Role of Oxidative Stress in Hepatic and Extrahepatic Dysfunctions during Nonalcoholic Fatty Liver Disease (NAFLD)

Indexación: Scopus.Nonalcoholic fatty liver disease (NAFLD) is a pathology that contains a broad liver dysfunctions spectrum. These alterations span from noninflammatory isolated steatosis until nonalcoholic steatohepatitis (NASH), a more aggressive form of the disease characterized by steatosis, inflammatory status, and varying liver degrees fibrosis. NAFLD is the most prevalent chronic liver disease worldwide. The causes of NAFLD are diverse and include genetic and environmental factors. The presence of NASH is strongly associated with cirrhosis development and hepatocellular carcinoma, two conditions that require liver transplantation. The liver alterations during NAFLD are well described. Interestingly, this pathological condition also affects other critical tissues and organs, such as skeletal muscle and even the cardiovascular, renal, and nervous systems. Oxidative stress (OS) is a harmful state present in several chronic diseases, such as NAFLD. The purpose of this review is to describe hepatic and extrahepatic dysfunctions in NAFLD. We will also review the influence of OS on the physiopathological events that affect the critical function of the liver and peripheral tissues.https://www.hindawi.com/journals/omcl/2020/1617805/#copyrigh

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Reading macromolecules by translocation through a single nanopore

La translocation de macromolécules au travers d'un nanopore unique est utilisée dans un but de détection et d'identification. Au cours de ces travaux de thèse, un dispositif expérimental, permettant la mesure du courant ionique dans les nanopores de façon optimisée, a été mis en place. Nous avons développé des programmes qui permettent le filtrage du courant mesuré et l'analyse des signaux de translocation. Nous avons fabriqué des nanopores uniques de haut rapport d'aspect avec, un diamètre ajusté au nanomètre près, et à l'état de surface contrôlé, grâce à la combinaison de techniques d'attaque de trace et de dépôt de couches atomiques. A l'aide du dispositif expérimental fabriqué nous avons effectué des mesures de courant ionique dans les nanopores à différentes échelles (autour de 100 nm et en dessous de 10 nm), en utilisant des systèmes différents (solides et hybrides) en présence de macromolécules ou pas. L'interprétation et l'analyse des signaux de courant résultant nous ont permis de mettre en évidence l'importance (i) de l'état de surface du nanopore aussi bien pour le transport des ions au travers du pore que pour leur entrée (ii) et des interactions des ions organisés autour des molécules en translocation avec les ions organisés dans le pore particulièrement lorsque son diamètre est faible (< 10 nm). L'étude de la translocation des polynucléotides au travers d'un nanopore hybride nous a permis de montrer qu'une protéine complexe peut préserver ses propriétés biologiques dans un nanopore solide si son diamètre est proche du diamètre extérieur de la protéine et son état de surface est semblable au milieu dans lequel évolue la protéine.The translocation of macromolecules through a single nanopore is used for purposes of detection and identification. During this thesis, an experimental set-up for ionic current recording in nanopores has been created. We have developed programs that allow filtering of the measured current and signal analysis. We have made high aspect ratio single nanopores with a diameter adjusted at the nanometer scale, and a controlled surface state by using a combination of track-etching and atomic layer deposition techniques. Using the experimental device created we performed measurements of ionic current through the nanopores at different scales (around 100 nm and below 10 nm), using different systems (solid and hybrid) and in the presence of macromolecules or not. The interpretation and analysis of translocation signals allowed us to highlight the importance of (i) the surface state of the nanopore for both the transport of ions through the pore and their entry (ii) and the interactions of the ions organized around the translocating molecule with the ions organized in the nanopore (in particular when the pore diameter is below 10 nm). The study of the translocation of polynucleotides through a hybrid nanopore showed that a complex protein can preserve its biological properties in a solid nanopore if its diameter is close to the outer diameter of the protein and its surface state is similar to the biological environment of the protein

Characterizing PALB2 intragenic duplication breakpoints in a triple-negative breast cancer case using long-read sequencing

IntroductionAccurate identification and characterization of Large Genomic Rearrangements (LGR), especially duplications, are crucial for precise diagnosis and risk assessment. In this report, we characterized an intragenic duplication breakpoint of PALB2 to determine its pathogenicity significance.MethodsA 52-year-old female with triple-negative breast cancer was diagnosed with a novel PALB2 LGR. An efficient and accurate methodology was applied, combining long-read sequencing and transcript analysis for the rapid characterization of the duplication.ResultsDuplication of exons 5 and 6 of PALB2 was validated by transcript analysis. Long-read sequencing enabled the localization of breakpoints within Alu elements, providing insights into the mechanism of duplication via non-allelic homologous recombination.ConclusionUsing our combined methodology, we reclassified the PALB2 duplication as a pathogenic variant. This reclassification suggests a possible causative link between this specific genetic alteration and the aggressive phenotype of the patient

SARS-CoV-2/Renin–angiotensin system: Deciphering the clues for a couple with potentially harmful effects on skeletal muscle

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) has produced significant health emergencies worldwide, resulting in the declaration by the World Health Organization of the coronavirus disease 2019 (COVID-19) pandemic. Acute respiratory syndrome seems to be the most common manifestation of COVID-19. A high proportion of patients require intensive care unit admission and mechanical ventilation (MV) to survive. It has been well established that angiotensin-converting enzyme type 2 (ACE2) is the primary cellular receptor for SARS-CoV-2. ACE2 belongs to the renin-angiotensin system (RAS), composed of several peptides, such as angiotensin II (Ang II) and angiotensin (1-7) (Ang-(1-7)). Both peptides regulate muscle mass and function. It has been described that SARS-CoV-2 infection, by direct and indirect mechanisms, affects a broad range of organ systems. In the skeletal muscle, through unbalanced RAS activity, SARS-CoV-2 could induce severe consequences such as loss of muscle mass, strength, and physical function, which will delay and interfere with the recovery process of patients with COVID-19. This article discusses the relationship between RAS, SARS-CoV-2, skeletal muscle, and the potentially harmful consequences for skeletal muscle in patients currently infected with and recovering from COVID-19.National Fund for Science and Technological Development FONDECYT 1200944 1201039 Millennium Institute on Immunology and Immunotherapy P09-016-F Basal Grant-CEDENNA from The National Research and Development Agency (ANID), Government of Chile AFB180001 Iniciativa Cientifica Milenio (ANID, Chile) Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 120094

Potentiality of Hybrid Biological-artificial Nanopore Based on Biological Channel Confinement

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Determination of the Optimal Bacterial DNA Extraction Method to Explore the Urinary Microbiota

Recent advances in molecular biology have been successfully applied to the exploration of microbiota from various fluids. However, the urinary microbiota remains poorly explored, as its analysis requires specific technical considerations. Indeed, urine is a low microbial biomass environment, in which the representativity of each bacterium must be respected to obtain accurate data. Thus, sensitive extraction methods must be used to obtain good quality DNA while preserving the proportions between species. To address this, we compared the efficiency of five extraction methods on artificial urine samples spiked with low amounts of four bacteria species. The quality of the DNA obtained was further evaluated by different molecular biology approaches, including quantitative PCR and amplicon-based next-generation sequencing (NGS). Although two extraction methods allowed DNA of sufficient quality for NGS analysis to be obtained, one kit extracted a larger amount of DNA, which is more suitable for the detection of low-abundant bacteria. Results from the subsequent assessment of this kit on 29 human clinical samples correlated well with results obtained using conventional bacterial urine culture. We hope that our work will make investigators aware of the importance of challenging and adapting their practice in terms of the molecular biology approaches used for the exploration of microbiota

SingleCellSignalR: inference of intercellular networks from single-cell transcriptomics

International audienceAbstract Single-cell transcriptomics offers unprecedented opportunities to infer the ligand–receptor (LR) interactions underlying cellular networks. We introduce a new, curated LR database and a novel regularized score to perform such inferences. For the first time, we try to assess the confidence in predicted LR interactions and show that our regularized score outperforms other scoring schemes while controlling false positives. SingleCellSignalR is implemented as an open-access R package accessible to entry-level users and available from https://github.com/SCA-IRCM. Analysis results come in a variety of tabular and graphical formats. For instance, we provide a unique network view integrating all the intercellular interactions, and a function relating receptors to expressed intracellular pathways. A detailed comparison of related tools is conducted. Among various examples, we demonstrate SingleCellSignalR on mouse epidermis data and discover an oriented communication structure from external to basal layers

Single nanopore in polymer foil for mass spectrometry

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Ursodeoxycholic acid induces sarcopenia associated with decreased protein synthesis and autophagic flux

Abstract Background Skeletal muscle generates force and movements and maintains posture. Under pathological conditions, muscle fibers suffer an imbalance in protein synthesis/degradation. This event causes muscle mass loss and decreased strength and muscle function, a syndrome known as sarcopenia. Recently, our laboratory described secondary sarcopenia in a chronic cholestatic liver disease (CCLD) mouse model. Interestingly, the administration of ursodeoxycholic acid (UDCA), a hydrophilic bile acid, is an effective therapy for cholestatic hepatic alterations. However, the effect of UDCA on skeletal muscle mass and functionality has never been evaluated, nor the possible involved mechanisms. Methods We assessed the ability of UDCA to generate sarcopenia in C57BL6 mice and develop a sarcopenic-like phenotype in C2C12 myotubes and isolated muscle fibers. In mice, we measured muscle strength by a grip strength test, muscle mass by bioimpedance and mass for specific muscles, and physical function by a treadmill test. We also detected the fiber’s diameter and content of sarcomeric proteins. In C2C12 myotubes and/or isolated muscle fibers, we determined the diameter and troponin I level to validate the cellular effect. Moreover, to evaluate possible mechanisms, we detected puromycin incorporation, p70S6K, and 4EBP1 to evaluate protein synthesis and ULK1, LC3 I, and II protein levels to determine autophagic flux. The mitophagosome-like structures were detected by transmission electron microscopy. Results UDCA induced sarcopenia in healthy mice, evidenced by decreased strength, muscle mass, and physical function, with a decline in the fiber’s diameter and the troponin I protein levels. In the C2C12 myotubes, we observed that UDCA caused a reduction in the diameter and content of MHC, troponin I, puromycin incorporation, and phosphorylated forms of p70S6K and 4EBP1. Further, we detected increased levels of phosphorylated ULK1, the LC3II/LC3I ratio, and the number of mitophagosome-like structures. These data suggest that UDCA induces a sarcopenic-like phenotype with decreased protein synthesis and autophagic flux. Conclusions Our results indicate that UDCA induces sarcopenia in mice and sarcopenic-like features in C2C12 myotubes and/or isolated muscle fibers concomitantly with decreased protein synthesis and alterations in autophagic flux