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1.
Nature ; 521(7552): 310-5, 2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25993961

RESUMO

Human evolutionary scholars have long supposed that the earliest stone tools were made by the genus Homo and that this technological development was directly linked to climate change and the spread of savannah grasslands. New fieldwork in West Turkana, Kenya, has identified evidence of much earlier hominin technological behaviour. We report the discovery of Lomekwi 3, a 3.3-million-year-old archaeological site where in situ stone artefacts occur in spatiotemporal association with Pliocene hominin fossils in a wooded palaeoenvironment. The Lomekwi 3 knappers, with a developing understanding of stone's fracture properties, combined core reduction with battering activities. Given the implications of the Lomekwi 3 assemblage for models aiming to converge environmental change, hominin evolution and technological origins, we propose for it the name 'Lomekwian', which predates the Oldowan by 700,000 years and marks a new beginning to the known archaeological record.


Assuntos
Hominidae , Comportamento de Utilização de Ferramentas , Animais , Arqueologia , Evolução Biológica , Meio Ambiente , Fósseis , História Antiga , Quênia , Paleontologia , Tecnologia/história , Fatores de Tempo
2.
J Hepatol ; 73(3): 533-539, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32151618

RESUMO

BACKGROUND & AIMS: Chronic hepatitis D (CHD) is the most severe form of chronic viral hepatitis but its role in the development of hepatocellular carcinoma (HCC) remains debated. We conducted a systematic review and meta-analysis of epidemiological studies to examine whether CHD is associated with an increased risk of HCC. METHODS: We searched PubMed, Embase and Web of Science, as well as study references and conference proceedings. We considered cohort and case-control studies allowing the calculation of effect estimates for the association between CHD (exposure) and HCC (outcome) in comparison to chronic hepatitis B. Data extraction and quality evaluation (using the Newcastle-Ottawa scale) were performed independently by 2 authors. Data were pooled using random-effects models. RESULTS: Ninety-three studies (68 case-control studies including 22,862 patients and 25 cohort studies including 75,427 patients) were included. Twelve studies accounted for confounders, in either study design or analysis (10 of which were cohorts), and 11 cohorts were prospective. The overall analysis showed a significantly increased risk of HCC in patients with CHD, despite substantial study heterogeneity (pooled odds ratio 1.28; 95% CI 1.05-1.57; I2 = 67.0%). The association was particularly strong in the absence of heterogeneity for prospective cohort studies (pooled odds ratio 2.77; 95% CI 1.79-4.28; I2 = 0%), and studies with HIV-infected patients (pooled odds ratio 7.13; 95% CI 2.83-17.92; I2 = 0%). CONCLUSIONS: We found a significantly higher risk of HCC in patients with CHD. Although further studies are needed to definitively exclude a potential bias due to antiviral treatments, our findings highlight the rationale for improved screening of hepatitis D virus infection in patients with chronic hepatitis B, and the urgent need for novel and effective antiviral therapies. LAY SUMMARY: Hepatitis D virus (HDV) is a defective pathogen requiring hepatitis B virus (HBV) to complete its life cycle. Chronic hepatitis D is the most severe form of chronic viral hepatitis, increasing the risk of cirrhosis, liver decompensation and death compared to HBV monoinfection. However, the association between HDV infection and increased risk of hepatocellular carcinoma is debated. We conducted a systematic review and found that patients with HDV infection had a significantly higher risk of developing hepatocellular carcinoma than those with HBV monoinfection.


Assuntos
Carcinoma Hepatocelular/virologia , Coinfecção/complicações , Vírus da Hepatite B , Hepatite B Crônica/complicações , Hepatite D Crônica/complicações , Vírus Delta da Hepatite , Neoplasias Hepáticas/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/diagnóstico , Estudos de Casos e Controles , Criança , Pré-Escolar , Coinfecção/virologia , Feminino , Hepatite B Crônica/virologia , Hepatite D Crônica/virologia , Humanos , Lactente , Neoplasias Hepáticas/diagnóstico , Masculino , Pessoa de Meia-Idade , Estudos Observacionais como Assunto , Estudos Prospectivos , Fatores de Risco , Adulto Jovem
3.
Antimicrob Agents Chemother ; 64(12)2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-32988820

RESUMO

Viral infections are among the main causes of death worldwide, and we lack antivirals for the majority of viruses. Heparin-like sulfated or sulfonated compounds have been known for decades for their ability to prevent infection by heparan sulfate proteoglycan (HSPG)-dependent viruses but only in a reversible way. We have previously shown that gold nanoparticles and ß-cyclodextrins coated with mercapto-undecane sulfonic acid (MUS) inhibit HSPG-dependent viruses irreversibly while retaining the low-toxicity profile of most heparin-like compounds. In this work, we show that, in stark contrast to heparin, these compounds also inhibit different strains of influenza virus and vesicular stomatitis virus (VSV), which do not bind HSPG. The antiviral action is virucidal and irreversible for influenza A virus (H1N1), while for VSV, there is a reversible inhibition of viral attachment to the cell. These results further broaden the spectrum of activity of MUS-coated gold nanoparticles and ß-cyclodextrins.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Nanopartículas Metálicas , Vírus , Antivirais/farmacologia , Ouro , Heparitina Sulfato/farmacologia
4.
Hepatology ; 69(3): 1165-1179, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30153337

RESUMO

The activating natural cytotoxicity receptor NKp30 is critical for natural killer (NK) cell function and tumor immune surveillance. The natural cytotoxicity receptor-3 (NCR3) gene is transcribed into several splice variants whose physiological relevance is still incompletely understood. In this study, we investigated the role of NKp30 and its major ligand B7 homolog 6 (B7-H6) in patients with hepatocellular carcinoma (HCC). Peripheral blood NK cell phenotype was skewed toward a defective/exhausted immune profile with decreased frequencies of cells expressing NKp30 and natural killer group 2, member D and an increased proportion of cells expressing T-cell immunoglobulin and mucin-domain containing-3. Moreover, NKp30-positive NK cells had a reduced expression of NCR3 immunostimulatory splice variants and an increased expression of the inhibitory variant in patients with advanced tumor, resulting in deficient NKp30-mediated functionality. Tumor-infiltrating lymphocytes showed a prevalent inhibitory NKp30 isoform profile, consistent with decreased NKp30-mediated function. Of note, there were significant differences in the cytokine milieu between the neoplastic and the surrounding non-neoplastic tissue, which may have further influenced NKp30 function. Exposure of NK cells to B7-H6-expressing HCC cells significantly down-modulated NKp30, that was prevented by small interfering RNA-mediated knockdown, suggesting a role for this ligand in inhibiting NKp30-mediated responses. Interestingly, B7-H6 expression was reduced in HCC tissue and simultaneously augmented as a soluble form in HCC patients, particularly those with advanced staging or larger nodule size. Conclusion: These findings provide evidence in support of a role of NKp30 and its major ligand in HCC development and evolution.


Assuntos
Carcinoma Hepatocelular/imunologia , Células Matadoras Naturais/metabolismo , Neoplasias Hepáticas/imunologia , Receptor 3 Desencadeador da Citotoxicidade Natural/imunologia , Humanos , Receptor 3 Desencadeador da Citotoxicidade Natural/biossíntese , Receptor 3 Desencadeador da Citotoxicidade Natural/deficiência , Isoformas de Proteínas , Células Tumorais Cultivadas
5.
Liver Int ; 40(3): 609-621, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31872499

RESUMO

BACKGROUND & AIMS: Our understanding of non-alcoholic fatty liver disease (NAFLD) pathogenesis is improving, but there is still limited data on the function of resident liver macrophages in this context, especially when considering their contribution in dampening liver inflammation. METHODS: Liver macrophages were studied in mouse models of prolonged diet-induced liver steatohepatitis and carbon tetrachloride-induced liver injury. We assessed liver macrophages phenotype and costimulatory/inhibitory properties upon exposure to lipopolysaccharide or interleukin 4. We did phagocytosis and antigen presentation assays to investigate liver macrophages function as scavengers and immune response initiators. Using immunofluorescence staining, we further determined, in human liver tissue of patients with simple steatosis, non-alcoholic steatohepatitis and chronic hepatitis B infection, the expression of the co-inhibitory protein CD274 (Programmed-death ligand 1) and major histocompatibility complex (MHC) class II. RESULTS: Both in humans and mice, within chronically inflamed fatty livers, liver macrophages acquired immunomodulatory properties by reducing the expression of MHC class II, and by enhancing co-inhibitory signalling. Liver macrophages circumscribed endotoxin-mediated inflammatory response by upregulating anti-inflammatory genes arginase 1 and interleukin-10. While hepatic macrophages isolated from mice with normal livers were capable of achieving endotoxin tolerance, our results indicated an impairment of this protective mechanism in the presence NASH-like parenchymal abnormalities. CONCLUSIONS: Liver macrophages can achieve endotoxin tolerance, but in the chronically inflamed fatty liver, while they acquire an immunomodulatory phenotype, liver macrophages fail to dampen immune-mediated damage. Therefore, loss of tolerogenicity induced by ongoing liver insult may be a mechanism contributing to the worsening of NAFLD.


Assuntos
Hepatite , Hepatopatia Gordurosa não Alcoólica , Animais , Humanos , Células de Kupffer , Fígado , Camundongos , Camundongos Endogâmicos C57BL
6.
PLoS Biol ; 14(3): e1002421, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27031829

RESUMO

Hepatitis C virus (HCV) is an oncogenic virus associated with the onset of hepatocellular carcinoma (HCC). The present study investigated the possible link between HCV infection and Netrin-1, a ligand for dependence receptors that sustains tumorigenesis, in particular in inflammation-associated tumors. We show that Netrin-1 expression is significantly elevated in HCV+ liver biopsies compared to hepatitis B virus (HBV+) and uninfected samples. Furthermore, Netrin-1 was upregulated in all histological stages of HCV+ hepatic lesions, from minimal liver fibrosis to cirrhosis and HCC, compared to histologically matched HCV- tissues. Both cirrhosis and HCV contributed to the induction of Netrin-1 expression, whereas anti-HCV treatment resulted in a reduction of Netrin-1 expression. In vitro, HCV increased the level and translation of Netrin-1 in a NS5A-La-related protein 1 (LARP1)-dependent fashion. Knockdown and forced expression experiments identified the receptor uncoordinated receptor-5 (UNC5A) as an antagonist of the Netrin-1 signal, though it did not affect the death of HCV-infected cells. Netrin-1 enhanced infectivity of HCV particles and promoted viral entry by increasing the activation and decreasing the recycling of the epidermal growth factor receptor (EGFR), a protein that is dysregulated in HCC. Netrin-1 and HCV are, therefore, reciprocal inducers in vitro and in patients, as seen from the increase in viral morphogenesis and viral entry, both phenomena converging toward an increase in the level of infectivity of HCV virions. This functional association involving a cancer-related virus and Netrin-1 argues for evaluating the implication of UNC5 receptor ligands in other oncogenic microbial species.


Assuntos
Receptores ErbB/metabolismo , Hepatite C/metabolismo , Fatores de Crescimento Neural/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Autoantígenos/metabolismo , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/metabolismo , Linhagem Celular , Transformação Celular Neoplásica , Hepatite C/complicações , Hepatite C/virologia , Humanos , Cirrose Hepática/metabolismo , Cirrose Hepática/virologia , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/metabolismo , Netrina-1 , Ribonucleoproteínas/metabolismo , Regulação para Cima , Proteínas não Estruturais Virais/metabolismo , Internalização do Vírus , Antígeno SS-B
7.
Liver Int ; 39(7): 1226-1236, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30938910

RESUMO

BACKGROUND & AIMS: miR-21-5p is a potent oncogenic microRNA targeting many key tumour suppressors including phosphatase and tensin homolog (PTEN). We recently identified PTEN as a key factor modulated by hepatitis C virus (HCV) to promote virion egress. In hepatocytes, expression of HCV-3a core protein was sufficient to downregulate PTEN and to trigger lipid droplet accumulation. Here, we investigated whether HCV controls PTEN expression through miR-21-5p-dependent mechanisms to trigger steatosis in hepatocytes and to promote HCV life cycle. METHODS: MiR-21-5p expression in HCV-infected patients was evaluated by transcriptome meta-analysis. HCV replication and viral particle production were investigated in Jc1-infected Huh-7 cells after miR-21-5p inhibition. PTEN expression and steatosis were assessed in HCV-3a core protein-expressing Huh-7 cells and in mouse primary hepatocytes having miR-21-5p inhibited or genetically deleted respectively. HCV-3a core-induced steatosis was assessed in vivo in Mir21a knockout mice. RESULTS: MiR-21-5p expression was significantly increased in hepatic tissues from HCV-infected patients. Infection by HCV-Jc1, or transduction with HCV-3a core, upregulated miR-21-5p expression and/or activity in Huh-7 cells. miR-21-5p inhibition decreased HCV replication and release of infectious virions by Huh-7 cells. HCV-3a core-induced PTEN downregulation and steatosis were further prevented in Huh-7 cells following miR-21-5p inhibition or in Mir21a knockout mouse primary hepatocytes. Finally, steatosis induction by AAV8-mediated HCV-3a core expression was reduced in vivo in Mir21a knockout mice. CONCLUSION: MiR-21-5p activation by HCV is a key molecular step, promoting both HCV life cycle and HCV-3a core-induced steatosis and may be among the molecular changes induced by HCV-3a to promote carcinogenesis.


Assuntos
Hepacivirus/fisiologia , Hepatócitos/metabolismo , Hepatócitos/virologia , MicroRNAs/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Proteínas do Core Viral/fisiologia , Animais , Carcinogênese , Linhagem Celular Tumoral , Regulação para Baixo , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Hepacivirus/genética , Hepatócitos/patologia , Humanos , Metabolismo dos Lipídeos , Fígado/metabolismo , Fígado/patologia , Camundongos , Camundongos Knockout , MicroRNAs/genética , Regulação para Cima , Replicação Viral
8.
Int J Mol Sci ; 20(6)2019 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-30875826

RESUMO

BACKGROUND: Interleukin-1 (IL-1)ß and IL-1 receptor antagonist (IL-1Ra) have been proposed as important mediators during chronic liver diseases. We aimed to determine whether the modulation of IL-1ß signaling with IL-1Ra impacts on liver fibrosis. METHODS: We assessed the effects of IL-1ß on human hepatic stellate cells (HSC) and in mouse models of liver fibrosis induced by bile duct ligation (BDL) or carbon tetrachloride treatment (CCl-4). RESULTS: Human HSCs treated with IL-1ß had increased IL-1ß, IL-1Ra, and MMP-9 expressions in vitro. HSCs treated with IL-1ß had reduced α-smooth muscle actin expression. These effects were all prevented by IL-1Ra treatment. In the BDL model, liver fibrosis and Kuppfer cell numbers were increased in IL-1Ra KO mice compared to wild type mice and wild type mice treated with IL-1Ra. In contrast, after CCl-4 treatment, fibrosis, HSC and Kupffer cell numbers were decreased in IL-1Ra KO mice compared to the other groups. IL-1Ra treatment provided a modest protective effect in the BDL model and was pro-fibrotic in the CCl-4 model. CONCLUSIONS: We demonstrated bivalent effects of IL-1Ra during liver fibrosis in mice. IL-1Ra was detrimental in the CCl-4 model, whereas it was protective in the BDL model. Altogether these data suggest that blocking IL-1-mediated inflammation may be beneficial only in selective liver fibrotic disease.


Assuntos
Actinas/genética , Proteína Antagonista do Receptor de Interleucina 1/genética , Interleucina-1beta/genética , Cirrose Hepática/genética , Metaloproteinase 9 da Matriz/genética , Animais , Tetracloreto de Carbono/efeitos adversos , Contagem de Células , Células Cultivadas , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Inativação de Genes , Humanos , Células de Kupffer/citologia , Células de Kupffer/efeitos dos fármacos , Células de Kupffer/imunologia , Cirrose Hepática/etiologia , Cirrose Hepática/imunologia , Masculino , Camundongos , Regulação para Cima
9.
J Gen Virol ; 97(1): 69-81, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26519381

RESUMO

There is growing evidence that virus particles also contain host cell proteins, which provide viruses with certain properties required for entry and release. A proteomic analysis performed on double-gradient-purified hepatitis C virus (HCV) from two highly viraemic patients identified the phosphatidylinositol 3,5-bisphosphate 5-phosphatase FIG4 (KIAA0274) as part of the viral particles. We validated the association using immunoelectron microscopy, immunoprecipitation and neutralization assays in vitro as well as patient-derived virus particles. RNA interference-mediated reduction of FIG4 expression decreased cholesteryl ester (CE) levels along with intra- and extracellular viral infectivity without affecting HCV RNA levels. Likewise, overexpressing FIG4 increased intracellular CE levels as well as intra- and extracellular viral infectivity without affecting viral RNA levels. Triglyceride levels and lipid droplet (LD) parameters remained unaffected. The 3,5-bisphosphate 5-phosphatase active site of FIG4 was found to strongly condition these results. Whilst FIG4 was found to localize to areas corresponding to viral assembly sites, at the immediate vicinity of LDs in calnexin-positive and HCV core-positive regions, no implication of FIG4 in the secretory pathway of the hepatocytes could be found using either FIG4-null mice, in vitro morphometry or functional assays of the ERGIC/Golgi compartments. This indicates that FIG4-dependent modulation of HCV infectivity is unrelated to alterations in the functionality of the secretory pathway. As a result of the documented implication of CE in the composition and infectivity of HCV particles, these results suggest that FIG4 binds to HCV and modulates particle formation in a CE-related manner.


Assuntos
Ésteres do Colesterol/metabolismo , Flavoproteínas/metabolismo , Hepacivirus/química , Hepacivirus/fisiologia , Interações Hospedeiro-Patógeno , Monoéster Fosfórico Hidrolases/metabolismo , Montagem de Vírus , Internalização do Vírus , Linhagem Celular , Flavoproteínas/isolamento & purificação , Hepatócitos/virologia , Humanos , Imunoprecipitação , Microscopia Imunoeletrônica , Testes de Neutralização , Monoéster Fosfórico Hidrolases/isolamento & purificação , Vírion/química
11.
J Hepatol ; 63(3): 609-21, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25872168

RESUMO

BACKGROUND & AIMS: The role of liver progenitor cell (LPC) expansion, known as a marker of disease severity, as well as the impact of macrophage activation on liver regeneration remains unclear in humans. We aimed to characterize the LPC and macrophage compartments in alcoholic hepatitis (AH), as well as gene expression patterns to identify predictors of a good prognosis in this setting. METHODS: Immunohistochemical studies for macrophages, proliferative hepatocytes, total and proliferative LPC, as well as whole liver microarray gene expression were performed on baseline liver biopsies of 58 AH patients early after admission. Abstinent cirrhotic patients were used as controls. Patients were qualified as "improvers" or "non-improvers" based on the change in MELD score three months after baseline. RESULTS: Compared to controls, AH patients demonstrated a significant expansion of macrophages, invasion of LPC and a higher number of proliferating hepatocytes and LPC. In AH patients, total LPC expansion (total Keratin7(+) cells) was associated with liver disease severity. The group of improvers (n=34) was characterized at baseline by a higher number of proliferating hepatocytes, proliferative LPC (double Keratin7(+)Ki67(+) cells) and liver macrophages as compared to non-improvers (n=24), despite similar clinical and biological variables. Upregulated genes in improvers were associated with cell cycle mitosis together with a major expression of SPINK1. CONCLUSIONS: Higher liver macrophage expansion, increased proliferative hepatocyte but also LPC number, as well as an upregulation of cell proliferation-related genes are associated with a favourable outcome. These new findings open novel therapeutic targets in AH.


Assuntos
Hepatite Alcoólica/patologia , Hepatócitos/fisiologia , Células-Tronco/fisiologia , Animais , Proteínas de Transporte/fisiologia , Proliferação de Células , Humanos , Queratina-7/análise , Macrófagos/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Prognóstico , Transcrição Gênica , Inibidor da Tripsina Pancreática de Kazal
12.
J Pediatr Gastroenterol Nutr ; 61(1): 91-3, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25643021

RESUMO

Alagille syndrome (ALGS) is a complex, multisystem disease associated with mutations in the JAG1 gene. In the liver, ALGS is characterized by paucity of intrahepatic bile ducts. Gene dosage analysis performed on a large, central regenerative nodule with preserved interlobular bile ducts of 2 unrelated ALGS patients, and on surrounding cirrhotic and ductopenic liver parenchyma, showed in both cases complete JAG1 heterozygous deletion in the regenerative nodule and the ductopenic liver, with no differences in gene dosage. Thus, JAG1 mosaicism and differential haploinsufficiency do not explain the presence of bile ducts in centrally located regenerative nodules.


Assuntos
Síndrome de Alagille/patologia , Ductos Biliares Intra-Hepáticos/patologia , Proteínas de Ligação ao Cálcio/genética , Heterozigoto , Peptídeos e Proteínas de Sinalização Intercelular/genética , Fígado/patologia , Proteínas de Membrana/genética , Mosaicismo , Mutação , Síndrome de Alagille/genética , Humanos , Proteína Jagged-1 , Neoplasias Hepáticas/genética , Masculino , Fenótipo , Proteínas Serrate-Jagged
13.
J Hepatol ; 59(3): 420-6, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23623999

RESUMO

BACKGROUND & AIMS: Hepatitis C virus (HCV) infection is dependent on lipid metabolism. Hepatocyte steatosis occurs frequently in HCV infection, but the relationship between steatosis and HCV life cycle is unclear. We showed that HCV induces steatosis via the downregulation of the phosphatase and tensin homolog deleted on chromosome 10 (PTEN). We here investigated how PTEN may affect HCV production. METHODS: The effect of overexpression or silencing of PTEN on HCV secretion was assessed in genomic-length Jc1 infected HuH7 cells. The role of PTEN protein and lipid phosphatase activities on lipid metabolism and infectious viral particle secretion was investigated using dominant-negative PTEN mutants. The importance of cholesterol metabolism for PTEN-dependent lipid droplet biogenesis and viral particle secretion was examined using statins. RESULTS: PTEN silencing in Jc1 infected HuH7 cells stimulated HCV particle secretion, while PTEN overexpression decreased virus egress. Viral secretion was also increased by overexpression of protein phosphatase-deleted (PTENY138L), but not lipid phosphatase-deleted (PTENG129E), PTEN mutant, thus indicating that the protein phosphatase activity of PTEN controls viral secretion. Similarly, PTENY138L, but not PTENG129E mutant induced the formation of large lipid droplets. PTENY138L mutant did not affect biosynthesis of triglycerides, but promoted the biosynthesis of cholesterol esters. Consistently, statins prevented the increased cholesterol ester production, large lipid droplet formation, and viral secretion in cells expressing the PTENY138L mutant. CONCLUSIONS: Downregulation of PTEN protein phosphatase activity by HCV affects cholesterol metabolism, thereby inducing the appearance of large lipid droplets and increasing virion egress.


Assuntos
Colesterol/metabolismo , Hepacivirus/fisiologia , PTEN Fosfo-Hidrolase/metabolismo , Linhagem Celular , Ésteres do Colesterol/metabolismo , Regulação para Baixo , Hepacivirus/patogenicidade , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Metabolismo dos Lipídeos , Mutação , PTEN Fosfo-Hidrolase/antagonistas & inibidores , PTEN Fosfo-Hidrolase/genética , RNA Interferente Pequeno/genética , Liberação de Vírus/genética , Liberação de Vírus/fisiologia
14.
J Gen Virol ; 94(Pt 10): 2208-2214, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23907395

RESUMO

Infectious hepatitis C virus (HCV) particle assembly starts at the surface of lipid droplets, cytoplasmic organelles responsible for neutral fat storage. We analysed the relationship between HCV and seipin, a protein involved in lipid droplet maturation. Although seipin overexpression did not affect the total mean volume occupied by lipid droplets nor the total triglyceride and cholesterol ester levels per cell, it caused an increase in the mean diameter of lipid droplets by 60 %, while decreasing their total number per cell. The latter two effects combined resulted in a 34 % reduction of the total outer surface area of lipid droplets per cell, with a proportional decrease in infectious viral particle production, probably due to a defect in particle assembly. These results suggest that the available outer surface of lipid droplets is a critical factor for HCV release, independent of the neutral lipid content of the cell.


Assuntos
Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Hepacivirus/fisiologia , Lipídeos/química , Linhagem Celular Tumoral , Subunidades gama da Proteína de Ligação ao GTP/genética , Regulação da Expressão Gênica/fisiologia , Humanos , Internalização do Vírus , Replicação Viral/fisiologia
15.
Liver Int ; 33(1): 94-103, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23164156

RESUMO

BACKGROUND: Antiviral treatment of chronic hepatitis C is not invariably successful, costly and associated with serious side-effects, and therefore should be indicated only when the chances of benefitting patients exceed the potential risks. The suppressor of cytokine signalling (SOCS) family members have been suggested to affect the rate of virological response to therapy, but the published evidence is conflicting. METHODS: We measured the intrahepatic SOCS1, SOCS3 and SOCS7 mRNA levels in 107 chronic hepatitis C patients and assessed their clinical and histological correlates with the virological response to therapy and with some factors known for affecting treatment outcome. RESULTS: By multivariate analysis, SOCS1, SOCS3 and SOCS7 mRNA levels were not associated with rapid or sustained virological response. Similarly, no association was found between the levels of any intrahepatic SOCS mRNA and those of the homeostasis model assessment of insulin resistance. Conversely, SOCS1 (OR 2.185, 95% CI 1.223-3.906, P=0.0083) and SOCS3 (OR 40.601, 95% CI 2.357-699.25, P=0.0108) mRNA level (but not SOCS7), together with age (OR 1.156, 95% CI 1.049-1.275, P=0.0036), were independently associated with cirrhosis. CONCLUSIONS: Intrahepatic SOCS1, SOCS3 and SOCS7 mRNA levels do not predict virological response to therapy in chronic hepatitis C. The association between SOCS1, SOCS3 and cirrhosis warrants further study.


Assuntos
Antivirais/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Cirrose Hepática/genética , Fígado/efeitos dos fármacos , RNA Mensageiro/análise , Proteínas Supressoras da Sinalização de Citocina/genética , Adulto , Idoso , Quimioterapia Combinada , Feminino , Hepatite C Crônica/complicações , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/genética , Humanos , Interferon-alfa/uso terapêutico , Modelos Lineares , Fígado/química , Fígado/virologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/virologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Proteínas Nucleares/genética , Razão de Chances , Estudos Retrospectivos , Ribavirina/uso terapêutico , Proteína 1 Supressora da Sinalização de Citocina , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/análise , Resultado do Tratamento , Adulto Jovem
16.
Phys Med ; 108: 102566, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36989979

RESUMO

PURPOSE: To develop SurVolT, a conversion tool able to apply volumetric changes to DICOM Computed Tomography (CT) data using daily surface (obj) data acquired with AlignRT® (VisionRT Ltd.), primarily designed and validated for breast treatments. MATERIALS AND METHODS: SurVolT proceeds in 4 steps: 1. AlignRT .obj files extraction, 2. Contour deformation where the surface data points are matched to the initial external contour on a Region Of Interest, ROImatch, on which the anatomy is supposed to be unchanged. Then, external contour substitution is performed on the ROIttt covering the treated breast area. This is validated on a female torso phantom with a tissue-equivalent bolus mimicking an edema. The Planning Treatment Volume (PTV) contour from the initial CT is also deformed according to the new external contour in the ROIttt. 3. Volumetric data estimation according to the new external contour, validated on an anthropomorphic pelvis phantom. 4. Import of new DICOM data into the Treatment Planning System (TPS). Finally, the workflow is applied on a first patient presenting an anatomical change during the treatment. RESULTS: The validation of step 2 and 3 shows a bolus thickness estimation of 5.8±1.2mm (expected 5 mm) and the non-rigid deformation of initial CT images follows the new external contour at the ROIttt bolus site while revealing negligible deformation elsewhere. CONCLUSION: This first proof of concept introducing a Surface Guided Radiotherapy (SGRT) tool allowing daily surface data to volume conversion is a fundamental step toward SGRT-based adaptive radiotherapy.


Assuntos
Braquiterapia , Radioterapia Guiada por Imagem , Humanos , Feminino , Tomografia Computadorizada por Raios X/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos , Dosagem Radioterapêutica
17.
JHEP Rep ; 5(3): 100652, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36704052

RESUMO

Background & Aims: Chronic hepatitis delta is the most severe form of chronic viral hepatitis and is associated with faster progression towards cirrhosis, liver decompensation, and hepatocellular carcinoma. Hepatitis delta virus (HDV)'s tight dependency on hepatitis B virus and the host cell machinery for its life cycle limits the development of direct-acting antivirals. Thus, we aimed to identify compounds that could block HDV replication by targeting its antigenomic ribozyme. Methods: We generated stable Huh7 human hepatoma cells expressing a reporter gene (Gaussia luciferase) either downstream (Gluc-2xRz) or upstream (2xRz-Gluc) of two HDV antigenomic ribozyme sequences. We performed high-throughput screening of three small molecule libraries. The secreted luciferase was measured as a readout of ribozyme inhibition upon addition of the molecules. Each plate was considered valid when the Z factor was >0.4. Specificity and toxicity evaluations were performed for the hits with a Z-score >5 and half-maximal inhibitory concentration was calculated by performing a dose-response experiment. Results: A dose-dependent induction of luciferase expression was detected in Gluc-2xRz-transfected cells incubated with the antisense morpholino, suggesting that the catalytic activity of the ribozyme cloned downstream of the reporter gene was efficiently inhibited. Among the 6,644 compounds screened, we identified four compounds that showed a specific inhibitory effect on the HDV antigenomic ribozyme in Gluc-2xRz cells, i.e. three histone deacetylase inhibitors and the purine analogue 8-azaguanine. The latter also significantly decreased HDV replication (by 40%) in differentiated HepaRG cells six days post infection. Conclusion: Using a novel cell culture model, we identified four small molecules active against the antigenomic HDV ribozyme. These results may provide insights into the structural requirements of molecules designed for the potent and specific inhibition of HDV replication. Impact and implications: Chronic hepatitis delta is the most severe form of chronic viral hepatitis and is associated with faster progression towards cirrhosis, liver decompensation, and the development of hepatocellular carcinoma. Despite the current development of several new compounds, there is still a need for efficient antiviral treatments specifically targeting hepatitis delta virus (HDV). This work describes a novel cell culture model that allows for the high-throughput screening of compounds able to inhibit HDV ribozymes. We identified four small molecules active against the antigenomic HDV ribozyme (the ribozyme involved in the early step of HDV replication), with the strongest activity shown by 8-azaguanine, a purine analogue. Our data may provide insights into the structural requirements of molecules designed to inhibit HDV.

18.
Sci Rep ; 13(1): 6767, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37185283

RESUMO

Chronic hepatitis C (CHC) is associated with the development of metabolic disorders, including both hepatic and extra-hepatic insulin resistance (IR). Here, we aimed at identifying liver-derived factor(s) potentially inducing peripheral IR and uncovering the mechanisms whereby HCV can regulate the action of these factors. We found ANGPTL4 (Angiopoietin Like 4) mRNA expression levels to positively correlate with HCV RNA (r = 0.46, p < 0.03) and HOMA-IR score (r = 0.51, p = 0.01) in liver biopsies of lean CHC patients. Moreover, we observed an upregulation of ANGPTL4 expression in two models recapitulating HCV-induced peripheral IR, i.e. mice expressing core protein of HCV genotype 3a (HCV-3a core) in hepatocytes and hepatoma cells transduced with HCV-3a core. Treatment of differentiated myocytes with recombinant ANGPTL4 reduced insulin-induced Akt-Ser473 phosphorylation. In contrast, conditioned medium from ANGPTL4-KO hepatoma cells prevented muscle cells from HCV-3a core induced IR. Treatment of HCV-3a core expressing HepG2 cells with PPARγ antagonist resulted in a decrease of HCV-core induced ANGPTL4 upregulation. Together, our data identified ANGPTL4 as a potential driver of HCV-induced IR and may provide working hypotheses aimed at understanding the pathogenesis of IR in the setting of other chronic liver disorders.


Assuntos
Carcinoma Hepatocelular , Hepatite C Crônica , Resistência à Insulina , Neoplasias Hepáticas , Animais , Camundongos , Carcinoma Hepatocelular/genética , Genótipo , Hepacivirus/genética , Hepatite C Crônica/patologia , Insulina/genética , Resistência à Insulina/fisiologia , Neoplasias Hepáticas/genética
19.
Front Microbiol ; 14: 1106945, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36937308

RESUMO

Introduction: Rhinovirus (RV) infections constitute one of the main triggers of asthma exacerbations and an important burden in pediatric yard. However, the mechanisms underlying this association remain poorly understood. Methods: In the present study, we compared infections of in vitro reconstituted airway epithelia originating from asthmatic versus healthy donors with representative strains of RV-A major group and minor groups, RV-C, RV-B, and the respiratory enterovirus EV-D68. Results: We found that viral replication was higher in tissues derived from asthmatic donors for all tested viruses. Viral receptor expression was comparable in non-infected tissues from both groups. After infection, ICAM1 and LDLR were upregulated, while CDHR3 was downregulated. Overall, these variations were related to viral replication levels. The presence of the CDHR3 asthma susceptibility allele (rs6967330) was not associated with increased RV-C replication. Regarding the tissue response, a significantly higher interferon (IFN) induction was demonstrated in infected tissues derived from asthmatic donors, which excludes a defect in IFN-response. Unbiased transcriptomic comparison of asthmatic versus control tissues revealed significant modifications, such as alterations of cilia structure and motility, in both infected and non-infected tissues. These observations were supported by a reduced mucociliary clearance and increased mucus secretion in non-infected tissues from asthmatic donors. Discussion: Altogether, we demonstrated an increased permissiveness and susceptibility to RV and respiratory EV infections in HAE derived from asthmatic patients, which was associated with a global alteration in epithelial cell functions. These results unveil the mechanisms underlying the pathogenesis of asthma exacerbation and suggest interesting therapeutic targets.

20.
JCO Precis Oncol ; 7: e2200555, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37364234

RESUMO

PURPOSE: The efficiency of the Myriad Homologous Recombination Deficiency (HRD) test to guide the use of poly (ADP-ribose) polymerase (PARP) inhibitors has been demonstrated in several phase III trials. However, a need exists for alternative clinically validated tests. METHODS: A novel biomarker for HRD was developed using The Cancer Genome Atlas database and, as part of the ENGOT HRD European Initiative, applied to 469 samples from the PAOLA-1/ENGOT-ov25 trial. Results were compared with the Myriad myChoice Genomic Instability Score (GIS) with respect to the progression-free survival in the olaparib + bevacizumab and placebo + bevacizumab arms. RESULTS: Analysis of the TCGA cohort revealed that a normalization of the number of large-scale state transitions by the number of whole-genome doubling events allows a better separation and classification of HRD samples than the GIS. Analysis of the PAOLA-1 samples, using the Geneva test (OncoScan + nLST), yielded a lower failure rate (27 of 469 v 59 of 469) and a hazard ratio of 0.40 (95% CI, 0.28 to 0.57) compared with 0.37 for Myriad myChoice (BRCAm or GIS+) in the nLST-positive samples. In patients with BRCAwt, the Geneva test identified a novel subpopulation of patients, with a favorable 1-year PFS (85%) but a poor 2-year PFS (30%) on olaparib + bevacizumab treatment. CONCLUSION: The proposed test efficiently separates HRD-positive from HRD-negative patients, predicts response to PARP inhibition, and can be easily deployed in a clinical laboratory for routine practice. The performance is similar to the available commercial test, but its lower failure rate allows an increase in the number of patients who will receive a conclusive laboratory result.


Assuntos
Carcinoma , Neoplasias Ovarianas , Feminino , Humanos , Bevacizumab/farmacologia , Bevacizumab/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Carcinoma Epitelial do Ovário/tratamento farmacológico , Biomarcadores , Poli(ADP-Ribose) Polimerases/genética , Poli(ADP-Ribose) Polimerases/uso terapêutico , Recombinação Homóloga
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