Pathogenesis Of Liver Fibrosis Research Articles

Mathematical model of liver cirrhosis formation during morphological and molecular-genetic preclinical studies

BACKGROUND: Currently, researchers describe challenges in developing new treatments for fibrosis and cirrhosis: poor quality of preclinical models, insufficient trial duration, and lack of markers of therapeutic response. A separate task is to standardize the process of liver cirrhosis formation in preclinical trials, which is necessary to obtain accurate quantitative estimates in a short timeframe. AIM: This study aimed to develop a mathematical model for the formation of liver cirrhosis during preclinical trials. MATERIALS AND METHODS: Liver fibrosis and cirrhosis were induced in male Wistar rats using freshly prepared thioacetamide solution for 17 weeks. The area of connective tissue was determined as a percentage of the image area. The area of interlobular veins was measured in µm2. The numbers of cells expressing the FAP marker and the α-SMA marker were counted. The level of mRNA expression of the Vegfa and Yap1 genes was assessed by real-time polymerase chain reaction. A mathematical model for classifying observations into stages was constructed using multiple logistic regression with stepwise selection of predictors, followed by calculation of sensitivity, specificity, and area under the curve with a 95% confidence interval based on ROC analysis. RESULTS: As a result of the analysis, a mathematical model of liver cirrhosis formation was developed. The model is based on the values of two indicators: FAP+ cells and Yap1 mRNA and demonstrated good quality. The resulting value of the area under the ROC curve of 0.883 suggests good results for classifying cases. CONCLUSIONS: The mathematical model makes it possible to differentiate the stage of liver cirrhosis from the stage of fibrosis during preclinical studies. It provides a foundation for studying the pathogenesis of liver fibrosis and cirrhosis, identifying new potential molecular targets for antifibrotic therapy, and reducing the number of expensive, labor-intensive laboratory tests.

Longitudinal evaluation of liver stiffness reveals hepatic cholesterol as the determinant of fibrosis progression in mice

AimsThe metabolic dysfunction-associated steatotic liver disease (MASLD) affects approximately 30 % of the global population. While excessive consumption of dietary fat induces steatosis, it does not develop fibrosis, indicating that additional factors are required as “second hits” for further progression of MASLD. Here, based on shear wave elastography, we compared the longitudinal patterns of fibrogenesis induced by different diets and show the crucial role of cholesterol accumulation in fibrosis progression. Materials and methodsMice were fed chow, high-fat (HFD), high-fat high-cholesterol (HFHCD), choline-deficient, L-amino acid-defined high-fat (CDAHFD), or 3,5-Diethoxycarbonyl-1,4-Dihydrocollidine diets over 12 weeks. Key findingsMice fed with HFD gained significant amounts of body weight but did not show an increase in liver stiffness. In contrast, the addition of cholesterol in the same diet robustly induced liver stiffening starting from the first week, which was comparable to the CDAHFD-induced fibrosis model. Longitudinal tracking of liver stiffness revealed a two-step progression of fibrosis after prolonged feeding of HFHCD and CDAHFD, likely due to cellular cholesterol accumulation over a certain threshold after the transition point. Biochemical analyses suggested the critical role of both total and hepatic cholesterol accumulation in liver fibrosis development. SignificanceCollectively, our results underscore the significance of cholesterol in liver fibrosis development, also highlighting the benefit of monitoring liver stiffness to understand the pathogenesis of liver fibrosis.

In-Depth Proteomic Analysis Reveals Phenotypic Diversity of Macrophages in Liver Fibrosis.

Macrophages make up a heterogeneous population of immune cells that exhibit diverse phenotypes and functions in health and disease. Although macrophage epigenomic and transcriptomic profiles have been reported, the proteomes of distinct macrophage populations under various pathological conditions remain largely elusive. Here, we employed a label-free proteomic approach to characterize the diversity of the hepatic macrophage pool in an experimental model of CCl4-induced liver fibrosis. We found a decrease in the proportion of liver resident embryo-derived KCs (EmKCs), and a drastic increase in the proportion of monocyte-derived KCs (MoKCs) and CLEC2-Macs. Proteomic profiling revealed that MoKCs largely resembled EmKCs, whereas CLEC2-Macs exhibited greater proteomic alternations compared with EmKCs, suggesting two distinct destinations for monocyte differentiation during liver fibrosis. Furthermore, CLEC2-Macs were characterized by increased expression of proteins associated with inflammatory response, antigen processing and presentation processes, which may be involved in the pathogenesis of liver fibrosis. Collectively, our study provides insights into the considerable heterogeneity within the hepatic macrophage pool during liver fibrosis.

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.

Wedelolactone Attenuates Liver Fibrosis and Hepatic Stellate Cell Activation by Suppressing the Hippo Pathway.

Liver fibrosis is a commonly observed pathological phenomenon that occurs during the progression of various types of chronic liver diseases. The Hippo pathway is closely associated with the pathogenesis of liver fibrosis. Previous studies have shown that wedelolactone (WED) has a significant antihepatic fibrosis effect, whereas the target and mechanism underlying WED remain elusive. In this study, we found that WED significantly alleviated liver fibrosis and injury by inhibiting the expression of Yes-associated protein (YAP) and tafazzin (TAZ). In an in vitro model, WED suppressed the activation of hepatic stellate cells (HSCs) induced by transforming growth factor (TGF-β1), as well as the mRNA and protein expression of α-smooth muscle actin (α-SMA), YAP, and TAZ. The allosteric regulation of YAP by WED was confirmed using MD and cellular thermal shift assay. Moreover, specific knockdown or inhibition of YAP did not enhance the suppressive effect of WED on HSC activation or protein expression associated with fibrosis. These findings demonstrated that the administration of WED effectively alleviated liver fibrosis by suppressing the Hippo/YAP/TAZ pathways. In addition, YAP activity may be regulated by WED via allosteric regulation.

Evaluation of Gremlin-1 as a therapeutic target in metabolic dysfunction-associated steatohepatitis

Gremlin-1 has been implicated in liver fibrosis in metabolic dysfunction-associated steatohepatitis (MASH) via inhibition of bone morphogenetic protein (BMP) signalling and has thereby been identified as a potential therapeutic target. Using rat in vivo and human in vitro and ex vivo model systems of MASH fibrosis, we show that neutralisation of Gremlin-1 activity with monoclonal therapeutic antibodies does not reduce liver inflammation or liver fibrosis. Still, Gremlin-1 was upregulated in human and rat MASH fibrosis, but expression was restricted to a small subpopulation of COL3A1/THY1+ myofibroblasts. Lentiviral overexpression of Gremlin-1 in LX-2 cells and primary hepatic stellate cells led to changes in BMP-related gene expression, which did not translate to increased fibrogenesis. Furthermore, we show that Gremlin-1 binds to heparin with high affinity, which prevents Gremlin-1 from entering systemic circulation, prohibiting Gremlin-1-mediated organ crosstalk. Overall, our findings suggest a redundant role for Gremlin-1 in the pathogenesis of liver fibrosis, which is unamenable to therapeutic targeting.

Evaluation of Gremlin-1 as a therapeutic target in metabolic dysfunction-associated steatohepatitis.

Gremlin-1 has been implicated in liver fibrosis in metabolic dysfunction-associated steatohepatitis (MASH) via inhibition of bone morphogenetic protein (BMP) signalling and has thereby been identified as a potential therapeutic target. Using rat in vivo and human in vitro and ex vivo model systems of MASH fibrosis, we show that neutralisation of Gremlin-1 activity with monoclonal therapeutic antibodies does not reduce liver inflammation or liver fibrosis. Still, Gremlin-1 was upregulated in human and rat MASH fibrosis, but expression was restricted to a small subpopulation of COL3A1/THY1+ myofibroblasts. Lentiviral overexpression of Gremlin-1 in LX-2 cells and primary hepatic stellate cells led to changes in BMP-related gene expression, which did not translate to increased fibrogenesis. Furthermore, we show that Gremlin-1 binds to heparin with high affinity, which prevents Gremlin-1 from entering systemic circulation, prohibiting Gremlin-1-mediated organ crosstalk. Overall, our findings suggest a redundant role for Gremlin-1 in the pathogenesis of liver fibrosis, which is unamenable to therapeutic targeting.

Wharton's Jelly mesenchymal stem cell-derived extracellular vesicles induce liver fibrosis-resolving phenotype in alternatively activated macrophages.

The potential of extracellular vesicles (EVs) isolated from mesenchymal stromal cells in guiding macrophages toward anti-inflammatory immunophenotypes, has been reported in several studies. In our study, we provided experimental evidence of a distinctive effect played by Wharton Jelly mesenchymal stromal cell-derived EVs (WJ-EVs) on human macrophages. We particularly analyzed their anti-inflammatory effects on macrophages by evaluating their interactions with stellate cells, and their protective role in liver fibrosis. A three-step gradient method was used to isolate monocytes from umbilical cord blood (UCB). Two subpopulations of WJ-EVs were isolated by high-speed (20,000 g) and differential ultracentrifugation (110,000 g). Further to their characterization, they were designated as EV20K and EV110K and incubated at different concentrations with UCB-derived monocytes for 7 days. Their anti-fibrotic effect was assessed by studying the differentiation and functional levels of generated macrophages and their potential to modulate the survival and activity of LX2 stellate cells. The EV20K triggers the polarization of UCB-derived monocytes towards a peculiar M2-like functional phenotype more effectively than the M-CSF positive control. The EV20K treated macrophages were characterized by a higher expression of scavenger receptors, increased phagocytic capacity and production level of interleukin-10 and transforming growth factor-β. Conditioned medium from those polarized macrophages attenuated the proliferation, contractility and activation of LX2 stellate cells. Our data show that EV20K derived from WJ-MSCs induces activated macrophages to suppress immune responses and potentially play a protective role in the pathogenesis of liver fibrosis by directly inhibiting HSC's activation.

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.

A Genetically Engineered Biomimetic Nanodecoy for the Treatment of Liver Fibrosis.

Liver fibrosis, arising from factors such as viral infections or metabolic disorders, represents an ongoing global health challenge and is a major risk factor for hepatocellular carcinoma. Unfortunately, there are no clinically approved drugs available for its treatment. Recent studies have illuminated the pivotal role of macrophage recruitment in the pathogenesis of liver fibrosis, presenting a potential therapeutic target. Therefore, it holds great promise to develop novel anti-fibrotic therapies capable of inhibiting this process. Herein, a drug-loaded biomimetic nanodecoy (CNV-C) is developed by harnessing genetically engineered cellular vesicles for the treatment of liver fibrosis. CNV-C is equipped with a C-C motif chemokine receptor 2 (CCR2)-overexpressed surface, enabling it to selectively neutralize elevated levels of C-C motif chemokine ligand 2 (CCL2), thereby reducing macrophage infiltration and the subsequent production of the fibrogenic cytokine transforming growth factor β (TGF-β). Moreover, curcumin, an anti-fibrotic agent, is loaded into CNV-C and delivered to the liver, facilitating its efficacy in suppressing the activation of hepatic stellate cells by blocking the downstream TGF-β/Smad signaling. This combinational therapy ultimately culminates in the alleviation of liver fibrosis in a mouse model induced by carbon tetrachloride. Collectively, the findings provide groundbreaking proof-of-concept for employing genetically modified nanodecoys to manage liver fibrosis, which may usher in a new era of anti-fibrotic treatments.

The possible pathogenesis of liver fibrosis: therapeutic potential of natural polyphenols.

Liver fibrosis is the formation of a fibrous scar resulting from chronic liver injury, independently from etiology. Although many of the mechanical details remain unknown, activation of hepatic stellate cells (HSCs) is a central driver of liver fibrosis. Extracellular mechanisms such as apoptotic bodies, paracrine stimuli, inflammation, and oxidative stress are critical in activating HSCs. The potential for liver fibrosis to reverse after removing the causative agent has heightened interest in developing antifibrotic therapies. Polyphenols, the secondary plant metabolites, have gained attention because of their health-beneficial properties, including well-recognized antioxidant and anti-inflammatory activities, in the setting of liver fibrosis. In this review, we present an overview of the mechanisms underlying liver fibrosis with a specific focus on the activation of resident HSCs. We highlight the therapeutic potential and promising role of natural polyphenols to mitigate liver fibrosis pathogenesis, focusing on HSCs activation. We also discuss the translational gap from preclinical findings to clinical treatments involved in natural polyphenols in liver fibrosis.

PPARβ/δ attenuates hepatic fibrosis by reducing SMAD3 phosphorylation and p300 levels via AMPK in hepatic stellate cells

The role of peroxisome proliferator-activated receptor (PPAR)β/δ in hepatic fibrosis remains a subject of debate. Here, we examined the effects of a PPARβ/δ agonist on the pathogenesis of liver fibrosis and the activation of hepatic stellate cells (HSCs), the main effector cells in liver fibrosis, in response to the pro-fibrotic stimulus transforming growth factor-β (TGF-β). The PPARβ/δ agonist GW501516 completely prevented glucose intolerance and peripheral insulin resistance, blocked the accumulation of collagen in the liver, and attenuated the expression of inflammatory and fibrogenic genes in mice fed a choline-deficient high-fat diet (CD-HFD). The antifibrogenic effect of GW501516 observed in the livers CD-HFD-fed mice could occur through an action on HSCs since primary HSCs isolated from Ppard-/- mice showed increased mRNA levels of the profibrotic gene Col1a1. Moreover, PPARβ/δ activation abrogated TGF-β1-mediated cell migration (an indicator of cell activation) in LX-2 cells (immortalized activated human HSCs). Likewise, GW501516 attenuated the phosphorylation of the main downstream intracellular protein target of TGF-β1, suppressor of mothers against decapentaplegic (SMAD)3, as well as the levels of the SMAD3 co-activator p300 via the activation of AMP-activated protein kinase (AMPK) and the subsequent inhibition of extracellular signal-regulated kinase-1/2 (ERK1/2) in LX-2 cells. Overall, these findings uncover a new mechanism by which the activation of AMPK by a PPARβ/δ agonist reduces TGF-β1-mediated activation of HSCs and fibrosis via the reduction of both SMAD3 phosphorylation and p300 levels.

Noncoding RNA-Mediated Epigenetic Regulation in Hepatic Stellate Cells of Liver Fibrosis.

Liver fibrosis is a significant contributor to liver-related disease mortality on a global scale. Despite this, there remains a dearth of effective therapeutic interventions capable of reversing this condition. Consequently, it is imperative that we gain a comprehensive understanding of the underlying mechanisms driving liver fibrosis. In this regard, the activation of hepatic stellate cells (HSCs) is recognized as a pivotal factor in the development and progression of liver fibrosis. The role of noncoding RNAs (ncRNAs) in epigenetic regulation of HSCs transdifferentiation into myofibroblasts has been established, providing new insights into gene expression changes during HSCs activation. NcRNAs play a crucial role in mediating the epigenetics of HSCs, serving as novel regulators in the pathogenesis of liver fibrosis. As research on epigenetics expands, the connection between ncRNAs involved in HSCs activation and epigenetic mechanisms becomes more evident. These changes in gene regulation have attracted considerable attention from researchers in the field. Furthermore, epigenetics has contributed valuable insights to drug discovery and the identification of therapeutic targets for individuals suffering from liver fibrosis and cirrhosis. As such, this review offers a thorough discussion on the role of ncRNAs in the HSCs activation of liver fibrosis.

Chronic liver disease and fibrosis: A review of emerging biomarkers and therapeutic targets

Chronic liver disease (CLD) and fibrosis represent a significant global health burden, driven by a range of etiologies including viral hepatitis, alcohol abuse, and non-alcoholic fatty liver disease (NAFLD). These conditions often progress to cirrhosis, liver failure, and hepatocellular carcinoma (HCC), underscoring the urgent need for effective diagnostic and therapeutic strategies. Emerging biomarkers and therapeutic targets offer promising avenues for early diagnosis and intervention in CLD and fibrosis. Biomarkers are crucial for the early detection and monitoring of CLD and fibrosis, allowing for timely therapeutic intervention. Serum biomarkers such as liver enzymes (ALT, AST), bilirubin, and platelet count have traditionally been used, but they lack specificity and sensitivity. Recent advances have identified novel biomarkers with improved diagnostic performance. For instance, serum levels of fibrosis markers like hyaluronic acid, procollagen type III N-terminal peptide (P3NP), and tissue inhibitor of metalloproteinases-1 (TIMP-1) have shown potential in assessing liver fibrosis. Additionally, non-invasive imaging techniques such as transient elastography and magnetic resonance elastography provide quantitative measures of liver stiffness, correlating with fibrosis stage. The pathogenesis of liver fibrosis involves complex interactions between hepatocytes, hepatic stellate cells (HSCs), and the extracellular matrix (ECM). HSCs play a central role in fibrogenesis by transforming into myofibroblasts that secrete collagen and other ECM components. Targeting the activation and proliferation of HSCs has emerged as a promising therapeutic strategy. Small molecule inhibitors, such as those targeting the PDGF and TGF-? signaling pathways, have shown efficacy in preclinical models. Furthermore, antifibrotic agents like simtuzumab, an anti-LOXL2 monoclonal antibody, are being evaluated in clinical trials for their potential to halt or reverse fibrosis progression. Another promising approach involves the modulation of the gut-liver axis. Dysbiosis and increased intestinal permeability contribute to liver inflammation and fibrosis. Probiotics, prebiotics, and fecal microbiota transplantation (FMT) are being explored for their potential to restore gut homeostasis and mitigate liver injury. Additionally, the role of the immune system in fibrosis has gained attention, with immune checkpoint inhibitors and anti-inflammatory agents being investigated for their ability to modulate immune responses and reduce fibrosis. Keywords: Chronic Liver Disease, Fibrosis, Biomarkers, Therapeutic Targets.

Engineered SPIONs functionalized with endothelin a receptor antagonist ameliorate liver fibrosis by inhibiting hepatic stellate cell activation

Endothelin-1/endothelin A receptor (ET-1/ETAR) pathway plays an important role in the progression of liver fibrosis by activating hepatic stellate cells (HSCs) - a key cell type involved in the pathogenesis of liver fibrosis. Inactivating HSCs by blocking the ET-1/ETAR pathway using a selective ETAR antagonist (ERA) represents a promising therapeutic approach for liver fibrosis. Unfortunately, small-molecule ERAs possess limited clinical potential due to poor bioavailability, short half-life, and rapid renal clearance. To improve the clinical applicability, we conjugated ERA to superparamagnetic iron-oxide nanoparticles (SPIONs) and investigated the therapeutic efficacy of ERA and ERA-SPIONs in vitro and in vivo and analyzed liver uptake by in vivo and ex vivo magnetic resonance imaging (MRI), HSCs-specific localization, and ET-1/ETAR-pathway antagonism in vivo. In murine and human liver fibrosis/cirrhosis, we observed overexpression of ET-1 and ETAR that correlated with HSC activation, and HSC-specific localization of ETAR. ERA and successfully synthesized ERA-SPIONs demonstrated significant attenuation in TGFβ-induced HSC activation, ECM production, migration, and contractility. In an acute CCl4-induced liver fibrosis mouse model, ERA-SPIONs exhibited higher liver uptake, HSC-specific localization, and ET-1/ETAR pathway antagonism. This resulted in significantly reduced liver-to-body weight ratio, plasma ALT levels, and α-SMA and collagen-I expression, indicating attenuation of liver fibrosis. In conclusion, our study demonstrates that the delivery of ERA using SPIONs enhances the therapeutic efficacy of ERA in vivo. This approach holds promise as a theranostic strategy for the MRI-based diagnosis and treatment of liver fibrosis.

Autophagy in hepatic progenitor cells modulates exosomal miRNAs to inhibit liver fibrosis in schistosomiasis.

Schistosoma infection is one of the major causes of liver fibrosis. Emerging roles of hepatic progenitor cells (HPCs) in the pathogenesis of liver fibrosis have been identified. Nevertheless, the precise mechanism underlying the role of HPCs in liver fibrosis in schistosomiasis remains unclear. This study examined how autophagy in HPCs affects schistosomiasis-induced liver fibrosis by modulating exosomal miRNAs. The activation of HPCs was verified by immunohistochemistry (IHC) and immunofluorescence (IF) staining in fibrotic liver from patients and mice with Schistosoma japonicum infection. By coculturing HPCs with hepatic stellate cells (HSCs) and assessing the autophagy level in HPCs by proteomic analysis and in vitro phenotypic assays, we found that impaired autophagy degradation in these activated HPCs was mediated by lysosomal dysfunction. Blocking autophagy by the autophagy inhibitor chloroquine (CQ) significantly diminished liver fibrosis and granuloma formation in S. japonicum-infected mice. HPC-secreted extracellular vehicles (EVs) were further isolated and studied by miRNA sequencing. miR-1306-3p, miR-493-3p, and miR-34a-5p were identified, and their distribution into EVs was inhibited due to impaired autophagy in HPCs, which contributed to suppressing HSC activation. In conclusion, we showed that the altered autophagy process upon HPC activation may prevent liver fibrosis by modulating exosomal miRNA release and inhibiting HSC activation in schistosomiasis. Targeting the autophagy degradation process may be a therapeutic strategy for liver fibrosis during Schistosoma infection.

Exportin 4 DNA promoter methylation in liver fibrosis.

A role for exportin 4 (XPO4) in the pathogenesis of liver fibrosis was recently identified. We sought to determine changes in hepatic XPO4 promoter methylation levels during liver fibrosis. The quantitative real-time RT-PCR technique was used to quantify the mRNA level of XPO4. Additionally, pyrosequencing was utilized to assess the promoter methylation status of XPO4. The methylation rate of the XPO4 promoter was significantly increased with fibrosis in human and mouse models, while XPO4 mRNA expression negatively correlated with methylation of its promoter. DNA methyltransferases (DNMTs) levels (enzymes that drive DNA methylation) were upregulated in patients with liver fibrosis compared to healthy controls and in hepatic stellate cells upon transforming growth factor beta (TGFβ) stimulation. The DNA methylation inhibitor 5-Aza or specific siRNAs for these DNMTs led to restoration of XPO4 expression. The process of DNA methylation plays a crucial role in the repression of XPO4 transcription in the context of liver fibrosis development.

The antiprotozoal drug nitazoxanide improves experimental liver fibrosis in mice

Nitazoxanide is an FDA-approved antiprotozoal drug. Our previous studies find that nitazoxanide and its metabolite tizoxanide affect AMPK, STAT3, and Smad2/3 signals which are involved in the pathogenesis of liver fibrosis, therefore, in the present study, we examined the effect of nitazoxanide on experimental liver fibrosis and elucidated the potential mechanisms. The in vivo experiment results showed that oral nitazoxanide (75, 100 mg·kg−1) significantly improved CCl4- and bile duct ligation-induced liver fibrosis in mice. Oral nitazoxanide activated the inhibited AMPK and inhibited the activated STAT3 in liver tissues from liver fibrosis mice. The in vitro experiment results showed that nitazoxanide and its metabolite tizoxanide activated AMPK and inhibited STAT3 signals in LX-2 cells (human hepatic stellate cells). Nitazoxanide and tizoxanide inhibited cell proliferation and collagen I expression and secretion of LX-2 cells. Nitazoxanide and tizoxanide inhibited transforming growth factor-β1 (TGF-β1)- and IL-6-induced increases of cell proliferation, collagen I expression and secretion, inhibited TGF-β1- and IL-6-induced STAT3 and Smad2/3 activation in LX-2 cells. In mouse primary hepatic stellate cells, nitazoxanide and tizoxanide also activated AMPK, inhibited STAT3 and Smad2/3 activation, inhibited cell proliferation, collagen I expression and secretion. In conclusion, nitazoxanide inhibits liver fibrosis and the underlying mechanisms involve AMPK activation, and STAT3 and Smad2/3 inhibition.

Modern possibilities for preventing the formation of liver fibrosis in children: the basics of preventive pediatric hepatology

Liver fibrosis is a natural outcome of almost any liver disease with a steady increase in incidence throughout the world. Considering the pathogenesis of liver fibrosis, the doctor-researcher is faced with the fact that the balance of regeneration processes in relation to the process of chronic inflammation is disturbed. The extracellular matrix accumulates in the liver tissue. Although this is a genetically determined process, but modifying factors play an important role in the progression of the disease. Liver fibrosis in its dynamic development leads to liver cirrhosis, hepatocellular carcinoma. Current data indicate the possibility of reversibility of liver fibrosis at any stage. Understanding the molecular mechanisms of the development of the pathological process is a key area of work for scientists involved in the development of antifibrotic therapy. The article discusses modern views on the prevention of the disease and the prospects for influencing the processes of liver fibrosis with an emphasis on childhood.

Paeoniflorin promotes PPARγ expression to suppress HSCs activation by inhibiting EZH2-mediated histone H3K27 trimethylation

BackgroundThe alleviating effect of paeoniflorin (Pae) on liver fibrosis has been established; however, the molecular mechanism and specific target(s) underlying this effect remain elusive. PurposeThis study was to investigate the molecular mechanism underlying the regulatory effect of Pae on hepatic stellate cells (HSCs) activation in liver fibrosis, with a specific focus on the role of Pae in modulating histone methylation modifications. MethodsThe therapeutic effect of Pae was evaluated by establishing in vivo and in vitro models of carbon tetrachloride (CCl4)-induced mice and transforming growth factor β1 (TGF-β1)-induced LX-2 cells, respectively. Molecular docking, surface plasmon resonance (SPR), chromatin immunoprecipitation-quantitative real time PCR (ChIP-qPCR) and other molecular biological methods were used to clarify the molecular mechanism of Pae regulating HSCs activation. ResultsOur study found that Pae inhibited HSCs activation and histone trimethylation modification in liver of CCl4-induced mice and LX-2 cells. We demonstrated that the inhibitory effect of Pae on the activation of HSCs was dependent on peroxisome proliferator-activated receptor γ (PPARγ) expression and enhancer of zeste homolog 2 (EZH2). Mechanistically, Pae directly binded to EZH2 to effectively suppress its enzymatic activity. This attenuation leaded to the suppression of histone H3K27 trimethylation in the PPARγ promoter region, which induced upregulation of PPARγ expression. ConclusionThis investigative not only sheds new light on the precise targets that underlie the remission of hepatic fibrogenesis induced by Pae but also emphasizes the critical significance of EZH2-mediated H3K27 trimethylation in driving the pathogenesis of liver fibrosis.