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1.
J Eur Acad Dermatol Venereol ; 36(11): 2172-2180, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35748133

RESUMO

BACKGROUND: Polymorphous light eruption (PLE) is a common, immunologically mediated, photosensitive skin disease. After ultraviolet-B (UV-B) irradiation, patients with PLE show reduced Langerhans cell (LC) depletion in the epidermis, which results in a non-suppressive microenvironment in the skin. Interestingly, severe acute graft-versus-host disease (aGvHD) occurred in stem cell transplanted patients that showed no or incomplete depletion of LCs after UVB irradiation. Genetic variation in nucleotide-binding oligomerization domain 2 (NOD-2) and toll-like receptor 5 (TLR-5) genes also confers susceptibility to aGvHD. OBJECTIVES: We hypothesized that PLE is associated with genetic variation in the NOD-2 and TLR-5 genes. METHODS: We investigated single-nucleotid polymorphisms (SNPs) of NOD-2 (R702W, G908R, 3020Cins) and TLR-5 (A592S, P616L, N392STOP) in skin biopsies of patients with PLE (n = 143) and in healthy controls (n = 104) using restriction fragment length polymorphism analysis. RESULTS: The frequency of NOD-2 alleles with the SNP R702W was significantly higher in PLE than in controls (31.8% vs. 6.3%; P < 0.0001), and homozygous carriers of this mutation were more common in PLE (27.9% vs. 0%; P < 0.0001). For SNP 3020Cins, the allele frequency (7.3% vs. 0.7%; P = 0.0025) and the number of heterozygotes (14.7% vs. 1.3%; P = 0.0019) were higher in PLE. The frequency of alleles with the N392STOP SNP of the TLR5 gene, which is associated with a truncated, non-functional receptor, was significantly higher in PLE (21% vs. 5%; 7% vs. 1% homozygotes, 28% vs. 8% heterozygotes; P < 0.0001). The other SNPs did not differ significantly. CONCLUSIONS: This study yielded a high frequency of functional SNPs in the NOD-2 and TLR-5 genes in PLE. The same SNPs are associated with aGvHD and there are similarities in the reaction of LCs after UVB irradiation between aGvHD and PLE. This leads to the hypothesis that patients with PLE may be more susceptible to developing GvHD after stem cell transplantation, an assumption that needs to be investigated further.


Assuntos
Dermatite de Contato , Proteína Adaptadora de Sinalização NOD2/genética , Transtornos de Fotossensibilidade , Receptor 5 Toll-Like/genética , Humanos , Nucleotídeos , Transtornos de Fotossensibilidade/patologia , Polimorfismo Genético , Raios Ultravioleta/efeitos adversos
2.
Br J Cancer ; 112(5): 841-50, 2015 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-25688743

RESUMO

BACKGROUND: Systemic therapy has proven only marginal effects in hepatocellular carcinoma (HCC) so far. The aim of this study was to evaluate the effect of targeting fibroblast growth factor receptor (FGFR) on tumour and stromal cells in HCC models. METHODS: Human and murine HCC cells, endothelial cells (ECs), vascular smooth muscle cells (VSMCs), hepatic stellate cells (HSCs), human HCC samples, FGFR inhibitor BGJ398 and mammalian target of rapamycin (mTOR) inhibitor rapamycin were used. Effects on growth, motility, signalling and angiogenic markers were determined. In vivo subcutaneous and syngeneic orthotopic tumour models were used. RESULTS: In tumour cells and ECs, targeting FGFR showed significant inhibitory effects on signalling and motility. Minor effects of FGFR inhibition were observed on VSMCs and HSCs, which were significantly enhanced by combining FGFR and mTOR blockade. In vivo daily (5 mg kg(-1)) treatment with BGJ398 led to a significant growth inhibition in subcutaneous tumour models, but only a combination of FGFR and mTOR blockade impaired tumour growth in the orthotopic model. This was paralleled by reduced tumour cell proliferation, vascularisation, pericytes and increased apoptosis. CONCLUSIONS: Targeting FGFR with BGJ398 affects tumour cells and ECs, whereas only a combination with mTOR inhibition impairs recruitment of VSMCs and HSCs. Therefore, this study provides evidence for combined FGFR/mTOR inhibition in HCC.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Compostos de Fenilureia/farmacologia , Pirimidinas/farmacologia , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/antagonistas & inibidores , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Nus , Transplante de Neoplasias , Compostos de Fenilureia/administração & dosagem , Pirimidinas/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Sirolimo/administração & dosagem , Ensaios Antitumorais Modelo de Xenoenxerto
3.
J Hepatol ; 58(2): 254-61, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23041305

RESUMO

BACKGROUND & AIMS: Splanchnic vasodilation is an essential disturbance in portal hypertension. Increased systemic sympathetic nerve activity is well known, but potential corresponding vascular desensitization is incompletely characterized. Release of splanchnic sympathetic neurotransmitters noradrenaline (NA) and co-transmitter neuropeptide Y (NPY) remains to be elucidated. Finally, the effects of exogenous NPY on these mechanisms are unexplored. METHODS: Portal vein ligated cirrhotic, and control rats were used for in vitro perfusion of mesenteric arteries. Depletion of vascular pressure response was induced by repetitive electric sympathetic perivascular nerve stimulation (PNS) and performed in the absence and presence of exogenous NPY. Additionally, PNS-induced release of NA and NPY was measured. RESULTS: Mesenteric PNS-induced pressure response was lower in portal hypertension. Depletion of the pressure response to PNS, representing the degree of desensitization, was enhanced in portal hypertension. NA release was elevated, whereas NPY release was attenuated in cirrhosis. Administration of exogenous NPY led to marked recovery from desensitization and vasoconstrictive improvement in cirrhotic rats, being associated with more pronounced decrease of NA release. CONCLUSIONS: Pronounced depletion of splanchnic arterial pressure-response to repetitive sympathetic nerve stimulation in cirrhosis is partly attributable to altered NA release as well as to deficient NPY release. External NPY restores vascular contractility and attenuates pathologically elevated NA release in the portal hypertensive mesenteric vasculature, revealing post-, and prejunctional effects at the vascular smooth muscle motor endplate; therefore outlining encouraging therapeutic strategies.


Assuntos
Cirrose Hepática/metabolismo , Neuropeptídeo Y/farmacologia , Neurotransmissores/metabolismo , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/metabolismo , Animais , Tetracloreto de Carbono/efeitos adversos , Modelos Animais de Doenças , Estimulação Elétrica , Hipertensão Portal/metabolismo , Hipertensão Portal/fisiopatologia , Cirrose Hepática/induzido quimicamente , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/metabolismo , Artérias Mesentéricas/fisiopatologia , Neuropeptídeo Y/metabolismo , Norepinefrina/metabolismo , Ratos , Ratos Endogâmicos
4.
Horm Metab Res ; 45(11): 795-801, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23996518

RESUMO

It is indefinite whether nonalcoholic steatohepatitis (NASH) results as by-product from general metabolic perturbations and adipokine dysregulations or whether defined dietary factors also play a pathogenetic role. Here, we examine the effects of a modification of dietary lipids in a NASH inducing diet on metabolic changes as well as hepatic steatosis, inflammation, and fibrosis in rats. Male Wistar rats were fed with variations of the atherogenic diet (AD), which induces pathophysiological changes resembling human NASH. Dietary variants (AD without cholesterol, cholate, or choline; change of neutral fat to olive oil or coconut oil) were fed for 8 weeks. Insulin resistance, adipokine profile, liver histology, and lipid content as well as expression of proinflammatory and profibrogenic genes were examined. AD led to clear signs of hepatic steatosis and inflammation together with an increase in TNF and collagen type 1 expression. AD without cholesterol showed markedly less liver damage without changes of insulin action and adipokine profile. AD with olive oil and AD without cholate clearly attenuated hepatic inflammation, whereas fat deposition and features of the metabolic syndrome were increased in these animals. Insulin resistance and hepatic fat deposition per se do not cause significant hepatic inflammation in this rodent model. However, dietary cholesterol is an important causal agent for the development of NASH. Olive oil plays a protective role in this respect, which might be due to the high content of monounsaturated fatty acids.


Assuntos
Fígado Gorduroso/tratamento farmacológico , Resistência à Insulina , Óleos de Plantas/uso terapêutico , Adipocinas/metabolismo , Animais , Colesterol , Dieta , Modelos Animais de Doenças , Fígado Gorduroso/sangue , Fígado Gorduroso/induzido quimicamente , Fígado Gorduroso/genética , Fibrose/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Humanos , Inflamação/genética , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/patologia , Masculino , Hepatopatia Gordurosa não Alcoólica , Azeite de Oliva , Óleos de Plantas/farmacologia , Ratos , Ratos Wistar , Transaminases/metabolismo , Triglicerídeos/sangue , Aumento de Peso/efeitos dos fármacos
5.
Horm Metab Res ; 42(11): 769-74, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20803414

RESUMO

The AMP activated kinase plays an important role in metabolic control, and pharmacologic enhancement of AMPK activity is used to improve insulin resistance. We hypothesized that high dose of folic acid supplementation might improve insulin sensitivity and hepatic inflammation and examined this by a dietary intervention in (a) the high fat fed rat model of the metabolic syndrome, which shows sole hepatic steatosis as well as (b) in rats fed with a high cholesterol, high cholate diet inducing nonalcoholic steatohepatitis (NASH). Male Wistar rats were fed with folic acid supplemented (40 mg/kg) high fat diet [based on lard, fat content 25% (wt/wt)] or NASH inducing diet (containing 15% fat, 1.25% cholesterol, 0.5% sodium cholate). Metabolic profiling was performed by measuring the animals' visceral fat pads, fasting plasma glucose, insulin, and adipokines as well as in vivo insulin tolerance tests. Hepatic steatosis and inflammation were analyzed semiquantitatively by histological analysis. Folic acid supplementation reduced visceral obesity and improved plasma adiponectin levels. In vivo insulin sensitivity was improved, and in HF-FA rats folic acid increased activation of hepatic AMPK. Further, folic acid supplementation improved hepatic inflammation in animals fed with NASH-inducing diet. Dietary folic acid improved parameters of insulin resistance and hepatic inflammation in rodent models. This might be due to an increased AMK activation.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Suplementos Nutricionais , Ácido Fólico/farmacologia , Hepatite/patologia , Resistência à Insulina , Fígado/patologia , Síndrome Metabólica/enzimologia , Animais , Dieta , Modelos Animais de Doenças , Ativação Enzimática/efeitos dos fármacos , Fígado Gorduroso/complicações , Fígado Gorduroso/patologia , Ácido Fólico/administração & dosagem , Células Hep G2 , Hepatite/enzimologia , Humanos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Síndrome Metabólica/sangue , Síndrome Metabólica/complicações , Obesidade/sangue , Obesidade/complicações , Ratos , Ratos Wistar
7.
Differentiation ; 76(7): 784-94, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18177423

RESUMO

Hepatic stellate cells (HSCs) are pericytes of liver sinusoidal endothelial cells (LSECs) and activation of HSC into a myofibroblast-like phenotype (called transdifferentiation) is involved in several hepatic disease processes including neovascularization during liver metastasis, chronic and acute liver injury. While early smooth muscle cell (SMC) differentiation markers including SM alpha-actin and SM22alpha are expressed in a variety of non-SMC, expression of late-stage markers is far more restricted. Here, we found that in addition to early SMC markers, activated rat HSC express a large panel of characteristic late vascular SMC markers including SM myosin heavy chain, h1-calponin and h-caldesmon. Furthermore, myocardin, which is present exclusively in SMCs and cardiomyocytes and controls the transcription of a subset of early and late SMC markers, is highly expressed in activated HSC. We further studied activated HSC in a functional three-dimensional spheroidal co-culture system together with endothelial cells (EC). Co-culture spheroids of EC and SMC differentiate spontaneously and organize into a core of SMC and a surface layer of EC representing an inside-outside model of the physiological assembly of blood vessels. Replacing SMC by in vitro activated HSC resulted in a similar organized spheroid with differentiated, von-Willebrand factor producing, surface lining quiescent human umbilical vein endothelial cell and a core of HSC. In an in vitro angiogenesis assay, activated HSC induced quiescence in vascular EC-the hallmark of vascular SMC function. Co-spheroids of LSEC and activated HSC formed capillary-like sprouts in gel angiogenesis assays expressing the vascular EC marker VE-cadherin. Our findings indicate that activated HSC are capable to adapt a functional SMC phenotype and to induce formation of tubular sprouts by LSEC and vascular endothelial cells. Since tumors and tumor metastasis induce HSC activation, HSC may take part in tumor-induced neoangiogenesis by adapting SMC-like functions.


Assuntos
Células Endoteliais/citologia , Fígado/citologia , Músculo Liso Vascular/citologia , Animais , Biomarcadores/metabolismo , Diferenciação Celular , Técnicas de Cocultura , Células Endoteliais/metabolismo , Humanos , Masculino , Músculo Liso Vascular/metabolismo , Fenótipo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
8.
Gut ; 57(2): 243-51, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17881540

RESUMO

BACKGROUND: Melanoma inhibitory activity 2 (MIA2) is a novel gene of the MIA gene family. The selective expression of MIA2 in hepatocytes is controlled by hepatocyte nuclear factor (HNF) 1 binding sites in the MIA2 promotor. In contrast, in most hepatocellular carcinomas (HCC) MIA2 expression is down-regulated or lost. AIM: In this study we examined the regulation and functional role of MIA2 in hepatocancerogenesis. METHODS AND RESULTS: In HCC cell lines and tissues HNF-1 expression was lower than in primary human hepatocytes (PHH) and corresponding non-tumorous tissue, respectively, and correlated significantly with the down-regulation of MIA2 expression. Re-expression of HNF-1 in HCC cells reinduced MIA2 in HCC cells to similar levels as found in PHH. Further, MIA2 was re-expressed in HCC cell lines by stable transfection, and the generated cell clones revealed a strongly reduced invasive potential and proliferation rate in vitro. In line with these findings treatment of HCC cells with recombinant MIA2 inhibited proliferation and invasion. In nude mice MIA2 re-expressing HCC cells grew significantly slower and revealed a less invasive growth pattern. Immunohistochemical analysis of a tissue microarray containing HCC and corresponding non-cancerous liver tissue of 85 patients confirmed reduced MIA2 expression in HCC. Furthermore, MIA2 negative HCC tissue showed a significantly higher Ki67 labelling index and loss of MIA2 expression correlated significantly with more advanced tumour stages. CONCLUSION: This study presents MIA2 as an inhibitor of HCC growth and invasion both in vitro and in vivo, and consequently, as a tumour suppressor of HCC. Further, our findings indicate a novel mechanism, how loss of HNF-1 expression in HCC affects tumorigenicity via down-regulation of MIA2.


Assuntos
Carcinoma Hepatocelular/genética , Proteínas da Matriz Extracelular/genética , Genes Supressores de Tumor , Neoplasias Hepáticas/genética , Proteínas de Neoplasias/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Neoplasias , Ciclo Celular , Proliferação de Células , Células Cultivadas , Regulação para Baixo , Proteínas da Matriz Extracelular/antagonistas & inibidores , Feminino , Fator 1 Nuclear de Hepatócito/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/antagonistas & inibidores
9.
Oncogene ; 37(7): 897-911, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29059159

RESUMO

Malignant melanoma reveals rapidly increasing incidence and mortality rates worldwide. By now, BRAF inhibition is the standard therapy for advanced melanoma in patients carrying BRAF mutations. However, only approximately 50% of melanoma patients harbor therapeutically attackable BRAF mutations, and overall survival after treatment with BRAF inhibitors is modest. KRAS (Kirsten Rat sarcoma) proteins are acting upstream of BRAF and have a major role in human cancer. Recent approaches awaken the hope to use KRAS inhibition (KRASi) as a clinical tool. In this study, we identified wild-type KRAS as a novel therapeutic target in melanoma. KRASi functions synergistically with BRAF inhibition to reduce melanoma proliferation and to induce apoptosis independently of BRAF mutational status. Moreover, acquired resistance to BRAF inhibitors in melanoma is dependent on dynamic regulation of KRAS expression with subsequent AKT and extracellular-signal regulated kinase activation and can be overcome by KRASi. This suggests KRASi as novel approach in melanoma-alone or in combination with other therapeutic regimes.


Assuntos
Biomarcadores Tumorais/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Melanoma/patologia , Mutação , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias Cutâneas/patologia , Animais , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Seguimentos , Humanos , Masculino , Melanoma/tratamento farmacológico , Melanoma/genética , Camundongos , Camundongos Nus , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Transdução de Sinais , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Melanoma Maligno Cutâneo
10.
J Clin Invest ; 101(4): 802-11, 1998 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-9466975

RESUMO

Although NFkappaB binding activity is induced during liver regeneration after partial hepatectomy, the physiological consequence of this induction is unknown. We have assessed the role of NFkappaB during liver regeneration by delivering to the liver a superrepressor of NFkappaB activity using an adenoviral vector expressing a mutated form of IkappaBalpha. This adenovirus (Ad5IkappaB) was almost exclusively expressed in the liver and inhibited NFkappaB DNA binding activity and transcriptional activity in cultured cells as well as in the liver in vivo. After partial hepatectomy, infection with Ad5IkappaB, but not a control adenovirus (Ad5LacZ), resulted in the induction of massive apoptosis and hepatocytes as demonstrated by histological staining and TUNEL analysis. In addition, infection with Ad5IkappaB but not Ad5LacZ decreased the mitotic index after partial hepatectomy. These two phenomena, increased apoptosis and failure to progress through the cell cycle, were associated with liver dysfunction in animals infected with the Ad5IkappaB but not Ad5LacZ, as demonstrated by elevated serum bilirubin and ammonia levels. Thus, the induction of NFkappaB during liver regeneration after partial hepatectomy appears to be a required event to prevent apoptosis and to allow for normal cell cycle progression.


Assuntos
Apoptose , Proteínas de Ligação a DNA/metabolismo , Proteínas I-kappa B , Regeneração Hepática/fisiologia , Fígado/metabolismo , NF-kappa B/antagonistas & inibidores , Adenoviridae/genética , Animais , Divisão Celular , Linhagem Celular , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Vetores Genéticos , Humanos , Fígado/citologia , Fígado/fisiopatologia , Inibidor de NF-kappaB alfa , Ratos , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
11.
Mol Cell Biol ; 19(6): 4334-42, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10330174

RESUMO

Three fibrillar collagen mRNAs, alpha1(I), alpha2(I), and alpha1(III), are coordinately upregulated in the activated hepatic stellate cell (hsc) in liver fibrosis. These three mRNAs contain sequences surrounding the start codon that can be folded into a stem-loop structure. We investigated the role of this stem-loop structure in expression of collagen alpha1(I) reporter mRNAs in hsc's and fibroblasts. The stem-loop dramatically decreases accumulation of mRNAs in quiescent hsc's and to a lesser extent in activated hsc's and fibroblasts. The stem-loop decreases mRNA stability in fibroblasts. In activated hsc's and fibroblasts, a protein complex binds to the stem-loop, and this binding requires the presence of a 7mG cap on the RNA. Placing the 3' untranslated region (UTR) of collagen alpha1(I) mRNA in a reporter mRNA containing this stem-loop further increases the steady-state level in activated hsc's. This 3' UTR binds alphaCP, a protein implicated in increasing stability of collagen alpha1(I) mRNA in activated hsc's (B. Stefanovic, C. Hellerbrand, M. Holcik, M. Briendl, S. A. Liebhaber, and D. A. Brenner, Mol. Cell. Biol. 17:5201-5209, 1997). A set of protein complexes assembles on the 7mG capped stem-loop RNA, and a 120-kDa protein is specifically cross-linked to this structure. Thus, collagen alpha1(I) mRNA is regulated by a complex interaction between the 5' stem-loop and the 3' UTR, which may optimize collagen production in activated hsc's.


Assuntos
Colágeno/genética , Fragmentos de Peptídeos/genética , Células 3T3 , Adenoviridae/genética , Animais , Linhagem Celular , Sequência Conservada , Genes Reporter , Fígado/metabolismo , Luciferases/metabolismo , Masculino , Camundongos , Modelos Genéticos , Plasmídeos , RNA Mensageiro/química , RNA Mensageiro/fisiologia , Proteínas de Ligação a RNA/fisiologia , Ratos , Ratos Sprague-Dawley , Análise de Sequência de RNA
12.
Mol Cell Biol ; 17(9): 5201-9, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9271398

RESUMO

The hepatic stellate cell (HSC) is the primary cell responsible for the dramatic increase in the synthesis of type I collagen in the cirrhotic liver. Quiescent HSCs contain a low level of collagen alpha1(I) mRNA, while activated HSCs contain about 60- to 70-fold more of this mRNA. The transcription rate of the collagen alpha1(I) gene is only two fold higher in activated HSCs than in quiescent HSCs. In assays using actinomycin D or 5,6-dichlorobenzimidazole riboside collagen alpha1(I) mRNA has estimated half-lives of 1.5 h in quiescent HSCs and 24 h in activated HSCs. Thus, this 16-fold change in mRNA stability is primarily responsible for the increase in collagen alpha1(I) mRNA steady-state level in activated HSCs. We have identified a novel RNA-protein interaction targeted to the C-rich sequence in the collagen alpha1(I) mRNA 3' untranslated region (UTR). This sequence is localized 24 nucleotides 3' to the stop codon. In transient transfection experiments, mutation of this sequence diminished accumulation of an mRNA transcribed from a collagen alpha1(I) minigene and in stable transfections decreased the half-life of collagen alpha1(I) minigene mRNA. Binding to the collagen alpha1(I) 3' UTR is present in cytoplasmic extracts of activated but not quiescent HSCs. It contains as a subunit alphaCP, which is also found in the complex involved in stabilization of alpha-globin mRNA. The auxiliary factors necessary to promote binding of alphaCP to the collagen 3' UTR are distinct from the factors necessary for binding to the alpha-globin sequence. Since alphaCP is expressed in both quiescent and activated HSCs, these auxiliary factors are responsible for the differentially expressed RNA-protein interaction at the collagen alpha1(I) mRNA 3' UTR.


Assuntos
Colágeno/genética , Fígado/citologia , Processamento de Proteína Pós-Traducional , RNA Mensageiro/metabolismo , Animais , Colágeno/metabolismo , Globinas/genética , Globinas/metabolismo , Fígado/metabolismo , Masculino , Proteínas de Ligação a RNA/metabolismo , Ratos , Ratos Sprague-Dawley
13.
Eur J Endocrinol ; 154(2): 333-40, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16452549

RESUMO

OBJECTIVE: Unexplained hepatic iron overload with increased serum ferritin (SF) values has been associated with the insulin resistance syndrome (IRS), defined by the presence of one or more of the following criteria: increased body mass index (BMI), diabetes, hyperlipidemia or hypertension. However, as yet the association between IRS and SF in a representative population has not been investigated. METHODS: The study subjects participated in a nationwide epidemiological survey on metabolic disorders in the adult German population. The 1200 probands included in this study are representative of the German population. To eliminate major causes of secondary iron overload, 114 (9.5%) subjects with excessive alcohol consumption and 16 (1.5%) subjects with serological evidence for hepatitis B or C were excluded. For all remaining 1070 probands, complete clinical data of SF, HbA1c, known diabetes, BMI, cholesterol, high-density lipoprotein-cholesterol and blood pressure were available. RESULTS: SF values were significantly increased in men and women with high BMI (> 25 kg/m2), increased cholesterol (> 200 mg/dl), and increased systolic (> 160 mmHg) blood pressure, in women with diabetes, and in men with increased diastolic (> 95 mmHg) blood pressure. Furthermore, there was a significant correlation between the number of IRS criteria and SF. CONCLUSIONS: This study shows a significant correlation between SF and the presence of IRS criteria in a large representative population. Interestingly, the severity of the IRS seems to be associated with increased SF levels suggesting a causal connection. Further studies are required to investigate the pathophysiological mechanism and consequences of increased SF levels in patients with IRS.


Assuntos
Diabetes Mellitus/sangue , Ferritinas/sangue , Resistência à Insulina/fisiologia , Adulto , Pressão Sanguínea/fisiologia , Índice de Massa Corporal , Colesterol/sangue , Estudos de Coortes , Diabetes Mellitus/fisiopatologia , Feminino , Alemanha , Hemoglobinas Glicadas/metabolismo , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade
14.
Oncogene ; 23(52): 8509-19, 2004 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-15378016

RESUMO

Malignant transformation of melanocytes frequently coincides with loss of E-cadherin expression. Here, we show that loss of E-cadherin leads to induction of nuclear factor kappa B (NFkappaB) activity in melanoma cell lines. Melanoma cells show constitutively active NFkappaB, whereas no activity is found in primary melanocytes. After re-expression of E-cadherin in melanoma cells, strong downregulation of NFkappaB activity was found. Consistently, NFkappaB activity was induced in primary human melanocytes after inhibition of E-cadherin activity by functionally blocking anti-E-cadherin antibodies. Interestingly, re-expression of E-cadherin-blocked p38 MAPK activity and the p38 MAPK inhibitors SB203580 and SB202190 almost completely prevented NFkappaB activation in melanoma cells. Furthermore, cytoplasmatic beta-catenin induced p38 and NFkappaB activation in malignant melanoma. To our knowledge, this is the first report suggesting a correlation between E-cadherin and NFkappaB activity in melanocytes and melanoma cells. In summary, we conclude that loss of E-cadherin and cytoplasmatic beta-catenin induces p38-mediated NFkappaB activation, potentially revealing an important mechanism of tumorigenesis in malignant melanomas.


Assuntos
Caderinas/metabolismo , Melanoma/metabolismo , NF-kappa B/metabolismo , Western Blotting , DNA Antissenso/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Genes Reporter , Humanos , Reação em Cadeia da Polimerase , Fatores de Transcrição da Família Snail , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção , Regulação para Cima
15.
World J Gastroenterol ; 11(38): 6031-7, 2005 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-16273620

RESUMO

AIM: Clinical and experimental data suggest that gut-derived endotoxins are an important pathogenic factors for progression of chronic liver disease. Recently, a C-T (-159) polymorphism in the promoter region of the CD14 gene was detected and found to confer increased CD14 expression and to be associated with advanced alcoholic liver damage. Here, we investigated this polymorphism in patients with less advanced alcoholic liver disease (ALD) and chronic hepatitis C virus (HCV) infection. METHODS: CD14 genotyping was performed by PCR-RFLP analysis in (a) 121 HCV patients, (b) 62 patients with alcohol-associated cirrhosis (Alc-Ci), (c) 118 individuals with heavy alcohol abuse without evidence of advanced liver damage (Alc-w/o Ci), and (d) 247 healthy controls. Furthermore, serum levels of soluble CD14 (sCD14) and transaminases were determined. RESULTS: The TT genotype was significantly more frequent in Alc-Ci compared to Alc-w/o Ci or controls (40.3% vs 23.7% or 24.0%, respectively). In Alc-w/o Ci, serum levels of transaminases did not differ significantly between patients with different CD14 genotypes. In HCV patients, TT-homozygotes had significantly higher sCD14 levels and sCD14 serum levels were significantly higher in patients with advanced fibrosis or cirrhosis. However, no association was found between CD14 genotypes and histological staging or grading. CONCLUSION: Considering serum transaminases as surrogate markers for alcoholic liver damage, the CD14 polymorphism seems to exhibit different effects during the course of ALD. Differences in genotype distribution between cirrhotic HCV patients and alcoholics and the known functional impact of this polymorphism on CD14 expression levels further indicate differences in the pathophysiological role of CD14 and CD14-mediated lipopolysaccharides signal transduction with regard to the stage as well as the type of the underlying liver disease.


Assuntos
Hepatite C Crônica/genética , Hepatite C Crônica/imunologia , Receptores de Lipopolissacarídeos/genética , Hepatopatias Alcoólicas/genética , Hepatopatias Alcoólicas/imunologia , Adulto , Estudos de Casos e Controles , Feminino , Frequência do Gene , Genótipo , Humanos , Receptores de Lipopolissacarídeos/sangue , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos
16.
Biotechniques ; 26(6): 1106-10, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10376150

RESUMO

Hereditary hemochromatosis (HHC) represents an autosomal recessive disease in which increased iron absorption causes iron overload and irreversible tissue damage. The recently detected association between two point mutations in the HFE gene on chromosome 6p and HHC has made it possible to screen for the disease before the onset of irreversible tissue damage. Conventional genetic testing is based on restriction fragment-length polymorphisms (RFLP) using two endonuclease recognition sites in codon 63 or 282, respectively. In this study, we have adapted single-strand conformation polymorphism analysis for capillary electrophoresis (SSCP-CE) to detect homozygote or heterozygote point mutations. Two HFE gene fragments spanning codons 63 and 282 were amplified by a duplex PCR using genomic DNA from peripheral blood or from tissue sections of paraffin-embedded liver biopsies as template. Thereby, rapid genotyping of both HFE mutations was achieved with a single PCR, omitting the need of further analysis by restriction digest. Eighty-five patients with liver disease and/or suspected iron overload were genotyped using SSCP-CE, and all results were verified by conventional RFLP analysis. In summary, SSCP-CE proved to be a reliable, cost-effective, sensitive and rapid method for genotyping HFE mutations. This method will further facilitate high-throughput genetic screening using capillary array electrophoretic devices.


Assuntos
Eletroforese Capilar/métodos , Testes Genéticos/métodos , Hemocromatose/genética , Polimorfismo Conformacional de Fita Simples , Adulto , Idoso , Feminino , Triagem de Portadores Genéticos , Hemocromatose/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Mutação Puntual
17.
Comb Chem High Throughput Screen ; 3(6): 455-66, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11121515

RESUMO

Diagnosis of inherited diseases or cancer predispositions frequently involves determination of specific mutations or polymorphisms. The number of characterized monogenetic and polygenetic diseases is significantly rising every year. As a result, an increasing number of patient samples with a rising complexity of genetic diseases require molecular diagnostics. In order to apply genetic analyses to large groups of patients or population screening, automation of a sensitive and precise method is highly desirable. Capillary electrophoresis (CE) facilitates the development of methods which can rapidly process large number of patient samples in an automated fashion. In contrast, conventional techniques including Southern blotting, sequencing or standard gel electrophoresis are time consuming, cost ineffective and require substantial amounts of each specimen. Robustness, ease of operation, good reproducibility and low cost are the main advantages of CE. Currently, most protocols adapted to automated CE represent (i) analyses of DNA fragment length or DNA restriction patterns (RFLP), (ii) analyses of single-strand conformation polymorphism (SSCP) and (iii) microsatellite analyses. Recently, automated detection of variations in the FRAXA (CGG)n region (fragile X syndrome), LDL receptor gene, p53 gene, MTHFR (methylenetetrahydrofolate reductase) gene, HFE gene and others has been established on CE systems. These applications clearly demonstrate the suitability of CE for high throughput screening in medical applications.


Assuntos
Eletroforese Capilar/métodos , Programas de Rastreamento/métodos , Técnicas de Laboratório Clínico , DNA/química , DNA/genética , Humanos , Polimorfismo de Fragmento de Restrição
18.
Med Klin (Munich) ; 95(11): 603-7, 2000 Nov 15.
Artigo em Alemão | MEDLINE | ID: mdl-11143539

RESUMO

BACKGROUND AND AIM: According to the German consensus statement, the indication for treatment of HCV-RNA-positive chronic hepatitis C is not derived from histopathology but from elevated aminotransferases. The indication for liver biopsy has been discussed controversely. This study aimed at investigating the correlation between different biochemical and virological parameters and histological scores of inflammation and fibrosis in chronic hepatitis C. PATIENTS AND METHODS: In a retrospective study, data of 126 patients with chronic hepatitis C who had undergone liver biopsy between January 1994 and March 1998 were analyzed. Histology was interpreted according to a defined numerical score of inflammation and fibrosis by a single pathologist. Scores of fibrosis and inflammation were correlated with biochemical and virological parameters. RESULTS: Inflammatory grading showed a moderate but significant correlation with ALT (r = 0.33, p < 0.001), whereas staging of fibrosis did not correlate with ALT (r = 0.15). There was no association between grading or staging and HCV genotype (n = 110) or serum viral load (n = 57). Grading and staging showed a significant association with each other (p < 0.0001). CONCLUSION: Aminotransferases as "surrogate markers" reflect more or less the histological inflammatory activity but do not allow any estimation of the extent of fibrosis. Some patients may have a high inflammatory activity with low aminotransferases or high aminotransferases with low inflammatory activity. Virological parameters such as HCV genotype or viral load do not allow an estimation of histological findings. If prior to treatment of chronic hepatitis C liver biopsy is omitted and the decision for treatment depends solely on the measurement of surrogate markers, considerable misjudgement of the actual status of liver inflammation or fibrosis may result.


Assuntos
Hepacivirus/genética , Hepatite C Crônica/diagnóstico , Testes de Função Hepática , Fígado/patologia , RNA Viral/sangue , Adolescente , Adulto , Idoso , Biópsia , Feminino , Genótipo , Hepatite C Crônica/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
19.
J Viral Hepat ; 13(9): 571-3, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16907842

RESUMO

Chronic hepatitis C patients are advised not to share toothbrushes, razors, nail-scissors or other personal articles that potentially may have been in contact with blood, with others. This study examines the contamination of toothbrushes in patients with chronic hepatitis C as a model for a possible unconventional way of transmission. In 30 patients with chronic hepatitis C, 2 mL of saliva (before and after toothbrushing) and the toothbrush rinsing water after toothbrushing were tested for HCV-RNA. Saliva before and after toothbrushing was positive for HCV-RNA in nine (30%) and 11 patients (36.7%), respectively. Twelve of the toothbrush rinsing water specimens (40%) tested HCV-RNA-positive. In six of these 12 patients, the 'native' saliva had been negative for HCV-RNA. Patients with HCV-RNA-positive toothbrush rinsing water showed no significant differences from those with negative rinsing water with respect to certain clinical, biochemical and virological parameters. In conclusion, our study demonstrates a contamination with HCV-RNA of a considerable portion of toothbrushes used by hepatitis C patients, suggesting at least a theoretical risk of infection by sharing these objects and strengthening the recommendations to take care of a clear separation of these personal care objects between patients and their household members.


Assuntos
Hepacivirus/isolamento & purificação , Hepatite C Crônica/transmissão , Saliva/virologia , Escovação Dentária/instrumentação , Alanina Transaminase/sangue , Bilirrubina/sangue , Feminino , Hepatite C Crônica/virologia , Histocitoquímica , Humanos , Masculino , RNA Viral/análise , Estatística como Assunto , Carga Viral
20.
Histopathology ; 47(1): 57-66, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15982324

RESUMO

AIMS: To determine the expression of a protein termed augmenter of liver regeneration (ALR), recently found to have a specific and beneficial effect on the process of liver regeneration in normal and diseased human liver. METHODS AND RESULTS: ALR expression in normal and cirrhotic human livers with various underlying diseases as well as in tissue samples of hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) was analysed by immunohistochemistry and quantitative reverse transciptase-polymerase chain reaction (RT-PCR). Expression analysis of ALR in total liver protein extracts by Western blotting showed mainly dimeric ALR protein. Immunohistochemically, cytosolic and perinuclear immunosignals were found in hepatocytes and cholangiocytes in normal, cirrhotic or cancerous liver tissue and only weak signals in some endothelial cells in normal livers. Quantitative mRNA analysis revealed significantly increased ALR expression in cirrhosis compared with normal liver tissue. In HCC and CCC ALR mRNA expression was also significantly enhanced compared with normal liver tissue, but expression levels did not differ from the matching non-neoplastic tissue in the same patient. CONCLUSIONS: The findings suggest an important role for ALR in hepatocellular regeneration in liver cirrhosis as well as in hepatocarcinogenesis and therefore its potential value in the clinical diagnosis of hepatic cirrhosis and cancer.


Assuntos
Carcinoma Hepatocelular/patologia , Redutases do Citocromo/genética , Fator de Crescimento de Hepatócito/genética , Cirrose Hepática/patologia , Neoplasias Hepáticas/patologia , Idoso , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos/metabolismo , Ductos Biliares Intra-Hepáticos/patologia , Western Blotting , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Colangiocarcinoma/genética , Colangiocarcinoma/metabolismo , Colangiocarcinoma/patologia , Redutases do Citocromo/metabolismo , Feminino , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Imuno-Histoquímica , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Pessoa de Meia-Idade , Oxirredutases atuantes sobre Doadores de Grupo Enxofre , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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