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1.
Rev Esp Enferm Dig ; 110(3): 204-206, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29277999

RESUMO

Hepatic adenomatosis is a benign disease defined as the presence of multiple adenomas in a normal liver. It is an uncommon condition and there are less than a hundred reported cases in the literature. The etiology is unknown, although it has been associated with the use of oral contraceptives, anabolic steroids, certain storage diseases and some genetic mutations linked to maturity onset diabetes of the young. The coexistence of hepatic adenomatosis and nonalcoholic steatohepatitis has been recently described in two patients suffering from metabolic syndrome. This association is particularly interesting due to the growing prevalence of nonalcoholic fatty liver disease in developed countries and the possibility of a common causal pathway. We report the case of a young woman with fructosemia and hepatic steatosis; multiple hepatic adenomas associated to steatohepatitis lesions were also found during clinical follow-up. The possible implications are discussed.


Assuntos
Adenoma/complicações , Neoplasias Hepáticas/complicações , Hepatopatia Gordurosa não Alcoólica/complicações , Adenoma/diagnóstico por imagem , Adenoma/patologia , Adulto , Feminino , Intolerância à Frutose/etiologia , Fator 1 Nuclear de Hepatócito , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Imagem por Ressonância Magnética , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Hepatopatia Gordurosa não Alcoólica/patologia
2.
Biochem Biophys Res Commun ; 495(2): 1758-1765, 2018 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-29233692

RESUMO

The chipmunk hibernation-related proteins (HPs) HP-20 and HP-27 are components of a 140-kDa complex that dramatically decreases in the blood during hibernation. The HP-20 and HP-27 genes are expressed specifically in the liver and are downregulated in hibernating chipmunks. Hibernation-associated physiological changes are assumed to be under genetic control. Therefore, to elucidate the molecular mechanisms of hibernation, here we examined the mechanisms behind the altered HP-20 and HP-27 gene expression in nonhibernating versus hibernating chipmunks. Chromatin immunoprecipitation (ChIP) analyses revealed that histone H3 on the HP-20 and HP-27 gene promoters was highly acetylated at lysine (K) 9 and K14 and highly trimethylated at K4 in the liver of nonhibernating chipmunks, while these active histone modifications were nearly absent in hibernating chipmunks. Furthermore, histone acetyltransferases and a histone methyltransferase were associated with the HP-20 and HP-27 gene promoters primarily in nonhibernating chipmunks. Consistent with a previous finding that HNF-1 and USF can activate HP-20 and HP-27 gene transcription by binding to the proximal promoter region, ChIP-quantitative PCR (qPCR) analyses revealed that significantly less HNF-1 and USF were bound to these gene promoters in hibernating than in nonhibernating chipmunks. These findings collectively indicated that the hibernation-associated HP-20 and HP-27 gene expression is epigenetically regulated at the transcriptional level by the binding of HNF-1 and USF to their proximal promoters, and that histone modification has a key role in hibernation-associated transcriptional regulation.


Assuntos
Proteínas Sanguíneas/genética , Proteínas Sanguíneas/fisiologia , Hibernação/genética , Hibernação/fisiologia , Sciuridae/genética , Sciuridae/fisiologia , Animais , Sequência de Bases , Epigênese Genética , Expressão Gênica , Fator 1 Nuclear de Hepatócito/metabolismo , Histonas/metabolismo , Masculino , Regiões Promotoras Genéticas , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Genética , Fatores Estimuladores Upstream/metabolismo
3.
Zhonghua Er Ke Za Zhi ; 55(9): 658-662, 2017 Sep 02.
Artigo em Chinês | MEDLINE | ID: mdl-28881510

RESUMO

Objective: Hepatocyte nuclear factor 1 homeobox b (HNF1B) -associated disease is an autosomal dominant inherited disorder with a variable, multi-systemic phenotype. In China, five adult probands and one child proband with HNF1B-associated disease had been reported, whereas few fetuses are described. The aims of this retrospective study were to understand about the clinical manifestations of HNF1B-associated disease and to further improve the recognition of this disorder. Method: Four patients (3 males, 1 female) and three fetuses with HNF1B mutations were included in this study. They were admitted to our hospital from January 2013 to March 2017. HNF1B mutations were detected using targeted next generation sequencing and quantitative real-time PCR or Sanger sequencing. HNF1B heterozygous deletion of exons 1-9 was found in 4 patients and 2 fetuses, and HNF1B heterozygous missense mutation in 1 fetus. These two mutations had been reported. Two patients and 1 fetus had de novo mutations. Results of renal ultrasonography with or without magnetic resonance imaging, biochemical investigations, urine routine examination and other necessary investigations in 7 cases were analyzed. Result: Three patients were Han Chinese ethnicity, and one patient was Mongolian. In patients 1 and 4, abnormal fetal kidneys were discovered by routine ultrasonography, and the age at first feature identified in Patients 2 and 3 were 13 years and 28 years. Patient 3 had normal renal function and the remainder had reduced glomerular filtration rate. In addition, patient 4 presented with nephrotic syndrome and glycosuria, patient 2 with early onset hyperparathyroidism and renal osteodystrophy, and patient 3 with diabetes mellitus. All the 4 patients had renal structural abnormalities including bilateral multiple renal cysts, dysplasia and hyperechogenic kidneys. Only patient 3 had a positive family history of renal diseases, the remainder had a negative family history of renal diseases. In 3 fetuses, prenatal ultrasound anomalies were detected during the second trimester. These 3 fetuses had hyperechogenic kidneys with or without renal cysts. Polyhydramnios was detected in only one of the 3 fetuses. Two of the 3 fetuses had a positive family history of renal diseases. Conclusion: Clinical phenotypes of HNF1B-related disease are heterogeneous, renal malformations clearly appear to be the most common manifestation, multiple renal cysts are characteristic, and patients can progress to impaired kidney function during childhood; HNF1B mutation is a differential diagnosis of fetal hyperechogenic kidneys or multiple renal cysts.


Assuntos
Fator 1-beta Nuclear de Hepatócito , Nefropatias/genética , Mutação , Fenótipo , Adulto , Criança , China , Feminino , Genes Homeobox , Fator 1 Nuclear de Hepatócito/genética , Fator 1-beta Nuclear de Hepatócito/genética , Humanos , Masculino , Gravidez , Estudos Retrospectivos
4.
Int J Mol Med ; 39(3): 749-756, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28204827

RESUMO

Proprotein convertase subtilisin/kexin type 9 (PCSK9) impedes low­density lipoprotein (LDL) receptor (LDLR)-mediated LDL-cholesterol uptake and has hence emerged as a critical regulator of serum cholesterol levels and a new therapeutic target for the treatment of hypercholesterolemia. Statins have been shown to elevate circulating PCSK9 levels by stimulating PCSK9 gene transcription, which reduces the clinical efficacy of statin in LDL­cholesterol reduction. The transcription of PCSK9 is partially controlled by the hepatocyte nuclear factor 1 (HNF1) binding site embedded in the proximal region of its promoter. In this study, we utilized adenoviral shRNA delivery vectors to generate liver-specific knockdown of HNF1α (Ad­shHNF1α) or HNF1ß (Ad­shHNF1ß) in hamsters to examine the impact of reduced hepatic expression of HNF1 transcription factors on statin­induced elevation of PCSK9 expression and serum cholesterol levels. We showed that the administration of rosuvastatin (RSV) to normolipidemic hamsters significantly augmented hepatic PCSK9 expression and serum PCSK9 levels. In addition, RSV treatment increased hepatic HNF1α protein levels without a clear effect on HNF1α mRNA expression. Injection of Ad-shHNF1α or Ad­shHNF1ß into hamsters both blunted RSV­induced elevation of PCSK9 serum concentration and hepatic mRNA and protein levels, which led to significant increases in liver LDLR protein abundance. Furthermore, hepatic depletion of HNF1 factors lowered circulating total cholesterol and non­high density lipoprotein cholesterol levels in RSV­treated hamsters. Our study demonstrates that both HNF1α and HNF1ß are positive regulators of hepatic PCSK9 transcription in hamster species and that transient, liver-specific knockdown of either HNF1α or HNF1ß could antagonize the RSV­induced elevation of serum PCSK9 and reduce circulating cholesterol levels.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Fator 1 Nuclear de Hepatócito/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Pró-Proteína Convertase 9/genética , Rosuvastatina Cálcica/farmacologia , Adenoviridae/genética , Animais , Sequência de Bases , Colesterol/sangue , Clonagem Molecular , Cricetinae , Técnicas de Silenciamento de Genes , Inativação Gênica , Vetores Genéticos/genética , Fator 1 Nuclear de Hepatócito/genética , Fator 1-alfa Nuclear de Hepatócito/genética , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Fator 1-beta Nuclear de Hepatócito/genética , Fator 1-beta Nuclear de Hepatócito/metabolismo , Fígado/metabolismo , Masculino , Pró-Proteína Convertase 9/sangue , Pró-Proteína Convertase 9/metabolismo , RNA Interferente Pequeno/genética , Receptores de LDL/metabolismo , Transdução de Sinais , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , Transdução Genética
5.
Minerva Endocrinol ; 42(1): 30-40, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26337491

RESUMO

BACKGROUND: Recent studies suggest that stem cells may represent a putative source for the generation of beta cells. However, the identity and characteristics of stem cells from adult pancreas and conditions for their large scale expansion are still poorly defined. METHODS: DPC were isolated from adult pancreatic ducts of C57Bl/6 mice. Expression profile was investigated by PCR, FACS and immunohistochemistry. RESULTS: DPC express a panel of stem cell associated markers such as Pdx-1, cytokeratin-19 (CK19), nestin, Sox9 together with the transcription factor MafA and hepatic nuclear factors HNF1ß, HNF3ß, HNF4α und HNF6. This gene expression profile is suggesting that DPC might be a promising tool for endocrine differentiation. After stimulation with picolinic acid and hypoxia, DPC expressed the endocrine differentiation marker Ngn3. Nevertheless, insulin production was not observed. CONCLUSIONS: We here describe a protocol for the isolation end expansion of murine pancreatic ductal progenitor cells (DPC) displaying high self-renewal, spheroid- and colony-forming capacity. Further studies are required to elucidate the conditions for differentiation into mature pancreatic endocrine cell lineages.


Assuntos
Fator 1 Nuclear de Hepatócito/genética , Proteínas de Homeodomínio/genética , Queratinas/metabolismo , Fatores de Transcrição Maf Maior/genética , Nestina/genética , Ductos Pancreáticos/citologia , Ductos Pancreáticos/metabolismo , Fatores de Transcrição SOX9/genética , Células-Tronco/metabolismo , Transativadores/genética , Animais , Linhagem Celular , Linhagem da Célula , Camundongos , Camundongos Endogâmicos BALB C
6.
Br Poult Sci ; 58(1): 19-25, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27844479

RESUMO

1. Albumin (ALB) is a serum protein most highly expressed in liver and regarded as an effective indicator for liver pathologies. The objectives of this study were to determine the expression of duck ALB gene (duALB) in various non-hepatic tissues and identify the potential cis-regulatory elements in the promoter. 2. A model was established to assess duALB promoter activity in different cell lines by construction of a duALB promoter-driven GFP (Green Fluorescent Protein)-expressing vector, which exhibited high expression activity in liver-derived cells and lower expression in other cells. Through the firefly luciferase reporter gene driven by a series of constructs carrying progressive deletions, the core transcriptional regulatory region within the duALB promoter was identified. Mutations in candidate-binding sites were made by site-directed mutagenesis. 3. The core transcriptional regulatory region was located in the -190/-51 bp region. This region contains three potential transcription factor-binding sites, one each for hepatocyte nuclear factor (HNF-3ß) (-158/-149), CCAAT/Enhancer-binding protein element (C/EBPα) (-119/-107) and nuclear factor-1 (HNF-1) (-67/-57). Site-directed mutagenesis of HNF-1 and C/EBPα-binding sites resulted in a significant reduction in duALB promoter activity. Two potential cis-regulatory elements (C/EBPα and HNF-1) were responsible for its transcriptional activity in liver-derived cells. 4. These findings contribute to the further understanding of the fundamental mechanisms of ALB gene regulation and the use of tissue-specific gene promoters to regulate tissue-specific expression of exogenous genes in vivo.


Assuntos
Patos/genética , Expressão Gênica/genética , Regiões Promotoras Genéticas/genética , Albumina Sérica/genética , Animais , Sítios de Ligação/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , DNA/metabolismo , Regulação da Expressão Gênica/genética , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Fator 1 Nuclear de Hepatócito/metabolismo , Fator 3-beta Nuclear de Hepatócito/metabolismo , Fígado/metabolismo , Mutagênese Sítio-Dirigida
7.
Mol Cell Endocrinol ; 425: 94-102, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26808453

RESUMO

The luminal environment of the epididymis participates in sperm maturation and impacts male fertility. It is dependent on the coordinated expression of many genes encoding proteins with a role in epithelial transport. We identified cis-regulatory elements for critical genes in epididymis function, by mapping open chromatin genome-wide in human epididymis epithelial (HEE) cells. Bioinformatic predictions of transcription factors binding to the regulatory elements suggested an important role for hepatocyte nuclear factor 1 (HNF1) in the transcriptional program of these cells. Chromatin immunoprecipitation and deep sequencing (ChIP-seq) revealed HNF1 target genes in HEE cells. In parallel, the contribution of HNF1 to the transcriptome of HEE cells was determined by RNA-seq, following siRNA-mediated depletion of both HNF1α and HNF1ß transcription factors. Repression of these factors caused differential expression of 1892 transcripts (902 were downregulated and 990 upregulated) in comparison to non-targeting siRNAs. Differentially expressed genes with HNF1 ChIP-seq peaks within 20 kb were subject to gene ontology process enrichment analysis. Among the most significant processes associated with down-regulated genes were epithelial transport of water, phosphate and bicarbonate, all critical processes in epididymis epithelial function. Measurements of intracellular pH (pHi) confirmed a role for HNF1 in regulating the epididymis luminal environment.


Assuntos
Epididimo/metabolismo , Redes Reguladoras de Genes , Fator 1 Nuclear de Hepatócito/genética , Fator 1 Nuclear de Hepatócito/metabolismo , Elementos Reguladores de Transcrição , Células Cultivadas , Imunoprecipitação da Cromatina , Biologia Computacional/métodos , Epididimo/citologia , Regulação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Transcrição Genética
8.
J Pharmacol Exp Ther ; 355(3): 429-41, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26427720

RESUMO

Cytosolic sulfotransferase 1C2 (SULT1C2) is expressed in the kidney, stomach, and liver of rats; however, the mechanisms regulating expression of this enzyme are not known. We evaluated transcriptional regulation of SULT1C2 by mevalonate (MVA)-derived intermediates in primary cultured rat hepatocytes using several cholesterol synthesis inhibitors. Blocking production of mevalonate with the 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor pravastatin (30 µM), reduced SULT1C2 mRNA content by ∼40% whereas the squalene synthase inhibitor squalestatin (SQ1, 0.1 µM), which causes accumulation of nonsterol isoprenoids, increased mRNA content by 4-fold. Treatment with MVA (10 mM) strongly induced SULT1C2 mRNA by 12-fold, and this effect was blocked by inhibiting squalene epoxidase but not by more distal cholesterol inhibitors, indicating the effects of MVA are mediated by postsqualene metabolites. Using rapid amplification of cDNA ends (RACE), we characterized the 5' end of SULT1C2 mRNA and used this information to generate constructs for promoter analysis. SQ1 and MVA increased reporter activity by ∼1.6- and 3-fold, respectively, from a construct beginning 49 base pairs (bp) upstream from the longest 5'-RACE product (-3140:-49). Sequence deletions from this construct revealed a hepatocyte nuclear factor 1 (HNF1) element (-2558), and mutation of this element reduced basal (75%) and MVA-induced (30%) reporter activity and attenuated promoter activation following overexpression of HNF1α or 1ß. However, the effects of SQ1 were localized to a more proximal promoter region (-281:-49). Collectively, our findings demonstrate that cholesterol biosynthetic intermediates influence SULT1C2 expression in rat primary hepatocytes. Further, HNF1 appears to play an important role in mediating basal and MVA-induced SULT1C2 transcription.


Assuntos
Colesterol/biossíntese , Regulação Enzimológica da Expressão Gênica/fisiologia , Hepatócitos/enzimologia , Sulfotransferases/biossíntese , Sulfotransferases/genética , Animais , Anticolesterolemiantes/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Genes Reporter , Fator 1 Nuclear de Hepatócito/genética , Fator 1 Nuclear de Hepatócito/metabolismo , Hepatócitos/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Masculino , Ácido Mevalônico/farmacologia , Cultura Primária de Células , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Esqualeno Mono-Oxigenase/antagonistas & inibidores , Sulfotransferases/efeitos dos fármacos , Transfecção , Ácidos Tricarboxílicos/farmacologia
9.
Drug Metab Pharmacokinet ; 30(2): 188-97, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25989892

RESUMO

Constitutive androstane receptor (CAR) is one of the principal regulators of hepatic cytochrome P450s (CYPs) 3A (CYP3A). cDNA-mediated expression of a mature rat CAR (rCAR) into rat hepatoma cells induced CYP3A1 and CYP2B mRNAs. Aberrant rCAR failed in these inductions. Three important human CYP3A4 regulatory elements (REs), proximal ER6 (proER6), xenobiotic responsive enhancer module (XREM) and constitutive liver enhancer module (CLEM), support constitutive and inducible expression of CYP3As mediated by CAR and pregnane X receptor (PXR). NHR-scan software predicted proER6, XREM and CLEM at -255 b, -8 kb and -11.5 kb, respectively of CYP3A4, but neither XREM nor CLEM was predicted in rat CYP3A. A luciferase reporter construct carrying a 5'-flanking sequence of CYP3A1 (-31,739 to -31,585 from its transcription initiation site) revealed important for the rCAR-dependent transactivation of CYP3A1. This region includes two putative binding motifs of nuclear receptors (DR4 and DR2), a putative hepatocyte nuclear factor-1 binding motif (HNF1), nuclear factor-kappa B binding motif (NFκB), activator protein 1 binding motif (AP-1), and ecotropic viral integration site 1 binding motif (Evi1). We hereby conclude DR4 and/or DR2 motifs being primarily responsible and HNF1 being synergistically functioning elements for the rCAR-mediated transcription of CYP3A1.


Assuntos
Região 5'-Flanqueadora , Citocromo P-450 CYP3A/genética , Hepatócitos/enzimologia , Receptores Citoplasmáticos e Nucleares/genética , Elementos de Resposta , Animais , Sítios de Ligação , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Citocromo P-450 CYP3A/metabolismo , Dexametasona/farmacologia , Regulação Enzimológica da Expressão Gênica , Genes Reporter , Fator 1 Nuclear de Hepatócito/metabolismo , Hepatócitos/efeitos dos fármacos , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/genética , Masculino , Ligação Proteica , RNA Mensageiro/metabolismo , Ratos Endogâmicos F344 , Receptores Citoplasmáticos e Nucleares/metabolismo , Transcrição Genética , Ativação Transcricional , Transfecção , Ácidos Tricarboxílicos/farmacologia
10.
Diabet Med ; 31(6): 721-7, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24905847

RESUMO

AIM: To compare the prevalence and clinical features of HNF1ß-related MODY and HNF1α-related MODY in Japanese. METHODS: We enrolled 230 Japanese patients with suspected MODY and examined them for HNF1α and HNF1ß mutations. We characterized the clinical features of HNF1ß-related MODY (HNF1ß-MODY) and HNF1α-related MODY (HNF1α-MODY). RESULTS: Six patients had HNF1ß mutations, four of which were large gene deletions and 24 patients had HNF1α mutations, which included one gene deletion. The mean fasting plasma glucose level at onset of HNF1ß-MODY was considerably higher and the age of onset of HNF1ß-MODY was considerably older than they were for HNF1α-MODY, while the mean BMI and C-peptide index at onset were similar. Three patients with HNF1ß-MODY were found to have dorsal pancreatic agenesis and four of them had whole-gene deletion. Five of the patients with HNF1ß-MODY had insulin secretion defects and were treated with insulin, and four of these did not have a parent with overt diabetes. CONCLUSION: HNF1ß-MODY may present as ß-cell dysfunction in Japanese rather than as hyperinsulinaemia, which it does among European/American. This dysfunction might result from an intrinsically lower capacity for insulin secretion in Japanese. HNF1ß-MODY has an older age of onset than HNF1α-MODY, which may suggest lower penetrance of the disease. In addition, HNF1ß-MODY has a broad spectrum of clinical manifestations, some of which are detectable by imaging. This may be helpful in some cases for selecting HNF1ß-MODY candidates for genetic testing.


Assuntos
Grupo com Ancestrais do Continente Asiático/genética , Diabetes Mellitus Tipo 2/genética , Fator 1 Nuclear de Hepatócito/genética , Mutação/genética , Adolescente , Adulto , Idade de Início , Análise de Variância , Criança , Feminino , Fator 1-alfa Nuclear de Hepatócito/genética , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
11.
Int J Cancer ; 135(3): 585-97, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24382740

RESUMO

Targeted approaches have revealed frequent epigenetic alterations in ovarian cancer, but the scope and relation of these changes to histologic subtype of disease is unclear. Genome-wide methylation and expression data for 14 clear cell carcinoma (CCC), 32 non-CCC and four corresponding normal cell lines were generated to determine how methylation profiles differ between cells of different histological derivations of ovarian cancer. Consensus clustering showed that CCC is epigenetically distinct. Inverse relationships between expression and methylation in CCC were identified, suggesting functional regulation by methylation, and included 22 hypomethylated (UM) genes and 276 hypermethylated (HM) genes. Categorical and pathway analyses indicated that the CCC-specific UM genes were involved in response to stress and many contain hepatocyte nuclear factor (HNF) 1-binding sites, while the CCC-specific HM genes included members of the estrogen receptor alpha (ERalpha) network and genes involved in tumor development. We independently validated the methylation status of 17 of these pathway-specific genes, and confirmed increased expression of HNF1 network genes and repression of ERalpha pathway genes in CCC cell lines and primary cancer tissues relative to non-CCC specimens. Treatment of three CCC cell lines with the demethylating agent Decitabine significantly induced expression for all five genes analyzed. Coordinate changes in pathway expression were confirmed using two primary ovarian cancer datasets (p < 0.0001 for both). Our results suggest that methylation regulates specific pathways and biological functions in CCC, with hypomethylation influencing the characteristic biology of the disease while hypermethylation contributes to the carcinogenic process.


Assuntos
Adenocarcinoma de Células Claras/genética , Metilação de DNA , Epigenômica , Neoplasias Ovarianas/genética , Adenocarcinoma de Células Claras/patologia , Feminino , Fator 1 Nuclear de Hepatócito/genética , Fator 1 Nuclear de Hepatócito/metabolismo , Humanos , Estadiamento de Neoplasias , Neoplasias Ovarianas/patologia , Reação em Cadeia da Polimerase em Tempo Real , Células Tumorais Cultivadas
12.
J Pharmacol Exp Ther ; 347(1): 181-92, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23922447

RESUMO

The organic cation transporter 1 (OCT1), also known as solute carrier family 22 member 1, is strongly and specifically expressed in the human liver. Here we show that the hepatocyte nuclear factor 1 (HNF1) regulates OCT1 transcription and contributes to the strong, liver-specific expression of OCT1. Bioinformatic analyses revealed strong conservation of HNF1 binding motifs in an evolutionary conserved region (ECR) in intron 1 of the OCT1 gene. Electrophoretic mobility shift and chromatin immunoprecipitation assays confirmed the specific binding of HNF1 to the intron 1 ECR. In reporter gene assays performed in HepG2 cells, the intron 1 ECR increased SV40 promoter activity by 22-fold and OCT1 promoter activity by 13-fold. The increase was reversed when the HNF1 binding sites in the intron 1 ECR were mutated or the endogenous HNF1α expression was downregulated with small interfering RNA. Following HNF1α overexpression in Huh7 cells, the intron 1 ECR increased SV40 promoter activity by 11-fold and OCT1 promoter activity by 6-fold. Without HNF1α overexpression, the increases were only 3- and 2-fold, respectively. Finally, in human liver samples, high HNF1 expression was significantly correlated with high OCT1 expression (r = 0.48, P = 0.002, n = 40). In conclusion, HNF1 is a strong regulator of OCT1 expression. It remains to be determined whether genetic variants, disease conditions, or drugs that affect HNF1 activity may affect the pharmacokinetics and efficacy of OCT1-transported drugs such as morphine, tropisetron, ondansetron, tramadol, and metformin. Beyond OCT1, this study demonstrates the validity and usefulness of interspecies comparisons in the discovery of functionally relevant genomic sequences.


Assuntos
Sequência Conservada/genética , Evolução Molecular , Fator 1 Nuclear de Hepatócito/genética , Íntrons/genética , Transportador 1 de Cátions Orgânicos/biossíntese , Transportador 1 de Cátions Orgânicos/genética , Adolescente , Adulto , Idoso , Animais , Bovinos , Criança , Pré-Escolar , Cães , Feminino , Regulação da Expressão Gênica , Células Hep G2 , Hepatócitos/fisiologia , Humanos , Macaca mulatta , Masculino , Camundongos , Pessoa de Meia-Idade , Pan troglodytes , Ligação Proteica/genética , Ratos , Especificidade da Espécie , Transcrição Genética , Adulto Jovem
13.
Meat Sci ; 94(4): 474-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23628452

RESUMO

The aim of this study was to investigate the association and expression of HNF1A gene as a candidate gene for meat and carcass quality traits in pigs. Statistical analysis revealed that the g.8260 A>G polymorphism significantly associated with pH 24(H), meat percentage and muscle area in the F2 Duroc × Pietrain (DuPi, n=313) and with pH 24(L), fat area and backfat thickness in the Pietrain (Pi, n=110) population. HNF1A mRNA and protein expressions were higher (p<0.05) in animals with the low post-mortem muscle pH 24(L). The promoter methylation profiling suggested that methylation was not involved on HNF1A expression regulation (p>0.05) in animal with divergent muscle pH. In conclusion, polymorphism in porcine HNF1A gene could be used as a candidate marker to improve the meat and carcass quality traits, with the consideration of breed-specific effect.


Assuntos
Tecido Adiposo/metabolismo , Cruzamento , Expressão Gênica , Fator 1 Nuclear de Hepatócito/genética , Carne/análise , Músculo Esquelético/metabolismo , Polimorfismo de Nucleotídeo Único , Animais , Dieta , Gorduras na Dieta/análise , Regulação da Expressão Gênica , Estudos de Associação Genética , Fator 1 Nuclear de Hepatócito/metabolismo , Concentração de Íons de Hidrogênio , Carne/normas , Metilação , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Sus scrofa
14.
J Biosci ; 37(2): 259-67, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22581331

RESUMO

The level of beta-galactoside alpha2,6-sialyltransferase I (ST6Gal I) mRNA, encoded by the gene siat1, is increased in malignant tissues. Expression is regulated by different promoters - P1, P2 and P3 - generating three mRNA isoforms H, X and YZ. In cervical cancer tissue the mRNA isoform H, which results from P1 promoter activity, is increased. To study the regulation of P1 promoter, different constructs from P1 promoter were evaluated by luciferase assays in cervical and hepatic cell lines. Deletion of a fragment of 1048 bp (-89 to +24 bp) increased 5- and 3-fold the promoter activity in C33A and HepG2 cell lines, respectively. The minimal region with promoter activity was a 37 bp fragment in C33A cells. The activity of this region does not require the presence of an initiator sequence. In HepG2 cells the minimal promoter activity was detected in the 66 bp fragment. Sp1 (-32) mutation increased the promoter activity only in HepG2 cells. HNF1 mutation decreased promoter activity in HepG2 cell line but not in C33A cells. We identified a large region that plays a negative regulation role. The regulation of promoter activity is cell type specific. Our study provides new insights into the complex transcriptional regulation of siat1 gene.


Assuntos
Antígenos CD/genética , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Mutação , Sialiltransferases/genética , Neoplasias do Colo do Útero/genética , Antígenos CD/metabolismo , Sequência de Bases , Sítios de Ligação , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Feminino , Expressão Gênica , Células Hep G2 , Fator 1 Nuclear de Hepatócito/genética , Humanos , Neoplasias Hepáticas/metabolismo , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Isoformas de RNA/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sialiltransferases/metabolismo , Fator de Transcrição Sp1/imunologia , Neoplasias do Colo do Útero/enzimologia
15.
Hum Mutat ; 32(10): 1153-60, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21681857

RESUMO

N-acetylglutamate synthase (NAGS) catalyzes the conversion of glutamate and acetyl-CoA to NAG, the essential allosteric activator of carbamyl phosphate synthetase I, the first urea cycle enzyme in mammals. A 17-year-old female with recurrent hyperammonemia attacks, the cause of which remained undiagnosed for 8 years in spite of multiple molecular and biochemical investigations, showed markedly enhanced ureagenesis (measured by isotope incorporation) in response to N-carbamylglutamate (NCG). This led to sequencing of the regulatory regions of the NAGS gene and identification of a deleterious single-base substitution in the upstream enhancer. The homozygous mutation (c.-3064C>A), affecting a highly conserved nucleotide within the hepatic nuclear factor 1 (HNF-1) binding site, was not found in single nucleotide polymorphism databases and in a screen of 1,086 alleles from a diverse population. Functional assays demonstrated that this mutation decreases transcription and binding of HNF-1 to the NAGS gene, while a consensus HNF-1 binding sequence enhances binding to HNF-1 and increases transcription. Oral daily NCG therapy restored ureagenesis in this patient, normalizing her biochemical markers, and allowing discontinuation of alternate pathway therapy and normalization of her diet with no recurrence of hyperammonemia. Inc.


Assuntos
Aminoácido N-Acetiltransferase/genética , Elementos Facilitadores Genéticos , Glutamatos/uso terapêutico , Deleção de Sequência , Distúrbios Congênitos do Ciclo da Ureia/tratamento farmacológico , Distúrbios Congênitos do Ciclo da Ureia/genética , Adolescente , Alelos , Sequência de Bases , Sítios de Ligação , Linhagem Celular Tumoral , Criança , Feminino , Frequência do Gene , Glutamatos/metabolismo , Células Hep G2 , Fator 1 Nuclear de Hepatócito/metabolismo , Humanos , Motivos de Nucleotídeos , Polimorfismo de Nucleotídeo Único , Alinhamento de Sequência , Resultado do Tratamento , Distúrbios Congênitos do Ciclo da Ureia/metabolismo
16.
J Biol Chem ; 286(19): 17259-69, 2011 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-21454713

RESUMO

HDL is a negative risk factor for atherosclerosis because of its multiple atheroprotective functions. Inflammation converts HDL particles from anti-atherogenic to pro-atherogenic, and this transformation is associated with changes in HDL structure and composition. Apolipoprotein M (apoM) has been recently shown to play a role in the maturation of HDL in plasma and to protect from atherosclerosis. ApoM gene is expressed primarily in the liver and kidney and is down-regulated by pro-inflammatory signals. We now show that the human apoM promoter harbors a dual specificity regulatory element in the proximal region that binds hepatocyte nuclear factor 1 (HNF-1) and members of the AP-1 family of pro-inflammatory transcription factors (c-Jun and JunB). Overexpression of c-Jun or JunB repressed both the basal and the HNF-1-mediated transactivation of the human apoM promoter. Treatment of HepG2 cells with potent inflammation-inducing phorbol esters or overexpression of PKCα was associated with a marked inhibition of apoM gene expression in a c-Jun/JunB-dependent manner. We provide evidence for a novel mechanism of inflammation-induced transcriptional repression that is based on the competition between HNF-1 and Jun proteins for binding to the same regulatory region. A similar mechanism accounts for the down-regulation of the liver-specific apolipoprotein A-II gene by Jun factors. Our studies provide novel insights on the mechanisms that control the expression of liver-specific apolipoprotein genes during inflammation and could affect the maturation and the functionality of HDL particles.


Assuntos
Apolipoproteínas/metabolismo , Regulação da Expressão Gênica , Fator 1 Nuclear de Hepatócito/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Apolipoproteínas M , Linhagem Celular , HDL-Colesterol/metabolismo , Humanos , Inflamação , Lipocalinas , Modelos Biológicos , Mutação , Ésteres de Forbol/metabolismo , Regiões Promotoras Genéticas , Fator de Transcrição AP-1/metabolismo , Ativação Transcricional
17.
Front Biosci (Elite Ed) ; 3: 529-39, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21196332

RESUMO

Endometriosis affects an estimated 10% of women in the reproductive-age group. Here, we review current knowledge on molecular genesis of endometriosis-associated epithelial ovarian carcinoma (EOC). This article reviews the English language literature for biology, pathogenesis, and pathophysiological studies on endometriosis-associated EOC. Although endometriosis generally remains a benign condition, it demonstrates somatically acquired genetic alterations. Clear cell carcinoma (CCC) and endometrioid adenocarcinoma (EAC) are the most frequent types of EOC associated with endometriosis. Retrograde menstruation or ovarian hemorrhage carries highly pro-oxidant factors, such as iron, into the peritoneal cavity or ovarian endometrioma. CCC and EAC should be considered separately in studies of endometriosis-associated EOC. The repeated events of hemorrhage in endometriosis can contribute to carcinogenesis and progression via 3 major processes: 1) increasing oxidative stress promotes DNA methylation; 2) activating anti-apoptotic pathways supports tumor promotion; and 3) aberrant expression of stress signaling pathways contributes to tumor progression. This review summarizes recent advances in the understanding of epidemiology, carcinogenesis, pathogenesis, and pathophysiology of endometriosis-associated EOC; and a possible novel model is proposed.


Assuntos
Carcinoma/genética , Carcinoma/fisiopatologia , Endometriose/complicações , Endometriose/fisiopatologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/fisiopatologia , Carcinoma/etiologia , Metilação de DNA/fisiologia , Feminino , Genes do Tumor de Wilms , Genes ras/genética , Hemorragia/etiologia , Hemorragia/fisiopatologia , Fator 1 Nuclear de Hepatócito/genética , Humanos , Perda de Heterozigosidade , Repetições de Microssatélites/genética , Biologia Molecular , Neoplasias Ovarianas/etiologia , Estresse Oxidativo/fisiologia , PTEN Fosfo-Hidrolase/genética , Receptores Estrogênicos/genética , Fatores de Risco , Transdução de Sinais/fisiologia , Estresse Fisiológico/fisiologia
18.
Evol Dev ; 13(1): 38-46, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21210941

RESUMO

The hindbrain is a vertebrate-specific embryonic structure of the central nervous system formed by iterative transitory units called rhombomeres (r). Rhombomeric cells are segregated by interhombomeric boundaries which are prefigured by sharp gene expression borders. The positioning of the first molecular boundary within the hindbrain (the prospective r4/r5 boundary) responds to the expression of an Iroquois (Irx) gene in the anterior (r4) and the gene vHnf1 at the posterior (r5). However, while Irx3 is expressed anteriorly in amniotes, a novel Irx gene, iro7, acts in teleosts. To assess the evolutionary history of the genes responsible for the positioning of the r4/r5 boundary in vertebrates, we have stepped outside the gnathostomes to investigate these genes in the agnathans Lethenteron japonicum and Petromyzon marinus. We identified one representative of the Hnf1 family in agnathans. Its expression pattern recapitulates that of vHnf1 and Hnf1 in higher vertebrates. Our phylogenetic analysis places this gene basal to gnathostome Hnf1 and vHnf1 genes. We propose that the duplication of an ancestral hnf1 gene present in the common ancestor of agnathans and gnathostomes gave rise to the two genes found in gnathostomes. We have also amplified 3 Irx genes in L. japonicum: LjIrxA, LjIrxC, LjIrxD. The expression pattern of LjIrxA (the agnathan Irx1/3 ortholog) resembles those of Irx3 or iro7 in gnathostomes. We propose that an Irx/hnf1 pair already present in early vertebrates positioned the r4/r5 boundary and that gene duplications occurred in these gene families after the divergence of the agnathans.


Assuntos
Evolução Molecular , Proteínas de Peixes/genética , Proteínas de Homeodomínio/genética , Lampreias/embriologia , Lampreias/genética , Rombencéfalo/embriologia , Sequência de Aminoácidos , Animais , Padronização Corporal , Embrião não Mamífero/embriologia , Proteínas de Peixes/metabolismo , Duplicação Gênica , Regulação da Expressão Gênica no Desenvolvimento , Genes Homeobox , Fator 1 Nuclear de Hepatócito/genética , Lampreias/classificação , Dados de Sequência Molecular , Família Multigênica , Petromyzon/classificação , Petromyzon/embriologia , Petromyzon/genética , Filogenia , Alinhamento de Sequência , Vertebrados/embriologia , Vertebrados/genética
19.
J Nutr Biochem ; 22(4): 344-50, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20471816

RESUMO

Ascorbic acid, the active form of vitamin C, is a vital antioxidant in the human liver, yet the molecular mechanisms involved in the regulation of ascorbic acid transporters [human sodium-dependent vitamin C transporters (hSVCT) 1 and 2] in liver cells are poorly understood. Therefore, we characterized the minimal promoter regions of hSVCT1 and 2 in cultured human liver epithelial cells (HepG2) and examined the effects of ascorbic acid deprivation and supplementation on activity and regulation of the transport systems. Identified minimal promoters required for basal activity were found to include multiple cis regulatory elements, whereas mutational analysis demonstrated that HNF-1 sites in the hSVCT1 promoter and KLF/Sp1 sites in the hSVCT2 promoter were essential for activities. When cultured in ascorbic acid deficient or supplemented media, HepG2 cells demonstrated significant (P<.01) and specific reciprocal changes in [(14)C]-Ascorbic acid uptake, and in hSVCT1 mRNA and protein levels as well as hSVCT1 promoter activity. However, no significant changes in hSVCT2 expression or promoter activity were observed during ascorbic acid deficient or supplemented conditions. We mapped the ascorbic acid responsive region in the hSVCT1 promoter and determined that HNF-1 sites are important for the adaptive regulation response. The results of these studies further characterize the hSVCT1 and 2 promoters establish that ascorbic acid uptake by human liver epithelial cells is adaptively regulated and show that transcriptional mechanisms via HNF-1 in the hSVCT1 promoter may, in part, be involved in this regulation.


Assuntos
Transportadores de Ânions Orgânicos Dependentes de Sódio/genética , Simportadores/genética , Ácido Ascórbico/metabolismo , Ácido Ascórbico/farmacologia , Deficiência de Ácido Ascórbico/fisiopatologia , Regulação da Expressão Gênica , Células Hep G2 , Fator 1 Nuclear de Hepatócito/fisiologia , Humanos , Regiões Promotoras Genéticas/fisiologia , Transportadores de Sódio Acoplados à Vitamina C
20.
J Biol Chem ; 286(8): 6049-60, 2011 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-21163946

RESUMO

Resveratrol, a polyphenol compound, is known for its effects on energy homeostasis. With properties of energy sensors mediating effects of calorie restriction, sirtuins are targets of resveratrol. The mammalian sirtuin homolog SIRT1 is a protein deacetylase playing a role in glucose metabolism and islet function. Here, we investigated the effects of resveratrol and possible link with SIRT1 in ß-cells. Insulinoma INS-1E cells and human islets were cultured with resveratrol before analyzing their physiological responses. Treatment of INS-1E cells for 24 h with 25 µM resveratrol resulted in marked potentiation of glucose-stimulated insulin secretion. This effect was associated with elevated glycolytic flux, resulting in increased glucose oxidation, ATP generation, and mitochondrial oxygen consumption. Such changes correlated with up-regulation of key genes for ß-cell function, i.e. Glut2, glucokinase, Pdx-1, Hnf-1α, and Tfam. In human islets, chronic resveratrol treatment similarly increased both the glucose secretory response and expression of the same set of genes, eventually restoring the glucose response in islets obtained from one type 2 diabetic donor. Overexpression of Sirt1 in INS-1E cells potentiated resveratrol effects on insulin secretion. Conversely, inhibition of SIRT1 achieved either by expression of an inactive mutant or by using the EX-527 inhibitor, both abolished resveratrol effects on glucose responses. Treatment of INS-1E cells with EX-527 also prevented resveratrol-induced up-regulation of Glut2, glucokinase, Pdx-1, and Tfam. Resveratrol markedly enhanced the glucose response of INS-1E cells and human islets, even after removal of the compound from the medium. These effects were mediated by and fully dependent on active SIRT1, defining a new role for SIRT1 in the regulation of insulin secretion.


Assuntos
Glucose/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Sirtuína 1/metabolismo , Animais , Carbazóis/farmacologia , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Inibidores Enzimáticos/farmacologia , Glucoquinase/genética , Glucoquinase/metabolismo , Glucose/farmacologia , Transportador de Glucose Tipo 2/genética , Transportador de Glucose Tipo 2/metabolismo , Fator 1 Nuclear de Hepatócito/genética , Fator 1 Nuclear de Hepatócito/metabolismo , Proteínas de Grupo de Alta Mobilidade/genética , Proteínas de Grupo de Alta Mobilidade/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Insulina/genética , Secreção de Insulina , Células Secretoras de Insulina/citologia , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Consumo de Oxigênio/fisiologia , Ratos , Resveratrol , Sirtuína 1/antagonistas & inibidores , Sirtuína 1/genética , Estilbenos/farmacologia , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologia
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