Search

ObjectiveWhile appendectomy may reduce colorectal inflammation in patients with ulcerative colitis (UC), appendectomy has been suggested to be associated with an increased risk of colitis-associated cancer (CAC). The aim of this study was to explore the mechanism underlying the appendectomy-associated increased risk of CAC.DesignFive-week-old male BALB/c mice underwent appendectomy, appendicitis induction or sham laparotomy. They were then exposed to azoxymethane/dextran sodium sulfate (AOM/DSS) to induce CAC. Mice were sacrificed 12 weeks later, and colons were taken for pathological analysis and immunohistochemistry (CD3 and CD8 staining). Human colonic tumors from 21 UC patients who underwent surgical resection for CAC were immunophenotyped and stratified according to the appendectomy status.ResultsWhile appendectomy significantly reduced colitis severity and increased CAC number, appendicitis induction without appendectomy led to opposite results. Intra-tumor CD3+ and CD8+ T-cell densities were lower after appendectomy and higher after appendicitis induction compared to the sham laparotomy group. Blocking lymphocyte trafficking to the colon with the anti-α4β7 integrin antibody or a sphingosine-1-phosphate receptor agonist suppressed the inducing effect of the appendectomy on tumors’ number and on CD3+/CD8+ intra-tumoral density. CD8+ or CD3+ T cells isolated from inflammatory neo-appendix and intravenously injected into AOM/DSS-treated recipient mice increased CD3+/CD8+ T-cell tumor infiltration and decreased tumor number. In UC patients with a history of appendectomy, intra-tumor CD3+ and CD8+ T-cell densities were decreased compared to UC patients without history of appendectomy.ConclusionsIn UC, appendectomy could suppress a major site of T-cell priming resulting in a less efficient CAC immunosurveillance.Significance of this studyWhat is already known on this subject?The protective effect of preemptive appendectomy is currently investigated as a therapy for refractory ulcerative colitis (UC), with encouraging results.An increased risk of developing colitis-associated cancer (CAC) caused by this promising treatment has been identified.Since it is commonly accepted that CAC is related to colitis severity and extent, this finding is counterintuitive and the mechanisms of this paradoxical effect remain unknown.What are the new findings?In a mouse model of CAC, less extended colitis associated with an increased number of tumors was observed. Intra-tumor T-cell infiltration was significantly reduced after appendectomy. Blocking lymphocyte trafficking to the colon with current or experimental UC treatments mimicked the appendectomy-associated phenotype whereas neo-appendicitis or appendix-primed T-cell injection in recipient mice increased intra-tumor T-cell infiltration and strengthened protection against CAC.In UC patients with CAC, appendectomy was associated with a decreased intra-tumor T-cell infiltration.These findings suggest that, in UC, appendectomy could suppress a major site of T-cell priming in the colon, resulting in a reduced CAC immunosurveillance.How might it impact on clinical practice in the foreseeable future?This work emphasizes the fact that precautions will be necessary if appendectomy becomes an accepted therapeutic option for the treatment of refractory UC.Innovative cell-based therapies and immunotherapies, such as the administration of stimulated autologous appendicular T cells in patients with CAC are promising options.

International audience; Background and Aims: HDV, a satellite of HBV, is responsible for the most severe form of human viral hepatitis, for which curative therapy is still awaited. Both HBV and HDV use the hepatic transporter of bile acids (ie, Na+-taurocholate cotransporting polypeptide) to enter hepatocytes. We have previously shown that ligands of the farnesoid-X-receptor alpha (FXR), a master regulator of bile acids metabolism, inhibit HBV replication. Here we asked whether FXR ligands can also control HDV infection.Approach and Results: In vitro HDV monoinfections or HDV/HBV coinfections and superinfections were performed in differentiated HepaRG cells (dHepaRG) and primary human hepatocytes. Following treatment with FXR ligands, HDV RNAs and antigens were analyzed by RT-qPCR, northern blot, immunofluorescence, and western blot. Virus secretion was studied by RNA quantification in supernatants, and the infectivity of secreted HDV particles was measured by reinfection of naive HuH7.5-Na+-taurocholate cotransporting polypeptide cells. In HDV/HBV superinfection models, a 10-day treatment with FXR ligand GW4064 decreased intracellular HDV RNAs by 60% and 40% in dHepaRG cells and primary human hepatocytes, respectively. Both HDV genomic and antigenomic RNAs were affected by treatment, which also reduced the amount of intracellular delta antigen. This antiviral effect was also observed in HDV monoinfected dHepaRG cells, abolished by FXR loss of function, and reproduced with other FXR ligands. In HBV/HDV coinfected dHepaRG cells, HDV secretion was decreased by 60% and virion-specific infectivity by >95%.Conclusions: FXR ligands both inhibit directly (ie, independently of anti-HBV activity) and indirectly (ie, dependently of anti-HBV activity) the replication, secretion, and infectivity of HDV. The overall anti-HDV activity was superior to that obtained with interferon-α, highlighting the therapeutic potential of FXR ligands in HDV-infected patients.

Background and aims: Autoimmune hepatitis (AIH) is a rare indication (

International audience; Background Bacteriobilia may increase the rate of deep infectious complications (DIC) after pancreaticoduodenectomy. To better adjust prophylactic and empirical antibacterial treatment, we aimed to characterize bacteriobilia in patients with preoperative endoprosthesis, and its association with postoperative DIC. Methods All patients who underwent pancreaticoduodenectomy in our center between 2010 and 2019 were included. The association between microbiological findings from bile samples, and postoperative DIC was analyzed, and we compared microbiology data between 2010-2014 and 2015-2019 periods. Results We enrolled 578 patients (median age 67 years [59-72], 58.7% males), of whom 220 (38.1%) had preoperative biliary endoprosthesis, with 197 (89.5%) positive preoperative bile samples pathogens were Enterobacterales, enterococci, and Candida albicans. The incidence of DIC was similar in patients with or without endoprosthesis (20.4% vs 17.8%, P = .352). Bacterial isolates collected during 2015-2019 were more resistant to cefotaxime than those recovered from 2010-2014 (45.5% vs 25.5%, P = .009). The only independent risk factor for DIC in patients with endoprosthesis was cefotaxime resistance in bile (hazard ratio 3.027 [1.115-8.216], P = .03). Conclusions The incidence of DIC is high after pancreaticoduodenectomy, with or without endoprosthesis, despite routine postoperative treatment. Cefotaxime resistance, the only independent predictor of DIC in patients with endoprosthesis, has increased over time. Hence, cefotaxime may no longer be an appropriate empirical treatment.

International audience; Background and aims: A single hepatitis B virus (HBV) particle is sufficient to establish chronic infection of the liver after intravenous injection, suggesting that the virus targets hepatocytes via a highly efficient transport pathway. We therefore investigated whether HBV utilizes a physiological liver-directed pathway that supports specific host-cell targeting in vivo.Methods: We established an ex vivo system of perfused human liver tissue that recapitulates the liver physiology to investigate HBV liver targeting. This model allowed us to investigate virus-host cell interactions in a cellular microenvironment mimicking the in vivo situation. Results: HBV was rapidly sequestered by liver macrophages within one hour after a virus pulse, but was detected in hepatocytes only after 16 hours. We found that HBV associates with lipoproteins. Electron- and immunofluorescence microscopy corroborated a co-localization in recycling endosomes within peripheral and liver macrophages. Importantly, recycling endosomes accumulated HBV and cholesterol, followed by transport of HBV back to the cell surface along the cholesterol efflux pathway. To reach hepatocytes as final target cells, HBV was able to utilise the hepatocyte-directed cholesterol transport machinery of macrophages.Conclusions: Our results propose that HBV by binding to liver targeted lipoproteins and utilizing the reverse cholesterol transport pathway of macrophages hijacks the physiological lipid transport pathways to the liver to most efficiently reach its target organ. This may involve trans-infection of liver macrophages and result in deposition of HBV in the perisinusoidal space from where HBV can bind its receptor on hepatocytes

Background & aims: Liver transplantation (LT) is the only available treatment for end-stage non-alcoholic fatty liver disease (NAFLD) (related decompensated cirrhosis and/or hepatocellular carcinoma). The aim of our study was to evaluate the risk of disease recurrence after LT and the factors influencing it.Method: This retrospective multicenter study included adults transplanted for NAFLD cirrhosis between 2000 and 2019 in 20 participating French-speaking centers. Disease recurrence (steatosis, steatohepatitis and fibrosis) was diagnosed from liver graft biopsies.Results: We analyzed 150 patients with at least one graft liver biopsy available ≥6 months after transplantation, among 361 patients transplanted for NAFLD. The median (IQR) age at LT was 61.3 (54.4-64.6) years. The median follow-up after LT was 4.7 (2.8-8.1) years. The cumulative recurrence rates of steatosis and steatohepatitis at 5 years were 80.0% and 60.3%, respectively. Significant risk factors for steatohepatitis recurrence in multivariate analysis were recipient age at LT

International audience; BACKGROUND: Whether healthcare workers with inflammatory bowel disease (IBD) are at increased risk of Novel coronavirus disease (COVID-19) due to occupational exposure is unknown. AIM: To assess the risk of COVID-19 in healthcare workers with IBD. METHODS: A case control study enrolled 326 healthcare workers with IBD from 17 GETAID centres and matched non-healthcare workers with IBD controls (1:1) for gender, age, disease subtype and year of diagnosis. The study period was year 2020 during the COVID-19 outbreak. RESULTS: In total, 59 COVID-19 were recorded among cases (n = 32) and controls (n = 27), including 2 severe COVID-19 (requiring hospitalization, mechanic ventilation) but no death. No difference was observed between healthcare workers and controls regarding the overall incidence rates of COVID-19 4.9 ± 2.2 vs. 3.8 ± 1.9 per 100 patient-semesters, P = 0.34) and the overall incidence rates of severe COVID-19 (0.6 ± 7.8 vs. 0.3 ± 5.5 per 100 patient-semesters, P = 0.42). In multivariate analysis in the entire study population, COVID-19 was associated with patients with body mass index > 30 kg/m(2) (HR = 2.48, 95%CI [1.13-5.44], P = 0.02). CONCLUSION: Healthcare workers with IBD do not have an increased risk of COVID-19 compared with other patients with IBD.

International audience; Background & Aims: Over time, chronic HCV infection can lead to hepatocellular carcinoma (HCC), a process that involves changes to the liver extracellular matrix (ECM). However, the exact mechanisms by which HCV induces HCC remain unclear. Therefore, we sought to investigate the impact of HCV on the liver ECM, with a focus on heparanase-1 (HPSE).Methods: HPSE expression was assessed by quantitative reverse-transcription PCR, immunoblotting and immunofluorescence in liver biopsies infected or not with HCV, and in 10-day-infected hepatoma Huh7.5 cells. Cell lines deficient for or overexpressing HPSE were established to study its role during infection.Results: HCV propagation led to significant HPSE induction, in vivo and in vitro. HPSE enhanced infection when exogenously expressed or supplemented as a recombinant protein. Conversely, when HPSE expression was downregulated or its activity blocked, HCV infection dropped, suggesting a role of HPSE in the HCV life cycle. We further studied the underlying mechanisms of such observations and found that HPSE favored HCV release by enhancing CD63 synthesis and exosome secretion, but not by stimulating HCV entry or genome replication. We also showed that virus-induced oxidative stress was involved in HPSE induction, most likely through NF-κB activation.Conclusions: We report for the first time that HCV infection is favored by HPSE, and upregulates HPSE expression and secretion, which may result in pathogenic alterations of the ECM.Lay summary: Chronic hepatitis C virus (HCV) infection can lead to hepatocellular carcinoma development in a process that involves derangement of the extracellular matrix (ECM). Herein, we show that heparanase-1, a protein involved in ECM degradation and remodeling, favors HCV infection and is upregulated by HCV infection; this upregulation may result in pathogenic alterations of the ECM.

International audience; Background and Aims: In liver fibrosis, myofibroblasts derive from HSCs and as yet undefined mesenchymal cells. We aimed to identify portal mesenchymal progenitors of myofibroblasts.Approach and Results: Portal mesenchymal cells were isolated from mouse bilio-vascular tree and analyzed by single-cell RNA-sequencing. Thereby, we uncovered the landscape of portal mesenchymal cells in homeostatic mouse liver. Trajectory analysis enabled inferring a small cell population further defined by surface markers used to isolate it. This population consisted of portal fibroblasts with mesenchymal stem cell features (PMSCs), i.e., high clonogenicity and trilineage differentiation potential, that generated proliferative myofibroblasts, contrasting with nonproliferative HSC-derived myofibroblasts (-MF). Using bulk RNA-sequencing, we built oligogene signatures of the two cell populations that remained discriminant across myofibroblastic differentiation. SLIT2, a prototypical gene of PMSC/PMSC-MF signature, mediated profibrotic and angiogenic effects of these cells, which conditioned medium promoted HSC survival and endothelial cell tubulogenesis. Using PMSC/PMSC-MF 7-gene signature and slit guidance ligand 2 fluorescent in situ hybridization, we showed that PMSCs display a perivascular portal distribution in homeostatic liver and largely expand with fibrosis progression, contributing to the myofibroblast populations that form fibrotic septa, preferentially along neovessels, in murine and human liver disorders, irrespective of etiology. We also unraveled a 6-gene expression signature of HSCs/HSC-MFs that did not vary in these disorders, consistent with their low proliferation rate.Conclusions: PMSCs form a small reservoir of expansive myofibroblasts, which, in interaction with neovessels and HSC-MFs that mainly arise through differentiation from a preexisting pool, underlie the formation of fibrotic septa in all types of liver diseases

International audience; Cholangiocarcinoma (CCA) is a rare malignancy that develops at any point along the biliary tree. CCA has a poor prognosis, its clinical management remains challenging, and effective treatments are lacking. Therefore, preclinical research is of pivotal importance and necessary to acquire a deeper understanding of CCA and improve therapeutic outcomes. Preclinical research involves developing and managing complementary experimental models, from in vitro assays using primary cells or cell lines cultured in 2D or 3D to in vivo models with engrafted material, chemically induced CCA or genetically engineered models. All are valuable tools with well-defined advantages and limitations. The choice of a preclinical model is guided by the question(s) to be addressed; ideally, results should be recapitulated in independent approaches. In this Consensus Statement, a task force of 45 experts in CCA molecular and cellular biology and clinicians, including pathologists, from ten countries provides recommendations on the minimal criteria for preclinical models to provide a uniform approach. These recommendations are based on two rounds of questionnaires completed by 35 (first round) and 45 (second round) experts to reach a consensus with 13 statements. An agreement was defined when at least 90% of the participants voting anonymously agreed with a statement. The ultimate goal was to transfer basic laboratory research to the clinics through increased disease understanding and to develop clinical biomarkers and innovative therapies for patients with CCA.

Tight junctions (TJs) are intercellular protein complexes that preserve tissue homeostasis and integrity through the control of paracellular permeability and cell polarity. Recent findings have revealed the functional role of TJ proteins outside TJs and beyond their classical cellular functions as selective gatekeepers. This is illustrated by the dysregulation in TJ protein expression levels in response to external and intracellular stimuli, notably during tumorigenesis. A large body of knowledge has uncovered the well-established functional role of TJ proteins in cancer pathogenesis. Mechanistically, TJ proteins act as bidirectional signaling hubs that connect the extracellular compartment to the intracellular compartment. By modulating key signaling pathways, TJ proteins are crucial players in the regulation of cell proliferation, migration, and differentiation, all of which being essential cancer hallmarks crucial for tumor growth and metastasis. TJ proteins also promote the acquisition of stem cell phenotypes in cancer cells. These findings highlight their contribution to carcinogenesis and therapeutic resistance. Moreover, recent preclinical and clinical studies have used TJ proteins as therapeutic targets or prognostic markers. This review summarizes the functional role of TJ proteins in cancer biology and their impact for novel strategies to prevent and treat cancer. journal article review research support, non-u.s. gov't research support, n.i.h., extramural research support, u.s. gov't, non-p.h.s. 2023 Jan 06 2023 01 06 imported

International audience; In March 2022, a 61-year-old woman in France who had received a heart-lung transplant sought treatment with chronic hepatitis mainly characterized by increased liver enzymes. After ruling out common etiologies, we used metagenomic next-generation sequencing to analyze a liver biopsy sample and identified an unknown species of circovirus, tentatively named human circovirus 1 (HCirV-1). We found no other viral or bacterial sequences. HCirV-1 shared 70% amino acid identity with the closest known viral sequences. The viral genome was undetectable in blood samples from 2017–2019, then became detectable at low levels in September 2020 and peaked at very high titers (10^10 genome copies/mL) in January 2022. In March 2022, we found >10^8 genome copies/g or mL in the liver and blood, concomitant with hepatic cytolysis. We detected HCirV-1 transcripts in 2% of hepatocytes, demonstrating viral replication and supporting the role of HCirV-1 in liver damage.

Analysis of host genetic polymorphisms is an increasingly important tool for understanding and predicting pathogenesis and treatment response of viral diseases. The gene locus of scavenger receptor class B type I (SR-BI), encoding a cell entry factor and receptor for hepatitis C virus (HCV), contains several genetic polymorphisms. We applied a probe extension assay to determine the frequency of six single nucleotide polymorphisms (SNPs) within the SR-BI gene locus in 374 individuals with history of HCV infection. In addition, SR-BI messenger RNA (mRNA) levels were analyzed in liver biopsy specimens of chronically infected HCV subjects. The rs5888 variant allele T was present at a higher frequency in subjects with advanced fibrosis (χ journal article research support, non-u.s. gov't 2023 Jan imported

International audience; Direct oral anticoagulants (DOACs) are recommended for the prevention of thromboembolism in patients with atrial fibrillation (AF), and are now preferred over vitamin K antagonists due to their beneficial efficacy and safety profile. However, all oral anticoagulants carry a risk of gastrointestinal (GI) bleeding. Although the risk is well documented and acute bleeding well codified, there is limited high-quality evidence and no guidelines to guide physicians on the optimal management of anticoagulation after a GI bleeding event. The aim of this review is to provide a multidisciplinary critical discussion of the optimal management of GI bleeding in patients with AF receiving oral anticoagulants to help physicians provide individualized treatment for each patient and optimize outcomes. It is important to perform endoscopy when a patient presents with bleeding manifestations or hemodynamic instability to determine the bleed location and severity of bleeding and then perform initial resuscitation. Administration of all anticoagulants and antiplatelets should be stopped and bleeding allowed to resolve with time; however, anticoagulant reversal should be considered for patients who have life-threatening bleeding or when the bleeding is not controlled by the initial resuscitation. Anticoagulation needs to be timely resumed considering that bleeding risk outweighs thrombotic risk when anticoagulation is resumed early after the bleeding event. To prevent further bleeding, physicians should prescribe anticoagulant therapy with the lowest risk of GI bleeding, avoid medications with GI toxicity, and consider the effect of concomitant medications on potentiating the bleeding risk.

International audience; AIMS: The aims of our study were to assess the best medical and surgical approaches for Perianal Crohn’s Disease (PCD) in order to identify an optimal combined medical and surgical treatment. METHODS: Medical records of all patients with PCD treated with TNFα antagonists in two referral centers between 1998 and 2018 were reviewed. Predictors of long-term outcomes were identified using a Cox proportional hazard model. RESULTS: A total of 200 patients were included. Fifty-three patients (26.5%) were treated with adalimumab and 147 (73.5%) with infliximab. Combination of TNFα antagonist with an immunosuppressant and presence of proctitis were independently associated with fistula closure. Seton was placed in 127 patients (63.5%) before starting biological therapy. Eighty patients (40%) underwent additional perineal surgery. Prior PCD surgery, seton positioning, additional perineal surgery, and additional surgery within 52 weeks of anti-TNFα treatment were associated with an increased rate of fistula closure. Finally, medical combination therapy (anti-TNFα plus immunosuppressant) along with seton placement and additional surgery within one year was the best management for PCD patients (p=0,02). CONCLUSION: Combined medical and surgical management is required for the treatment of PCD patients. Medical combination therapy associated with seton placement and additional surgery within one year is the best management for PCD patients.

International audience; During the course of the infectious disease alveolar echinococcosis (AE), the larval stage of Echinococcus multilocularis develops in the liver, where an initial Th1/Th17 immune response may allow its elimination in resistant individuals. In patients susceptible to infection and disease, the Th2 response initiates later, inducing tolerance to the parasite. The role of interleukin 33 (IL-33), an alarmin released during necrosis and known to drive a Th2 immune response, has not yet been described during AE. Wild-type (WT) and IL-33(-/-) C57BL/6J mice were infected by peritoneal inoculation with E. multilocularis metacestodes and euthanized 4 months later, and their immune response were analyzed. Immunofluorescence staining and IL-33 enzyme-linked immunosorbent assay (ELISA) were also performed on liver samples from human patients with AE. Overall, metacestode lesions were smaller in IL-33(-/-) mice than in WT mice. IL-33 was detected in periparasitic tissues, but not in mouse or human serum. In infected mice, endogenous IL-33 modified peritoneal macrophage polarization and cytokine profiles. Th2 cytokine concentrations were positively correlated with parasite mass in WT mice, but not in IL-33(-/-) mice. In human AE patients, IL-33 concentrations were higher in parasitic tissues than in distant liver parenchyma. The main sources of IL-33 were CD31(+) endothelial cells of the neovasculature, present within lymphoid periparasitic infiltrates together with FOXP3(+) T(reg)s. In the murine model, periparasitic IL-33 correlated with accelerated parasite growth putatively through the polarization of M2-like macrophages and release of immunosuppressive cytokines IL-10 and transforming growth factor β1 (TGF-β1). We concluded that IL-33 is a key alarmin in AE that contributes to the tolerogenic effect of systemic Th2 cytokines. IMPORTANCE Infection with the metacestode stage of Echinococcus multilocularis, known as alveolar echinococcosis, is the most severe cestodosis worldwide. However, less than 1% of exposed individuals, in which the immune system is unable to control the parasite, develop the disease. The factors responsible for this interindividual variability are not fully understood. In this in vivo study comparing wild-type and IL-33(-/-) infected mice, together with data from human clinical samples, we determined that IL-33, an alarmin released following tissue injury and involved in the pathogenesis of cancer and asthma, accelerates the progression of the disease by modulating the periparasitic microenvironment. This suggests that targeting IL-33 could be of interest for the management of patients with AE, and that IL-33 polymorphisms could be responsible for increased susceptibility to AE.

International audience; Silver nanoparticles (AgNP) are heavily used in consumer products and medical devices, including face masks to fight against COVID-19. AgNP effects on mammals have been studied both using cellular and animal models. The former elucidate molecular mechanisms occurring at the subcellular level, while the latter bring insight into the toxicity and accumulation at the organ level. It has not yet been possible to reconcile these two kinds of studies in a translational approach. In the current study, we use 3D HepG2/C3A hepatocyte cultures that partially reproduce liver architecture, leading to the formation of active bile canaliculi and exposure scenarios mimicking parenteral or oral exposure to AgNP. By using a combination of cutting edge imaging techniques, atomic spectroscopy, and cell biology, we reveal the formation of Ag sulphide or Ag-organothiol complexes in the different conditions, the storage of excess Ag into vacuoles, the excretion of Ag(i) ions into bile canaliculi through the ATP7B Cu transporter, and modifications of the mitochondrial network. These findings, made possible by the use of a pseudo-organ as a model, reveal exposure-dependent mechanisms that can inspire future studies on nanomaterial metabolism in mammals and risk-assessment, and thereof regulations. Moreover, they can help bridge the gap between cellular and animal studies, bringing significant advances into the understanding of AgNP fate in mammals.

Background: Advanced stages of cirrhosis are characterized by the occurrence of progressive immune alterations known as CAID (Cirrhosis Associated Immune Dysfunction). In advanced cirrhosis, liver transplantation (LT) remains the only curative treatment. Sepsis, shares many similarities with decompensated cirrhosis in terms of immuno-inflammatory response. In both conditions, the neutrophil-lymphocyte ratio (NLR) is associated with poor outcomes. Based on alterations in sepsis, we hypothesized that we could observe in cirrhotic and LT patients more detailed neutrophil and lymphocyte phenotypes. To this end, along with leukocyte count, we assessed immature neutrophils, LOX-1+ MDSC and PD-1 and TIM-3 lymphocyte expressions in cirrhotic patients before transplantation in association with liver disease severity and during the first month after transplantation.Methods: We conducted a prospective monocentric study including cirrhotic patients registered on LT waiting-list. Blood samples were collected at enrolment before LT and for 1 month post-LT. In addition to NLR, we assessed by whole blood flow cytometry the absolute count of immature neutrophils and LOX-1+ MDSC as well as the expressions of immune checkpoint receptors PD-1 and TIM-3 on T lymphocytes.Results: We included 15 healthy volunteers (HV) and 28 patients. LT was performed for 13 patients. Pre-LT patients presented with a higher NLR compared to HV and NLR was associated with cirrhosis severity. Increased immature neutrophils and LOX-1+ MDSC counts were observed in the most severe patients. These alterations were mainly associated with acute decompensation of cirrhosis. PD-1 and TIM-3 expressions on T lymphocytes were not different between patients and HV. Post-LT immune alterations were dominated by a transitory but tremendous increase of NLR and immature neutrophils during the first days post-LT. Then, immune checkpoint receptors and LOX-1+ MDSC tended to be overexpressed by the second week after surgery.Conclusion: The present study showed that NLR, immature neutrophils and LOX-1+ MDSC counts along with T lymphocyte count and checkpoint inhibitor expression were altered in cirrhotic patients before and after LT. These data illustrate the potential interest of immune monitoring of cirrhotic patients in the context of LT in order to better define risk of sepsis. For this purpose, larger cohorts of patients are now necessary in order to move forward a more personalised care of LT patients.

International audience; Deregulated lipid metabolism is a common feature of liver cancers needed to sustain tumor cell growth and survival. We aim at taking advantage of this vulnerability and rewiring the oncogenic metabolic hub by targeting the key metabolic player pro-protein convertase subtilisin/kexin type 9 (PCSK9). We assessed the effect of PCSK9 inhibition using the three hepatoma cell lines Huh6, Huh7 and HepG2 and validated the results using the zebrafish in vivo model. PCSK9 deficiency led to strong inhibition of cell proliferation in all cell lines. At the lipid metabolic level, PCSK9 inhibition was translated by an increase in intracellular neutral lipids, phospholipids and polyunsaturated fatty acids as well as a higher accumulation of lipid hydroperoxide. Molecular signaling analysis involved the disruption of the sequestome 1/Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor 2 (p62/Keap1/Nrf2) antioxidative axis, leading to ferroptosis, for which morphological features were confirmed by electron and confocal microscopies. The anti-tumoral effects of PCSK9 deficiency were validated using xenograft experiments in zebrafish. The inhibition of PCSK9 was effective in disrupting the oncometabolic process, inducing metabolic exhaustion and enhancing the vulnerability of cancer cells to iron-triggered lipid peroxidation. We provide strong evidence supporting the drug repositioning of anti-PCSK9 approaches to treat liver cancers.

International audience; Alterations in lipid handling are an important hallmark in cancer. Our aim here is to target key metabolic enzymes to reshape the oncogenic lipid metabolism triggering irreversible cell breakdown. We targeted the key metabolic player proprotein convertase subtilisin/kexin type 9 (PCSK9) using a pharmacological inhibitor (R-IMPP) alone or in combination with 3-hydroxy 3-methylglutaryl-Coenzyme A reductase (HMGCR) inhibitor, simvastatin. We assessed the effect of these treatments using 3 hepatoma cell lines, Huh6, Huh7 and HepG2 and a tumor xenograft in chicken choriorallantoic membrane (CAM) model. PCSK9 deficiency led to dose-dependent inhibition of cell proliferation in all cell lines and a decrease in cell migration. Co-treatment with simvastatin presented synergetic anti-proliferative effects. At the metabolic level, mitochondrial respiration assays as well as the assessment of glucose and glutamine consumption showed higher metabolic adaptability and surge in the absence of PCSK9. Enhanced lipid uptake and biogenesis led to excessive accumulation of intracellular lipid droplets as revealed by electron microscopy and metabolic tracing. Using xenograft experiments in CAM model, we further demonstrated the effect of anti-PCSK9 treatment in reducing tumor aggressiveness. Targeting PCSK9 alone or in combination with statins deserves to be considered as a new therapeutic option in liver cancer clinical applications.

International audience; Metabolic rewiring and defective immune responses are considered to be the main driving forces sustaining cell growth and oncogenesis in many cancers. The atypical enzyme, proprotein convertase subtilisin/kexin type 9 (PCSK9), is produced by the liver in large amounts and plays a major role in lipid metabolism via the control of the low density lipoprotein receptor (LDLR) and other cell surface receptors. In this context, many clinical studies have clearly demonstrated the high efficacy of PCSK9 inhibitors in treating hyperlipidemia and cardiovascular diseases. Recent data implicated PCSK9 in the degradation of major histocompatibility complex I (MHC-I) receptors and the immune system as well as in other physiological activities. This review highlights the complex crosstalk between PCSK9, lipid metabolism and immunosuppression and underlines the latest advances in understanding the involvement of this convertase in other critical functions. We present a comprehensive assessment of the different strategies targeting PCSK9 and show how these approaches could be extended to future therapeutic options to treat cancers with a main focus on the liver.

International audience; Background Despite an effective vaccine, hepatitis B remains a major global health problem due to its significant morbidity and mortality. Vaccination in immunosuppressed patients such as those treated for an inflammatory bowel disease (IBD) can be less effective. This case describes an uncommon original diagnosis of an acute hepatitis B infection occurring in a vaccinated but immunocompromised IBD patient under long-term infliximab treatment. A low anti-HBs titer and the presence of HBsAg escape mutations are possible hypotheses to explain this unexpected infection.Case presentation A 28-year-old Caucasian male, regularly followed-up for a Crohn's disease treated by infliximab, was regularly screened for sexually transmissible infections because of at-risk behaviors. Despite a correct immunization scheme against hepatitis B virus (HBV), an active HBV infection was diagnosed during one of those screenings. Retrospective testing of a sample collected 6 months earlier was in favor of an evolution from an acute hepatitis B toward a chronic hepatitis B. The patient has always had a low anti-HBs antibody levels (near the threshold of 10 IU/L) possibly explaining his infection. In addition, HBV sequencing revealed a genotype A2 HBV strain, carrying the sD144A substitution on the S protein, known as a potential immune escape variant. Dual therapy combining tenofovir disoproxil fumarate and emtricitabine, active against HBV but also efficient as an HIV pre-exposure prophylaxis, was initiated. Ten months after treatment initiation, all surrogate biochemical and virological endpoints for HBV functional cure were achieved. Treatment and periodical monitoring are being maintained.Conclusion Emphasis should be placed on HBV screening, vaccination and regular monitoring of patients under long-term immunosuppressive therapy, particularly those with at-risk behaviors.

Oncogene activation leads to replication stress and promotes genomic instability. Here we combine optical mapping and whole-genome sequencing (WGS) to explore in depth the nature of structural variants (SV) induced by replication stress in cyclin-activated hepatocellular carcinomas (CCN-HCC). In addition to classical tandem duplications, CCN-HCC displayed frequent intra-chromosomal and interchromosomal templated insertion cycles (TIC), likely resulting from template switching events. Template switching preferentially involves active topologically associated domains that are proximal to one another within the 3D genome. Template sizes depend on the type of cyclin activation and are coordinated within each TIC. Replication stress induced continuous accumulation of SVs during CCN-HCC progression, fostering the acquisition of new driver alterations and large-scale copy-number changes at TIC borders. Together, this analysis sheds light on the mechanisms, dynamics, and consequences of SV accumulation in tumors with oncogene-induced replication stress. Significance: Optical mapping and whole-genome sequencing integration unravels a unique signature of replication stress–induced structural variants that drive genomic evolution and the acquisition of driver events in CCN-HCC.

Chronic liver diseases, resulting from chronic injuries of various causes, lead to cirrhosis with life-threatening complications including liver failure, portal hypertension, hepatocellular carcinoma. A key unmet medical need is robust non-invasive biomarkers to predict patient outcome, stratify patients for risk of disease progression and monitor response to emerging therapies. Quantitative imaging biomarkers have already been developed, for instance, liver elastography for staging fibrosis or proton density fat fraction on magnetic resonance imaging for liver steatosis. Yet, major improvements, in the field of image acquisition and analysis, are still required to be able to accurately characterize the liver parenchyma, monitor its changes and predict any pejorative evolution across disease progression. Artificial intelligence has the potential to augment the exploitation of massive multi-parametric data to extract valuable information and achieve precision medicine. Machine learning algorithms have been developed to assess non-invasively certain histological characteristics of chronic liver diseases, including fibrosis and steatosis. Although still at an early stage of development, artificial intelligence-based imaging biomarkers provide novel opportunities to predict the risk of progression from early-stage chronic liver diseases toward cirrhosis-related complications, with the ultimate perspective of precision medicine. This review provides an overview of emerging quantitative imaging techniques and the application of artificial intelligence for biomarker discovery in chronic liver disease. journal article review 2022 Jun 2022 02 09 imported

The Mendelian inheritance pattern of acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria is autosomal dominant, but the clinical phenotype is heterogeneous. Within the general population, penetrance is low, but among first-degree relatives of a symptomatic proband, penetrance is higher. These observations suggest that genetic factors, in addition to mutation of the specific enzyme of the biosynthetic pathway of heme, contribute to the clinical phenotype. Recent studies by others suggested that the genotype of the transporter protein ABCB6 contribute to the porphyria phenotype. Identifying the molecule(s) that are transported by ABCB6 has been problematic and has led to uncertainty with respect to how or if variants/mutants contribute to phenotypic heterogeneity. Knockout mouse models of Abcb6 have not provided a direction for investigation as homozygous knockout animals do not have a discrete phenotype. To address the proposed link between ABC6 genotype and porphyria phenotype, a large cohort of patients with acute hepatic porphyria and erythropoietic protoporphyria was analyzed. Our studies showed that ABCB6 genotype did not correlate with disease severity. Therefore, genotyping of ABCB6 in patients with acute hepatic porphyria and erythropoietic protoporphyria is not warranted.

The results of this study were presented during the 13th Congress of the E-AHPBA on June 3th 2019, in Amsterdam.; International audience; BACKGROUND: Major bile duct injuries (BDI) following cholecystectomy require complex reconstructive surgery. The aim was to collect the liver transplantations (LT) performed in France for major BDI following cholecystectomy, to analyze the risk factors and to report the results. METHODS: National multicenter observational retrospective study. All the patients who underwent a LT in France between 1994 and 2017, for BDI following cholecystectomy, were included. RESULTS: 30 patients were included. 25 BDI occurred in non hepato-biliary expert centers, 20 were initially treated in these centers. Median time between injury and LT was 3 years in case of an associated vascular injury (11 injuries), versus 11.7 years without vascular injury (p = 0.006). Post-transplant morbidity rate was 86.7%, mortality 23.5% at 5 years. CONCLUSION: Iatrogenic BDI remains a real concern with severe cases, associated with vascular damages or leading to cirrhosis, with no solution but LT. It is associated with high morbidity and not optimal results. This enlights the necessity of early referral of all major BDI in expert centers to prevent dramatic outcome. Decision to perform transplantation should be taken before dismal infectious situations or biliary cirrhosis and access to graft should be facilitated by Organ Sharing Organizations.

International audience

International audience; BACKGROUND & AIMS: NADPH oxidase 1 (NOX1) has emerged as a prime regulator of intestinal mucosa immunity and homeostasis. Dysregulation of NOX1 may cause inflammatory bowel disease (IBD). It is not clear how NOX1 is regulated in vivo under inflammatory conditions. We studied the role of CK2 in this process.METHODS: The NOX1 organizer subunit, NADPH oxidase organizer 1 (NOXO1), was immunoprecipitated from cytokine-treated colon epithelial cells, and bound proteins were identified by mass spectrometry analysis. Sites on NOXO1 phosphorylated by CK2 were identified by nanoscale liquid chromatography coupled to tandem mass spectrometry. NOX1 activity was determined in colon epithelial cells and colonoids in the presence or absence of CX-4945, a CK2 specific inhibitor. Acute colitis was induced by administration of trinitrobenzenesulfonic acid in mice treated or not with CX-4945. Colon tissues were analyzed by histologic examination, quantitative polymerase chain reaction, and Western blots. CK2 activity, markers of inflammation, and oxidative stress were assessed.RESULTS: We identified CK2 as a major partner of NOXO1 in colon epithelial cells under inflammatory conditions. CK2 directly binds NOXO1 at the C-terminus containing the Phox homology domain and phosphorylates NOXO1 on several sites. CX-4945 increased ROS generation by NOX1 in human colon epithelial cells and organoids. Strikingly, CK2 activity was reduced in trinitrobenzenesulfonic acid-induced acute colitis, and CX-4945 exacerbated colitis inflammation as shown by increased levels of CXCL1, ROS generation, lipid peroxidation, and colon damage.CONCLUSIONS: The ubiquitous protein kinase CK2 limits NOX1 activity via NOXO1 binding and phosphorylation in colonic epithelial cells and lessens experimental colitis. Loss of CK2 activity during acute colitis results in excessive ROS production, contributing to the pathogenesis. Strategies to activate CK2 could be an effective novel therapeutic approach in IBD.

International audience; Aim: The transcription factor RIP140 (receptor interacting protein of 140 kDa) is involved in intestinal tumorigenesis. It plays a role in the control of microsatellite instability (MSI), through the regulation of MSH2 and MSH6 gene expression. The aim of this study was to explore its effect on the expression of POLK, the gene encoding the specialized translesion synthesis (TLS) DNA polymerase κ known to perform accurate DNA synthesis at microsatellites.Methods: Different mouse models and engineered human colorectal cancer (CRC) cell lines were used to analyze by RT-qPCR, while Western blotting and luciferase assays were used to elucidate the role of RIP140 on POLK gene expression. Published DNA microarray datasets were reanalyzed. The in vitro sensitivity of CRC cells to methyl methane sulfonate and cisplatin was determined.Results: RIP140 positively regulates, at the transcriptional level, the expression of the POLK gene, and this effect involves, at least partly, the p53 tumor suppressor. In different cohorts of CRC biopsies (with or without MSI), a strong positive correlation was observed between RIP140 and POLK gene expression. In connection with its effect on POLK levels and the TLS function of this polymerase, the cellular response to methyl methane sulfonate was increased in cells lacking the Rip140 gene. Finally, the association of RIP140 expression with better overall survival of CRC patients was observed only when the corresponding tumors exhibited low levels of POLK, thus strengthening the functional link between the two genes in human CRC.Conclusion: The regulation of POLK gene expression by RIP140 could thus contribute to the maintenance of microsatellite stability, and more generally to the control of genome integrity.

MicroRNAs [miRNAs], small non-coding RNAs, have recently been described as crucial contributors to intestinal homeostasis. They can interact with the gut microbiota in a reciprocal manner and deeply affect host health status, leading to several disorders when unbalanced. Inflammatory bowel disease [IBD] is a chronic inflammation of the gastrointestinal tract that co-occurs with alterations of the gut microbiota, and whose aetiology remains largely unclear. On one hand, host miRNA could be playing a relevant role in IBD pathophysiology by shaping the gut microbiota. The gut microbiome, on the other hand, may regulate the expression of host miRNAs, resulting in intestinal epithelial dysfunction, altered autophagy, and immune hyperactivation. Interestingly, it has been hypothesised that their reciprocal impact may be used for therapeutic goals. This review describes the latest research and suggests mechanisms through which miRNA and intestinal microbiota, as joint actors, may participate specifically in IBD pathophysiology. Furthermore, we discuss the diagnostic power and therapeutic potential resulting from their bidirectional communication after faecal transplantation, probiotics intake, or anti-miRNAs or miRNA mimics administration. The current literature is summarised in the present work in a comprehensive manner, hoping to provide a better understanding of the miRNA-microbiota cross-talk and to facilitate their application in IBD.

International audience; Background and Aims: Hepatitis E virus (HEV) is one of the most common causes of acute hepatitis worldwide. Its positive-strand RNA genome encodes three open reading frames (ORF). ORF1 is translated into a large protein composed of multiple domains and known as the viral replicase. The RNA-dependent RNA polymerase (RdRp) domain is responsible for the synthesis of viral RNA.Approach and Results: Here, we identified a highly conserved α-helix located in the RdRp thumb subdomain. Nuclear magnetic resonance demonstrated an amphipathic α-helix extending from amino acids 1628 to 1644 of the ORF1 protein. Functional analyses revealed a dual role of this helix in HEV RNA replication and virus production, including assembly and release. Mutations on the hydrophobic side of the amphipathic α-helix impaired RNA replication and resulted in the selection of a second-site compensatory change in the RdRp palm subdomain. Other mutations enhanced RNA replication but impaired virus assembly and/or release.Conclusions: Structure-function analyses identified a conserved amphipathic α-helix in the thumb subdomain of the HEV RdRp with a dual role in viral RNA replication and infectious particle production. This study provides structural insights into a key segment of the ORF1 protein and describes the successful use of reverse genetics in HEV, revealing functional interactions between the RdRp thumb and palm subdomains. On a broader scale, it demonstrates that the HEV replicase, similar to those of other positive-strand RNA viruses, is also involved in virus production

Objective To investigate whether oral antimicrobial prophylaxis as an adjunct to intravenous antibiotic prophylaxis reduces surgical site infections after elective colorectal surgery. Design Multicentre, randomised, double blind, placebo controlled trial. Setting 11 university and non-university hospitals in France between 25 May 2016 and 8 August 2019. Participants 926 adults scheduled for elective colorectal surgery. Intervention Patients were randomised to receive either a single 1 g dose of ornidazole (n=463) or placebo (n=463) orally 12 hours before surgery, in addition to intravenous antimicrobial prophylaxis before surgical incision. Main outcome measures The primary outcome was the proportion of patients with surgical site infection within 30 days after surgery. Secondary outcomes included individual types of surgical site infections and major postoperative complications (Clavien-Dindo classification grade 3 or higher) within 30 days after surgery. Results Of the 960 patients who were enrolled, 926 (96%) were included in the analysis. The mean age of participants was 63 years and 554 (60%) were men. Surgical site infection within 30 days after surgery occurred in 60 of 463 patients (13%) in the oral prophylaxis group and 100 of 463 (22%) in the placebo group (absolute difference −8.6%, 95% confidence interval −13.5% to −3.8%; relative risk 0.60, 95% confidence interval 0.45 to 0.80). The proportion of patients with deep infections was 4.8% in the oral prophylaxis group and 8.0% in the placebo group (absolute difference −3.2%, 95% confidence interval −6.4% to −0.1%). The proportion of patients with organ space infections was 5.0% in the oral prophylaxis group and 8.4% in the placebo group (absolute difference −3.4%, −6.7% to −0.2%). Major postoperative complications occurred in 9.1% patients in the oral prophylaxis group and 13.6% in the placebo group (absolute difference −4.5%, −8.6% to −0.5%). Conclusion Among adults undergoing elective colorectal surgery, the addition of a single 1 g dose of ornidazole compared with placebo before surgery significantly reduced surgical site infections. Trial registration ClinicalTrials.gov NCT02618720 .

International audience; Background: The identification of early prognostic factors during Crohn's disease (CD) remains needed for physician decision-making to minimize structural bowel damage, which this study aimed to assess in a population-based setting. Methods: All incident cases of CD were prospectively registered from 1994 to 1997 in Brittany, a limited area of France. All charts of patients were reviewed from the diagnosis to the last clinic visit in 2015. Disabling CD course was defined according to the Saint-Antoine criteria. Results: Among the 331 incident cases of CD, 272 (82%) were followed-up for a median time of 12.8 years. The cumulative probability of developing stricturing or fistulizing CD was 66% at 15 years, and 107 (39%) patients underwent surgery. The cumulative probabilities of immunosuppressant and TNF antagonist use at 15 years were 37% and 22%, respectively. The cumulative risks for disabling disease and bowel damage were 74% and 71% at 15 years, respectively. Systemic symptoms and perianal lesions at diagnosis were independently associated with a disabling disease course. Perianal disease and short disease extension were associated with the onset of bowel damage. Deep ulcers was not predictive of any outcome. Conclusions: A disabling disease course and bowel damage occurred early in the course of CD, which suggests the need for early diagnosis and early treatment, particularly for patients with systematic symptoms and perianal disease.

International audience; No abstract available

BACKGROUND: Abnormal oroanal transit time (OATT) and visceral hypersensitivity are key pathophysiological factors in irritable bowel syndrome (IBS). The lactulose nutrient challenge test (LNCT) has been developed to assess the postprandial symptoms and gut microbial fermentation. We aimed to investigate associations between OATT, rectal sensitivity, and LNCT in IBS patients. METHODS: We included 263 IBS patients from two study cohorts, where the link between pathophysiology and symptoms was investigated. During the LNCT, severity of postprandial symptoms was graded, and breath hydrogen/methane concentrations were measured after ingestion of a combined lactulose nutrient drink every 15 min for 4 h. The patients underwent rectal sensitivity (rectal barostat) and OATT (radiopaque markers) investigations. Comorbid conditions (functional dyspepsia, anxiety, depression, and somatization) were assessed with questionnaires. KEY RESULTS: After controlling for comorbid conditions, rectal sensitivity was associated with abdominal pain (p

International audience; Environmental enteric dysfunction (EED) is an inflammatory syndrome postulated to contribute to stunted child growth and to be associated with intestinal dysbiosis and nutrient malabsorption. However, the small intestinal contributions to EED remain poorly understood. This study aimed to assess changes in the proximal and distal intestinal microbiota in the context of stunting and EED and to test for a causal role of these bacterial isolates in the underlying pathophysiology. We performed a cross-sectional study in two African countries recruiting roughly 1,000 children aged 2 to 5 years and assessed the microbiota in the stomach, duodenum, and feces. Upper gastrointestinal samples were obtained from stunted children and stratified according to stunting severity. Fecal samples were collected. We then investigated the role of clinical isolates in EED pathophysiology using tissue culture and animal models. We find that small intestinal bacterial overgrowth (SIBO) is extremely common (>80%) in stunted children. SIBO is frequently characterized by an overgrowth of oral bacteria, leading to increased permeability and inflammation and to replacement of classical small intestinal strains. These duodenal bacterial isolates decrease lipid absorption in both cultured enterocytes and mice, providing a mechanism by which they may exacerbate EED and stunting. Further, we find a specific fecal signature associated with the EED markers fecal calprotectin and alpha-antitrypsin. Our study shows a causal implication of ectopic colonization of oral bacterial isolated from the small intestine in nutrient malabsorption and gut leakiness in vitro. These findings have important therapeutic implications for modulating the microbiota through microbiota-targeted interventions.

On-Alcoholic Fatty Liver Disease (NAFLD) has become the leading cause of chronic liver disease. Its overall prevalence is estimated between 25% and 45% with strong disparities depending on the regions of the world, superimposable on the epidemiology of obesity and diabetes. It is fast becoming the leading cause of liver transplantation. However, epidemiological data on NAFLD in the general population are lacking. In France, no overall epidemiological data is available, apart from modeling studies. Only 21.5% of patients with NAFLD are diagnosed, thus limiting the understanding of its determinants and its burden on health indicators. This thesis aims to estimate the prevalence of NAFLD in France, to identify its determinants and to assess its impact on the health of the general population. For this, three lines of study have been developed to analyze 1) its prevalence and its risk factors, 2) its impact on morbidity and mortality and finally 3) the subgroups of populations likely to be particularly vulnerable. Thus, a first study conducted on a large representative sample allowed us to estimate the prevalence of NAFLD and fibrosis as well as the risk factors associated with them. Following this initial work, we conducted several analyzes aimed at assessing the burden of NAFLD on morbidity and mortality in the general population. The first two studies focused on the entire general population with, however, two different patterns. First, we assessed the association between NAFLD and a history of extra-hepatic comorbidities such as cardiovascular events, extra-hepatic cancers and grade III renal failure. Secondly, we analyzed the impact of NAFLD on the incidence of hepatic (cirrhosis, hepatocellular carcinoma, liver transplantation) and extra-hepatic complications as well as all-cause mortality. In both cases, NAFLD was associated with a very strong increase in hepatic and extra-hepatic morbidity and mortality, regardless of the level of severity of liver damage (fibrosis), but with a gradient effect according to the degree of hepatic fibrosis. Although representing real progress for a global awareness of the problem of NAFLD, the lack of effective pharmacological treatment and the absence of evidence of the benefit of systematic screening constitute some potential limitations. However, data from the literature show that early diagnosis and appropriate management such as weight loss in obese subjects could be beneficial for disease progression. This raises the question of identifying subpopulations that can benefit from proactive strategies due to the higher risk of disease progression. Thus, our third axis of study wanted to answer this problem by focusing on diabetic subjects, because of the strong interaction between the two nosological entities. This analysis showed a strong association between the coexistence of diabetes and NAFLD on morbidity and mortality. It shows in particular that the interaction between the epidemiologies of NAFLD and diabetes as well as their impact on morbidity and mortality were mediated by their respective age and severity. This suggests the need for early detection and management of these diseases. In addition, it turns out that certain anti-diabetic drugs improve insulin sensitivity and therefore could also be beneficial for the progression of NAFLD. Future studies to precisely assess the clinical and medico-economic benefits and the criteria for implementing systematic and/or targeted screening for metabolic steatosis are needed pending effective treatments. This work shows that NAFLD has become a major health problem, which only a political leap and diligent public health programs could contain., La NAFLD est devenue la première cause de maladies chroniques du foie. Sa prévalence globale est estimée entre 25% et 45% avec de fortes disparités selon les régions du monde, superposables à l’épidémiologie de l’obésité et du diabète. Elle est en passe de devenir la première cause de transplantation hépatique. Cependant, les données épidémiologiques sur la NAFLD en population générale font défaut. En France, aucune donnée épidémiologique globale n’est disponible, en dehors d’études de modélisation. Seuls 21,5% des patients atteints de NAFLD sont diagnostiqués, limitant ainsi la compréhension de ses déterminants et son fardeau sur les indicateurs de santé. Cette thèse a pour objectif d’estimer la prévalence de la NAFLD en France, d’en identifier les déterminants et d’évaluer son impact sur la santé de la population générale. Pour cela, trois axes d’étude ont été développés pour analyser 1) sa prévalence et ses facteurs de risque, 2) son impact sur la morbi-mortalité et enfin 3) les sous-groupes de populations susceptibles d’y être particulière vulnérables. Ainsi, une première étude menée sur un grand échantillon réprésentatif nous a permis d’estimer la prévalence de la NAFLD et de la fibrose ainsi que les facteurs de risque qui leur sont associés. À la suite de ce premier travail, nous avons évaluer le fardeau de la stéatose métabolique sur la morbi-mortalité en population. Dans un premier temps, nous avons évalué l’association entre la NAFLD et les antécédents de comorbidités extra-hépatiques tels que les accidents cardiovasculaires, les cancers extra-hépatiques et l’insuffisance rénale de grade III. Dans un second temps, nous avons analysé l’impact de la NAFLD sur l’incidence des complications hépatiques et extra-hépatiques ainsi que la mortalité toutes causes confondues. Dans les deux cas, la NAFLD était associée à une très forte augmentation de la morbi-mortalité hépatique et extra-hépatique et ce, quel que soit le niveau de sévérité de l’atteinte hépatique (fibrose), mais avec un effet de gradient selon le degré de la fibrose hépatique. Bien que représentant un véritable progrès pour une prise de conscience globale sur la problématique de la NAFLD, le manque de traitement pharmacologique efficace et l’absence de preuves d’un bénéfice du dépistage systématique constituent quelques limites potentielles. Cependant, les données de la littérature montrent qu’un diagnostic précoce et une prise en charge adaptée comme par exemple la perte de poids chez les sujets obèses pourraient être bénéfiques sur la progression de la maladie. Se pose alors la question de l’identification des sous-populations pouvant bénéficier de stratégies proactives du fait du risque plus élevé de progression de la maladie. Ainsi notre troisième axe d'étude a voulu répondre à cette problématique en se focalisant sur les sujets diabétiques, en raison de la forte interaction entre les deux entités nosologiques. Cette analyse a permis de montrer une forte association entre coexistence du diabète et de la NAFLD sur la morbi-mortalité. Elle montre en particulier que l’interaction entre les épidémiologies de la NAFLD et du diabète ainsi que leur impact sur la morbi-mortalité étaient médiés par leur ancienneté et leur sévérité respectives. Ceci suggère la nécessité d’un dépistage et une prise en charge précoce de ces maladies. De plus, il s’avère que certains médicaments anti-diabétiques améliorent la sensibilité à l’insuline et donc pourraient être bénéfiques également sur la progression de la NAFLD. De futures études permettant d’évaluer précisément les bénéfices cliniques, médico-économiques et les critères de la mise en place d’un dépistage systématique et/ou ciblé de la stéatose métabolique, sont nécessaires en attendant des traitements efficaces. Ces travaux montrent que la stéatose métabolique est devenue un problème majeur de santé, que seul un sursaut politique et des programmes diligents de santé publique permettraient de contenir.

Epidemiological projections point to acquisition of ever-expanding multidrug resistance (MDR) byiEscherichia coli/i, a commensal of the digestive tract and a source of urinary tract pathogens. Bioinformatics analyses of a large collection ofiE. coli/igenomes from EnteroBase, enriched in clinical isolates of worldwide origins, suggest the Cytotoxic Necrotizing Factor 1 (CNF1)-toxin encoding gene,icnf1/i, is preferentially distributed in four common sequence types (ST) encompassing the pandemiciE. coli/iMDR lineage ST131. This lineage is responsible for a majority of extraintestinal infections that escape first-line antibiotic treatment, with known enhanced capacities to colonize the gastrointestinal tract. Statistical projections based on this dataset point to a global expansion oficnf1/i-positive multidrug-resistant ST131 strains from subcladeiH/i30Rx/C2, accounting for a rising prevalence oficnf1/i-positive strains in ST131. Despite the absence of phylogeographical signals,icnf1/i-positive isolates segregated into clusters in the ST131-iH/i30Rx/C2 phylogeny, sharing a similar profile of virulence factors and the sameicnf1/iallele. The suggested dominant expansion oficnf1/i-positive strains in ST131-iH/i30Rx/C2 led us to uncover the competitive advantage conferred byicnf1/ifor gut colonization to the clinical strain EC131GY ST131-iH/i30Rx/C2 versusicnf1/i-deleted isogenic strain. Complementation experiments showed that colon tissue invasion was compromised in the absence of deamidase activity on Rho GTPases by CNF1. Hence, gut colonization factor function oficnf1/iwas confirmed for another clinical strain ST131-iH/i30Rx/C2. In addition, functional analysis of theicnf1/i-positive clinical strain EC131GY ST131-iH/i30Rx/C2 and aicnf1/i-deleted isogenic strain showed no detectable impact of the CNF1 gene on bacterial fitness and inflammation during the acute phase of bladder monoinfection. Together these data argue for an absence of role of CNF1 in virulence during UTI, while enhancing gut colonization capacities of ST131-iH/i30Rx/C2 and suggested expansion oficnf1/i-positive MDR isolates in subclade ST131-iH/i30Rx/C2.

ObjectivesMalnutrition is common in children with biliary atresia (BA) awaiting liver transplantation (LT). Few studies have evaluated the effectiveness of enteral nutrition (EN) in these patients. The objective of this work was to assess the efficacy and tolerance of EN in children with BA awaiting LT.MethodsA total of 31 patients with BA followed between 1995 and 2018 were retrospectively included. Anthropometric indicators (weight, length, and head circumference) and adverse effects of EN were noted at the start (T0) and the end (T1) of EN. The z-scores for anthropometric indicators were compared between T0 and T1.ResultsThe median age at T0 was 7 months (interquartile range [IQR] 5–9), and the median duration of EN was 9 months (IQR 3–17). The z-scores for anthropometric variables improved from T0 to T1: –1.6 (IQR –2.5 to –1.0) to –0.5 (IQR –1.8 to 0.3) for median weight for age; –1.3 (IQR –2.4 to 0) to –0.4 (IQR –2.0 to 0.7) for length for age; –0.9 (IQR –2.3 to –0.3) to –0.3 (IQR –1.2 to 0.1) for weight for length; and –1.2 (IQR –2.1 to –0.6) to –0.2 (IQR –1.6 to 0.4) for body mass index (p < 0.05 for all comparisons). Nearly all (94%) of the patients had a weight-for-length z-score > –2 at the end of EN; 23% had adverse effects and 10% had complications leading to the cessation of EN.ConclusionEN is effective and well tolerated in infants with BA awaiting LT.

International audience; Human expansion in space is hampered by the physiological risks of spaceflight. The muscle and the liver are among the most affected tissues during spaceflight and their relationships in response to space exposure have never been studied. We compared the transcriptome response of liver and quadriceps from mice on NASA RR1 mission, after 37 days of exposure to spaceflight using GSEA, ORA, and sparse partial least square-differential analysis. We found that lipid metabolism is the most affected biological process between the two organs. A specific gene cluster expression pattern in the liver strongly correlated with glucose sparing and an energy-saving response affecting high energy demand process gene expression such as DNA repair, autophagy, and translation in the muscle. Our results show that impaired lipid metabolism gene expression in the liver and muscle atrophy gene expression are two paired events during spaceflight, for which dietary changes represent a possible countermeasure.

Editorial Material; International audience; No abstract available

Background & Aims: Acute decompensation (AD) of cirrhosis is a heterogeneous clinical entity associated with moderate mortality. In some patients, this condition develops quickly into the more deadly acute-on-chronic liver failure (ACLF), in which other organs such as the kidneys or brain fail. The aim of this study was to characterize the blood lipidome in a large series of patients with cirrhosis and identify specific signatures associated with AD and ACLF development. Methods: Serum untargeted lipidomics was performed in 561 patients with AD (518 without and 43 with ACLF) (discovery cohort) and in 265 patients with AD (128 without and 137 with ACLF) in whom serum samples were available to perform repeated measurements during the 28-day follow-up (validation cohort). Analyses were also performed in 78 patients with AD included in a therapeutic albumin trial (43 patients with compensated cirrhosis and 29 healthy individuals). Results: The circulating lipid landscape associated with cirrhosis was characterized by a generalized suppression, which was more manifest during AD and in non-surviving patients. By computing discriminating accuracy and the variable importance projection score for each of the 223 annotated lipids, we identified a sphingomyelin fingerprint specific for AD of cirrhosis and a distinct cholesteryl ester and lysophosphatidylcholine finger-print for ACLF. Liver dysfunction and infections were the prin-cipal net contributors to these fingerprints, which were dynamic and interchangeable between patients with AD whose condition worsened to ACLF and those who improved. Notably, blood lysophosphatidylcholine levels increased in these patients after albumin therapy. Conclusions: Our findings provide insights into the lipid land-scape associated with decompensation of cirrhosis and ACLF progression and identify unique non-invasive diagnostic bio-markers of advanced cirrhosis. Lay summary: Analysis of lipids in blood from patients with advanced cirrhosis reveals a general suppression of their levels in the circulation of these patients. A specific group of lipids known as sphingomyelins are useful to distinguish between patients with compensated and decompensated cirrhosis. Another group of lipids designated cholesteryl esters further distinguishes patients with decompensated cirrhosis who are at risk of developing organ failures. (c) 2021 The Authors. Published by Elsevier B.V. on behalf of European Association for the Study of the Liver.

International audience; Background and AimsThe identification of Crohn's disease (CD)-associated adherent and invasive Escherichia coli (AIEC) is time-consuming and requires ileal biopsies. We aimed to identify a faster and less invasive methods to detect ileal colonization by AIEC in CD patients.MethodsCD patients requiring ileo-colonoscopy were consecutively enrolled in this prospective multicenter study. Samples from saliva, serum, stools, and ileal biopsies of CD patients were collected.ResultsAmong 102 CD patients, the prevalence of AIEC on ileal biopsies was 24.5%. The abundance and global invasive ability of ileal-associated total E. coli were respectively ten-fold (p = 0.0065) and two-fold (p = 0.0007) higher in AIEC-positive (vs. AIEC-negative), while abundance of total E. coli in the feces was not correlated with AIEC status in the ileum. The best threshold of ileal total E. coli was 60 cfu/biopsy to detect AIEC-positive patients, with high negative predictive value (NPV) (94.1%[80.3–99.3]), while the global invasive ability (>9000 internalized bacteria) was able to detect the presence of AIEC with high positive predictive value (80.0% [55.2–100.0]). Overall, 78.1% of the AIEC + patients were colonized by two or less different AIEC strains. The level of serum anti-total E. coli antibodies (AEcAb) was higher in AIEC-positive patients (p = 0.038) with a very high negative predictive value (96.6% [89.9–100.0]) (p = 0.038) for a cut-off value > 1.9 × 10−3.ConclusionsMore than two thirds of AIEC-positive CD patients were colonized by two or less AIEC strains. While stools samples are not accurate to screen AIEC status, the AEcAb level appears to be an attractive, rapid and easier biomarker to identify patients with Crohn's disease harboring AIEC.

Background Acute pancreatitis after liver resection is a rare but serious complication, and few cases have been described in the literature. Extended lymphadenectomy, and long ischemia due to the Pringle maneuver could be responsible of post-liver resection acute pancreatitis, but the exact causes of AP after hepatectomy remain unclear. Cases presentation We report here three cases of AP after hepatectomy and we strongly hypothesize that this is due to the bile leakage white test. 502 hepatectomy were performed at our center and 3 patients (0.6%) experienced acute pancreatitis after LR and all of these three patients underwent the white test at the end of the liver resection. None underwent additionally lymphadenectomy to the liver resection. All patient had a white-test during the liver surgery. We identified distal implantation of the cystic duct in these three patients as a potential cause for acute pancreatitis. Conclusion The white test is useful for detection of bile leakage after liver resection, but we do not recommend a systematic use after LR, because severe acute pancreatitis can be lethal for the patient, especially in case of distal cystic implantation which may facilitate reflux in the main pancreatic duct.

International audience

International audience; The gut microbiota produces a wide variety of metabolites, which interact with intestinal cells and contribute to host physiology. The effect of gut commensal bacteria on host protein SUMOylation, an essential ubiquitin-like modification involved in various intestinal functions, remains, however, unknown. Here, we show that short chain fatty acids (SCFAs) and branched chain fatty acids (BCFAs) produced by the gut microbiota increase protein SUMOylation in intestinal cells in a pH-dependent manner. We demonstrate that these metabolites inactivate intestinal deSUMOylases and promote the hyperSUMOylation of nuclear matrix-associated proteins. We further show that BCFAs inhibit the NF-κB pathway, decrease pro-inflammatory cytokine expression, and promote intestinal epithelial integrity. Together, our results reveal that fatty acids produced by gut commensal bacteria regulate intestinal physiology by modulating SUMOylation and illustrate a new mechanism of dampening of host inflammatory responses triggered by the gut microbiota.

International audience

International audience; Introduction: The risk of inflammatory bowel disease-associated colorectal cancer (IBD-CRC) is known to increase with primary sclerosing cholangitis (PSC) and a family history of CRC. However, the impact of comorbidities such as liver disease, obesity, diabetes, chronic lung, heart, and renal disease, and psychiatric illness on the risk of IBD-CRC remains unclear. We evaluated the effect of these comorbidities on the risk of IBD-CRC.Methods: A retrospective review from 2009 to 2014 was conducted using the National Inpatient Sample data for adults 18 years and older. Patients with IBD (360,892), of whom 2,831 had CRC were identified using the International Classification of Diseases, Ninth Revision codes (ICD-9). Data on comorbidities were also obtained. Adjusted odds ratios (aOR) and confidence intervals (CI) were computed via logistic regression to evaluate the effect of comorbidities on the risk of IBD-CRC; the p-value was set at

International audience; Rationale: Despite clinical-proven benefits of immune checkpoint inhibitors (ICIs) on advanced lung cancer, rare but life-threatening immune-related adverse events (irAEs) have been reported. Pancreatitis is a rare irAE that can occur with any ICI.Patient concerns: A 53-year-old man with locally advanced non–small cell lung carcinoma was treated with radiochemotherapy and then durvalumab (anti–programmed cell death ligand 1 therapy). Twelve weeks after the beginning of ICI, he reported abdominal pain and anorexia. Blood test showed high level of lipase. Abdominal computed tomography revealed a swollen pancreas. These findings were confirmed by magnetic resonance cholangiopancreatography and biliopancreatic endoscopic ultrasonography.Diagnoses: Grade IV immune-related pancreatitis.Interventions: The patient was treated with corticosteroid therapy, resulting in clinical, radiological, and biological improvement.Outcomes: During the first month, corticosteroid therapy could not be decreased under 1 mg/kg/d because of symptoms recurrence and lipasemia rerising. Four months after this episode, the patient died from acute ischemia of the lower limbs while he was on

Background: This prospective multicentre pilot study of patients scheduled for elective major abdominal surgery aimed to validate the fluid challenge (FC) proposed by the closed-loop (CL) system via anaesthesiologist assessment. Methods: This was a phase II trial consisting of two inclusion stages (SIMON method). Each FC (250 mL saline solution for 10 min) proposed by the CL was systematically validated by the anaesthesiologist who could either confirm or refuse the FC or give FC without the CL system. A ≥ 95% agreement between the CL and the anaesthesiologist was considered acceptable. Results: The study was interrupted after interim analysis of the first 19 patients (10 men, median age = 61 years, median body mass index = 26 kg/m2). The anaesthesiologists accepted 165/205 (80%) of fluid boluses proposed by the CL. Median cardiac index (CI) was 2.9 (interquartile: IQ (2.7; 3.4) L/min/m2) and the median coefficient of variation (CV) for CI was 13% (10; 17). Fifteen out of nineteen patients (79%) had a mean CI > 2.5 L/min/m2 or spent > 85% surgery time with pulse pressure variation < 13%. No adverse events related to the CL were reported. Conclusion: In this study of patients scheduled for elective major abdominal surgery, the agreement between CL and anaesthesiologist for giving fluid challenge was 80%, suggesting that CL cannot replace the physician but could help in decision making.