RESUMO
Abstract Introduction: Multiple Endocrine Neoplasia type 1 (MEN1) is an autosomal dominant inherited disease with an estimated prevalence of 2-10:100 000. The main locations of tumors are parathyroid glands (HPT), gas troenteropancreatic tract (GEPT), and anterior pituitary gland (PT). The aim of our investigation was to describe the phe notype and genotype of Argentinian patients with MEN1. Methods: A total of 68 index patients diagnosed with at least two of the three main tumors or one tumor and a relative with MEN1, and 84 first-degree relatives were studied. We sequenced the coding region (exons 2-10); the promoter, exon 1; and the flanking intronic regions of the MEN1 gene, following the Sanger method. We used MLPA in index patients without mutation. Results: Prevalence of tumors: HPT 87.5%, GEPT 49% (p< 0.001). No statistical differences in the prevalence of HPT vs. PT (68%). Prevalence of pathogenic variants: 90% in familial cases and 51% in sporadic cases. Of the different 36 pathogenic variants, 13 (36.2%) were frameshift micro-rearrangement, 8 (22.2%) were mis sense, 9 (25%) were nonsense, 3 (8.3%) were mutations in splicing sites, 2 (5.5%) were large deletions and, 1 in-frame micro-rearrangement. We found 7 novel pathogenic variants. Thirty-nine percent (n = 33) of first-degree relatives of 23 families were found to be mutation carriers. Conclusion: The phenotype and genotype of Argen tinian patients was similar to other MEN1 populations. A high frequency of PT and the identification of seven novel mutations are underscored.
Resumen Introducción: La neoplasia endocrina múltiple tipo 1 (NEM1) es una enfermedad hereditaria autosómica dominante con una prevalencia estimada de 2-10:100 000. Las localizaciones principales de los tumores son glándulas paratiroides (HPT), tracto gastroenteropan creático (TGEP) y glándula pituitaria (TP). El objetivo de nuestra investigación fue describir el fenotipo y genotipo de pacientes argentinos con NEM1. Métodos: Estudiamos 68 casos índices diagnostica dos por presentar al menos dos de los tres tumores principales, o un tumor y un pariente con NEM1, y 84 familiares de primer grado. Secuenciamos la región codificante (exones 2-10); el promotor, exón 1; y las re giones intrónicas flanqueantes del gen MEN1 siguiendo el método de Sanger. Utilizamos MLPA en pacientes índice sin mutación. Resultados: Prevalencia de tumores: HPT 87.5%, TGEP 49% (p < 0.001), sin diferencias estadísticas entre las prevalencias de HPT vs TP (68%). Prevalencia de variantes patogénicas: 90% en casos familiares y 51% en esporádi cos. Hallamos 36 variantes patogénicas, 7 (20%) fueron noveles. Fueron 13 (36.2%) microarreglos con cambio en el marco de lectura, 9 (25%) variantes sin sentido, 8 (22.2%) con cambio de sentido, 3 (8.3%) en sitio de unión de empalme, 2 (5.5%) grandes deleciones y 1 microarre glo sin cambio en el marco de lectura. El 39 % (n = 33) de los parientes de primer grado en 23 familias fueron portadores de mutaciones. Conclusión: El fenotipo y genotipo de los pacientes argentinos con NEM1 fue similar al de otras poblaciones. Destacamos una alta frecuencia de TP y de variaciones patogénicas noveles.
RESUMO
INTRODUCTION: Multiple Endocrine Neoplasia type 1 (MEN1) is an autosomal dominant inherited disease with an estimated prevalence of 2-10:100 000. The main locations of tumors are parathyroid glands (HPT), gastroenteropancreatic tract (GEPT), and anterior pituitary gland (PT). The aim of our investigation was to describe the phenotype and genotype of Argentinian patients with MEN1. METHODS: A total of 68 index patients diagnosed with at least two of the three main tumors or one tumor and a relative with MEN1, and 84 first-degree relatives were studied. We sequenced the coding region (exons 2-10); the promoter, exon 1; and the flanking intronic regions of the MEN1 gene, following the Sanger method. We used MLPA in index patients without mutation. RESULTS: Prevalence of tumors: HPT 87.5%, GEPT 49% (p< 0.001). No statistical differences in the prevalence of HPT vs. PT (68%). Prevalence of pathogenic variants: 90% in familial cases and 51% in sporadic cases. Of the different 36 pathogenic variants, 13 (36.2%) were frameshift micro-rearrangement, 8 (22.2%) were missense, 9 (25%) were nonsense, 3 (8.3%) were mutations in splicing sites, 2 (5.5%) were large deletions and, 1 in-frame micro-rearrangement. We found 7 novel pathogenic variants. Thirty-nine percent (n = 33) of first-degree relatives of 23 families were found to be mutation carriers. CONCLUSION: The phenotype and genotype of Argentinian patients was similar to other MEN1 populations. A high frequency of PT and the identification of seven novel mutations are underscored.
Introducción: La neoplasia endocrina múltiple tipo 1 (NEM1) es una enfermedad hereditaria autosómica dominante con una prevalencia estimada de 2-10:100 000. Las localizaciones principales de los tumores son glándulas paratiroides (HPT), tracto gastroenteropancreático (TGEP) y glándula pituitaria (TP). El objetivo de nuestra investigación fue describir el fenotipo y genotipo de pacientes argentinos con NEM1. Métodos: Estudiamos 68 casos índices diagnosticados por presentar al menos dos de los tres tumores principales, o un tumor y un pariente con NEM1, y 84 familiares de primer grado. Secuenciamos la región codificante (exones 2-10); el promotor, exón 1; y las regiones intrónicas flanqueantes del gen MEN1 siguiendo el método de Sanger. Utilizamos MLPA en pacientes índice sin mutación. Resultados: Prevalencia de tumores: HPT 87.5%, TGEP 49% (p < 0.001), sin diferencias estadísticas entre las prevalencias de HPT vs TP (68%). Prevalencia de variantes patogénicas: 90% en casos familiares y 51% en esporádicos. Hallamos 36 variantes patogénicas, 7 (20%) fueron noveles. Fueron 13 (36.2%) microarreglos con cambio en el marco de lectura, 9 (25%) variantes sin sentido, 8 (22.2%) con cambio de sentido, 3 (8.3%) en sitio de unión de empalme, 2 (5.5%) grandes deleciones y 1 microarreglo sin cambio en el marco de lectura. El 39 % (n = 33) de los parientes de primer grado en 23 familias fueron portadores de mutaciones. Conclusión: El fenotipo y genotipo de los pacientes argentinos con NEM1 fue similar al de otras poblaciones. Destacamos una alta frecuencia de TP y de variaciones patogénicas noveles.
Assuntos
Genótipo , Neoplasia Endócrina Múltipla Tipo 1 , Fenótipo , Humanos , Argentina/epidemiologia , Masculino , Neoplasia Endócrina Múltipla Tipo 1/genética , Neoplasia Endócrina Múltipla Tipo 1/epidemiologia , Feminino , Adulto , Pessoa de Meia-Idade , Adolescente , Adulto Jovem , Criança , Idoso , Mutação , Pré-Escolar , Neoplasias das Paratireoides/genética , Neoplasias das Paratireoides/epidemiologia , Proteínas Proto-OncogênicasRESUMO
The human transcriptome comprises a myriad of non protein-coding RNA species, including long noncoding RNAs (lncRNAs), which have a remarkable role in transcriptional and epigenetic regulation. We hypothesized that variants in lncRNAs influence the susceptibility to nonalcoholic fatty liver disease (NAFLD). Using next generation sequencing, we performed a survey of genetic variation associated with randomly selected lncRNA-genomic regions located within both experimentally validated and computationally predicted regulatory elements. We used a two-stage (exploratory, n = 96 and replication, n = 390) case-control approach that included well-characterized patients with NAFLD diagnosed by liver biopsy. We sequenced > 263 megabase pairs at quality score > Q17, in a total of 2,027,565 reads, including 170 lncRNA-genomic regions. In the sequencing analysis and the validated dataset, we found that the rs2829145 A/G located in a lncRNA (lnc-JAM2-6) was associated with NAFLD and the disease severity. Prediction of regulatory elements in lnc-JAM2-6 showed potential sequence-specific binding motifs of oncogenes MAFK and JUND, and the transcription factor CEBPB that is involved in inflammatory response. The A-allele was significantly associated with NAFLD as disease trait (p = 0.0081) and the disease severity (NASH-nonalcoholic steatohepatitis vs controls: OR 2.36 [95% CI: 1.54-3.62], p = 0.000078). The A-allele carriers also have significantly higher body mass index and glucose-related traits compared with homozygous GG. Hence, our results suggest that variation in lncRNAs contributes to NAFLD severity, while pointing toward the complexity of the genetic component of NAFLD, which involves still unexplored regulatory regions of the genome.
Assuntos
Hepatopatia Gordurosa não Alcoólica/genética , RNA Longo não Codificante/genética , Epigênese Genética , Feminino , Expressão Gênica , Predisposição Genética para Doença , Variação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/patologiaRESUMO
La epigenética puede definirse como los cambios estables y heredables en la expresión génica, que no son producidos por cambios en la secuencia del ADN. Las modificaciones epigenéticas más estudiadas son la metilación del ADN y las modificaciones postraduccionales de histonas. Estas podrían explicar cómo factores ambientales, nutricionales y otros, contribuyen a la modulación de la expresión de genes y al desarrollo de distintas enfermedades. El síndrome metabólico está definido por la presencia de obesidad, fundamentalmente central, hipertensión, diabetes, dislipemia, y un estado protrombótico y proinflamatorio, que son factores de riesgo de enfermedad cardiovascular. La genética de estas enfermedades es compleja, y es sabido que tanto factores genéticos de susceptibilidad o resistencia, como factores ambientales contribuyen al desarrollo de este síndrome. Nuestro grupo ha estudiado la participación de las modificaciones epigenéticas en la fisio¡patología del síndrome metabólico. Ellas podrían tener un rol importante no solo en el desarrollo de estas enfermedades en la vida adulta, sino predisponer al individuo desde desarrollo prenatal. En esta revisión describimos las principales modificaciones epigenéticas, y a través de nuestros hallazgos cómo sería su papel en el desarrollo del síndrome metabólico. Conocer cómo participarían las modificaciones epigenéticas en estas enfermedades, no solo permitirá mejorar el tratamiento de las mismas, sino establecer medidas preventivas desde la gestación. Rev Argent Endocrinol Metab 52:35-44, 2015 Los autores declaran no poseer conflictos de interés.(AU)
Epigenetics can be defined as stable and heritable changes in gene expression that are not produced by changes in DNA sequence. The most studied epigenetic modifications are DNA methylation and histone post-translational modifications. Epigenetic modifications might explain how environmental, nutritional and others factors contribute to the modulation of gene expression and the development of different diseases. Metabolic syndrome is defined by the presence of mainly central obesity, hypertension, diabetes, dyslipidemia, and a prothrombotic and proinflammatory state, which are risk factors for cardiovascular disease. The genetic factors of these diseases are complex, and it is known that genetic susceptibility or resistance backgrounds as well as environmental factors contribute to the development of this syndrome. We have studied the in¡volvement of epigenetic modifications in the pathophysiology of metabolic syndrome. These modifications might play an important role in the development of these diseases in adulthood, and according to our results, they might also predispose an individual from prenatal life. In this review, we describe the main epigenetic modifications, and which could be their role in the development of metabolic syndrome. Understanding how epigenetic modifications act in these diseases could not only help to identify new avenues of treatment but also to establish preventive measures from gestation. Rev Argent Endocrinol Metab 52:35-44, 2015 No financial conflicts of interest exist.(AU)
RESUMO
La epigenética puede definirse como los cambios estables y heredables en la expresión génica, que no son producidos por cambios en la secuencia del ADN. Las modificaciones epigenéticas más estudiadas son la metilación del ADN y las modificaciones postraduccionales de histonas. Estas podrían explicar cómo factores ambientales, nutricionales y otros, contribuyen a la modulación de la expresión de genes y al desarrollo de distintas enfermedades. El síndrome metabólico está definido por la presencia de obesidad, fundamentalmente central, hipertensión, diabetes, dislipemia, y un estado protrombótico y proinflamatorio, que son factores de riesgo de enfermedad cardiovascular. La genética de estas enfermedades es compleja, y es sabido que tanto factores genéticos de susceptibilidad o resistencia, como factores ambientales contribuyen al desarrollo de este síndrome. Nuestro grupo ha estudiado la participación de las modificaciones epigenéticas en la fisiopatología del síndrome metabólico. Ellas podrían tener un rol importante no solo en el desarrollo de estas enfermedades en la vida adulta, sino predisponer al individuo desde desarrollo prenatal. En esta revisión describimos las principales modificaciones epigenéticas, y a través de nuestros hallazgos cómo sería su papel en el desarrollo del síndrome metabólico. Conocer cómo participarían las modificaciones epigenéticas en estas enfermedades, no solo permitirá mejorar el tratamiento de las mismas, sino establecer medidas preventivas desde la gestación. Rev Argent Endocrinol Metab 52:35-44, 2015 Los autores declaran no poseer conflictos de interés.
Epigenetics can be defined as stable and heritable changes in gene expression that are not produced by changes in DNA sequence. The most studied epigenetic modifications are DNA methylation and histone post-translational modifications. Epigenetic modifications might explain how environmental, nutritional and others factors contribute to the modulation of gene expression and the development of different diseases. Metabolic syndrome is defined by the presence of mainly central obesity, hypertension, diabetes, dyslipidemia, and a prothrombotic and proinflammatory state, which are risk factors for cardiovascular disease. The genetic factors of these diseases are complex, and it is known that genetic susceptibility or resistance backgrounds as well as environmental factors contribute to the development of this syndrome. We have studied the involvement of epigenetic modifications in the pathophysiology of metabolic syndrome. These modifications might play an important role in the development of these diseases in adulthood, and according to our results, they might also predispose an individual from prenatal life. In this review, we describe the main epigenetic modifications, and which could be their role in the development of metabolic syndrome. Understanding how epigenetic modifications act in these diseases could not only help to identify new avenues of treatment but also to establish preventive measures from gestation. Rev Argent Endocrinol Metab 52:35-44, 2015 No financial conflicts of interest exist.
RESUMO
UNLABELLED: We explored the role of transmembrane 6 superfamily member 2 (TM6SF2) rs58542926 C/T nonsynonymous (p.Glu167Lys) variant in genetic susceptibility to nonalcoholic fatty liver disease (NAFLD) and disease severity. A total of 361 individuals (135 control subjects and 226 patients with histologically proven NAFLD) were included in a sample with 97% power for the additive genetic model. A discrete trait analysis of NAFLD showed that rs58542926 was associated with a modest risk of fatty liver (P = 0.038; odds ratio [OR]: 1.37; 95% confidence interval [CI]: 1.02-1.84); nevertheless, conditioning on patatin-like phospholipase domain-containing 3 (PNPLA3)-rs738409 abolished this effect. We did not observe an interaction between rs738409 and rs58542926 variants on the risk of NAFLD. We observed a significant association of rs58542926 and disease severity (P = 0.027), but not lobular inflammation or fibrosis; rs58542926 was not associated with levels of liver enzymes. An allelic test showed that the T (Lys167) allele was significantly associated with disease progression (P = 0.021; OR, 1.66; 95% CI: 1.08-2.55). A significant association was found with the histological degree of liver steatosis (ß, 0.15; standard error: 0.06; P = 0.0299) that was independent of rs738409. Homozygous carriers of the C (Glu167) allele showed increased risk for cardiovascular disease. TM6SF2 protein expression was decreased markedly in liver of NAFLD patients, compared to controls. In addition, TM6SF2 immunoreactivity was reduced in subjects carrying at least one copy of the T allele, consistent with a difference in liver allele-specific transcript abundance. CONCLUSION: rs58542926 is a low-frequency variant with a modest effect on NAFLD, suggesting that carriers of the T allele are slightly more likely to accumulate fat in the liver and develop nonalcoholic steatohepatitis than those without. TM6SF2 appears to play a significant role in disease biology.
Assuntos
Fígado/patologia , Proteínas de Membrana/genética , Hepatopatia Gordurosa não Alcoólica/genética , Adulto , Idoso , Alelos , Doenças Cardiovasculares/genética , Estudos de Casos e Controles , Progressão da Doença , Feminino , Fibrose , Predisposição Genética para Doença , Variação Genética , Humanos , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/patologia , Polimorfismo de Nucleotídeo ÚnicoRESUMO
OBJECTIVES: We used a screening strategy of global serum microRNA (miRNA) profiling, followed by a second stage of independent replication and exploration of liver expression of selected miRNAs to study: (1) the circulating miRNA signature associated with non-alcoholic fatty liver disease (NAFLD) progression and predictive power, (2) the role of miRNAs in disease biology and (3) the association between circulating miRNAs and features of the metabolic syndrome. METHODS: The study used a case-control design and included patients with NAFLD proven through biopsy and healthy controls. RESULTS: Among 84 circulating miRNAs analysed, miR-122, miR-192, miR-19a and miR-19b, miR-125b, and miR-375 were upregulated >2-fold (p<0.05) either in simple steatosis (SS) or non-alcoholic steatohepatitis (NASH). The most dramatic and significant fold changes were observed in the serum levels of miR-122 (7.2-fold change in NASH vs controls and 3.1-fold change in NASH vs SS) and miR-192 (4.4-fold change in NASH vs controls); these results were replicated in the validation set. The majority of serum miR-122 circulate in argonaute2-free forms. Circulating miR-19a/b and miR-125b were correlated with biomarkers of atherosclerosis. Liver miR-122 expression was 10-fold (p<0.03) downregulated in NASH compared with SS and was preferentially expressed at the edge of lipid-laden hepatocytes. In vitro exploration showed that overexpression of miR-122 enhances alanine aminotransferase activity. CONCLUSIONS: miR-122 plays a role of physiological significance in the biology of NAFLD; circulating miRNAs mirror the histological and molecular events occurring in the liver. NAFLD has a distinguishing circulating miRNA profile associated with a global dysmetabolic disease state and cardiovascular risk.
Assuntos
Fígado/patologia , MicroRNAs/sangue , Hepatopatia Gordurosa não Alcoólica/genética , RNA não Traduzido/sangue , Adulto , Antropometria/métodos , Proteínas Argonautas/sangue , Proteínas Argonautas/genética , Biomarcadores/sangue , Biópsia , Estudos de Casos e Controles , Células Cultivadas , Simulação por Computador , Feminino , Perfilação da Expressão Gênica/métodos , Estudos de Associação Genética/métodos , Predisposição Genética para Doença , Humanos , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/patologia , Transaminases/metabolismo , Regulação para Cima/fisiologiaRESUMO
The intrahepatic cholestasis of pregnancy (ICP) is a multifactorial liver disorder which pathogenesis involves the interplay among abnormal bile acid (BA) levels, sex hormones, environmental factors, and genetic susceptibility. The dynamic nature of ICP that usually resolves soon after delivery suggests the possibility that its pathobiology is under epigenetic modulation. We explored the status of white blood peripheral cells-DNA methylation of CpG-enriched sites at the promoter of targeted genes (FXR/NR1H4, PXR/NR1I2, NR1I3, ESR1, and ABCC2) in a sample of 88 ICP patients and 173 healthy pregnant women in the third trimester of their pregnancies. CpG dinucleotides at the gene promoter of nuclear receptors subfamily 1 members and ABCC2 transporter were highly methylated during healthy pregnancy. We observed significant differences at the distal (-1890) and proximal promoter (-358) CpG sites of the FXR/NR1H4 and at the distal PXR/NR1I2 (-1224) promoter, which were consistently less methylated in ICP cases when compared with controls. In addition, we observed that methylation at FXR/NR1H4-1890 and PXR/NR1I2-1224 promoter sites was highly and positively correlated with BA profiling, particularly, conjugated BAs. Conversely, methylation level at the proximal FXR/NR1H4-358 CpG site was significantly and negatively correlated with the primary cholic and secondary deoxycholic acid. In vitro exploration showed that epiallopregnanolone sulfate, a reported FXR inhibitor, regulates the transcriptional activity of FXR/NR1H4 but seems to be not involved in the methylation changes. In conclusion, the identification of epigenetic marks in target genes provides a basis for the understanding of adverse liver-related pregnancy outcomes, including ICP.
Assuntos
Colestase Intra-Hepática/metabolismo , Metilação de DNA , Fenótipo , Complicações na Gravidez/metabolismo , Regiões Promotoras Genéticas , Receptores Citoplasmáticos e Nucleares/metabolismo , Adulto , Linhagem Celular Tumoral , Colestase Intra-Hepática/genética , Colestase Intra-Hepática/patologia , Receptor Constitutivo de Androstano , Epigênese Genética/efeitos dos fármacos , Epigênese Genética/genética , Feminino , Humanos , Masculino , Proteína 2 Associada à Farmacorresistência Múltipla , Gravidez , Complicações na Gravidez/genética , Complicações na Gravidez/patologia , Pregnanolona/análogos & derivados , Pregnanolona/farmacologia , Receptores Citoplasmáticos e Nucleares/genética , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/genéticaRESUMO
AIMS AND METHODS: We evaluated the modulation of liver stearoyl-CoA desaturase-1 (Scd1) by dietary factors and insulin resistance (IR) in two experimental models of high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD). The first model included Sprague Dawley (SD) rats that developed NAFLD without IR, and the second one included a rat model of genetic IR and cardiovascular disease, the spontaneously hypertensive rats (SHR) and its normotensive, insulin-sensitive control Wistar-Kyoto (WKY). The adult rats were given standard chow diet (CD) or HFD for 10 weeks. In all the animals, we explored the hepatic Scd1 transcriptional activity and protein levels. RESULTS: HFD-fed rats of both strains developed severe NAFLD. Liver abundance of Scd1 mRNA was significantly decreased in HFD-fed rats regardless of the strain; SD-CD: 235±195 vs. SD-HFD 4.5±2.9, p<0.0004, and SHR-CD: 75.6±10.8 vs. SHR-HFD: 4.48±17.4, and WKY-CD: 168.7±17.4 vs. WKY-HFD: 12.9±17.4, p<0.000001 (mean±SE, ANCOVA adjusted by HOMA). Analysis of liver Scd1 protein expression showed a particular pattern in the HFD groups, characterized by the presence of high levels of a monomeric protein band (32.2-36.6 Kda, p<0.003) and decreased levels of a dimeric protein band (61.9-66.1 Kda, p<0.02) regardless of the rat strain. Pharmacologic intervention with the peroxisome proliferator-activated receptor α agonist clofibrate reverted the liver phenotype and significantly modified the hepatic Scd1 transcriptional activity and protein expression. CONCLUSION: Diet-induced fatty liver is associated with the downregulation of hepatic Scd1 transcript and de-dimerization of the protein, and these changes were not much affected by the status of peripheral IR.
Assuntos
Fígado Gorduroso/enzimologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Resistência à Insulina/fisiologia , Estearoil-CoA Dessaturase/metabolismo , Análise de Variância , Animais , Western Blotting , Dieta Hiperlipídica/efeitos adversos , Dimerização , Ensaio de Imunoadsorção Enzimática , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Fígado/metabolismo , Masculino , Hepatopatia Gordurosa não Alcoólica , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estatísticas não ParamétricasRESUMO
UNLABELLED: Insulin resistance (IR) and mitochondrial dysfunction play a central role in the pathophysiology of nonalcoholic fatty liver disease (NAFLD). We hypothesized that genetic factors and epigenetic modifications occurring in the liver contribute to the IR phenotype. We specifically examined whether fatty liver and IR are modified by hepatic DNA methylation of the peroxisome proliferator-activated receptor γ coactivator 1α (PPARGC1A) and mitochondrial transcription factor A (TFAM) promoters, and also evaluated whether liver mitochondrial DNA (mtDNA) content is associated with NAFLD and IR. We studied liver biopsies obtained from NAFLD patients in a case-control design. After bisulfite treatment of DNA, we used methylation-specific polymerase chain reaction (PCR) to assess the putative methylation of three CpG in the PPARGC1A and TFAM promoters. Liver mtDNA quantification using nuclear DNA (nDNA) as a reference was evaluated by way of real-time PCR. Liver PPARGC1A methylated DNA/unmethylated DNA ratio correlated with plasma fasting insulin levels and homeostasis model assessment of insulin resistance (HOMA-IR); TFAM methylated DNA/unmethylated DNA ratio was inversely correlated with insulin levels. PPARGC1A promoter methylation was inversely correlated with the abundance of liver PPARGC1A messenger RNA. The liver mtDNA/nDNA ratio was significantly higher in control livers compared with NAFLD livers. mtDNA/nDNA ratio was inversely correlated with HOMA-IR, fasting glucose, and insulin and was inversely correlated with PPARGC1A promoter methylation. CONCLUSION: Our data suggest that the IR phenotype and the liver transcriptional activity of PPARGC1A show a tight interaction, probably through epigenetic modifications. Decreased liver mtDNA content concomitantly contributes to peripheral IR.
Assuntos
Epigênese Genética/fisiologia , Fígado Gorduroso/genética , Proteínas de Choque Térmico/genética , Resistência à Insulina/genética , PPAR gama/genética , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/genética , Adulto , Estudos de Casos e Controles , Ilhas de CpG/genética , Metilação de DNA , DNA Mitocondrial/metabolismo , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias Hepáticas/fisiologia , Proteínas Mitocondriais/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , RNA Mensageiro/metabolismoRESUMO
Presentamos la experiencia de la pesquisa de hipotiroidismo congénito (HC) en la que se evaluaron 37.750 neonatos nacidos en el Hospital Italiano de Buenos Aires y su filial de San Justo entre los años 1989 y 2007. Se midió tirotrofina por radioinmunoensayo. Se detectaron 25 neonatos con HC: 10 definitivos, 2 transitorios y 13 no confirmados aún; como resultado se registró una prevalencia de HC definitivo de 1/3 775. La causa más frecuente de HC definitivo fue la disgenesia tiroidea. El permanente ajuste de los valores de corte de TSH hizo posible disminuir el porcentaje de falsos positivos y consecuentemente el porcentaje de recitación en un 91.3% en este período. Enfatizamos la importancia de la detección temprana del HC a fin de instaurar un tratamiento precoz y evitar así el retardo mental y neurológico que esta enfermedad produce.
To assess the occurrence of congenital hypothyroidism (CH), 37 750 newborns were evaluated at Hospital Italiano deBuenos Aires and its affiliated hospital in San Justo between 1989 and 2007. Determination of thyrotropin by radioimmunoassay allowed for the detection of 25 newborns with CH of whom 10 were definitive, 2 transient and 13 without confirmation at the current time. The prevalence of definitive CH was 1/3775 newborns, being thyroid dysgenesis the most common cause of the disease. A continuous adjustment of TSH threshold values resulted in a decrease of false positive cases with a consequent reduction of 91.3% on office visits for follow-up during this period.We remark on the importance of an early detection of CH so that treatment can be initiated to prevent mental and neurological retardation associated with the disease.
Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Diagnóstico Precoce , Hipotireoidismo Congênito/diagnóstico , Hipotireoidismo/prevenção & controle , Receptores da Tireotropina , Disgenesia da Tireoide , Tireotropina/análiseRESUMO
Ectopic acromegaly represents less than 1% of the reported cases of acromegaly. Although clinical improvement is common after treatment with somatostatin (SMS) analogs, the biochemical response and tumor size of the growth hormone-releasing hormone (GHRH)-producing tumor and its metastases are less predictable. Subject A 36-year-old male was referred because of a 3-year history of acromegaly related symptoms. He had undergone lung surgery in 1987 for a "benign" carcinoid tumor. Endocrine evaluation confirmed acromegaly Plasma IGF-1: 984 ng/ml (63-380), GH: 49.8 ng/ml (<5). MRI showed a large mass in the left cerebellopontine angle and diffuse pituitary hyperplasia. Pulmonary, liver and bone metastases were shown by chest and abdominal CT scans. Ectopic GHRH secretion was suspected. Methods Measurement of circulating GHRH levels by fluorescence immunoassay levels and immunohistochemical study of the primary lung tumor and metastatic tissue with anti-GHRH and anti-somatostatin receptor type 2 (sst2A) antibodies. Results Basal plasma GHRH: 4654 pg/ml (<100). Pathological study of liver and bone biopsy material and lung tissue removed 19 years earlier was consistent with an atypical carcinoid producing GHRH and exhibiting sst2A receptor expression. Treatment with octreotide LAR 20-40 mg q. month resulted in normalization of plasma IGF-1 levels. Circulating GHRH levels decreased dramatically. The size of the left prepontine cistern mass, with SMS receptors shown by a radiolabeled pentetreotide scan, decreased by 80% after 18 months of therapy. Total regression of pituitary enlargement was also observed. No changes were observed in lung and liver metastases. After 24 months of therapy the patient is asymptomatic and living a full and active life.
Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias Brônquicas/metabolismo , Neoplasias Brônquicas/secundário , Tumor Carcinoide/metabolismo , Tumor Carcinoide/secundário , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Hormônios Ectópicos/metabolismo , Hormônio do Crescimento Humano/metabolismo , Octreotida/uso terapêutico , Acromegalia/etiologia , Adulto , Glicemia/metabolismo , Neoplasias Brônquicas/tratamento farmacológico , Tumor Carcinoide/tratamento farmacológico , Ângulo Cerebelopontino/patologia , Humanos , Fígado/patologia , Imageamento por Ressonância Magnética , Masculino , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Receptores de Somatostatina/metabolismo , Imagem Corporal TotalRESUMO
La neoplasia endócrina múltiple tipo 2 (NEM 2) es un síndrome autosómico dominante identificado en 500-1.000 familias hasta la fecha. Todas las variantes de NEM 2 muestran una penetrancia mayor al 90% para la manifestación del carcinoma medular de tiroides, mientras que la penetrancia es menor y variable para el feocromocitoma (50%) y tumoresparatiroideos (25%). El CMTF es una variante rara dentro del NEM 2 en la que cuatro o más miembros de una familiapresentan evidencia de carcinoma medular de tiroides sin manifestación asociada de feocromocitoma o hiperparatiroidismo primario. En los últimos años, el estudio genético del proto-oncogen RET en los casos índices para carcinoma medular y en sus posibles portadores se ha impuesto debido a que se ha demostrado que la tiroidectomía en los primeros 2 a 5 añosde edad puede prevenir o curar el CMT, inclusive antes de su expresión bioquímica en el NEM 2. La indicación detiroidectomía profiláctica es menos clara en CMTF. Con respecto a las mutaciones halladas en el proto-oncogen RET(10q11.2) el 80-90% afectan el codón 634, y con menor frecuencia los codones 918 (10-20%), 620 (6-8%), 618 (3-5%), 611 (2-3%) y 609 (0-1%). En este trabajo presentamos una familia portadora de una mutación heterocigota infrecuente en el proto-oncogen RET, Cys611Trp, (sólo un caso previo mencionado en la literatura internacional) que no fue detectadaen un estudio genético previo. Se plantean dos posibles conductas en los dos niños asintomáticos, portadores de lamutación. Tiroidectomía preventiva, o la conducta expectante hasta la expresión bioquímica. Basándonos en distintosconsensos internacionales, nos inclinaríamos por la primera conducta.
Multiple endocrine neoplasia type 2 (MEN 2) is an autosomal dominant syndrome identified to date in 500-1.000 kindreds. All variants of MEN 2 show a penetrance higher than 90% for medullary thyroid carcinoma (MTC), whilst the penetrance for pheochromocytoma (50%) and parathyroid tumors (25%) is lower and variable. Familial medullary thyroid carcinoma (FMTC) is a rare variant of MEN 2, in which four or more members of a family have MTC without pheochromocytoma or primary hyperpathyroidism. In recent years genetic testing for the proto-oncogene RET mutations in the index case ofMTC and in possible carriers has been used, because it has been demonstrated that prophylactic thyroidectomy before 2 5 years of age can prevent or cure MTC in MEN 2, even before its biochemical expression. Prophylactic thyroidectomy is not so clearly beneficial in FMTC. Mutations in the proto-oncogene RET (10q11.2) affect codon 634 in 80 90%, and less frequently, codons 918 (10-20%), 620 (6-8%), 618 (3-5%), 611 (2-3%) and 609 (0-1%). In this report we describe a family with an infrequent mutation in the proto-oncogene RET, Cys611Trp, (only one case reported in the bibliography). This mutation had not been detected in a previous genetic study, and we discuss herein the clinical management. Two approaches for the 2 asymptomatic young carriers: 1) prophylactic thyroidectomy as soon as the mutation is detected or 2 ) to wait for a positive stimulated calcitonin test and then perform a thyroidectomy. Studies from an international consortium lead us to believe that an early prophylactic thyroidectomy is the appropiate course of action.