RESUMO
Recent animal studies have indicated that overexpression of the elongation of long-chain fatty acids family member 6 (Elovl6) gene can cause insulin resistance and ß-cell dysfunction. These are the major factors involved in the development of type 2 diabetes mellitus (T2DM). To identify the relationship between single nucleotide polymorphisms (SNP) of ELOVL6 and T2DM pathogenesis, we conducted a case-control study of 610 Han Chinese individuals (328 newly diagnosed T2DM and 282 healthy subjects). Insulin resistance and islet first-phase secretion function were evaluated by assessment of insulin resistance in a homeostasis model (HOMA-IR) and an arginine stimulation test. Three SNPs of the ELOVL6 gene were genotyped with polymerase chain reaction-restriction fragment length polymorphism, with DNA sequencing used to confirm the results. Only genotypes TT and CT of the ELOVL6 SNP rs12504538 were detected in the samples. Genotype CC was not observed. The T2DM group had a higher frequency of the C allele and the CT genotype than the control group. Subjects with the CT genotype had higher HOMA-IR values than those with the TT genotype. In addition, no statistical significance was observed between the genotype and allele frequencies of the control and T2DM groups for SNPs rs17041272 and rs6824447. The study indicated that the ELOVL6 gene polymorphism rs12504538 is associated with an increased risk of T2DM, because it causes an increase in insulin resistance.
Assuntos
Acetiltransferases/genética , Diabetes Mellitus Tipo 2/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , China/etnologia , Diabetes Mellitus Tipo 2/etnologia , Elongases de Ácidos Graxos , Feminino , Genótipo , Humanos , Resistência à Insulina/genética , Células Secretoras de Insulina/patologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Fragmento de RestriçãoRESUMO
Recent animal studies have indicated that overexpression of the elongation of long-chain fatty acids family member 6 (Elovl6) gene can cause insulin resistance and β-cell dysfunction. These are the major factors involved in the development of type 2 diabetes mellitus (T2DM). To identify the relationship between single nucleotide polymorphisms (SNP) of ELOVL6 and T2DM pathogenesis, we conducted a case-control study of 610 Han Chinese individuals (328 newly diagnosed T2DM and 282 healthy subjects). Insulin resistance and islet first-phase secretion function were evaluated by assessment of insulin resistance in a homeostasis model (HOMA-IR) and an arginine stimulation test. Three SNPs of the ELOVL6 gene were genotyped with polymerase chain reaction-restriction fragment length polymorphism, with DNA sequencing used to confirm the results. Only genotypes TT and CT of the ELOVL6 SNP rs12504538 were detected in the samples. Genotype CC was not observed. The T2DM group had a higher frequency of the C allele and the CT genotype than the control group. Subjects with the CT genotype had higher HOMA-IR values than those with the TT genotype. In addition, no statistical significance was observed between the genotype and allele frequencies of the control and T2DM groups for SNPs rs17041272 and rs6824447. The study indicated that the ELOVL6 gene polymorphism rs12504538 is associated with an increased risk of T2DM, because it causes an increase in insulin resistance.
Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Acetiltransferases/genética , /genética , Polimorfismo de Nucleotídeo Único/genética , China/etnologia , /etnologia , Genótipo , Resistência à Insulina/genética , Células Secretoras de Insulina/patologia , Polimorfismo de Fragmento de RestriçãoRESUMO
A genomic clone encoding manganese-containing superoxide dismutase (SOD; EC 1.15.1.1) was isolated from a Hevea brasiliensis genomic library made in lambda phage EMBL3 by using a heterologous cDNA probe of MnSOD from Nicotiana plumbaginifolia. The nucleotide sequence of 4968 bp from the genomic clone was determined. Based on the putative translation initiation codon and stop codon, PCR primers were designed and utilized for cloning the full-length cDNA from total mRNA. Of the two distinct cDNAs of MnSOD isolated, MnSOD-A has a perfect match with exons of the nuclear gene, while MnSOD-B has a 90.2% homology and is 6 nucleotides longer than MnSOD-A in the putative transit peptide region. The nuclear gene comprises 6 exons and 5 introns, giving a total length of 3211 bp. The sequences of 1400 bp upstream of the initiation codon and 320 bp downstream of the stop codon were also determined. Southern analysis of genomic DNA from Hevea probed with a genomic fragment indicated there are at least two genes of MnSOD in Hevea. Northern blot analysis showed that MnSOD transcripts were present in all tissues examined (leaf, petiole, root, latex, callus) with young leaves showing the highest levels in intact plants. The transcript level in embryogenic callus was nearly 50-fold higher than in mature leaves. In addition, transcripts of MnSOD could be induced 3- to 5-fold in response to sucrose, ethephon and Murashige-Skoog salts.