Project description:Background & Aims: Serum microRNAs (miRNAs) levels are known to change in non-alcoholic fatty liver disease (NAFLD) and may serve as useful biomarkers. This study aimed to profile miRNAs comprehensively at all NAFLD stages. Methods:We profiled 2,083 serum miRNAs in a discovery cohort (183 NAFLD cases representing the complete NAFLD spectrum and 10 population controls). MiRNA libraries generated by HTG EdgeSeq were sequenced by Illumina NextSeq. Selected serum miRNAs were profiled in 372 additional NAFLD cases and 15 population controls by quantitative reverse transcriptase-polymerase chain reaction. Results: Levels of 275 miRNAs differed between cases and population controls. Fewer differences were seen within individual NAFLD stages but miR-193a-5p consistently the showed increased levels in all comparisons. Relative to NAFL/NASH with mild fibrosis (stage 0/1), three miRNAs (miR-193a-5p, miR-378d and miR378d) were increased in cases with NASH and clinically significant fibrosis (stage 2-4), seven (miR193a-5p, miR-378d, miR-378e, miR-320b, c, d & e) increased in cases with NAFLD Activity Score (NAS) 5-8 compared with lower NAS, and three (miR-193a-5p, miR-378d, miR-378e) increased but one (miR-19b-3p) decreased in steatosis, activity, and fibrosis "activity" (SAF-A) score 2-4 compared with lower SAF-A. The significant findings for miR-193a-5p were replicated in the additional NAFLD cohort. Studies in Hep G2 cells showed that following palmitic acid treatment, miR-193a-5p expression decreased significantly. Gene targets for miR-193a-5p were investigated in liver RNAseq data for a case subgroup (n=80); liver GPX8 levels correlated positively with serum miR-193a-5p. Conclusions: Serum miR-193a-5p levels correlate strongly with NAFLD activity grade and fibrosis stage. MiR-193a-5p may have a role in the hepatic response to oxidative stress and is a potential clinically tractable circulating biomarker for progressive NAFLD.
Project description:Liver biopsy is currently the only reliable method to establish non‐alcoholic fatty liver disease (NAFLD) severity. However, this technique is invasive and occasionally associated with severe complications. Thus, non‐invasive diagnostic markers for NAFLD are needed. Former studies have postulated 18 different serum biomarker microRNAs with altered levels in NAFLD patients. In this study, we have re‐examined the predictive value of these serum microRNAs and found that only 6 of them (miR‐34a, ‐192, ‐27b, ‐122, ‐197 and ‐30c) are validated in our independent cohort as biomarkers associated with NAFLD severity. Among them, miR‐192, ‐27b and ‐122 are abundantly expressed in liver and confidently detected in serum, and display strong correlations with transaminases. The classification performance of validated miRNAs (and their ratios) for patients with non‐alcoholic steatohepatitis (NASH) is similar to that reached by AST, whereas for advanced fibrosis prediction, the miR‐27b/‐197 ratio demonstrated a good performance and an excellent sensitivity and, along with the FIB‐4 index, may constitute a potent non‐invasive predictive tool.
Project description:A time course of the effect of overexpressing GPI-PLD on global gene expression in HepG2 cells was compared to control virus. Experiment Overall Design: This experiment compares the global gene expression in HepG2 cells that were either transduced with an adenovirus expressing GPI-phospholipase D or an adenovirus expressing beta galactosidase as a control. Treatment was for 6 or 12 hrs. Four replicates for each condition were used. 10 micrograms of total RNA was assayed per genechip using standard Affymetrix protocols. CONTEXT: Recent studies demonstrated that de novo lipogenesis is increased in patients with nonalcoholic fatty liver disease (NAFLD). Patients with NAFLD also have plasma lipid abnormalities. These lipid abnormalities may in part be related to insulin resistance, which is common in patients with NAFLD. Insulin resistance is associated with alterations in proteins involved in lipid metabolism including glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD), which is involved in triglyceride metabolism. OBJECTIVE: The objective of the study was to determine whether alterations in serum and hepatic levels of GPI-PLD occur in patients with NAFLD. DESIGN AND PATIENTS: We examined the following: 1) levels of serum GPI-PLD in nondiabetics with nonalcoholic steatohepatitis, compared with matched controls; 2) hepatic expression of GPI-PLD mRNA in patients with normal liver or NAFLD; and 3) effect of overexpressing GPI-PLD vs. beta-galactosidase (control) on global gene expression in a human hepatoma cell line. RESULTS: The serum levels of GPI-PLD were significantly higher in patients with nonalcoholic steatohepatitis than in matched controls (119 +/- 24 vs.105 +/- 15 microg/ml, P = 0.047). The hepatic expression of GPI-PLD mRNA was increased nearly 3-fold in NAFLD patients, compared with patients with normal liver (3.1 +/- 2.6 vs. 1.1 +/- 1.0 arbitrary units per microgram total RNA, P = 0.026). Finally, overexpressing GPI-PLD was associated with an increase in de novo lipogenesis genes. CONCLUSIONS: Patients with NAFLD have elevated serum levels and hepatic expression of GPI-PLD, and its overexpression in vitro is associated with increased expression of de novo lipogenesis genes. These results suggest that GPI-PLD may play a role in the pathogenesis of NAFLD and/or its metabolic features and warrants further investigation.
Project description:Background & Aims: Although non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, aspects of its molecular pathogenesis are unknown and clinical biomarkers for early diagnosis and accurate disease staging remain scarce. The aims of these experiments were to identify and characterize liver protein alterations in an animal model of NAFLD and explore the utility of novel candidate biomarkers in NAFLD patients. Methods: Liver protein fractions were analyzed in a relative quantitative proteomic approach utilizing isobaric tags for relative and absolute quantitation (iTRAQ) labeling combined with nano-liquid chromatography and tandem mass spectrometry (nLC-MS/MS). Differential expression was confirmed independently by western blotting and immunohistochemistry, first in mouse sections and then in biopsies from paediatric NAFLD patients. Candidate serum biomarkers were analyzed by enzyme-linked immunosorbent assay in serum from adult NAFLD patients. Results: Through proteomic profiling we identified decreased expression of hepatic glyoxalase 1 (GLO1) in an animal model of NAFLD. GLO1 protein levels were also found reduced in tissue biopsies from pediatric NAFLD patients. In vitro experiments demonstrated that, in response to lipid-loading in hepatocytes, GLO1 is first hyper-acetylated then ubiquitinylated and degraded, leading to an increase in reactive methylglyoxal. In a cohort of 62 biopsy-confirmed adult NAFLD patients serum levels of the primary methylglyoxal-derived advanced glycated endproduct, hydroimidazolone (MG-H1) were found strongly correlated with body mass index (r=0.619, p<0.0001). Conclusions: We characterize, for the first time, the post-translational modification and regulation of GLO1 expression in response to hepatic lipid loading with functional consequences in NAFLD patients.
Project description:Periodontitis increases the risk of non-alcoholic fatty liver disease (NAFLD). However, the precise mechanisms are unclear. Here, gut dysbiosis induced by orally administered Porphyromonas gingivalis, a representative periodontopathic bacterium, was implicated in the deterioration of NAFLD pathology. C57BL/6 mice were administered with the vehicle, P. gingivalis or Prevotella intermedia, with weaker periodontal pathogenicity, followed by feeding on a choline-deficient, high fat diet (CDAHFD60). CDAHFD60 feeding induced hepatic steatosis, and combined bacterial administration further aggravated NAFLD pathology with increased fibrosis. Liver gene expression analyses revealed that genes involved in the NAFLD pathology were perturbed with distinctive expression profiles induced by different bacteria. These differences may be due to quantitative and qualitative differences in the influx of gut bacterial products because the serum endotoxin level, gut microbiota composition, and serum metabolite profile caused by ingested P. intermedia and P. gingivalis were different. These findings provide insights into mechanisms linking periodontitis and NAFLD.
Project description:<p>Nonalcoholic fatty liver disease (NAFLD) is a major public health problem due to the high incidence affecting approximately one-third of the world’s population. NAFLD is usually linked to obesity and excessive weight. A subset of patients with NAFLD express normal or low body mass index; thus, the condition is called nonobese NAFLD or lean NAFLD. However, patients and healthcare professionals have little awareness and understanding of NAFLD in nonobese individuals. Furthermore, preclinical results from nonobese animal models with NAFLD are unclear. Gut microbiota and their metabolites in nonobese/lean NAFLD patients differ from those in obese NAFLD patients. Therefore, we analyzed the biochemical indices, intestinal flora and intestinal metabolites in a nonobese NAFLD mouse model established using a methionine-choline deficient (MCD) diet. The significantly lean MCD mice had a remarkable fatty liver with lower serum triglyceride and free fatty acid levels as well as higher alanine transaminase and aspartate transaminase levels than normal mice. 16s RNA sequencing of fecal DNA showed that the overall richness and diversity of the intestinal flora decreased in MCD mice, whereas the Firmicutes/Bacteroidota ratio was increased. <em>g_Tuzzerella, s_Bifidobacterium pseudolongum</em> and <em>s_Faecalibaculum rodentium</em> were the predominant species in nonobese NAFLD mice. Fecal metabolomics using LC-MS/MS revealed the potential biomarkers for the prognosis and diagnosis of nonobese NAFLD, including high levels of tyramine glucuronide, 9,12,13-TriHOME and pantetheine 4'-phosphate, and low levels of 3-carbamoyl-2-phenylpropionaldehyde, N-succinyl-L,L-2,6-diaminopimelate, 4-methyl-5-thiazoleethanol, homogentisic acid and estriol. Our findings could be useful to identify and develop drugs to treat nonobese NAFLD and lean NAFLD.</p>
Project description:The aim of this discovery case-control study was to identify patterns of differential expression of microRNAs in people living with HIV (PLWH) and assess their diagnostic value for non-alcoholic fatty liver disease (NALFD). Cases were defined as patients with severe NAFLD and controls as patients without NAFLD, characterized using the controlled attenuation parameter (CAP). Cases and controls were matched 1:1 for age, sex, body mass index, CD4+ lymphocyte count, active HCV infection, and ART regimen. Serum 2,083 simultaneous microRNA transcripts were analyzed using HTG technology and compared between cases and controls. Forty-five patients, 23 cases, and 22 controls were included in the study. In the analysis of the expression pattern of the 2,083 microRNAs, no differential expression patterns were found between both groups of patients included in the study. Analysis of the microRNA transcriptome profile of nonobese PLWH with severe NAFLD did not appear to differ from that of patients without NAFLD. Thus, microRNA might not serve as a proper biomarker for predicting severe NALFD in this population.
Project description:With an estimated prevalence of about 30% in western countries non-alcoholic fatty liver disease (NAFLD) is a major public health issue [PMID: 18956290]. NAFLD is associated with the metabolic syndrome of insulin resistance, obesity, glucose intolerance. Although many studies are pointing to an induction of insulin resistance by NAFLD causality between both phenotypes is not fully clarified. Furthermore, mechanisms leading to strongly differing progression of NAFLD have to be elucidated which range from mild steatosis up to severe steatohepatitis. Steatohepatitis might even result in liver cirrhosis and hepatocellular carcinoma. Additional complexity is introduced into the understanding of the disease by recent studies providing evidence for a direct development of carcinoma from steatosis without the formerly assumed intermediary phase of cirrhosis. Here, we investigate liver samples from patients with varying severities of steatosis in an integrative approach employing transcriptomics, serum biomarker profling, metabolomics data and systems biology models. Total RNA obtained from hepatocytes derived from nine obese patients with distinct grades of steatosis. This dataset is part of the TransQST collection.
Project description:The pathological progression of nonalcoholic fatty liver disease (NAFLD) is driven by multiple factors, and nonalcoholic steatohepatitis (NASH) represents its progressive form. In our previous studies, we found that bicyclol had beneficial effects on NAFLD/NASH. Here we aim to investigate the underlying molecular mechanisms of the bicyclol effect on NAFLD/NASH induced by high-fat diet (HFD) feeding. A mice model of NAFLD/NASH induced by HFD-feeding for 8 weeks was used. As a pretreatment, bicyclol (200 mg/kg) was given to mice by oral gavage twice daily. Hematoxylin and eosin (H&E) stains were processed to evaluate hepatic steatosis, and hepatic fibrous hyperplasia was assessed by Masson staining. Biochemistry analyses were used to measure serum aminotransferase, serum lipids, and lipids in liver tissues. Proteomics and bioinformatics analyses were performed to identify the signaling pathways and target proteins. The real-time RT-PCR and Western blot analyses were performed to verify the proteomics data. As a result, bicyclol had a markedly protective effect against NAFLD/NASH by suppressing the increase of serum aminotransferase, hepatic lipid accumulation and alleviating histopathological changes in liver tissues. Proteomics analyses showed that bicyclol remarkably restored major pathways related to immunological responses and metabolic processes altered by HFD feeding. Consistent with our previous results, bicyclol significantly inhibited inflammation and oxidative stress pathway related indexes (SAA1, GSTM1 and RDH11). Furthermore, the beneficial effects of bicyclol were closely associated with the signaling pathways of bile acid metabolism (NPC1, SLCOLA4 and UGT1A1), cytochrome P450-mediated metabolism (CYP2C54, CYP2C70 and CYP3A25), biological processes such as metal ion metabolism (Ceruloplasmin and Metallothionein-1), angiogenesis (ALDH1A1) and immunological responses (IFI204 and IFIT3). These findings suggested that bicyclol is a potential preventive agent for NAFLD/NASH by targeting multiple mechanisms in future clinical investigations.