Hepatic stellate cells as a target for the treatment of liver fibrosis

Structural characterization and therapeutic effect of Alhagi honey oligosaccharide on liver fibrosis in mice

Alhagi honey is derived from the secretory granules of Alhagi pseudoalhagi Desv., a leguminous plant commonly known as camelthorn. Modern medical research has demonstrated that the extract of Alhagi honey possesses regulatory properties for the gastrointestinal tract and immune system, as well as exerts anti-tumor, anti-oxidative, anti-inflammatory, anti-bacterial, and hepatoprotective effects. The aim of this study was to isolate and purify oligosaccharide monomers (referred to as Mel) from camelthorn and elucidate their structural characteristics. Subsequently, the impact of Mel on liver injury induced by carbon tetrachloride (CCl4) in mice was investigated. The analysis identified the isolated oligosaccharide monomer (α-D-Glcp-(1 → 3)-β-D-Fruf-(2 → 1)-α-D-Glcp), with the molecular formula C18H32O16. In a mouse model of CCl4-induced liver fibrosis, Mel demonstrated significant therapeutic effects by attenuating the development of fibrosis. Moreover, it enhanced anti-oxidant enzyme activity (glutathione peroxidase and superoxide dismutase) in liver tissues, thereby reducing oxidative stress markers (malondialdehyde and reactive oxygen species). Mel also improved serum albumin levels, lowered liver enzyme activities (aspartate aminotransferase and alanine aminotransferase), and decreased inflammatory factors (tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6). Immunohistochemistry, immunofluorescence, and western blotting analyses confirmed the ability of Mel to downregulate hepatic stellate cell-specific markers (collagen type I alpha 1 chain, alpha-smooth muscle actin, transforming growth factor-beta 1. Non-targeted metabolomics analysis revealed the influence of Mel on metabolic pathways related to glutathione, niacin, pyrimidine, butyric acid, and amino acids. In conclusion, the results of our study highlight the promising potential of Mel, derived from Alhagi honey, as a viable candidate drug for treating liver fibrosis. This discovery offers a potentially advantageous option for individuals seeking natural and effective means to promote liver health.

Liver protein and metabolite biolabels reveal hepatoprotective effects and active compounds of Eucommiae folium: Exploration of new application of herb based on multi-omics and bioinformatics

A biolabel-led research based on multi-omics and bioinformatics was applied to analyze the application value of Eucommiae folium (EF) in liver cirrhosis, as well as the mechanism of action and material basis. Multi-omics were used to analyze the biolabels and key pathways of EF intervention in liver tissue. Subsequently, based on the information, bioinformatics was used to analyze the application value of EF in liver disease, as well the mechanism of action and material basis. Finally, histopathological and target expression analyses in an animal model were used to verify biolabels analysis results. Multi-omics showed that 18 proteins and 10 metabolites involved in five key pathways were screened as biolabels. Bioinformatics suggested that the application value of EF for liver cirrhosis may be the highest among the liver diseases that it may treat. Additionally, EF and five active compounds (curcumol, eucalyptol, (+)-catechin, naringenin, and quercetin) may protect the cirrhotic liver against the excessive energy expenditure and hepatic stellate cells activation through suppressing the oxidative phosphorylation pathway in a CCl4-induced mouse model. This study provides reference and evidence for the application value of EF in liver diseases, especially liver cirrhosis.

Inulin-like polysaccharide ABWW may impede CCl4 induced hepatic stellate cell activation through mediating the FAK/PI3K/AKT signaling pathway in vitro & in vivo

Studies have shown that terrestrial acidic polysaccharides containing carboxyl groups and seaweed sulfated polysaccharides have strong potential in anti-liver fibrosis. However, there is no investigation on the anti-liver fibrosis of fructan, a ubiquitous natural polysaccharide. The present study aimed to understand the effect of fructan in ameliorating carbon tetrachloride (CCl4)-induced liver fibrosis in mice. Here, an inulin-like fructan ABWW from Achyranthes bidentata Bl. was characterized by fructose enzymatic hydrolysis, methylation analysis, ESI-MS, and NMR. It was composed of →2)-β-d-Fruf-(1→ and →2)-β-d-Fruf-(1, 6→, terminated with →1)-α-d-Glcp and →2)-β-d-Fruf residues. The biological studies showed that ABWW could improve liver damage and liver fibrosis induced by CCl4in vivo and inhibit hepatic stellate cell (HSC) activation and migration in vitro. We further demonstrated that ABWW inhibited LX2 activation via suppressing the FAK/PI3K/AKT signaling pathway. Hence, ABWW might be a potential novel active compound for anti-fibrosis new drug development.

CETP-derived Peptide Seq-1, the Key Component of HB-ATV-8 Vaccine Prevents Stress Responses, and Promotes Downregulation of Pro-Fibrotic Genes in Hepatocytes and Stellate Cells

BACKGROUND

The nasal vaccine HB-ATV-8 has emerged as a promising approach for NAFLD (non-alcoholic fatty liver disease) and atherosclerosis prevention. HB-ATV-8 contains peptide seq-1 derived from the carboxy-end of the Cholesteryl Ester Transfer Protein (CETP), shown to reduce liver fibrosis, inflammation, and atherosclerotic plaque formation in animal models. Beyond the fact that this vaccine induces B-cell lymphocytes to code for antibodies against the seq-1 sequence, inhibiting CETP's cholesterol transfer activity, we have hypothesized that beyond the modulation of CETP activity carried out by neutralizing antibodies, the observed molecular effects may also correspond to the direct action of peptide seq-1 on diverse cellular systems and molecular features involved in the development of liver fibrosis.

METHODS

The HepG2 hepatoma-derived cell line was employed to establish an in vitro steatosis model. To obtain a conditioned cell medium to be used with hepatic stellate cell (HSC) cultures, HepG2 cells were exposed to fatty acids or fatty acids plus peptide seq-1, and the culture medium was collected. Gene regulation of COL1A1, ACTA2, TGF-β, and the expression of proteins COL1A1, MMP-2, and TIMP-2 were studied.

AIM

To establish an in vitro steatosis model employing HepG2 cells that mimics molecular processes observed in vivo during the onset of liver fibrosis. To evaluate the effect of peptide Seq-1 on lipid accumulation and pro-fibrotic responses. To study the effect of Seq-1-treated steatotic HepG2 cell supernatants on lipid accumulation, oxidative stress, and pro-fibrotic responses in HSC.

RESULTS AND CONCLUSION

Peptide seq-1-treated HepG2 cells show a downregulation of COLIA1, ACTA2, and TGF-β genes, and a decreased expression of proteins such as COL1A1, MMP-2, and TIMP-2, associated with the remodeling of extracellular matrix components. The same results are observed when HSCs are incubated with peptide Seq-1-treated steatotic HepG2 cell supernatants. The present study consolidates the nasal vaccine HB-ATV-8 as a new prospect in the treatment of NASH directly associated with the development of cardiovascular disease.

Efficacy and potential mechanisms of the main active ingredients of astragalus mongholicus in animal models of liver fibrosis: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Astragalus mongholicus (AM) is a Qi-tonifying and immune-regulating herb widely used in traditional Chinese medicine (TCM), which is increasingly regarded as a profound complementary medication in the treatment of fibrosis disease. Astragaloside (AS), astragaloside flavonoids (AF) and astragaloside polysaccharides (APS) are the main active ingredients of Astragalus Mongholicus (AM) that have a significant therapeutic effect on liver fibrosis.

AIM OF THE STUDY

This systematic review and meta-analysis aims to evaluate the effects and possible mechanisms of the main active ingredients of AM including astragaloside (AS), astragalus flavone (AF) and astragalus polysaccharide (APS) in animal models of liver fibrosis.

MATERIALS AND METHODS

We systematically searched ten databases PubMed, Web of Science, Embase, Scopus, CINAHL, ProQuest database, China National Knowledge Internet (CNKI), VIP Information Chinese Periodical Service Platform (VIP), WangFang database and China Biology Medicine Disc (CBM) to identify relevant animal studies from inception to November 2022. The SYRCLE's risk of bias tool was used to assess the methodological quality. The statistical analysis was performed using RevMan 5.4 software.

RESULTS

Twenty-three studies involving 482 animals were included. Studies quality scores ranged from 4 to 5. Alanine aminotransferase (ALT) (SMD, -3.87; 95% CI, -5.09 to -2.65; P < 0.00001) aminotransferase (AST) (SMD, -4.43; 95% CI, -5.77 to -3.08; P < 0.00001), hydroxyproline (HYP) (SMD, -2.94; 95% CI, -3.83 to -2.05; P < 0.00001) and transforming growth factor-β1 (TGF-β1) (SMD, -2.82; 95% CI, -3.57 to -2.06; P < 0.00001) were the main outcome measures to be analyzed. The meta-analysis revealed that the main active ingredients of AM lowered the levels of known risk factors including liver index (SMD, -1.25; 95% CI, -1.63 to -0.87; P < 0.00001), degree of liver fibrosis (SMD, -1.93; 95% CI, -2.57 to -1.28; P < 0.00001), collagen α type I (Col)-1 (SMD, -3.71; 95% CI, -5.63 to -1.79; P = 0.0001), hyaluronic acid (HA) (SMD, -2.65; 95% CI, -3.69 to -1.61; P < 0.00001), laminin (LN) (SMD, -2.06; 95% CI, -2.51 to -1.61; P < 0.00001), type IV collagen (CIV) (SMD, -3.04; 95% CI, -4.34 to -1.74; P < 0.00001), procollagen typeIII (PCIII) (SMD, -2.60; 95% CI, -3.15 to -2.05; P < 0.00001), albumin (ALB) (SMD, -1.19; 95% CI, -1.63 to -0.75; P < 0.00001), total bilirubin (TBiL) (SMD, -3.63; 95% CI, -5.39 to -1.88; P < 0.0001), α-smooth muscle actin (α-SMA) (SMD, -5.27; 95% CI, -6.94 to -3.61; P < 0.00001) and Smad3 (SMD, -4.11; 95% CI, -7.17 to -1.05; P = 0.009) level.

CONCLUSION

Our meta-analysis demonstrates the effective role of the main active ingredients of AM in preclinical studies of liver fibrosis. The underlying mechanisms may be related to attenuation of oxidative stress, modulation of inflammatory response and inhibition of collagen production. However, due to the significant heterogeneity and poor quality of included studies, positive findings should be treated cautiously.

REGISTRATION

PROSPERO ID CRD42023382282.

Formation and Investigation of Cell-Derived Nanovesicles as Potential Therapeutics against Chronic Liver Disease

A new therapeutic approach using cell-derived nanovesicles (cdNVs) is offered here to overcome the lack of effective treatments for liver fibrosis, a reversible chronic liver disease. To achieve this goal the formation and purification of cdNVs from untreated, quiescent-like, or activated LX-2 cells, an immortalized human hepatic stellate cell (HSC) line with key features of transdifferentiated HSCs are established. Analysis of the genotype and phenotype of naïve and transdifferentiated LX-2 cells activated through transforming growth factor beta 1, following treatment with cdNVs, reveals a concentration-dependent fibrosis regression. The beneficial fibrosis-resolving effects of cdNVs are linked to their biomolecular corona. Liposomes generated using lipids extracted from cdNVs exhibit a reduced antifibrotic response in perpetuated LX-2 cells and show a reduced cellular uptake. However, incubation with soluble factors collected during purification results in a new corona, thereby restoring fibrosis regression activity. Overall, cdNVs display encouraging therapeutic properties, making them a promising candidate for the development of liver fibrosis resolving therapeutics.

Remodeling of the liver fibrosis microenvironment based on nilotinib-loaded multicatalytic nanozymes with boosted antifibrogenic activity

Liver fibrosis is a reversible pathological process caused by chronic liver damage and a major risk factor for hepatocellular carcinoma (HCC). Hepatic stellate cell (HSC) activation is considered the main target for liver fibrosis therapy. However, the efficiency of this strategy is limited due to the complex microenvironment of liver fibrosis, including excessive extracellular matrix (ECM) deposition and hypoxia-induced imbalanced ECM metabolism. Herein, nilotinib (NIL)-loaded hyaluronic acid (HA)-coated Ag@Pt nanotriangular nanozymes (APNH NTs) were developed to inhibit HSCs activation and remodel the microenvironment of liver fibrosis. APNH NTs efficiently eliminated intrahepatic reactive oxygen species (ROS) due to their inherent superoxide dismutase (SOD) and catalase (CAT) activities, thereby downregulating the expression of NADPH oxidase-4 (NOX-4) and inhibiting HSCs activation. Simultaneously, the oxygen produced by the APNH NTs further alleviated the hypoxic microenvironment. Importantly, the released NIL promoted collagen depletion by suppressing the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1), thus synergistically remodeling the microenvironment of liver fibrosis. Notably, an in vivo study in CCl4-induced mice revealed that APNH NTs exhibited significant antifibrogenic effects without obvious long-term toxicity. Taken together, the data from this work suggest that treatment with the synthesized APNH NTs provides an enlightening strategy for remodeling the microenvironment of liver fibrosis with boosted antifibrogenic activity.

Fluorofenidone alleviates liver fibrosis by inhibiting hepatic stellate cell autophagy via the TGF-β1/Smad pathway: implications for liver cancer

Objectives

Liver fibrosis is a key stage in the progression of various chronic liver diseases to cirrhosis and liver cancer, but at present, there is no effective treatment. This study investigated the therapeutic effect of the new antifibrotic drug fluorofenidone (AKF-PD) on liver fibrosis and its related mechanism, providing implications for liver cancer.

Materials and Methods

The effects of AKF-PD on hepatic stellate cell (HSC) autophagy and extracellular matrix (ECM) expression were assessed in a carbon tetrachloride (CCl4)-induced rat liver fibrosis model. In vitro, HSC-T6 cells were transfected with Smad2 and Smad3 overexpression plasmids and treated with AKF-PD. The viability and number of autophagosomes in HSC-T6 cells were examined. The protein expression levels of Beclin-1, LC3 and P62 were examined by Western blotting. The Cancer Genome Atlas (TCGA) database was used for comprehensively analyzing the prognostic values of SMAD2 and SMAD3 in liver cancer. The correlation between SMAD2, SMAD3, and autophagy-related scores in liver cancer was explored. The drug prediction of autophagy-related scores in liver cancer was explored.

Results

AKF-PD attenuated liver injury and ECM deposition in the CCl4-induced liver fibrosis model. In vitro, the viability and number of autophagosomes in HSCs were reduced significantly by AKF-PD treatment. Meanwhile, the protein expression of FN, α-SMA, collagen III, Beclin-1 and LC3 was increased, and P62 was reduced by the overexpression of Smad2 and Smad3; however, AKF-PD reversed these effects. SMAD2 and SMAD3 were hazardous factors in liver cancer. SMAD2 and SMAD3 correlated with autophagy-related scores in liver cancer. Autophagy-related scores could predict drug response in liver cancer.

Conclusions

AKF-PD alleviates liver fibrosis by inhibiting HSC autophagy via the transforming growth factor (TGF)-β1/Smadpathway. Our study provided some implications about how liver fibrosis was connected with liver cancer by SMAD2/SMAD3 and autophagy.

Lipid nanoparticles (LNPs) for in vivo RNA delivery and their breakthrough technology for future applications

RNA therapeutics show a significant breakthrough for the treatment of otherwise incurable diseases and genetic disorders by regulating disease-related gene expression. The successful development of COVID-19 mRNA vaccines further emphasizes the potential of RNA therapeutics in the prevention of infectious diseases as well as in the treatment of chronic diseases. However, the efficient delivery of RNA into cells remains a challenge, and nanoparticle delivery systems such as lipid nanoparticles (LNPs) are necessary to fully realize the potential of RNA therapeutics. While LNPs provide a highly efficient platform for the in vivo delivery of RNA by overcoming various biological barriers, several challenges remain to be resolved for further development and regulatory approval. These include a lack of targeted delivery to extrahepatic organs and a gradual loss of therapeutic potency with repeated doses. In this review, we highlight the fundamental aspects of LNPs and their uses in the development of novel RNA therapeutics. Recent advances in LNP-based therapeutics and preclinical/clinical studies are overviewed. Lastly, we discuss the current limitations of LNPs and introduce breakthrough technologies that might overcome these challenges in future applications.

Phloretin Ameliorates Succinate-Induced Liver Fibrosis by Regulating Hepatic Stellate Cells

BACKGRUOUND

Hepatic stellate cells (HSCs) are the major cells which play a pivotal role in liver fibrosis. During injury, extracellular stimulators can induce HSCs transdifferentiated into active form. Phloretin showed its ability to protect the liver from injury, so in this research we would like to investigate the effect of phloretin on succinate-induced HSCs activation in vitro and liver fibrosis in vivo study.

METHODS

In in vitro, succinate was used to induce HSCs activation, and then the effect of phloretin on activated HSCs was examined. In in vivo, succinate was used to generated liver fibrosis in mouse and phloretin co-treated to check its protection on the liver.

RESULTS

Phloretin can reduce the increase of fibrogenic markers and inhibits the proliferation, migration, and contraction caused by succinate in in vitro experiments. Moreover, an upregulation of proteins associated with aerobic glycolysis occurred during the activation of HSCs, which was attenuated by phloretin treatment. In in vivo experiments, intraperitoneal injection of phloretin decreased expression of fibrotic and glycolytic markers in the livers of mice with sodium succinate diet-induced liver fibrosis. These results suggest that aerobic glycolysis plays critical role in activation of HSCs and succinate can induce liver fibrosis in mice, whereas phloretin has therapeutic potential for treating hepatic fibrosis.

CONCLUSION

Intraperitoneal injection of phloretin attenuated succinate-induced hepatic fibrosis and alleviates the succinate-induced HSCs activation.

Exploration of potential mechanism of Rougan formula against hepatic fibrosis by network analysis and experimental assessment

ETHNOPHARMACOLOGICAL RELEVANCE

Rougan Formula (RG) has long been clinically applied to treat hepatic fibrosis in patients with different chronic liver diseases. However, the core active substances and the potential pharmacological mechanisms of RG remain unclear.

AIM OF THE STUDY

The purpose of this study is to explore bioactive components, key targets, and potential mechanisms of RG by performing network pharmacological analyses and experimental model validation.

MATERIALS AND METHODS

All chemical components in RG extract were identified using ultraperformance liquid chromatography-quadrupole/time-of-flight tandem mass technology. The candidate components and drug targets of RG, as well as disease-related genes, were extracted from TCMSP and GeneCards databases. The potential pathways related to genes were predicted by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. The core bioactive components, key targets, and signaling pathways were ultimately obtained by analyzing protein-protein interaction (PPI) and component-target-pathway (C-T-P) networks. Subsequently, the efficacy and underlying mechanisms of RG on hepatic fibrosis were experimentally validated in transforming growth factor-beta 1 (TGF-β1)-induced hepatic stellate cell activation model and CCL₄-induced hepatic fibrosis mouse model.

RESULTS

A total of 52 components in RG extract were obtained, and 22 of them were selected as the core bioactive components. Five hundred and thirty-nine overlapped targets were determined by matching drug targets with disease-related targets. The results of PPI and C-T-P network analyses revealed 100 key targets and 19 signaling pathways associated with RG efficacy. In vitro and in vivo studies further verified that RG exerted a significant anti-hepatic fibrotic effect by suppressing the activation of hepatic stellate cells by downregulating the TGF-β1/Smads signaling pathway.

CONCLUSIONS

These results may provide some evidence for further clinical research and development of RG formula as an effective and safe drug for hepatic fibrosis treatment.

Natural Compounds as Integrative Therapy for Liver Protection against Inflammatory and Carcinogenic Mechanisms: From Induction to Molecular Biology Advancement

The liver is exposed to several harmful substances that bear the potential to cause excessive liver damage ranging from hepatitis and non-alcoholic fatty liver disease to extreme cases of liver cirrhosis and hepatocellular carcinoma. Liver ailments have been effectively treated from very old times with Chinese medicinal herbal formulations and later also applied by controlled trials in Japan. However, these traditional practices have been hardly well characterized in the past till in the last decades when more qualified studies have been carried out. Modern advances have given rise to specific molecular targets which are specifically good candidates for affecting the intricate mechanisms that play a role at the molecular level. These therapeutic regimens that mainly affect the progression of the disease by inhibiting the gene expression levels or by blocking essential molecular pathways or releasing cytokines may prove to play a vital role in minimizing the tissue damage. This review, therefore, tries to throw light upon the variation in the therapies for the treatment of benign and malignant liver disease from ancient times to the current date. Nonetheless, clinical research exploring the effectiveness of herbal medicines in the treatment of benign chronic liver diseases as well as prevention and treatment of HCC is still warranted.

Tracking matricellular protein SPARC in extracellular vesicles as a non-destructive method to evaluate lipid-based antifibrotic treatments

Uncovering the complex cellular mechanisms underlying hepatic fibrogenesis could expedite the development of effective treatments and noninvasive diagnosis for liver fibrosis. The biochemical complexity of extracellular vesicles (EVs) and their role in intercellular communication make them an attractive tool to look for biomarkers as potential alternative to liver biopsies. We developed a solid set of methods to isolate and characterize EVs from differently treated human hepatic stellate cell (HSC) line LX-2, and we investigated their biological effect onto naïve LX-2, proving that EVs do play an active role in fibrogenesis. We mined our proteomic data for EV-associated proteins whose expression correlated with HSC treatment, choosing the matricellular protein SPARC as proof-of-concept for the feasibility of fluorescence nanoparticle-tracking analysis to determine an EV-based HSCs’ fibrogenic phenotype. We thus used EVs to directly evaluate the efficacy of treatment with S80, a polyenylphosphatidylcholines-rich lipid, finding that S80 reduces the relative presence of SPARC-positive EVs. Here we correlated the cellular response to lipid-based antifibrotic treatment to the relative presence of a candidate protein marker associated with the released EVs. Along with providing insights into polyenylphosphatidylcholines treatments, our findings pave the way for precise and less invasive diagnostic analyses of hepatic fibrogenesis.

A method is developed to isolate and characterize extracellular vesicles (EVs) from human hepatic stellate cells and proteomics reveals that the matricellular protein SPARC may be used as an EV marker after lipid-based antifibrotic treatment.

The role of p53 in liver fibrosis

The tumor suppressor p53 is the central hub of a molecular network, which controls cell proliferation and death, and also plays an important role in the occurrence and development of liver fibrosis. The abundant post-translational processing and modification endow the functional diversity of p53. Considering the relationship between p53 and liver fibrosis, drug intervention targeting p53 or management of p53 regulation might be effective strategies to treat liver fibrosis. Here, we systematically discuss the regulation of p53 in different liver cells (hepatocytes, immune cells, HSCs, etc) and the role of p53 in the development of liver fibrosis, and propose possible interventions to prevent the pathogenic processes of liver fibrosis.

Comparison of DLin-MC3-DMA and ALC-0315 for siRNA Delivery to Hepatocytes and Hepatic Stellate Cells

Ionizable cationic lipids are essential for efficient in vivo delivery of RNA by lipid nanoparticles (LNPs). DLin-MC3-DMA (MC3), ALC-0315, and SM-102 are the only ionizable cationic lipids currently clinically approved for RNA therapies. ALC-0315 and SM-102 are structurally similar lipids used in SARS-CoV-2 mRNA vaccines, while MC3 is used in siRNA therapy to knock down transthyretin in hepatocytes. Hepatocytes and hepatic stellate cells (HSCs) are particularly attractive targets for RNA therapy because they synthesize many plasma proteins, including those that influence blood coagulation. While LNPs preferentially accumulate in the liver, evaluating the ability of different ionizable cationic lipids to deliver RNA cargo into distinct cell populations is important for designing RNA-LNP therapies with minimal hepatotoxicity. Here, we directly compared LNPs containing either ALC-0315 or MC3 to knock-down coagulation factor VII (FVII) in hepatocytes and ADAMTS13 in HSCs. At a dose of 1 mg/kg siRNA in mice, LNPs with ALC-0315 achieved a 2- and 10-fold greater knockdown of FVII and ADAMTS13, respectively, compared to LNPs with MC3. At a high dose (5 mg/kg), ALC-0315 LNPs increased markers of liver toxicity (ALT and bile acids), while the same dose of MC3 LNPs did not. These results demonstrate that ALC-0315 LNPs achieves potent siRNA-mediated knockdown of target proteins in hepatocytes and HSCs, in mice, though markers of liver toxicity can be observed after a high dose. This study provides an initial comparison that may inform the development of ionizable cationic LNP therapeutics with maximal efficacy and limited toxicity.

Hesperetin derivative decreases CCl4 -induced hepatic fibrosis by Ptch1-dependent mechanisms

Hepatic fibrosis (HF), a continuous wound-healing response of the liver to repeated injuries, is characterized by abnormal extracellular matrix (ECM) accumulation. Hepatic stellate cells (HSCs) are considered a major cell type for ECM production. However, recent evidence indicates the lack of effective treatments for HF. Hesperetin, a Traditional Chinese Medicine monomer, has been isolated from the fruit peel of Citrusaurantium L. (Rutaceae). Growing evidence suggests the partial function of hesperetin in HF treatment. A hesperetin derivative (HD) was synthesized in our laboratory to increase the bioavailability and the water solubility of hesperetin. In this study, we detected the functions of HD in a mouse model of CCl₄ -induced HF and transforming growth factor-β1-stimulated HSC-T6 cells, in vivo and in vitro. HD reduced histological damage and CCl₄ -induced HF. Moreover, HD interference was associated with the activation of indicators in HSC-T6 cells, showing that HD is involved in HSCs activation in HF. Mechanistically, the Hedgehog pathway is involved in the HD treatment of HF, and HD may attenuate the aberrant expression of patched1. In conclusion, the studies indicate that HD may function as a potential antifibrotic Traditional Chinese Medicine monomer in HF therapy.

Grevillea robusta Delayed the Progression of Experimentally Induced Hepatic Fibrosis and Cirrhosis in Wistar Rats by Attenuating the Expression of Smooth Muscle Actin, Collagen, and TGF-β

The chronic damage to the liver causes fibrosis, especially when different proteins are accumulated in the liver, which is the basic characteristic of chronic liver damage. The excessive accumulation of the matrix protein such as collagen causes liver fibrosis. Liver fibrosis leads to cirrhosis, liver failure, and portal vein hypertension. Plants having antioxidants, free radical scavenging activities, and anti-inflammatory constituents are believed to be hepatoprotective in nature. Grevillea robusta (GR) is native to the subtropical environment. Its in vitro antioxidant, cytotoxic, and free radical scavenging activities are known, while the effect on liver fibrosis and cirrhosis remains elusive. The aim of this study was to evaluate the hepatoprotective and antifibrotic effects of Grevillea robusta plant. GR leaf extract (GREE) was prepared from the hydroethanolic extract (70%). Polyphenol and flavonoid contents and the in vitro antioxidant activity of the extract were determined. In vivo hepatitis was induced in Wistar rats by continual IP injections of CCl₄. GREE was administered by oral gavage at a dose of 100, 300, and 500 mg/kg of body weight once daily for 4 weeks. Variations in rat’s body weight, liver-to-body weight ratio, serum alanine aminotransferases, gamma-glutamyltransferase, liver histology, and cellular markers of liver fibrosis were evaluated. Serum levels of alanine aminotransferase (ALT) (p < 0.05) and gamma-glutamyltransferase (γ-GT) (p < 0.001) were decreased in the treatment group compared with the disease control group. RBC count was increased (p < 0.001) in the treatment group compared with the disease control group. The expression of alpha-SMA was downregulated to 40% (p < 0.05) and that of collagen was decreased by 9% (p < 0.05) compared with the disease control group. Extracellular matrix deposition and necrotic areas were also decreased as compared to the disease control group. It can be concluded that GR possesses hepatoprotective action by virtue of antioxidant constituents and delays the progression of liver cirrhosis by suppressing the activation of extracellular matrix–producing cells in the liver.

A new approach based on CXCR4-targeted combination liposomes for the treatment of liver fibrosis

Liver fibrosis results from excessive extracellular matrix accumulation due to injury and leads to cirrhosis, cancer, and death. Herein, we propose a chemokine receptor 4 (CXCR4)-targeted combination (CTC) liposomal therapy to treat carbon tetrachloride (CCl₄)-induced liver fibrosis in a mouse model. This study aims to combine small molecules such as pirfenidone and AMD3100 in a single nanoplatform to investigate their synergistic antifibrotic effects in a setting of CCl₄-induced liver fibrosis. CTC liposomes (CTC lipo) were prepared using the thin-film hydration method. CTC lipo exhibited a spherical shape, and the particle size was recorded at the nanoscale which confirms its appropriateness for in vitro and in vivo applications. CTC lipo had good storage and serum stability. The entrapped drugs in CTC lipo showed reduced toxicity at higher concentrations. CTC lipo displayed CXCR4 mediated cell uptake and were internalized by caveolae-mediated endocytosis. CTC lipo showed CXCR4 targeting and stromal cell-derived factor 1α (SDF1-α)/CXCR4 axis blocking activity. CTC lipo reduced the elevated serum aspartate aminotransferase (AST), alanine transaminase (ALT), and hydroxyproline (HYP) levels. The histological studies showed improved liver architecture and reduced collagen deposition after treatment. Transforming growth factor β (TGFβ), alpha-smooth muscle actin (α-SMA), and collagen I were elevated by CCl₄ in comparison with the Sham. Upon CTC liposomal treatment, the quantitative score for the elevated fibrotic proteins such as TGFβ, α-SMA, and collagen I was normalized. CTC lipo displayed significant downregulation of the upregulated TGFβ, α-SMA, collagen I, and P-p38 expressions at the molecular level. The CXCR4 targeted liposomes showed prolonged biodistribution at 24 h. Our findings indicated that CTC lipo might be an alternative antifibrotic therapy that may offer new access to research and development. In a nutshell, the present study suggests that systemic administration of CTC lipo has efficient antifibrotic potential and deserves to be investigated for further clinical applications.

Rubus chingii Hu. unripe fruits extract ameliorates carbon tetrachloride-induced liver fibrosis and improves the associated gut microbiota imbalance

BACKGROUND

The unripe fruits of Rubus chingii Hu. ("Fu-peng-zi" in Chinese) is a well-known herbal tonic in traditional Chinese medicine (TCM) for tonifying liver and kidney. However, little is known regarding its therapeutic efficacy against liver fibrosis and the underlying mechanism.

METHODS

The current research aims to explore the potential of Rubus chingii Hu. unripe fruits extract (RF) in the treatment of liver fibrosis and explore the underlying mechanism. RF was administered (450 and 900 mg·kg^- 1 of body weight per day) orally to male C57BL/6 mice with CCl₄-induced liver fibrosis for 3 weeks. The histopathological changes and fibrosis stage in liver tissue were assessed using hematoxylin and eosin (H&E) and Sirius red staining. The distribution of α-SMA and Col1A1 in the liver was analyzed to determine the hepatic stellate cells (HSCs) activation using immunohistochemistry and immunofluorescent analysis. Various biochemical markers in serum (ALT, AST) and liver (Hyp, IL1-β, IL6, TNF-α and MCP-1) were observed to assess the liver's injury, fibrosis, and inflammation. In liver tissue, fibrosis-associated proteins including α-SMA, TGF-β1, Smad2/3, p-Smad2/3, and Smad4 were detected through a Western blot assay. Pyrosequencing-based analysis of bacterial 16 S ribosomal RNA from variable regions V3-V4 of fecal samples characterized the gut microbiota. Spearman's rank correlation analysis was performed for the association between altered bacterial genera by RF and pharmacodynamics parameters.

RESULTS

Three weeks of RF treatment can significantly lower liver inflammatory levels, pathological abnormalities, and collagen fibrous deposition in mice with CCl₄-induced liver fibrosis. The expressions of α-SMA and Col1A1 were lowered by RF, while the expression levels of TGF-β/Smads signaling pathway-related proteins, including TGF-β1, p-Smad2/3, and Smad4, were dramatically decreased by RF. The RF treatment significantly increased or reduced 18 different bacterial species, restoring the CCl₄-induced gut microbiota imbalance to the normal group's levels. According to correlation analysis, the bacterial genera Bifidobacterium and Turicibacter were the most significant in restoring CCl₄-induced liver fibrosis.

CONCLUSIONS

RF can reduce liver damage and delay the onset of liver fibrosis through modulating TGF-β/Smads signaling pathway. Furthermore, RF's anti-liver fibrosis effect was related to balancing the gut microbial community, partly attained by increasing Bifidobacterium and Turicibacter in liver fibrosis.

Mass Cytometry Study on Hepatic Fibrosis and Its Drug-Induced Recovery Using Mouse Peripheral Blood Mononuclear Cells

The number of patients with liver diseases has increased significantly with the progress of global industrialization. Hepatic fibrosis, one of the most common liver diseases diagnosed in many developed countries, occurs in response to chronic liver injury and is primarily driven by the development of inflammation. Earlier immunological studies have been focused on the importance of the innate immune response in the pathophysiology of steatohepatitis and fibrosis, but recently, it has also been reported that adaptive immunity, particularly B cells, plays an essential role in hepatic inflammation and fibrosis. However, despite recent data showing the importance of adaptive immunity, relatively little is known about the role of B cells in the pathogenesis of steatohepatitis fibrosis. In this study, a single-cell-based, high-dimensional mass cytometric investigation of the peripheral blood mononuclear cells collected from mice belonging to three groups [normal chow (NC), thioacetamide (TAA), and 11beta-HSD inhibitor drug] was conducted to further understand the pathogenesis of liver fibrosis through reliable noninvasive biomarkers. Firstly, major immune cell types and their population changes were qualitatively analyzed using UMAP dimensionality reduction and two-dimensional visualization technique combined with a conventional manual gating strategy. The population of B cells displayed a twofold increase in the TAA group compared to that in the NC group, which was recovered slightly after treatment with the 11beta-HSD inhibitor drug. In contrast, the populations of NK cells, effector CD4⁺ T cells, and memory CD8⁺ T cells were significantly reduced in the TAA group compared with those in the NC group. Further identification and quantification of the major immune cell types and their subsets were conducted based on automated clustering approaches [PhenoGraph (PG) and FlowSOM]. The B-cell subset corresponding to PhenoGraph cluster PG#2 (CD62L^highCD44^highLy6c^high B cells) and PG#3 (CD62L^highCD44^highLy6c^low B cell) appears to play a major role in both the development of hepatic fibrosis and recovery via treatment, whereas PG#1 (CD62L^lowCD44^highLy6c^low B cell) seems to play a dominant role in the development of hepatic fibrosis. These findings provide insights into the roles of cellular subsets of B cells during the progression of, and recovery from, hepatic fibrosis.

The S100 calcium binding protein A11 promotes liver fibrogenesis by targeting TGF-β signaling

Liver fibrosis is a key transformation stage and also a reversible pathological process in various types of chronic liver diseases. However, the pathogenesis of liver fibrosis still remains elusive. Here, we report that the calcium binding protein A11 (S100A11) is consistently upregulated in the integrated data from GSE liver fibrosis and tree shrew liver proteomics. S100A11 is also experimentally activated in liver fibrosis in mouse, rat, tree shrew, and human with liver fibrosis. While overexpression of S100A11 in vivo and in vitro exacerbates liver fibrosis, the inhibition of S100A11 improves liver fibrosis. Mechanistically, S100A11 activates hepatic stellate cells (HSCs) and the fibrogenesis process via the regulation of the deacetylation of Smad3 in the TGF-β signaling pathway. S100A11 physically interacts with SIRT6, a deacetylase of Smad2/3, which may competitively inhibit the interaction between SIRT6 and Smad2/3. The subsequent release and activation of Smad2/3 promote the activation of HSCs and fibrogenesis. Additionally, a significant elevation of S100A11 in serum is observed in clinical patients. Our study uncovers S100A11 as a novel profibrogenic factor in liver fibrosis, which may represent both a potential biomarker and a promising therapy target for treating liver fibrosis and fibrosis-related liver diseases.

Combination therapy based on targeted nano drug co-delivery systems for liver fibrosis treatment: A review

Liver fibrosis is the hallmark of liver disease and occurs prior to the stages of cirrhosis and hepatocellular carcinoma. Any type of liver damage or inflammation can result in fibrosis. Fibrosis does not develop overnight, but rather as a result of the long-term action of injury factors. At present, however, there are no good treatment methods or specific drugs other than removing the pathogenic factors. Drug application is still limited, which means that drugs with good performance in vitro cannot achieve good therapeutic effects in vivo, owing to various factors such as poor drug targeting, large side effects, and strong hydrophobicity. Hepatic stellate cells (HSC) are the primary effector cells in liver fibrosis. The nano-drug delivery system is a new and safe drug delivery system that has many advantages which are widely used in the field of liver fibrosis. Drug resistance and side effects can be reduced when two or more drugs are used in combination drug delivery. Combination therapy of drugs with different targets has emerged as a novel approach to treating liver fibrosis, and the nano co-delivery system enhances the benefits of combination therapy. While nano co-delivery systems can maximize benefits while avoiding drug side effects, this is precisely the advantage of the nano co-delivery system. This review briefly described the pathogenesis and current treatment strategies, the different co-delivery systems of combination drugs in the nano delivery system, and targeting strategies for nano delivery systems on liver fibrosis therapy. Because of their superior performance, nano delivery systems and targeting drug delivery systems have received a lot of attention in the new drug delivery system. The new delivery systems offer a new pathway in the treatment of liver fibrosis, and it is believed that it can be a new treatment for fibrosis in the future. Nano co-delivery system of combination drugs and targeting strategies has proven the effectiveness of anti-fibrosis at the experimental level.

Alcoholic liver disease-from steatosis to cirrhosis - a biochemistry approach

Nowadays, chronic alcoholism and its health implications represent a global concern. Over three million deaths are linked to chronic alcohol intake every year. This article aims to spread awareness about the negative impact ethanol can have on almost every organ in the body, especially the liver. Understanding ethanol metabolism and the cellular pathways through which alcohol increases liver oxidative stress may prevent a broad spectrum of hepatic lesions such as steatosis, steatohepatitis, and, ultimately, cirrhosis. After a short review of ethanol metabolism and liver oxidative stress, each hepatic lesion will be individually discussed regarding the mechanism of apparition, treatment, and future targeted therapies.

GATA4 induces liver fibrosis regression by deactivating hepatic stellate cells

In response to liver injury, hepatic stellate cells activate and acquire proliferative and contractile features. The regression of liver fibrosis appears to involve the clearance of activated hepatic stellate cells, either by apoptosis or by reversion toward a quiescent-like state, a process called deactivation. Thus, deactivation of active hepatic stellate cells has emerged as a novel and promising therapeutic approach for liver fibrosis. However, our knowledge of the master regulators involved in the deactivation and/or activation of fibrotic hepatic stellate cells is still limited. The transcription factor GATA4 has been previously shown to play an important role in embryonic hepatic stellate cell quiescence. In this work, we show that lack of GATA4 in adult mice caused hepatic stellate cell activation and, consequently, liver fibrosis. During regression of liver fibrosis, Gata4 was reexpressed in deactivated hepatic stellate cells. Overexpression of Gata4 in hepatic stellate cells promoted liver fibrosis regression in CCl4-treated mice. GATA4 induced changes in the expression of fibrogenic and antifibrogenic genes, promoting hepatic stellate cell deactivation. Finally, we show that GATA4 directly repressed EPAS1 transcription in hepatic stellate cells and that stabilization of the HIF2α protein in hepatic stellate cells leads to liver fibrosis.

Therapeutic potential of Saccharomyces boulardii in liver diseases: from passive bystander to protective performer?

Saccharomyces boulardii (S. boulardii) is a probiotic yeast that has been elucidated to be efficacious in fighting various gastrointestinal diseases in preclinical as well as clinical studies. Its general mechanisms of probiotic action in the treatment of gastrointestinal conditions cover multifaceted aspects, including immune regulation, production of antimicrobial substances, pathogen competitive elimination, gut barrier integrity maintenance, intestinal trophic effect and antioxidant potency. In this review, basic knowledge with regard to the gut-liver axis, available probiotics remedies and mechanistic insights of S. boulardii as probiotics will be elucidated. In addition, we summarize the therapeutic potential of S. boulardii in several liver diseases evident from both bench and bedside information, such as acute liver injury/failure, fibrosis, hepatic damages due to metabolic disturbance or infection and obstructive jaundice. Future prospects in relation to medicinal effects of S. boulardii are also exploited and discussed on the basis of novel and attractive therapeutic concept in the latest scientific literature.

The Effects of Freshwater Clam (Corbicula fluminea) Extract on Activated Hepatic Stellate Cells

Background

The extract of freshwater clams has been used to protect the body against liver diseases in traditional folk medicine. This study aims at investigating the effects of freshwater clam extract on activated hepatic stellate cells (aHSCs), which are critical contributors to liver fibrosis.

Methods

The aHSCs used in this study were derived from hepatic stellate cells that were isolated and purified from the livers of male Wistar rats and then transformed into the activated phenotype by culturing on uncoated plastic dishes. Freshwater clam extract (CE) was collected after the outflow from the live freshwater clams in a water bath at 100°C for 60 min. The effects of CE on aHSCs were analyzed by MTT assay, flow cytometry, Oil Red O (ORO) staining, western blot, and real-time RT-PCR.

Results

The results indicated that CE suppressed the proliferation of aHSCs through G0/G1 cell cycle arrest by downregulating cyclin D1 and upregulating p27. The expression levels of a-SMA, collagen I, TGF-β, and TNF-α were inhibited in the CE-treated aHSCs. In addition, the CE treatment increased the lipid contents in aHSCs by promoting PPARγ expression. Furthermore, CE modulated the expression of ECM-related genes, i.e., by upregulating MMP-9 and downregulating TIMP-II.

Conclusions

These data revealed that CE could induce the deactivation of aHSCs. We therefore suggest that CE has potential as an adjuvant therapeutic agent against hepatic fibrosis.

The role of osteoprotegerin (OPG) in fibrosis: its potential as a biomarker and/or biological target for the treatment of fibrotic diseases

Fibrosis is defined by excessive formation and accumulation of extracellular matrix proteins, produced by myofibroblasts, that supersedes normal wound healing responses to injury and results in progressive architectural remodelling. Fibrosis is often detected in advanced disease stages when an organ is already severely damaged and can no longer function properly. Therefore, there is an urgent need for reliable and easily detectable markers to identify and monitor fibrosis onset and progression as early as possible; this will greatly facilitate the development of novel therapeutic strategies. Osteoprotegerin (OPG), a well-known regulator of bone extracellular matrix and most studied for its role in regulating bone mass, is expressed in various organs and functions as a decoy for receptor activator of nuclear factor kappa-B ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Recently, OPG has been linked to fibrosis and fibrogenesis, and has been included in a panel of markers to diagnose liver fibrosis. Multiple studies now suggest that OPG may be a general biomarker suitable for detection of fibrosis and/or monitoring the impact of fibrosis treatment. This review summarizes our current understanding of the role of OPG in fibrosis and will discuss its potential as a biomarker and/or novel therapeutic target for fibrosis.

Perivascular stromal cells: Directors of tissue immune niches

Perivascular niches are specialized microenvironments where stromal and immune cells interact with vasculature to monitor tissue status. Adventitial perivascular niches surround larger blood vessels and other boundary sites, supporting collections of immune cells, stromal cells, lymphatics, and neurons. Adventitial fibroblasts (AFs), a subtype of mesenchymal stromal cell, are the dominant constituents in adventitial spaces, regulating vascular integrity while organizing the accumulation and activation of a variety of interacting immune cells. In contrast, pericytes are stromal mural cells that support microvascular capillaries and surround organ-specific parenchymal cells. Here, we outline the unique immune and non-immune composition of perivascular tissue immune niches, with an emphasis on the heterogeneity and immunoregulatory functions of AFs and pericytes across diverse organs. We will discuss how perivascular stromal cells contribute to the regulation of innate and adaptive immune responses and integrate immunological signals to impact tissue health and disease.

Impact of IL10, MTP, SOD2, and APOE Gene Polymorphisms on the Severity of Liver Fibrosis Induced by HCV Genotype 4

Complications of hepatitis C virus (HCV) chronic infection cause ~400,000 deaths worldwide annually. One complication, liver fibrosis, is influenced by host genetic factors. Genes influencing fibrosis include immune, metabolic, oxidative stress, and viral entry genes, such as interleukin 10 (IL10), microsomal triglyceride-transfer protein (MTP), superoxide dismutase-2 (SOD2), and apolipoprotein E (APOE)-encoding genes, respectively. Thus, correlating variations in these genes with HCV-induced fibrosis represents an attractive biomarker for the prognosis of fibrosis severity in chronically infected patients. Here, we aimed to test whether polymorphisms in IL10, MTP, SOD2, and APOE genes correlated with the severity of fibrosis induced by HCV genotype 4 (HCV-gt4) in a cohort of chronically infected Egyptian patients. Our results demonstrate a significant association between the severity of fibrosis and specific SNPs in IL-10, SOD2, and ApoE-encoding genes. Haplotype-combination analysis for IL10, MTP, SOD2, and APOE showed statistically significant associations between specific haplotype combinations and fibrosis severity. Identifying biomarkers correlating with the severity of HCV-gt4-induced fibrosis would significantly impact precision prophylaxis and treatment of patients at risk.

Ligustroflavone ameliorates CCl4-induced liver fibrosis through down-regulating the TGF-β/Smad signaling pathway

Liver fibrosis is a pathological process characterized by excess deposition of extracellular matrix (ECM) that are mainly derived from activated hepatic stellate cells. Previous studies suggested that ligustroflavone (LF) was an ingredient of Ligustrum lucidum Ait. with activities of anti-inflammation and anti-oxidation. In this study, we investigated whether LF had any effect on liver fibrosis. In our study, we established a mouse model of carbon tetrachloride (CCl₄)-induced liver fibrosis and used TGF-β₁-stimulated human hepatic stellate cell line (LX-2) to explore the effect of LF and associated underlying mechanism. LF was used in vivo with low dose (L-LF, 5 mg·kg^-1, i.p., 3 times each week) and high dose (H-LF, 20 mg·kg^-1, i.p., 3 times each week) and in vitro (25 μmol·L^-1). Histopathological and biochemical assays investigations showed that LF delayed the formation of liver fibrosis; decreased AST, ALT activities and increased Alb activity in serum; decreased MDA level, Hyp content and increased GSH-Px concentration, SOD activity in liver tissues. Moreover, immunohistochemical, immunofluorescent and Western blot results showed that LF reduced the expressions of hepatic stellate cells specific marker proteins, including collagen I and α-SMA in vivo and in vitro. In addition, LF markedly suppressed TGF-β₁-upregulated protein expressions of TβR I, TβR II, P-Smad2, P-Smad3 and Smad4 in LX-2 cells. Taken together, these findings demonstrated LF could decrease histopathological lesions, ameliorate oxidative injury, attenuate CCl₄-induced liver fibrosis, which may be associated with down-regulating the TGF-β/Smad signaling pathway.

Regulatory long non-coding RNAs of hepatic stellate cells in liver fibrosis (Review)

Liver fibrosis (LF) is a continuous wound healing process caused by numerous chronic hepatic diseases and poses a major threat to human health. Activation of hepatic stellate cells (HSCs) is a critical event in the development of hepatic fibrosis. Long non-coding RNAs (lncRNAs) that are involved in HSC activation, participate in the development of LF and are likely to be therapeutic targets for LF. In the present review, the cellular signaling pathways of LF with respect to HSCs were discussed. In particular, this present review highlighted the current knowledge on the role of lncRNAs in activating or inhibiting LF, revealing lncRNAs that are likely to be biomarkers or therapeutic targets for LF. Additional studies should be performed to elucidate the potential of lncRNAs in the diagnosis and prognosis of LF and to provide novel therapeutic approaches for the reversion of LF.

MiR-15b and miR-16 suppress TGF-β1-induced proliferation and fibrogenesis by regulating LOXL1 in hepatic stellate cells

Activation of hepatic stellate cells (HSCs) is an important event during the progress of liver fibrosis. MicroRNA (miR)-15b and miR-16 have been found to be involved in activation of HSCs. However, the roles of miR-15b/16 in liver fibrosis remain unclear. The expression of miR-15b/16 was decreased in TGF-β1-stimulated LX-2 cells. Overexpression of miR-15b/16 in LX-2 cells suppressed TGF-β1-induced cell proliferation and the expression levels of tissue inhibitor of metalloproteinase type 1, collagen type I, and α-smooth muscle actin. The activation of Smad2/3 caused by TGF-β1 was repressed by miR-15b/16 overexpression. The two miRNAs directly bound to the 3'-UTR of lysyl oxidase-like 1 (LOXL1) and suppressed the LOXL1 expression. Furthermore, knockdown of LOXL1 attenuated miR-15b/16 downregulation-induced cell proliferation, fibrogenic response and phosphorylation of Smad2/3. Collectively, miR-15b/16 exhibited anti-fibrotic activity through regulation of Smad2/3 pathway.

Mitochondria-targeted curcumin loaded CTPP–PEG–PCL self-assembled micelles for improving liver fibrosis therapy

Liver fibrosis, originating from activated hepatic stellate cells (HSCs), is receiving much attention in the treatment of clinical liver disease. In this study, mitochondria-targeted curcumin (Cur) loaded 3-carboxypropyl-triphenylphosphonium bromide–poly(ethylene glycol)–poly(ε-caprolactone) (CTPP–PEG–PCL) micelles were constructed to prolong the systemic circulation of Cur, improve the bioavailability of Cur and play a precise role in anti-fibrosis. The prepared Cur–CTPP–PEG–PCL micelles with a spherical shape had satisfactory dispersion, low critical micelle concentration (CMC) and high encapsulation efficiency (92.88%). The CTPP modification endowed good endosomal escape ability to the CTPP–PEG–PCL micelles, and micelles could be selectively accumulated in mitochondria, thereby inducing the enhanced cell proliferation inhibition of HSC-T6 cells. Mitochondrial Membrane Potential (MMP) was greatly reduced due to the mitochondrial-targeting of Cur. Moreover, the system circulation of Cur was extended and bioavailability was significantly enhanced in vivo. As expected, Cur loaded CTPP–PEG–PCL micelles were more effective in improving liver fibrosis compared with Cur and Cur–mPEG–PCL micelles. In conclusion, the Cur–CTPP–PEG–PCL based micelles can be a potential candidate for liver fibrosis treatment in future clinical applications.

A mitochondria-targeting micelle system based on CTPP–PEG–PCL polymer was designed to deliver curcumin to active HSC-T6 cells and prolong the systemic circulation and bioavailability of curcumin in vivo for effective treatment of liver fibrosis.

Vitamin D alleviates liver fibrosis by inhibiting histidine-rich calcium binding protein (HRC)

BACKGROUND

Liver fibrosis may progress toward cirrhosis and cancer without effective therapy. Here, we investigated the underlying mechanism of Vitamin D as a therapeutic approach.

METHODS

Carbon tetrachloride (CCL4)-induced mice model and transforming growth factor-β1 (TGF-β1) induced human hepatic stellate cell line LX-2 were used in vivo and in vitro. The fibrotic profiles, degree of liver injury and HRC expression were assessed by histology, Western blot, immunohistochemistry and Real-Time PCR. The proliferation of cells transfected with HRC ^+/+ and HRC^-/- plasmids was detected by MTS and cell cycle methods.

RESULTS

Vitamin D significantly suppressed the expression of HRC in liver fibrosis model both in vivo and in vitro (P < 0.01). The cell with overexpression of HRC significantly increased TGF-β1/Smad3 expressions and the percentage of the S peak in cell cycle (P < 0.05). However, Vitamin D can significantly reverse the levels of TGF-β1, Smad3 and p-smad3 caused by HRC in vitro. Furthermore, the overexpression of HRC in cell lines can attenuate the function of Vitamin D, suggesting that VD played a role by regulating HRC. Mechanically, HRC as the target of VDR is detected by CHIP method.

CONCLUSIONS

Vitamin D can delay hepatic fibrosis by reducing activation of hepatic stellate cells and TGF-β/Smad signaling through negative regulation of HRC. The findings revealed the important regulatory effect of Vitamin D in hepatic stellate cells and provided new insights into the therapeutic function of Vitamin D on liver fibrosis.

Hepatoprotective Potency of Chrysophanol 8-O-Glucoside from Rheum palmatum L. against Hepatic Fibrosis via Regulation of the STAT3 Signaling Pathway

Rhubarb is a well-known herb worldwide and includes approximately 60 species of the Rheum genus. One of the representative plants is Rheum palmatum, which is prescribed as official rhubarb due to its pharmacological potential in the Korean and Chinese pharmacopoeia. In our bioactive screening, we found out that the EtOH extract of R. palmatum inhibited hepatic stellate cell (HSC) activation by transforming growth factor β1 (TGF-β1). Chemical investigation of the EtOH extract led to the isolation of chrysophanol 8-O-glucoside, which was determined by structural analysis using NMR spectroscopic techniques and electrospray ionization mass spectrometry (ESIMS). To elucidate the effects of chrysophanol 8-O-glucoside on HSC activation, activated LX-2 cells were treated for 48 h with chrysophanol 8-O-glucoside, and α-SMA and collagen, HSC activation markers, were measured by comparative quantitative real-time PCR (qPCR) and western blotting analysis. Chrysophanol 8-O-glucoside significantly inhibited the protein and mRNA expression of α-SMA and collagen compared with that in TGF-β1-treated LX-2 cells. Next, the expression of phosphorylated SMAD2 (p-SMAD2) and p-STAT3 was measured and the translocation of p-STAT3 to the nucleus was analyzed by western blotting analysis. The expression of p-SMAD2 and p-STAT3 showed that chrysophanol 8-O-glucoside strongly downregulated STAT3 phosphorylation by inhibiting the nuclear translocation of p-STAT3, which is an important mechanism in HSC activation. Moreover, chrysophanol 8-O-glucoside suppressed the expression of p-p38, not that of p-JNK or p-Erk, which can activate STAT3 phosphorylation and inhibit MMP2 expression, the downstream target of STAT3 signaling. These findings provided experimental evidence concerning the hepatoprotective effects of chrysophanol 8-O-glucoside against liver damage and revealed the molecular basis underlying its anti-fibrotic effects through the blocking of HSC activation.

Epigenetics in Liver Fibrosis: Could HDACs be a Therapeutic Target?

Chronic liver diseases (CLD) represent a worldwide health problem. While CLDs may have diverse etiologies, a common pathogenic denominator is the presence of liver fibrosis. Cirrhosis, the end-stage of CLD, is characterized by extensive fibrosis and is markedly associated with the development of hepatocellular carcinoma. The most important event in hepatic fibrogenesis is the activation of hepatic stellate cells (HSC) following liver injury. Activated HSCs acquire a myofibroblast-like phenotype becoming proliferative, fibrogenic, and contractile cells. While transient activation of HSCs is part of the physiological mechanisms of tissue repair, protracted activation of a wound healing reaction leads to organ fibrosis. The phenotypic changes of activated HSCs involve epigenetic mechanisms mediated by non-coding RNAs (ncRNA) as well as by changes in DNA methylation and histone modifications. During CLD these epigenetic mechanisms become deregulated, with alterations in the expression and activity of epigenetic modulators. Here we provide an overview of the epigenetic alterations involved in fibrogenic HSCs transdifferentiation with particular focus on histones acetylation changes. We also discuss recent studies supporting the promising therapeutic potential of histone deacetylase inhibitors in liver fibrosis.

Tyrosine kinase inhibitor neratinib attenuates liver fibrosis by targeting activated hepatic stellate cells

Liver fibrosis, a common outcome of chronic liver disease characterized by excessive accumulation of extracellular matrix (ECM), is a leading cause of mortality worldwide. The tyrosine kinase inhibitor neratinib is a human epidermal growth factor receptor 2 (HER2) inhibitor approved by the FDA for HER2-positive breast cancer treatment; however, it has not yet been evaluated for liver fibrosis treatment. We elucidated the anti-fibrotic effects of neratinib in hepatic stellate cells (HSCs) and in vivo models of CCl₄-induced liver fibrosis. HSC activation is a key step in liver fibrogenesis and has a crucial role in collagen deposition, as it is primarily responsible for excessive ECM production. The effect of neratinib on HSC was evaluated in transforming growth factor (TGF-β)-incubated LX-2 cells and culture-activated primary human HSCs. In vivo study results indicated that neratinib inhibited the inflammatory response, HSC differentiation, and collagen accumulation induced by CCl₄. Moreover, the anti-fibrotic effects of neratinib were not associated with the HER2 signaling pathways. Neratinib inhibited FGF2 expression in activated HSCs and serum FGF2 level in the model, suggesting that neratinib possessed therapeutic potency against liver fibrosis and the potential for application against other fibrotic diseases.

GNS561 acts as a potent anti-fibrotic and pro-fibrolytic agent in liver fibrosis through TGF-β1 inhibition

Background:

Hepatic fibrosis is the result of chronic liver injury that can progress to cirrhosis and lead to liver failure. Nevertheless, there are no anti-fibrotic drugs licensed for human use. Here, we investigated the anti-fibrotic activity of GNS561, a new lysosomotropic molecule with high liver tropism.

Methods:

The anti-fibrotic effect of GNS561 was determined in vitro using LX-2 hepatic stellate cells (HSCs) and primary human HSCs by studying cell viability, activity of caspases 3/7, autophagic flux, cathepsin maturation and activity, HSC activation and transforming growth factor-β1 (TGF-β1) maturation and signaling. The contribution of GNS561 lysosomotropism to its anti-fibrotic activity was assessed by increasing lysosomal pH. The potency of GNS561 on fibrosis was evaluated in vivo in a rat model of diethylnitrosamine-induced liver fibrosis.

Results:

GNS561 significantly decreased cell viability and promoted apoptosis. Disrupting the lysosomal pH gradient impaired its pharmacological effects, suggesting that GNS561 lysosomotropism mediated cell death. GNS561 impaired cathepsin activity, leading to defective TGF-β1 maturation and autophagic processes. Moreover, GNS561 decreased HSC activation and extracellular matrix deposition by downregulating TGF-β1/Smad and mitogen-activated proteine kinase signaling and inducing fibrolysis. Finally, oral administration of GNS561 (15 mg/kg per day) was well tolerated and attenuated diethylnitrosamine-induced liver fibrosis in this rat model (decrease of collagen deposition and of pro-fibrotic markers and increase of fibrolysis).

Conclusion:

GNS561 is a new potent lysosomotropic compound that could represent a valid medicinal option for hepatic fibrosis treatment through both its anti-fibrotic and its pro-fibrolytic effects. In addition, this study provides a rationale for targeting lysosomes as a promising therapeutic strategy in liver fibrosis.

Byakangelicin protects against carbon tetrachloride-induced liver injury and fibrosis in mice

Liver fibrosis is a disease caused by long-term damage that is related to a number of factors. The current research on the treatment of liver fibrosis mainly focuses on the activation of hepatic stellate cell, in addition to protecting liver cells. byakangelicin has certain anti-inflammatory ability, but its effect on liver fibrosis is unclear. This study aims to explore whether byakangelicin plays a role in the development of liver fibrosis and to explore its mechanism. We determined that byakangelicin has a certain ability to resist fibrosis and reduce liver cell damage in a model of carbon tetrachloride-induced liver fibrosis in mice. Thereafter, we performed further verification in vitro. The signalling pathways of two important pro-fibrotic cytokines, transforming growth factor-β and platelet-derived growth factor, were studied. Results showed that byakangelicin can inhibit related pathways. According to the hepatoprotective effect of byakangelicin observed in animal experiments, we studied the effect of byakangelicin on 4-HNE-induced hepatocyte (HepG2) apoptosis and explored its related pathways. The results showed that byakangelicin could attenuate 4-HNE-induced hepatocyte apoptosis via inhibiting ASK-1/JNK signalling. In conclusion, byakangelicin could improve carbon tetrachloride-induced liver fibrosis and liver injury by inhibiting hepatic stellate cell proliferation and activation and suppressing hepatocyte apoptosis.

Hydralazine Sensitizes to the Antifibrotic Effect of 5-Aza-2'-deoxycytidine in Hepatic Stellate Cells

BACKGROUND

Hepatic stellate cell (HSC) activation is essential for the development of liver fibrosis. Epigenetic machinery, such as DNA methylation, is largely involved in the regulation of gene expression during HSC activation. Although the pharmacological DNA demethylation of HSC using 5-aza-2'-deoxycytidine (5-aza-dC) yielded an antifibrotic effect, this drug has been reported to induce excessive cytotoxicity at a high dose. Hydralazine (HDZ), an antihypertensive agent, also exhibits non-nucleoside demethylating activity. However, the effect of HDZ on HSC activation remains unclear. In this study, we performed a combined treatment with 5-aza-dC and HDZ to obtain an enhanced antifibrotic effect with lower cytotoxicity.

METHODS

HSC-T6 cells were used as a rat HSC cell line in this study. The cells were cultivated together with 1 µM 5-Aza-dC and/or 10 µg/mL of HDZ, which were refreshed every 24 h until the 96 h treatment ended. Cell proliferation was measured using the WST-1 assay. The mRNA expression levels of peptidylprolyl isomerase A (Ppia), an internal control gene, collagen type I alpha 1 (Cola1), RAS protein activator like 1 (Rasal1), and phosphatase and tensin homolog deleted from chromosome 10 (Pten) were analyzed using quantitative reverse transcription polymerase chain reaction.

RESULTS

The percentage cell viability with 5-aza-dC, HDZ, and combined treatment vs. the vehicle-only control was 101.4 ± 2.5, 95.2 ± 5.7, and 79.2 ± 0.7 (p < 0.01 for 5-aza-dC and p < 0.01 for HDZ), respectively, in the 48 h treatment, and 52.4 ± 5.6, 65.9 ± 3.4, and 29.9 ± 1.3 (p < 0.01 for 5-aza-dC and p < 0.01 for HDZ), respectively, in the 96 h treatment. 5-Aza-dC and the combined treatment markedly decreased Cola1 mRNA levels. Accordingly, the expression levels of Rasal1 and Pten, which are antifibrotic genes, were increased by treatment after the 5-aza-dC and combined treatments. Moreover, single treatment with HDZ did not affect the expression levels of Cola1, Rasal1, or Pten. These results suggest that HDZ sensitizes to the antifibrotic effect of 5-aza-dC in HSC-T6 cells. The molecular mechanism underlying the sensitization to the antifibrotic effect of 5-aza-dC by HDZ remains to be elucidated. The expression levels of rat equilibrative nucleoside transporter genes (rEnt1, rEnt2, and rEnt3) were not affected by HDZ in this study.

CONCLUSIONS

Further confirmation using primary HSCs and in vivo animal models is desirable, but combined treatment with 5-aza-dC and HDZ may be an effective therapy for liver fibrosis without severe adverse effects.

Icariin-induced miR-875-5p attenuates epithelial-mesenchymal transition by targeting hedgehog signaling in liver fibrosis

BACKGROUND

Hepatic fibrosis is the final endpoint for most chronic liver diseases and remains a significant public health problem worldwide. Icariin, a naturally occurring flavonol glucoside, has been reported to exhibit protective effects on liver injury and alleviate liver fibrosis. However, the underlying detail molecular mechanism is not fully revealed.

METHODS

Mouse primary hepatic stellate cells (HSCs) and carbon tetrachloride (CCL₄ )-induced liver fibrosis model in mice were used as in vitro and in vivo models in this study. The expression levels of miR-875-5p were detected by quantitative reverse transcription-PCR. The validation of the direct target of miR-875-5p was through dual-luciferase reporter assay and western blotting assay. The cell proliferation and cell mobility were determined using MTT assay and Transwell migration assay, respectively.

RESULTS

We found that icariin inhibited epithelial-mesenchymal transition and collagen protein section of HSCs. Icariin exerted hepatoprotective effects on mice model of CCL₄ -induced liver fibrosis. Our further results revealed that miR-875-5p was downregulated in human cirrhosis tissues and activated murine HSCs. Icariin induced miR-875-5p upregulation and subsequently decreased glioma-associated oncogene homolog 1 (GLI1) expression through direct binding to the three prime untranslated region of GLI1 mRNA.

CONCLUSION

Our study highlighted the potential therapeutic application of icariin for liver fibrosis management.

(-)-Catechin-7-O-β-d-Apiofuranoside Inhibits Hepatic Stellate Cell Activation by Suppressing the STAT3 Signaling Pathway

Hepatic fibrosis is characterized by the abnormal deposition of extracellular matrix (ECM) proteins. During hepatic fibrogenesis, hepatic stellate cell (HSC) activation followed by chronic injuries is considered a key event in fibrogenesis, and activated HSCs are known to comprise approximately 90% of ECM-producing myofibroblasts. Here, we demonstrated that (–)-catechin-7-O-β-d-apiofuranoside (C7A) significantly inhibited HSC activation via blocking the signal transducer and activator of transcription 3 (STAT3) signaling pathway. This is the first study to show the hepatic protective effects of C7A with possible mechanisms in vitro and in vivo. In our bioactivity screening, we figured out that the EtOH extract of Ulmus davidiana var. japonica root barks, which have been used as a Korean traditional medicine, inhibited collagen synthesis in HSCs. Four catechins isolated from the EtOAc fraction of the EtOH extract were compared with each other in terms of reduction in collagen, which is considered as a marker of hepatic protective effects, and C7A showed the strongest inhibitory effects on HSC activation in protein and qPCR analyses. As a possible mechanism, we investigated the effects of C7A on the STAT3 signaling pathway, which is known to activate HSCs. We found that C7A inhibited phosphorylation of STAT3 and translocation of STAT3 to nucleus. C7A also inhibited expressions of MMP-2 and MMP-9, which are downstream genes of STAT3 signaling. Anti-fibrotic effects of C7A were evaluated in a thioacetamide (TAA)-induced liver fibrosis model, which indicated that C7A significantly inhibited ECM deposition through inhibiting STAT3 signaling. C7A decreased serum levels of aspartate amino transferase and alanine transaminase, which were markedly increased by TAA injection. Moreover, ECM-associated proteins and mRNA expression were strongly suppressed by C7A. Our study provides the experimental evidence that C7A has inhibitory effects on HSC activation after live injury and has preventive and therapeutic potentials for the management of hepatic fibrosis.

Synergy of Phospholipid-Drug Formulations Significantly Deactivates Profibrogenic Human Hepatic Stellate Cells

The pivotal role of hepatic stellate cells (HSCs) in orchestrating the bidirectional process of progression and regression of liver fibrosis makes them an ideal target for exploring new antifibrotic therapies. Essential phospholipids (EPLs), with their polyenylphosphatidylcholine (PPC) fraction, either alone or combined with other hepatoprotective substances such as silymarin, are recommended in hepatic impairment, but a scientific rationale for their use is still lacking. Herein, we compared the ability of EPLs to restore quiescent-like features in HSCs with that of dilinoleoylphosphatidylcholine (DLPC), PPC fraction’s main component. Specifically, we screened at the cellular level the antifibrotic effects of PPC formulations in the presence and absence of silymarin, by using LX-2 cells (pro-fibrogenic HSCs) and by assessing the main biochemical hallmarks of the activated and deactivated states of this cell line. We also proved the formulations’ direct effect on the motional order of cell membranes of adherent cells. LX-2 cells, examined for lipid droplets as a quiescence marker, showed that PPCs led to a more prominent deactivation than DLPC. This result was confirmed by a reduction of collagen and α-SMA expression, and by a profound alteration in the cell membrane fluidity. PPC–silymarin formulations deactivated HSCs with a significant synergistic effect. The remarkable bioactivity of PPCs in deactivating fibrogenic HSCs paves the way for the rational design of new therapeutics aimed at managing hepatic fibrosis.

Albumin self-modified liposomes for hepatic fibrosis therapy via SPARC-dependent pathways

Activated hepatic stellate cells (HSCs) have a central role in the progression of liver fibrosis and express a large amount of secreted protein, acidic and rich in cysteine (SPARC), a specific protein-binding protein. In this study, we reported the preparation and evaluation of naringenin (Nar) -loaded albumin self-modified liposomes (NaAlLs), which delivered Nar, a specific Smad3 inhibitor that blocked the TGF-β/Smad3 signaling pathway and played an anti-fibrosis role. After a series of characterization, it was found that NaAlLs had favorable dispersion (PDI < 0.15) with an average particle size of about 120 nm and high entrapment efficiency (>85%), albumin coated the surface of liposomes or embedded in phospholipid bilayer by interaction with the encapsulated naringenin and phospholipid molecules during the preparation of liposomes. The amount of albumin modified to the surface of NaAlLs by this method is not only more than that of the physical adsorption method, but also the binding force between albumin and liposomes is stronger. The albumin modified to the surface of NaAlLs greatly reduced the aggregation of liposomes and drug leakage and increased the stability of liposomes. More importantly, the uptake of NaAlLs by activated HSCs was 1.5 times higher than that of Nar-loaded liposomes (NaLs), suggesting that NaAlLs specifically increased targeting of activated HSCs via albumin and SPARC-dependent pathways. As expected, NaAlLs was more effective in improving liver fibrosis than the NaLs or the inclusion complex solution of Nar and Hydroxypropyl-β-cyclodextrin (NaICS). The results suggested that NaAlLs was a promising drug delivery system, which could target drug delivery to activated HSC for the treatment of liver fibrosis.