Hepatic lipopolysaccharide binding protein uncouples inflammation from fibrosis in MAFLD
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE254626 | GEO | 2024/07/15
REPOSITORIES: GEO
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Project description:Metabolic-associated fatty liver disease (MAFLD) comprises a spectrum of clinical entries ranging from benign steatosis to cirrhosis. A key event in the pathophysiology of MAFLD is the development of non-alcoholic steatohepatitis (NASH) that may lead to fibrosis and hepatocellular carcinoma. What triggers inflammation in MAFLD is unknown. We find that lipid accumulation in hepatocytes induces expression of ligands for the activating immune receptor NKG2D. Tissue-resident innate-like T cells are activated through NKG2D and secrete IL-17A. IL-17A licenses hepatocytes to produce chemokines that recruit pro-inflammatory cells into the liver, causing NASH and fibrosis. NKG2D-deficient mice did not develop fibrosis in a dietary model for NASH and had a marked decrease in the incidence of hepatic tumors. Importantly, the frequency of IL-17A+ γδ T cells in the blood MAFLD patients correlated with liver pathology. Our findings identify a key molecular mechanism through which stressed hepatocytes trigger inflammation in context of MAFLD.
2022-04-11 | GSE200482 | GEO
Project description:Understanding mechanisms causing MAFLD (Metabolic Associated Fatty Liver Disease) and its progression to MASH (metabolic dysfunction-associated steatohepatitis) is clinically important and scientifically challenging. Hepatic insulin resistance is a common component in the progression of MAFLD in patients and experimental animals; however, hepatic steatosis caused by the HFD45% (high-fat diet) decreases during chronic hepatic IR generated by inactivation of Irs1/2 (LDKO), AKT1/2, or InsR 1-3—which is inconsistent with the expected relationship between IR and MAFLD in humans4. Here we found that complete hepatic insulin resistance promotes the fructose-enriched GAN diet-induced MAFLD, including acute inflammation and MASH in LDKO mice. Unexpectedly, fructose phosphorylation catalyzed by hepatic Khk (ketohexokinase) was not required as acute MAFLD progressed strongly in LDKOKhkL/L mice fed the GAN diet. FoxO1 activated during hepatic IR induces Fst (Follistatin) expression and secretion from the liver of LDKO mice. Inactivation of hepatic FoxO1 in LTKO mice (LDKO•FoxO1L/L) or Fst in LDKOFstKO mice prevented acute MAFLD during the GAN diet. Consistently, overexpression of hepatic Fst promoted GAN diet-induced MAFLD/MASH and hepatic carcinoma. Mechanistically, circulating Fst promoted adipose tissue IR and lipolysis, which can deliver FFA (free fatty acid) to the liver for esterification with excess Gro3P (glycerol 3-phosphate) generated by fructose metabolism, although hepatic DNL (de novo lipogenesis) decreased strongly in LDKO mice while. Since circulating FST correlates positively with both T2D and MAFLD in humans, our results suggests that hepatic FST induced by progressive hepatic IR might promote MAFLD/MASH during the consumption of sugar-sweetened food and beverages consumed frequently by people and animals with T2D.
2024-06-23 | GSE270246 | GEO
Project description:Okra (Abelmoschus esculentus (L.) Moench) serves as a botanical resource extensively utilized in ethnomedicine. Prior investigations revealed that okra polysaccharide (OP) ameliorated hepatocellular lipotoxicity in vitro context. Nonetheless, the curative efficacy and the precise molecular mechanisms implicated in metabolic-associated fatty liver disease (MAFLD) warrant further elucidation. To address this gap, two murine models of MAFLD, namely obese Ob/Ob mice and high fat/cholesterol/fructose (HFCF) fed mice, were employed. The therapeutic implications of OP supplementation were assessed through quantification of lipid specific biomarkers and hepatic histopathological examination. Complementary transcriptomic, phosphoproteomic, and in vitro analyses were conducted to decipher the molecular underpinnings. In the Ob/Ob mouse model, OP substantively mitigated both circulating and hepatic lipid concentrations, concurrently ameliorating hepatic steatosis. In the context of HFCF-induced MAFLD, OP not only attenuated hepatic lipidic sequestration but also abrogated concomitant inflammation and fibrosis. Subsequent RNA-sequencing analyses on hepatic tissues derived from HFCF-diet mice delineated that OP modulated MAFLD-associated transcriptional signatures. A synergistic assessment of transcriptomics and phosphoproteomics disclosed a salient effect of OP on the Peroxisome Proliferator-Activated Receptor (PPAR) pathway, particularly manifested by the upregulation of PPAR-γ signaling. In murine hepatocytes, OP counteracted steatosis and inflammation via the activation of PPAR-γ signaling. The effects induced by OP were nullified upon administration of the PPAR-γ-specific antagonist GW9662. Collectively, our empirical evidence furnishes the inaugural demonstration that OP mitigates MAFLD pathology through the activation of PPAR-γ signaling, thereby presenting a novel therapeutic avenue for MAFLD intervention.
2024-08-21 | GSE273255 | GEO
Project description:Background & Aims: Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common complication of obesity with a hallmark feature of hepatic steatosis. Recent data from animal models of MALFD have demonstrated substantial changes in macrophage composition in the fatty liver. In humans, the relationship between liver macrophage heterogeneity and liver steatosis is less clear. Methods: Liver tissue from 21 participants was collected at time of bariatric surgery and analyzed using flow cytometry, immunofluorescence, and H&E microscopy. Single-cell RNA sequencing was also conducted on a subset of samples (n=3). Intrahepatic triglyceride content was assessed via MRI and tissue histology. Mouse models of hepatic steatosis were used to investigate observations made from human liver tissue. Results: We observed variable degrees of liver steatosis with minimal fibrosis in our participants. Single-cell RNA sequencing revealed four macrophage clusters that exist in the human fatty liver encompassing Kupffer cells (KC) and monocyte-derived macrophages (MdM). The genes expressed in these macrophage subsets were similar to those observed in mouse models of MAFLD. Hepatic CD14+ monocytes/macrophage number correlated with the degree of steatosis. Using mouse models of early liver steatosis we demonstrate recruitment of MdMs precedes KC loss and liver damage and that MdMs may serve a role in lipid uptake during MAFLD. Conclusions: The human liver in MAFLD contains macrophage subsets that align well with those that appear in mouse models of fatty liver disease. Recruited myeloid cells correlate well with the degree of liver steatosis in humans and this occurs prior to changes in KC number. MdMs appear to have a role in lipid uptake during early stages of MALFD.
2023-10-01 | GSE235079 | GEO
Project description:Background Metabolic associated fatty liver disease (MAFLD) was recently proposed to replace non-alcoholic fatty liver disease (NAFLD), which is defined as ectopic fat deposition in the liver. Hepatic steatosis is an independent predictor for insulin resistance and cardiovascular risk and hence mortality. The aim of present study was to investigate the urine molecular pattern and potential urine biomarker to distinguish healthy control, mild and severe hepatic steatosis in MAFLD patients using proteomic data. Method Hepatic steatosis was measured by Magnetic resonance imaging (MRI) that measure the proton density fat fraction (MRI-PDFF). Proteomic measurements of urine samples were done by mass spectrometry. Linear regression analyses were used to detect significant associations between the biomarkers and clinical parameters. Western blot and Elisa were performed for validation. Results Multiple pathways have been compromised in MAFLD, including the carbohydrate derivative catabolic process, glycosaminoglycan process, aminoglycan metabolic process, inflammatory response, insulin-like growth factor receptor and GTPase complex. Alpha-1-acid glycoprotein 1 (ORM1) and ceruloplasmin were finally identified to be potential urine biomarkers to detect mild/severe hepatic steatosis.
2022-08-12 | PXD026333 | Pride
Project description:Non-alcoholic fatty liver disease (NAFLD) is rapidly becoming the most common liver disease worldwide, yet the pathogenesis of NAFLD is only partially understood. Here, we investigated the role of the gut bacteria in NAFLD by stimulating the gut bacteria via feeding mice the fermentable dietary fiber guar gum and suppressing the gut bacteria via chronic oral administration of antibiotics. Guar gum feeding profoundly altered the gut microbiota composition, in parallel with reduced diet-induced obesity and improved glucose tolerance. Strikingly, despite reducing adipose tissue mass and inflammation, guar gum enhanced hepatic inflammation and fibrosis, concurrent with markedly elevated plasma and hepatic bile acid levels. Consistent with a role of elevated bile acids in the liver phenotype, treatment of mice with taurocholic acid stimulated hepatic inflammation and fibrosis. In contrast to guar gum, chronic oral administration of antibiotics effectively suppressed the gut bacteria, decreased portal secondary bile acid levels, and attenuated hepatic inflammation and fibrosis. Neither guar gum or antibiotics influenced plasma lipopolysaccharide levels. In conclusion, our data indicate a causal link between changes in gut microbiota and hepatic inflammation and fibrosis in a mouse model of NAFLD, possibly via alterations in bile acids.
2017-06-06 | GSE76087 | GEO
Project description:Background and aims: Oxidative stress triggers nonalcoholic steatohepatitis (NASH) and fibrosis. Previous animal studies demonstrated that the transcription factor NRF2, the master regulator of antioxidant response, protects against NASH and fibrosis. S217879, a new generation NRF2 activator has been recently shown to trigger NASH resolution and to reduce established fibrosis in rodents. Our aim was to evaluate the therapeutic potential of S217879 in human metabolic associated fatty liver disease (MAFLD) and its underlying mechanisms using the relevant experimental 3D model of patient-derived precision cut liver slices (PCLS). Methods: We treated PCLS from 12 patients with MAFLD with S217879 or Elafibranor (PPARα/δ agonist used as a referent molecule) for two days. Safety and efficacy profiles, steatosis, liver injury, inflammation and fibrosis were assessed as well as mechanisms involved in NASH pathophysiology, namely antioxidant response, autophagy and ER-stress. Results: Neither Elafibranor nor S217879 had toxic effects at the tested concentrations on human PCLS with MAFLD. PPARα/δ and NRF2 target genes (PDK4, FGF21 and NQO1, HMOX1, respectively) were strongly upregulated in PCLS in response to Elafibranor and S217879, respectively. Compared to untreated PCLS, Elafibranor and S217879-treated slices displayed lower triglycerides and reduced inflammation (IL-1β, IL-6, CCL2). Additional inflammatory markers (CCL5, STING, ICAM-1, VCAM-1) were downregulated by S217879. S217879 but not Elafibranor lowered DNA damages (p-H2A.X, RAD51, XRCC1) and apoptosis (cleaved Caspase-3), and inhibited fibrogenesis markers expression (α-SMA, COL1A1, COL1A2). Such effects were mediated through an improvement of lipid metabolism, activated antioxidant response and enhanced autophagic flux, without effect on ER-stress. Conclusion: This study highlights the therapeutic potential of a new NRF2 activator for NASH using patient-derived PCLS supporting the evaluation of NRF2 activating strategies in clinical trials.
2024-06-07 | GSE234415 | GEO
Project description:The goal of this project was to determine how AhR activity in hepatocytes and HSCs impact liver fibrosis by studying mice with AhR-deficient hepatocytes (AhRΔHep) or AhR-deficient HSCs (AhRΔHSC) during TCDD-induced liver fibrosis as measured by evidence of steatosis, inflammation, HSC activation, and collagen deposition. Overall, our studies indicate that chronic TCDD exposure increases AhR signaling in hepatocytes that result in indirect HSC activation and the development of liver steatosis, whereas hepatic inflammation do not appear to play a major role.
2023-11-01 | GSE200710 | GEO
Project description:Aim: Hepatic fibrosis is a major worldwide medical problem and can develop into liver cirrhosis and hepatocellular carcinoma(HCC). Until now, there are no effective drugs for liver ?brosis because the molecular mechanism of progression of liver fibrosis is not fully understood. MicroRNAs (miRNAs) are an important class of small non-coding functional RNAs that play a key role in many biological processes. The purpose of this study was to clarify how the aberrant expression of miRNAs participates in development of the liver fibrosis in rat liver fibrosis model. Methods: Fibrotic and paired normal liver tissues were collected and assesssed by deep sequencing technology. MiRNA pro?ling results were validated by quantitative real-time polymerase chain reaction (qRT-PCR) and bioinformatics was used to predict miRNA targets. Results: Nine deregulated miRNAs were induced in porcine serum (PS)-induced hepatic fibrosis versus normal liver. Further analysis revealed several signaling pathways (e.g., gap junction and neuroactive ligand-receptor interaction) may be associated with hepatic fibrogenesis. Conclusion: Several miRNAs are dysregulated in PS-induced hepatic fibrosis and seem to be closely associated with hepatic fibrogenesis. These results provide an experimental basis for understanding the mechanism of hepatic fibrosis. We sequenced two samples, including case and control. Each sample has two replicates.
2015-06-04 | E-GEOD-54028 | biostudies-arrayexpress
Project description:The experiment was to identify gene expression changes in mouse liver macrophages upon resolution from inflammation.<br>Macrophages were isolated from mouse livers 24 hours (inflammation) and 72 hours (resolution) following injury (hepatic fibrosis).<br>RNAs were prepared and hybrised on Affymetrix Mouse Genome 1.0 ST arrays.
2011-07-01 | E-MEXP-3177 | biostudies-arrayexpress