes while NSF expression increased during oocyte maturation. Staining of CGs showed that 9.8% of hyh oocytes had abnormal localization of CGs and oval shape. Functional tests showed that CGE was impaired in hyh oocytes. Interestingly, in vitro fertilization assays showed a decreased fertilization rate for hyh oocytes. Furthermore, fertilized hyh oocytes presented an increased polyspermy rate compared to wild type ones. At ultrastructural level, hyh oocytes showed small mitochondria and a striking accumulation and secretion of degradative structures. Our findings demonstrate the negative effects of alpha-SNAP M105 mutation on oocyte biology and further confirm the relevance of alpha-SNAP in female fertility.
Assuntos
Infertilidade Feminina/genética , Mutação de Sentido Incorreto , Oócitos/citologia , Oócitos/fisiologia , Oogênese/genética , Proteínas de Ligação a Fator Solúvel Sensível a N-Etilmaleimida/genética , Substituição de Aminoácidos/genética , Animais , Feminino , Fertilidade/genética , Fertilização/genética , Homozigoto , Isoleucina/genética , Masculino , Metáfase/genética , Metionina/genética , Camundongos , Camundongos Transgênicos , Oócitos/ultraestruturaRESUMO
This report presents an efficient protocol of the stable genetic transformation of coffee plants expressing the Cry10Aa protein of Bacillus thuringiensis. Embryogenic cell lines with a high potential of propagation, somatic embryo maturation, and germination were used. Gene expression analysis of cytokinin signaling, homedomains, auxin responsive factor, and the master regulators of somatic embryogenesis genes involved in somatic embryo maturation were evaluated. Plasmid pMDC85 containing the cry10Aa gene was introduced into a Typica cultivar of C. arabica L. by biobalistic transformation. Transformation efficiency of 16.7% was achieved, according to the number of embryogenic aggregates and transgenic lines developed. Stable transformation was proven by hygromycin-resistant embryogenic lines, green fluorescent protein (GFP) expression, quantitative analyses of Cry10Aa by mass spectrometry, Western blot, ELISA, and Southern blot analyses. Cry10Aa showed variable expression levels in somatic embryos and the leaf tissue of transgenic plants, ranging from 76% to 90% of coverage of the protein by mass spectrometry and from 3.25 to 13.88 µg/g fresh tissue, with ELISA. qPCR-based 2-ΔΔCt trials revealed high transcription levels of cry10Aa in somatic embryos and leaf tissue. This is the first report about the stable transformation and expression of the Cry10Aa protein in coffee plants with the potential for controlling the coffee berry borer.
Assuntos
Proteínas de Bactérias/genética , Coffea/genética , Endotoxinas/genética , Proteínas Hemolisinas/genética , Plantas Geneticamente Modificadas , Substituição de Aminoácidos/genética , Animais , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/toxicidade , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/toxicidade , Coffea/fisiologia , Café/genética , Besouros/crescimento & desenvolvimento , Endotoxinas/metabolismo , Endotoxinas/toxicidade , Germinação , Proteínas Hemolisinas/metabolismo , Proteínas Hemolisinas/toxicidade , Técnicas de Embriogênese Somática de Plantas/métodos , Sementes/metabolismo , Transformação GenéticaRESUMO
The ability to predict how mutations affect protein structure, folding, and flexibility can elucidate the molecular mechanisms leading to disruption of supersecondary structures, the emergence of phenotypes, as well guiding rational protein engineering. The advent of fast and accurate computational tools has enabled us to comprehensively explore the landscape of mutation effects on protein structures, prioritizing mutations for rational experimental validation.Here we describe the use of two complementary web-based in silico methods, DUET and DynaMut, developed to infer the effects of mutations on folding, stability, and flexibility and how they can be used to explore and interpret these effects on protein supersecondary structures.
Assuntos
Substituição de Aminoácidos/genética , Biologia Computacional/métodos , Engenharia de Proteínas/métodos , Proteínas/química , Motivos de Aminoácidos , Humanos , Mutação de Sentido Incorreto/genética , Dobramento de Proteína , Estabilidade Proteica , Proteínas/genéticaAssuntos
População Negra/genética , Polimorfismo de Nucleotídeo Único , Sistema do Grupo Sanguíneo Rh-Hr/genética , Alelos , Substituição de Aminoácidos/genética , Anemia Falciforme/sangue , Anemia Falciforme/genética , Anemia Falciforme/imunologia , Doadores de Sangue , Brasil/etnologia , Genótipo , Teste de Histocompatibilidade , Humanos , Masculino , Fenótipo , Sistema do Grupo Sanguíneo Rh-Hr/imunologiaRESUMO
Carnivore protoparvovirus 1 (canine parvovirus 2, CPV-2) has undergone a rapid evolution through mutations in the capsid protein VP2, giving rise to variants associated with unique clinicopathological and immunological features. VP2 is a major capsid protein involved in key steps of virus biology, including interactions with cellular receptors and with the immune system. This study analyzed the complete VP2 coding sequence of 38 CPV-2 isolates obtained from dogs with clinical parvovirosis in southern Brazil. Amplicons encompassing the whole VP2 coding region were subjected to nucleotide sequencing, and predicted amino acid sequences were analyzed to identify molecular markers of viral variants. Viral variants were classified as CPV-2a, -2b or -2c based on the presence of the amino acid Asn, Asp or Glu, respectively, at VP2 residue 426. Amino acid sequence analysis identified 20 CPV-2c and four CPV-2b isolates. Eleven viruses were identified as New CPV-2a, two as New CPV-2b, and one resembled the original CPV-2 and was designated CPV-2-like. In addition to the mutation at amino acid 426 of VP2, new 2a/2b variants containing a Ser297Ala mutation at residue 297 were identified. CPV-2-like samples contained some mutations that were also present in the original CPV-2 isolate, including as Leu, Thr, Ala and Asp at residues 87, 101, 300 and 305, respectively. The New CPV-2a isolates had three additional mutations (Phe267Tyr, Tyr324Ile and Thr440Ala) associated with selective pressure and development of disease in vaccinated dogs. The resemblance of the CPV-2-like isolate to CPV-2 suggests reemergence of CPV-2 and/or evolution from vaccine strains. Phylogenetic analysis grouped the variants with their respective reference strains, in general, according to amino acid changes. These results demonstrate the high VP2 diversity of CPV circulating in dogs in southern Brazil and indicate the emergence of new viral variants that differ markedly from the current vaccine strains.
Assuntos
Proteínas do Capsídeo/genética , Doenças do Cão/virologia , Variação Genética/genética , Infecções por Parvoviridae/veterinária , Parvovirus Canino/genética , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Animais , Sequência de Bases , Brasil , DNA Viral/genética , Cães , Parvovirus Canino/classificação , Parvovirus Canino/isolamento & purificação , Filogenia , Isoformas de Proteínas/genética , Análise de Sequência de DNA , VacinaçãoRESUMO
A neutral evolution model that explicitly considers codons, amino acids, and the degeneracy of the genetic code is developed. The model is built from nucleotides up to amino acids, and it represents a refinement of the neutral theory of molecular evolution. The model is based on a stochastic process that leads to a stationary probability distribution of amino acids. The latter is used as a neutral test of evolution. We provide some examples for assessing the neutrality test for a small set of protein sequences. The Jukes-Cantor model is generalized to deal with amino acids and it is compared with our neutral model, along with the empirical BLOSUM62 substitution model. The neutral test provides a baseline to which the evolution of any protein can be analyzed, and it clearly helps in discerning putative amino acids with unexpected frequencies that might be under positive or negative selection. Our model and neutral test are as universal as the standard genetic code.
Assuntos
Substituição de Aminoácidos , Deriva Genética , Modelos Genéticos , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Evolução Molecular , ProteínasRESUMO
This study's purpose was to identify polymorphisms (SNP) in the goat ß-defensin 1 gene and to associate these SNPs with traits related to nematodean and protozoan infections in Anglo-Nubian goats from semiarid region of Brazil. A total of 184 animals were used for DNA extraction, PCR and DNA automatic sequencing. The association analyses included the fixed effects of animal age, bloodline and genotype of the SNP marker in the statistical model. The means of genotypes were compared by the Fisher test (P < 0.05). Twelve polymorphism genotypes were found: two in intron 1, seven in exon 2 and three in 3' untranslated region. The SNPs of exon 2 were responsible for amino acid substitutions in six genetic codes, and the changes in the 25th and 33rd codes affected the protein function. The SNP 1937 was significantly associated with number of protozoan oocysts, whereas SNP 2001 was associated with degree of anaemia (Famacha©). Polymorphism 2046, in turn, showed a significant association with Famacha© degree and number of protozoan oocysts. SNP 2140 associated with maximum EPG of the animal. Results from this study suggest that the ß-defensin 1 gene can be used as a molecular marker for selection of goats regarding the susceptibility to endoparasites infections.
Assuntos
Cabras/genética , Cabras/parasitologia , Nematoides/classificação , Infecções Protozoárias em Animais/parasitologia , beta-Defensinas/genética , Substituição de Aminoácidos/genética , Animais , Sequência de Bases , Brasil , Fezes/parasitologia , Feminino , Predisposição Genética para Doença/genética , Genótipo , Nematoides/isolamento & purificação , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNARESUMO
BACKGROUND: Eqolisins are rare acid proteases found in archaea, bacteria and fungi. Certain fungi secrete acids as part of their lifestyle and interestingly these also have many eqolisin paralogs, up to nine paralogs have been recorded. This suggests a process of functional redundancy and diversification has occurred, which was the subject of the research we performed and describe here. RESULTS: We identified eqolisin homologs by means of iterative HMMER analysis of the NR database. The identified sequences were scrutinized for which new hallmarks were identified by molecular dynamics simulations of mutants in highly conserved positions, using the structure of an eqolisin that was crystallized in the presence of a transition state inhibitor. Four conserved glycines were shown to be important for functionality. A substitution of W67F is shown to be accompanied by the L105W substitution. Molecular dynamics shows that the W67 binds to the substrate via a π-π stacking and a salt bridge, the latter being stronger in a virtual W67F/L105W double mutant of the resolved structure of Scytalido-carboxyl peptidase-B (PDB ID: 2IFW). Additional problematic mutations are discussed. Upon sequence scrutiny we obtained a set of 233 sequences that was used to reconstruct a Bayesian phylogenetic tree. We identified 14 putative specificity determining positions (SDPs) of which four are explained by mere structural explanations and nine seem to correspond to functional diversification related with substrate binding and specificity. A first sub-network of SDPs is related to substrate specificity whereas the second sub-network seems to affect the dynamics of three loops that are involved in substrate binding. CONCLUSION: The eqolisins form a small superfamily of acid proteases with nevertheless many paralogs in acidic fungi. Functional redundancy has resulted in diversification related to substrate specificity and substrate binding.
Assuntos
Ácido Aspártico Endopeptidases/química , Ácido Aspártico Endopeptidases/metabolismo , Simulação de Dinâmica Molecular , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Ácido Aspártico Endopeptidases/genética , Teorema de Bayes , Sítios de Ligação , Sequência Conservada , Evolução Molecular , Transferência Genética Horizontal/genética , Glicina/química , Modelos Moleculares , Mutação/genética , Filogenia , Estrutura Secundária de Proteína , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade , Especificidade por Substrato , TermodinâmicaRESUMO
Recombinant adeno-associated virus (rAAV) vector platforms have shown considerable therapeutic success in gene therapy for inherited disorders. In cystic fibrosis (CF), administration of first-generation rAAV2 was safe, but clinical benefits were not clearly demonstrated. Therefore, next-generation vectors that overcome rate-limiting steps in rAAV transduction are needed to obtain successful gene therapy for this devastating disease. In this study, we evaluated the effects of single-strand or self-complementary (sc) rAAV vectors containing single or multiple tyrosine-to-phenylalanine (Y-F) mutations in capsid surface-exposed residues on serotypes 2, 8 or 9. For this purpose, CF bronchial epithelial (CFBE) cells were transduced with rAAV vectors, and the transgene expression of enhanced green fluorescence protein (eGFP) was analyzed at different time points. The effects of vectors on the cell viability, host cell cycle and in association with co-adjuvant drugs that modulate intracellular vector trafficking were also investigated. Six rAAV vectors demonstrated greater percentage of eGFP+ cells compared to their counterparts at days 4, 7 and 10 post-transduction: rAAV2 Y(272,444,500,730)F, with 1.95-, 3.5- and 3.06-fold increases; rAAV2 Y(252,272,444,500,704,730)F, with 1.65-, 2.12-, and 2-fold increases; scrAAV2 WT, with 1.69-, 2.68-, and 2.32-fold increases; scrAAV8 Y773F, with 57-, 6.06-, and 7-fold increases; scrAAV9 WT, with 7.47-, 4.64-, and 3.66-fold increases; and scrAAV9 Y446F, with 8.39-, 4.62-, and 4.4-fold increases. At days 15, 20, and 30 post-transduction, these vectors still demonstrated higher transgene expression than transfected cells. Although the percentage of eGFP+ cells reduced during the time-course analysis, the delta mean fluorescence intensity increased. These vectors also led to increased percentage of cells in G1-phase without eliciting any cytotoxicity. Prior administration of bortezomib or genistein did not increase eGFP expression in cells transduced with either rAAV2 Y(272,444,500,730)F or rAAV2 Y(252,272,444,500,704,730)F. In conclusion, self-complementary and tyrosine capsid mutations on rAAV serotypes 2, 8, and 9 led to more efficient transduction than their counterparts in CFBE cells by overcoming the intracellular trafficking and second-strand DNA synthesis limitations.
Assuntos
Fibrose Cística/genética , Dependovirus/genética , Terapia Genética , Vetores Genéticos/genética , Substituição de Aminoácidos/genética , Brônquios/metabolismo , Brônquios/patologia , Brônquios/virologia , Fibrose Cística/patologia , Fibrose Cística/terapia , Fibrose Cística/virologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Células Epiteliais/virologia , Humanos , Mutação , Fenilalanina/genética , Sorogrupo , Transdução Genética/métodos , Tirosina/genéticaRESUMO
Charcot-Marie-Tooth disease (CMT) represents a heterogeneous group of hereditary peripheral neuropathies. We previously reported a CMT locus on chromosome 19q13.3 segregating with the disease in a large Costa Rican family with axonal neuropathy and autosomal recessive pattern of inheritance (CMT2B2). We proposed a homozygous missense variant in the Mediator complex 25 (MED25) gene as causative of the disease. Nevertheless, the fact that no other CMT individuals with MED25 variants were reported to date led us to reevaluate the original family. Using exome sequencing, we now identified a homozygous nonsense variant (p.Gln517ter) in the last exon of an adjacent gene, the polynucleotide kinase 3'-phosphatase (PNKP) gene. It encodes a DNA repair protein recently associated with recessive ataxia with oculomotor apraxia type 4 (AOA4) and microcephaly, seizures, and developmental delay (MCSZ). Subsequently, five unrelated Costa Rican CMT2 subjects initially identified as being heterozygous for the same MED25 variant were found to be also compound heterozygote for PNKP. All were heterozygous for the same variant found homozygous in the large family and a second one previously associated with ataxia (p.Thr408del). Detailed clinical reassessment of the initial family and the new individuals revealed in all an adult-onset slowly progressive CMT2 associated with signs of cerebellar dysfunction such as slurred speech and oculomotor involvement, but neither microcephaly, seizures, nor developmental delay. We propose that PKNP variants are the major causative variant for the CMT2 phenotype in these individuals and that the milder clinical manifestation is due to an allelic effect.
Assuntos
Doença de Charcot-Marie-Tooth/genética , Enzimas Reparadoras do DNA/genética , Complexo Mediador/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Adulto , Substituição de Aminoácidos/genética , Estudos de Casos e Controles , Consanguinidade , Costa Rica , Análise Mutacional de DNA , Enzimas Reparadoras do DNA/química , Família , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Mutação de Sentido Incorreto , Linhagem , Fosfotransferases (Aceptor do Grupo Álcool)/química , Polimorfismo de Nucleotídeo ÚnicoRESUMO
The natural diversification of CTX-M ß-lactamases led to the emergence of Asp240Gly variants in the clinic that confer reduced susceptibility to ceftazidime (CAZ). In this study, we compared the impact of this substitution on CAZ and ceftazidime-avibactam (CZA) MICs against isogenic Escherichia coli strains with different porin deficiencies. Our results show a noticeable increase in CAZ resistance in clones expressing Asp240Gly-harboring CTX-M when combined with OmpF porin deficiency. Kinetic analysis revealed that the kcat/Km for CAZ was 5- to 15-fold higher for all Asp240Gly variants but remained 200- to 725-fold lower than that for cefotaxime (CTX). In vitro selection of CAZ-resistant clones yielded nonsusceptible CTX-M producers (MIC of >16 µg/ml) only after overnight incubation; the addition of avibactam (AVI) decreased MICs to a susceptible range against these variants. In contrast, the use of CZA as a selective agent did not yield resistant clones. AVI inactivated both CTX-M-12 and CTX-M-96, with an apparent inhibition constant comparable to that of SHV-2 and 1,000-fold greater than that of PER-2 and CMY-2, and k2/K for CTX-M-12 was 24- and 35-fold higher than that for CTX-M-96 and CTX-M-15, respectively. Molecular modeling suggests that AVI interacts similarly with CTX-M-96 and CTX-M-15. We conclude that the impact of Asp240Gly in resistance may arise when other mechanisms are also present (i.e., OmpF deficiency). Additionally, CAZ selection could favor the emergence of CAZ-resistant subpopulations. These results define the role of Asp240 and the impact of the -Gly substitution and allow us to hypothesize that the use of CZA is an effective preventive strategy to delay the development of resistance in this family of extended-spectrum ß-lactamases.
Assuntos
Substituição de Aminoácidos/genética , Compostos Azabicíclicos/metabolismo , Ceftazidima/metabolismo , Proteínas de Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Porinas/genética , beta-Lactamases/genética , Compostos Azabicíclicos/farmacologia , Ceftazidima/farmacologia , Combinação de Medicamentos , Farmacorresistência Bacteriana/genética , Proteínas de Escherichia coli/metabolismo , Hidrólise , Testes de Sensibilidade Microbiana , Especificidade por Substrato , beta-Lactamases/metabolismoRESUMO
BACKGROUND: The enzymes butyrylcholinesterase (BuChE) and paraoxonase-1 (PON1) are the primary bioscavenging enzymes in serum and exhibit antioxidant and anti-inflammatory activities. PON1 has been associated with diseases caused by high oxidative stress, whereas BuChE appears to be involved in the pathophysiology of the metabolic syndrome and related disorders. It has been suggested that children from rural communities in Mexico may have a predisposition to develop obesity or type 2 diabetes during adolescence or adulthood. The objective of this study was to determine whether associations exist between the paraoxonase (PONase)/arylesterase (AREase) activity of PON1, its PON1-Q192R and PON1-L55M polymorphisms, and BuChE activity with the nutritional status and lipid profiles in a group of children from rural communities in Mexico. METHODS: A group of 97 boys and girls from a rural community in Mexico were assessed for body mass index, the enzymatic activities of BuChE, PONase, and AREase were measured in serum, and their lipid profiles were determined. Genetic polymorphisms of PON1-L55M and PON1-Q192R were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The children were classified into four groups: thinness, normal weight, overweight, and obese. Of the children studied, 34.4% were overweight and obese. The mean age of the participants was 9.5 years (standard deviation = 1.8). The L allele of the PON1-L55M genotype was the most frequent (83.3%), and the R allele of the PON1-Q192R genotype was the most frequent (61.8%). Overweight and obese children had higher values of BuChE, total cholesterol, triglycerides (TG), and lower high-density lipoprotein (HDL-C) values than children with thinness or normal weight (P = 0.028, P = 0.019, P = 0.004, P = 0.069 and P = 0.021, respectively). The levels of AREase and PONase and the prevalence of PON1-L55M and PON1-Q192R genotypes were similar between groups (P = 0.484 and P = 0.380, respectively). CONCLUSIONS: This study establishes a positive association of BuChE activity with nutritional status and serum TG.
Assuntos
Arildialquilfosfatase/metabolismo , Butirilcolinesterase/metabolismo , Estado Nutricional/fisiologia , Substituição de Aminoácidos/genética , Arildialquilfosfatase/genética , Estudos de Casos e Controles , Criança , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , México , Sobrepeso/sangue , Sobrepeso/genética , Sobrepeso/metabolismo , Obesidade Infantil/sangue , Obesidade Infantil/genética , Obesidade Infantil/metabolismo , Polimorfismo de Fragmento de Restrição , Triglicerídeos/sangueRESUMO
Hemoglobin variants (Hb) result from mutations in globin genes, with amino acid substitution in the polypeptide chain. Among the most common structural variants are HbS, HbC, HbD and HbE. The S hemoglobin gene is a high frequency gene across America and Brazil, where it is more frequent in the Southeast and Northeast. The scope of this article is to investigate the presence of hemoglobin variants in 15 quilombos (fugitive slave communities) of Piaui. The sample was of 1,239 people and hemoglobin was screened by high-performance liquid chromatography (HPLC). A questionnaire was applied related to gender, ethnicity and consanguinity. Of the samples analyzed, 5.4% had AS sickle cell trait, while SS and SC sickle cell anemia showed a rate of 0.8%, with AC, AD and DD hemoglobin. Of the 1,069 Afro-descendants, 84 revealed hemoglobin abnormalities, 34 being male 53 being female. There were 13 consanguineous marriages among the 84 hemoglobin alterations. The study of hemoglobin variants in 15 former quilombo communities in the state of Piaui contributes to their education in health in the aspects of genetic inheritance of hemoglobin, a relevant public health issue, providing input for the implementation of the State Program of Sickle Cell Disease of Piaui.
As hemoglobinas variantes (Hb) decorrem de mutações nos genes da globina. As variantes estruturais mais frequentes são HbS, HbC, HbD e HbE. O gene da hemoglobina S tem frequência elevada na América, enquanto que no Brasil é maior no Sudeste e Nordeste. O presente artigo tem por objetivo investigar a presença de hemoglobinas variantes em 15 comunidades quilombolas do estado do Piauí. Foram analisadas 1.239 amostras, nas quais as hemoglobinas foram triadas pela cromatografia líquida de alta eficiência (HPLC). Aplicou-se questionário referente a gênero, etnia e consanguinidade das populações. Das 1.239 amostras, 5,4% apresentaram o traço falciforme AS, as doenças falciformes SS e SC apareceram em 0,8% do total, nas hemoglobinas AC, AD e DD. Das 1.069 pessoas negras, 84 apresentaram alteração das hemoglobinas; destas, 34 eram do sexo masculino e 53 do feminino. Ocorreu a presença de 13 casamentos consanguíneos dentre as 84 alterações das hemoglobinas. O estudo das hemoglobinas variantes em 15 comunidades remanescentes de quilombos do Piauí contribui para sua educação em saúde frente aos aspectos da herança genética destas proteínas, relevante questão de saúde pública, proporcionando subsídios para a implantação do Programa Estadual da Doença Falciforme do Piauí.
Assuntos
Anemia Falciforme/epidemiologia , Etnicidade/genética , Hemoglobinas/genética , Traço Falciforme/epidemiologia , Substituição de Aminoácidos/genética , Anemia Falciforme/genética , População Negra/genética , Brasil/epidemiologia , Cromatografia Líquida de Alta Pressão/métodos , Consanguinidade , Feminino , Frequência do Gene , Variação Genética , Humanos , Masculino , Prevalência , Traço Falciforme/genética , Inquéritos e QuestionáriosRESUMO
Resumo As hemoglobinas variantes (Hb) decorrem de mutações nos genes da globina. As variantes estruturais mais frequentes são HbS, HbC, HbD e HbE. O gene da hemoglobina S tem frequência elevada na América, enquanto que no Brasil é maior no Sudeste e Nordeste. O presente artigo tem por objetivo investigar a presença de hemoglobinas variantes em 15 comunidades quilombolas do estado do Piauí. Foram analisadas 1.239 amostras, nas quais as hemoglobinas foram triadas pela cromatografia líquida de alta eficiência (HPLC). Aplicou-se questionário referente a gênero, etnia e consanguinidade das populações. Das 1.239 amostras, 5,4% apresentaram o traço falciforme AS, as doenças falciformes SS e SC apareceram em 0,8% do total, nas hemoglobinas AC, AD e DD. Das 1.069 pessoas negras, 84 apresentaram alteração das hemoglobinas; destas, 34 eram do sexo masculino e 53 do feminino. Ocorreu a presença de 13 casamentos consanguíneos dentre as 84 alterações das hemoglobinas. O estudo das hemoglobinas variantes em 15 comunidades remanescentes de quilombos do Piauí contribui para sua educação em saúde frente aos aspectos da herança genética destas proteínas, relevante questão de saúde pública, proporcionando subsídios para a implantação do Programa Estadual da Doença Falciforme do Piauí.
Abstract Hemoglobin variants (Hb) result from mutations in globin genes, with amino acid substitution in the polypeptide chain. Among the most common structural variants are HbS, HbC, HbD and HbE. The S hemoglobin gene is a high frequency gene across America and Brazil, where it is more frequent in the Southeast and Northeast. The scope of this article is to investigate the presence of hemoglobin variants in 15 quilombos (fugitive slave communities) of Piaui. The sample was of 1,239 people and hemoglobin was screened by high-performance liquid chromatography (HPLC). A questionnaire was applied related to gender, ethnicity and consanguinity. Of the samples analyzed, 5.4% had AS sickle cell trait, while SS and SC sickle cell anemia showed a rate of 0.8%, with AC, AD and DD hemoglobin. Of the 1,069 Afro-descendants, 84 revealed hemoglobin abnormalities, 34 being male 53 being female. There were 13 consanguineous marriages among the 84 hemoglobin alterations. The study of hemoglobin variants in 15 former quilombo communities in the state of Piaui contributes to their education in health in the aspects of genetic inheritance of hemoglobin, a relevant public health issue, providing input for the implementation of the State Program of Sickle Cell Disease of Piaui.