SciCombinator

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Concept: Cirrhosis

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A diverse B-cell repertoire is essential for recognition and response to infectious and vaccine antigens. High-throughput sequencing of B-cell receptor (BCR) genes can now be used to study the B-cell repertoire at great depth and may shed more light on B-cell responses than conventional immunological methods. Here, we use high-throughput BCR sequencing to provide novel insight into B-cell dynamics following a primary course of hepatitis B vaccination.

Concepts: Immune system, Protein, Vaccine, Immunology, Biotechnology, Cirrhosis, Hepatitis, Hepatitis B

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Hypertrophic scars (HTS) are characterized by excessive amount of collagen deposition and principally occur following burn injuries or surgeries. In absence of effective treatments, the use of mesenchymal stem/stromal cells, which have been shown to attenuate fibrosis in various applications, seems of interest. The objectives of the present study were therefore to evaluate the effect of human adipose tissue-derived mesenchymal stem cells (hASC) on a pre-existing HTS in a humanized skin graft model in Nude mice and to compare the efficacy of hASCs versus stromal vascular fraction (SVF). We found that injection of SVF or hASCs resulted in an attenuation of HTS as noticed after clinical evaluation of skin thickness, which was associated with lower total collagen contents in the skins of treated mice and a reduced dermis thickness after histological analysis. Although both SVF and hASCs were able to significantly reduce the clinical and histological parameters of HTS, hASCs appeared to be more efficient than SVF. The therapeutic effect of hASCs was attributed to higher expression of TGFβ3 and HGF, which are important anti-fibrotic mediators, and to higher levels of MMP-2 and MMP-2/TIMP-2 ratio, which reflect the remodelling activity responsible for fibrosis resorption. These results demonstrated the therapeutic potential of hASCs for clinical applications of hypertrophic scarring.

Concepts: Scar, Fibrosis, Stem cell, Mesenchymal stem cell, Bone marrow, Effectiveness, Cirrhosis, Skin

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ER stress results in activation of the unfolded protein response and has been implicated in the development of fibrotic diseases. In this study, we show that inhibition of the ER stress-induced IRE1α signaling pathway, using the inhibitor 4μ8C, blocks TGFβ-induced activation of myofibroblasts in vitro, reduces liver and skin fibrosis in vivo, and reverts the fibrotic phenotype of activated myofibroblasts isolated from patients with systemic sclerosis. By using IRE1α(-/-) fibroblasts and expression of IRE1α-mutant proteins lacking endoribonuclease activity, we confirmed that IRE1α plays an important role during myofibroblast activation. IRE1α was shown to cleave miR-150 and thereby to release the suppressive effect that miR-150 exerted on αSMA expression through c-Myb. Inhibition of IRE1α was also demonstrated to block ER expansion through an XBP-1-dependent pathway. Taken together, our results suggest that ER stress could be an important and conserved mechanism in the pathogenesis of fibrosis and that components of the ER stress pathway may be therapeutically relevant for treating patients with fibrotic diseases.

Concepts: Proteins, Protein, Gene, Endoplasmic reticulum, Cirrhosis, Unfolded protein response, Scleroderma, Steven Spielberg

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This study was to evaluate the association between metabolic syndrome (MetS) and chronic virus hepatitis elders in the community. Those subjects with positive hepatitis B surface antigen (HBsAg) and/or anti-hepatitis C virus (anti-HCV) screened in the community before were invited to this study and 451 responded. All participants underwent anthropometric measurements, blood tests, ultrasound and fibroscan examinations. The cut-off of liver stiffness measurement-liver cirrhosis (LSM-LC) was 10 kPa for chronic hepatitis B (CHB) patients and 12 kPa for chronic hepatitis C (CHC) patients, respectively. Among 451 responders, 56 were excluded due to negative HBsAg or anti-HCV. Three hundreds and ninety-five subjects included 228 CHB patients, 156 CHC patients and 11 dual hepatitis patients, had a mean age of 62±12.6 years. Fifty-four (23.7%) CHB patients coexisted with MetS whereas 40 (25.6%) CHC patients also had MetS. Those patients with MetS had more LSM-LC cases than those without (20.4% vs 9.8%, p = 0.04 in CHB patients; 28.2% vs 13.5%, p = 0.037 in CHC patients, respectively). In multivariate logistic analysis, detectable viremia was reversely associated with MetS in CHB patients after adjustment for age, gender and body mass index (odds ratio (OR): 0.42; 95% confidence interval (CI): 0.18-0.99; p = 0.047). Regarding CHC patients, higher LSM level was the only factor contributed to MetS (OR: 1.1; 95% CI: 1.02-1.19; p = 0.012). In conclusion, elder CHB patients coexisted with MetS might experience an inactive virus replication but have an advanced liver fibrosis. In elder CHC patients, only higher LSM level was associated with MetS.

Concepts: Cirrhosis, Hepatitis, Hepatocellular carcinoma, Hepatitis C, Hepatitis B, Hepatitis A, Hepatitis B virus, Hepatitis D

2

The secretin/secretin receptor (SR) axis is upregulated by proliferating cholangiocytes during cholestasis. Secretin stimulates biliary proliferation by downregulation of let-7a and subsequent upregulation of the growth-promoting factor NGF. It is not know if the secretin/SR axis plays a role in subepithelial fibrosis observed during cholestasis. Our aim was to determine the role of secretin/SR axis in the activation of biliary fibrosis in animal models and human primary sclerosing cholangitis (PSC). Studies were performed in Wild-type (WT) mice with bile duct ligation (BDL), BDL SR(-/-) mice or Mdr2(-/-) mouse models of cholestatic liver injury. In selected studies, the SR antagonist (Sec 5-27) was used to block the secretin/SR axis. Biliary proliferation and fibrosis were evaluated as well as the secretion of secretin (by cholangiocytes and S cells), the expression of markers of fibrosis, TGF-β1, TGF-β1R, let-7a and downstream expression of NGF. Correlative studies were performed in human control and PSC liver tissue biopsies, serum and bile. SR antagonist reduced biliary proliferation and hepatic fibrosis in BDL WT and Mdr2(-/-) mice. There was decreased expression of let-7a in BDL and Mdr2(-/-) cholangiocytes that was associated with increased NGF expression. Inhibition of let-7a accelerated liver fibrosis due to cholestasis. There was increased expression of TGF-β1, TGF-β1R. Significantly higher expression of secretin, SR and TGF-β1 was observed in PSC patient liver samples compared to healthy controls. In addition, there was higher expression of fibrosis genes and remarkably decreased expression of let-7a and increased expression of NGF compared to the control.

Concepts: Digestive system, Cirrhosis, Liver, Hepatology, Bilirubin, Bile, Primary biliary cirrhosis, Primary sclerosing cholangitis

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The liver performs a panoply of complex activities coordinating metabolic, immunologic and detoxification processes. Despite the liver’s robustness and unique self-regeneration capacity, viral infection, autoimmune disorders, fatty liver disease, alcohol abuse and drug-induced hepatotoxicity contribute to the increasing prevalence of liver failure. Liver injuries impair the clearance of bile acids from the hepatic portal vein which leads to their spill over into the peripheral circulation where they activate the G-protein-coupled bile acid receptor TGR5 to initiate a variety of hepatoprotective processes.

Concepts: Cholesterol, Immune system, Alcohol, Cirrhosis, Liver, Hepatology, Bile, Hepatic portal vein

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Although it is known that Anderson-Fabry Disease (AFD) can mimic the morphologic manifestations of hypertrophic cardiomyopathy (HCM) on echocardiography, there is a lack of cardiovascular magnetic resonance (CMR) literature on this. There is limited information in the published literature on the distribution of myocardial fibrosis in patients with AFD, with scar reported principally in the basal inferolateral midwall.

Concepts: Diseases and disorders, Myocardial infarction, Scar, Collagen, Fibrosis, Cirrhosis, Hypertrophic cardiomyopathy, Distribution of wealth

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Oral direct-acting antivirals (DAAs) represent a major advance in hepatitis C virus (HCV) treatment. Along with recent updates in HCV screening policy and expansions in insurance coverage, the treatment demand in the United States is changing rapidly. Our objective was to project the characteristics and number of people needing antiviral treatment, and HCV-associated disease burden in the era of oral DAAs. We used a previously developed and validated Hepatitis C Disease Burden Simulation model (HEP-SIM). HEP-SIM simulated the actual clinical management of HCV from 2001 onwards, which included antiviral treatment with peginterferon-based therapies as well as the recent oral DAAs, risk-based and birth-cohort HCV screening, and the impact of the Affordable Care Act. We also simulated two hypothetical scenarios-no treatment and treatment with peginterferon-based therapies only. We estimated that in 2010, 2.5 (95% CI: 1.9-3.1) million non-institutionalized people were viremic, which dropped to 1.9 (95% CI: 1.4-2.6) million in 2015, and projected to drop below 1 million by 2020. A total of 1.8 million HCV patients will receive HCV treatment from the launch of oral DAAs in 2014 until 2030. Based on current HCV management practices, it will take 4-6 years to treat the majority of patients aware of their disease. However, 560,000 patients would still remain unaware by 2020. Even in the oral DAA era, 320,000 patients will die, 157,000 will develop hepatocellular carcinoma, and 203,000 will develop decompensated cirrhosis in the next 35 years.

Concepts: Cancer, United States, Cirrhosis, Hepatitis, Hepatocellular carcinoma, Hepatitis C, Hepatitis B, Hepatitis C virus

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Hepatic encephalopathy (HE) is a clinically significant complication of liver cirrhosis impacting on the patients' quality of life. Minimal hepatic encephalopathy (MHE) is diagnosed by psychometric tests, found in up to 80 % of patients with liver cirrhosis and carries a high risk of progression to overt HE. Continuous therapy with rifaximin in combination with lactulose significantly reduces the risk of overt HE, recurrence of HE and HE-related hospitalizations in randomized, double-blind, placebo-controlled clinical trials. Rifaximin is approved for the therapy of overt HE in Germany. Treatment with lactulose has been shown to improve cognitive functions in patients with liver cirrhosis. Data from prospective clinical trials comparing the efficacy of rifaximin alone against a combination of rifaximin and lactulose in the treatment of MHE are scarce. Changes in the microbiome of the upper and lower gastrointestinal tract as a result of therapy with rifaximin have not yet been addressed in clinical studies.

Concepts: Clinical trial, Cirrhosis, Liver, ClinicalTrials.gov, Gastroenterology, Pharmaceutical industry, Digestion, Hepatic encephalopathy

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Direct induction of induced hepatocytes (iHeps) from fibroblasts holds potential as a strategy for regenerative medicine but until now has only been shown in culture settings. Here, we describe in vivo iHep formation using transcription factor induction and genetic fate tracing in mouse models of chronic liver disease. We show that ectopic expression of the transcription factors FOXA3, GATA4, HNF1A, and HNF4A from a polycistronic lentiviral vector converts mouse myofibroblasts into cells with a hepatocyte phenotype. In vivo expression of the same set of transcription factors from a p75 neurotrophin receptor peptide (p75NTRp)-tagged adenovirus enabled the generation of hepatocyte-like cells from myofibroblasts in fibrotic mouse livers and reduced liver fibrosis. We have therefore been able to convert pro-fibrogenic myofibroblasts in the liver into hepatocyte-like cells with positive functional benefits. This direct in vivo reprogramming approach may open new avenues for the treatment of chronic liver disease.

Concepts: DNA, Gene, Genetics, Cirrhosis, Liver, Transcription factor, Glycogen, Hepatocyte