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1.
Artigo em Inglês | MEDLINE | ID: mdl-33537908

RESUMO

PURPOSE: This retrospective analysis focuses on treatment stage migration in patients with hepatocellular carcinoma (HCC) to identify successful treatment sequences in a large cohort of real-world patients. METHODS: 1369 HCC patients referred from January 1993 to January 2020 to the tertiary center of the Heidelberg University Hospital, Germany were analyzed for initial and subsequent treatment patterns, and overall survival. RESULTS: The most common initial treatment was transarterial chemoembolization (TACE, n = 455, 39.3%) followed by hepatic resection (n = 303, 26.1%) and systemic therapy (n = 200, 17.3%), whereas the most common 2nd treatment modality was liver transplantation (n = 215, 33.2%) followed by systemic therapy (n = 177, 27.3%) and TACE (n = 85, 13.1%). Kaplan-Meier analysis revealed by far the best prognosis for liver transplantation recipients (median overall survival not reached), followed by patients with hepatic resection (11.1 years). Patients receiving systemic therapy as their first treatment had the shortest median overall survival (1.7 years; P < 0.0001). When three or more treatment sequences preceded liver transplantation, patients had a significant shorter median overall survival (1st seq.: not reached; 2nd seq.: 12.4 years; 3rd seq.: 11.1 years; beyond 3 sequences: 5.5 years; P = 0.01). CONCLUSION: TACE was the most common initial intervention, whereas liver transplantation was the most frequent 2nd treatment. While liver transplantation and hepatic resection were associated with the best median overall survival, the timing of liver transplantation within the treatment sequence strongly affected median survival.

2.
JAMA Netw Open ; 3(9): e2015205, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32870313

RESUMO

Importance: Increasing diversity in the physician workforce is a fulcrum for reducing health disparities. Efforts to increase the diversity in the internal medicine (IM) workforce may improve health equity among an increasingly diverse population with increasing prevalence of chronic disease. Objectives: To assess diversity trends in the academic IM workforce and evaluate how well these trends reflected medical student diversity and the changing demographic composition of the general population. Design, Setting, and Participants: This secondary analysis of a cross-sectional study analyzed data from January 1, 1980, to December 31, 2018, from the Association of American Medical Colleges Faculty Roster and Applicant Matriculant File, which capture full-time US medical school faculty and matriculants, respectively, and population data through 2017 from the US Census Bureau. Main Outcomes and Measures: The study calculated the proportions of women and individuals from racial/ethnic groups that are traditionally underrepresented in medicine (URM) among IM faculty and faculty in all other clinical departments. These data were compared with the proportions of female and URM matriculants in US medical schools and the proportions of women and individuals from underrepresented racial/ethnic groups in the population. The analysis was stratified by sex, race/ethnicity, and intersections of sex and race/ethnicity. Results: From 1980 to 2018, the absolute number of full-time IM faculty increased from 10 964 to 42 547. Although IM was the department classification with the most women faculty, in 2018 it continued to have a lower proportion of women (n = 17 165 [40.3%]) compared with all other clinical departments (n = 48 936 [43.2%]). Among IM faculty, the percentage of URM faculty members more than doubled during the study period (from 4.1% to 9.7%) but still made up only a small portion of faculty members. The percentage of female matriculants among medical school matriculants increased steadily (from 28.7% in 1980 to 51.6% in 2018) and was nearly identical to their population representation in 2017 (50.7% compared with 50.8%). Although the percentage of URM matriculants had nearly doubled since 1980 (from 11.3% to 18.1%), it still lagged far behind the proportion of individuals in the US population who are members of underrepresented racial/ethnic groups (18.1% vs 31.5% in 2017). Conclusions and Relevance: This cross-sectional study found that progress has been made in diversifying academic IM faculty; however, it does not yet reflect the diversity of medical students or the US population. Continued efforts to increase the diversity of the academic IM workforce are needed.

3.
Cell Stem Cell ; 27(4): 590-604.e9, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32730753

RESUMO

Although the Hippo transcriptional coactivator YAP is considered oncogenic in many tissues, its roles in intestinal homeostasis and colorectal cancer (CRC) remain controversial. Here, we demonstrate that the Hippo kinases LATS1/2 and MST1/2, which inhibit YAP activity, are required for maintaining Wnt signaling and canonical stem cell function. Hippo inhibition induces a distinct epithelial cell state marked by low Wnt signaling, a wound-healing response, and transcription factor Klf6 expression. Notably, loss of LATS1/2 or overexpression of YAP is sufficient to reprogram Lgr5+ cancer stem cells to this state and thereby suppress tumor growth in organoids, patient-derived xenografts, and mouse models of primary and metastatic CRC. Finally, we demonstrate that genetic deletion of YAP and its paralog TAZ promotes the growth of these tumors. Collectively, our results establish the role of YAP as a tumor suppressor in the adult colon and implicate Hippo kinases as therapeutic vulnerabilities in colorectal malignancies.

4.
JAMA Cardiol ; 4(10): 1029-1033, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31509160

RESUMO

Importance: Increasing cardiology workforce diversity will expand the talent of the applicant pool and may reduce health care disparities. Objective: To assess US cardiology physician workforce demographics by sex and race/ethnicity in the context of the US population and the available pipelines of trainees. Design, Setting, and Participants: This cross-sectional study used data from the Association of American Medical Colleges, the American Medical Association, and the American Board of Internal Medicine to stratify medical students, resident physicians, fellows, and cardiologists by sex and race/ethnicity. Additionally, proportional changes from 2006 through 2016 were assessed for adult and pediatric cardiology. Data analysis took place from August 2018 to January 2019. Main Outcomes and Measures: Percentage of cardiologists and trainees by sex and race/ethnicity in 2016, as well as changes in proportions between 2006 and 2016. Results: Despite a high percentage of female internal medicine resident physicians (10 765 of 25 252 [42.6%]), female physicians were underrepresented in adult general cardiology fellowships (584 of 2720 [21.5%]) and procedural subspecialty fellowships (interventional cardiology, 30 of 305 [9.8%]; electrophysiology, 24 of 175 [13.7%]). The percentage of female adult cardiologists slightly increased from 2006 through 2016 (from 8.9% to 12.6%; slope, 0.36; P < .001) but remained low. Female physicians made up a disproportionately higher number of pediatric residency positions (6439 of 8832 [72.9%]). Trends showed an increase in female pediatric cardiology fellows (from 40.4% to 50.5%; slope, 1.25; P < .001), which resulted in an increase in the percentage of female pediatric cardiologists (from 27.1% to 34.0%; slope, 0.64; P < .001). The percentages of members of underrepresented minority groups in adult and pediatric cardiology fellowships (from 11.1% to 12.4%; slope, 0.15; P = .01; and from 7.7% to 9.9%; slope, 0.29; P = .009; respectively) were low and increased only slightly over time. Additionally, members of underrepresented minorities made up less than 8% of practicing adult and pediatric cardiologists. Although Asian individuals are 5.2% of the US general population, they are not considered underrepresented because they are 22.1% of US medical school graduates (n = 4202 of 18 999), 38.1% of internal medicine resident physicians (n = 9618 of 25 252), 40.4% of adult cardiology fellows (n = 1098 of 2720), 19.9% of adult cardiologists (n = 5973 of 30 016), 22.6% of pediatric resident physicians (n = 1998 of 8832), 28.0% of pediatric cardiology fellows (n = 122 of 436), and 20.1% of pediatric cardiologists (n = 574 of 2860). Conclusions and Relevance: Female physicians remain underrepresented in adult cardiology, despite a robust pipeline of female medical students and internal medicine resident physicians. Women in pediatric cardiology are underrepresented but increasing in number. Members of several racial/ethnic minority groups remain underrepresented in adult and pediatric cardiology, and the percentages of trainees and medical students from these groups were also low. Different strategies are needed to address the continuing lack of diversity in cardiology for underrepresented minority individuals and women.


Assuntos
Cardiologistas/estatística & dados numéricos , Disparidades em Assistência à Saúde/tendências , Sistema de Registros , Autorrelato , Recursos Humanos/estatística & dados numéricos , Feminino , Humanos , Masculino , Estudos Retrospectivos , Sociedades Médicas , Estados Unidos
5.
Cell Stem Cell ; 25(1): 23-38.e8, 2019 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-31080134

RESUMO

The liver can substantially regenerate after injury, with both main epithelial cell types, hepatocytes and biliary epithelial cells (BECs), playing important roles in parenchymal regeneration. Beyond metabolic functions, BECs exhibit substantial plasticity and in some contexts can drive hepatic repopulation. Here, we performed single-cell RNA sequencing to examine BEC and hepatocyte heterogeneity during homeostasis and after injury. Instead of evidence for a transcriptionally defined progenitor-like BEC cell, we found significant homeostatic BEC heterogeneity that reflects fluctuating activation of a YAP-dependent program. This transcriptional signature defines a dynamic cellular state during homeostasis and is highly responsive to injury. YAP signaling is induced by physiological bile acids (BAs), required for BEC survival in response to BA exposure, and is necessary for hepatocyte reprogramming into biliary progenitors upon injury. Together, these findings uncover molecular heterogeneity within the ductal epithelium and reveal YAP as a protective rheostat and regenerative regulator in the mammalian liver.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ciclo Celular/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Células Epiteliais/metabolismo , Hepatócitos/fisiologia , Fígado/patologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Proteínas de Ciclo Celular/genética , Proliferação de Células , Autorrenovação Celular , Doença Hepática Induzida por Substâncias e Drogas/patologia , Modelos Animais de Doenças , Células Epiteliais/patologia , Feminino , Homeostase , Humanos , Regeneração Hepática , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Piridinas/toxicidade , Transdução de Sinais , Análise de Célula Única
6.
Cell Rep ; 25(5): 1304-1317.e5, 2018 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-30380420

RESUMO

Hippo signaling has been recognized as a key tumor suppressor pathway. Here, we perform a comprehensive molecular characterization of 19 Hippo core genes in 9,125 tumor samples across 33 cancer types using multidimensional "omic" data from The Cancer Genome Atlas. We identify somatic drivers among Hippo genes and the related microRNA (miRNA) regulators, and using functional genomic approaches, we experimentally characterize YAP and TAZ mutation effects and miR-590 and miR-200a regulation for TAZ. Hippo pathway activity is best characterized by a YAP/TAZ transcriptional target signature of 22 genes, which shows robust prognostic power across cancer types. Our elastic-net integrated modeling further reveals cancer-type-specific pathway regulators and associated cancer drivers. Our results highlight the importance of Hippo signaling in squamous cell cancers, characterized by frequent amplification of YAP/TAZ, high expression heterogeneity, and significant prognostic patterns. This study represents a systems-biology approach to characterizing key cancer signaling pathways in the post-genomic era.


Assuntos
Neoplasias/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Sequência de Bases , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Modelos Biológicos , Mutação/genética , Prognóstico , Transdução de Sinais/genética
7.
Nat Commun ; 9(1): 4834, 2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30446657

RESUMO

The Hippo-YAP signaling pathway is a critical regulator of proliferation, apoptosis, and cell fate. The main downstream effector of this pathway, YAP, has been shown to be misregulated in human cancer and has emerged as an attractive target for therapeutics. A significant insufficiency in our understanding of the pathway is the identity of transcriptional targets of YAP that drive its potent growth phenotypes. Here, using liver cancer as a model, we identify NUAK2 as an essential mediator of YAP-driven hepatomegaly and tumorigenesis in vivo. By evaluating several human cancer cell lines we determine that NUAK2 is selectively required for YAP-driven growth. Mechanistically, we found that NUAK2 participates in a feedback loop to maximize YAP activity via promotion of actin polymerization and myosin activity. Additionally, pharmacological inactivation of NUAK2 suppresses YAP-dependent cancer cell proliferation and liver overgrowth. Importantly, our work here identifies a specific, potent, and actionable target for YAP-driven malignancies.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Carcinogênese/genética , Carcinoma Hepatocelular/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , Fosfoproteínas/genética , Proteínas Serina-Treonina Quinases/genética , Actinas/genética , Actinas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Antineoplásicos/farmacologia , Benzodiazepinonas/farmacologia , Carcinogênese/efeitos dos fármacos , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Retroalimentação Fisiológica , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Nus , Miosinas/genética , Miosinas/metabolismo , Fosfoproteínas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Ensaios Antitumorais Modelo de Xenoenxerto
8.
EMBO J ; 37(17)2018 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-30037824

RESUMO

The mammalian Hippo signaling pathway, through its effectors YAP and TAZ, coerces epithelial progenitor cell expansion for appropriate tissue development or regeneration upon damage. Its ability to drive rapid tissue growth explains why many oncogenic events frequently exploit this pathway to promote cancer phenotypes. Indeed, several tumor types including basal cell carcinoma (BCC) show genetic aberrations in the Hippo (or YAP/TAZ) regulators. Here, we uncover that while YAP is dispensable for homeostatic epidermal regeneration, it is required for BCC development. Our clonal analyses further demonstrate that the few emerging Yap-null dysplasia have lower fitness and thus are diminished as they progress to invasive BCC Mechanistically, YAP depletion in BCC tumors leads to effective impairment of the JNK-JUN signaling, a well-established tumor-driving cascade. Importantly, in this context, YAP does not influence canonical Wnt or Hedgehog signaling. Overall, we reveal Hippo signaling as an independent promoter of BCC pathogenesis and thereby a viable target for drug-resistant BCC.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adenocarcinoma/metabolismo , Resistencia a Medicamentos Antineoplásicos , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Fator de Transcrição AP-1/metabolismo , Via de Sinalização Wnt , Proteínas Adaptadoras de Transdução de Sinal/genética , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Proteínas de Ciclo Celular , MAP Quinase Quinase 4/genética , MAP Quinase Quinase 4/metabolismo , Camundongos , Camundongos Knockout , Fosfoproteínas/genética , Proteínas Proto-Oncogênicas c-jun/genética , Fator de Transcrição AP-1/genética
9.
Healthc (Amst) ; 6(1): 13-16, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28602803

RESUMO

BACKGROUND: Given the growing roles of nurse practitioners (NPs) and physician assistants (PAs), patients are increasingly able to choose their primary care provider type. Studies examining patient preferences among provider types are limited and ours is the first to examine reasons for patients' provider type preferences. METHODS: Using data from the 2014 Association of American Medical Colleges' (AAMC) Consumer Survey of Health Care Access, we used qualitative analysis to identify themes in open text responses of reasons for respondents' provider type preference (N = 4220). After coding responses for themes, we used chi-square tests to assess whether there were statistically significant differences in respondents' reasons for their provider preference, and whether reasons vary by the gender, race, or age of the respondent. RESULTS: Those preferring physicians were more likely to cite physician qualifications (75%) and trust (7%) than those preferring NP/PAs (qualifications = 36%; trust = 4%). Those preferring NP/PAs were more likely to cite bedside manner (20%) and convenience (9%) than those preferring physicians (bedside manner = 5%; convenience = 4%). Both groups of respondents were equally likely to mention previous experience with their provider type as a reason for their preference (prefer physician = 19%; prefer NP/PA = 21%). CONCLUSIONS: Provider qualifications and previous health care experiences are cited as key reasons for preferring all provider types. Additionally, physicians are more often preferred for their qualifications and technical skills, whereas NP/PAs are more often preferred for their interpersonal skills. IMPLICATIONS: Our results could help providers, health system administrators, workforce planners, and policy makers better understand patient perspectives and design care that enhances patient satisfaction.


Assuntos
Comportamento do Consumidor , Profissionais de Enfermagem/estatística & dados numéricos , Assistentes Médicos/estatística & dados numéricos , Atenção Primária à Saúde , Adolescente , Adulto , Idoso , Distribuição de Qui-Quadrado , Comportamento de Escolha , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Atenção Primária à Saúde/estatística & dados numéricos , Relações Profissional-Paciente , Sociedades/estatística & dados numéricos , Sociedades/tendências , Especialização/estatística & dados numéricos , Inquéritos e Questionários , Confiança/psicologia , Recursos Humanos
10.
PLoS One ; 12(8): e0183443, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28820892

RESUMO

An association between maternal IgG antibodies reactive against proteins in fetal brain and an outcome of autism in the child has been identified. Using a mouse model of prenatal intraventricular administration of autism-specific maternal IgG, we demonstrated that these antibodies produce behavioral alterations similar to those in children with ASD. We previously demonstrated that these antibodies bind to radial glial stem cells (RG) and observed an increase in the number of divisions of translocating RG in the developing cortex. We also showed an alteration in brain size and as well as a generalized increased of neuronal volume in adult mice. Here, we used our intraventricular mouse model of antibody administration, followed by Golgi and Neurolucida analysis to demonstrate that during midstages of neurogenesis these maternal autism-specific antibodies produced a consistent decrease in the number of spines in the infragranular layers in the adult cortical areas analyzed. Specifically, in the frontal cortex basal dendrites of layer V neurons were decreased in length and volume, and both the total number of spines-mature and immature-and the spine density were lower than in the control neurons from the same region. Further, in the occipital cortex layer VI neurons presented with a decrease in the total number of spines and in the spine density in the apical dendrite, as well as decrease in the number of mature spines in the apical and basal dendrites. Interestingly, the time of exposure to these antibodies (E14.5) coincides with the generation of pyramidal neurons in layer V in the frontal cortex and in layer VI in the occipital cortex, following the normal rostro-caudal pattern of cortical cell generation. We recently demonstrated that one of the primary antigens recognized by these antibodies corresponds to stress-induced phosphoprotein 1 (STIP1). Here we hypothesize that the reduction in the access of newborn cells to STIP1 in the developing cortex may be responsible for the reduced dendritic arborization and number of spines we noted in the adult cortex.


Assuntos
Autoanticorpos/imunologia , Córtex Cerebral/imunologia , Espinhas Dendríticas/imunologia , Animais , Córtex Cerebral/citologia , Feminino , Camundongos , Gravidez
11.
Mov Disord ; 32(4): 585-591, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28233916

RESUMO

BACKGROUND: Fragile X-associated tremor/ataxia syndrome is an adult-onset disorder associated with premutation alleles of the FMR1 gene. This disorder is characterized by progressive action tremor, gait ataxia, and cognitive decline. Fragile X-associated tremor/ataxia syndrome pathology includes dystrophic white matter and intranuclear inclusions in neurons and astrocytes. We previously demonstrated that the transport of iron into the brain is altered in fragile X-associated tremor/ataxia syndrome; therefore, we also expect an alteration of iron metabolism in brain areas related to motor control. Iron is essential for cell metabolism, but uncomplexed iron leads to oxidative stress and contributes to the development of neurodegenerative diseases. We investigated a potential iron modification in the putamen - a structure that participates in motor learning and performance - in fragile X-associated tremor/ataxia syndrome. METHODS: We used samples of putamen obtained from 9 fragile X-associated tremor/ataxia syndrome and 9 control cases to study iron localization using Perl's method, and iron-binding proteins using immunostaining. RESULTS: We found increased iron deposition in neuronal and glial cells in the putamen in fragile X-associated tremor/ataxia syndrome. We also found a generalized decrease in the amount of the iron-binding proteins transferrin and ceruloplasmin, and decreased number of neurons and glial cells that contained ceruloplasmin. However, we found increased levels of iron, transferrin, and ceruloplasmin in microglial cells, indicating an attempt by the immune system to remove the excess iron. CONCLUSIONS: Overall, found a deficit in proteins that eliminate extra iron from the cells with a concomitant increase in the deposit of cellular iron in the putamen in Fragile X-associated tremor/ataxia syndrome. © 2017 International Parkinson and Movement Disorder Society.


Assuntos
Ataxia/patologia , Síndrome do Cromossomo X Frágil/patologia , Ferro/metabolismo , Putamen/metabolismo , Tremor/patologia , Astrócitos/metabolismo , Astrócitos/patologia , Ataxia/genética , Estudos de Casos e Controles , Cerebelo/patologia , Ceruloplasmina/metabolismo , Proteína do X Frágil de Retardo Mental/genética , Síndrome do Cromossomo X Frágil/genética , Humanos , Masculino , Transferrina/metabolismo , Tremor/genética
14.
J Pathol Clin Res ; 2(2): 80-92, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27499918

RESUMO

Molecular classification of hepatocellular carcinomas (HCC) could guide patient stratification for personalized therapies targeting subclass-specific cancer 'driver pathways'. Currently, there are several transcriptome-based molecular classifications of HCC with different subclass numbers, ranging from two to six. They were established using resected tumours that introduce a selection bias towards patients without liver cirrhosis and with early stage HCCs. We generated and analyzed gene expression data from paired HCC and non-cancerous liver tissue biopsies from 60 patients as well as five normal liver samples. Unbiased consensus clustering of HCC biopsy profiles identified 3 robust classes. Class membership correlated with survival, tumour size and with Edmondson and Barcelona Clinical Liver Cancer (BCLC) stage. When focusing only on the gene expression of the HCC biopsies, we could validate previously reported classifications of HCC based on expression patterns of signature genes. However, the subclass-specific gene expression patterns were no longer preserved when the fold-change relative to the normal tissue was used. The majority of genes believed to be subclass-specific turned out to be cancer-related genes differentially regulated in all HCC patients, with quantitative rather than qualitative differences between the molecular subclasses. With the exception of a subset of samples with a definitive ß-catenin gene signature, biological pathway analysis could not identify class-specific pathways reflecting the activation of distinct oncogenic programs. In conclusion, we have found that gene expression profiling of HCC biopsies has limited potential to direct therapies that target specific driver pathways, but can identify subgroups of patients with different prognosis.

15.
Lab Invest ; 96(9): 972-80, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27428080

RESUMO

Notch signaling pathways have recently been implicated in the pathogenesis of metabolic diseases. However, the role of hepatic Notch signaling in glucose and lipid metabolism remains unclear and needs further investigation as it might be a candidate therapeutic target in metabolic diseases such as nonalcoholic steatohepatitis (NASH) and nonalcoholic fatty liver disease (NAFLD). We used hepatocyte-specific Notch1 knockout (KO) mice and liver biopsies from NASH and NAFLD patients to analyze the role of Notch1 in glucose and lipid metabolism. Hepatocyte-specific Notch1 KO mice were fed with a high fat diet (HFD) or a regular diet (RD). We assessed the metabolic phenotype, glucose and insulin tolerance tests, and liver histology. Hepatic mRNA expression was profiled by Affymetrix Mouse Gene arrays and validated by quantitative reverse transcription PCR (qPCR). Akt phosphorylation was visualized by immunoblotting. Gene expression was analyzed in liver biopsies from NASH, NAFLD, and control patients by qPCR. We found that Notch1 KO mice had elevated fasting glucose. Gene expression analysis showed an upregulation of glucose-6-phosphatase, involved in the final step of gluconeogenesis and glucose release from glycogenolysis, and perilipin-5, a regulator of hepatic lipid accumulation. When fed with an HFD KO mice developed overt diabetes and hepatic steatosis. Akt was highly phosphorylated in KO animals and the Foxo1 target gene expression was altered. Accordingly, a reduction in Notch1 and increase in glucose-6-phosphatase and perilipin-5 expression was observed in liver biopsies from NAFLD/NASH compared with controls. Notch1 is a regulator of hepatic glucose and lipid homeostasis. Hepatic impairment of Notch1 expression may be involved in the pathogenesis of human NAFLD/NASH.


Assuntos
Diabetes Mellitus/genética , Fígado Gorduroso/genética , Predisposição Genética para Doença/genética , Glucose-6-Fosfatase/genética , Perilipina-1/genética , Receptor Notch1/genética , Animais , Diabetes Mellitus/etiologia , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/etiologia , Perfilação da Expressão Gênica/métodos , Hepatócitos/metabolismo , Humanos , Immunoblotting , Fígado/metabolismo , Fígado/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/genética , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor Notch1/deficiência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para Cima
16.
Nat Cell Biol ; 18(5): 467-79, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27088858

RESUMO

LGR4/5 receptors and their cognate RSPO ligands potentiate Wnt/ß-catenin signalling and promote proliferation and tissue homeostasis in epithelial stem cell compartments. In the liver, metabolic zonation requires a Wnt/ß-catenin signalling gradient, but the instructive mechanism controlling its spatiotemporal regulation is not known. We have now identified the RSPO-LGR4/5-ZNRF3/RNF43 module as a master regulator of Wnt/ß-catenin-mediated metabolic liver zonation. Liver-specific LGR4/5 loss of function (LOF) or RSPO blockade disrupted hepatic Wnt/ß-catenin signalling and zonation. Conversely, pathway activation in ZNRF3/RNF43 LOF mice or with recombinant RSPO1 protein expanded the hepatic Wnt/ß-catenin signalling gradient in a reversible and LGR4/5-dependent manner. Recombinant RSPO1 protein increased liver size and improved liver regeneration, whereas LGR4/5 LOF caused the opposite effects, resulting in hypoplastic livers. Furthermore, we show that LGR4(+) hepatocytes throughout the lobule contribute to liver homeostasis without zonal dominance. Taken together, our results indicate that the RSPO-LGR4/5-ZNRF3/RNF43 module controls metabolic liver zonation and is a hepatic growth/size rheostat during development, homeostasis and regeneration.


Assuntos
Fígado/citologia , Receptores Acoplados a Proteínas-G/metabolismo , Trombospondinas/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Animais Recém-Nascidos , Linhagem da Célula , Proliferação de Células , Citocromo P-450 CYP2E1/metabolismo , Deleção de Genes , Hepatócitos/citologia , Hepatócitos/metabolismo , Homeostase , Antígeno Ki-67/metabolismo , Fígado/crescimento & desenvolvimento , Fígado/metabolismo , Regeneração Hepática , Tamanho do Órgão , Transdução de Sinais , beta-Galactosidase/metabolismo
17.
Hepatology ; 62(5): 1497-510, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26173433

RESUMO

UNLABELLED: The Yes-associated protein (YAP)/Hippo pathway has been implicated in tissue development, regeneration, and tumorigenesis. However, its role in cholangiocarcinoma (CC) is not established. We show that YAP activation is a common feature in CC patient biopsies and human CC cell lines. Using microarray expression profiling of CC cells with overexpressed or down-regulated YAP, we show that YAP regulates genes involved in proliferation, apoptosis, and angiogenesis. YAP activity promotes CC growth in vitro and in vivo by functionally interacting with TEAD transcription factors (TEADs). YAP activity together with TEADs prevents apoptosis induced by cytotoxic drugs, whereas YAP knockdown sensitizes CC cells to drug-induced apoptosis. We further show that the proangiogenic microfibrillar-associated protein 5 (MFAP5) is a direct transcriptional target of YAP/TEAD in CC cells and that secreted MFAP5 promotes tube formation of human microvascular endothelial cells. High YAP activity in human CC xenografts and clinical samples correlates with increased MFAP5 expression and CD31(+) vasculature. CONCLUSIONS: These findings establish YAP as a key regulator of proliferation and antiapoptotic mechanisms in CC and provide first evidence that YAP promotes angiogenesis by regulating the expression of secreted proangiogenic proteins.


Assuntos
Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos , Colangiocarcinoma/patologia , Proteínas de Ligação a DNA/fisiologia , Resistencia a Medicamentos Antineoplásicos , Neovascularização Patológica/etiologia , Proteínas Nucleares/fisiologia , Fatores de Transcrição/fisiologia , Animais , Apoptose , Neoplasias dos Ductos Biliares/irrigação sanguínea , Neoplasias dos Ductos Biliares/tratamento farmacológico , Proteínas de Ciclo Celular , Proliferação de Células , Colangiocarcinoma/irrigação sanguínea , Colangiocarcinoma/tratamento farmacológico , Proteínas Contráteis/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Glicoproteínas/genética , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Camundongos , Oncogenes
18.
Lab Invest ; 95(3): 351-62, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25418579

RESUMO

Hepatic angiosarcoma (AS) is a rare and highly aggressive tumor of endothelial origin with dismal prognosis. Studies of the molecular biology of AS and treatment options are limited as animal models are rare. We have previously shown that inducible knockout of Notch1 in mice leads to spontaneous formation of hepatic AS. The aims of this study were to: (1) establish and characterize a cell line derived from this murine AS, (2) identify molecular pathways involved in the pathogenesis and potential therapeutic targets, and (3) generate a tumor transplantation model. AS cells retained specific endothelial properties such as tube formation activity, as well as expression of CD31 and Von Willebrand factor. However, electron microscopy analysis revealed signs of dedifferentiation with loss of fenestrae and loss of contact inhibition. Microarray and pathway analysis showed substantial changes in gene expression and revealed activation of the Myc pathway. Exposing the AS cells to sorafenib reduced migration, filopodia dynamics, and cell proliferation but did not induce apoptosis. In addition, sorafenib suppressed ERK phosphorylation and expression of cyclin D2. Injection of AS cells into NOD/SCID mice resulted in formation of undifferentiated tumors, confirming the tumorigenic potential of these cells. In summary, we established and characterized a murine model of spontaneous AS formation and hepatic AS cell lines as a useful in vitro tool. Our data demonstrate antitumor activity of sorafenib in AS cells with potent inhibition of migration, filopodia formation, and cell proliferation, supporting further evaluation of sorafenib as a novel treatment strategy. In addition, AS cell transplantation provides a subcutaneous tumor model useful for in vivo preclinical drug testing.


Assuntos
Modelos Animais de Doenças , Hemangiossarcoma/patologia , Neoplasias Hepáticas/patologia , Fígado/patologia , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Células Cultivadas , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Hemangiossarcoma/genética , Hemangiossarcoma/metabolismo , Imuno-Histoquímica , Fígado/metabolismo , Fígado/ultraestrutura , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Microscopia Eletrônica , Niacinamida/análogos & derivados , Niacinamida/farmacologia , Análise de Sequência com Séries de Oligonucleotídeos , Compostos de Fenilureia/farmacologia , Receptor Notch1/deficiência , Receptor Notch1/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sorafenibe , Carga Tumoral/genética
19.
Liver Int ; 35(7): 1824-32, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25533046

RESUMO

BACKGROUND & AIMS: Differences in intrahepatic gene expression patterns may be associated with therapy response in peginterferon-treated chronic hepatitis B (CHB) patients. METHODS: We employed gene expression profiling in baseline liver biopsies of 40 CHB patients (19 HBeAg-positive; 21 HBeAg-negative) treated with peginterferon and adefovir for 48 weeks, and compared expression patterns of combined responders (HBeAg loss, HBV-DNA <2000 IU/ml, alanine aminotransferase normalization after 1 year of treatment-free follow-up) with non-responders. Genes identified by transcriptome analysis in 15 biopsies were confirmed in 25 additional biopsies by RT-qPCR. RESULTS: Transcriptome analysis demonstrated significant differences in expression of 41 genes between responders and non-responders. In responders, pathway analysis showed specific upregulation of genes related to the immune response, including chemotaxis and antigen processing and presentation. Genes upregulated in responders exhibited strongest similarity with a set of genes induced in livers of chimpanzees with acute Hepatitis B infection. Differential expression was confirmed for eight selected genes. A 2-gene subset (HLA-DPB1, SERPIN-E1) was found to predict response most accurately. Incorporation of these genes in a multivariable model with HBeAg status, HBV genotype and baseline HBsAg level correctly classified 90% of all patients, in which HLA-DPB1 and SERPIN-E1 were independent predictors of response. CONCLUSION: We identified an intrahepatic transcriptional signature associated with enhanced immune activation which predicts therapy response. These novel associations could lead to better understanding of responsiveness to peginterferon in CHB patients, and may assist in selecting possible responders to interferon-based treatment.


Assuntos
Antivirais/uso terapêutico , Perfilação da Expressão Gênica/métodos , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Fígado/efeitos dos fármacos , Análise de Sequência com Séries de Oligonucleotídeos , Polietilenoglicóis/uso terapêutico , Adenina/análogos & derivados , Adenina/uso terapêutico , Adulto , Biópsia , Distribuição de Qui-Quadrado , Quimioterapia Combinada , Feminino , Marcadores Genéticos , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/genética , Hepatite B Crônica/imunologia , Humanos , Fígado/imunologia , Fígado/metabolismo , Fígado/virologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Organofosfonatos/uso terapêutico , Seleção de Pacientes , Medicina de Precisão , Valor Preditivo dos Testes , Proteínas Recombinantes/uso terapêutico , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do Tratamento
20.
J Clin Invest ; 124(4): 1568-81, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24569457

RESUMO

The use of pegylated interferon-α (pegIFN-α) has replaced unmodified recombinant IFN-α for the treatment of chronic viral hepatitis. While the superior antiviral efficacy of pegIFN-α is generally attributed to improved pharmacokinetic properties, the pharmacodynamic effects of pegIFN-α in the liver have not been studied. Here, we analyzed pegIFN-α-induced signaling and gene regulation in paired liver biopsies obtained prior to treatment and during the first week following pegIFN-α injection in 18 patients with chronic hepatitis C. Despite sustained high concentrations of pegIFN-α in serum, the Jak/STAT pathway was activated in hepatocytes only on the first day after pegIFN-α administration. Evaluation of liver biopsies revealed that pegIFN-α induces hundreds of genes that can be classified into four clusters based on different temporal expression profiles. In all clusters, gene transcription was mainly driven by IFN-stimulated gene factor 3 (ISGF3). Compared with conventional IFN-α therapy, pegIFN-α induced a broader spectrum of gene expression, including many genes involved in cellular immunity. IFN-induced secondary transcription factors did not result in additional waves of gene expression. Our data indicate that the superior antiviral efficacy of pegIFN-α is not the result of prolonged Jak/STAT pathway activation in hepatocytes, but rather is due to induction of additional genes that are involved in cellular immune responses.


Assuntos
Interferon-alfa/farmacologia , Janus Quinases/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Polietilenoglicóis/farmacologia , Fatores de Transcrição STAT/metabolismo , Adulto , Idoso , Antivirais/farmacologia , Endopeptidases/genética , Endopeptidases/metabolismo , Feminino , Expressão Gênica/efeitos dos fármacos , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/genética , Hepatite C Crônica/metabolismo , Humanos , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/genética , Interferon alfa-2 , Fator Gênico 3 Estimulado por Interferon, Subunidade gama/genética , Fator Gênico 3 Estimulado por Interferon, Subunidade gama/metabolismo , Janus Quinases/genética , Cinética , Fígado/imunologia , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/farmacologia , Fatores de Transcrição STAT/genética , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína 1 Supressora da Sinalização de Citocina , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/genética , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Ubiquitina Tiolesterase
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