Pathogenesis of liver fibrosis

Salvianolic acid B ameliorates hepatic fibrosis via inhibiting p300/CBP

Salvianolic acid B (Sal B), an active ingredient extracted from Salvia miltiorrhiza Bunge, has shown hepatic anti-fibrotic activity. Hepatic stellate cells (HSCs) activation is considered the determining event in liver fibrogenesis. E1A binding protein p300 (p300)/CREB binding protein (CBP) is an attractive target for inhibiting HSCs activation. But whether Sal B inhibits hepatic fibrosis through suppressing p300/CBP is unknown. We used DEN/CCl4/C2H5OH to establish a mouse model of hepatic fibrosis and detect the effects of Sal B on liver function, pathological alterations, and p300/CBP expression. TGF-β1 was used to induce LX-2 cells for in vitro experimental validation. Additionally, the effects of Sal B on LX-2 activation were explored using the p300/CBP activator CTB, and molecular docking was used to predict the interaction between Sal B and p300. The in vivo results demonstrated that Sal B improved liver function, reversed pathological changes, reduced collagen synthesis, and downregulated the protein levels of p300 and CBP in DEN/CCl4/C2H5OH-induced hepatic fibrosis mice. The in vitro results showed that Sal B inhibited LX-2 cells activation and decreased both the mRNA and protein levels of p300 and CBP. Furthermore, the p300/CBP activator CTB reversed the inhibitory effect of Sal B on LX-2 cells activation. Molecular docking showed that Sal B bound well to p300 with a high degree of match and a binding energy of -14.859 kcal/mol. Our study revealed that Sal B ameliorates hepatic fibrosis, which likely via inhibition of p300/CBP. However, the specific binding site deserves further exploration.

Hepatic antifibrotic effects of bezafibrate in vitro and in vivo models of liver fibrosis

Bezafibrate (BZF) is a drug that reduces cholesterol and triglyceride levels in the blood. Research indicates that BZF, through activation of PPAR receptors, regulates the expression of genes involved in lipid homeostasis, inflammation, cell differentiation, and proliferation. This study investigated the in vitro and in vivo effects of BZF on activated hepatic stellate cells (HSCs) and on carbon tetrachloride-induced liver fibrosis in mice. After 72 h of treatment in vitro, BZF decreased cell proliferation, reversed the phenotype, decreased cell contraction, and induced autophagy. In addition, BZF promoted a protective effect on tetrachloride-induced liver fibrosis in mice, through antifibrotic actions. These findings suggest that BZF may have a potential antifibrotic effect, which could emerge as a possible new therapy for the treatment of liver fibrosis.

LOX-1 rewires glutamine ammonia metabolism to drive liver fibrosis

OBJECTIVE

Liver fibrosis is a crucial condition for evaluating the prognosis of chronic liver disease. Lectin-1ike oxidized low density lipoprotein receptor-1 (LOX-1) has been shown potential research value and therapeutic targeting possibilities in different fibrotic diseases. However, the role of LOX-1 and the underlying mechanisms in liver fibrosis progression remain unclear.

METHODS

LOX-1 expression was detected in liver tissues from patients and rodents with liver fibrosis. LOX-1 knockout rats were subjected to CCl4 or methionine and choline-deficient diet (MCD) to induce liver fibrosis. Transcriptomic and metabolomics analysis were used to investigate the involvement and mechanism of LOX-1 on liver fibrosis.

RESULTS

We found that LOX-1 exacerbated liver fibrosis by promoting hepatic stellate cells (HSCs) activation. LOX-1 deletion reversed the development of liver fibrosis. We further verified that LOX-1 drove liver fibrosis by reprogramming glutamine metabolism through mediating isoform switching of glutaminase (GLS). Mechanistically, we revealed the crucial role of the LOX-1/OCT1/GLS1 axis in the pathogenesis of liver fibrosis. Moreover, LOX-1 rewired ammonia metabolism by regulating glutamine metabolism-urea cycle to drive the progression of liver fibrosis.

CONCLUSIONS

Our findings uncover the pivotal role of LOX-1 in the progression of liver fibrosis, enrich the pathological significance of LOX-1 regulation of hepatic ammonia metabolism, and provide an insight into promising targets for the therapeutic strategy of liver fibrosis, demonstrating the potential clinical value of targeting LOX-1 in antifibrotic therapy.

New insights into therapeutic strategies for targeting hepatic macrophages to alleviate liver fibrosis

Liver fibrosis is a wound-healing response induced by persistent liver damage, resulting from complex multicellular interactions and multifactorial networks. Without intervention, it can progress to cirrhosis and even liver cancer. Current understanding suggests that liver fibrosis is reversible, making it crucial to explore effective therapeutic strategies for its alleviation. Chronic inflammation serves as the primary driver of liver fibrosis, with hepatic macrophages playing a dual role depending on their polarization state. This review summarizes various prevention and therapeutic strategies targeting hepatic macrophages in the context of liver fibrosis. These strategies include inhibition of macrophage recruitment, modulation of macrophage activation and polarization, regulation of macrophage metabolism, and induction of phagocytosis and autophagy in hepatic macrophages. Additionally, we discuss the communication between hepatic macrophages, hepatocytes, and hepatic stellate cells (HSCs), as well as the current clinical application of anti-fibrotic drugs targeting macrophages. The goal is to identify effective therapeutic targets at each stage of macrophage participation in liver fibrosis development, with the aim of using hepatic macrophages as a target for liver fibrosis treatment.

Immune-endothelial cell crosstalk in hepatic endothelial injury of liver fibrotic mice

INTRODUCTION

Liver fibrosis is a common pathological process in chronic liver disease, reflecting the advanced stage of the disease. Liver endothelial cells (ECs), especially liver sinusoidal endothelial cells (LSECs), are recognized as critical modulators of liver homeostasis and play essential roles in the recruitment and function of liver immune cells. In this study, we aimed to explore the mechanism of hepatic EC injury and the potential regulatory pathways of intercellular communication in liver fibrosis.

METHODS

In this study, C57BL/6 male mice were treated with CCl4 for 6 weeks to establish a liver fibrosis model. Masson staining and immunohistochemistry were performed to assess the extent of liver fibrosis. Hepatic endothelial injury was detected by using scanning electron microscopy (SEM) and PCR technology. Single-cell RNA sequencing (scRNA-seq) was performed to analyze phenotypic changes in nonparenchymal cells and dissect intercellular crosstalk.

RESULTS

A total of 24,534 cells were clustered into 10 main cell subsets. The LSEC fenestrae and surface receptor expression were reduced, and the expression of Cd34 was upregulated. Liver ECs exhibited dense cellular crosstalk with immune cells (macrophages, T and B cells). The analysis of intercellular signaling pathways revealed that immune cells targeted liver ECs through the Ptprc-Mrc1 and Sell-Podxl signaling pathways to maintain cellular interactions during liver fibrosis.

CONCLUSION

We revealed apparent damage and capillarization of liver ECs and demonstrated the cell-cell communications among liver immune cells and ECs during the development of liver fibrosis. The Ptprc-Mrc1 and Sell-Podxl signaling pathways exerted prominent roles in liver immune cell-EC interactions.

Aldose Reductase -Mediated HUR Ubiquitination Enhances Exosome Release and Hepatic Fibrosis via ROS/PI3K/AKT Pathway

INTRODUCTION

Liver fibrosis is caused by the activation of hepatic stellate cells due to various reasons. Our previous research has shown that aldose reductase (AR) played an important role in liver ischemia-reperfusion injury and liver regeneration.

OBJECTIVES

Here, we aimed to investigate the role and mechanism of AR in the progression of liver fibrosis induced by various factors.

METHODS

AR expression was detected in liver tissue of fibrosis patients and mouse models. The role and mechanism of AR in fibrosis progression were investigated in AR knockout mice and cell lines.

RESULTS

AR expression was increased in liver from patients with fibrosis and mouse models. The knockout of AR protected against CCL4 or HFD induced liver injury and development of fibrosis. Furthermore, AR promoted ubiquitization degradation of HUR through competitive binding with OTUB1, thereby exacerbating the accumulation of ROS, and ultimately activating PI3K/AKT pathway. The impaired autophagolysosome resulted in the massive release of exosomes, which activated stellate cells by regulating PTP4a1/ SMAD3 pathway. The hepatocyte specific recovery of AR in AR knockout mice aggravated ROS damage and fibrosis, while recovery of HUR in wild-type mice reduced ROS damage and fibrosis.

CONCLUSIONS

In conclusion, these findings suggest that AR might be a promising therapeutic target for treating liver fibrosis.

Cellular crosstalk in fibrosis: insights into macrophage and fibroblast dynamics

Pathological fibrosis, the excessive deposition of extracellular matrix and tissue stiffening that causes progressive organ dysfunction, underlies diverse chronic diseases. The fibrotic microenvironment is driven by the dynamic microenvironmental interaction between various cell types; macrophages and fibroblasts play central roles in fibrotic disease initiation, maintenance, and progression. Macrophage functional plasticity to microenvironmental stimuli modulates fibroblast functionality by releasing pro-inflammatory cytokines, growth factors, and matrix remodeling enzymes that promote fibroblast proliferation, activation, and differentiation into myofibroblasts. Activated fibroblasts and myofibroblasts serve as the fibrotic effector cells, secreting extracellular matrix components and initiating microenvironmental contracture. Fibroblasts also modulate macrophage function through the release of their own pro-inflammatory cytokines and growth factors, creating bidirectional crosstalk that reinforces the chronic fibrotic cycle. The intricate interplay between macrophages and fibroblasts, including their secretomes and signaling interactions, leads to tissue damage and pathological loss of tissue function. In this review, we examine macrophage-fibroblast reciprocal dynamic interactions in pathological fibrotic conditions. We discuss the specific lineages and functionality of macrophages and fibroblasts implicated in fibrotic progression, with focus on their signal transduction pathways and secretory signalling that enables their pro-fibrotic behaviour. We then finish with a set of recommendations for future experimentation with the goal of developing a set of potential targets for anti-fibrotic therapeutic candidates. Understanding the cellular interactions between macrophages and fibroblasts provides valuable insights into potential therapeutic strategies to mitigate fibrotic disease progression.

Peptidoglycan isolated from the fruit of Lycium barbarum alleviates liver fibrosis in mice by regulating the TGF-β/Smad7 signaling and gut microbiota

The hepatoprotective effect of the fruit of Lycium barbarum has been documented in China over millennia. Lycium barbarum polysaccharides (LBPs) were the first macromolecules reported to mitigate liver fibrosis in carbon tetrachloride (CCl4)-treated mice. Herein, a neutral peptidoglycan, named as LBPW, was extracted from the fruit of Lycium barbarum. In this study, we investigated the hepatoprotective mechanisms of LBPW. CCl4-induced liver fibrosis mice were administered LBPW (50, 100, 200 mg ·kg-1 ·d-1, i.p.) or (100, 200, 300 mg· kg-1 ·d-1, i.g.) for 6 weeks. We showed that either i.p. or i.g. administration of LBPW dose-dependently attenuated liver damage and fibrosis in CCl4-treated mice. Pharmacokinetic analysis showed that cyanine 5.5 amine (Cy5.5)-labeled LBPW (Cy5.5-LBPW) could be detected in the liver through i.p. and i.g. administration with i.g.-administered Cy5.5-LBPW mainly accumulating in the intestine. In TGF-β1-stimulated LX-2 cells as well as in the liver of CCl4-treated mice, we demonstrated that LBPW significantly upregulated Smad7, a negative regulator of TGF-β/Smad signaling, to retard the activation of hepatic stellate cells (HSCs) and prevent liver fibrosis. On the other hand, LBPW significantly boosted the abundance of Akkermansia muciniphila (A. muciniphila) and fortified gut barrier function. We demonstrated that A. muciniphila might be responsible for the efficacy of LBPW since decreasing the abundance of this bacterium by antibiotics (Abs) blocked the effectiveness of LBPW. Overall, our results show that LBPW may exert the hepatoprotective effect via rebalancing TGF-β/Smad7 signaling and propagating gut commensal A. muciniphila, suggesting that LBPW could be leading components to be developed as new drug candidates or nutraceuticals against liver fibrosis.

Precision Strike Strategy for Liver Diseases Trilogy with Xiao-Chai-Hu Decoction: A Meta-Analysis with Machine Learning

BACKGROUND AND PURPOSE

The progression from hepatitis to liver fibrosis (LF) and ultimately to hepatic carcinoma (HCC) represents the advanced stages of various liver diseases. Currently, no universal treatment effectively addresses all three conditions. The Traditional Chinese Medicine formula Xiao-Chai-Hu decoction (XCHD) has shown promise in treating hepatitis, inhibiting LF, and serving as an adjunct therapy for HCC. This study evaluates the efficacy and optimal treatment durations of XCHD in managing these liver diseases using meta-analysis and machine learning techniques.

METHODS

Registered in the PROSPERO database (CRD42024534445), this meta-analysis systematically searched seven databases, including 54 studies with a total of 5,710 patients. Statistical analysis was performed using Stata 17.0. Five machine learning models-Random Forest (RF), XGBoost, Lasso, Multilayer Perceptron (MLP), and a stacking model combining these algorithms-were employed to analyze the data and predict the time-effect relationships. The optimal durations of XCHD treatment for the liver disease trilogy were subsequently projected.

RESULTS

XCHD significantly improved the primary outcome indicators for hepatitis, liver fibrosis, and HCC. Additionally, XCHD demonstrated a beneficial effect on liver dysfunction caused by these diseases. Machine learning predicted the optimal treatment durations of XCHD as 12 weeks for hepatitis, 20.31 weeks for liver fibrosis, and 12 weeks for HCC.

CONCLUSION

XCHD is effective in treating the liver disease trilogy, with optimal treatment durations of 12 weeks for hepatitis and HCC, and 20.31 weeks for liver fibrosis. These findings support the potential of XCHD in developing precise clinical strategies for managing liver diseases. This study innovatively integrates meta-analysis with machine learning to determine the optimal treatment durations, providing a novel approach for evidence-based precision medicine in Traditional Chinese Medicine.

Highly oxygenated lanostane triterpenoids from Ganoderma applanatum and their anti-liver fibrosis effects

Inspired by the intriguing structures and significant activities of Ganoderma triterpenoids (GTs), the EtOAc extract of Ganoderma applanatum was phytochemically investigated, leading to the isolation of 11 GTs, including 10 new one (1-10). Their structures including absolute configurations, were elucidated through IR, UV, HRESIMS, 1D NMR and 2D NMR data analyses. Notably, applanoids J (1) and K (2) represent the first example of GTs with an unprecedented B-seco-lanostane architecture featuring 1,4-cyclohexanedione motif. Meanwhile, compounds 1-7 and 9-11 were evaluated for their hepatoprotective activity using TGF-β1-induced liver fibrosis model, and some of them such as compounds 2, 4, 6, 7 and 10 significantly suppressed the abnormal upregulation of fibrosis-related genes FN, ACTA2 (encode α-SMA) and COL1A1. Mechanistic studies suggested that the anti-liver fibrosis effect of compound 7 may be mediated through inhibition of the TGF-β/Smad signaling pathway. This study not only illustrates the structural diversity of GTs but also highlights their potential as promising anti-liver fibrosis agents.

Transforming Myofibroblasts Into Lipid-Filled Cells to Treat Dupuytren Disease

PURPOSE

Transforming myofibroblasts (MFs) into adipocyte-like cells may be a viable option for treating Dupuytren disease. Human Dupuytren MFs (DMFs) and adipose-derived stem cells (ASCs) cocultured in the presence of platelet-rich plasma (PRP) reprogrammed into lipid-laden cells. This treatment also reduced fibrosis markers in vivo. We aimed to determine whether this treatment transformed DMFs into adipocyte-like cells in vivo and characterize the PRP factors contributing to this transformation.

METHODS

Dupuytren MFs and normal human dermal fibroblasts were transplanted into the forepaws of rats (Rowett Nude [rnu/rnu]). Two months later, the paws were treated with saline, ASCs + PRP, or Clostridium histolyticum (clinical comparison) once a week for three treatments. The paw tissue was harvested 1 week after each treatment and subjected to Masson trichrome staining, collagen I and III, α-smooth muscle actin (SMA), and perilipin detection by immunohistochemistry. Dupuytren MFs were cocultured with ASCs and PRP or insulin-like growth factor I (IGF-I) or IGF-I-depleted PRP. In addition, the IGF-I receptor was inhibited. Oil Red O or boron-dipyrromethene detected lipid-laden cells.

RESULTS

Rodent paws implanted with DMFs showed enhanced α-SMA expression, imbalanced collagen III:I ratio, and reduced adipocytes compared with normal human dermal fibroblasts. After treatment with ASCs + PRP, DMF paws demonstrated reduced α-SMA, a balanced collagen III:I ratio, and a replenishment of adipocytes. Dupuytren MFs treated with ASCs + IGF-I transformed into adipocyte-like cells in vitro, which was validated by IGF-I-depletion and IGF-I receptor inhibition.

CONCLUSIONS

Adipose-derived stem cells + PRP reduce fibrosis markers and induce adipocyte renewal in vivo. As a PRP component, IGF-I works with ASCs to transform DMFs into adipocyte-like cells in vitro.

CLINICAL RELEVANCE

Identifying an active factor in PRP that synergizes with ASCs to transform DMFs into adipocyte-like cells may contribute to finding a novel therapeutic for Dupuytren disease. Such a treatment may allow for less-extensive surgical intervention coupled with therapeutic injection to reduce the recurrence of Dupuytren disease.

Mechanistic Studies on the Role of IL-17/NLRP3 in Arsenic-Induced Activation of Hepatic Stellate Cells Through Hepatocyte Proptosis

Long-term exposure to arsenic, a prevalent environmental contaminant, has been implicated in the pathogenesis of various hepatic conditions. Hepatic stellate cells (HSCs) are central to the development of liver fibrosis. Recently, the involvement of interleukin-17 (IL-17) and the NOD-like receptor protein 3 (NLRP3) inflammasome in hepatic pathologies has attracted significant research interest. Hepatocyte pyroptosis, a form of programmed cell death, is a critical factor in the occurrence of inflammation. The objective of this study was to investigate the specific roles of IL-17 and NLRP3 in the arsenic-induced activation of HSCs through hepatocyte pyroptosis. We pretreated MIHA cells with MCC950 (1 and 5 μM) and secukinumab (10 and 100 nM) for 4 h, then with NaAsO2 (25 μM) for 24 h at 37 °C under 5% CO2. After incubation, the cell-culture supernatant was collected and mixed with serum-free high-glucose DMEM medium in a 1:1 ratio to prepare the conditioned medium, which was subsequently used for the culture of LX-2 cells. The results showed that exposure to NaAsO2 induced hepatocellular pyroptosis, which led to the release of the inflammatory cytokines IL-18 and IL-1β and subsequent activation of HSCs. Treatment with the inhibitors MCC950 and secukinumab significantly reduced the secretion of Extracellular matrix (ECM) components and attenuated HSC activation. These results demonstrate that blocking the IL-17 and NLRP3 signaling pathways significantly reduces HSC activation and attenuates hepatic fibrogenesis. These results provide novel molecular targets for the prevention and treatment of arsenic-related liver fibrosis.

Ultrasound-Mediated Biomimetic Microbubbles Effectively Reverse LSECs Capillarization and Exert Antiplatelet Therapy in Liver Fibrosis

Liver fibrosis, characterized by excessive tissue remodeling as a response to chronic liver injury, is accompanied by capillarization of liver sinusoidal endothelial cells (LSECs) and activated hepatic stellate cells (HSCs). Simvastatin (Sim) can modulate endothelial function by increasing endothelial nitric oxide synthase (eNOS)-dependent nitric oxide (NO) release, thereby reversing capillarization and attenuating liver fibrosis. However, monotherapy often demonstrates limited therapeutic effectiveness given the complex pathophysiology of liver fibrosis. Herein, a type of multifunctional liposomal microbubbles (MBs) carrying both Sim and platelet membrane (PM) has been designed for drug delivery targeting the inflammatory LSECs, with ultrasound-targeted microbubble destruction (UTMD) to mediate efficient release of these therapeutic agents inside the liver sinusoidal. In rat liver fibrosis model, the multifunctional MBs reverses capillarization through the increase of eNOS-dependent NO production. Subsequently, the MBs adhering to the inflammatory LSECs block the adhesion and activation of inherent platelet (PLT), thereby decreasing platelet-derived growth factor β (PDGF-β) to inhibit the HSCs activation. This study demonstrates the strong therapeutic efficacy of the multifunctional MBs integrating Sim and PLT against liver fibrosis, which highlights a great potential for effectively managing this intractable chronic disease.

ITGA8 deficiency in hepatic stellate cells attenuates CCl4-Induced liver fibrosis via suppression of COL11A1

BACKGROUND AND OBJECTIVE

Liver fibrosis is a pathological process driven by chronic liver injury, characterized by excessive extracellular matrix (ECM) deposition due to hepatic stellate cell (HSC) activation. Integrins are critical regulators of ECM remodeling and HSC activation, yet the role of integrin α8(ITGA8) in liver fibrosis remains unclear. This study aims to investigate the function and underlying mechanisms of HSC-derived ITGA8 in liver fibrosis and evaluate the therapeutic potential of ITGA8-targeted intervention.

METHODS

A CCl4-induced mouse liver fibrosis model and public database analysis were used to assess ITGA8 expression and localization in liver fibrosis. AAV2/6-shItga8 was utilized to selectively silence HSC-derived ITGA8, and its effects on HSC activation and ECM accumulation were examined. In addition, in vitro ITGA8 knockdown combined with proteomic analysis was performed to explore the molecular mechanisms linking ITGA8 to ECM remodeling.

RESULTS

ITGA8 expression was significantly upregulated in fibrotic liver tissues across different etiologies, with a strong colocalization with HSCs. Silencing ITGA8 using AAV2/6-shItga8 effectively reduced liver fibrosis, as indicated by decreased hepatic inflammation, lower serum ALT levels, reduced inflammatory cell infiltration, and downregulated expression of pro-inflammatory cytokines. Fibrosis markers, including Sirius Red staining, type I collagen deposition, and α-SMA expression, were all reduced upon Itga8 silencing. Proteomic analysis revealed that ITGA8 regulates liver fibrosis through the ECM-receptor interaction pathway, with COL11A1 identified as a key downstream target. ITGA8 knockdown significantly suppressed COL11A1 expression, and reduced HSC-mediated collagen contraction, suggesting that ITGA8 contributes to ECM cross-linking and fibrosis progression via COL11A1 regulation.

CONCLUSION

This study demonstrates that HSC-derived ITGA8 promotes ECM accumulation and liver fibrosis progression by regulating COL11A1. Targeted silencing of ITGA8 via AAV2/6-shItga8 effectively alleviates liver fibrosis, providing new insights into ITGA8 as a potential therapeutic target for antifibrotic treatment.

Mindin orchestrates the macrophage-mediated resolution of liver fibrosis in mice

BACKGROUND & AIMS

Liver disease that progresses to cirrhosis is an enormous health problem worldwide. The extracellular matrix protein Mindin is known to have immune functions, but its role in liver homeostasis remains largely unexplored. We aimed to characterize the role of Mindin in the regulation of liver fibrosis.

APPROACH & RESULTS

Mindin was upregulated in mice with carbon tetrachloride (CCl4) or thioacetamide (TAA)-induced liver fibrosis, and was primarily expressed in hepatocytes. Global Mindin knockout mice were generated, which were susceptible to liver fibrosis. Notably, Mindin failed to activate hepatic stellate cells directly; however, it played a role in promoting the recruitment and phagocytosis of macrophages, and caused a phenotypic switch toward restorative macrophages during liver fibrosis. Furthermore, Mindin was found to bind to the αM-I domain of CD11b/CD18 heterodimeric receptors. To further explore this mechanism, we created Mindin and CD11b double-knockout (DKO) mice. In DKO mice, phagocytosis was further reduced, and liver fibrosis was markedly exacerbated.

CONCLUSIONS

Mindin promotes the resolution of liver fibrosis and the Mindin/CD11b axis might represent a novel target for the macrophage-mediated regression of liver fibrosis.

Stem cell exosomes: new hope and future potential for relieving liver fibrosis

Liver fibrosis is a chronic liver injury resulting from factors like viral hepatitis, autoimmune hepatitis, non-alcoholic steatohepatitis, fatty liver disease, and cholestatic liver disease. Liver transplantation is currently the gold standard for treating severe liver diseases. However, it is limited by a shortage of donor organs and the necessity for lifelong immunosuppressive therapy. Mesenchymal stem cells (MSCs) can differentiate into various liver cells and enhance liver function when transplanted into patients due to their differentiation and proliferation capabilities. Therefore, it can be used as an alternative therapy for treating liver diseases, especially for liver cirrhosis, liver failure, and liver transplant complications. However, due to the potential tumorigenic effects of MSCs, researchers are exploring a new approach to treating liver fibrosis using extracellular vesicles (exosomes) secreted by stem cells. Many studies show that exosomes released by stem cells can promote liver injury repair through various pathways, contributing to the treatment of liver fibrosis. In this review, we focus on the molecular mechanisms by which stem cell exosomes affect liver fibrosis through different pathways and their potential therapeutic targets. Additionally, we discuss the advantages of exosome therapy over stem cell therapy and the possible future directions of exosome research, including the prospects for clinical applications and the challenges to be overcome.

Hepatotoxicity from long-term administration of hepatoprotective low doses of oleanolic acid in mice

Oleanolic acid is a triterpenoid existed in many medicinal herbs/plants. Oleanolic acid at low doses are hepatoprotective but at high doses produce cholestasis. This study examined hepatotoxicity potential of low doses of oleanolic acid after log-term administration. Male Kunming mice were orally given oleanolic acid at 100, 200 and 300 μmol/kg daily for 14 weeks. Body weights were monitored, and liver injury was determined via blood biochemistry. Histopathology was examined via H&E, Masson, and Sirius red stains. Oleanolic acid accumulation in plasma and liver was determined by LC-MS and hepatic gene expression by qPCR. Oleanolic acid at low doses did not affect animal body weights, but increased liver index. Serum alanine aminotransferase and alkaline phosphatase were increased, while total bilirubin was unchanged. Chronic oleanolic acid produced hepatocyte degeneration, spot necrosis, and fibrosis. Plasma oleanolic acid was increased more than that in the liver. Oleanolic acid increased hepatic expression of Nrf2, Nqo1, Gclc and Mgst1; Expression of bile acid synthesis genes (Cyp7a1, Cyp8b1, Cyp27a1, Cyp7b1, FXR, SHP) was also suppressed at higher doses. The expression of TGF-β1 and Smad3 was increased, while Smad7 decreased, suggesting the progression to liver fibrosis. High dose of oleanolic acid was less effective in producing these changes, probably due to increased liver injury. Overall, oral administration of low doses of oleanolic acid for 14 weeks produced liver injury and fibrosis. These harmful effects were associated with increased oleanolic acid in plasma and liver, and the disruptions of bile acid metabolism, the Nrf2 and TGF-β/Smad signaling pathways.

Triclosan exposure induces liver fibrosis in mice: The heterogeneous nuclear ribonucleoprotein A1/pyruvate kinase M2 axis drives hepatic stellate cell activation

Triclosan (TCS) is an effective broad-spectrum antibacterial agent. TCS possesses a stable structure, can easily accumulate in the environment, and may have numerous negative impacts on human health. One organ particularly susceptible to TCS damage is the liver; however, the molecular mechanisms underlying TCS-induced liver damage remain unclear. A long-term TCS exposure model was established in C57BL/6 mice through maternal administration from gestation to postnatal 8-week-old. The offspring were randomly assigned to three groups (0, 50, and 100 mg/kg TCS) with six animals per group, ensuring an equal gender distribution (3 males and 3 females). The results showed that TCS-exposed mice exhibited serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase enzyme activities increased by 1.5-2 times when compared with vehicle-treated mice, along with features of liver fibrosis. In the LX-2 cell line, used as an in vitro model, TCS promoted proliferation and migration and induced the activation of hepatic stellate cells (HSCs). The level of pyruvate kinase M2 (PKM2) dimer increased by 200 % in LX-2 cells treated with TCS. PKM2 dimer overexpression stimulated HSC activation, whereas treatment with TEPP-46 (a PKM2 dimer inhibitor) significantly decreased the activation process. The expression of heterogeneous ribonucleoprotein particle A1 (hnRNPA1) was upregulated in the TCS treatment group and promoted the PKM2 expression. Moreover, disruption of the hnRNPA1/PKM2 axis reduced HSC proliferation and migration activated by TCS. Overall, our findings highlighted that TCS could cause liver fibrosis by stimulating the proliferation and migration of HSCs activated via the hnRNPA1/PKM2 axis, providing promising treatment options for TCS-related liver damage.

Non-invasive liver fibrosis markers are increased in obese individuals with non-alcoholic fatty liver disease and the metabolic syndrome

The need for early non-invasive diagnostic tools for chronic liver fibrosis is growing, particularly in individuals with obesity, non-alcoholic fatty liver disease (NAFLD), and the metabolic syndrome (MetS) since prevalence of these conditions is increasing. This case-control study compared non-invasive liver fibrosis markers in obesity with NAFLD and MetS (NAFLD-MetS, n = 33), in obese (n = 28) and lean (n = 27) control groups. We used MRI (T1 relaxation times (T1) and liver stiffness), circulating biomarkers (CK18, PIIINP, and TIMP1), and algorithms (FIB-4 index, Forns score, FNI, and MACK3 score) to assess their potential in predicting liver fibrosis risk. We found that T1 (892 ± 81 ms vs. 818 ± 64 ms, p < 0.001), FNI (15 ± 12% vs. 9 ± 7%, p = 0.018), CK18 (166 ± 110 U/L vs. 113 ± 41 U/L, p = 0.019), and MACK3 (0.18 ± 0.15 vs. 0.05 ± 0.04, p < 0.001) were higher in the NAFLD-MetS group compared with the obese control group. Moreover, correlations were found between CK18 and FNI (r = 0.69, p < 0.001), CK18 and T1 (r = 0.41, p < 0.001), FNI and T1 (r = 0.33, p = 0.006), MACK3 and FNI (r = 0.79, p < 0.001), and MACK3 and T1 (r = 0.50, p < 0.001). We show that liver fibrosis markers are increased in obese individuals with NAFLD and MetS without clinical signs of liver fibrosis. More studies are needed to validate the use of these non-invasive biomarkers for early identification of liver fibrosis risk.

Co-Exposure to Polystyrene Microplastics and Bisphenol A Contributes to the Formation of Liver Fibrosis in Mice through Inhibition of the BMAL1/E-Cad Signaling Pathway

The food safety risks posed by exposure to polystyrene microplastics (PS-MPs) and bisphenol A (BPA) have become an issue worldwide. However, the toxic effects of PS-MPs and BPA coexposure on the mammalian liver remain elusive. In this study, we found that PS-MPs and BPA coexposure have synergistic toxic effects on AML12 cells and the mouse liver. Histopathological staining revealed excessive accumulation of the extracellular matrix in the coexposure liver. Co-exposure to PS-MPs and BPA downregulated Bmal1 and E-cad both in vitro and in vivo. Additionally, Bmal1-/- AML12 cells and liver-specific Bmal1-/- mice exhibited significantly reduced E-cad levels, with no significant reduction under PS-MPs and BPA coexposure. Notably, overexpression of BMAL1 and CLOCK significantly enhanced luciferase activity driven by the E-cad gene intron region (containing an E-box cis-element). These results demonstrated that coexposure to PS-MPs and BPA contributed to the development of liver fibrosis by inhibiting the BMAL1/E-cad signaling pathway.

Fluorofenidone attenuates choline-deficient, l-amino acid-defined, high-fat diet-induced metabolic dysfunction-associated steatohepatitis in mice

Metabolic dysfunction-associated steatohepatitis (MASH), a severe form of metabolic dysfunction-associated steatotic liver disease (MASLD), involves hepatic lipid accumulation, inflammation, and fibrosis. It can progress to cirrhosis or hepatocellular carcinoma without timely treatment. Current treatment options for MASH are limited. This study explores the therapeutic effects of fluorofenidone (AKF-PD), a novel small-molecule compound with antifibrotic and anti-inflammatory properties, on MASH in mouse model. Mice fed a choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD) were treated with AKF-PD, resulting in reduced serum ALT, AST, hepatic lipid accumulation, liver inflammation, and fibrosis. Network pharmacology and RNA-sequencing analyses suggested that AKF-PD influenced multiple metabolic, inflammatory, and fibrosis-related pathways. Further experiments verified that AKF-PD activated hepatic AMPK signaling, leading to the inhibition of the downstream SREBF1/SCD1 pathway and the activation of autophagy. Additionally, AKF-PD suppressed the expression of various inflammatory factors, reduced macrophage infiltration, and inhibited NLRP3 inflammasome activation. Moreover, AKF-PD attenuated liver fibrosis by inhibiting TGFβ1/SMAD signaling. In conclusion, this study reveals that AKF-PD effectively decreases hepatic lipid accumulation, liver inflammation and fibrosis in a CDAHFD-induced MASH model, positioning AKF-PD as a promising candidate for the treatment of MASH.

Mechanisms of rifaximin inhibition of hepatic fibrosis in mice with metabolic dysfunction associated steatohepatitis through the TLR4/NFκB pathway

Metabolic dysfunction-associated steatohepatitis (MASH) has become a serious public health problem, posing an increasingly dangerous threat to human health owing to its increasing prevalence and accompanying intra- and extrahepatic adverse outcomes. Rifaximin is considered to have therapeutic potential for MASH; however, its efficacy remains controversial. Our study aimed to observe the ameliorative effects of rifaximin and explore its possible mechanisms at the cellular level. 1. 42 male C57BL/6J mice were divided into 3 groups, the CON group and MCD group were fed with normal feed and MCD feed for 12 weeks respectively, and the MCD + RFX group was treated with rifaximin by gavage for 4 weeks on the basis of MCD feed. Hematoxylin-eosin staining, Sirius red staining and immunohistochemical staining were used to observe the histopathological changes of liver and intestine. Differences in liver transaminases, inflammatory factors, fibrosis indexes and intestinal tight junction proteins were compared among the 3 groups of mice. 2. A MASH cell model was constructed by inducing HepG2 cells with free fatty acids to observe the effects of rifaximin on MASH in vitro. In addition, the effects of rifaximin on TLR4/NF-κB signaling pathway were explored by applying TLR4 agonist LPS and TLR4 inhibitor TAK-242. Hepatic histopathology was significantly improved in MASH mice after rifaximin treatment, and their serum alanine aminotransferase and aspartate aminotransferase levels were (72.72 ± 5.68) U/L and (222.8 ± 11.22) U/L, respectively, which were significantly lower than those in the MCD group [(293.3 ± 10.69) U/L and (414.1 ± 36.29) U/L, P < 0.05], and the levels of inflammatory factors and fibrosis indicators were reduced. Rifaximin ameliorated intestinal barrier injury with increased expression of intestinal tight junction protein ZO-1 in the MCD + RFX group of mice, and the concentration of LPS-binding proteins (4.92 ± 0.55 vs. 15.82 ± 1.71, P < 0.05) was lower than that in the MCD group. In the NASH cell model, rifaximin similarly exerted inhibitory effects on its inflammatory factors and TLR4/NF-κB signaling pathway. Application of TLR4 inhibitors weakened the inhibitory effect of rifaximin on MASH. Our study supports rifaximin as a potential treatment for MASH, with potential mechanisms related to improving intestinal barrier integrity and downregulating the TLR4/NF-κB signaling pathway.

Ceramide and DNA damage in liver fibrosis: Exploring the implications of eicosapentaenoic acid encapsulation in cellulose nanocrystals

Ceramide plays a crucial role in promoting liver fibrosis by inducing apoptosis and inflammation in hepatocytes. Oxidative stress accelerates fibrosis by elevating levels of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), an indicator for the damage of DNA. We aimed to evaluate the efficacy of eicosapentaenoic acid encapsulated in cellulose nanocrystals (EPA-CNC) in inhibiting ceramide accumulation and reducing urinary 8-OHdG levels, thus providing protective effects against the progression of liver fibrosis. In this study, twenty-four adult male Wistar albino rats were allocated into a negative control group, a group with liver fibrosis induced by diethylnitrosamine (DEN), and a group with DEN-induced liver fibrosis treated simultaneously with EPA-CNC. Key parameters assessed included liver paraoxonase-1 (PON-1), plasma interleukin-6 (IL-6), plasma ceramide, liver hydroxyproline (Hyp) content, and urinary 8-OHdG. DEN-induced liver fibrosis led to a significant increase in inflammatory markers, including ceramide, IL-6, and notably urinary 8-OHdG. This was accompanied by a decrease in PON-1 activity and increased collagen deposition in liver tissues (Hyp content). Histopathological analysis revealed a substantial loss of liver architecture, with inflammation and fibrosis surrounding necrotic areas. In contrast, treatment with encapsulated EPA-CNC resulted in a significant decrease in plasma ceramide, IL-6, liver Hyp content, and urinary 8-OHdG levels, along with an improvement in liver PON-1 activity. Histopathological findings showed nearly normal liver architecture. In conclusion, increased levels of ceramide and urinary 8-OHdG could serve as indicators of ongoing hepatocellular damage due to their positive correlations with fibrotic markers. Encapsulated EPA-CNC may offer a promising approach for halting oxidative stress and inflammation in liver fibrosis.

Possible Role of Platelets in the Development and Progression of Non-Alcoholic Fatty Liver Disease

To date, an increasing body of evidence supports the potential role of activated platelets in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). This is likely due to their ability to secrete biologically active substances that regulate liver regeneration processes, ensure hemostasis, and participate in the immune response. Additionally, several studies have demonstrated the efficacy of antiplatelet agents in reducing inflammation, the severity of liver fibrosis, and the progression of fibrosis in non-alcoholic steatohepatitis (NASH). Since NAFLD is not an independent indication for antiplatelet therapy, the primary evidence regarding their efficacy in NAFLD has been derived from studies using animal models of NAFLD or in patients with concomitant cardiovascular diseases. This narrative review will discuss the main functions of platelets, their unique interactions with liver cells, and the outcomes of these interactions, as well as the results of studies evaluating the efficacy and safety of antiplatelet therapy in patients with NAFLD.

Novel RORγt inverse agonists limit IL-17-mediated liver inflammation and fibrosis

Liver fibrosis is a global health problem. IL-17A has proven profibrogenic properties in liver disease making it an interesting therapeutic target. IL-17A is regulated by RORγt and produced by Th17 CD4+ and γδ-T cells. We hypothesized that blocking IL-17A production will limit fibrosis progression by reducing recruitment of inflammatory cells. Herein, we tested the therapeutic potential of 2 novel RORγt inverse agonists (2,3 derivatives of 4,5,6,7-tetrahydro-benzothiophene) in a mouse model of CCl4-induced liver injury. C57BL/6 mice received 2 weekly injections of CCl4 for 4 weeks. As of week 3, mice were treated with the 2 novel inverse agonists (TF-S10 and TF-S14) and GSK805 as a positive control. Mice treated with the inverse agonists showed reduced immune cells infiltrate around the portal and central veins. TF-S14 significantly reduced AST levels (P < 0.05), and all inhibitors led to an improvement in relative liver weight (liver index). Flow cytometry analysis demonstrated that all inhibitors reduced the numbers of intrahepatic lymphocytes (CD4+, CD8+, and γδ-T cells, P < 0.05), and myeloid (CD11b+) cells (P = 0.04), most significantly eosinophils (P < 0.05). Furthermore, IL-17A production by CD4+ and γδ-T cells was diminished (P < 0.05 and P < 0. 01, respectively). Finally, livers from inhibitors-treated mice showed decreased markers of hepatic stellate cell activation (desmin and ɑ-smooth muscle actin [ɑ-SMA]) and significantly reduced expression of the profibrogenic genes (Col1a1, Acta, Loxl2, and Tgfβ) (P < 0.001). This was accompanied by diminished collagen deposition as measured by Picrosirius Red staining (P < 0.001). In conclusion, our results suggest that inhibition of the IL-17A pathway could be a promising therapeutic strategy for liver fibrosis.

Chondroitin Sulfate-Based Imatinib Nanoparticles Targeting Activated Hepatic Stellate Cells Against Hepatic Fibrosis

Background: Activated hepatic stellate cells (aHSCs) play a significant role during the onset of hepatic fibrosis, ultimately leading to excessive deposition of extracellular matrix (ECM) and other typical pathological features, and thus have become a popular target for the treatment of hepatic fibrosis. However, current aHSC-centric therapy strategies achieve unsatisfactory results, mainly due to the lack of approved anti-fibrosis drugs and sufficiently efficient aHSC-targeted delivery systems. In this study, our aim was to develop an Imatinib-loaded nanoparticle delivery system based on a chondroitin sulfate derivative to enhance aHSC targeting efficiency, improve the therapeutic effect for hepatic fibrosis, and investigate the underlying mechanism. Methods: The carboxyl group of chondroitin sulfate and the amino group of 1-hexadecylamine were linked by an amide bond in this study to produce the amphiphilic carrier CS-HDA. Then, the Imatinib-loaded nanoparticles (IM-CS NPs) were designed to efficiently target aHSCs through CD44-mediated endocytosis and effectively inhibit HSC overactivation via PDGF and TGF-β signaling pathways. Results: Both in vitro cellular uptake experiments and in vivo distribution experiments demonstrated that CS-HDA-modified nanoparticles (IM-CS NPs) exhibited a better targeting ability for aHSCs, which were subsequently utilized to treat carbon tetrachloride-induced hepatic fibrosis mouse models. Finally, significant fibrosis resolution was observed in the carbon tetrachloride-induced hepatic fibrosis mouse models after tail vein injection of the IM-CS NPs, along with their outstanding biocompatibility and biological safety. Conclusions: IM-loaded NPs based on an amphiphilic CS derivative have remarkable antifibrotic effects, providing a promising avenue for the clinical treatment of advanced hepatic fibrosis.

Design, synthesis, and biological evaluation of a potent and orally bioavailable FGFRs inhibitor for fibrotic treatment

Organ fibrosis, such as lung fibrosis and liver fibrosis, is a progressive and fatal disease. Fibroblast growth factor receptors (FGFRs) play an important role in the development and progression of fibrosis. Through scaffold hopping, bioisosteric replacement design, and structure-activity relationship optimization, we developed a series of highly potent FGFRs inhibitors, and the indazole-containing candidate compound A16 showed potent kinase activity comparable to that of AZD4547. In addition, A16 effectively suppressed the activation of lung fibroblasts and hepatic stellate cells (HSCs) induced by TGF-β1, leading to a reduction in collagen deposition. Notably, A16 exhibited potent anti-fibrotic effects through the inhibition of the FGFR pathway in vitro. Compound A16 also showed reasonable pharmacokinetic properties (F = 21.84 %) and favorable cardiac safety (hERG IC50 > 20 μM). Moreover, in models of pulmonary fibrosis, A16 ameliorated (in the prevention model) and reversed (in the treatment model) bleomycin-induced lung fibrosis, as well as mitigated inflammatory immune response in the lung. Furthermore, in the CCl4-induced liver fibrosis model, when A16 was administrated orally at a dose of 30 mg/kg/day for 3 weeks, it effectively improved liver function, restored damaged liver structures, and reduced collagen deposition. Taken together, these results suggest that A16 could be a potential drug candidate for the treatment of organ fibrosis.

Solid-State Fermented Cereals: Increased Phenolics and Their Role in Attenuating Liver Diseases

Liver diseases, a leading cause of global mortality, necessitate effective dietary strategies. Fermented cereals, traditionally recognized for benefits in glucose regulation, lipid profiles, and antioxidant activity, hold potential for managing conditions such as type 2 diabetes, hypertension, and obesity. However, their specific impact on liver health requires further investigation. Fermentation, particularly solid-state fermentation (SSF), enhances the bioavailability of beneficial compounds, including phenolics. This review summarizes recent studies on the phenolic content of fermented cereals, highlighting variations based on microbial strains and cereal types. It examines the hepatoprotective effects of these phenolics, drawing on in vivo and in vitro research. Furthermore, the review explores recent findings on the impact of fermented cereals on liver health and related diseases. This work provides a foundation for future research exploring fermented cereals as a dietary intervention for liver disease prevention and management.

Deep proteome profiling of metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects roughly 1 in 3 adults and is a leading cause of liver transplants and liver related mortality. A deeper understanding of disease pathogenesis is essential to assist in developing blood-based biomarkers.

METHODS

Here, we use data-independent acquisition mass spectrometry to assess disease-state associated protein profiles in human liver, blood plasma, and white adipose tissue (WAT).

RESULTS

In liver, we find that MASLD is associated with an increased abundance of proteins involved in immune response and extracellular matrix (ECM) and a decrease in proteins involved in metabolism. Cell type deconvolution of the proteome indicates liver endothelial and hepatic stellate cells are the main source of ECM rearrangements, and hepatocytes are the major contributor to the changes in liver metabolism. In the blood, profiles of several MASLD-associated proteins correlate with expression in WAT rather than liver and so could serve as suitable liver disease predictors in a multi-protein panel marker. Moreover, our proteomics-based logistic regression models perform better than existing methods for predicting MASLD and liver fibrosis from human blood samples.

CONCLUSIONS

Our comprehensive proteomic analysis deepens the understanding of liver function and MASLD pathology by elucidating key cellular mechanisms and multi-organ interactions, and demonstrates the robustness of a proteomics-based biomarker panel to enhance diagnosis of MASLD and significant fibrosis.

Optimization of culture conditions to generate vascularized multi-lineage liver organoids with structural complexity and functionality

Hepatic organoids (HOs), primarily composed of hepatobiliary cells, do not represent the pathogenesis of liver diseases due to the lack of non-parenchymal cells. Multi-lineage liver organoids (mLOs) containing various cell types found in the liver offer a promising in vitro disease model. However, their structural complexity remains challenging to achieve due to the difficulty in optimizing culture conditions that meet the growth need of all component cell types. Here, we demonstrate that cystic HOs generated from hPSCs can be expanded long-term and serve as a continuous source for generating complex mLOs. Assembling cystic HOs with hPSC-derived endothelial and hepatic stellate cell-like cells under conventional HO culture conditions failed to support the development of multiple cell types within mLOs, resulting in biased differentiation towards specific cell types. In contrast, modulating the cAMP/Wnt/Hippo signaling pathways with small molecules during assembly and differentiation phases efficiently generate mLOs containing both hepatic parenchymal and non-parenchymal cells. These mLOs exhibited structural complexity and functional maturity, including vascular network formation between parenchymal lobular structures, cell polarity for bile secretion, and the capacity to respond to fibrotic stimuli. Our study underscores the importance of modulating signaling pathways to enhance mLO structural complexity for applications in modeling liver pathologies.

Hepatic Stellate Cells Functional Heterogeneity in Liver Cancer

Hepatic stellate cells (HSCs) are the liver's pericytes, and play key roles in liver homeostasis, regeneration, fibrosis, and cancer. Upon injury, HSCs activate and are the main origin of myofibroblasts and cancer-associated fibroblasts (CAFs) in liver fibrosis and cancer. Primary liver cancer has a grim prognosis, ranking as the third leading cause of cancer-related deaths worldwide, with hepatocellular carcinoma (HCC) being the predominant type, followed by intrahepatic cholangiocarcinoma (iCCA). Moreover, the liver hosts 35% of all metastatic lesions. The distinct spatial distribution and functional roles of HSCs across these malignancies represent a significant challenge for universal therapeutic strategies, requiring a nuanced and tailored understanding of their contributions. This review examines the heterogeneous roles of HSCs in liver cancer, focusing on their spatial localization, dynamic interactions within the tumor microenvironment (TME), and emerging therapeutic opportunities, including strategies to modulate their activity, and harness their potential as targets for antifibrotic and antitumor interventions.

Ether bond-modified lipid nanoparticles for enhancing the treatment effect of hepatic fibrosis

Lipid nanoparticle (LNP)-mediated RNA delivery holds significant potential for the treatment of various liver diseases. Ionizable lipids play a crucial role in the formulation of LNPs and directly influence their delivery efficiency. In this study, we introduced an innovative concept by incorporating an ether bond into the hydrophobic tail of ionizable lipids for the first time. Three ionizable lipids, namely, ND-O1, ND-O2, and ND-O3, were synthesized based on 1-octylnonyl 8-[(2-hydroxyethyl)-[8-(nonyloxy)-8-oxooctyl] amino] octanoate (Lipid M). The efficacy of lipids-based LNPs for the delivery of the heat shock protein 47 (HSP47)-targeted siRNA to the liver was investigated. Compared to Lipid M-based LNP (LNP-M), it was observed that ND-O1 based LNP (LNP-O1) exhibited enhanced siRNA transfection efficiency in activated fibroblasts. In the fibrosis mice, LNP-O1 effectively suppressed HSP47 expression by approximately 84%, which was three times more effective than LNP-M, resulting in a significant decrease of collagen deposition and an amelioration of liver fibrosis. These findings highlighted the potential application of ND-O1 as an ionizable lipid for enhancing the efficient delivery of LNPs-delivered siRNA to the liver. Furthermore, this ionizable lipid design strategy offers a promising avenue for the improvement of the LNP delivery system.

Stable Transmission of DNA Methylation Epimutations from Germlines to the Liver and Their Association with Fatty Liver Disease in Medaka

Background

Environmental stressors can induce heritable traits in organisms across phyla, with distinct epigenetic alterations in gametes and phenotypic outcomes across several generations. However, the mechanisms underlying such intergenerational inheritance, mainly from the germline to the germline and from the germline to the soma, are enigmatic, given that postfertilization embryos and germline cells reprogram the epigenome in each generation to gain their cellular identity. Here, we report stable germline transmission of differential DNA methylation alterations (epimutations) and their associations with nonalcoholic fatty liver disease (NAFLD) in medaka exposed to a model estrogenic chemical but a ubiquitous environmental contaminant, bisphenol A (BPA).

Results

Ancestral BPA exposure in the F0 generation led to advanced NAFLD in the unexposed grandchildren generation (F2) of medaka. The F2 liver transcriptome and histopathology revealed a severe NAFLD phenotype in females. Whole-genome bisulfite sequencing of the sperm and liver revealed a gradual shift in promoter methylation from F0 sperm (hypomethylated) to F1 sperm (mix of hypo- and hypermethylated) and F2 liver (predominantly hypermethylated). Many differentially methylated promoters (DMPs) overlapped in F0 sperm, F1 sperm, and F2 liver, regardless of sex. In females, stable transmission of 1511 DMPs was found across three generations, which are associated with protein-coding genes, miRNAs, and others and linked to NAFLD and nonalcoholic steatohepatitis (NASH). Among them, 27 canonical genes maintained consistently hypermethylated promoters across three generations, with significant downregulation of their expression and enrichment in NAFLD-related pathways, mainly fat digestion, glycerolipid metabolism, and steroid biosynthesis.

Conclusions

The present results demonstrate stable inter- and transgenerational germline-to-germline and germline-to-soma transmission of environmentally induced DNA epimutations with F0 and F1 gametic epimutations, predicting the F2 liver phenotype-a clear transgenerational passage of the disease phenotype in medaka.

HIV-1 Tat-induced disruption of epithelial junctions and epithelial-mesenchymal transition of oral and genital epithelial cells lead to increased invasiveness of neoplastic cells and the spread of herpes simplex virus and cytomegalovirus

Human immunodeficiency virus (HIV-1) transactivator Tat is a unique multi-functional viral protein secreted by infected cells. Although its primary function is to promote HIV-1 transcription, secreted Tat interacts with neighboring cells and induces numerous disease-associated pathological changes. Despite the substantial reduction of viral load and disease burden, Tat expression and secretion persist in people living with HIV who are undergoing treatment with highly effective combination antiretroviral therapy (cART). Tat interacts with both oral and genital epithelial cells and impairs their mucosal barrier functions, which facilitates the entry of other pathogenic viruses. Tat-mediated interactions with both human papillomavirus (HPV) -infected and HPV-negative neoplastic epithelial cells lead to epithelial-mesenchymal transition and increased invasiveness of malignant cells. Likewise, Tat-induced disruption of oral epithelial cell junctions leads to herpes simplex virus-1 (HSV-1) infection and spread via exposure of its receptor, nectin-1. HIV-1 Tat facilitates infection and spread of human cytomegalovirus (HCMV) by activating mitogen-activated protein kinases (MAPK) and promoting NF-κB signaling, both critical for the replication and production of progeny virions. HIV extracellular Tat also plays a critical role in human herpesvirus 8 (HHV8) -caused Kaposi sarcoma (KS) pathogenesis by synergizing with HHV-8 lytic proteins and promoting the proliferation, angiogenesis, and migration of endothelial cells. Collectively, these findings emphasize the critical impact of HIV-1 Tat on HIV/AIDS pathogenesis during the cART era and highlight the need for further research on the molecular mechanisms underlying Tat-mediated interactions with oral and genital mucosal epithelial cells.

Trajectory analysis of hepatic stellate cell differentiation reveals metabolic regulation of cell commitment and fibrosis

Defining the trajectory of cells during differentiation and disease is key for uncovering the mechanisms driving cell fate and identity. However, trajectories of human cells remain largely unexplored due to the challenges of studying them with human samples. In this study, we investigate the proteome trajectory of iPSCs differentiation to hepatic stellate cells (diHSCs) and identify RORA as a key transcription factor governing the metabolic reprogramming of HSCs necessary for diHSCs' commitment, identity, and activation. Using RORA deficient iPSCs and pharmacologic interventions, we show that RORA is required for early differentiation and prevents diHSCs activation by reducing the high energetic state of the cells. While RORA knockout mice have enhanced fibrosis, RORA agonists rescue multi-organ fibrosis in in vivo models. Notably, RORA expression correlates negatively with liver fibrosis and HSCs activation markers in patients with liver disease. This study reveals that RORA regulates cell metabolic plasticity, important for mesoderm differentiation, pericyte quiescence, and fibrosis, influencing cell commitment and disease.

Focal adhesion kinase promotes aerobic glycolysis in hepatic stellate cells via the cyclin D1/c-Myc/MCT-1 pathway to induce liver fibrosis

Hepatic stellate cells (HSCs) transdifferentiate into myofibroblasts during liver fibrosis and exhibit increased glycolysis. Phosphorylated focal adhesion kinase (FAK) (pY397-FAK) promotes monocarboxylate transporter 1 (MCT-1) expression in HSCs to increase aerobic glycolysis and cause liver fibrosis. A combined multiomics analysis of C57BL/6 mice with tetrachloromethane (CCl4)-induced liver fibrosis was performed to identify the downstream FAK signaling pathway. The effect of the FAK inhibitor PF562271 on CCl4-induced liver fibrosis was explored by immunofluorescence of liver tissues. The migration, proliferation and aerobic glycolysis of LX-2 cells after stimulation and activation by transforming growth factor beta-1 (TGF-β1) or suppression by PF562271 was assessed in vitro. Multiomics analysis of a successfully generated CCl4-induced liver fibrosis mouse model was performed. FAK and cyclin D1 were significantly enriched in mice with CCl4-induced liver fibrosis. In vivo, the MCT-1 and alpha smooth muscle actin (α-SMA) levels were increased in mice with CCl4-induced liver fibrosis, and MCT-1 and α-SMA expression decreased after PF562271 treatment. In vitro, PF562271 alleviated TGF-β1-induced LX-2 activation. LX-2 cells showed diminished migration, proliferation, and aerobic glycolysis after PF562271 intervention. FAK promotes aerobic glycolysis in LX-2 cells through the cyclin D1/c-Myc/MCT-1 pathway, thereby increasing liver fibrosis.

Curcumol Attenuates Portal Hypertension and Collateral Shunting Via Inhibition of Extrahepatic Angiogenesis in Cirrhotic Rats

Liver cirrhosis can cause disturbances in blood circulation in the liver, resulting in impaired portal blood flow and ultimately increasing portal venous pressure. Portal hypertension induces portal-systemic collateral formation and fatal complications. Extrahepatic angiogenesis plays a crucial role in the development of portal hypertension. Curcumol is a sesquiterpenoid derived from the rhizome of Curcumae Rhizoma and has been confirmed to alleviate liver fibrosis by inhibiting angiogenesis. Therefore, our study was designed to explore the effects of curcumol on extrahepatic angiogenesis and portal hypertension. To induce cirrhosis, Sprague Dawley rats underwent bile duct ligation (BDL) surgery. Rats received oral administration with curcumol (30 mg/kg/d) or vehicle (distilled water) starting on day 15 following surgery, when BDL-induced liver fibrosis had developed. The effect of curcumol was assessed on day 28, which is the typical time of BDL-induced cirrhosis. The results showed that curcumol markedly reduced portal pressure in cirrhotic rats. Curcumol inhibited abnormal splanchnic inflow, mitigated liver injury, improved liver fibrosis, and attenuated portal-systemic collateral shunting in cirrhotic rats. These protective effects were partially attributed to the inhibition on mesenteric angiogenesis by curcumol. Mechanically, curcumol partially reversed the BDL-induced activation of the JAK2/STAT3 signaling pathway in cirrhotic rats. Collectively, curcumol attenuates portal hypertension in liver cirrhosis by suppressing extrahepatic angiogenesis through inhibiting the JAK2/STAT3 signaling pathway.

Quantitative pharmacodynamics functional evaluation of Chinese medicine Qizhu formula in mice with dynamic near-infrared photoacoustic imaging

Background & Aims

Effective anti-fibrotic drugs and new non-invasive evaluation methods for liver fibrosis (LF) are urgently needed. Our study aimed to evaluate the histological effects of the Qizhu (QZ) formula on LF and to explore a non-invasive Near-infrared photoacoustic imaging (NIR-PAI) kinetic model for liver function detection and pharmacodynamic evaluation.

Methods

C57BL/6 J mice were randomly divided into six groups (n=6). An LF model was induced by CCl4 for 8 weeks, followed by an 8-week treatment period. Histological and serological parameters were assessed, and indocyanine green (ICG) metabolism (maximum peak time [Tmax] and half-life [T1/2]) was monitored by NIR-PAI. Spearman correlation analysis was conducted to evaluate correlations.

Results & Conclusions

Histological and serological results confirmed the anti-fibrotic effects of QZ. NIR-PAI kinetic parameters indicated that QZ shortened the Tmax and T1/2 of ICG. There were good correlations between ICG metabolism and liver histopathology. The non-invasive NIR-PAI kinetic model shows potential in liver function detection and pharmacodynamic evaluation.

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.

Advances in liver organoids: replicating hepatic complexity for toxicity assessment and disease modeling

The lack of in vivo accurate human liver models hinders the investigation of liver-related diseases, injuries, and drug-related toxicity, posing challenges for both basic research and clinical applications. Traditional cellular and animal models, while widely used, have significant limitations in replicating the liver's complex responses to various stressors. Liver organoids derived from human pluripotent stem cells, adult stem cells primary cells, or tissues can mimic diverse liver cell types, major physiological functions, and architectural features. Recent advancements in the field have shown that some liver organoids have sufficient accuracy to replicate specific aspects of the human liver's complexity. This review highlights recent progress in liver organoid research, with a particular emphasis on their potential for toxicity assessment and disease modeling. The intrinsic advantages of liver organoids include higher sensitivity and suitability for long-term studies, which enhance the predictive value in drug and nanomaterial toxicity testing. The integration of liver organoids with microfluidic devices enables the simulation of the liver microenvironment and facilitates high-throughput drug screening. The liver organoids also serve as ideal platforms for studying liver diseases such as hepatitis, liver fibrosis, viral liver diseases, and monogenic diseases. Additionally, this review discusses the advantages and limitations of liver organoids along with potential avenues for future research.

The interactive role of microRNA and other non-coding RNA in hepatitis B (HBV) associated fibrogenesis

One of the outstanding features of chronic hepatitis B infection (CHB) is its strong association with liver fibrosis. CHB induced inflammation and injury trigger multiple biochemical and physical changes that include the promotion of a wide range of cytokines, chemokines and growth factors that activate hepatic stellate cells (HSCs) CHB induced activation of hepatic stellate cells (HSCs) is regarded as a central event in fibrogenesis to directly promote the synthesis of myofibroblasts and the expression of a range of materials to repair injured liver tissue. Fibrogenesis is modulated by the mainstream epigenetic machinery, as well as by non-coding RNA (ncRNA) that are often referred to as an ancillary epigenetic response to fine tune gene expression. Although extensive research has explained the regulatory role of ncRNA in liver fibrogenesis, most of this research relates to non-CHB etiologies. This review paper outlines the complex interactive regulatory role of microRNA (miRNA) and their interaction with long non-coding RNA (lncRNA), circular RNA (circRNA) and the mainstream epigenetic machinery in CHB induced liver fibrosis. The paper also illustrates some of the difficulties involved in translating candidate ncRNA into approved drugs or diagnostic tools. In conclusion, the important regulatory role of ncRNA in CHB induced liver fibrosis warrants further investigation to exploit their undoubted potential as diagnostic and therapeutic agents.

Design and Synthesis of Dual Galectin-3 and EGFR Inhibitors Against Liver Fibrosis

Liver fibrosis, mainly arising from chronic viral or metabolic liver diseases, is a significant global health concern. There is currently only one FDA-approved drug (Resmetirom) in the market to combat liver fibrosis. Both galectin-3 and epidermal growth factor receptor (EGFR) play important roles in liver fibrosis, while galectin-3 may interact with EGFR. Galectin-3 inhibitors, typically lactose or galactose derivatives may inhibit liver fibrosis. We hypothesized that targeting both galectin-3 and EGFR may have better effect against liver fibrosis. Here, EGFR inhibitor erlotinib was used in a series of designed galectin-3 inhibitors after hybridization with the pharmacophore structure in reported galectin-3 inhibitors to impede hepatic stellate cells (HSCs) activation by a typical method of click chemistry. Bioactivity test results showed that compound 29 suppressed TGF-β-induced upregulation of fibrotic markers (α-SMA, fibronectin-1, and collagen I). The preferred compound 29 displayed better binding to galectin-3 (KD=52.29 μM) and EGFR protein (KD=3.31 μM) by SPR assay. Further docking studies were performed to clarify the possible binding mode of compound 29 with galectin-3 and EGFR. Taken together, these results suggested that compound 29 could be a potential dual galectin-3 and EGFR inhibitor as leading compound for anti-liver fibrosis new drug development.

A novel pectin-like polysaccharide from Crocus sativus targets Galectin-3 to inhibit hepatic stellate cells activation and liver fibrosis

Liver fibrosis may lead to cirrhosis and even cancer without effective clinical medicine available. Previous studies demonstrated that galactan-containing pectins or pectin-like polysaccharides might target Galectin-3 (Gal-3) to impede fibrosis. This research aims to discover novel pectin-like galactan to interfere with fibrosis for potential new drug development. Thus, we purify a novel homogeneous Rhamnogalacturonan-I like polysaccharide with galactan input, XHH2, from the Crocus sativus flower. XHH2 (MW: 35.7 kDa) consists of rhamnose, galacturonic acid, galactose, and arabinose in ratios of 6.6: 6.1: 25.2: 12.1. The backbone of XHH2 comprises 1, 3, 6-Gal and 1, 3, 4-GalA, with branches at O-3 of 1, 3, 6-Gal and O-4 of 1, 3, 4-GalA. O-3 branches include 1, 3-Gal, 1, 4-Gal, 1, 6-Gal, T-Gal, and T-Glc, while O-4 branches consist of 1, 2, 4-Rha, 1, 4-GalA, 1, 5-Ara, T-Ara, T-Gal, and T-α-HexA. Surface plasmon resonance measurement shows that XHH2 binds to both Gal-3 and integrin β1 to block Gal-3/integrin β1 interaction. Mechanism studies further suggest that XHH2 inactivates hepatic stellate cells (HSCs) via disturbing the Gal-3/Integrin-β1/FAK pathway to alleviate liver injury and fibrosis in vitro & in vivo. XHH2 shows a favorable drug safety in the acute toxicity test of oral administration of XHH2 in mice. Overall, XHH2 is an active ingredient against liver fibrosis by targeting the interaction between Gal-3 and Integrin-β1.

PLIN5 contributes to lipophagy of hepatic stellate cells induced by inorganic arsenic

Arsenic exposure triggers the activation of hepatic stellate cells (HSCs), resulting in liver fibrosis (LF). A significant decrease in lipid droplets marks the activation of HSCs. However, the exact underlying molecular mechanism remains elusive. Lipophagy, a specialized form of selective autophagy, is crucial for the degradation of lipid droplets to maintain intracellular lipid metabolism homeostasis. In this study, arsenic treatment induced lipophagy, as evidenced by the co-localization of LC3 with lipid droplets. Remarkably, arsenic exposure increased the expression levels of Perilipin 5 (PLIN5), a lipid droplet-associated protein, both at the mRNA and protein levels. Moreover, silencing PLIN5 influenced arsenic-induced lipolysis. Consequently, the results of this study indicate that PLIN5 serves as a substrate protein involved in arsenic-induced lipophagy. This research offers a novel perspective on the mechanisms of arsenic-induced HSCs activation and liver lipid metabolism, potentially guiding new strategies for the prevention and treatment of arsenic-related liver diseases.

Prognostic assessment of early-stage liver cirrhosis induced by HCV using an integrated model of CX3CR1-associated immune infiltration genes

Chemokine (C-X3-C motif) Receptor 1 (CX3CR1) primarily mediates the chemotaxis and adhesion of immune cells. However, its role in hepatitis C virus (HCV)-induced early-stage liver cirrhosis remains unexplored. GSE15654 was downloaded from the GEO database. The Cox regression model, CIBERSORT, and LASSO technique were utilized to identify CX3CR1-associated immune infiltration genes (IIGs). Surgical resection samples were collected for verification, including 3 healthy controls (HC), 4 individuals with HCV-induced hepatic cirrhosis, and 3 with HCV-induced liver failure. High CX3CR1 expression correlated with worse prognosis in early-stage cirrhosis. CX3CR1-associated IIGs, namely ACTIN4, CD1E, TMCO1, and WSF1, were identified, showing specific expression in the livers of individuals with post-hepatic cirrhosis and liver failure compared to HC. LOC400499 and MTHFD2 were elevated in individuals with liver failure in comparison to those with hepatocirrhosis. Notably, high infiltration of plasma cells and low infiltration of monocytes were predictive of poor prognosis in early-stage cirrhosis. The combined risk model predicted that high expression of CX3CR1-associated IIGs and increased infiltration of plasma cells were associated with unfavorable prognosis in individuals with HCV-induced early-stage liver cirrhosis. The developed combined risk model effectively predicted the prognosis of these individuals.

Alleviation of liver fibrosis by inhibiting a non-canonical ATF4-regulated enhancer program in hepatic stellate cells

Liver fibrosis is a critical liver disease that can progress to more severe manifestations, such as cirrhosis, yet no effective targeted therapies are available. Here, we identify that ATF4, a master transcription factor in ER stress response, promotes liver fibrosis by facilitating a stress response-independent epigenetic program in hepatic stellate cells (HSCs). Unlike its canonical role in regulating UPR genes during ER stress, ATF4 activates epithelial-mesenchymal transition (EMT) gene transcription under fibrogenic conditions. HSC-specific depletion of ATF4 suppresses liver fibrosis in vivo. Mechanistically, TGFβ resets ATF4 to orchestrate a unique enhancer program for the transcriptional activation of pro-fibrotic EMT genes. Analysis of human data confirms a strong correlation between HSC ATF4 expression and liver fibrosis progression. Importantly, a small molecule inhibitor targeting ATF4 translation effectively mitigates liver fibrosis. Together, our findings identify a mechanism promoting liver fibrosis and reveal new opportunities for treating this otherwise non-targetable disease.

Unveiling the role of Pafah1b3 in liver fibrosis: A novel mechanism revealed

Liver fibrosis is a common outcome of various chronic hepatic insults, characterized by excessive extracellular matrix (ECM) deposition. The precise mechanisms, however, remain largely undefined. This study identified an elevated expression of platelet-activating factor acetylhydrolase 1B3 (Pafah1b3) in liver tissues from both carbon tetrachloride (CCl4)-treated mice and patients with cirrhosis. Deletion of Pafah1b3 significantly attenuated CCl4-induced fibrosis, hepatic stellate cell (HSC) activation, and activation of transforming growth factor-β (TGF-β) signaling. Mechanistically, PAFAH1B3 binds to mothers against decapentaplegic homolog 7 (SMAD7), disrupting SMAD7's interaction with TGF-β receptor 1 (TβR1), which subsequently decreases TβR1 ubiquitination and degradation. Pharmacological inhibition using 3-IN-P11, a specific Pafah1b3 inhibitor, conferred protective effects against CCl4-induced fibrosis in mice. Furthermore, Pafah1b3 deficiency reduced hepatic inflammation. Overall, these results establish a pivotal role for Pafah1b3 in modulating TGF-β signaling and driving HSC activation.

Mechanistic insight into the hepatoprotective effect of Moringa oleifera Lam leaf extract and telmisartan against carbon tetrachloride-induced liver fibrosis: plausible roles of TGF-β1/SMAD3/SMAD7 and HDAC2/NF-κB/PPARγ pathways

The increasing prevalence and limited therapeutic options for liver fibrosis necessitates more medical attention. Our study aims to investigate the potential molecular targets by which Moringa oleifera Lam leaf extract (Mor) and/or telmisartan (Telm) alleviate carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Liver fibrosis was induced in male Sprague-Dawley rats by intraperitoneal injection of 50% CCl4 (1 ml/kg) every 72 hours, for 8 weeks. Intoxicated rats with CCl4 were simultaneously orally administrated Mor (400 mg/kg/day for 8 weeks) and/or Telm (10 mg/kg/day for 8 weeks). Treatment of CCl4-intoxicated rats with Mor/Telm significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities compared to CCl4 intoxicated group (P < 0.001). Additionally, Mor/Telm treatment significantly reduced the level of hepatic inflammatory, profibrotic, and apoptotic markers including; nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), transforming growth factor-βeta1 (TGF-β1), and caspase-3. Interestingly, co-treatment of CCl4-intoxicated rats with Mor/Telm downregulated m-RNA expression of histone deacetylase 2 (HDAC2) (71.8%), and reduced protein expression of mothers against decapentaplegic homolog 3 (p-SMAD3) (70.6%) compared to untreated animals. Mor/Telm regimen also elevated p-SMAD7 protein expression as well as m-RNA expression of peroxisome proliferator-activated receptor γ (PPARγ) (3.6 and 3.1 fold, respectively p < 0.05) compared to CCl4 intoxicated group. Histopathological picture of the liver tissue intoxicated with CCl4 revealed marked improvement by Mor/Telm co-treatment. Conclusively, this study substantiated the hepatoprotective effect of Mor/Telm regimen against CCl4-induced liver fibrosis through suppression of TGF-β1/SMAD3, and HDAC2/NF-κB signaling pathways and up-regulation of SMAD7 and PPARγ expression.

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

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

Low Dose of Nickel and Benzo [a] Anthracene in Rat-Diet, Induce Apoptosis, Fibrosis, and Initiate Carcinogenesis in Liver via NF-Ƙβ Pathway

Environmental contaminants such as polycyclic aromatic hydrocarbon (PAH) and heavy metals are major contaminants of food such as fish thus serving as source of exposure to human. This study was designed to evaluate the carcinogenic risk and other risks associated with long-term consumption of environmentally relevant dose of nickel and benzo [a] anthracene in rats. Thirty-six (36) male rats weighing between 80 and 100 g were assigned into 6 groups of 6 animals each; normal, nickel-, and benzo [a] anthracene-exposed groups for 12 and 24 weeks, respectively. Micronucleus and comet analyses were done in the blood, liver, and bone marrow. Liver function, redox, and inflammatory markers (AST, ALT, GGT, SOD, GSH, MDA, protein carbonyl, protein thiol, total protein, IL-10, 1L-1β, TNF-α, TGF-β NF-Ƙβ, and 8-oxodeoxyguansine) were analysed by standard methods. Immuno-histochemical quantification of Bax, Bcl2, and Erk 1/2 as well as mRNA expression of cyclin D1 was done in liver. From the results, weight gain was observed in varying degrees throughout the exposure period. The polychromatic erythrocytes/normochromatic erythrocytes ratio > 0.2 indicates no cytotoxic effects on the bone marrow. Percentage-MnPCE in blood significantly (p < 0.05) increased throughout exposure duration. Percentage tail DNA in blood was significantly (< 0.05) increased at weeks 20 and 24 in the exposed groups and in liver at weeks 12 (16.22 ± 0.47) and 24 (17.00 ± 0.36) of nickel-exposed rats. The aspartate amino transferase (AST):alanine amino transferase (ALT) ratio indicated fatty liver disease in the benzo [a] anthracene (0.90) and acute liver injury in the nickel (> 10 times greater than the upper limits of the reference group) exposed groups during the first 12 weeks. Observation from the histological and cytological data of the liver revealed the presence of inflammation, fibrosis, and high nuclear/cytoplasmic ratio, respectively, in the nickel and benzo [a] anthracene groups. Only benzo [a] anthracene induced liver oxidative stress with significant (p < 0.05) decrease in SOD (0.64 ± 0.02) activity and increase in protein carbonyl (7.60 ± 0.80 × 10-5) and MDA (57.10 ± 6.64) concentration after 24 weeks. Benzo [a] anthracene up-regulated the cyclin D1 expression and significantly (p < 0.05) increased the levels of the cytokines. Nickel and benzo [a] anthracene significantly (p < 0.05) increased the Bax (183.45 ± 6.50 and 199.76 ± 10.04) and Erk 1/2 (108.25 ± 6.41 and 136.74 ± 4.22) levels when compared with the control (37.43 ± 22.22 and 60.37 ± 17.86), respectively. Overall result showed that the toxic effects of nickel and benzo [a] anthracene might involve fibrosis, cirrhosis, apoptosis, and inflammation of the liver. As clearly demonstrated in this study, benzo [a] anthracene after the 24 weeks of exposure stimulates carcinogenic process by suppressing the liver antioxidant capacity, altering apoptotic, cell proliferation, and differentiation pathways.