Cultivation-Independent Methods Reveal Differences among Bacterial Gut Microbiota in Triatomine Vectors of Chagas Disease

Chagas disease is one of the most important endemic diseases of South and Central America. Its causative agent is the protozoan Trypanosoma cruzi, which is transmitted to humans by blood-feeding insects known as triatomine bugs. These vectors mainly belong to Rhodnius, Triatoma and Panstrongylus genera of Reduviidae. The bacterial communities in the guts of these vectors may have important effects on the biology of T. cruzi. For this reason, we analyzed the bacterial diversity hosted in the gut of different species of triatomines using cultivation-independent methods. Among Rhodnius sp., we observed similar bacterial communities from specimens obtained from insectaries or sylvatic conditions. Endosymbionts of the Arsenophonus genus were preferentially associated with insects of the Panstrongylus and Triatoma genera, whereas the bacterial genus Serratia and Candidatus Rohrkolberia were typical of Rhodnius and Dipetalogaster, respectively. The diversity of the microbiota tended to be the largest in the Triatoma genus, with species of both Arsenophonus and Serratia being detected in T. infestans

Coopération oncogénique et effets métaboliques de FGF19 dans le carcinome hépatocellulaire

Hepatocellular carcinoma (HCC) is the most common primary hepatic malignancy and ranks 6th and 3rd in terms of frequency and cancer mortality, respectively. Overexpression of FGF19 is a common event in human HCC and compounds targeting FGF19 or its receptor tyrosine kinase in the liver (Fibroblast Growth Factor Receptor 4 FGFR4) are being investigated. Studies in mice have shown that long term exposure to high levels of FGF19 causes hepatic tumorigenesis. In addition, FGF19 exerts numerous metabolic effects resulting in protection against insulin resistance. Thus, FGF19 analogs are under evaluation for treatment of metabolic diseases, such as non-alcoholic steatohepatitis (NASH). The aim of our study was to further characterize the oncogenic and metabolic effects of FGF19 in an immunocompetent mouse model.Using the technique of hydrodynamic gene transfer, we obtained C57Bl6/J mice with persistent hepatic expression of FGF19, displaying supra-physiological circulating concentrations of the hormone, associated with inhibition of the bile acid synthesis pathway. We discovered that these mice display a phenotype of diabetes insipidus, characterized by polydipsia and urine dilution persisting over time. This effect resembles that already described for FGF21, a molecule belonging to the same family as FGF19. However, the effect of FGF19 is independent of FGF21 and is also present when a tumor overexpressing FGF19 is injected orthotopically.Furthermore, FGF19 expression, alone or with simultaneous invalidation of p53 by CRISPR-Cas9 technology, gives rise to well-differentiated HCC after 9-12 months. The combination of FGF19 with C-Myc overexpression, with or without the invalidation of p53, induces the development of large, moderately differentiated tumors appearing after only 2-3 weeks. Comparison with tumorigenesis triggered by C-Myc alone or by C-Myc/ CRISPR-p53, reveals oncogenic cooperation between Myc and FGF19, resulting in a very significant acceleration of oncogenesis by FGF19. Transcriptomic and histological analyses of these tumors show that FGF19 stimulates neoangiogenesis. Finally, in a NASH-inducing diet model, tumor expression of FGF19 exerts a paradoxical effect: while accelerating tumor growth, it is accompanied by histological improvement of NASH.Le carcinome hépatocellulaire (CHC) est la tumeur maligne primitive hépatique la plus fréquente et se situe au 6e et 3ème rang en termes de fréquence et de mortalité liées au cancer, respectivement. La surexpression de FGF19 est un évènement fréquent dans les CHC humains et des molécules ciblant FGF19 ou son récepteur tyrosine kinase dans le foie (Fibroblast Growth Factor Receptor 4 FGFR4) sont en cours d’étude. Chez la souris l’exposition à des concentrations élevées de FGF19 au long cours provoque une tumorigénèse hépatique. Par ailleurs, FGF19 exerce de nombreux effets métaboliques ayant pour conséquence une protection contre l’insulinorésistance. Ainsi, des molécules analogues à FGF19 sont également en cours d’étude pour traitement de maladies métaboliques, comme la stéatohépatite non alcoolique (ou NASH pour Non alcoholic steatohepatitis). Dans ce contexte, notre projet avait pour but de mieux caractériser les effets oncogéniques et métaboliques de FGF19 dans un modèle de souris immunocompétentes.En utilisant la technique de transfection hydrodynamique des hépatocytes, nous avons obtenu des souris C57Bl6/J ayant une expression de FGF19 persistante, avec des concentrations circulantes supra-physiologiques, associée à l’inhibition de la voie de synthèse des acides biliaires. Nous avons découvert chez ces souris un phénotype de diabète insipide, caractérisé par une polydipsie et une dilution des urines persistant dans le temps. Cet effet est similaire à celui qui a déjà été décrit pour FGF21, une molécule appartenant à la même famille que FGF19. Cependant, l’effet de FGF19 est indépendant de FGF21 et est retrouvé également lorsqu’une tumeur surexprimant FGF19 est injectée par voie orthotopique.Par ailleurs, l’expression de FGF19, seule ou avec l’invalidation simultanée de p53 par la technique de CRISPR-Cas9, donne des CHC bien différenciés après 9-12 mois. La combinaison FGF19 avec une surexpression de C-Myc, avec ou sans l’invalidation de p53, induit le développement de volumineuses tumeurs moyennement différenciées apparaissant après 2-3 semaines seulement. La comparaison avec la tumorigenèse déclenchée par C-Myc seul ou par C-Myc/ CRISPR-p53, fait apparaître une coopération entre Myc et FGF19 donnant lieu à l’accélération très significative de l’oncogenèse par FGF19. L’analyse transcriptomique et histologique de ces tumeurs met en évidence une stimulation de la néoangiogénèse par FGF19. Enfin, dans un modèle de régime pourvoyeur de NASH, l’expression tumorale de FGF19 exerce un effet paradoxal : tout en accélérant la croissance tumorale, elle s’accompagne d’une amélioration histologique de la NASH

Oncogenic Cooperation and Metabolic Effects of FGF19 in Hepatocellular Carcinoma

Le carcinome hépatocellulaire (CHC) est la tumeur maligne primitive hépatique la plus fréquente et se situe au 6e et 3ème rang en termes de fréquence et de mortalité liées au cancer, respectivement. La surexpression de FGF19 est un évènement fréquent dans les CHC humains et des molécules ciblant FGF19 ou son récepteur tyrosine kinase dans le foie (Fibroblast Growth Factor Receptor 4 FGFR4) sont en cours d’étude. Chez la souris l’exposition à des concentrations élevées de FGF19 au long cours provoque une tumorigénèse hépatique. Par ailleurs, FGF19 exerce de nombreux effets métaboliques ayant pour conséquence une protection contre l’insulinorésistance. Ainsi, des molécules analogues à FGF19 sont également en cours d’étude pour traitement de maladies métaboliques, comme la stéatohépatite non alcoolique (ou NASH pour Non alcoholic steatohepatitis). Dans ce contexte, notre projet avait pour but de mieux caractériser les effets oncogéniques et métaboliques de FGF19 dans un modèle de souris immunocompétentes.En utilisant la technique de transfection hydrodynamique des hépatocytes, nous avons obtenu des souris C57Bl6/J ayant une expression de FGF19 persistante, avec des concentrations circulantes supra-physiologiques, associée à l’inhibition de la voie de synthèse des acides biliaires. Nous avons découvert chez ces souris un phénotype de diabète insipide, caractérisé par une polydipsie et une dilution des urines persistant dans le temps. Cet effet est similaire à celui qui a déjà été décrit pour FGF21, une molécule appartenant à la même famille que FGF19. Cependant, l’effet de FGF19 est indépendant de FGF21 et est retrouvé également lorsqu’une tumeur surexprimant FGF19 est injectée par voie orthotopique.Par ailleurs, l’expression de FGF19, seule ou avec l’invalidation simultanée de p53 par la technique de CRISPR-Cas9, donne des CHC bien différenciés après 9-12 mois. La combinaison FGF19 avec une surexpression de C-Myc, avec ou sans l’invalidation de p53, induit le développement de volumineuses tumeurs moyennement différenciées apparaissant après 2-3 semaines seulement. La comparaison avec la tumorigenèse déclenchée par C-Myc seul ou par C-Myc/ CRISPR-p53, fait apparaître une coopération entre Myc et FGF19 donnant lieu à l’accélération très significative de l’oncogenèse par FGF19. L’analyse transcriptomique et histologique de ces tumeurs met en évidence une stimulation de la néoangiogénèse par FGF19. Enfin, dans un modèle de régime pourvoyeur de NASH, l’expression tumorale de FGF19 exerce un effet paradoxal : tout en accélérant la croissance tumorale, elle s’accompagne d’une amélioration histologique de la NASH.Hepatocellular carcinoma (HCC) is the most common primary hepatic malignancy and ranks 6th and 3rd in terms of frequency and cancer mortality, respectively. Overexpression of FGF19 is a common event in human HCC and compounds targeting FGF19 or its receptor tyrosine kinase in the liver (Fibroblast Growth Factor Receptor 4 FGFR4) are being investigated. Studies in mice have shown that long term exposure to high levels of FGF19 causes hepatic tumorigenesis. In addition, FGF19 exerts numerous metabolic effects resulting in protection against insulin resistance. Thus, FGF19 analogs are under evaluation for treatment of metabolic diseases, such as non-alcoholic steatohepatitis (NASH). The aim of our study was to further characterize the oncogenic and metabolic effects of FGF19 in an immunocompetent mouse model.Using the technique of hydrodynamic gene transfer, we obtained C57Bl6/J mice with persistent hepatic expression of FGF19, displaying supra-physiological circulating concentrations of the hormone, associated with inhibition of the bile acid synthesis pathway. We discovered that these mice display a phenotype of diabetes insipidus, characterized by polydipsia and urine dilution persisting over time. This effect resembles that already described for FGF21, a molecule belonging to the same family as FGF19. However, the effect of FGF19 is independent of FGF21 and is also present when a tumor overexpressing FGF19 is injected orthotopically.Furthermore, FGF19 expression, alone or with simultaneous invalidation of p53 by CRISPR-Cas9 technology, gives rise to well-differentiated HCC after 9-12 months. The combination of FGF19 with C-Myc overexpression, with or without the invalidation of p53, induces the development of large, moderately differentiated tumors appearing after only 2-3 weeks. Comparison with tumorigenesis triggered by C-Myc alone or by C-Myc/ CRISPR-p53, reveals oncogenic cooperation between Myc and FGF19, resulting in a very significant acceleration of oncogenesis by FGF19. Transcriptomic and histological analyses of these tumors show that FGF19 stimulates neoangiogenesis. Finally, in a NASH-inducing diet model, tumor expression of FGF19 exerts a paradoxical effect: while accelerating tumor growth, it is accompanied by histological improvement of NASH

Establishing a blueprint for successful liver transplantation for alcohol-related cirrhosis: the importance of a multidisciplinary team

International audienc

Liver Biopsy in Chronic Liver Diseases: Is There a Favorable Benefit: Risk Balance?

International audienceLiver biopsy is still useful in selected clinical situations in which it is the only tool to obtain information necessary for the diagnosis, the prognosis, and the decision for treatment. Main examples are viral hepatitis with confounding co-morbidities, non alcoholic fatty liver disease, and autoimmune liver diseases

The Influence of Alcohol Use on Outcomes in Patients Transplanted for Non-alcoholic Liver Disease

International audienceAlcohol relapse after liver transplantation (LT) for alcoholic liver disease (ALD) is a common event that has been extensively studied. In contrast, alcohol consumption has usually been neglected in patients transplanted for other liver diseases. First off, patients can be mislabeled as 'non-ALD' when they suffer from another chronic liver disease. Then, alcohol consumption is not systematically tracked after LT in recipients having a primary indication other than ALD, although there are increasing data incriminating alcohol as responsible for graft damage and impaired survival. This review discusses the potential consequences of alcohol after liver transplantation, focusing on patients transplanted for non-alcoholic liver disease, as well as the legitimate role of an addiction specialist, before and after LT

Alcohol use and smoking after liver transplantation; complications and prevention

International audienceThe last thirty years have been very prosperous in the field of liver transplantation (LT), with great advances in organ conservation, surgical techniques, peri-operative management and long-term immunosuppression, resulting in improved patient and graft survival rates as well as quality of life. However, substance addiction after LT, namely alcohol and tobacco, results in short term morbidity together with medium and long-term mortality. The main consequences can be vascular (increased risk of hepatic artery thrombosis in smokers), hepatic (recurrent alcoholic cirrhosis in alcohol relapsers) and oncological (increased risk of malignancy in patients consuming tobacco and/or alcohol after LT). This issue has thus drawn attention in the field of LT research. The management of these two at-risk behaviors addictions need the implication of hepatologists and addiction specialists, before and after LT. This review will summarize our current knowledge in alcohol use and cigarette smoking in the setting of LT, give practical tools for identification of high risk patients and treatment options

Solid, non-skin, post-liver transplant tumors: Key role of lifestyle and immunosuppression management

International audienceLiver transplantation has been the treatment of choice for end-stage liver disease since 1983. Cancer has emerged as a major long-term cause of death for liver transplant recipients. Many retrospective studies that have explored standardized incidence ratio have reported increased rates of solid organ cancers post-liver transplantation; some have also studied risk factors. Liver transplantation results in a two to five-fold mean increase in the rate of solid organ cancers. Risk of head and neck, lung, esophageal, cervical cancers and Kaposi's sarcoma is high, but risk of colorectal cancer is not clearly demonstrated. There appears to be no excess risk of developing breast or prostate cancer. Environmental risk factors such as viral infection and tobacco consumption, and personal risk factors such as obesity play a key role, but recent data also implicate the role of calcineurin inhibitors, whose cumulative and dose-dependent effects on cell metabolism might play a direct role in oncogenesis. In this paper, we review the results of studies assessing the incidence of non-skin solid tumors in order to understand the mechanisms underlying solid cancers in post-liver transplant patients and, ultimately, discuss how to prevent these cancers. Immunosuppressive protocol changes, including a calcineurin inhibitor-free regimen, combined with dietary guidelines and smoking cessation, are theoretically the best preventive measures

Follow-Up of Alcohol Consumption After Liver Transplantation: Interest of an Addiction Team?

International audienceBACKGROUND:Alcohol relapses after liver transplantation (LT) constitute a critical issue. Because there is no widely accepted definition of LT, its prevalence varies from 7 to 95% across studies. Only a severe relapse, the frequency of which is estimated to be 11 to 26%, decreases life expectancy after 5 years of LT and requires specific care. To improve the early identification of alcohol consumption among transplanted patients, liver transplant teams may be helped by input from an addiction team. Nevertheless, added benefit of involvement by addiction specialists in treating posttransplant patients has not been demonstrated. Thus, the aim of this study was to compare the evaluation of the alcohol consumption after LT performed routinely during the transplant consultation or obtained from a specific addiction consultation.METHODS:This was a prospective single-site study. Patients were seen consecutively by their hepatologist and by an addiction specialist, and they completed the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C). Thus, the patient's alcohol status was assessed using 3 different sources of information: the hepatologist's interview, the AUDIT-C score, and the addiction specialist visit.RESULTS:One hundred forty-one patients were consecutively evaluated. Alcohol consumption was identified by the hepatologist in 31 patients (21.9%), in 52 (36.8%) using the AUDIT-C questionnaire, and in 58 (41.1%) by the addiction specialist. The 31 patients concerned reported an average of 6.5 alcohol units/wk to the transplant physician, a number which was significantly greater (p = 0.001) by 8.6 units/wk when they were interviewed by the addiction specialist.CONCLUSIONS:This study highlights the clinical utility of a systematic addiction consultation among liver transplant patients, irrespective of the reason for transplantation