ABSTRACT: DNA methylation analysis in non-alcoholic fatty liver disease suggests distinct disease-specific and remodeling signatures after bariatric surgery
Project description:Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries. Liver samples from morbidly obese patients (N=45) with all stages of NAFLD and controls (N=18) were analysed by array-based DNA methylation and mRNA expression profiling. NAFLD-specific expression and methylation differences were seen for nine genes coding for key enzymes in intermediate metabolism (including PC, ACLY, PLCG1) and insulin/insulin-like signalling (including IGF1, IGFBP2, PRKCE) and replicated by bisulfite pyrosequening (independent N=39). Transcription factor binding sites at NAFLD-specific CpG sites were >1000-fold enriched for ZNF274, PGC1A and SREBP2. Intra-individual comparison of liver biopsies before and after bariatric surgery showed NAFLD-associated methylation changes to be partially reversible. Post-bariatric and NAFLD-specific methylation signatures were clearly distinct both in gene-ontology and transcription factor binding site analyses, with >400-fold enrichment of NRF1, HSF1 and ESRRA sites. Our findings provide one of the first examples of treatment-induced epigenetic organ remodelling in humans. 73 samples of human liver grouped into C (control=14), H (healthy obese=27), S (steatosis=14) and N (nash=18). This dataset is part of the TransQST collection.
Project description:FLORINASH - The role of intestinal microflora in non-alcoholic fatty liver disease (NAFLD) EU FP7-HEALTH, project number 241913<br>Florinash examined the role on the gut microbiota in NAFLD. Metagenomic, proteomic, metabolomic and transcriptomic data were integrated to give provide a systems biology approach to disease-associated studies. Liver biopsies were obtained from patients undergoing bariatric surgery; one was used to diagnose NAFLD, the other was used to examine the host transcriptome in NAFLD. This dataset is part of the TransQST collection.
Project description:Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries. Liver samples from morbidly obese patients (N=45) with all stages of NAFLD and controls (N=18) were analysed by array-based DNA methylation and mRNA expression profiling. NAFLD-specific expression and methylation differences were seen for nine genes coding for key enzymes in intermediate metabolism (including PC, ACLY, PLCG1) and insulin/insulin-like signalling (including IGF1, IGFBP2, PRKCE) and replicated by bisulfite pyrosequening (independent N=39). Transcription factor binding sites at NAFLD-specific CpG sites were >1000-fold enriched for ZNF274, PGC1A and SREBP2. Intra-individual comparison of liver biopsies before and after bariatric surgery showed NAFLD-associated methylation changes to be partially reversible. Post-bariatric and NAFLD-specific methylation signatures were clearly distinct both in gene-ontology and transcription factor binding site analyses, with >400-fold enrichment of NRF1, HSF1 and ESRRA sites. Our findings provide one of the first examples of treatment-induced epigenetic organ remodelling in humans.
Project description:Introduction: Bariatric surgery has been shown to improve the histopathological findings in patients with obesity and non-alcoholic steatohepatitis, but there are also reports about non-responder or progressive disease after bariatric interventions. Therefore, it is of utmost importance to understand the pathophysiological processes in the liver after bariatric surgery. Material and Methods: In the present study, mice were fed a Western Diet to induce non-alcoholic steatohepatitis and sleeve-gastrectomy (SG), or sham operation was performed. Mice were observed for two or eight weeks after surgery and metabolic assessment was performed throughout the experiment. Histopathology, fluorescence associated cell sorting and proteomic analysis were conducted to evaluate hepatic inflammation, liver metabolism and affected signaling pathways. Results: Weight loss was higher, and metabolism significantly improved after SG. Two weeks after SG major inflammatory and regulatory disturbances in the liver were observed, but these disturbances decreased in the long-term. Conclusion: The rapid weight loss and decrease of hepatic fat after SG lead to a proinflammatory response in the liver in the early phase after surgery, which changes to a more moderate immune response in the long-term. We suggest a preoperative risk stratification and postoperative surveillance depending on the histopathological findings.
Project description:Chronic liver diseases are worldwide on the rise. Due to the rapidly increasing incidence, in particular in Western countries, non-alcoholic fatty liver disease (NAFLD) is gaining importance. As the disease progresses it can develop into hepatocellular carcinoma. Lipid accumulation in hepatocytes has been identified as the characteristic structural change in NAFLD development, but the molecular mechanisms responsible for disease development remained unresolved. Here, we uncover a strong downregulation of the PI3K-AKT pathway and an upregulation of the MAPK pathway in primary hepatocytes from a preclinical model fed with a Western diet (WD). Dynamic pathway modeling of hepatocyte growth factor (HGF) signal transduction combined with global proteomics identifies that an elevated basal MET phosphorylation rate is the main driver of altered signaling leading to increased proliferation of WD-hepatocytes. Model-adaptation to patient-derived hepatocytes reveals a patient-specific variability in basal MET phosphorylation, which correlates with the outcome of patients after liver surgery. Thus, dysregulated basal MET phosphorylation could be an indicator for the health status of the liver and thereby inform on the risk of a patient to suffer from liver failure after surgery.
Project description:Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of liver disease affecting 20-30% of the population in developed countries. NAFLD is strongly associated with abdominal obesity and is recognized as the hepatic manifestation of the metabolic syndrome. In a subgroup of patients with NAFLD inflammation and fibrosis develops, this so-called Non-Alcoholic Steatohepatitis (NASH) may progress to cirrhosis and hepatocellular carcinoma. A multi-hit hypothesis has been proposed in which during the first “hit” fat accumulation occurs in hepatocytes from excessive delivery of fatty acids from adipose tissue, in addition there is an imbalance in lipid synthesis and export. However, the reason why fat accumulation is subsequently followed by inflammation and fibrosis in some patients is poorly understood. We studied the role of gene expression at the transcriptional level using microarray in bariatric patients from whom the liver histology was available. Patients scheduled for bariatric surgery were recruited in Pretoria/South-Africa. At the time of the procedure, tissue samples of the visceral and subcutaneous fat were taken for molecular analysis as well as liver tissue for histology, also full biochemical data was collected. Patients were grouped according histology: group I (<5% steatosis), group II (NAFLD, 30-50% steatosis) and group III (NASH). The 15 samples were used for microarray (nr patients respectively for stages I-II-III: 6-4-5).This dataset is part of the TransQST collection.
Project description:The pathogenesis of non-alcoholic fatty liver disease is not fully understood. Transcriptomic analysis of a large cohort of 318 patients provides evidence of gene perturbations related to inflammation, complement and coagulation pathways, and tissue remodeling in distinct states of NAFLD.
Project description:Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of histological findings, from simple steatosis to steatohepatitis (NASH), the latter presenting a higher risk of cardiovascular and kidney diseases, type 2 diabetes and end-stage liver disease. NAFLD is seen as the hepatic manifestation of the metabolic syndrome and affects up to 70-80% of obese patients. There are currently no approved pharmacological therapies for NASH, thus the only option is lifestyle intervention or bariatric surgery in order to lose weight and to improve insulin resistance. Although surgical intervention has allowed collections of liver biopsies, transcriptomic data from livers are still scarce and especially follow-up data to evaluate the impact of weight loss intervention on the liver. Therefore we studied hepatic transcriptomic data in a large cohort of obese patients assessed for presence of NASH at baseline and 1 year follow-up. Patients visiting the obesity clinic of the Antwerp University Hospital for a problem of being overweight (BMI above 25 to 29.9 kg/m²) or obese (BMI above 30 kg/m²) were prospectively recruited and underwent a hepatic work-up. Patients were excluded from further analysis in case of significant alcohol consumption (>20 g/day), history of bariatric surgery, diagnosis of another liver disease, pre-existing diabetes. Patients who were, however, diagnosed with de novo diabetes at baseline or at follow-up were not excluded. If NAFLD was suspected, liver biopsy was proposed. For patients undergoing bariatric surgery (BS), a liver biopsy was proposed regardless of the criteria. Patients were reassessed after 1 year. Liver biopsy was performed percutaneously (16G Menghini) or peri-operatively (14G Tru-Cut). The different histological features of NAFLD were assessed using the NASH Clinical Research Network (NASH CRN) Scoring System. The presence of NASH was defined according to Chalasani et al. necessitating the combined presence of steatosis, ballooning and lobular inflammation.
Project description:Obesity is a metabolic disease accompanied by lipid metabolism that can cause hyperlipidemia, non-alcoholic fatty liver disease, and artery atherosclerosis. Sleeve gastrectomy (SG) is a type of bariatric surgery that can effectively treat obesity and improve lipid metabolism. However, its specific underlying mechanism remains unclear. Therefore, we herein performed SG, and sham surgery on two groups of diet-induced obese mice. The results showed that compared to the sham group, the SG group displayed a downregulation of deubiquitinase ubiquitin-specific peptidase 20 (USP20). And USP20 could promote lipid accumulation in vitro. Co-immunoprecipitation and mass spectrometry analyses showed that heat-shock protein family A member 2 (HSPA2) potentially acts as a substrate of USP20. HSPA2 was also downregulated in the SG group and could promote lipid accumulation in vitro. Further research showed that USP20 targeted and stabilized HSPA2 via the ubiquitin-proteasome pathway. The downregulation of the USP20-HSPA2 axis in diet-induced obese mice following SG improved lipid dysmetabolism, indicating that USP20-HSPA2 axis was a noninvasive therapeutic treatment to be investigated in the future.
Project description:Mardinoglu2014 - Genome-scale metabolic model
(HMR version 2.0) - human hepatocytes (iHepatocytes2322)
This model is described in the article:
Genome-scale metabolic
modelling of hepatocytes reveals serine deficiency in patients
with non-alcoholic fatty liver disease.
Mardinoglu A, Agren R, Kampf C,
Asplund A, Uhlen M, Nielsen J.
Nat Commun 2014; 5: 3083
Abstract:
Several liver disorders result from perturbations in the
metabolism of hepatocytes, and their underlying mechanisms can
be outlined through the use of genome-scale metabolic models
(GEMs). Here we reconstruct a consensus GEM for hepatocytes,
which we call iHepatocytes2322, that extends previous models by
including an extensive description of lipid metabolism. We
build iHepatocytes2322 using Human Metabolic Reaction 2.0
database and proteomics data in Human Protein Atlas, which
experimentally validates the incorporated reactions. The
reconstruction process enables improved annotation of the
proteomics data using the network centric view of
iHepatocytes2322. We then use iHepatocytes2322 to analyse
transcriptomics data obtained from patients with non-alcoholic
fatty liver disease. We show that blood concentrations of
chondroitin and heparan sulphates are suitable for diagnosing
non-alcoholic steatohepatitis and for the staging of
non-alcoholic fatty liver disease. Furthermore, we observe
serine deficiency in patients with NASH and identify PSPH,
SHMT1 and BCAT1 as potential therapeutic targets for the
treatment of non-alcoholic steatohepatitis.
This model is hosted on
BioModels Database
and identified by:
MODEL1402200003.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.