Carthamus tinctorius L. inhibits hepatic fibrosis and hepatic stellate cell activation by targeting the PI3K/Akt/mTOR pathway.

Hepatic fibrosis (HF) is a process that occurs during the progression of several chronic liver diseases, for which there is a lack of effective treatment options. Carthamus tinctorius L. (CTL) is often used in Chinese or Mongolian medicine to treat liver diseases. However, its mechanism of action remains unclear. In the present study, CTL was used to treat rats with CCl4­induced HF. The histopathological, biochemical and HF markers of the livers of the rats were analyzed, and CTL­infused serum was used to treat hepatic stellate cells (HSCs) in order to detect the relevant markers of HSC activation. Protein expression pathways were detected both in vitro and in vivo. Histopathological results showed that CTL significantly improved CCl4­induced liver injury, reduced aspartate aminotransferase and alanine aminotransferase levels, promoted E­cadherin expression, and decreased α­smooth muscle actin (SMA), SOX9, collagen I and hydroxyproline expression. Moreover, CTL­infused serum was found to decrease α­SMA and collagen I expression in HSCs. Further studies showed that CTL inhibited the activity of the PI3K/Akt/mTOR pathway in the rat livers. Following the administration of the PI3K agonist 740Y­P to HSCs, the inhibitory effect of CTL on the PI3K/Akt//mTOR pathway was blocked. These results suggested that CTL can inhibit HF and HSC activation by inhibiting the PI3K/Akt/mTOR pathway.

Inhibition of heme-thiolate monooxygenase CYP1B1 prevents hepatic stellate cell activation and liver fibrosis by accumulating trehalose.

Activation of extracellular matrix-producing hepatic stellate cells (HSCs) is a key event in liver fibrogenesis. We showed that the expression of the heme-thiolate monooxygenase cytochrome P450 1B1 (CYP1B1) was elevated in human and mouse fibrotic livers and activated HSCs. Systemic or HSC-specific ablation and pharmacological inhibition of CYP1B1 attenuated HSC activation and protected male but not female mice from thioacetamide (TAA)-, carbon tetrachloride (CCl4)-, or bile duct ligation (BDL)-induced liver fibrosis. Metabolomic analysis revealed an increase in the disaccharide trehalose in CYP1B1-deficient HSCs resulting from intestinal suppression of the trehalose-metabolizing enzyme trehalase, whose gene we found to be a target of RARα. Trehalose or its hydrolysis-resistant derivative lactotrehalose exhibited potent antifibrotic activity in vitro and in vivo by functioning as an HSC-specific autophagy inhibitor, which may account for the antifibrotic effect of CYP1B1 inhibition. Our study thus reveals an endobiotic function of CYP1B1 in liver fibrosis in males, mediated by liver-intestine cross-talk and trehalose. At the translational level, pharmacological inhibition of CYP1B1 or the use of trehalose/lactotrehalose may represent therapeutic strategies for liver fibrosis.

Exogenous S1P via S1P receptor 2 induces CTGF expression through Src-RhoA-ROCK-YAP pathway in hepatic stellate cells.

BACKGROUND: Hepatic fibrosis, a prevalent chronic liver condition, involves excessive extracellular matrix production associated with aberrant wound healing. Hepatic stellate cells (HSCs) play a pivotal role in liver fibrosis, activated by inflammatory factors such as sphingosine 1-phosphate (S1P). Despite S1P's involvement in fibrosis, its specific role and downstream pathway in HSCs remain controversial. METHODS: In this study, we investigated the regulatory role of S1P/S1P receptor (S1PR) in Hippo-YAP activation in both LX-2 cell lines and primary HSCs. Real-time PCR, western blot, pharmacological inhibitors, siRNAs, and Rho activity assays were adopted to address the molecular mechanisms of S1P mediated YAP activation. RESULTS: Serum and exogenous S1P significantly increased the expression of YAP target genes in HSCs. Pharmacologic inhibitors and siRNA-mediated knockdowns of S1P receptors showed S1P receptor 2 (S1PR2) as the primary mediator for S1P-induced CTGF expression in HSCs. Results using siRNA-mediated knockdown, Verteporfin, and Phospho-Tag immunoblots showed that S1P-S1PR2 signaling effectively suppressed the Hippo kinases cascade, thereby activating YAP. Furthermore, S1P increased RhoA activities in cells and ROCK inhibitors effectively blocked CTGF induction. Cytoskeletal-perturbing reagents were shown to greatly modulate CTGF induction, suggesting the important role of actin cytoskeleton in S1P-induced YAP activation. Exogeneous S1P treatment was enough to increase the expression of COL1A1 and α-SMA, that were blocked by YAP specific inhibitor. CONCLUSIONS: Our data demonstrate that S1P/S1PR2-Src-RhoA-ROCK axis leads to Hippo-YAP activation, resulting in the up-regulation of CTGF, COL1A1 and α-SMA expression in HSCs. Therefore, S1PR2 may represent a potential therapeutic target for hepatic fibrosis.

[Analysis of core functional components in Yinchenhao Decoction and their pathways for treating liver fibrosis].

OBJECTIVE: To analyze the core functional component groups (CFCG) in Yinchenhao Decoction (YCHD) and their possible pathways for treating hepatic fibrosis based on network pharmacology. METHODS: PPI data were extracted from DisGeNET, Genecards, CMGRN and PTHGRN to construct a weighted network using Cytoscape 3.9.1. The data of the chemical components in YCHD were obtained from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), and the potential active components and targets were selected using PreADMET Web server and SwissTargetPrediction. A fusion model was constructed to obtain the functional effect space and evaluate the effective proteins to identify the CFCG followed by GO and KEGG pathway enrichment analyses for all the targets. In cultured human hepatic stellate cells (LX-2 cells), the cytotoxicity of different compounds in YCHD was tested using CCK-8 assay; the effects of these compounds on collagen α1 (Col1a1) mRNA expression and the pathways in 20 ng/mL TGF-ß1-stimulated cells were analyzed using RT-qPCR and Western blotting. RESULTS: A total of 1005 pathogenic genes, 226 potential active components and 1529 potential targets in YCHD and 52 potential targets of CFCG were obtained. Benzyl acetate, vanillic acid, clorius, polydatin, lauric acid and ferulic acid were selected for CCK-8 verification, and they all showed minimal cytotoxicity below the concentration of 200 µmol/L. Clorius, polydatin, lauric acid and ferulic acid all effectively inhibited TGF-ß1-induced LX-2 cell activation. At the concentration of 200 µmol/L, all these 4 components inhibited PI3K, p-PI3K, AKT, p-AKT, ERK, p-ERK, P38 MAPK and p-P38 MAPK expressions in TGF-ß1-induced LX-2 cells. CONCLUSION: The therapeutic effect of YCHD on hepatic fibrosis is probably mediated by its core functional components including benzyl acetate, vanillic acid, clorius, polydatin, lauric acid and ferulic acid, which inhibit the PI3K-AKT and MAPK pathways in hepatic stellate cells.

CircRNA_001373 promotes liver fibrosis by regulating autophagy activation in hepatic stellate cells via the miR-142a-5p/Becn1 axis.

The purpose of this study was to investigate the regulatory role and underlying mechanisms of circRNA_001373 in the hepatic stellate cell (HSC) activation. Quantitative real-time polymerase chain reaction was used to detect the expression of circRNA_001373, miR-142a-5p and Becn1. The viability of JS-1 cells was measured by Cell Counting Kit-8. The targeting relationship between miR-142a-5p and CircRNA_001373, as well as between miR-142a-5p and Becn1 was predicted using CircInteractome and TargetScan databases, respectively, and validated by dual-luciferase reporter assay. Western blot was utilized to determine the expression levels of proteins related to autophagy and the activation if HSCs in JS-1 cells. After activation by platelet-derived growth factor-BB, an increase was observed in the expression of collagen I and α-smooth muscle actin proteins. The expression of CircRNA_001373 was up-regulated in the activated HSCs. Knockdown of CircRNA_001373 significantly inhibited cell viability and activation of JS-1 cells, as well as autophagy in the activated HSCs. CircRNA_001373 could sponge miR-142a-5p in the activated HSCs, which in turn elevated the Becn1 expression. Concurrent knockdown of both CircRNA_001373 and miR-142a-5p reversed the inhibitory effects of the knockdown of CircRNA_001373 alone on cell viability and autophagy in activated JS-1 cells. CircRNA_ 001373 promotes cell viability and autophagy as well as the activation of JS-1 cells by regulating the miR-142a-5p/Becn1 axis.

Gentiana decoction inhibits liver fibrosis and the activation of hepatic stellate cells via upregulating the expression of Parkin.

Liver fibrosis is a wound-healing process. It can be induced by various chronic liver diseases. Liver fibrosis is characterized by the activation of hepatic stellate cells (HSCs), a key event. However, no effective treatment strategies to cure or alleviate liver fibrosis-induced pathologic changes have yet been developed. Traditional Chinese medicine (TCM) exhibits a good anti-fibrosis action, with few side effects. Gentiana decoction, a TCM also called Longdan Xiegan Tang (LXT), is used for purging the liver in clinical settings. However, the role of LXT in preventing liver fibrosis and the underlying regulatory mechanism have not yet been investigated. This study demonstrates that LXT treatment can protect the liver from the injuries resulting from CCl4-induced liver fibrosis in mice and suppress the activation of HSCs. The mice in the LXT group exhibit litter collagen I and HSC activation marker α-smooth muscle actin (α-SMA) expression. Transcriptome sequencing of the mouse liver tissue reveals that the level of Parkin, a mitophagy marker, decreased in CCl4-induced liver fibrosis. Further study shows that the injection of Parkin-overexpression adeno-associated virus (Parkin-AAV) via the tail vein can reduce CCl4-induced liver fibrogenesis in mice. We conducted a mechanistic study also, which suggests that LXT treatment suppresses the activation of HSCs by upregulating the expression of Parkin. Hence, it can be suggested that LXT inhibits liver fibrosis by activating the Parkin signaling pathway.

Exploring novel A2AAR antagonists: Design, synthesis, and evaluation of 2,6,9-trisubstituted purine derivatives as promising antifibrotic agents.

A series of 2,6,9-trisubstituted purine derivatives were designed and synthesized with diverse chemical moieties. Through a comprehensive biological evaluation, we identified 4-(6-(methylamino)-2-(phenylethynyl)-9H-purin-9-yl)phenol (6a) as a promising A2AAR antagonist with potent antifibrotic properties. Compound 6a demonstrated significant efficacy in inhibiting CRE promoter activity and in reducing the expression of fibrogenic marker proteins and downstream effectors of A2AAR activation, surpassing the A2AAR antagonist ZM241385 and initial screening hits, 9-benzyl-N-methyl-2-(phenylethynyl)-9H-purin-6-amine (5a) and 9-((benzyloxy)methyl)-N-methyl-2-(phenylethynyl)-9H-purin-6-amine (5j). Further validation revealed that compound 6a effectively inhibited fibrogenic marker proteins induced by A2AAR overexpression or TGF-ß1 treatment in hepatic stellate cells, alongside reducing PKA and CREB phosphorylation. These findings suggest that compound 6a exerts its antifibrotic action by modulating the cAMP/PKA/CREB pathway through A2AAR inhibition. Overall, our study provides valuable insights for the development of novel therapeutics that target hepatic fibrosis through A2AAR antagonism.

Trimethylamine N-oxide induces non-alcoholic fatty liver disease by activating the PERK.

Nonalcoholic fatty liver disease (NAFLD) is a liver disease causing different progressive pathological changes. Trimethylamine N-oxide (TMAO), a product of gut microbiota metabolism, is a specific agonist of the protein kinase R-like endoplasmic reticulum kinase (PERK) pathway, one of the endoplasmic reticulum stress (ERS) pathways. TMAO has been associated with the occurrence and development of NAFLD based on the results of previous studies, but whether the simple consumption of TMAO can directly induce NAFLD and its underlying mechanism remain unclear. To investigate this question, we constructed an animal model in which adult male zebrafish were fed a controlled diet containing 1 % or 3 % TMAO for 20 weeks. Eventually, we observed that TMAO caused lipid accumulation, inflammatory infiltration, liver injury and liver fibrosis in zebrafish livers; meanwhile, the PERK signaling pathway was activated in the zebrafish livers. This finding was further confirmed in HepG2 cells and hepatic stellate cells models. In conclusion, this study found that TMAO directly induced different pathological states of NAFLD in zebrafish liver, and the activation of PERK pathway is an important mechanism, which may provide crucial strategies for the diagnosis and treatment of NAFLD.

PPARß/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)ß/δ in hepatic fibrosis remains a subject of debate. Here, we examined the effects of a PPARß/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-ß (TGF-ß). The PPARß/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, PPARß/δ activation abrogated TGF-ß1-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-ß1, 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 PPARß/δ agonist reduces TGF-ß1-mediated activation of HSCs and fibrosis via the reduction of both SMAD3 phosphorylation and p300 levels.

Microplastic-induced hepatic adverse effects evaluated in advanced quadruple cell human primary models following three weeks of repeated exposure.

Nano and microplastics are defined as particles smaller than 100 nm and 5 mm respectively. The widespread production and use of plastics in everyday life has resulted in significant accumulation of plastic debris in the environment. Over the last two decades there are increased concerns regarding the potential entry and accumulation of plastics in the human body with ingestion being one of the most important routes of exposure. However, the magnitude and nature of potential toxic effects of plastic exposure to human health is not yet fully understood. The liver is the body's principal detoxification organ and critically to this study recognized as the main accumulation site for particulates. In this study as the first of its kind the health impacts of long term low repeated polystyrene microplastics (1 and 5 µm) exposure was investigated in a functionally active 3D liver microtissue model, composed of primary human hepatocytes, Kupffer cells, sinusoidal endothelial cells and hepatic stellate cells. The highlight from the data includes microplastic-induced dose (3.125-25 µg/ml) and time dependent (up to 504 h) increase in cell death and inflammation manifested by enhanced release of IL6, IL8 and TNF-α. The exposure to repeated dosing of the plastics also resulted in notable pathology manifested as aberrant tissue architecture, such as dilated bile canaliculi and large lipid droplets inside the hepatic cells. This toxicity matched extremely well to the accumulation of the materials with the cells of microtissue predominately in the organ macrophages. This study highlights the real issue and danger of microplastic exposure with potential for long-term accumulation and adverse effects of non-biodegradable plastics within the liver.

Imperatorin attenuates CCl4-induced cirrhosis and portal hypertension by improving vascular remodeling and profibrogenic pathways.

BACKGROUND: Cirrhosis leads to portal hypertension (PHT), affecting survival with limited treatment options. This study investigated Imperatorin (IMP), a furanocoumarin with anti-inflammatory and hypotensive properties, for its therapeutic role and mechanisms in cirrhotic PHT. METHODS: Hepatic stellate cells (HSCs) inhibition by IMP was evaluated using LX-2 cell line. Rat cirrhosis was induced via CCl4 for 16 weeks. Experimental group were orally administered IMP (15/25 mg/kg/day) for 4 weeks. We subsequently examined portal pressure (PP), cirrhosis, inflammation, angiogenesis, and vascular remodeling. Network pharmacology was employed for mechanistic insights. RESULTS: IMP significantly inhibited the fibrogenesis in HSCs and suppressed cell viability. CCl4 exposure induced cirrhosis, inflammation, angiogenesis, vascular remodeling and PHT. IMP significantly reduced PP from 22.85 ± 3.88 mmHg to 6.67 ± 0.6 mmHg, diminished collagen deposition and pro-fibrotic factor expression, alleviated inflammation, and improved liver function. Vessel wall thickness in superior mesenteric arteries was restored, and intra-/extrahepatic angiogenesis was inhibited via VEGF and vWF. Furthermore, IMP induced sinusoidal vasodilation by upregulating eNOS and GCH1. Enrichment analysis indicated that IMP was involved in various biological processes associated with cirrhosis, such as the regulation of blood pressure, tissue remodeling, response to inflammation, and regulation of angiogenesis, etc. Additionally, IMP suppressed hepatic expression of TGF-ß both in vitro and in vivo, which was further supported by KEGG analysis. CONCLUSION: Our research demonstrated that IMP significantly mitigated cirrhosis PHT by reducing hepatic fibrosis and inflammation, curbing angiogenesis and vascular remodeling, and promoting vasodilation. This protective mechanism appears to be facilitated through the downregulation of TGF-ß.

Jiawei Taohe Chengqi Decoction attenuates CCl4 induced hepatic fibrosis by inhibiting HSCs activation via TGF-ß1/CUGBP1 and IFN-γ/Smad7 pathway.

BACKGROUND: Hepatic fibrosis (HF) is an essential stage in the progression of different chronic liver conditions to cirrhosis and even hepatocellular carcinoma. The activation of hepatic stellate cells (HSCs) plays a crucial role in the progression of HF. IFN- γ/Smad7 pathway can inhibit HSCs activation, while TGF-ß1/CUGBP1 pathway can inhibit IFN-γ/Smad7 pathway transduction and promote HSCs activation. Thus, inhibiting the TGF-ß1/CUGBP1 pathway and activating the IFN-γ/Smad7 pathway reverses HSCs activation and inhibits HF. Jiawei Taohe Chengqi Decoction (JTCD) was derived from the Taohe Chengqi Tang in the ancient Chinese medical text titled "Treatise on Febrile Diseases". We found several anti-HF components in JTCD including ginsenoside Rb1 and others, but the specific mechanism of anti-HF in JTCD is not clear. PURPOSE: To elucidate the specific mechanism by which JTCD reverses HF by inhibiting the activation of HSCs, and to establish a scientific foundation for treating HF with Traditional Chinese medicine (TCM). METHODS: We constructed a CCl4-induced mice HF model in vivo and activated human hepatic stellate cell line (LX-2) with TGF-ß1 in vitro, after which they were treated with JTCD and the corresponding inhibitors. We examined the expression of pivotal molecules in the two pathways mentioned above by immunofluorescence staining, Western blotting and RT-PCR. RESULTS: JTCD attenuated liver injury and reduced serum ALT and AST levels in mice. In addition, JTCD attenuated CCl4-induced HF by decreasing the expression of α-SMA, COL1A1 and other markers of HSCs activation in mice liver tissue. Moreover, JTCD effectively suppressed the levels of TGF-ß1, p-Smad3, p-p38MAPK, p-ATF2, and CUGBP1 in vivo and in vitro and upregulated the levels of IFN-γ, p-STAT1, and Smad7. Mechanically, after using the inhibitors of both pathways in vitro, we found that JTCD inhibited the activation of HSCs by restoring the balance of the TGF-ß1/CUGBP1 and IFN-γ/Smad7 pathways. CONCLUSION: We demonstrated that JTCD inhibited HSCs activation and reversed HF by inhibiting the TGF-ß1/CUGBP1 signalling pathway and upregulating the IFN-γ/Smad7 signalling pathway. Moreover, we have identified specific links where JTCD interferes with both pathways to inhibit HSCs activation. JTCD is an effective candidate for the clinical treatment of HF.

Glycyrrhizic acid ameliorates hepatic fibrosis by inhibiting oxidative stress via AKR7A2.

BACKGROUND: Hepatic fibrosis is a reversible pathological phenomenon caused by the abnormal proliferation of connective tissues in the liver for self-repair after persistent liver injury. Among these tissues, the activation status of hepatic stellate cells (HSCs) is crucial. Glycyrrhizic acid (GA) agents have been proven to have excellent anti-fibrosis effects, but their targets are unclear. PURPOSE: To investigate the anti-hepatic fibrosis effect of GA and its target in activated HSCs. METHODS: A mouse model of hepatic fibrosis was prepared with 20 % carbon tetrachloride (CCl4) and GA was administered continuously for 4 weeks. Subsequently, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), type Ⅲ procollagen peptide (P III P), laminin (LN), hyaluronic acid (HA), and type Ⅳ collagen (Col Ⅳ) were measured. Liver tissues were subjected to hematoxylin and eosin (HE), Masson, and Sirius red staining and proteome sequencing analysis. Based on LX-2 cells, activity-based protein profiling (ABPP) was used to investigate the potential targets of GA, which was further validated by the cellular thermal shift assay (CETSA), immunofluorescence co-localization, molecular docking, small interfering RNA (siRNA) and western blot (WB) assays. RESULTS: In vivo, GA significantly reduced serum ALT, AST, HA, P III P, Col IV, and LN levels. HE, Masson, and Sirius red staining showed that GA significantly ameliorated hepatic inflammatory response and collagen deposition in CCl4-treated mice. Proteome sequencing results showed that GA mainly regulated glutathione S-transferase family members involved in glutathione metabolism. In vitro, GA significantly inhibited LX-2 cell proliferation and reduced reactive oxygen species accumulation. ABPP suggested that aldo-keto reductase family 7 member A2 (AKR7A2) was the major binding protein of GA in LX-2 cells. CETSA, fluorescence co-localization, molecular docking, and surface plasmon resonance further validated GA binding to AKR7A2. The WB results showed that GA up-regulated AKR7A2 expression both in vitro and in vivo and was corroborated by siRNA experiments. CONCLUSION: GA targeted AKR7A2 in LX-2 cells to defend against sustained oxidative stress injury, thereby inhibiting the proliferation of activated HSCs and reversing hepatic fibrosis.

The potential of flavonoids in hepatic fibrosis: A comprehensive review.

BACKGROUND: Hepatic fibrosis is a pathophysiological process of extracellular matrix abnormal deposition induced by multiple pathogenic factors. Currently, there is still a lack of effective and non-toxic drugs for treating fibrosis in clinic. Flavonoids are polyphenolic compounds synthesized in plants and modern pharmacological studies confirmed flavonoids exhibit potent hepatoprotective effect. PURPOSE: Summarize literature to elaborate the mechanism of HF and evaluate the potential of flavonoids in HF, aiming to provide a new perspective for future research. METHODS: The literatures about hepatic fibrosis and flavonoids are collected via a series of scientific search engines including Google Scholar, Elsevier, PubMed, CNKI, WanFang, SciFinder and Web of Science database. The key words are "flavonoids", "hepatic fibrosis", "pharmacokinetic", "toxicity", "pathogenesis" "traditional Chinese medicine" and "mechanism" as well as combination application. RESULTS: Phytochemical and pharmacological studies revealed that about 86 natural flavonoids extracted from Chinese herbal medicines possess significantly anti-fibrosis effect and the mechanisms maybe through anti-inflammatory, antioxidant, inhibiting hepatic stellate cells activation and clearing activated hepatic stellate cells. CONCLUSIONS: This review summarizes the flavonoids which are effective in HF and the mechanisms in vivo and in vitro. However, fewer studies are focused on the pharmacokinetics of flavonoids in HF model and most studies are limited to preclinical studies, therefore there is no reliable data from clinical trials for the development of new drugs. Further in-depth research related it can be conducted to improve the bioavailability of flavonoids and serve the development of new drugs.

Total flavonoids of litchi Seed alleviates schistosomiasis liver fibrosis in mice by suppressing hepatic stellate cells activation and modulating the gut microbiomes.

Infection with Schistosoma japonicum (S. japonicum) is an important zoonotic parasitic disease that causes liver fibrosis in both human and domestic animals. The activation of hepatic stellate cells (HSCs) is a crucial phase in the development of liver fibrosis, and inhibiting their activation can alleviate this progression. Total flavonoids of litchi seed (TFL) is a naturally extracted drug, and modern pharmacological studies have shown its anti-fibrotic and liver-protective effects. However, the role of TFL in schistosomiasis liver fibrosis is still unclear. This study investigated the therapeutic effects of TFL on liver fibrosis in S. japonicum infected mice and explored its potential mechanisms. Animal study results showed that TFL significantly reduced the levels of Interleukin-1ß (IL-1ß), Tumor Necrosis Factor-α (TNF-α), Interleukin-4 (IL-4), and Interleukin-6 (IL-6) in the serum of S. japonicum infected mice. TFL reduced the spleen index of mice and markedly improved the pathological changes in liver tissues induced by S. japonicum infection, decreasing the expression of alpha-smooth muscle actin (α-SMA), Collagen I and Collagen III protein in liver tissues. In vitro studies indicated that TFL also inhibited the activation of HCSs induced by Transforming Growth Factor-ß1 (TGF-ß1) and reduced the levels of α-SMA. Gut microbes metagenomics study revealed that the composition, abundance, and functions of the mice gut microbiomes changed significantly after S. japonicum infection, and TLF treatment reversed these changes. Therefore, our study indicated that TFL alleviated granulomatous lesions and improved S. japonicum induced liver fibrosis in mice by inhibiting the activation of HSCs and by improving the gut microbiomes.

Cysteine sulfenylation contributes to liver fibrosis via the regulation of EphB2-mediated signaling.

Sulfenylation is a reversible oxidative posttranslational modification (PTM) of proteins on cysteine residues. Despite the dissection of various biological functions of cysteine sulfenylation, its roles in hepatic fibrosis remain elusive. Here, we report that EphB2, a receptor tyrosine kinase previously implicated in liver fibrosis, is regulated by cysteine sulfenylation during the fibrotic progression of liver. Specifically, EphB2 is sulfenylated at the residues of Cys636 and Cys862 in activated hepatic stellate cells (HSCs), leading to the elevation of tyrosine kinase activity and protein stability of EphB2 and stronger interactions with focal adhesion kinase for the activation of downstream mitogen-activated protein kinase signaling. The inhibitions of both EphB2 kinase activity and cysteine sulfenylation by idebenone (IDE), a marketed drug with potent antioxidant activity, can markedly suppress the activation of HSCs and ameliorate hepatic injury in two well-recognized mouse models of liver fibrosis. Collectively, this study reveals cysteine sulfenylation as a new type of PTM for EphB2 and sheds a light on the therapeutic potential of IDE for the treatment of liver fibrosis.

Lactucin reverses liver fibrosis by inhibiting TGF-ß1/STAT3 signaling pathway and regulating short-chain fatty acids metabolism.

TGF-ß1 activation of hepatic stellate cells (HSCs), transcriptional activator 3 (Stat3) activation and short chain fatty acids (SCFAs), metabolite of intestinal bacteria, is closely associated with hepatic fibrosis. Previous studies have shown that Lactucin has significant anti-inflammatory and hepatoprotective effects; however, the mechanism of Lactucin's role in liver fibrosis associated with SCFAs remains unknown. This study was intended to investigate whether effect of Lactucin on liver fibrosis was mediated by TGF-ß1/Stat3 and SCFAs. We found that Lactucin induced apoptosis in HSC-T6 cells, and inhibition of nuclear translocation of Stat3 and p-Stat3. And Smad3 and TGF-ß1 protein expression was significantly inhibited, while TLR4 and Smad7 protein expression was significantly enhanced. For in vivo experiments, we demonstrated that Lactucin alleviated liver fibrosis in mice, as evidenced by a reduction in inflammatory factors, collagen deposition, liver injury and fibrosis-related factors expression, especially the expression of Smad3 and TGF-ß1 proteins was significantly suppressed and Smad7 protein expression was significantly increased in the liver. In addition, the levels of acetic acid, butyric acid and valeric acid in the intestine of Lactucin-treated mice were significantly higher than those in the intestine of liver fibrosis mice. In conclusion, based on the results of in vivo and in vitro experiments, preventive mechanism of Lactucin against liver fibrosis in mice may be to improve the enterohepatic circulation by regulating the metabolites of intestinal microorganisms, acetic acid and butyric acid, and to further regulate the Stat3 and TGF-ß1 signaling pathway through the "gut-liver axis" to combat liver fibrosis.

Carfilzomib shows therapeutic potential for reduction of liver fibrosis by targeting hepatic stellate cell activation.

Because hepatic stellate cells (HSCs) play a major role in fibrosis, we focused on HSCs as a potential target for the treatment of liver fibrosis. In this study, we attempted to identify drug candidates to inactivate HSCs and found that several proteasome inhibitors (PIs) reduced HSC viability. Our data showed that a second-generation PI, carfilzomib (CZM), suppressed the expression of fibrotic markers in primary murine HSCs at low concentrations of 5 or 10 nM. Since CZM was not toxic to HSCs up to a concentration of 12.5 nM, we examined its antifibrotic effects further. CZM achieved a clear reduction in liver fibrosis in the carbon tetrachloride (CCl4)-induced mouse model of liver fibrosis without worsening of liver injury. Mechanistically, RNA sequence analysis of primary HSCs revealed that CZM inhibits mitosis in HSCs. In the CCl4-injured liver, amphiregulin, which is known to activate mitogenic signaling pathways and fibrogenic activity and is upregulated in murine and human metabolic dysfunction-associated steatohepatitis (MASH), was downregulated by CZM administration, leading to inhibition of mitosis in HSCs. Thus, CZM and next-generation PIs in development could be potential therapeutic agents for the treatment of liver fibrosis via inactivation of HSCs without liver injury.

GSK805 inhibits alpha-smooth muscle expression and modulates liver inflammation without impairing the well-being of mice.

Cholestatic liver diseases, such as primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), lead to inflammation and severe hepatic damage with limited therapeutic options. This study assessed the efficacy of the inverse RORγt agonist, GSK805, both in vitro using the hepatic stellate cell-line LX-2 and in vivo using male bile duct-ligated BALB/c mice. In vitro, 0.3 µM GSK805 reduced alpha-smooth muscle actin expression in LX-2 cells. In vivo, GSK805 significantly decreased IL-23R, TNF-α, and IFN-γ expression in cholestatic liver. Despite high concentrations of GSK805 in the liver, no significant reduction in fibrosis was noticed. GSK805 significantly increased aspartate aminotransferase and alanine aminotransferase activity in the blood, while levels of glutamate dehydrogenase, alkaline phosphatase, and bilirubin were not substantially increased. Importantly, GSK805 did neither increase an animal distress score nor substantially reduce body weight, burrowing activity, or nesting behavior. These results suggest that a high liver concentration of GSK805 is achieved by daily oral administration and that this drug modulates inflammation in cholestatic mice without impairing animal well-being.

Pregnane X receptor inhibits the transdifferentiation of hepatic stellate cells by down-regulating periostin expression.

Pregnane X receptor (PXR) is a xenobiotic-sensing nuclear receptor that plays a key role in drug metabolism. Recently, PXR was found to attenuate the development of liver cancer by suppressing epithelial-mesenchymal transition (EMT) in liver cancer cells in a mouse model of two-stage chemical carcinogenesis. To elucidate the role of PXR in the EMT of liver cancer cells, we focused on its role in hepatic stellate cells (HSCs), which are components of the tumor microenvironment in hepatocellular carcinoma (HCC). Human HSC-derived LX-2 cells stably expressed destabilization domain (DD)-fused human PXR (hPXR-LX2 cells). Human HCC-derived HepG2 cells were transfected with the EMT marker VIM promoter-regulated reporter plasmid and co-cultured with hPXR-LX2 cells or treated with hPXR-LX2-derived conditioned medium (CM). Co-culture or CM treatment increased reporter activity in HepG2 cells. This induction was attenuated upon PXR activation in hPXR-LX2 cells by treatment with the DD-stabilizing chemical Shield-1 and the human PXR ligand rifampicin. PXR activation in hPXR-LX2 cells exhibited inhibition of TGF-ß1-induced transdifferentiation, supported by observations of morphological changes and protein or mRNA levels of the transdifferentiation markers COL1A1 and FN1. PXR activation in hPXR-LX2 cells also attenuated the mRNA levels of the key transdifferentiation factor, POSTN. Treatment of hPXR-LX2 cells with recombinant POSTN restored the PXR-mediated suppression of transdifferentiation. Reporter assays with the POSTN promoter showed that PXR inhibited the NF-κB-mediated transcription of POSTN. Consequently, PXR activation in HSCs is expected to inhibit transdifferentiation by down-regulating POSTN expression, thereby suppressing EMT of liver cancer cells.