RESUMO
RESUMEN El plomo (Pb) es un metal pesado cuyas características físico-químicas lo convierten en un contaminante ambiental persistente, bioacumulable y de alta toxicidad. La biorremediación surge como una alternativa con múltiples ventajas en comparación con los tratamientos convencionales para remover contaminantes como metales pesados de aguas residuales, basándose en las capacidades de tolerancia y mecanismos de resistencia de los microorganismos. Con el fin de conocer la tolerancia de Pseudomonas spp. al plomo presente en aguas contaminadas, se obtuvieron cuatro aislados nativos, procedentes de aguas residuales colectadas en el río del Valle de Aburrá (zona norte), los cuales se caracterizaron bioquímicamente. Se realizaron bioensayos de tolerancia en diferentes concentraciones de plomo por difusión en agar, como prueba tamiz, y determinación de la concentración mínima inhibitoria, determinando la viabilidad del microorganismo en cada exposición. No se presentó diferencia significativa para la tolerancia al plomo entre los aislados, identificados bioquímicamente como Pseudomonas aeruginosa, ni entre las diferentes concentraciones de plomo a las cuales fueron expuestos los aislados. A partir de estos resultados, se discute a cerca de los mecanismos reportados por diferentes autores, mediante los cuales Pseudomonas spp. puede actuar en presencia de Plomo. De esta manera, se concluye que los aislados de Pseudomonas spp. presentan mecanismos de tolerancia y/o resistencia hasta concentraciones de 2500 mg/L en presencia de nitrato de plomo, como potenciales agentes que pueden integrarse en procesos que impulsan nuevas tecnologías de biorremediación.
ABSTRACT Lead (Pb) is a heavy metal whose physicochemical characteristics make it a persistent environmental pollutant, bioaccumulable and highly toxic. Bioremediation emerges as an alternative with multiple advantages compared to conventional treatments to remove contaminants such as heavy metals from wastewater, based on the tolerance capacities and/or resistance mechanisms of microorganisms. In order to know the tolerance of Pseudomonas spp. to the lead present in contaminated waters, four native isolates were obtained, coming from wastewater collected in the north from Aburrá Valley River, which were characterized biochemically. Tolerance bioassay was carried out in different concentrations of lead by agar diffusion, as a screening test, and determination of the minimum inhibitory concentration, determining the viability of the microorganism in each exposure. There was no significant difference for lead tolerance between the isolates, identified biochemically as Pseudomonas aeruginosa, nor between the different concentrations of lead to which the isolates were exposed. From these results, we discuss about the mechanisms reported by different authors, by means of which Pseudomonas spp. can act in the presence of lead. In this way, it is concluded that the isolates of Pseudomonas spp. they present tolerance and/or resistance mechanisms up to 2500 mg/L in the presence of lead nitrate, as potential agents that can be integrated into processes that promote new bioremediation technologies.
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El envejecimiento poblacional implica un desafío para la salud pública por las patologías cuyos casos aumentan con la extensión de la vida. Se ha propuesto que ciertas actividades de la vida diaria (AVDs) avanzadas de tiempo libre poseen un efecto bené+co en la cognición de los adultos mayores. El objetivo de este trabajo fue relevar estudios empíricos presentando evidencia respecto a la relación entre dichas actividades y el funcionamiento cognitivo, para países iberoamericanos. Se incluyeron trabajos escritos en español, portugués e inglés, de enero de 2012 a mayo de 2017, involucrando a adultos de 60 y más años de edad no institucionalizados. Se hallaron 15 trabajos. Considerados en su conjunto, existiría evidencia de una relación entre las mencionadas actividades y el rendimiento cognitivo. Los trabajos de diseño prospectivo y los de intervención indicarían que la realización de dichas actividades avanzadas incide bene+ciosamente en el funcionamiento cognitivo.
Population aging implies a challenge to public health for the pathologies whose cases increase with the extension of life. It has been proposed that certain leisure advanced activities of daily living (ATLs) have a bene+cial effect on the cognition of the elderly. The objective of this work was to relieve empirical studies presenting evidence regarding the relationship between these activities and cognitive functioning, for Iberoamerican countries. Works written in Spanish, Portuguese and English were included from January 2012 to May 2017, involving non-institutionalized adults aged 60 and over. Fifteen papers were found. Considered as a whole, there would be evidence of a relationship between these activities and cognitive performance. Prospective design and interventional studies would indicate that such advanced activities has a bene+cial impact on cognitive functioning.
Assuntos
Humanos , Dinâmica Populacional , Atividades Cotidianas , Saúde Pública , AdultoRESUMO
Current knowledge on the genetic basis of nonalcoholic fatty liver disease (NAFLD) suggests that variants contributing not only to the disease predisposition but histological severity as well are located in genes that regulate lipid metabolism. We explored the role of rs641738 C/T located in TMC4 (transmembrane channel-like 4) exon 1 (p.Gly17Glu) and 500 bases- downstream of MBOAT7 gene (TMC4/MBOAT7), in the genetic risk for developing NAFLD in a case-control study. Our sample included 634 individuals (372 patients with NAFLD diagnosed by liver biopsy and 262 control subjects); genotyping was performed by a Taqman assay. Genotype frequencies in controls (CC: 84, CT: 137, TT: 41) and patients (CC: 134, CT: 178, TT: 60) were in Hardy-Weinberg equilibrium; minor allele frequency 40.8%. Our sample had 84-99% power if an additive genetic model is assumed for estimated odds ratios of 1.3-1.5, respectively. We found no evidence of association between rs641738 and either NAFLD (Cochran-Armitage test for trend, p = 0.529) or the disease severity (p = 0.61). Low levels of MBOAT7 protein expression were found in the liver of patients with NAFLD, which were unrelated to the rs641738 genotypes. In conclusion, the role of rs641738 in the pathogenesis of NAFLD is inconclusive.
Assuntos
Aciltransferases/genética , Proteínas de Membrana/genética , Mutação de Sentido Incorreto , Hepatopatia Gordurosa não Alcoólica/genética , Polimorfismo de Nucleotídeo Único , Adulto , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
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.
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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
BACKGROUND AND AIMS: Nonalcoholic fatty liver disease (NAFLD) develops from a complex process, which includes changes in the liver methylome. Betaine plays a pivotal role in the regulation of methylogenesis. We performed a two-stage case-control study, which included patients with biopsy-proven NAFLD to explore circulating levels of betaine and its association with the histological spectrum. We also explored the association between a missense rs1805074, p.Ser646Pro variant in DMGDH (dimethylglycine dehydrogenase mitochondrial) and NAFLD severity (n=390). RESULTS: In the discovery phase (n=48), betaine levels were associated with the disease severity (P=.0030), including liver inflammation (Spearman R:-0.51, P=.001), ballooning degeneration (R: -0.50, P=.01) and fibrosis (R: -0.54, P=.0008). Betaine levels were significantly decreased in nonalcoholic steatohepatitis (NASH) in comparison with nonalcoholic fatty liver (NAFL). Further replication (n=51) showed that betaine levels were associated with advanced NAFLD (P=.0085), and patients with NASH had a 1.26-fold decrease in betaine levels compared with those with NAFL. The rs1805074 was significantly associated with the disease severity (P=.011). CONCLUSION: NAFLD severity is associated with a state of betaine-insufficiency.
Assuntos
Betaína/sangue , Dimetilglicina Desidrogenase/genética , Progressão da Doença , Proteínas Mitocondriais/genética , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/genética , Adulto , Argentina , Biomarcadores , Estudos de Casos e Controles , Fígado Gorduroso/patologia , Feminino , Fibrose , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Hepatopatia Gordurosa não Alcoólica/patologia , Análise de Regressão , Índice de Gravidade de DoençaRESUMO
Non-alcoholic fatty liver disease (NAFLD) is associated with mitochondrial dysfunction, a decreased liver mitochondrial DNA (mtDNA) content, and impaired energy metabolism. To understand the clinical implications of mtDNA diversity in the biology of NAFLD, we applied deep-coverage whole sequencing of the liver mitochondrial genomes. We used a multistage study design, including a discovery phase, a phenotype-oriented study to assess the mutational burden in patients with steatohepatitis at different stages of liver fibrosis, and a replication study to validate findings in loci of interest. We also assessed the potential protein-level impact of the observed mutations. To determine whether the observed changes are tissue-specific, we compared the liver and the corresponding peripheral blood entire mitochondrial genomes. The nuclear genes POLG and POLG2 (mitochondrial DNA polymerase-γ) were also sequenced. We observed that the liver mtDNA of patients with NAFLD harbours complex genomes with a significantly higher mutational (1.28-fold) rate and degree of heteroplasmy than in controls. The analysis of liver mitochondrial genomes of patients with different degrees of fibrosis revealed that the disease severity is associated with an overall 1.4-fold increase in mutation rate, including mutations in genes of the oxidative phosphorylation (OXPHOS) chain. Significant differences in gene and protein expression patterns were observed in association with the cumulative number of OXPHOS polymorphic sites. We observed a high degree of homology (â¼98%) between the blood and liver mitochondrial genomes. A missense POLG p.Gln1236His variant was associated with liver mtDNA copy number. In conclusion, we have demonstrated that OXPHOS genes contain the highest number of hotspot positions associated with a more severe phenotype. The variability of the mitochondrial genomes probably originates from a common germline source; hence, it may explain a fraction of the 'missing heritability' of NAFLD. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Assuntos
Genoma Mitocondrial , Hepatopatia Gordurosa não Alcoólica/genética , Adulto , Estudos de Casos e Controles , DNA Mitocondrial/genética , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Haplótipos , Humanos , Cirrose Hepática/genética , Masculino , Pessoa de Meia-Idade , Mitocôndrias Hepáticas/genética , Mutação , Mutação de Sentido Incorreto/genética , Fosforilação Oxidativa , Polimorfismo Genético , Índice de Gravidade de DoençaRESUMO
Ballooning degeneration (BD) of hepatocytes is a distinguishing histological feature associated with the progression of nonalcoholic fatty liver disease (NAFLD). Under the assumption that NAFLD severity is associated with metabolic-stress we explored the hypothesis that heat shock 27 kDa protein 1 (HSP27), a protein chaperone involved in stress resistance and cytoskeletal-remodeling, might be deregulated in ballooned hepatocytes. We observed that fasting plasma glucose (fpG) (p = 0.00002), total cholesterol (p = 0.02) and triglycerides (p = 0.01) levels, and female sex (p = 0.01) were significantly associated with the presence of BD. A logistic regression model showed that BD was independently associated with fpG (p = 0.002); OR per unit of glucose concentration 1.05, 95% confidence interval 1.02-1.09. Furthermore, BD was associated with a significant 2.24-fold decrease in the expression level of HSP27-mRNA in comparison with absence of ballooning, p = 0.002. Ballooned hepatocytes showed very low HSP27 immunoreactivity compared with hepatocyes without ballooning (p = 0.009); HSP27 immunoreactivity was inversely correlated with fpG levels (R: -0.49, p = 0.01). In conclusion, BD is associated with down-regulation of liver HSP27 gene and protein expression, suggesting that ballooned hepatocytes fail to ensure a robust physiological response to metabolic-induced stress.
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Regulação para Baixo , Proteínas de Choque Térmico HSP27/biossíntese , Hepatócitos/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Adulto , Feminino , Proteínas de Choque Térmico , Hepatócitos/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Chaperonas Moleculares , Hepatopatia Gordurosa não Alcoólica/patologia , Hepatopatia Gordurosa não Alcoólica/terapiaRESUMO
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.
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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/fisiologiaAssuntos
Fígado Gorduroso/etiologia , Lipase/genética , Proteínas de Membrana/genética , Animais , Feminino , Humanos , MasculinoRESUMO
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
OBJECTIVE & DESIGN: Nonalcoholic fatty liver disease (NAFLD) is a clinical condition that refers to progressive histological changes ranging from simple steatosis (SS) to nonalcoholic steatohepatitis (NASH). We evaluated the status of cytosine methylation (5mC) of liver mitochondrial DNA (mtDNA) in selected regions of the mtDNA genome, such as D-loop control region, and mitochondrially encoded NADH dehydrogenase 6 (MT-ND6) and cytochrome C oxidase I (MT-CO1), to contrast the hypothesis that epigenetic modifications play a role in the phenotypic switching from SS to NASH. METHODS: We studied liver biopsies obtained from patients with NAFLD in a case-control design; 45 patients and 18 near-normal liver-histology subjects. RESULTS: MT-ND6 methylation was higher in the liver of NASH than SS patients (p < 0.04) and MT-ND6 methylated DNA/unmethylated DNA ratio was significantly associated with NAFLD activity score (p < 0.02). Liver MT-ND6 mRNA expression was significantly decreased in NASH patients (0.26 ± 0.30) versus SS (0.74 ± 0.48), p < 0.003, and the protein level was also diminished. The status of liver MT-ND6 methylation in NASH group was inversely correlated with the level of regular physical activity (R = -0.54, p < 0.02). Hepatic methylation levels of D-Loop and MT-CO1 were not associated with the disease severity. DNA (cytosine-5) methyltransferase 1 was significantly upregulated in NASH patients (p < 0.002). Ultrastructural evaluation showed that NASH is associated with mitochondrial defects and peroxisome proliferation. CONCLUSION: Hepatic methylation and transcriptional activity of the MT-ND6 are associated with the histological severity of NAFLD. Epigenetic changes of mtDNA are potentially reversible by interventional programs, as physical activity could modulate the methylation status of MT-ND6.
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DNA (Citosina-5-)-Metiltransferases/genética , Fígado Gorduroso , Mitocôndrias Hepáticas , NADH Desidrogenase/genética , Adulto , Biópsia , Estudos de Casos e Controles , Citosina/metabolismo , DNA (Citosina-5-)-Metiltransferase 1 , Metilação de DNA/genética , DNA Mitocondrial , Progressão da Doença , Epigênese Genética , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Fígado Gorduroso/fisiopatologia , Feminino , Interação Gene-Ambiente , Humanos , Fígado/metabolismo , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Mitocôndrias Hepáticas/genética , Mitocôndrias Hepáticas/metabolismo , Hepatopatia Gordurosa não Alcoólica , Índice de Gravidade de Doença , Ativação Transcricional/genéticaRESUMO
OBJECTIVES AND DESIGN: Epidemiological studies have suggested a role of nonalcoholic fatty liver disease (NAFLD) in the development of cardiovascular disease. We evaluated liver mRNA expression of 84 genes encoding proteins involved in the atherosclerosis pathway in patients with NAFLD proven through biopsy in a case-control design, and examined the putative role of the histological disease severity in the molecular events associated with the atherogenic profile. RESULTS: Nonalcoholic steatohepatitis (NASH), when compared with simple steatosis (SS), significantly increases the expression of TGFB1 (6.8, p<0.005), angiotensin I-converting enzyme (ACE) (2.1, p<0.007), LAMA1 (2.1, p<0.007), SERPINB2 (2.1, p<0.007), CSF2 (2.5, p<0.002), IL1A (2.5, p<0.005), IL3 (2.1, p<0.007), IL4 (2.1, p<0.007), LIF (2.1, p<0.007), and MMP1 (2.1, p<0.007), and decreases the transcript levels of genes involved in the negative regulation of cell-death pathways. A post hoc analysis of liver biopsies of NASH patients who were treated with enalapril monotherapy because of arterial hypertension showed a significant association with lower fibrosis scores in comparison with untreated patients. BIRC3, a severe hypoxia-activated gene, was significantly increased in SS (8.2, p<0.004), when compared with the controls. NASH, but not SS, was also associated with a significant increase in platelet abundance of TGFB1 mRNA. Systems biology analysis revealed highly scored pathways involved in the regulation of programmed cell death, angiogenesis, and immune system, in which TGFB1 was mostly involved. CONCLUSION: NASH, but not SS, may increase atherosclerotic and cardiovascular risk by local overexpression of mediators of atherogenesis, endothelial damage, and regulators of blood pressure; this observation may have therapeutic implications, because ACE inhibitors may improve both cardiovascular outcomes and liver fibrosis. Hepatocyte hypoxia seems to have an important role in the molecular events activated by liver steatosis.
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Aterosclerose/patologia , Fígado Gorduroso/metabolismo , Fígado/metabolismo , Adulto , Biópsia , Pressão Sanguínea , Doenças Cardiovasculares/metabolismo , Estudos de Casos e Controles , Feminino , Fibrose , Regulação da Expressão Gênica , Hepatócitos/citologia , Humanos , Hipóxia/patologia , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica , RNA Mensageiro/metabolismo , Transcrição Gênica , Fator de Crescimento Transformador beta1/genéticaRESUMO
The regulation of mitochondrial DNA (mtDNA) copy number not only is critical for the maintenance of the normal mitochondrial function but has a strong clinical significance. A recent report revealed that the signal transducer and activator of transcription 3 (STAT3) is involved in the regulation of the mitochondrial function and is required for the optimal function of the electron transport chain. In this study, we explored whether gene variants in the STAT3 influence the leukocyte mtDNA copy number. Clinical data and blood samples were collected from 179 subjects (aged 52.8 ± 0.9 years). Mitochondrial DNA quantification using nuclear DNA (nDNA) as a reference was carried out by a real-time quantitative polymerase chain reaction method; results are presented as the mtDNA/nDNA ratio. We selected 3 tag single nucleotide polymorphisms showing a minor allele frequency greater than 10% (rs2293152 C/G, rs6503695 C/T, and rs9891119 A/C), representing 24 polymorphic sites of the STAT3 (r(2) > 0.8). We observed a significant association between mtDNA/nDNA ratio and both rs6503695 and rs9891119, adjusted by age and homeostasis model assessment index. The proportion of the total variance of the mtDNA/nDNA ratio accounted for by the rs6503695 and rs9891119 genotypes was 4.7% and 6.53%, respectively. Common variation in the STAT3 may influence mtDNA copy number.
Assuntos
DNA Mitocondrial/genética , Variação Genética , Fator de Transcrição STAT3/genética , Alelos , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/genética , Polimorfismo de Nucleotídeo ÚnicoRESUMO
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
OBJECTIVES: We evaluated circulating levels of biomarkers of atherosclerosis (soluble intercellular adhesion molecule: sICAM-1, plasminogen activator inhibitor: PAI-1 and soluble CD40 ligand: sCD40L) in patients with NAFLD proven through biopsy and control subjects, and correlated them with the histological disease severity. We further explored liver protein expression of ICAM-1, CD40 and PAI-1 in patients with different histological forms of NAFLD and control liver biopsies. PATIENTS AND METHODS: We included 215 individuals: 113 patients with NAFLD (simple steatosis n=45 and NASH n=68) and 102 control subjects. Circulating levels of the biomarkers were measured by ELISA. Liver expression of ICAM-1, CD40 and PAI-1 was assessed by immunohistochemistry using monoclonal antihuman antibodies. RESULTS: Patients with NAFLD, in comparison with control subjects, showed significantly higher circulating levels of sICAM-1 (605.3+/-34.6ng/ml vs. 356.5+/-24.6ng/ml, p=5.9 x 10(-6)), PAI-1 (22.8+/-1.7ng/ml vs. 19.0+/-2.1ng/ml, p=0.0149) and sCD40L (1347.5+/-513.7pg/ml vs. 804.5+/-396.1pg/ml, p=0.0229), results expressed as mean+/-SE. sICAM-1 was a strong predictor of histological severity of NAFLD, after adjusting for potential confounders. In addition, patients with NAFLD showed significantly higher liver staining scores for ICAM-1 and PAI-1 than control liver biopsies. ICAM-1 immunoreactivity in lobular inflammatory infiltrate showed high scores in NASH patients; a significant correlation was found between both the degree of liver steatosis and the severity of necroinflammatory activity and liver ICAM-1 expression. CONCLUSIONS: Our study shows that NAFLD is associated with elevated circulating levels and abnormal liver expression of molecular mediators of atherosclerosis. Additionally, ICAM-1 may be involved in liver damage and inflammation.
Assuntos
Biomarcadores/sangue , Ligante de CD40/sangue , Fígado Gorduroso/sangue , Molécula 1 de Adesão Intercelular/sangue , Fígado/metabolismo , Inibidor 1 de Ativador de Plasminogênio/sangue , Adulto , Aterosclerose/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: To explore the contribution of gene variants and derived haplotypes of the pregnane X receptor (NR1I2) to the severity of nonalcoholic fatty liver disease (NAFLD). METHODS: A total of 290 individuals were evaluated in a case-control association study, including 188 NAFLD patients with different stages of disease severity and 102 healthy individuals. Four tag single nucleotide polymorphisms (SNPs; rs12488820 C/T, rs2472671 C/T, rs2461823 A/G, and rs1054191 A/G) encompassing 36 kb in chromosome 3 and representing 33 polymorphic sites (r2>0.8) were genotyped. Four additional SNPs (rs3814055, rs3814057, rs6785049, and rs7643645) were also included because they showed earlier evidence of functionality. RESULTS: Genotypic tests for single SNPs showed that rs7643645 and rs2461823 were significantly associated with disease severity by ordinal multinomial analysis (P<0.0015 and 0.039, respectively). A significant association was also observed under the additive model for both variants (P<0.00038 and 0.012, respectively). Consistent with the analysis of individual markers, we observed that the multimarker composed of rs2461823/A-rs7643645/G was significantly associated with disease severity (P<6.9 x 10(-5), beta: 0.45). In addition, the rs7643645/G variant was significantly associated with ALT level (P<0.026), a surrogate marker of severe liver injury. Finally, in univariate analysis rs7643645/G was significantly associated with fatty liver disease (P<0.04), with an odds ratio of 1.457 (95% confidence interval: 1.018-2.086). CONCLUSION: Our study suggests that pregnane X receptor polymorphisms and related haplotypes may contribute to disease severity in NAFLD by influencing the individual susceptibility to progress to more severe stages of the disease.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/genética , Polimorfismo de Nucleotídeo Único/genética , Receptores de Esteroides/genética , Estudos de Casos e Controles , Doença Hepática Induzida por Substâncias e Drogas/patologia , Estudos Transversais , Fígado Gorduroso/genética , Fígado Gorduroso/patologia , Feminino , Estudos de Associação Genética , Genótipo , Haplótipos/genética , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Receptor de Pregnano XRESUMO
We explored the role of the adiponutrin (PNPLA3) nonsynonymous-rs738409 single nucleotide polymorphism (SNP) in genetic susceptibility to nonalcoholic fatty liver disease (NAFLD) and whether this SNP contributes to the severity of histological disease. Two hundred sixty-six individuals were evaluated in a case-control association study, which included 172 patients with features of NAFLD and 94 control subjects. The rs738409 G allele was significantly associated with NAFLD (P < 0.001; OR 2.8 95%, CI 1.5-5.2), independent of age, sex, body mass index (BMI), and Homeostasis Model Assessment (HOMA) index. When we tested the hypothesis of a relation between the SNP and the histological spectrum of NAFLD, a significant association was observed [chi2 19.9, degree of freedom (df): 2, P < 5 x 10(-5), adjusted for HOMA and BMI]. The degree of liver steatosis, as evaluated by liver biopsy, was significantly associated with the rs738409 G allele. Patients with CC genotype showed a lower steatosis score (14.9% +/- 3.9) in comparison with the CG genotype (26.3% +/- 3.5) and GG genotype (33.3% +/- 4.0) (P < 0.005). The proportion of the total variation attributed to rs738409 genotypes was 5.3% (beta 0.23 +/- 0.07; P < 0.002). Our data suggest that the rs738409 G allele is associated not only with fat accumulation in the liver but also with liver injury, possibly triggered by lipotoxicity.
Assuntos
Fígado Gorduroso/genética , Proteínas de Membrana/genética , Adulto , Estudos Transversais , Feminino , Predisposição Genética para Doença/genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
BACKGROUND: The diagnosis and treatment of intrahepatic cholestasis of pregnancy (ICP) has important implications on fetal health. The biochemical parameter commonly used in the diagnosis of ICP is the determination of the concentration of total serum bile acids (TSBA). However, bile acid profile, especially lithocholic acid (LCA) analysis is a more sensitive and specific biomarker for differential diagnosis of this pathology and also could be an alternative to evaluate the efficiency of ursodeoxycholic acid (UDCA) for ICP treatment. METHODS: Serum bile acid (SBA) profiles including LCA determination, were studied in 28 ICP patients using a capillary electrophoresis method. The effects of UDCA treatment on bile acid profile, were analysed in 23 out of 28 ICP patients and the two samples obtained before and 15 days after treatment were compared. Two samples taken as controls were also obtained from each of five patients without therapy. RESULTS: A dramatic decrease in LCA concentrations and maintenance of TSBA concentrations were found in all patients after UDCA therapy, whereas SBA profiles together with LCA values did not change in patients without therapy. CONCLUSION: We propose LCA as an alternative biomarker and a more sensitive parameter than TSBA to evaluate the effectiveness of UDCA treatment, at least in ICP patients from Argentina.