Development Of Liver Fibrosis Research Articles

Modulation of Notch signaling pathway in activated hepatic stellate cells does not ameliorate the outcome of liver fibrosis in carbon tetrachloride and DDC-feeding models

BackgroundRecent research suggests a possible role of Notch signaling pathway in development of liver fibrosis, but exact cellular and molecular mechanisms are still not well defined. Methods: We modulated Notch signaling in activated hepatic stellate cells/myofibroblasts using the model of inducible activation or inhibition of Notch signaling selective for αSMA positive cells in murine models of toxic fibrosis induced by CCl4 and cholestatic fibrosis induced by DDC supplemented feeding.ResultsOur results confirm that Notch signaling pathway is activated in both CCL4 and DDC model of liver fibrosis and that αSMA positive myofibroblasts are of activated hepatic stellate cells origin. However, neither the inhibition of canonical Notch signaling (in tamoxifen treated αSMACreER/RBP-Jfl/fl mice) nor its overactivation (in tamoxifen treated αSMACreER/NICD1 mice) changed the degree of liver fibrosis in comparison to the control groups in either of the investigated models. Furthermore, after the withdrawal of the fibrogenic treatment the degree of resolution of fibrosis was similar between the animals with Notch overactivation and controls. In addition to genetic manipulation, we investigated the effect of antibodies against NOTCH1 and NOTCH2 on the development of liver fibrosis. Treatment with antibodies had effects on thymus and spleen respectively, but failed to ameliorate liver fibrosis. In conclusion, our data demonstrate that modulation of Notch activity in activated HSC is not sufficient to change the outcome of liver fibrosis. The results obtained with inhibitory antibodies further demonstrate limitations of targeting Notch 1 and 2 receptors as antifibrotic therapy. Notch pathway remains a potential target for the treatment of liver fibrosis, but future studies should be directed to Notch 3 signaling and/or targeting different populations of cells.

Pathological Microenvironment-Remodeling Nanoparticles to Alleviate Liver Fibrosis: Reversing Hepatocytes-Hepatic Stellate Cells Malignant Crosstalk.

During the onset and malignant development of liver fibrosis, the pernicious interplay between damaged hepatocytes and activated hepatic stellate cells (HSCs) induce a self-perpetuating vicious cycle, deteriorating fibrosis progression and posing a grave threat to public health. The secretions released by damaged hepatocytes and activated HSCs interact through autocrine or paracrine mechanisms, involving multiple signaling pathways. This interaction creates a harsh microenvironment and weakens the therapeutic efficacy of single-cell-centric drugs. Herein, a malignant crosstalk-blocking strategy is prompted to remodel vicious cellular interplay and reverse pathological microenvironment to put an end to liver fibrosis. Collagenases modified, bardoxolone and siTGF-β co-delivered nanoparticles (C-NPs/BT) are designed to penetrate the deposited collagen barriers and further regulate the cellular interactions through upregulating anti-oxidative stress capacity and eliminating the pro-fibrogenic effects of TGF-β. The C-NPs/BT shows successful remodeling of vicious cellular crosstalk and significant disease regression in animal models. This study presents an innovative strategy to modulate cellular interactions for enhanced anti-fibrotic therapy and suggests a promising approach for treating other chronic liver diseases.

Spatial and Single-Cell Transcriptomics Reveals the Regional Division of the Spatial Structure of MASH Fibrosis.

To elucidate the regional distribution of metabolic dysfunction-associated steatohepatitis (MASH) fibrosis within the liver and to identify potential therapeutic targets for MASH fibrosis. Liver sections from healthy controls, patients with simple steatosis and MASH patients were analysed using spatial transcriptomics integrated with single-cell RNA-seq. Spatial transcriptomics analysis of liver tissues revealed that the fibrotic region (Cluster 9) was primarily distributed in lobules, with some fibrosis also found in the surrounding area. Integration of the single-cell-sequencing data set (GSE189175) showed a greater proportion of inflammatory cells (Kupffer cells and T cells) and myofibroblasts in MASH. Six genes, showing high- or low-specific expression in Cluster 9, namely, ADAMTSL2, PTGDS, S100A6, PPP1R1A, ASS1 and G6PC, were identified in combination with pathology. The average expression levels of ADAMTSL2, PTGDS and S100A6 on the pathological HE staining map were positively correlated with the increase in the degree of fibrosis and aligned strongly with the distribution of fibrosis. ADAMTSL2+ myofibroblasts play a role in TNF signalling pathways and in the production of ECM structural components. Pseudotime analysis indicated that in the early stages of MASH, infiltration by T cells and Kupffer cells triggers a significant inflammatory response. Subsequently, this inflammation leads to the activation of hepatic stellate cells (HSCs), transforming them into myofibroblasts and promoting the development of liver fibrosis. This study is the first to characterise lineage-specific changes in gene expression, subpopulation composition, and pseudotime analysis in MASH fibrosis and reveals potential therapeutic targets for this condition.

Role of PNPLA3 in Hepatic Stellate Cells and Hepatic Cellular Crosstalk.

Since its discovery, the patatin-like phospholipase domain containing 3 (PNPLA3) (rs738409 C>G p.I148M) variant has been studied extensively to unravel its molecular function. Although several studies proved a causal relationship between the PNPLA3 I148M variant and MASLD development and particularly fibrosis, the pathological mechanisms promoting this phenotype have not yet been fully clarified. We summarise the latest data regarding the PNPLA3 I148M variant in hepatic stellate cells (HSCs) activation and macrophage biology or the path to inflammation-induced fibrosis. Elegant but contradictory studies have ascribed PNPLA3 a hydrolase or an acyltransferase function. The PNPLA3 I148M results in hepatic lipid accumulation, which predisposes the hepatocyte to lipotoxicity and lipo-apoptosis, producing DAMPs, cytokines and chemokines leading to recruitment and activation of macrophages and HSCs, propagating fibrosis. Recent studies showed that the PNPLA3 I148M variant alters HSCs biology via attenuation of PPARγ, AP-1, LXRα and TGFβ activity and signalling. The advent of refined techniques in isolating HSCs has made PNPLA3's direct role in HSCs for liver fibrosis development more apparent. However, many other mechanisms still need detailed investigations.

Multi-omic analysis identifies the molecular mechanism of hepatocellular carcinoma with cirrhosis

Hepatocellular carcinoma with cirrhosis promotes the advancement of malignancy and the development of fibrosis in normal liver tissues. Understanding the pathological mechanisms underlying the development of HCC with cirrhosis is important for developing effective therapeutic strategies. Herein, the RNA-sequencing (RNA-seq) data and corresponding clinical features of patients with HCC were extracted from The Cancer Genome Atlas (TCGA) database using the University of California Santa Cruz (UCSC) Xena platform. The enrichment degree of hallmarkers for each TCGA-LIHC cohort was quantified by ssGSEA algorithm. Weighted gene co-expression network analysis (WGCNA) revealed two gene module eigengenes (MEs) associated with cirrhosis, namely, MEbrown and MEgreen. Analysis of these modules using AUCell showed that MEbrown had higher enrichment scores in all immune cells, whereas MEgreen had higher enrichment scores in malignant cells. The CellChat package revealed that both immune and malignant cells contributed to the fibrotic activity of myofibroblasts through diverse signaling pathways. Additionally, spatial transcriptomic data showed that hepatocytes, proliferating hepatocytes, macrophages, and myofibroblasts were located in closer proximity in HCC tissues. These cells may potentially participate in the process of stimulating myofibroblast fibrotic activity, which may be related to the development of liver fibrosis. In summary, we made full use of multi-omics data to explore gene networks and cell types that may be involved in the development and progression of cirrhosis in HCC.

Design, Synthesis, and Pharmacological Evaluation of Dual FXR-LIFR Modulators for the Treatment of Liver Fibrosis.

Although multiple approaches have been suggested, treating mild-to-severe fibrosis in the context of metabolic dysfunction associated with liver disease (MASLD) remains a challenging area in drug discovery. Pathogenesis of liver fibrosis is multifactorial, and pathogenic mechanisms are deeply intertwined; thus, it is well accepted that future treatment requires the development of multitarget modulators. Harnessing the 3,4,5-trisubstituted isoxazole scaffold, previously described as a key moiety in Farnesoid X receptor (FXR) agonism, herein we report the discovery of a novel class of hybrid molecules endowed with dual activity toward FXR and the leukemia inhibitory factor receptor (LIFR). Up to 27 new derivatives were designed and synthesized. The pharmacological characterization of this series resulted in the identification of 3a as a potent FXR agonist and LIFR antagonist with excellent ADME properties. In vitro and in vivo characterization identified compound 3a as the first-in-class hybrid LIFR inhibitor and FXR agonist that protects against the development of acute liver fibrosis and inflammation.

Microenvironment-responsive nano-bioconjugated vesicles for the multi-pronged treatment of liver fibrosis

Liver fibrosis represents an inevitable stage of various chronic liver diseases. The activated hepatic stellate cells (aHSCs) are the main drivers for promoting the development of liver fibrosis. Meanwhile, liver macrophages can secrete pro-inflammatory cytokines, thus accelerating the deterioration of the liver. Regulating both aHSCs and the inflammatory microenvironment in the liver simultaneously may be an effective strategy for treating liver fibrosis. A multi-pronged nano-bioconjugated system, HNP-B-aEV, was developed according to the above strategy. Based on cell aggregate-derived extracellular vesicles (aEVs) and hydroxychloroquine (HCQ)-loaded nanoparticles (HNP) modified with retinol, HNP-B-aEV is prepared via a reactive oxygen species (ROS)-responsive boronate linker. In the ROS-rich microenvironment of liver fibrosis, aEVs and HNP are released, eliminating ROS, and targeting aHSCs and macrophages respectively to inhibit the activation of HSCs. Both in vitro and in vivo studies demonstrated that HNP-B-aEV can significantly inhibit the release of inflammatory factors from M1 macrophages, remodeling the microenvironment and preventing the activation of HSCs, offering a multi-pronged treatment for liver fibrosis. This strategy can inhibit the progression of liver fibrosis at its source, providing a new perspective for the clinical treatment of liver fibrosis.

CCCP induces hepatic stellate cell activation and liver fibrogenesis via mitochondrial and lysosomal dysfunction

Hepatic stellate cells (HSCs) are primary cells for development and progression of liver fibrosis. Mitophagy is an essential lysosomal process for mitochondrial homeostasis, which can be activated by carbonyl cyanide m-chlorophenyl hydrazone (CCCP), a representative mitochondrial uncoupler. However, little information is available on the role of CCCP-mediated mitophagy in HSC activation and liver fibrogenesis. In this study, we showed that CCCP treatment in HSCs caused mitochondrial dysfunction proved by decreased mitochondrial membrane potential, mitochondrial DNA, and ATP contents and increased mitochondrial ROS. Moreover, CCCP induced mitophagy and impaired mitophagy flux at the later stage. This blockade of mitophagic flux effect was mediated by suppression of lysosomal activity; CCCP decreased expression of lysosomal markers and cathepsin B activity, and increased lysosomal pH. Intriguingly, CCCP treatment in LX-2 cells or primary HSCs elevated plasminogen activator inhibitor-1 (PAI-1), a typical fibrogenic marker of HSCs which was attenuated by mitochondrial division inhibitor 1, a mitophagy inhibitor. The up-regulation of PAI-1 by CCCP was not due to altered transcriptional activity but lysosomal dysfunction. In vivo acute or sub-chronic treatment of CCCP to mice induced mitophagy and fibrogenesis of liver. Hepatic fibrogenic marker (PAI-1) was incremented with mitophagy markers (parkin and PTEN-induced putative kinase 1) in the livers of CCCP injected mice. Furthermore, we found that 5-aminoimidazole-4-carboxyamide ribonucleoside reversed CCCP-mediated mitophagy and subsequent HSC activation. To conclude, CCCP facilitated HSC activation and hepatic fibrogenesis via mitochondrial dysfunction and lysosomal blockade, implying that attenuation of CCCP-related signaling molecules may contribute to treat liver fibrosis.

8236 Hepatocyte Vitamin D Receptor (VDR) Regulates Liver Regeneration

Abstract Disclosure: J.E. Gunton: None. Harendran Elangovan [1], Rebecca A. Stokes [1], Jeremy Keane [1], Sarinder Chahal [1], Caroline Samer [1], Miguel Agoncillo [1], Josephine Yu [1], Jennifer Chen [1], Michael Downes 2, Ronald M. Evans 2, Christopher Liddle [1],2, Jenny E. Gunton [1] [1]Centre for Diabetes, Obesity and Endocrinology, The Westmead Institute for Medical Research, University of Sydney, Westmead, NSW, Australia 2 Salk Institute for Biological Studies, La Jolla, CA. USA Background: Vitamin D signals through the vitamin D receptor (VDR) to induce its end-organ effects. Hepatic stellate cells control development of liver fibrosis in response to stressors and vitamin D signaling decreases fibrogenesis. VDR expression in hepatocytes, however, is low in healthy liver, and the role of VDR in hepatocyte proliferation is unclear. Methods: In these studies, hepatocyte-VDR null mice (hVDR) were used to assess the role of VDR and vitamin D signaling in hepatic regeneration. Mice underwent 2/3 partial hepatectomy and liver regeneration and function were studied. Results: hVDR mice had impaired liver regeneration with impaired hepatocyte proliferation. This was associated with significant differential changes in bile salts. Notably, mice lacking hepatocyte VDR had significant increases in expression of conjugated bile acids after partial hepatectomy, consistent with failure to normalize hepatic function by the 14-day time point tested. CDCA (chenodeoxycholate) is an FXR ligand, which was increased after surgery in controls but not in hVDR mice. FXR signaling is important for hepatocyte proliferation. Real-time PCR of hVDR and control livers showed significant changes in expression of cell cycle genes including cyclins D1 and E1 and cyclin-dependent kinase 2. Gene expression profiling of hepatocytes treated with vitamin D or control showed regulation of groups of genes involved in liver proliferation, hepatitis, liver hyperplasia / hyperproliferation and liver necrosis / cell death. Conclusions: Together these studies demonstrate an important functional role for VDR in hepatocytes during liver regeneration. Combined with the known profibrotic effects of impaired VDR signaling in stellate cells, these studies provide a mechanism whereby vitamin D deficiency would both reduce hepatocyte proliferation and permit fibrosis, leading to significant liver compromise. Presentation: 6/2/2024

Blockade of 11β-hydroxysteroid dehydrogenase type 1 ameliorates metabolic dysfunction-associated steatotic liver disease and fibrosis

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a key enzyme involved in the conversion of cortisone to active cortisol in the liver. Elevated cortisol levels can trigger oxidative stress, inflammation, and hepatocyte damage, highlighting the importance of 11β-HSD1 inhibition as a potential therapeutic approach. This study aimed to explore the effects of INU-101, an inhibitor of 11β-HSD1, on the development of metabolic dysfunction-associated steatotic liver disease (MASLD) and fibrosis. Our findings demonstrated that INU-101 effectively mitigated cortisol-induced lipid accumulation, reactive oxygen species generation, and hepatocyte apoptosis. Furthermore, 11β-HSD1 inhibition suppressed hepatic stellate cell activation by modulating β-catenin and phosphorylated SMAD2/3. INU-101 administration significantly reduced hepatic lipid accumulation and liver fibrosis in mice fed fast-food diet. This study suggests that INU-101 holds promise as a clinical candidate for treating MASLD and fibrosis, offering potential therapeutic benefits by targeting the intricate processes involving 11β-HSD1 and cortisol regulation in the liver.

The association of liver fibrosis and chronic kidney disease in patients with metabolic associated fatty liver disease: A cross-sectional study.

To examine the relation between liver fibrosis and chronic kidney disease (CKD) in metabolic-associated fatty liver disease (MAFLD) patients and its risk factors. The current study was carried out at Tanta University Hospital, Tanta, Egypt, from May 2021 to January 2023 and included 84 MAFLD patients with CKD and 80 MAFLD patients without CKD. All participants had been examined by abdominal ultrasonography and transient elastography with controlled attenuation parameter. Chronic kidney disease patients exhibited a greater incidence of fibrosis compared to patients without CKD (75.6% vs. 24.4%). Logistic analysis demonstrated that the presence of multiple health conditions, such as MAFLD, diabetes mellitus, hypertension, and cardiovascular disease, were individually linked to CKD. Gender and body mass index were not independent factors related to CKD. Additionally, factors such as age, hyperuricemia, hypertriglyceridemia, hypercholesterolemia, hypoalbuminemia, hyperbilirubinemia, and viral hepatitis, apart from MAFLD comorbidities, were independently linked to CKD. Chronic kidney disease may represent a potential risk influence for liver fibrosis development in MAFLD patients.

Serum ECM1 is a promising biomarker for staging and monitoring fibrosis in patients with chronic hepatitis B.

It is critical to assess the extent and progression of liver fibrosis for patients to receive suitable treatments, but its diagnostic methods remain unmet. Extracellular matrix protein 1 (ECM1) has previously been reported to be a key factor in the induction and progression of liver fibrosis. However, little is known about the use of ECM1 as a biomarker to evaluate fibrosis. In a CCl4-induced mouse model of liver fibrosis, the present study demonstrated that ECM1 decreased with gradually increasing fibrosis. Using biopsy as a reference, the serum ECM1 levels decreased with increasing fibrosis stage in 247 patients with liver fibrosis, but there were no significant changes between fibrosis stage 2 and stage 0-1. To improve the performance of ECM1, age, platelet count, and ECM1 concentration were combined to calculate an EPA (ECM1-platelet-age) score (ranging from 0 to 10). The areas under the receiver operating characteristic curve of the EPA scores for the detection of F⩾2, F⩾3, and F4 were 0.6801, 0.7377, and 0.8083, respectively, which showed a comparable or significantly greater diagnostic performance for assessing fibrosis than that of the AST/ALT ratio, APRI score, or FIB-4 score. In HBV patients following antiviral treatment, the dynamics of the EPA score depended on the status of liver fibrosis development. The accuracy of the EPA score in predicting fibrosis regression and progression was 66.00% and 71.43%, respectively, while that of the LSM, another useful method for monitoring hepatic fibrosis changes during treatment, was only 52.00% and 7.14%, respectively. Compared with healthy controls, there were lower levels of serum ECM1 in HBV patients and individuals with HCV infection, MAFLD, ALD, PBC, and DILI. These findings suggested that individuals with reduced ECM1 levels may have a risk of developing liver injury, and further examinations or medical care are needed. In conclusion, the ECM1-containing EPA score is a valuable noninvasive test for staging fibrosis and predicting the progression of liver fibrosis. Additionally, ECM1 alone is an indicator for distinguishing patients with liver injury from healthy controls.

Huangqi Decoction reduces liver fibrosis in rats by modulating PI3K/Akt/mTOR signaling and promoting autophagy.

Liver fibrosis is a chronic condition caused by various factors, and currently, there are no widely effective treatments. Autophagy plays a crucial role in maintaining liver energy homeostasis, and its disruption can contribute to the development of liver fibrosis. This study investigates the effects and molecular mechanisms of Huangqi Decoction, a traditional Chinese medicine, on autophagy and apoptosis in fibrotic liver tissue. Tissue staining indicated that Huangqi Decoction mitigated CCL4-induced liver injury and apoptosis in rats. Western blot analysis of liver fibrosis markers revealed that Huangqi Decoction significantly reduced the expression levels of alpha-smooth muscle actin (α-SMA), type I collagen, matrix metalloproteinase-2 (MMP-2), and matrix metalloproteinase-9 (MMP-9). Additionally, serum markers of liver fibrosis and biochemical indicators of hepatocyte injury showed that Huangqi Decoction effectively lowered serum levels of hyaluronic acid (HA), lymph node (LN), type I collagen, aspartate aminotransferase (AST), and alanine aminotransferase (ALT). Furthermore, Western blot analysis confirmed that Huangqi Decoction alleviated hepatocyte injury by promoting autophagy and inhibiting the PI3K/Akt/mTOR signaling pathway. In conclusion, Huangqi Decoction enhances autophagy and inhibits apoptosis through the PI3K/Akt/mTOR pathway in rats with liver fibrosis.

Signaling pathways that activate hepatic stellate cells during liver fibrosis.

Liver fibrosis is a complex process driven by various factors and is a key feature of chronic liver diseases. Its essence is liver tissue remodeling caused by excessive accumulation of collagen and other extracellular matrix. Activation of hepatic stellate cells (HSCs), which are responsible for collagen production, plays a crucial role in promoting the progression of liver fibrosis. Abnormal expression of signaling pathways, such as the TGF-β/Smads pathway, contributes to HSCs activation. Recent studies have shed light on these pathways, providing valuable insights into the development of liver fibrosis. Here, we will review six signaling pathways such as TGF-β/Smads that have been studied more in recent years.

Dysregulation of sphingolipid metabolism in liver fibrosis

The dysregulation of sphingolipid metabolism emerges as a pivotal factor in the development and progression of liver fibrosis, a condition marked by the overproduction and buildup of extracellular matrix proteins that can lead to liver cirrhosis and failure. Sphingolipids, a diverse class of lipids essential for cellular structure and signaling, are integral to numerous biological functions such as cellular proliferation, morphological differentiation, and programmed cell death. In the context of liver fibrosis, changes in sphingolipid metabolism have been associated with the activation of hepatic stellate cells, the primary cells responsible for fibrogenesis in the liver. These metabolic disruptions lead to an imbalance between profibrotic and antifibrotic sphingolipids, notably sphingosine-1-phosphate and ceramide, contributing to the pathophysiological mechanisms that drive fibrosis. The intricate relationship between sphingolipid metabolism and fibrotic pathways underscores the potential of targeting sphingolipid metabolic enzymes and receptors as therapeutic strategies to mitigate liver fibrosis. The core of this review delves into how disruptions in sphingolipid metabolism contribute to liver fibrosis, exploring biomarkers and potential therapeutic targets. Challenges in research and future directions for comprehensively understanding sphingolipid roles in liver fibrosis are discussed, aiming to open new pathways for therapeutic intervention.

CX3CL1/Fractalkine: A Potential Biomarker for Liver Fibrosis in Chronic HBV Infection.

A hepatitis B virus (HBV) infection can progress to chronic hepatitis, leading to liver fibrosis, cirrhosis, and hepatocellular carcinoma. CX3CL1/Fractalkine plays a crucial role in recruiting immune cells that are responsible for protecting against HBV infection. The aim of this study was to measure CX3CL1/Fractalkine concentrations in the blood plasma of individuals infected with HBV and to evaluate the role of this chemokine in the development of liver tissue fibrosis. Our study included patients infected with HBV, patients infected with HCV, autoimmune hepatitis, and healthy donors. We analyzed the CX3CL1/Fractalkine concentrations in blood plasma using the xMAP technology. Our results showed that HBV-infected patients had lower concentrations of CX3CL1/Fractalkine. Furthermore, in HBV-infected patients with severe fibrosis/cirrhosis, we observed significantly lower concentrations of CX3CL1/Fractalkine compared to those with no/mild fibrosis. Our study revealed that CX3CL1/Fractalkine concentrations are significantly associated with the stage of fibrosis in HBV infection. We demonstrated that lowered CX3CL1/Fractalkine concentrations might have prognostic value for predicting fibrosis development in liver tissue. Our findings suggest that decreased concentrations of CX3CL1/Fractalkine are associated with an increased risk of progressive liver fibrosis, indicating the potential of this chemokine as a prognostic biomarker for the development of liver fibrosis.

The different effects of four adenosine receptors in liver fibrosis.

The adenosine-adenosine receptor pathway plays important roles in the immune system and inflammation. Four adenosine receptors (i.e., A1R, A2AR, A2BR, and A3R) have been identified. However, the roles of these receptors were different in the disease progress and even play opposite roles in the same disease. This study aims to investigate the roles of A1R/A2AR/A2BR/A3R activation in liver fibrosis. Intraperitoneal injection of CCl4 into C57BL/6 mice was used to induce liver fibrosis in the models. Adenosine receptor agonists CCPA, CGS21680, BAY 60-6583, and namodenoson were used for A1R/A2AR/A2BR/A3R activation, respectively. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were used to evaluate the liver function. Hematoxylin and eosin (H&E) staining was used to investigate the pathological damage. Masson staining and Sirius Red staining were performed to evaluate the degree of collagen deposition. CCK8 and scratch assays were used to investigate the proliferation and migration ability of hepatic stellate cells (HSCs). By using liver fibrosis mouse models, we observed that the A1R and A2AR agonists aggravated liver fibrosis, characterized by increasing ALT and AST levels, more serious liver pathological damage, and collagen deposition. However, the A2BR and A3R agonists alleviated liver fibrosis. Moreover, the A1R and A2AR agonist treatment promotes the proliferation and migration of HSC line LX2, while A2BR and A3R agonist treatment inhibited LX2 proliferation and migration. Consistently, A1R and A2AR agonist treatment elevated the expression of α-SMA and Col1α1 in LX2, whereas A2BR and A3R agonist treatment inhibited the expression of α-SMA and Col1α1 in LX2 cells. Additionally, 5'-N-ethyl-carboxamidoadenosine (NECA), a metabolically stable adenosine analog, alleviated liver fibrosis and inhibited LX2 cell activity, proliferation, and migration. This study demonstrated the different roles of A1R/A2AR/A2BR/A3R during liver fibrosis development via regulating the HSC activity and proliferation.

Abstract 14: Arterial Stiffness in Obese Normotensive Children: The First Cardiovascular Risk Biomarker?

Introduction: Obesity is an emerging pandemic driven by consumption of a diet rich in fat, highly refined carbohydrates and a sedentary lifestyle in both children and adults. In obesity arterial stiffness (AS) often associated with endotelial dysfunction (ED) is an independent and strong predictor of cardiovascular disease (CVD) and is a precursor to atherosclerosis, systolic hypertension, cardiac diastolic dysfunction, and impairment of coronary and cerebral flow. In obese children, AS also promotes fatty liver disease whitch eventually leads to fibrosis. Aim of Study: In obese children (OC), central blood pressuere, arterial stiffness and endothelial dysfunction, liver steatosis/fibrosis were evaluated and compared with control group (CG), non-obese, non-hypertensive children. Methods: Carotid-femoral pulse wave velocity (PWV) is the current non-invasive method of choice to asses AS and PWV carotid-brachial variation pre- and post-induced transient ischemia of brachial artery to evaluate ED. Fibroscan (FS) and Control Attenuation Parameter (CAP) are a non-invasive reliable examination that allows to know the degree of liver steatosis and liver stiffness (fibrosis). Carotid-femoral PWV (AS) and PWV variation of brachial artery (ED) were assessed using Complior System® (Artech-Medical France). We evaluated 31 obese children between 10 and 13 years old (BMI 28.70±3.72) and compared to CG (between 11 and 13 years old, n=16, BMI 19.89±1.75) Results: In obese children (BMI 28.70±3.72 and Z score 2.02±0.42) vs CG (BMI 19.89±0.75 and Z core 0.57±0.24), PWV-CF (arterial stiffness) was significantly increased: 5.8±1.3 m/s vs. 3.4±0.9 m/s, p<0.01. PWV-CB variation were paradogical (endothelial dysfunction) after transient ischemia in obese children (△+9% compared to baseline) and it was as epected in the CG (△-12.2% compared to baseline) (P<0.001). Fibroscan and CAP revealed that the degree of steatosis was significantly higher in OC but no differences were found in the degree of liver fibrosis. Conclusions: We found a significatly increase in arterial stiffness in obese children compared to CG. Arterial stiffness in obese children often precedes the development of hypertension and liver fibrosis (even in the presence of liver steatosis) suggesting that arterial stiffness is one of the earliest biomarkers for increased cardiovascular risk. Interventions aimed at attenuating obesity in chidhood are emerging as important target to improve public health outcomes.

A narrative review of genes associated with liver fibrosis in biliary atresia.

Biliary atresia (BA) is characterized by biliary inflammation and obstruction. In the later phase, liver fibrosis occurs. Although the etiology of BA is believed to be multi-factorial, genetic predisposition has been proposed to play a critical role in the pathogenesis. This review aimed to provide an updated summary of the genes that have been reported to be involved in BA-associated liver fibrosis. The review was conducted via evaluation of MalaCards (BA disease: MalaCards-research articles, drugs, genes, clinical trials) which is a universally applied website including various human disease database. The database of genes that are involved in liver fibrosis were studied. Thirty-one genes that are associated with BA according to the disease relevance score were reviewed after further evaluations. Eleven genes (GPT, NR1H4, TGF-B1, MMP7, CCN2, TIMP1, SPP1, ADD3, KRT7, ADD3-AS1, SOX9) that are specific and with a potential association with liver fibrosis were selected for detailed description. Increased expression of GPT, TGF-B1, MMP7, CCN2, TIMP1, SPP1, ADD3, KRT7 and ADD3-AS1 maybe associated with the development of liver fibrosis in BA patients, while the expression of NR1H4 and SOX9 are more likely to suppress liver fibrosis. Current scientific evidence using gene database has revealed a close association between genetic anomalies and the pathogenesis of liver fibrosis in BA. With a better understanding of these anomalies, therapy targeting these related genes may be a new therapeutic approach to alleviate liver fibrosis in BA.

Deacetylation of HnRNP U mediated by sirtuin1 ameliorates aged rat with liver fibrosis via inhibiting p53-related senescence and NLRP3-related inflammation

Senescence represents a major risk factor promoting liver fibrosis progression. Sirtuin 1 (SIRT1), an essential regulator of cellular senescence, may be involved in developing liver fibrosis. However, the role and mechanism of SIRT1 in liver fibrosis development were largely unknown. We constructed the liver fibrosis in aged rats induced by carbon tetrachloride (CCl4) and then transfected with GFP-SIRT1 adenoviral vectors. After that, we performed acetylomic analysis of liver tissue in aged rats to identify potential substrates of SIRT1. Furthermore, replicative senescent rat hepatocytes were pretreated with siRNA HnRNP U, SIRT1 adenoviral vectors, resveratrol, and siRNA SIRT1, following stimulation with H2O2. We found that the protein levels of SIRT1 and HnRNP U were down-regulation in aged rat liver fibrotic tissues, with an accumulation of NLRP3 inflammasome and activation of the p53/p21 pathway in liver tissue, as well as an increased level of plasma IL-1β secretion. In comparison, these effects were reversed by overexpressing SIRT1 with adenoviral vectors. Acetylation of HnRNP U and its sites at K28 and K787 might be potential targets for SIRT1-mediated liver fibrosis in aged rats. Silencing HnRNP U reduced H2O2-induced up-regulation expression of p53, p21, and NLRP3 inflammasome at protein levels. Additionally, H2O2 induced high acetylation of HnRNP U in senescent hepatocytes, whereas overexpressing SIRT1 with adenoviral vectors and resveratrol deacetylate HnRNP U to inhibit NLRP3 inflammasome and the p53/p21 pathway. Besides, the silence of SIRT1 aggravated H2O2-induced p53-related senescence and NLRP3-related inflammation in senescent hepatocytes. Our findings suggested that deacetylation of HnRNPU mediated by SIRT1 attenuated liver fibrosis in the elderly by inhibiting p53/p21 pathway and NLRP3-related inflammation.