Inhibition of EGFR attenuates fibrosis and stellate cell activation in diet-induced model of nonalcoholic fatty liver disease

Current and emerging strategies for the prevention of hepatocellular carcinoma

Liver cancer is the third leading cause of cancer-related deaths globally, with incident cases expected to rise from 905,700 in 2020 to 1.4 million by 2040. Hepatocellular carcinoma (HCC) accounts for about 80% of all primary liver cancers. Viral hepatitis and chronic excessive alcohol consumption are major risk factors for HCC, but metabolic dysfunction-associated steatotic liver disease is also becoming a dominant cause. The increasing numbers of cases of HCC and changes in risk factors highlight the urgent need for updated and targeted prevention strategies. Preventive interventions encompass strategies to decrease the burden of chronic liver diseases and their progression to HCC. These strategies include nutritional interventions and medications that have shown promise in preclinical models. Although prevailing approaches focus on treating chronic liver disease, leveraging a wider range of interventions represents a promising area to safeguard at-risk populations. In this Review, we explore existing evidence for preventive strategies by highlighting established and potential paths to reducing HCC risk effectively and safely, especially in individuals with chronic liver diseases. We categorize the preventive strategies by the mechanism of action, including anti-inflammatory, antihyperglycaemic, lipid-lowering, nutrition and dietary, antiviral, and antifibrotic pathways. For each category, we discuss the efficacy and safety information derived from mechanistic, translational, observational and clinical trial data, pinpointing knowledge gaps and directions for future research.

Liver ALKBH5 regulates glucose and lipid homeostasis independently through GCGR and mTORC1 signaling

Maintaining glucose and lipid homeostasis is crucial for health, with dysregulation leading to metabolic diseases such as type 2 diabetes mellitus (T2DM) and metabolic dysfunction-associated fatty liver disease (MAFLD). This study identifies alkylation repair homolog protein 5 (ALKBH5), an RNA N6-methyladenosine (m6A) demethylase, as a major regulator in metabolic disease. ALKBH5 is up-regulated in the liver during obesity and also phosphorylated by protein kinase A, causing its translocation to the cytosol. Hepatocyte-specific deletion of Alkbh5 reduces glucose and lipids by inhibiting the glucagon receptor (GCGR) and mammalian target of rapamycin complex 1 (mTORC1) signaling pathways. Targeted knockdown of hepatic Alkbh5 reverses T2DM and MAFLD in diabetic mice, highlighting its therapeutic potential. This study unveils a regulatory mechanism wherein ALKBH5 orchestrates glucose and lipid homeostasis by integrating the GCGR and mTORC1 pathways, providing insight into the regulation of metabolic diseases.

Probable targets and mechanism of ginsenoside Rg1 for non-alcoholic fatty liver disease: a study integrating network pharmacology, molecular docking, and molecular dynamics simulation

Ginsenoside Rg1 (GRg1), a key bioactive component of medicinal herbs, has shown beneficial effects on non-alcoholic fatty liver disease (NAFLD) and numerous other conditions. Nevertheless, the specific targets that are actively involved and the potential mechanisms underlying NAFLD treatment remain unclear. This study aimed to elucidate the therapeutic effects and mechanism of GRg1 in alleviating NAFLD using a combined approach of network pharmacology and molecular biology validation. The analysis yielded 294 targets for GRg1 and 1293 associated with NAFLD, resulting in 89 overlapping targets. Through protein-protein interactions (PPI) network topology analysis, 10 key targets were identified. Upon evaluating the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) analysis, GRg1 may exert therapeutic effects on NAFLD by negatively regulating the apoptotic process, insulin and endocrine resistance, the AGE-RAGE signaling pathway in diabetic complications, and the Estrogen, PI3K/Akt, and MAPK pathways. The three differential gene targets for Akt1, EGFR, and IGF1 were identified through the compound-target network in conjunction with the aforementioned methods. The molecular docking and molecular dynamics (MD) simulations showed that AKT1 and EGFR had a strong binding affinity with GRg1. Overall, our findings point to a novel therapeutic strategy involving NAFLD, with further in vivo and in vitro studies promising to deepen our comprehension and validate its potential advantages.Communicated by Ramaswamy H. Sarma.

Methyl donor ameliorates CCl4-induced liver fibrosis by inhibiting inflammation, and fibrosis through the downregulation of EGFR and DNMT-1 expression

Methyl donors regulate the one-carbon metabolism and have significant potential to reduce oxidative stress and inflammation. Therefore, this study aims to investigate the protective effect of methyl donors against CCl4-induced liver fibrosis. Liver fibrosis was induced in male Sprague Dawley rats using CCl4 at a dose of 1 ml/kg (twice a week for a 4-week, via intraperitoneal route). Subsequently, methyl donor treatments were given orally for the next six weeks while continuing CCl4 administration. After 10 weeks, biochemical, histopathology, immunohistochemistry, western blotting, and qRT-PCR were performed. Methyl donor treatment significantly ameliorated ALT, AST, ALP levels, and oxidative stress associated with CCl4-induced liver injury. The histopathological investigation also demonstrated the hepatoprotective effect of methyl donors against CCl4-induced liver fibrosis, showing reduced tissue damage, collagen deposition, and attenuating the expression of the COL1A1 gene. Further, methyl donors inhibited the CCl4-induced increase in DNMT-1 and NF-κB p65 expression with an upregulation of AMPK. Methyl donor downregulated the CCl4-induced increase in inflammatory and fibrosis related gene expression and inhibited the apoptosis with a downregulation of EGFR expression. Here, we provide the first evidence that methyl donor combinations prevent liver fibrosis by attenuating oxidative stress, inflammation, and fibrosis through DNMT-1 and EGFR downregulation.

Lycorine ameliorates liver steatosis, oxidative stress, ferroptosis and intestinal homeostasis imbalance in MASLD mice

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common liver disease worldwide and few drugs are available for its treatment. Lycorine has effective anti-inflammatory and lipid-lowering effects, but the impact on MASLD is not fully understood. In this study, we intend to test the intervention effect of lycorine on MASLD.

METHODS

A MASLD mouse model was constructed on a high-fat diet for 16 weeks, and low, medium, and high doses of lycorine were given by gavage for the last 4 weeks. Detecting indicators related to liver steatosis, oxidative stress, and ferroptosis. In vivo and in vitro experiments co-validate potential targets identified by network pharmacology, molecular docking and western blot for lycorine intervention in MASLD liver. A combination of pathology, western blot, qRT-PCR, and 16 S rRNA sequencing verified adipose tissue and intestinal alterations.

RESULTS

Lycorine ameliorated hepatic steatosis, oxidative stress and ferroptosis in MASLD mice by inhibiting the expression of phosphorylated EGFR, inhibiting the PI3K/AKT signaling pathway. We also observed a dose-dependent effect of lycorine to improve some of the indicators of MASLD. In vitro, knockdown of EGFR significantly attenuated palmitic acid-induced hepatocyte steatosis. In addition, lycorine promoted WAT browning for thermogenesis and energy consumption, affected the composition of intestinal flora, improved the intestinal barrier, and reduced intestinal inflammation.

CONCLUSIONS

EGFR was the target of lycorine intervention in MASLD. Lycorine ameliorated hepatic steatosis, oxidative stress and ferroptosis by affecting the EGFR/PI3K/AKT signaling pathway in MASLD mice. Furthermore, lycorine promoted WAT browning and ameliorated intestinal homeostatic imbalance. The above effects may also have dose-dependent effects.

Chlorogenic acid attenuates idiopathic pulmonary fibrosis: An integrated analysis of network pharmacology, molecular docking, and experimental validation

AIMS

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung condition, the cause of which remains unknown and for which no effective therapeutic treatment is currently available. Chlorogenic acid (CGA), a natural polyphenolic compound found in different plants and foods, has emerged as a promising agent due to its anti-inflammatory, antioxidant, and antifibrotic properties. However, the molecular mechanisms underlying the therapeutic effect of CGA in IPF remain unclear. The purpose of this study was to analyze the pharmacological impact and underlying mechanisms of CGA in IPF.

MAIN METHODS

Using network pharmacology analysis, genes associated with IPF and potential molecular targets of CGA were identified through specialized databases, and a protein-protein interaction (PPI) network was constructed. Molecular docking was performed to accurately select potential therapeutic targets. To investigate the effects of CGA on lung histology and key gene expression, a murine model of bleomycin-induced lung fibrosis was used.

KEY FINDINGS

Network pharmacology analysis identified 384 were overlapped between CGA and IPF. Key targets including AKT1, TP53, JUN, CASP3, BCL2, MMP9, NFKB1, EGFR, HIF1A, and IL1B were identified. Pathway analysis suggested the involvement of cancer, atherosclerosis, and inflammatory processes. Molecular docking confirmed the stable binding between CGA and targets. CGA regulated the expression mRNA of EGFR, MMP9, AKT1, BCL2 and IL1B and attenuated pulmonary fibrosis in the mouse model.

SIGNIFICANCE

CGA is a promising multi-target therapeutic agent for IPF, which is supported by its efficacy in reducing fibrosis through the modulation of key pathways. This evidence provides a basis to further investigate CGA as an IPF potential treatment.

IGFBP2 functions as an endogenous protector against hepatic steatosis via suppression of the EGFR-STAT3 pathway

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is deemed as an emerging global epidemic, whereas the underlying pathogenic mechanism remains to be clarified. We aimed to systemically analyze all the NAFLD-related gene expression datasets from published human-based studies, by which exploring potential key factors and mechanisms accounting for the pathogenesis of NAFLD.

METHODS

Robust rank aggregation (RRA) method was used to integrate NAFLD-related gene expression datasets. For fatty liver study, adeno-associated virus (AAV) delivery and genetic knockout mice were used to create IGFBP2 (Insulin-like growth factor binding protein 2) gain- or loss-of function models. Western blot, Co-immunoprecipitation (Co-IP), immunofluorescent (IF) staining, luciferase assay, molecular docking simulation were performed to reveal the IGFBP2-EGFR-STAT3 axis involved. Key axis protein levels in livers from healthy donors and patients with NAFLD were assessed via immunohistochemical staining.

RESULTS

By using RRA method, the present study identified IGFBP2 being the most significantly down-regulated gene in all NAFLD subjects. The decreased IGFBP2 expression was further confirmed in the liver tissues from patients and animal models of NAFLD. IGFBP2 deficiency aggravated hepatic steatosis and NASH phenotypes and promoted lipogenic gene expression both in vivo and in vitro. Mechanistically, IGFBP2 directly binds to and regulates EGFR, whereas blockage of the IGFBP2-EGFR complex by knockdown of IGFBP2 resulted in the EGFR-STAT3 pathway activation, which in turn promoted the promoter activity of Srebf1. By using molecular docking simulation and protein-protein interaction analysis, the sequence of 233-257 amino acids in IGFBP2 was characterized as a key motif responding for its specific binding to EGFR and the protective effect against hepatic steatosis.

CONCLUSIONS

The current study has, for the first time, identified IGFBP2 as a novel protector against hepatosteatosis. The protective effect is mediated by its specific interaction with EGFR and thereby suppressing the EGFR-STAT3 pathway. Therefore, pharmaceutically targeting the IGFBP2-EGFR-STAT3 axis may provide a theoretical basis for for the treatment of NAFLD/NASH and the associated diseases.

m6A epitranscriptomic and epigenetic crosstalk in liver fibrosis: Special emphasis on DNA methylation and non-coding RNAs

Liver fibrosis is a pathological process caused by a variety of chronic liver diseases. Currently, therapeutic options for liver fibrosis are very limited, highlighting the urgent need to explore new treatment approaches. Epigenetic modifications and epitranscriptomic modifications, as reversible regulatory mechanisms, are involved in the development of liver fibrosis. In recent years, researches in epitranscriptomics and epigenetics have opened new perspectives for understanding the pathogenesis of liver fibrosis. Exploring the epigenetic mechanisms of liver fibrosis may provide valuable insights into the development of new therapies for chronic liver diseases. This review primarily focus on the regulatory mechanisms of N6-methyladenosine (m6A) modification, non-coding RNA, and DNA methylation in organ fibrosis. It discusses the interactions between m6A modification and DNA methylation, as well as between m6A modification and non-coding RNA, providing a reference for understanding the interplay between epitranscriptomics and epigenetics.

The hepatocyte epidermal growth factor receptor (EGFR) pathway regulates the cellular interactome within the liver fibrotic niche

Liver fibrosis is the consequence of chronic liver injury in the presence of an inflammatory component. Although the main executors of this activation are known, the mechanisms that lead to the inflammatory process that mediates the production of pro-fibrotic factors are not well characterized. Epidermal growth factor receptor (EGFR) signaling in hepatocytes is essential for the regenerative processes of the liver; however, its potential role in regulating the fibrotic niche is not yet clear. Our group generated a mouse model that expresses an inactive truncated form of the EGFR specifically in hepatocytes (ΔEGFR mice). Here, we have analyzed the response of WT and ΔEGFR mice to chronic treatment with carbon tetrachloride (CCl4), which induces a pro-inflammatory and fibrotic process in the liver. The results indicated that the hallmarks of liver fibrosis were attenuated in CCl4-treated ΔEGFR mice when compared with CCl4-treated WT mice, coinciding with a faster resolution of the fibrotic process and ameliorated damage. The absence of EGFR activity in hepatocytes induced changes in the pattern of immune cells in the liver, with a notable increase in the population of M2 macrophages, more related to fibrosis resolution, as well as in the population of lymphocytes related to eradication of the damage. Transcriptome analysis of hepatocytes, and secretome studies of extracellular media from in vitro experiments, allowed us to elucidate the specific molecular mechanisms regulated by EGFR that mediate hepatocyte production of both pro-fibrotic and pro-inflammatory mediators; these have consequences for the deposition of extracellular matrix proteins, as well as for the immune microenvironment. Overall, our study uncovered novel mechanistic insights regarding EGFR kinase-dependent actions in hepatocytes that reveal its key role in chronic liver damage. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Hepatocyte-specific Epidermal Growth Factor Receptor Deletion Promotes Fibrosis but has no Effect on Steatosis in Fast-food Diet Model of Metabolic Dysfunction-associated Steatotic Liver Disease

BACKGROUND & AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become the most prevalent chronic liver disorder, with no approved treatment. Our previous work demonstrated the efficacy of a pan-ErbB inhibitor, Canertinib, in reducing steatosis and fibrosis in a murine fast-food diet (FFD) model of MASLD. The current study explores the effects of hepatocyte-specific ErbB1 (ie, epidermal growth factor receptor [EGFR]) deletion in the FFD model.

METHODS

EGFRflox/flox mice, treated with AAV8-TBG-CRE to delete EGFR specifically in hepatocytes (EGFR-KO), were fed either a chow-diet or FFD for 2 or 5 months.

RESULTS

Hepatocyte-specific EGFR deletion reduced serum triglyceride levels but did not prevent steatosis. Surprisingly, hepatic fibrosis was increased in EGFR-KO mice in the long-term study, which correlated with activation of transforming growth factor-β/fibrosis signaling pathways. Further, nuclear levels of some of the major MASLD regulating transcription factors (SREBP1, PPARγ, PPARα, and HNF4α) were altered in FFD-fed EGFR-KO mice. Transcriptomic analysis revealed significant alteration of lipid metabolism pathways in EGFR-KO mice with changes in several relevant genes, including downregulation of fatty-acid synthase and induction of lipolysis gene, Pnpla2, without impacting overall steatosis. Interestingly, EGFR downstream signaling mediators, including AKT, remain activated in EGFR-KO mice, which correlated with increased activity pattern of other receptor tyrosine kinases, including ErbB3/MET, in transcriptomic analysis. Lastly, Canertinib treatment in EGFR-KO mice, which inhibits all ErbB receptors, successfully reduced steatosis, suggesting the compensatory roles of other ErbB receptors in supporting MASLD without EGFR.

CONCLUSIONS

Hepatocyte-specific EGFR-KO did not impact steatosis, but enhanced fibrosis in the FFD model of MASLD. Gene networks associated with lipid metabolism were greatly altered in EGFR-KO, but phenotypic effects might be compensated by alternate signaling pathways.

Quinoa Polyphenol Extract Alleviates Non-Alcoholic Fatty Liver Disease via Inhibiting Lipid Accumulation, Inflammation and Oxidative Stress

Recently, the incidence of NAFLD has exploded globally, but there are currently no officially approved medications for treating the condition. The regulation of NAFLD through plant-derived active substances has become a new area of interest. Quinoa (Chenopodium quinoa Willd.) has been discovered to contain a large quantity of bioactive compounds. In this study, we established a free fatty acid (FFA)-induced steatosis model and explored the effects of quinoa polyphenol extract (QPE) on the major hallmarks of NAFLD. The results indicated that QPE significantly reduced intracellular triglyceride (TG) and total cholesterol (TC) levels. Additionally, QPE remarkably elevated the levels of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) and lowered levels of malondialdehyde (MDA). Further examination revealed that QPE attenuated intracellular inflammation, which was verified by the reduced levels of pro-inflammatory cytokines. Mechanistically, QPE inhibited fatty acid biosynthesis mainly by targeting de novo lipogenesis (DNL) via the AMPK/SREBP-1c signaling pathway. Moreover, network pharmacology was used to analyze key targets for NAFLD mitigation by ferulic acid (FA), a major component of QPE. Taken together, this study suggests that QPE could ameliorate NAFLD by modulating hepatic lipid metabolism and alleviating oxidative stress and inflammation.

Evaluation of the modulating effect of epidermal growth factor receptor inhibitor cetuximab in carbon-tetrachloride induce hepatic fibrosis in rats

Liver fibrosis, developed in almost all chronic liver injuries. Epidermal growth factor receptors (EGFR) have been thought to contribute to cirrhosis and liver fibrosis. Therefore, using a rat model of carbon tetrachloride (CCl4)-induced liver fibrogenesis, we investigated the preventive effects of cetuximab, an inhibitor of the EGF receptor (EGFR). Ameliorative effects of cetuximab were examined in rats, brought on by biweekly doses of 50 mg/kg of carbon tetrachloride (CCl4). There were a total of 24 male Long Evans rats split up into four distinct groups such as control, CCl4, control+cetuximab and CCl4+cetuximab. After two weeks of treatment with cetuximab (100 μg/kg), samples of tissue and blood were taken after all the rats had been sacrificed. Plasma samples were examined for the biochemical indicators of inflammation and oxidative stress. Histological staining on liver sections was performed for morphologic pathologies, and related genes expressions analysis were done with RT-PCR in liver tissue. The findings showed that cetuximab could raise the levels of glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) and considerably lower the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), malondialdehyde (MDA), and nitric oxide (NO). Sirius red staining and hematoxylin-eosin (H&E) displayed that cetuximab therapy reduced the inflammatory cells infiltration and enhanced fibrotic lesions. In the meantime, cetuximab therapy also dramatically reduces the expression of genes linked to inflammation in the liver tissue, including NF-кB, iNOS, IL-6, TNF-α, and TGF-β. To sum up, the anti-inflammatory, antifibrotic, and antioxidant properties of cetuximab confer curative efficacy against liver fibrosis.

Unmet needs in the post-direct-acting antivirals era: The risk and molecular mechanisms of hepatocellular carcinoma after hepatitis C virus eradication

Hepatitis C virus (HCV) infection is one of the major etiologies of hepatocellular carcinoma (HCC) with approximately 30% of HCC being due to HCV infection worldwide. HCV eradication by antivirals greatly reduces the risk of HCC; nevertheless, HCC remains to occur in chronic hepatitis C (CHC) patients who have achieved a sustained virological response (SVR). The proportion of post-SVR HCC among newly diagnosed HCC patients is increasing in the direct-acting antiviral (DAA) era and might be due to preexisting inflammatory and fibrotic liver backgrounds, immune dysregulation between host and virus interactions, as well as host epigenetic scars, genetic predispositions and alternations. By means of applying surrogate markers and adopting risk stratification, HCC surveillance should be consistently performed in high-risk populations. In this review, we discuss the possible molecular mechanism, risk factors, and HCC surveillance strategy for HCC development after HCV eradication in CHC patients.

Hepatocellular RECK as a Critical Regulator of Metabolic Dysfunction-associated Steatohepatitis Development

BACKGROUND & AIMS

Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) is an extracellular matrix regulator with anti-fibrotic effects. However, its expression and role in metabolic dysfunction-associated steatohepatitis (MASH) and hepatic fibrosis are poorly understood.

METHODS

We generated a novel transgenic mouse model with RECK overexpression specifically in hepatocytes to investigate its role in Western diet (WD)-induced liver disease. Proteomic analysis and in vitro studies were performed to mechanistically link RECK to hepatic inflammation and fibrosis.

RESULTS

Our results show that RECK expression is significantly decreased in liver biopsies from human patients diagnosed with MASH and correlated negatively with severity of metabolic dysfunction-associated steatotic liver disease (MASLD) and fibrosis. Similarly, RECK expression is downregulated in WD-induced MASH in wild-type mice. Hepatocyte-specific RECK overexpression significantly reduced hepatic pathology in WD-induced liver injury. Proteomic analysis highlighted changes in extracellular matrix and cell-signaling proteins. In vitro mechanistic studies linked RECK induction to reduced ADAM10 (a disintegrin and metalloproteinase domain-containing protein 10) and ADAM17 activity, amphiregulin release, epidermal growth factor receptor activation, and stellate cell activation.

CONCLUSION

Our in vivo and mechanistic in vitro studies reveal that RECK is a novel upstream regulator of inflammation and fibrosis in the diseased liver, its induction is hepatoprotective, and thus highlights its potential as a novel therapeutic in MASH.

Cytoplasmic retention of the DNA/RNA-binding protein FUS ameliorates organ fibrosis in mice

Uncontrolled accumulation of extracellular matrix leads to tissue fibrosis and loss of organ function. We previously demonstrated in vitro that the DNA/RNA-binding protein fused in sarcoma (FUS) promotes fibrotic responses by translocating to the nucleus, where it initiates collagen gene transcription. However, it is still not known whether FUS is profibrotic in vivo and whether preventing its nuclear translocation might inhibit development of fibrosis following injury. We now demonstrate that levels of nuclear FUS are significantly increased in mouse models of kidney and liver fibrosis. To evaluate the direct role of FUS nuclear translocation in fibrosis, we used mice that carry a mutation in the FUS nuclear localization sequence (FUSR521G) and the cell-penetrating peptide CP-FUS-NLS that we previously showed inhibits FUS nuclear translocation in vitro. We provide evidence that FUSR521G mice or CP-FUS-NLS-treated mice showed reduced nuclear FUS and fibrosis following injury. Finally, differential gene expression analysis and immunohistochemistry of tissues from individuals with focal segmental glomerulosclerosis or nonalcoholic steatohepatitis revealed significant upregulation of FUS and/or collagen genes and FUS protein nuclear localization in diseased organs. These results demonstrate that injury-induced nuclear translocation of FUS contributes to fibrosis and highlight CP-FUS-NLS as a promising therapeutic option for organ fibrosis.

Linking fatty liver diseases to hepatocellular carcinoma by hepatic stellate cells

Hepatic stellate cells (HSCs), a distinct category of non-parenchymal cells in the liver, are critical for liver homeostasis. In healthy livers, HSCs remain non-proliferative and quiescent. However, under conditions of acute or chronic liver damage, HSCs are activated and participate in the progression and regulation of liver diseases such as liver fibrosis, cirrhosis, and liver cancer. Fatty liver diseases (FLD), including nonalcoholic (NAFLD) and alcohol-related (ALD), are common chronic inflammatory conditions of the liver. These diseases, often resulting from multiple metabolic disorders, can progress through a sequence of inflammation, fibrosis, and ultimately, cancer. In this review, we focused on the activation and regulatory mechanism of HSCs in the context of FLD. We summarized the molecular pathways of activated HSCs (aHSCs) in mediating FLD and their role in promoting liver tumor development from the perspectives of cell proliferation, invasion, metastasis, angiogenesis, immunosuppression, and chemo-resistance. We aimed to offer an in-depth discussion on the reciprocal regulatory interactions between FLD and HSC activation, providing new insights for researchers in this field.

Perinatal triphenyl phosphate exposure induces metabolic dysfunctions through the EGFR/ERK/AKT signaling pathway: Mechanistic in vitro and in vivo studies

Triphenyl phosphate (TPhP), a widely used organophosphate-flame retardant, is ubiquitously found in household environments and may adversely affect human health. Evidence indicates that TPhP exposure causes metabolic dysfunctions in vivo; however, the underlying mechanism of such adverse effects has not been comprehensively investigated. Herein, we utilized two in vitro models including mouse and human preadipocytes to delineate adipogenic mechanisms of TPhP. The results revealed that both mouse and human preadipocytes exposed to TPhP concentration-dependently accumulated more fat through a significant upregulation of epidermal growth factor receptor (EGFR). We demonstrated that TPhP significantly promoted adipogenesis through the activation of EGFR/ERK/AKT signaling pathway as evident by a drastic reduction in adipogenesis of preadipocytes cotreated with inhibitors of EGFR and its major effectors. Furthermore, we confirmed the mechanism of TPhP-induced metabolic dysfunctions in vivo. We observed that male mice perinatally exposed to TPhP had a significant increase in adiposity, hepatic triglycerides, insulin resistance, plasma insulin levels, hypotension, and phosphorylated EGFR in gonadal fat. Interestingly, an administration of a potent and selective EGFR inhibitor significantly ameliorated the adverse metabolic effects caused by TPhP. Our findings uncovered a potential mechanism of TPhP-induced metabolic dysfunctions and provided implications on toxic metabolic effects posed by environmental chemicals.

Machine learning identifies ferroptosis-related gene ANXA2 as potential diagnostic biomarkers for NAFLD

Introduction

Non-alcoholic fatty liver disease (NAFLD), a major cause of chronic liver disease, still lacks effective therapeutic targets today. Ferroptosis, a type of cell death characterized by lipid peroxidation, has been linked to NAFLD in certain preclinical trials, yet the exact molecular mechanism remains unclear. Thus, we analyzed the relationship between ferroptosis genes and NAFLD using high-throughput data.

Method

We utilized a total of 282 samples from five datasets, including two mouse ones, one human one, one single nucleus dataset and one single cell dataset from Gene Expression Omnibus (GEO), as the data basis of our study. To filter robust treatment targets, we employed four machine learning methods (LASSO, SVM, RF and Boruta). In addition, we used an unsupervised consensus clustering algorithm to establish a typing scheme for NAFLD based on the expression of ferroptosis related genes (FRGs). Our study is also the first to investigate the dynamics of FRGs throughout the disease process by time series analysis. Finally, we validated the relationship between core gene and ferroptosis by in vitro experiments on HepG2 cells.

Results

We discovered ANXA2 as a central focus in NAFLD and indicated its potential to boost ferroptosis in HepG2 cells. Additionally, based on the results obtained from time series analysis, ANXA2 was observed to significantly define the disease course of NAFLD. Our results demonstrate that implementing a ferroptosis-based staging method may hold promise for the diagnosis and treatment of NAFLD.

Conclusion

Our findings suggest that ANXA2 may be a useful biomarker for the diagnosis and characterization of NAFLD.

Potential Hepatoprotective Effects of Chamaecyparis lawsoniana against Methotrexate-Induced Liver Injury: Integrated Phytochemical Profiling, Target Network Analysis, and Experimental Validation

Methotrexate (MTX) therapy encounters significant limitations due to the significant concern of drug-induced liver injury (DILI), which poses a significant challenge to its usage. To mitigate the deleterious effects of MTX on hepatic function, researchers have explored plant sources to discover potential hepatoprotective agents. This study investigated the hepatoprotective effects of the ethanolic extract derived from the aerial parts of Chamaecyparis lawsoniana (CLAE) against DILI, specifically focusing on MTX-induced hepatotoxicity. UPLC-ESI-MS/MS was used to identify 61 compounds in CLAE, with 31 potential bioactive compounds determined through pharmacokinetic analysis. Network pharmacology analysis revealed 195 potential DILI targets for the bioactive compounds, including TP53, IL6, TNF, HSP90AA1, EGFR, IL1B, BCL2, and CASP3 as top targets. In vivo experiments conducted on rats with acute MTX-hepatotoxicity revealed that administering CLAE orally at 200 and 400 mg/kg/day for ten days dose-dependently improved liver function, attenuated hepatic oxidative stress, inflammation, and apoptosis, and reversed the disarrayed hepatic histological features induced by MTX. In general, the findings of the present study provide evidence in favor of the hepatoprotective capabilities of CLAE in DILI, thereby justifying the need for additional preclinical and clinical investigations.

Recent Updates on the Therapeutic Prospects of Reversion-Inducing Cysteine-Rich Protein with Kazal Motifs (RECK) in Liver Injuries

The reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a membrane-anchored glycoprotein, negatively regulates various membrane proteins involved in the tissue governing extracellular matrix (ECM) remodeling such as metalloproteases (MMPs) and the sheddases ADAM10 and ADAM17. The significance of the present review is to summarize the current understanding of the pathophysiological role of RECK, a newly discovered signaling pathway associated with different liver injuries. Specifically, this review analyzes published data on the downregulation of RECK expression in hepatic ischemia/reperfusion (I/R) injury, liver-related cancers, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), as well as in the progression of nonalcoholic fatty liver disease (NAFLD) to non-alcoholic steatohepatitis (NASH). In addition, this review discusses the regulation of RECK by inducers, such as FXR agonists. The RECK protein has also been suggested as a potential diagnostic and prognostic marker for liver injury or as a biomarker with predictive value for drug treatment efficacy.

Effects of glyphosate exposure on western diet-induced non-alcoholic fatty liver disease in mice

We evaluated whether glyphosate promotes western diet (WD)-induced non-alcoholic fatty liver disease (NAFLD). Male C57BL/6J mice were fed WD and received intragastrical glyphosate (0.05, 5 or 50 mg/kg) for 6 months. Glyphosate did not promote WD-induced obesity, hypercholesterolemia, glucose intolerance, hepatic steatosis, and fibrosis. Nonetheless, the higher dose (50 mg) enhanced hepatic CD68+ macrophage density, p65, TNF-α, and IL-6 protein levels. Furthermore, this dose decreased hepatic Nrf2 levels, while enhancing lipid peroxidation in the liver and adipose tissue. Hepatic transcriptome revealed that glyphosate at 50 mg upregulated 212 genes and downregulated 731 genes. Genes associated with oxidative stress and inflammation were upregulated, while key cell cycle-related genes were downregulated. Our results indicate that glyphosate exposure - in a dose within the toxicological limits - impairs hepatic inflammation/redox dynamics in a NAFLD microenvironment.

Hepatic stellate cell-intrinsic role of SOCS1 in controlling hepatic fibrogenic response and the pro-inflammatory macrophage compartment during liver fibrosis

Introduction

Hepatic stellate cells (HSC) become activated, differentiate to myofibroblasts and produce extracellular fibrillar matrix during liver fibrosis. The hepatic fibrogenic response is orchestrated by reciprocal interactions between HSCs and macrophages and their secreted products. SOCS1 can regulate several cytokines and growth factors implicated in liver fibrosis. Here we investigated the role of SOCS1 in regulating HSC activation.

Methods

Mice lacking SOCS1 in HSCs (Socs1ΔHSC) were generated by crossing Socs1fl/fl and LratCre mice. Liver fibrosis was induced by carbon tetrachloride and evaluated by Sirius red staining, hydroxyproline content and immunostaining of myofibroblasts. Gene expression of pro-fibrogenic factors, cytokines, growth factors and chemokines were quantified by RT-qPCR. The phenotype and the numbers of intrahepatic leukocyte subsets were studied by flow cytometry. The impact of fibrosis on the development of diethyl nitrosamine-induced hepatocellular carcinoma was evaluated.

Results

Socs1ΔHSC mice developed more severe liver fibrosis than control Socs1fl/fl mice that was characterized by increased collagen deposition and myofibroblast differentiation. Socs1ΔHSC mice showed a significant increase in the expression of smooth muscle actin, collagens, matrix metalloproteases, cytokines, growth factors and chemokines in the liver following fibrosis induction. The fibrotic livers of Socs1ΔHSC mice displayed heightened inflammatory cell infiltration with increased proportion and numbers of Ly6ChiCCR2+ pro-inflammatory macrophages. This macrophage population contained elevated numbers of CCR2+CX3CR1+ cells, suggesting impaired transition towards restorative macrophages. Fibrosis induction following exposure to diethyl nitrosamine resulted in more numerous and larger liver tumor nodules in Socs1ΔHSC mice than in Socs1fl/fl mice.

Discussion

Our findings indicate that (i) SOCS1 expression in HSCs is a critical to control liver fibrosis and development of hepatocaellular carcinoma, and (ii) attenuation of HSC activation by SOCS1 regulates pro-inflammatory macrophage recruitment and differentiation during liver fibrosis.

Integrating inflammatory biomarker analysis and artificial-intelligence-enabled image-based profiling to identify drug targets for intestinal fibrosis

Intestinal fibrosis, often caused by inflammatory bowel disease, can lead to intestinal stenosis and obstruction, but there are no approved treatments. Drug discovery has been hindered by the lack of screenable cellular phenotypes. To address this, we used a scalable image-based morphology assay called Cell Painting, augmented with machine learning algorithms, to identify small molecules that could reverse the activated fibrotic phenotype of intestinal myofibroblasts. We then conducted a high-throughput small molecule chemogenomics screen of approximately 5,000 compounds with known targets or mechanisms, which have achieved clinical stage or approval by the FDA. By integrating morphological analyses and AI using pathologically relevant cells and disease-relevant stimuli, we identified several compounds and target classes that are potentially able to treat intestinal fibrosis. This phenotypic screening platform offers significant improvements over conventional methods for identifying a wide range of drug targets.

Network Pharmacology and Molecular Docking Reveal the Mechanism of Isodon ternifolius (D. Don) Kudo Against Liver Fibrosis

Aim

Many studies have demonstrated the hepatoprotective or anti-fibrotic effects of Isodon ternifolius, but its pharmacological basis and mechanism remain unclear. In this study, we used in vitro models to validate the predicted results and revealed the potential mechanism of action and active ingredients through network pharmacology methods and molecular docking.

Methods

The chemical components of Isodon ternifolius were identified by literatures. Potential targets of Isodon ternifolius were predicted by Swiss Target Prediction. The disease targets were collected through the databases of Gene Card. Common targets of Isodon ternifolius and liver fibrosis were obtained by online tool Venny 2.1. PPI protein interaction network was obtained using String database, and target protein interaction network was drawn using Cytoscape software. Signaling pathway enrichment analysis was performed on drug-disease targets with of DAVID database.

Results

Twenty-one potential active ingredients and 298 potential targets were predicted by Swiss Target Prediction platform. Ninety pathways related to liver fibrosis were obtained by KEGG enrichment. The TLR4, MAPK and PI3K-Akt signaling pathways are mostly associated with liver fibrosis. Molecular docking techniques were used to validate the core target proteins TNF, Akt1, MAPK1, EGFR and TLR4 binding to the ingredients of Isodon ternifolius, which showed that a multitude of ingredients of Isodon ternifolius were able to bind to the above target proteins, especially 2α-hydroxy oleanolic acid and (-)-Lambertic acid. Our experimental validation results showed that Isodon ternifolius inhibited the activation of PI3K-Akt and ERK1/2 signaling pathways.

Conclusion

Through a network pharmacology approach and in vitro cell assay, we predicted and validated the active compounds of Isodon ternifolius and its potential targets for LF treatment. The results suggest that the mechanism of Isodon ternifolius treating LF by inhibiting angiogenesis may be related to the ERK1/2 and PI3K/Akt signaling pathways.

Emerging roles of tyrosine kinases in hepatic inflammatory diseases and therapeutic opportunities

Inflammation has been convicted of causing and worsening many liver diseases like acute liver failure, fibrosis, cirrhosis, fatty liver and liver cancer. Pattern recognition receptors (PRRs) like TLRs 4 and 9 localized on resident or recruited immune cells are well known cellular detectors of pathogen and damage-associated molecular patterns (PAMPs/DAMPs). Stimulation of these receptors generates the sterile and non-sterile inflammatory responses in the liver. When these responses are repeated, there will be a sustained liver injury that may progress to fibrosis and its outcomes. Crosstalk between inflammatory/fibrogenic-dependent streams and certain tyrosine kinases (TKs) has recently evolved in the context of hepatic diseases. Because of TKs increasing importance, their role should be elucidated to highlight effective approaches to manage the diverse liver disorders. This review will give a brief overview of types and functions of some TKs like BTK, JAKs, Syk, PI3K, Src and c-Abl, as well as receptors for TAM, PDGF, EGF, VEGF and HGF. It will then move to discuss the roles of these TKs in the regulation of the proinflammatory, fibrogenic and tumorigenic responses in the liver. Lastly, the therapeutic opportunities for targeting TKs in hepatic inflammatory disorders will be addressed. Overall, this review sheds light on the diverse TKs that have substantial roles in hepatic disorders and potential therapeutics modulating their activity.

Epidermal growth factor receptor promotes high-fructose nonalcoholic fatty liver disease by inducing mitochondrial fission in zebrafish

Mitochondrial function has a pivotal role in the pathogenesis of NAFLD. Mitochondrial dynamics is a foundational activity underlying the maintenance of mitochondrial function in bioenergetics, the maintenance of MtDNA, calcium homeostasis, reactive oxygen species metabolism, and quality control. Loss of mitochondrial plasticity in terms of functions, morphology and dynamics may also be the critical switch from NAFLD/NASH to HCC. However, the cause of mitochondrial fission in NAFLD remains unclear. Recent studies have reported that EGFR can bind to Mfn1 and interfere with its polymerization. In this study, we investigated whether EGFR binds to Mfn1 in NAFLD, and whether reducing their binding can improve NAFLD in zebrafish model. Our results demonstrated that EGFR was activated in hepatocytes from high fructose (HF)-induced NAFLD zebrafish and interfered with Mfn1 polymerization, leading to reduction of MtDNA. Suppression of EGFR activation or mitochondrial translocation significantly improved mitochondrial morphology and increased mitochondrial DNA, ultimately preventing hepatic steatosis. In conclusion, these results suggest that EGFR binding to Mfn1 plays an important role in NAFLD zebrafish model and that inhibition of their binding could be a potential therapeutic target.

Investigation on the mechanism of Ginkgo Folium in the treatment of Non-alcoholic Fatty Liver Disease by strategy of network pharmacology and molecular docking

BACKGROUND

Ginkgo Folium has a favorable effect on non-alcoholic fatty live disease (NAFLD), but its mechanism remains unclear.

OBJECTIVE

The aim of this study is to reveal the underlying mechanism of Ginkgo Folium in the treatment of NAFLD.

METHODS

Ingredients of Ginkgo Folium and ingredients-related genes were collected from TCMSP database and SwissTargetPrediction website, respectively. Genecards database was used to obtain NAFLD-related genes. Next, the protein-protein interaction network and key ingredients-genes network were constructed via Cytoscape3.7.0. Based on the Metascape website, gene ontology function analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were carried out for key genes. Finally, molecular docking was performed to present the interaction between components and genes using AutoDock Vina 1.1.2.

RESULTS

Eighteen active ingredients and 10 target genes were screened from Ginkgo Folium. AKT1, TNF, EGFR, PTGS2, MAPK8, PPAγ, APP, ESR1, HIFα and PPAα were considered as potential therapeutic targets. These target genes were mainly enriched in insulin resistance, HIF-1, adipocytokine and AMPK signaling pathways. Molecular docking results suggested that Ginkgo Folium active ingredients including luteolin-4'-glucoside, sesamin, luteolin, chryseriol, isorhamnetin and laricitrin showed strong binding capacities with AKT1.

CONCLUSION

The study showed that multi-components in Ginkgo Folium interacted with AKT1 and regulated AKT-AMPK/HIF pathway to alleviate NAFLD. Our findings provided an essential role and basis for new anti-NAFLD drug discovery and further research on Ginkgo Folium.

Huangqin decoction mitigates hepatic inflammation in high-fat diet-challenged rats by inhibiting TLR4/NF-κB/NLRP3 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic hepatopathy worldwide, in which ectopic steatosis (5%) and inflammatory infiltration in the liver are the principal clinical characteristics. Huangqin decoction (HQD), a Chinese medicine formula used in the clinic for thousands of years, presents appreciable anti-inflammatory effects. Nevertheless, the role and mechanism of HQD against inflammation in NAFLD are still undefined.

AIM OF THE STUDY

The objective of this study was to evaluate the curative efficacy and unravel the involved mechanism of HQD on a high-fat diet (HFD)-induced NAFLD.

MATERIALS AND METHODS

First, HPLC was utilized to analyze the main chemical components of HQD. Then, NAFLD model was introduced by subjecting the rats to HFD for 16 weeks, and HQD (400 and 800 mg/kg) or polyene lecithin choline (PLC, 8 mg/kg) was given orally from week 8-16. Pharmacodynamic indicators including body weight, liver weight, liver index, as well as biochemical and histological parameters were assessed. As to mechanism exploration, the expressions of TLR4/NF-κB/NLRP3 pathway and molecular docking between major phytochemicals of HQD and key targets of TLR4/NF-κB/NLRP3 pathway were investigated.

RESULTS

Seven main monomeric constituents of HQD were revealed by HPLC analysis. Of note, HQD could effectively attenuate the body weight, liver weight, and liver index, rescue disorders in serum transaminases and lipid profile, correct hepatic histological abnormalities, and reduce phagocytes infiltration into the liver and pro-inflammatory cytokines release in NAFLD rats. Mechanism investigation discovered that HQD harbored inhibitory effects on TLR4/NF-κB/NLRP3 pathway-regulated liver inflammation. Further exploration found that seven phytochemicals in HQD exhibited better binding modes with TLR4/NF-κB/NLRP3 pathway, in which baicalein, baicalin and liquiritin presented the highest affinity and docking score for protein TLR4, NF-κB, and NLRP3, respectively.

CONCLUSIONS

These findings confirmed that HQD ameliorated hepatic inflammation in NAFLD rats by blocking the TLR4/NF-κB/NLRP3 pathway, with multi-components and multi-targets action pattern.

SRF/MRTF-A and liver cirrhosis: Pathologic associations

Liver cirrhosis results from prolonged and extensive liver fibrosis in which fibrotic tissues replace functional hepatic cells. Chronic liver disease due to various viral, chemical, or metabolic factors initiates hepatic fibrogenesis. Cirrhosis is associated with multiple clinical complications and a poor patient prognosis; therefore, developing novel antifibrotic therapies to prevent cirrhosis is of high priority. Mounting evidence points to the key role of serum response factor (SRF) and myocardin-related transcription factor (MRTF)-A in the pathogenesis of liver fibrosis. SRF is a transcription factor and MRTF-A is a co-activator of SRF and normally resides in the cytoplasm. Upon the induction of fibrotic pathways, MRTF-A translocates into the nucleus and forms the active SRF/MRTF-A complex, leading to the expression of a multitude of fibrotic proteins and components of extracellular matrix. Silencing or inhibiting MRTF-A impedes hepatic stellate cell transdifferentiation into myofibroblasts and slows down the deposition of extracellular matrix in the liver, making it a potential therapeutic target. Here, we review the recent findings regarding the role of the SRF/MRTF-A complex in liver fibrosis and its therapeutic potential for the management of cirrhosis.

Effect of Curcumin on Attenuation of Liver Cirrhosis via Genes/Proteins and Pathways: A System Pharmacology Study

Background: Liver cirrhosis is a life-threatening seqsuel of many chronic liver disorders of varying etiologies. In this study, we investigated protein targets of curcumin in liver cirrhosis based on a bioinformatics approach. Methods: Gene/protein associations with curcumin and liver cirrhosis were probed in drug−gene and gene−diseases databases including STITCH/DGIdb/DisGeNET/OMIM/DISEASES/CTD/Pharos and SwissTargetPrediction. Critical clustering groups (MCODE), hub candidates and critical hub genes in liver cirrhosis were identified, and connections between curcumin and liver cirrhosis-related genes were analyzed via Venn diagram. Interaction of hub genes with curcumin by molecular docking using PyRx-virtual screening tools was performed. Results: MCODE analysis indicated three MCODEs; the cluster (MCODE 1) comprised 79 nodes and 881 edges (score: 22.59). Curcumin database interactions recognized 318 protein targets. Liver cirrhosis genes and curcumin protein targets analysis demonstrated 96 shared proteins, suggesting that curcumin may influence 20 candidate and 13 hub genes, covering 81% of liver cirrhosis critical genes and proteins. Thirteen shared proteins affected oxidative stress regulation, RNA, telomerase activity, cell proliferation, and cell death. Molecular docking analysis showed the affinity of curcumin binding hub genes (Binding affinity: ΔG < −4.9 kcal/mol). Conclusions: Curcumin impacted on several critical liver cirrhosis genes mainly involved in extracellular matrix communication, focal adhesion, and the response to oxidative stress.

Hypermethylation of Mig-6 gene promoter region inactivates its function, leading to EGFR/ERK signaling hyperphosphorylation, and is involved in arsenite-induced hepatic stellate cells activation and extracellular matrix deposition

Arsenic is a widespread naturally contaminant. Previous studies have highlighted the issue of liver fibrosis induced by arsenic exposure, while the exact mechanisms are not yet fully understood. Recent studies suggest that Mig-6/EGFR/ERK signaling appear to play important roles in fibrosis caused by various factors. In this study, we focused on the epigenetic modification combined with the signaling dysregulation to validate the role of Mig-6 in regulating EGFR/ERK signaling in arsenite-induced human hepatic stellate cells (HSCs) activation. Our results revealed that arsenite exposure induced HSCs activation and extracellular matrix (ECM) deposition. The EGFR/ERK signaling was significantly hyperphosphorylated in arsenite-exposed HSCs, and Mig-6 inactivation was involved in arsenite induced hyperphosphorylation of EGFR and activation of HSCs. Additionally, we further illustrated that hypermethylation of Mig-6 gene promoter region was responsible for the downregulation of Mig-6 induced by arsenite exposure. Moreover, 5-Aza-dC (a DNA methyltransferase inhibitor) can efficiently rescue hypermethylation of Mig-6 gene, decrease the hyperphosphorylation of EGFR/ERK signaling, then reverse arsenite induced HSCs activation. Taken together, the present study strongly suggests that inactivating of Mig-6 function by hypermethylation of its promoter region leading to hyperphosphorylation of EGFR/ERK signaling, and is involved in arsenite-induced HSCs activation and ECM deposition.

Differential proteomic analysis of mouse cerebrums with high-fat diet (HFD)-induced hyperlipidemia

Hyperlipidemia is a chronic disease characterized by elevated blood cholesterol and triglycerides and there is accumulated evidence that the disease might affect brain functions. Here we report on a proteomic analysis of the brain proteins in hyperlipidemic mice. Hyperlipidemia was successfully induced in mice by a 20 week high-fat diet (HFD) feeding (model group). A control group with a normal diet and a treatment group with HFD-fed mice treated with a lipid-lowering drug simvastatin (SIM) were established accordingly. The proteins were extracted from the left and right cerebrum hemispheres of the mice in the three groups and subjected to shotgun proteomic analysis. A total of 4,422 proteins were detected in at least half of the samples, among which 324 proteins showed significant difference (fold change >1.5 or <0.67, p < 0.05) in at least one of the four types of comparisons (left cerebrum hemispheres of the model group versus the control group, right cerebrums of model versus control, left cerebrums of SIM versus model, right cerebrums of SIM versus model). Biological process analysis revealed many of these proteins were enriched in the processes correlated with lipid metabolism, neurological disorders, synaptic events and nervous system development. For the first time, it has been reported that some of the proteins have been altered in the brain under the conditions of HFD feeding, obesity or hyperlipidemia. Further, 22 brain processes-related proteins showed different expression in the two cerebrum hemispheres, suggesting changes of the brain proteins caused by hyperlipidemia might also be asymmetric. We hope this work will provide useful information to understand the effects of HFD and hyperlipidemia on brain proteins.

Protective Effects of Tiaoganquzhi Decoction in Treating inflammatory Injury of Nonalcoholic Fatty liver Disease by Promoting CGI-58 and Inhibiting Expression of NLRP3 Inflammasome

Tiaoganquzhi Decoction (TGQZD) is a traditional Chinese herbal formulation demonstrated to be a clinically effective treatment for nonalcoholic fatty liver disease (NAFLD), although details concerning its clinical mechanism are poor. This study aimed to explore the mechanism of TGQZD on improvement of inflammatory damage and dyslipidemia caused by NAFLD through the CGI-58/ROS/NLRP3 inflammasome pathway. In our research, the in vivo protective effects of TGQZD on HFD-induced liver injury in rats and in vitro using lipopolysaccharide (LPS)+palmitate (PA)-stimulated HepG-2 cells model. Histological changes were evaluated by hematoxylin-eosin and Oil Red O staining. Inflammatory cytokines and protein expression were analyzed by ELISA, Real time PCR and western blotting. Liver function, blood lipids, free fatty acids (FFA), and reactive oxygen species (ROS) were determined by biochemical detection. Our results indicated that TGQZD exhibited anti-inflammatory activity, reduced the severity of NAFLD and ameliorated the pathological changes. Further, TGQZD improved liver function and lipid metabolism in NAFLD rats. TGQZD lowered serum aspartate aminotransferase, alanine aminotransferase, triglyceride, and total cholesterol levels. TGQZD suppressed the formulation of FFA and ROS. It also reduced the expression and release of the inflammatory cytokine interleukin-1β by promoting CGI-58 expression and inhibiting the expression of FFA, TNF-α, and the NLRP3 inflammasome induced by ROS. TGQZD exhibited anti-inflammatory effects via the CGI-58, ROS and NLRP3 inflammasome pathway in vivo and in vitro, respectively. Our findings demonstrated that TGQZD is a useful and effective therapeutic agent for treating NAFLD via promotion of CGI-58 to inhibit the expression of ROS-induced NLRP3 inflammasome.

New advances of DNA/RNA methylation modification in liver fibrosis

Liver fibrosis is a complex pathological process caused by multiple pathogenic factors，such as ethanol, viruses, toxins, drugs or cholestasis, and it can eventually develop into liver cirrhosis without effective treatment. Activation of hepatic stellate cells (HSCs) is a pivotal cellular event in the pathogenesis of liver fibrosis. However, the pathogenesis of liver fibrosis has not been fully elucidated. DNA/RNA methylation can regulate gene expression without alteration in its sequence, and numerous studies have shown the involvement of DNA methylation in the activation of HSCs and then promote the progression of liver fibrosis. In addition, RNA methylation has recently been reported to play a regulatory role in this process. In this review, we focus on the aberrant DNA/RNA methylation of selected genes and explore their functional mechanism in regulating HSCs activation and liver fibrogenesis. All of these findings will enhance our understanding of DNA/RNA methylation and their roles in liver fibrosis and provide the basis to identify effective therapeutic targets.

SIMPLE Is an Endosomal Regulator That Protects Against NAFLD by Targeting the Lysosomal Degradation of EGFR

BACKGROUND AND AIMS

NAFLD has become a tremendous burden for public health; however, there is no drug for NAFLD therapy at present. Impaired endo-lysosome-mediated protein degradation is observed in a variety of metabolic disorders, such as atherosclerosis, type 2 diabetes mellitus, and NAFLD. Small integral membrane protein of lysosome/late endosome (SIMPLE) is a regulator of endosome-to-lysosome trafficking and cell signaling, but the role that SIMPLE plays in NAFLD progression remains unknown. Here we investigated SIMPLE function in NAFLD development and sophisticated mechanism therein.

APPROACH AND RESULTS

This study found that in vitro knockdown of SIMPLE significantly aggravated lipid accumulation and inflammation in hepatocytes treated with metabolic stimulation. Consistently, in vivo experiments showed that liver-specific Simple-knockout (Simple-HKO) mice exhibited more severe high-fat diet (HFD)-induced, high-fat-high-cholesterol diet (HFHC)-induced, and methionine-choline-deficient diet (MCD)-induced steatosis, glucose intolerance, inflammation, and fibrosis than those fed with normal chow (NC) diet. Meanwhile, RNA-sequencing demonstrated the up-regulated signaling pathways and signature genes involved in lipid metabolism, inflammation, and fibrosis in Simple-HKO mice compared with control mice under metabolic stress. Mechanically, we found SIMPLE directly interact with epidermal growth factor receptor (EGFR). SIMPLE deficiency results in dysregulated degradation of EGFR, subsequently hyperactivated EGFR phosphorylation, thus exaggerating NAFLD development. Moreover, we demonstrated that using EGFR inhibitor or silencing EGFR expression could ameliorate lipid accumulation induced by the knockdown of SIMPLE.

CONCLUSIONS

SIMPLE ameliorated NASH by prompting EGFR degradation and can be a potential therapeutic candidate for NASH.

Exploring the Gamut of Receptor Tyrosine Kinases for Their Promise in the Management of Non-Alcoholic Fatty Liver Disease

Recently, non-alcoholic fatty liver disease (NAFLD) has emerged as a predominant health concern affecting approximately a quarter of the world's population. NAFLD is a spectrum of liver ailments arising from nascent lipid accumulation and leading to inflammation, fibrosis or even carcinogenesis. Despite its prevalence and severity, no targeted pharmacological intervention is approved to date. Thus, it is imperative to identify suitable drug targets critical to the development and progression of NAFLD. In this quest, a ray of hope is nestled within a group of proteins, receptor tyrosine kinases (RTKs), as targets to contain or even reverse NAFLD. RTKs control numerous vital biological processes and their selective expression and activity in specific diseases have rendered them useful as drug targets. In this review, we discuss the recent advancements in characterizing the role of RTKs in NAFLD progression and qualify their suitability as pharmacological targets. Available data suggests inhibition of Epidermal Growth Factor Receptor, AXL, Fibroblast Growth Factor Receptor 4 and Vascular Endothelial Growth Factor Receptor, and activation of cellular mesenchymal-epithelial transition factor and Fibroblast Growth Factor Receptor 1 could pave the way for novel NAFLD therapeutics. Thus, it is important to characterize these RTKs for target validation and proof-of-concept through clinical trials.

Epidermal growth factor receptor inhibitors as potential anticancer agents: An update of recent progress

Epidermal growth factor receptor (EGFR) is a vital intermediate in cell signaling pathway including cell proliferation, angiogenesis, apoptosis, and metastatic spread and also having four divergent members with similar structural features, such as EGFR (HER1/ErbB1), ErbB2 (HER2/neu), ErbB3 (HER3), and ErbB4 (HER4). Despite this, clinically exploited inhibitors of EGFR (including erlotinib, lapatinib, gefitinib, selumetinib, etc.) are not specific thus provoking unenviable adverse effects. Some of the paramount obstacles to generate and develop new lead molecules of EGFR inhibitors are drug resistance, mutation, and also selectivity which inspire medicinal chemists to generate novel chemotypes. The discovery of therapeutic agents that inhibit the precise stage in tumorous cells such as EGFR is one of the chief successful targets in many cancer therapies, including lung and breast cancers. This review aims to compile the various recent progressions (2016-2021) in the discovery and development of diverse epidermal growth factor receptor (EGFR) inhibitors belonging to distinct structural classes like pyrazoline, pyrazole, imidazole, pyrimidine, coumarin, benzothiazole, etc. We have summarized preclinical and clinical data, structure-activity relationships (SAR) containing mechanistic and in silico studies to provide proposals for the design and invention of new EGFR inhibitors with therapeutic significance. The detailed progress of the work in the field will provide inexorable scope for the development of novel drug candidates with greater selectivity and efficacy.

Integrated MicroRNA Expression Profile Reveals Dysregulated miR-20a-5p and miR-200a-3p in Liver Fibrosis

MicroRNAs (miRNAs) have been demonstrated to involve in liver fibrogenesis. However, the miRNA-gene regulation in liver fibrosis is still unclear. Herein, the miRNA expression profile GSE40744 was obtained to analyze the dysregulated miRNAs between liver fibrosis and normal samples. Then, we predicted the target genes of screened miRNAs by miRTarBase, followed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Then, the protein-protein interaction (PPI) network was constructed to identify the functional miRNA-gene regulatory modules. Furthermore, we verified the hub gene expression using the gene expression profile GSE14323. Finally, 89 DEMs were identified in fibrotic liver samples compared to normal liver samples. The top 3 upregulated DEMs (miR-200b-3p, miR-200a-3p, and miR-182-5p) and downregulated DEMs (miR-20a-5p, miR-194-3p, and miR-148a-3p) were further studied. 516 and 1416 target genes were predicted, respectively. KEGG analysis demonstrated that the predicted genes were enriched in the p53 signaling pathway and hepatitis B, etc. Through constructing a PPI network, the genes with the highest connectivity were identified as hub genes. Of note, most of the hub genes were potentially targeted by miR-20a-5p and miR-200a-3p. Based on the data from GSE14323, the expression of EGFR, STAT3, CTNNB1, and TP53 targeted by miR-200a-3p was significantly downregulated in fibrotic liver samples. Oppositely, the expression of PTEN, MYC, MAPK1, UBC, and CCND1 potentially targeted by miR-20a-5p was significantly upregulated. In conclusion, it is demonstrated that miR-20a-5p and miR-200a-3p were identified as the novel liver fibrosis-associated miRNAs, which may play critical roles in liver fibrogenesis.

Emerging synthetic drugs for the treatment of liver cirrhosis

Introduction: The number of deaths and prevalent cases of cirrhosis are increasing worldwide, but there are no licensed antifibrotic or pro-regenerative medicines and liver transplantation is a limited resource. Cirrhosis is characterized by extreme liver fibrosis, organ dysfunction, and complications related to portal hypertension. Advances in our understanding of liver fibrosis progression and regression following successful etiological therapy betray vulnerabilities in common and disease-specific mechanisms that could be targeted pharmacologically.Area covered: This review summarizes the cellular and molecular pathogenesis of cirrhosis as a preface to discussion of the current drug development landscape. The dominant indication for global pharma R&D pipelines is cirrhosis related to nonalcoholic steatohepatitis (NASH). We searched Clinicaltrials.gov, GlobalData, Pharmaprojects and PubMed for pertinent information on emerging synthetic drugs for cirrhosis, with a focus on compounds listed in phase 2 and phase 3 trials.Expert opinion: Although cirrhosis can regress following successful etiological treatment, there are no specific antifibrotic or pro-regenerative drugs approved for this condition. Obstacles to drug development in cirrhosis include intrinsic biological factors, a heterogeneous patient population, and lack of acceptable surrogate endpoints. Nevertheless, several synthetic drugs are being evaluated in clinical trials and the NASH field is rapidly embracing a drug combination approach.

Identifying potential biomarkers of nonalcoholic fatty liver disease via genome-wide analysis of copy number variation

BACKGROUND

The prevalence of Non-alcoholic fatty liver disease (NAFLD) is increasing and emerging as a global health burden. In addition to environmental factors, numerous studies have shown that genetic factors play an important role in the development of NAFLD. Copy number variation (CNV) as a genetic variation plays an important role in the evaluation of disease susceptibility and genetic differences. The aim of the present study was to assess the contribution of CNV to the evaluation of NAFLD in a Chinese population.

METHODS

Genome-wide analysis of CNV was performed using high-density comparative genomic hybridisation microarrays (ACGH). To validate the CNV regions, TaqMan real-time quantitative PCR (qPCR) was utilized.

RESULTS

A total of 441 CNVs were identified, including 381 autosomal CNVs and 60 sex chromosome CNVs. By merging overlapping CNVs, a genomic CNV map of NAFLD patients was constructed. A total of 338 autosomal CNVRs were identified, including 275 CNVRs with consistent trends (197 losses and 78 gains) and 63 CNVRs with inconsistent trends. The length of the 338 CNVRs ranged from 5.7 kb to 2.23 Mb, with an average size of 117.44 kb. These CNVRs spanned 39.70 Mb of the genome and accounted for ~ 1.32% of the genome sequence. Through Gene Ontology and genetic pathway analysis, we found evidence that CNVs involving nine genes may be associated with the pathogenesis of NAFLD progression. One of the genes (NLRP4 gene) was selected and verified by quantitative PCR (qPCR) method with large sample size. We found the copy number deletion of NLRP4 was related to the risk of NAFLD.

CONCLUSIONS

This study indicate the copy number variation is associated with NAFLD. The copy number deletion of NLRP4 was related to the risk of NAFLD. These results could prove valuable for predicting patients at risk of developing NAFLD.

Epiregulin (EREG) and Myocardin Related Transcription Factor A (MRTF-A) Form a Feedforward Loop to Drive Hepatic Stellate Cell Activation

Trans-differentiation of quiescent hepatic stellate cells (HSC) into myofibroblast cells is considered the linchpin of liver fibrosis. A myriad of signaling pathways contribute to HSC activation and consequently liver fibrosis. Epidermal growth factor (EGF) family of cytokines signal through the cognate receptor EGFR to promote HSC activation. In the present study we investigated the transcription regulation of epiregulin (EREG), an EGFR ligand, during HSC activation. We report that EREG expression was significantly up-regulated in activated HSCs compared to quiescent HSCs isolated from mice. In addition, there was an elevation of EREG expression in HSCs undergoing activation in vitro. Of interest, deficiency of myocardin-related transcription factor A (MRTF-A), a well-documented regulator of HSC trans-differentiation, attenuated up-regulation of EREG expression both in vivo and in vitro. Further analysis revealed that MRTF-A interacted with serum response factor (SRF) to bind directly to the EREG promoter and activate EREG transcription. EREG treatment promoted HSC activation in vitro, which was blocked by MRTF-A depletion or inhibition. Mechanistically, EREG stimulated nuclear trans-location of MRTF-A in HSCs. Together, our data portray an EREG-MRTF-A feedforward loop that contributes to HSC activation and suggest that targeting the EREG-MRTF-A axis may yield therapeutic solutions against liver fibrosis.

The Role of RECK in Hepatobiliary Neoplasia Reveals Its Therapeutic Potential in NASH

Non-alcoholic fatty liver disease (NAFLD) is a multimorbidity disorder ranging from excess accumulation of fat in the liver (steatosis) to steatohepatitis (NASH) and end-stage cirrhosis, and the development of hepatocellular carcinoma (HCC) in a subset of patients. The defining features of NASH are inflammation and progressive fibrosis. Currently, no pharmaceutical therapies are available for NAFLD, NASH and HCC; therefore, developing novel treatment strategies is desperately needed. Reversion Inducing Cysteine Rich Protein with Kazal motifs (RECK) is a well-known modifier of the extracellular matrix in hepatic remodeling and transition to HCC. More recently, its role in regulating inflammatory and fibrogenic processes has emerged. Here, we summarize the most relevant findings that extend our current understanding of RECK as a regulator of inflammation and fibrosis, and its induction as a potential strategy to blunt the development and progression of NASH and HCC.

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.

Role of epidermal growth factor receptor in liver injury and lipid metabolism: Emerging new roles for an old receptor

Epidermal growth factor receptor (EGFR) is conventionally known to play a crucial role in hepatocyte proliferation, liver regeneration and is also associated with hepatocellular carcinogenesis. In addition to these proliferative roles, EGFR has also implicated in apoptotic cell death signaling in various hepatic cells, mitochondrial dysfunction and acute liver necrosis in a clinically relevant murine model of acetaminophen overdose, warranting further comprehensive exploration of this paradoxical role of EGFR in hepatotoxicity. Apart from ligand dependent activation, EGFR can also be activated in ligand-independent manner, which is mainly associated to liver injury. Recent evidence has also emerged demonstrating important role of EGFR in lipid and fatty acid metabolism in quiescent and regenerating liver. Based on these findings, EGFR has also been shown to play an important role in steatosis in clinically relevant murine NAFLD models via regulating master transcription factors governing fatty acid synthesis and lipolysis. Moreover, several lines of evidences indicate that EGFR is also involved in hepatocellular injury, oxidative stress, inflammation, direct stellate cell activation and fibrosis in chronic liver injury models, including repeated CCl4 exposure, high-fat diet and fast-food diet models. In addition to briefly summarizing role of EGFR in liver regeneration, this review comprehensively discusses all these non-conventional emerging roles of EGFR. Considering evidences of multi-facet role of EGFR at various levels in these pathophysiological process, EGFR can be a promising therapeutic target for various liver diseases, including acute liver failure and NAFLD, requiring further exploration. These roles of EGFR are relevant for alcoholic liver diseases (ALD) as well, thus providing a valid rationale for future investigations exploring a role of EGFR in ALD.

EGF neutralization antibodies attenuate liver fibrosis by inhibiting myofibroblast proliferation in bile duct ligation mice

The expression of epidermal growth factor (EGF) is increased during liver fibrogenesis, and EGF receptor (EGFR) antagonist could attenuate liver fibrosis. Since EGFR is highly expressed by hepatocytes and cholangiocytes in cirrhotic liver, whether hepatic stellate cells express EGFR in response to EGF still needs exploration. Although EGFR antagonist could attenuate liver fibrosis, many ligands with EGF-like domains, besides EGF, can function through EGFR. Whether specifically blocking EGF could attenuate bile duct ligation (BDL)-induced liver fibrosis has not been revealed. BDL induced biliary infarcts and matrix deposition in mouse liver, and EGFR was expressed and phosphorylated by α-smooth muscle actin (αSMA)-positive myofibroblasts. LX-2 cells expressed EGFR, and these receptors were phosphorylated in the in vitro culture system. Growth curve and cell cycle analysis revealed that EGF could enhance cell proliferation of LX-2 cells. In addition, administration of EGF antibodies markedly reduced the EGF level in serum and the deposition of extracellular matrix in the liver of BDL mice when compared to IgG administration. Administration of EGF antibodies also reduced the phosphorylation of EGFR and the percentage of Ki-67-positive or PCNA-positive liver myofibroblasts of BDL mice when compared to IgG administration. Therefore, activated hepatic stellate cells express EGFR, thus being responsive to EGF signal, and administration of EGF antibodies could attenuate liver fibrosis by restricting the proliferation of myofibroblasts.

Silibinin Augments the Antifibrotic Effect of Valsartan Through Inactivation of TGF-β1 Signaling in Kidney

Background

Chronic kidney disease (CKD) has become a major public health issue. Meanwhile, renal fibrosis caused by diabetic nephropathy can lead to CKD, regardless of the initial injury. It has been previously reported that silibinin or valsartan could relieve the severity of renal fibrosis. However, the effect of silibinin in combination with valsartan on renal fibrosis remains unclear.

Material and Methods

Proximal tubular cells (HK-2) were treated with TGF-β1 (5 ng/mL) to mimic in vitro model of fibrosis. The proliferation of HK-2 cells was tested by CCK-8. Epithelial-mesenchymal transition (EMT) and inflammation-related gene and protein expressions in HK-2 cells were measured by qRT-PCR and Western-blot, respectively. ELISA was used to test the level of TNF-αNF-A. Additionally, HFD-induced renal fibrosis mice model was established to investigate the effect of silibinin in combination with valsartan on renal fibrosis in vivo.

Results

Silibinin significantly increased the anti-fibrosis effect of valsartan in TGF-β1-treated HK-2 cells via inhibition of TGF-β1 signaling pathway. Furthermore, silibinin significantly enhanced the anti-fibrosis effect of valsartan on HFD-induced renal fibrosis in vivo through inactivation of TGF-β1 signaling pathway.

Conclusion

These data indicated that silibinin markedly increased anti-fibrosis effect of valsartan in vitro and in vivo. Thus, silibinin in combination with valsartan may act as a potential novel strategy to treat renal fibrosis caused by diabetic nephropathy.

Water-soluble pristine C60 fullerene attenuates acetaminophen-induced liver injury

Introduction: Oxidative stress has been suggested as the main trigger and pathological mechanism of toxic liver injury. Effects of powerful free radical scavenger С₆₀ fullerene on rat liver injury and liver cells (HepG2 line) were aimed to be discovered.

Methods: Acute liver injury (ALI) was simulated by single acetaminophen (APAP, 1000 mg/kg) administration, on a chronic CLI, by 4 weekly APAP administrations. Pristine C₆₀ fullerene aqueous colloid solution (C₆₀FAS; initial concentration 0.15 mg/mL) was administered per os or intraperitoneally at a dose of 0.5 mg/kg (ALI) or 0.25 mg/kg (CLI) daily for 2 or 28 days, respectively, after first APAP dose. Animals were sacrificed at 24th hour after the last dose. Biochemical markers of blood serum and liver autopsies were analyzed. EGFR expression in HepG2 cells after 48-hour incubation with C₆₀FAS was assessed.

Results: Increase of serum conjugated and unconjugated bilirubin (up to 1.4-3.7 times), ALT (by 31-37%), and AST (by 18%) in non-treated ALI and CLI rats were observed, suggesting the hepatitis (confirmed by histological analysis). Liver morphological state (ALI, CLI), ALT (ALI and CLI), bilirubin (CLI), α-amylase, and creatinine (ALI) were normalized with C₆₀FAS administration in both ways, which may indicate its protective impact on liver. However, unconjugated bilirubin sharply increased in ALI animals receiving C₆₀FAS (up to 12 times compared to control), suggesting the augmentation of bilirubin metabolism. Furthermore, C₆₀FAS inhibited EGFR expression in HepG2 cells in a dose-dependent manner.

Conclusion: C₆₀FAS could partially correct acute and chronic toxic liver injury, however, it could not normalize bilirubin metabolism after acute exposure.

Matrine attenuates endoplasmic reticulum stress and mitochondrion dysfunction in nonalcoholic fatty liver disease by regulating SERCA pathway

Background

Endoplasmic reticulum (ER) stress, which can promote lipid metabolism disorders and steatohepatitis, contributes significantly to the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Calcium (Ca²⁺) homeostasis is considered to play a key role in ER stress. Matrine (Mat) has been applied for the treatment of hepatitis B, but its effect on NAFLD is still unknown, and there is no unified view of Mat on the regulation of ER stress in the previous literature.

Methods

The pharmacological effects were studied in high-fat-diet or methionine–choline-deficient diet induced C57BL/6J mice models and in palmitic acid (PA) induced L02 human liver cell model. Calcium fluorescence experiments, computational virtual docking analysis and biochemical assays were used in identifying the locus of Mat.

Results

The results showed that Mat-treated mice were more resistant to steatosis in the liver than vehicle-treated mice and that Mat significantly reduced hepatic inflammation, lipid peroxides. The beneficial effect of Mat was associated with suppressing ER stress and restoring mitochondrial dysfunction. Additionally, Mat decreased the PA-induced lipid accumulation, ER stress and cytosolic calcium level ([Ca²⁺]_c) in hepatocyte cell lines in low and middle dose. However, the high dose Mat did not show satisfactory results in cell model. Calcium fluorescence experiments showed that Mat was able to regulate [Ca²⁺]_c. By computational virtual docking analysis and biochemical assays, Mat was shown to influence [Ca²⁺]_c via direct inhibition of SERCA.

Conclusions

The results showed that the bi-directional regulation of Mat to endoplasmic reticulum at different doses was based on the inhibition of SERCA. In addition, the results also provide a theoretical basis for Mat as a potential therapeutic strategy in NAFLD/NASH.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1685-2) contains supplementary material, which is available to authorized users.

Inhibition of Epidermal Growth Factor Receptor (EGFR) Reduces Lipopolysaccharide (LPS)-Induced Activation and Inflammatory Cytokines in Hepatic Stellate Cells In Vitro

BACKGROUND Epidermal growth factor receptor (EGFR) expression is associated with hepatic fibrogenesis. Activated hepatic stellate cells (HSCs) release inflammatory cytokines and extracellular matrix (ECM). The aim of this in vitro study was to investigate HSCs, activated by lipopolysaccharide (LPS), and the role of EGFR using the small molecule EGFR inhibitor, AG1478, and using knockdown of the EGFR gene using small interfering RNA (siRNA) cell transfection. MATERIAL AND METHODS HSCs, isolated from male Sprague-Dawley rats, were cultured and treated with and without LPS (100 ng/mL), with and without AG1478 (2.5 μM and 5.0 μM) Cell survival and proliferation were studied using an MTT assay. Western blot was used to measure levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IκBα, cytoplasm and nuclear NFκB and EGFR in the cell lysates before and after small interfering RNA (siRNA) transfection. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to measure the mRNA levels of transforming growth factor (TGF)-β, Col-1, and α-smooth muscle actin (SMA). The Toll-like receptor 4 (TLR4) antagonist TAK-242 and the selective c-Src inhibitor, PP2 in LPS induced-EGFR phosphorylation was evaluated using Western blot. RESULTS Inhibition of EGFR decreased LPS-induced HSC proliferation and inflammatory cytokines. The TLR4 antagonist TAK-242, and the c-Src inhibitor, PP2 reduced EGFR activation of HSCs, indicating a possible role for the TLR4/c-Src signaling cascade in LPS-induced HSC activation. CONCLUSIONS Activation of HSCs by LPS in vitro, including the expression of inflammatory cytokines and mediators of fibrogenesis, were shown to be dependent on the expression of EGFR.