RESUMO
Oxidative stress and deficiency of the enzyme catalase, which is the primary scavenger of the oxidant H(2)O(2), may contribute to diabetes. The current study examined two polymorphisms in the catalase gene, -262C>nT in the promoter and 111C>T in exon 9, and their effects on blood catalase activity as well as on concentrations of blood glucose, haemoglobin A1c, triglyceride, cholesterol, HDL, LDL, ApoA-I and ApoB. Subjects were type-1 and type-2 diabetics. We evaluated PCR-single strand conformational polymorphism for 111C>T and PCR-restriction fragment length polymorphism for - 262C>T. TT genotype frequency of 111C>T polymorphism was increased in type-1 diabetes. Type-2 diabetics with the CC or CT genotypes had decreased catalase and increased glucose, hemoglobinA1c and ApoB. Type-2 diabetics who have TT genotype in -262C>T may have elevated risk for diabetes complications; these patients had the lowest mean catalase and HDL, as well as the highest glucose, haemoglobin A1c, cholesterol and ApoB.
Assuntos
Catalase/sangue , Catalase/genética , Diabetes Mellitus Tipo 1/enzimologia , Diabetes Mellitus Tipo 2/enzimologia , Adulto , Idoso , Biomarcadores/sangue , Metabolismo dos Carboidratos/genética , Carboidratos/sangue , Estudos de Casos e Controles , Pré-Escolar , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/genética , Feminino , Humanos , Metabolismo dos Lipídeos/genética , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Espécies Reativas de Oxigênio , Adulto JovemRESUMO
Catalase decreases the high, toxic concentrations of hydrogen peroxide but it lets the physiological, low concentrations in the cells mainly for signaling purposes. Its decreased activity may contribute to development of several pathological conditions. Catalase mutations occur frequently in exon 9, these were examined with different, complicated and costly methods. The aim of the current study was to evaluate a method for screening of polymorphisms in catalase exon 9. We used the slab gel electrophoresis of PCR amplicons without denaturation and silver staining for visualization of the DNA bands. We detected extra DNA bands in the 400-800 bp region of the catalase exon 9. Their single stranded nature was proved with nucleotide sequence analyses, comparison with the standard SSCP, staining with Sybr Green II and Sybr Green I, ethidium bromide, no digestion with RFLP (BstX I), and digestion with plant nuclease. We used this method for examination of polymorphisms of catalase exon 9 in microcytic anemia and beta-thalassemia patients. The lowest blood catalase activities were detected in microcytic anemia and beta-thalassemia patients with the TT genotypes of the C111T polymorphism. This method was sensitive for detection of G113A acatalasemia mutation, but poorly detected C37T and G5A acatalasemia mutations.
Assuntos
Anemia/genética , Catalase/genética , Polimorfismo Genético , Análise de Sequência de DNA/métodos , Talassemia beta/genética , Adolescente , Adulto , Anemia/etnologia , Catalase/metabolismo , Éxons , Feminino , Genótipo , Humanos , Hungria , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , Mutação , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição , Polimorfismo Conformacional de Fita Simples , Talassemia beta/etnologiaRESUMO
Catalase is the main regulator of hydrogen peroxide metabolism. In vitiligo patients there are conflicting data on its activity and no data on the effect of -262C>T polymorphism in the catalase gene. Blood catalase activity, -262C>T polymorphism and acatalasemia mutations were examined in 75 vitiligo patients and in 162 controls, in Hungary. We measured blood catalase activity and conducted analyses with PCR-SSCP, polyacrylamide gel electrophoresis and silver staining in combination with RFLP and nucleotide sequencing. Comparison of the wild (CC) genotype and the mutant (TT) genotype in the vitiligo patients revealed a non significant (P > 0.19) increase in blood catalase. Male controls with the CT genotype had significantly (P < 0.04) lower blood catalase activity than CC genotype controls. Female vitiligo patients with CC genotype had lower (P < 0.04) blood catalase than female controls. The frequency of wild genotype (CC) and C alleles is significantly (P < 0.04) decreased in Hungarian controls when compared to controls in Slovenia, Morocco, UK, Greece, Turkey, USA, China. The detection of a novel acatalasemia mutation (37C>T in exon 9) and the 113G>A (exon 9) mutation in Hungary are further proofs of genetic heterogeneity origin of acatalasemia mutations. In conclusion, the -262 C>T polymorphism has a reverse effect on blood catalase in vitiligo patients and in controls. In controls the mutant genotypes and alleles are more frequent in Hungary than in several other populations. The new acatalasemia mutations are further examples of heterogeneity of acatalasemia.
