Plasma and stool metabolomic biomarkers of non-alcoholic fatty liver disease in Argentina

Background: Non-invasive biomarkers are urgently needed to identify patients with non-alcoholic fatty liver disease (NAFLD) at risk of disease progression, particularly in high prevalence areas such as Latin America. In this regard, targeted metabolomics is a powerful technology for discovering new gut microbiome-derived metabolites. Thus, we aimed to identify potential metabolomic biomarkers related to NAFLD stage in Argentina, and to assess their relationship with clinical and host genetic factors. Methods: Adult healthy volunteers (HV) and biopsy-proven simple steatosis (SS) or non-alcoholic steatohepatitis (NASH) patients were recruited. Demographic, clinical and food frequency consumption data, as well as plasma and stool samples were collected. SNP rs738409 (PNPLA3 gene) was determined in all volunteers. HPLC and flow injection analysis with MS/MS in tandem was applied for metabolomic studies using the MxP Quant 500 Kit (Biocrates Life Sciences AG, Austria). Significantly different metabolites among groups were identified with MetaboAnalyst v4.0. Bivariate and multivariate analyses were used to identify variables that were independently related to NAFLD stage. Forward stepwise logistic regression models were constructed to design the best feature combination that could distinguish between study groups. Receiver Operating Characteristic (ROC) curves were used to evaluate models? accuracy.Results: 19 HV, 12 SS and 22 NASH patients were recruited. Diet was similar between groups. The concentration of 33 out of 424 detected metabolites (25 in plasma and 8 in stool) was significantly different among study groups. Levels of triglycerides (TG) were higher among NAFLD patients, whereas levels of phosphatidylcholines (PC) and lysoPC were higher among HV. The PNPLA3 risk genotype for NAFLD and NASH (GG) was related to higher plasma levels of eicosenoic acid FA(20:1) (p<0.001). Plasma metabolites showed a higher accuracy for diagnosis of NAFLD and NASH when compared to stool metabolites (Table 1). Body mass index (BMI) and plasma levels of PC aa C24:0, FA(20:1) and TG(16:1_34:1) showed high accuracy for diagnosis of NAFLD; whereas the best AUROC for discriminating NASH from SS was that of plasma levels of PC aa C24:0 and PC ae C40:1 (Table 1).Conclusions: Gut microbiome-derived metabolomic biomarkers were identified in plasma and stool, but plasma metabolites were better diagnostic biomarkers of NAFLD and NASH in Argentina. Further validation studies are needed.Fil: Mazzini, Flavia Noelia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Hospital Italiano. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional E Ingenieria Biomedica.; ArgentinaFil: Cook, Frank. Novartis Institutes For Biomedical Research; Estados UnidosFil: Gounarides, John. Novartis Institutes For Biomedical Research; Estados UnidosFil: Marciano, Sebastian. Hospital Italiano; ArgentinaFil: Haddad, Leila. Hospital Italiano; ArgentinaFil: Tamaroff, Ana Jesica. Hospital Italiano; ArgentinaFil: Casciato, Paola. Hospital Italiano; ArgentinaFil: Narvaez, Adriana Haydée. Hospital Italiano; ArgentinaFil: Mascardi, María Florencia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Hospital Italiano. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional E Ingenieria Biomedica.; ArgentinaFil: Anders, Margarita. Hospital Alemán; ArgentinaFil: Orozco, Federico. Hospital Alemán; ArgentinaFil: Quiroz, Nicolas. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Hospital Italiano. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional E Ingenieria Biomedica.; ArgentinaFil: Risk, Marcelo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Hospital Italiano. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional E Ingenieria Biomedica.; ArgentinaFil: Gutt, Susana. Hospital Italiano; ArgentinaFil: Gadano, Adrián Carlos. Hospital Italiano; ArgentinaFil: Mendez Garcia, Celia. Hospital Italiano; ArgentinaFil: Marro, Martin. Novartis Institutes For Biomedical Research; Estados UnidosFil: Penas Steinhardt, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Trinks, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional e Ingeniería Biomédica - Hospital Italiano. Instituto de Medicina Traslacional e Ingeniería Biomédica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e Ingeniería Biomédica; ArgentinaThe Liver Meeting Digital ExperienceEstados UnidosAmerican Association for the Study of the Liver Diseas

Genomics and transcriptomics yields a system-level view of the biology of the pathogen Naegleria fowleri

Background The opportunistic pathogen Naegleria fowleri establishes infection in the human brain, killing almost invariably within 2 weeks. The amoeba performs piece-meal ingestion, or trogocytosis, of brain material causing direct tissue damage and massive inflammation. The cellular basis distinguishing N. fowleri from other Naegleria species, which are all non-pathogenic, is not known. Yet, with the geographic range of N. fowleri advancing, potentially due to climate change, understanding how this pathogen invades and kills is both important and timely. Results Here, we report an -omics approach to understanding N. fowleri biology and infection at the system level. We sequenced two new strains of N. fowleri and performed a transcriptomic analysis of low- versus high-pathogenicity N. fowleri cultured in a mouse infection model. Comparative analysis provides an in-depth assessment of encoded protein complement between strains, finding high conservation. Molecular evolutionary analyses of multiple diverse cellular systems demonstrate that the N. fowleri genome encodes a similarly complete cellular repertoire to that found in free-living N. gruberi. From transcriptomics, neither stress responses nor traits conferred from lateral gene transfer are suggested as critical for pathogenicity. By contrast, cellular systems such as proteases, lysosomal machinery, and motility, together with metabolic reprogramming and novel N. fowleri proteins, are all implicated in facilitating pathogenicity within the host. Upregulation in mouse-passaged N. fowleri of genes associated with glutamate metabolism and ammonia transport suggests adaptation to available carbon sources in the central nervous system. Conclusions In-depth analysis of Naegleria genomes and transcriptomes provides a model of cellular systems involved in opportunistic pathogenicity, uncovering new angles to understanding the biology of a rare but highly fatal pathogen.publishedVersio

De novo fatty acid synthesis by Schwann cells is essential for peripheral nervous system myelination

Myelination calls for a remarkable surge in cell metabolism to facilitate lipid and membrane production. Endogenous fatty acid (FA) synthesis represents a potentially critical process in myelinating glia. Using genetically modified mice, we show that Schwann cell (SC) intrinsic activity of the enzyme essential for de novo FA synthesis, fatty acid synthase (FASN), is crucial for precise lipid composition of peripheral nerves and fundamental for the correct onset of myelination and proper myelin growth. Upon FASN depletion in SCs, epineurial adipocytes undergo lipolysis, suggestive of a compensatory role. Mechanistically, we found that a lack of FASN in SCs leads to an impairment of the peroxisome proliferator-activated receptor (PPAR) γ–regulated transcriptional program. In agreement, defects in myelination of FASN-deficient SCs could be ameliorated by treatment with the PPARγ agonist rosiglitazone ex vivo and in vivo. Our results reveal that FASN-driven de novo FA synthesis in SCs is mandatory for myelination and identify lipogenic activation of the PPARγ transcriptional network as a putative downstream functional mediator

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

Pharmacokinetic and pharmacodynamic evaluation of daclatasvir, asunaprevir plus beclabuvir as a fixed-dose co-formulation for the treatment of hepatitis C

Introduction: Many reports have evaluated the clinical efficacy and safety of the fixed-dose all-oral combination of daclatasvir, asunaprevir, and beclabuvir (DCV-TRIO), which was approved in Japan in December 2016 for the treatment of hepatitis C genotype (GT)-1 infection. Areas covered: This article reviews the pharmacodynamic and pharmacokinetic properties of the DCV-TRIO combination. The topics covered include data regarding the drug’s absorption, distribution, metabolism, excretion, and antiviral activity strategies. Its therapeutic efficacy and safety in GT-1 infection from phase 2/3 clinical trials are also discussed. Expert opinion: The ideal regimen for the treatment of Hepatitis C virus infection should be potent, pangenotypic, Ribavirin-free, safe, co-formulated, and affordable. Considering these characteristics, DCV-TRIO is neither pangenotypic nor potent enough against GT-1a, regardless of the presence or absence of cirrhosis. Other potential limitations of this regimen are its dosification (twice-daily), and the fact that since it includes a protease inhibitor, it is contraindicated in decompensated cirrhosis. For these reasons, it has only been approved in Japan, where more than 70% of the patients are infected with GT-1b. However, this co-formulation might still have a place in the treatment of non-cirrhotic patients infected with GT-1b provided that massive access to treatment is facilitated.Fil: Esposito, Isabella. Hospital Italiano. Instituto de Ciencias Básicas y Medicina Experimental; ArgentinaFil: Marciano, Sebastian. Hospital Italiano; ArgentinaFil: Trinks, Julieta. Hospital Italiano. Instituto de Ciencias Básicas y Medicina Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Waiting list registration and liver transplantation rates among patients with autoimmune liver disease: An 11-year trend analysis

Objectives: We aimed to analyze waiting list and liver transplantation trends for autoimmune liver disease in Argentina.Methods: We designed a population-based analysis of waitlisted or liver transplanted patients for autoimmune hepatitis, primary biliary cholangitis or primary sclerosing cholangitis between 2006-2017 in Argentina. Cumulative incidence rates of waiting list registration and liver transplantation were standardized for age and sex using the 2000 WHO standard population. Joinpoint regression analysis was used to identify changes in waiting list and liver transplantation trends.Results: Waiting list registrations for autoimmune hepatitis, primary biliary cholangitis and primary sclerosing cholangitis represented 9.66%, 5.07% and 0.85%.Wait-listing rates for autoimmune hepatitis and primary biliary cholangitis increased significantly between 2006 and 2017, with an annual percentage change of 4.9% (95% CI 0.8 to 9; p=0.01) and 5.5% (95% CI 1 to 10.2; p=0.01) respectively. Patients with autoimmune hepatitis and primary biliary cholangitis aged 40-59 years showed the highest increase in waiting list registration rates. Waiting list registration trends for primary sclerosing cholangitis remained stable: annual percentagechange 1.4% (CI 95% -2.1 to 5; p=0.4). Liver transplantation for autoimmune hepatitis, primary biliary cholangitis and primary sclerosing cholangitis represented 10.69%, 5.99% and 3.64%. Liver transplantation trends remained stable in all autoimmune liver diseases.Conclusion: Increasing trends of waiting list registration of autoimmune hepatitis and primary biliary cholangitis may respond to higher diagnosis and early referral rates to liver transplant units. Nevertheless, the growing waitlisting of patients with autoimmune end-stage liver disease underlines an unmet need for effective therapy.Fil: Dirchwolf, Melisa. Hospital Privado de Rosario; ArgentinaFil: Marciano, Sebastian. Hospital Italiano. Departamento de Medicina.; ArgentinaFil: Giunta, Diego Hernan. Hospital Italiano. Departamento de Medicina.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ruf, Andres E.. Fundación para la Docencia e Investigación de las Enfermedades del Hígado; Argentin

Unexpected high seroprevalence of hepatitis e virus in patients with alcohol-related cirrhosis

Introduction: Little is known about hepatitis E virus (HEV) infection in patients with cirrhosis. The aim of the present study was to describe the frequency of HEV infection and associated risk factors in patients with cirrhosis from Argentina. Materials and methods: We evaluated HEV seroprevalence (IgG anti-HEV) and acute infections (IgM and RNA) in patients with cirrhosis (n = 140) vs. healthy controls (n = 300). Additionally, we compared the same outcomes in individuals with alcohol-related cirrhosis (n = 43) vs. patients with alcohol use disorder (without cirrhosis, n = 72). Results: The overall HEV seroprevalence in the cohort of subjects with cirrhosis was 25% (35/140), compared to 4% in the healthy control group [12/300; OR = 8; (95% CI = 4-15.99); p<0.05]. HEV seropositivity was significantly higher in alcohol-related cirrhosis compared to other causes of cirrhosis [39.5% vs. 12.4%; OR = 4.71; (95% CI = 1.9-11.6); p<0.05] and to healthy controls [OR = 15.7; (95% CI = 6.8-36.4); p = 0.0001]. The HEV seroprevalence in alcoholic-related cirrhosis vs. with alcohol use disorder was 39.5% vs. 12.5% [OR = 4.58; (95% CI = 1.81-11.58); p<0.001]. Conclusion: We found a high seroprevalence of HEV in patients with cirrhosis and in individuals with alcohol use disorder. The simultaneous presence of both factors (cirrhosis + alcohol) showed more association to HEV infection. Larger studies with prospective follow up are needed to further clarify this interaction.Fil: Fantilli, Anabella Clara. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología Dr. J. M. Vanella; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Trinks, Julieta. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Hospital Italiano. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional E Ingenieria Biomedica.; ArgentinaFil: Marciano, Sebastian. Hospital Italiano; ArgentinaFil: Zárate, Raúl Fabián. Hospital Córdoba; ArgentinaFil: Balderramo, Domingo. Instituto Universitario del Hospital Italiano de Buenos Aires; ArgentinaFil: Martínez Wassaf, Maribel G.. LACE Laboratorios; ArgentinaFil: Haddad, Leila. Hospital Italiano; ArgentinaFil: Gadano, Adrián. Hospital Italiano; ArgentinaFil: Debes, José D.. University of Minnesota; Estados UnidosFil: Pisano, María Belén. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología Dr. J. M. Vanella; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Ré, Viviana Elizabeth. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología Dr. J. M. Vanella; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin