Made available in DSpace on 2016-08-10T10:39:16Z (GMT). No. of bitstreams: 1 NURIA ALONSO LOPEZ CID.pdf: 1461437 bytes, checksum: 7aabd2e9fb0164bdf7480906eadb35b7 (MD5) Previous issue date: 2016-04-14 / The advances in Anesthesiology took place at the same time as the development of drugs that ensured greater control over pain, patient comfort, and safety during surgical anesthetic procedures. Pharmacogenetics is the science that enables enhanced healthcare, by understanding the genetic variations that may affect the different responses to treatments. CYP3A are the most important enzymes involved in the metabolism of drugs prescribed in clinical practice, showing extensive genetic variability in their expression. CYP3A5 presents the highest number of functional variants, with significant differences in the frequencies observed among different population groups around the world and in Brazil. This study aimed and at assessing the frequency of CYP3A5*3 and CYP3A5*6 genotypic and allelic variants and to estimate the metabolizing profile according to these variants, as well as any potential implications on adverse events with drugs used in anesthesia. The sample used for this study included 166 subjects users of the Laboratório da Área de Saúde da PUCGoiás (PUC Healthcare Laboratory city of Goiás). They were all born in the Brazilian Midwest, over 18 years of age, and from both genders. The blood samples were obtained from each individual and genotyped for CYP3A5*3, A>G (rs 776746) and CYP3A5*6, G>A (rs 10264272) by real time Polymerase Chain Reaction using TaqMan assays. Data analysis of the allelic frequency was conducted by calculating the percentage for the established groups, according to color or race, compared to the total sample. In individuals from the Brazilian Midwest, assessed in this study, the frequency of the allelic variant CYP3A5*3 was 40% and 2% for CYP3A5*6. The frequency observed for the CYP3A5*3 allelic variant in subjects from the Midwest was lower than that from other Brazilian studies and also lower than the frequencies observed in Europeans and Asians, however, they were similar to the frequency seen in populations from East and West Africa. The frequency of the CYP3A5*6 allelic variant, in this study, was higher than that found in European studies and similar of the subjects in the North of Africa. Based on the results, one may infer that 72% would be poor metabolizers. The higher frequency of the poor metabolizer profile shows that there is potential for a greater occurrence of adverse events when using drugs metabolized by CYP3A5 in this population from the Brazilian Midwest. / O progresso da Anestesiologia junto com o desenvolvimento de drogas garantiram maior controle da dor, conforto ao paciente e segurança durante o ato anestésicocirúrgico. A Farmacogenética é uma ciência que permite a melhora da assistência à saúde, por meio do conhecimento das variações genéticas que podem estar envolvidas com as diferenças na resposta terapêutica. As CYP3A são as enzimas mais importantes envolvidas com o metabolismo de drogas prescritas na prática clínica, apresentando grande variabilidade genética na sua expressão. A CYP3A5 é a forma que apresenta mais variantes funcionais e com diferenças expressivas nas frequências observadas em diferentes grupos populacionais do mundo. Este estudo teve como objetivo avaliar a frequência das variantes genotípicas e alélicas do CYP3A5*3 e CYP3A5*6 e inferir sobre o perfil metabolizador dos indivíduos em função destas variantes em relação a drogas usadas em anestesia. O grupo avaliado incluiu 166 indivíduos usuários do Laboratório da Área de Saúde da PUCGoiás, nascidos na região Centro-Oeste do Brasil, maiores de 18 anos e de ambos os sexos. As amostras de sangue foram obtidas de cada indivíduo e genotipados para CYP3A5*3, A>G (rs 776746) and CYP3A5*6, G>A (rs 10264272) por Reação em Cadeia de Polimerase usando sondas TaqMan. A análise dos dados das frequências alélicas foi realizada através do cálculo das porcentagens para os grupos estabelecidos, segundo a cor ou raça, em relação a amostra total. Nos indivíduos da região Centro-Oeste do Brasil avaliados neste estudo, a frequência da variante alélica CYP3A5*3 foi de 40% e da CYP3A5*6 foi de 2%. A frequência observada para a variante alélica CYP3A5*3 em indivíduos da região Centro-Oeste foi menor que a de outros estudos brasileiros e também menor que as frequências verificadas em europeus e asiáticos, porém similar à observada na população do leste e oeste da África. A frequência da variante alélica CYP3A5*6, neste estudo, foi maior que a encontrada em estudos europeus e com valores mais próximos daqueles observados no norte da África. Com base nos resultados obtidos da amostra pode-se inferir que 72% dos indivíduos seriam fracos metabolizadores. A maior frequência do perfil de fraco metabolizador mostra que existe potencial de maior ocorrência de eventos adversos no uso de fármacos metabolizados pela CYP3A5 nesta população da região Centro-Oeste do Brasil.

O NER é uma via de reparo de DNA capaz de lidar com uma ampla variedade de lesões. Participam do NER diversas proteínas, entre elas a endonuclease XPG. Pacientes que possuem mutações no gene XPG apresentam a síndrome XP, e em alguns casos XP/CS. Investigamos a natureza genética de dois pacientes XP-G, que são irmãos e apresentam fenótipo moderado. As células destes pacientes demonstraram alta sensibilidade à luz UVC. Quando expostas a um agente oxidativo, apenas células XP-G/CS exibiram sensibilidade. Identificamos duas mutações missense no gene XPG desses pacientes, e comparamos com outras mutações existentes. Observamos que as mutações possuem um impacto negativo na funcionalidade de XPG. A proteína com a mutação p.Ala28Asp exibiu uma atividade residual em testes de complementação. Os resultados indicam que o fenótipo XP-G desses pacientes é causado por duas mutações missense em heterozigose composta, e que células portadoras dessas alterações exibem respostas diferenciadas frente aos estresses genotóxicos causados pela luz UV e pelo agente oxidativo utilizado. / NER is the most flexible of all known DNA repair mechanisms. XPG is an endonuclease that participates in the final steps of NER. Mutations in this gene may result in the human syndrome XP and, in some cases, in the XP/CS. We investigated the genetic nature in two XP-G patients, siblings and mildly affected. The cells from these patients demonstrated the high UV sensitivity typical of this syndrome. When exposed to an oxidative agent, only XP-G/CS cells exhibited sensitivity. We identified two missense mutations in the XPG gene of these patients, and a comparison with other known mutations is presented. These mutations have a negative impact in the function of XPG. The protein harboring the mutation p.Ala28Asp exhibited residual activity in complementation tests. These results indicate that the phenotype of XP-G patients is caused by two missense mutations in a compound heterozygous manner, and that the cells carrying these alterations exhibit different responses against genotoxic stress caused by the UV light and by the oxidative agent used.

Objective: Mutations in the parkin (PARK2) gene have been associated with autosomal recessive early-onset Parkinson's disease (EOPD) with various frequencies in different populations. The aim of the study is to describe phenotypic characteristics of Czech EOPD patients, to evaluate the influence of environmental risk factors, and to determine the frequency of parkin allelic variants in patients and healthy controls. Methods: A total of 70 EOPD patients (age at onset ≤ 40 years) and 75 controls were phenotyped and screened for the sequence variants and exon rearrangements in the parkin gene. Results: The main features in the phenotype of the patients' sample were: the absence of cognitive deficit, high occurrence of dystonia, depression, hyperhidrosis, an excellent response to dopaminergic therapy, early onset of dyskinesia and motor fluctuation. Patients with mutations in the parkin gene had significantly lower age at onset. The agricultural occupation and work with chemicals increased the risk of EOPD, however the coffee drinking appeared to be a protective factor. Parkin mutations were identified in five patients (7.1%): the p.R334C point mutation was present in one patient, four patients had exon deletions. The detected mutations were observed in the heterozygous state except one homozygous...

O NER é uma via de reparo de DNA capaz de lidar com uma ampla variedade de lesões. Participam do NER diversas proteínas, entre elas a endonuclease XPG. Pacientes que possuem mutações no gene XPG apresentam a síndrome XP, e em alguns casos XP/CS. Investigamos a natureza genética de dois pacientes XP-G, que são irmãos e apresentam fenótipo moderado. As células destes pacientes demonstraram alta sensibilidade à luz UVC. Quando expostas a um agente oxidativo, apenas células XP-G/CS exibiram sensibilidade. Identificamos duas mutações missense no gene XPG desses pacientes, e comparamos com outras mutações existentes. Observamos que as mutações possuem um impacto negativo na funcionalidade de XPG. A proteína com a mutação p.Ala28Asp exibiu uma atividade residual em testes de complementação. Os resultados indicam que o fenótipo XP-G desses pacientes é causado por duas mutações missense em heterozigose composta, e que células portadoras dessas alterações exibem respostas diferenciadas frente aos estresses genotóxicos causados pela luz UV e pelo agente oxidativo utilizado. / NER is the most flexible of all known DNA repair mechanisms. XPG is an endonuclease that participates in the final steps of NER. Mutations in this gene may result in the human syndrome XP and, in some cases, in the XP/CS. We investigated the genetic nature in two XP-G patients, siblings and mildly affected. The cells from these patients demonstrated the high UV sensitivity typical of this syndrome. When exposed to an oxidative agent, only XP-G/CS cells exhibited sensitivity. We identified two missense mutations in the XPG gene of these patients, and a comparison with other known mutations is presented. These mutations have a negative impact in the function of XPG. The protein harboring the mutation p.Ala28Asp exhibited residual activity in complementation tests. These results indicate that the phenotype of XP-G patients is caused by two missense mutations in a compound heterozygous manner, and that the cells carrying these alterations exhibit different responses against genotoxic stress caused by the UV light and by the oxidative agent used.

Objective: Mutations in the parkin (PARK2) gene have been associated with autosomal recessive early-onset Parkinson's disease (EOPD) with various frequencies in different populations. The aim of the study is to describe phenotypic characteristics of Czech EOPD patients, to evaluate the influence of environmental risk factors, and to determine the frequency of parkin allelic variants in patients and healthy controls. Methods: A total of 70 EOPD patients (age at onset ≤ 40 years) and 75 controls were phenotyped and screened for the sequence variants and exon rearrangements in the parkin gene. Results: The main features in the phenotype of the patients' sample were: the absence of cognitive deficit, high occurrence of dystonia, depression, hyperhidrosis, an excellent response to dopaminergic therapy, early onset of dyskinesia and motor fluctuation. Patients with mutations in the parkin gene had significantly lower age at onset. The agricultural occupation and work with chemicals increased the risk of EOPD, however the coffee drinking appeared to be a protective factor. Parkin mutations were identified in five patients (7.1%): the p.R334C point mutation was present in one patient, four patients had exon deletions. The detected mutations were observed in the heterozygous state except one homozygous...

Glutathione transferase (GST) A2-2 is the human enzyme most efficient in catalyzing azathioprine activation. Structure-function relationships were sought explaining the higher catalytic efficiency compared to other alpha class GSTs. By screening a DNA shuffling library, five recombined segments were identified that were conserved among the most active mutants. Mutational analysis confirmed the importance of these short segments as their insertion into low-active GSTs introduced higher azathioprine activity. Besides, H-site mutagenesis led to decreased azathioprine activity when the targeted positions belonged to these conserved segments and mainly enhanced activity when other positions were targeted. Hydrophobic residues were preferred in positions 208 and 213. The prodrug azathioprine is today primarily used for maintaining remission in inflammatory bowel disease. Therapy leads to adverse effects for 30 % of the patients and genotyping of the metabolic genes involved can explain some of these incidences. Five genotypes of human A2-2 were characterized and variant A2*E had 3–4-fold higher catalytic efficiency with azathioprine, due to a proline mutated close to the H-site. Faster activation might lead to different metabolite distributions and possibly more adverse effects. Genotyping of GSTs is recommended for further studies. Molecular docking of azathioprine into a modeled structure of A2*E suggested three positions for mutagenesis. The most active mutants had small or polar residues in the mutated positions. Mutant L107G/L108D/F222H displayed a 70-fold improved catalytic efficiency with azathioprine. Determination of its structure by X-ray crystallography showed a widened H-site, suggesting that the transition state could be accommodated in a mode better suited for catalysis. The mutational analysis increased our understanding of the azathioprine activation in alpha class GSTs and highlighted A2*E as one factor possibly behind the adverse drug-effects. A successfully redesigned GST, with 200-fold enhanced catalytic efficiency towards azathioprine compared to the starting point A2*C, might find use in targeted enzyme-prodrug therapies.