Yinchen gongying decoction mitigates CCl4-induced chronic liver injury and fibrosis in mice implicated in inhibition of the FoxO1/TGF-β1/ Smad2/3 and YAP signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Liver fibrosis (LF) is a common reversible consequence of chronic liver damage with limited therapeutic options. Yinchen Gongying decoction (YGD) composed of two homologous plants: (Artemisia capillaris Thunb, Taraxacum monochlamydeum Hand.-Mazz.), has a traditionally application as a medicinal diet for acute icteric hepatitis. However, its impact on LF and underlying mechanisms remain unclear.

AIM OF THE STUDY

This study aims to assess the impact of YGD on a carbon tetrachloride (CCl4) induced liver fibrosis and elucidate its possible mechanisms. The study seeks to establish an experimental foundation for YGD as a candidate drug for hepatic fibrosis.

MATERIALS AND METHODS

LC-MS/MS identified 11 blood-entry components in YGD, and network pharmacology predicted their involvement in the FoxO signaling pathway, insulin resistance, and PI3K-AKT signaling pathway. Using a CCl4-induced LF mouse model, YGD's protective effects were evaluated in comparison to a positive control and a normal group. The underlying mechanisms were explored through the assessments of hepatic stellate cells (HSCs) activation, fibrotic signaling, and inflammation.

RESULTS

YGD treatment significantly improved liver function, enhanced liver morphology, and reduced liver collagen deposition in CCl4-induced LF mice. Mechanistically, YGD inhibited HSC activation, elevated MMPs/TIMP1 ratios, suppressed the FoxO1/TGF-β1/Smad2/3 and YAP pathways, and exhibited anti-inflammatory and antioxidant effects. Notably, YGD improved the insulin signaling pathway.

CONCLUSION

YGD mitigates LF in mice by modulating fibrotic and inflammatory pathways, enhancing antioxidant responses, and specifically inhibiting FoxO1/TGF-β1/Smad2/3 and YAP signal pathways.

RNA-seq combined network pharmacology reveals that Fu-Gan-Wan (FGW) inhibits liver fibrosis via NF-κB/CCL2/CCR2 and lipid peroxidation via Nrf2/HMOX1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Liver fibrosis is a serious complication of liver disease characterized by excessive collagen deposition, without effective therapeutic agents in the clinic. Fu-Gan-Wan (FGW) is an empirical formula used for the clinical treatment of hepatitis and cirrhosis. It has been shown to reverse experimental liver fibrosis. However, its corresponding mechanisms remain unclear.

AIM OF THE REVIEW

This study aimed to elucidate the key pathways and target genes of FGW in attenuating liver fibrosis.

MATERIALS AND METHODS

The therapeutic effects of different doses of FGW on liver fibrosis were investigated using a 2 mL/kg 15% CCl4-induced mouse model. Then, RNA-seq combined with network pharmacology was used to analyze the key biological processes and signaling pathways underlying the anti-liver fibrosis exertion of FGW. These findings were validated in a TGF-β1-induced model of activation and proliferation of mouse hepatic stellate cell line JS-1. Finally, the key signaling pathways and molecular targets were validated using animal tissues, and the effect of FGW on tissue lipid peroxidation was additionally observed.

RESULTS

We found that 19.5 g/kg FGW significantly down-regulated CCl4-induced elevation of hepatic ALT and AST, decreased collagen deposition, and inhibited the expression of pro-fibrotic factors α-SMA, COL1α1, CTGF, TIMP-1, as well as pro-inflammatory factor TGF-β1. Additionally, FGW at doses of 62.5, 125, and 250 μg/mL dose-dependently blocked JS-1 proliferation, migration, and activation. Furthermore, RNA-seq identified the NF-κB signaling pathway as a key target molecular pathway for FGW against liver fibrosis, and network pharmacology combined with RNA-seq focused on 11 key genes. Significant changes were identified in CCL2 and HMOX1 by tissue RT-PCR, Western blot, and immunohistochemistry. We further demonstrated that FGW significantly attenuated CCl4-induced increases in p-p65, CCL2, CCR2, and HMOX1, while significantly elevating Nrf2. Finally, FGW significantly suppressed the accumulation of lipid peroxidation products MDA and 4-HNE and reconfigured the oxidation-reduction balance, including promoting the increase of antioxidants GPx, GSH, and SOD, and the decrease of peroxidation products ROS and GSSG.

CONCLUSIONS

This study demonstrated that FGW exhibits potential in mitigating CCl4-induced hepatic fibrosis, lipid peroxidation, and iron metabolism disorders in mice. This effect may be mediated through the NF-κB/CCL2/CCR2 and Nrf2/HMOX1 pathways.

Loureirin B ameliorates cholestatic liver fibrosis via AKT/mTOR/ATG7-mediated autophagy of hepatic stellate cells

AIM OF THE STUDY

Chronic cholestasis leads to liver fibrosis, which lacks effective treatment. In this study, we investigated the role and mechanisms of action of loureirin B (LB) in cholestatic liver fibrosis.

MATERIALS AND METHODS

Bile duct ligation (BDL)-induced hepatic fibrosis mice were used as in vivo models. Transforming growth factor-β1 (TGF-β1)-pretreated HSC-T6 cells were used to explore the mechanism by which LB attenuates liver fibrosis in vitro. RNA sequencing, quantitative PCR (qPCR), western blotting, immunohistochemistry and immunofluorescence were performed to detect the fibrosis markers and measure autophagy levels. Flow cytometry, cell counting kit-8 (CCK-8) assay, and 5'-ethynyl-2'-deoxyuridine (EdU) assay were conducted to detect cell proliferation and viability. GFP-RFP-LC3 adenovirus, autophagy-related protein 7 (ATG7) siRNA, and bafilomycin A1 (BafA1) were used to verify autophagic flux.

RESULTS

Our results showed that LB ameliorates liver injury, inhibits collagen deposition, and decreases the expressions of fibrosis-related markers in BDL-induced mouse livers. In vitro, we found that LB inhibited proliferation and migration, promoted apoptosis, and inhibited the activation of HSC-T6 cells pretreated with TGF-β1. RNA sequencing analysis of HSC-T6 cells showed that LB treatment predominantly targeted autophagy-related pathways. Further protein analysis indicated that LB downregulated the expression of phosphorylated AKT (p-AKT) and phosphorylated mTOR (p-mTOR), and upregulated LC3-II, p62, and ATG7 both in vivo and in vitro. Intriguingly, ATG7 inactivation reversed the antifibrotic effects of LB on HSC-T6 cells.

CONCLUSIONS

LB can improve BDL-induced liver fibrosis by inhibiting the activation and proliferation of HSCs and is expected to be a promising antifibrotic drug.

Plasticity, heterogeneity, and multifunctionality of hepatic stellate cells in liver pathophysiology

HSCs, the resident pericytes of the liver, have consistently been at the forefront of liver research due to their crucial roles in various hepatic pathological processes. Prior literature often depicted HSCs in a binary framework, categorizing them as either quiescent or activated. However, recent advances in HSC research, particularly the advent of single-cell RNA-sequencing, have revolutionized our understanding of these cells. This sophisticated technique offers an unparalleled, high-resolution insight into HSC populations, uncovering a spectrum of diversity and functional heterogeneity across various physiological states of the liver, ranging from liver development to the liver aging process. The single-cell RNA-sequencing revelations have also highlighted the intrinsic plasticity of HSCs and underscored their complex roles in a myriad of pathophysiological processes, including liver injury, repair, and carcinogenesis. This review aims to integrate and clarify these recent discoveries, focusing on how the inherent plasticity of HSCs is central to their dynamic roles both in maintaining liver homeostasis and orchestrating responses to liver injury. Future research will clarify whether findings from rodent models can be translated to human livers and guide how these insights are harnessed to develop targeted therapeutic interventions.

Transcriptomic and proteomic investigation of the ameliorative effect of total polyphenolic glycoside extract on hepatic fibrosis in Lamiophlomis rotata Kudo via the AGE/RAGE pathway

ETHNOPHARMACOLOGICAL RELEVANCE

During the regression of liver fibrosis, a decrease in hepatic stellate cells (HSCs) can occur through apoptosis or inactivation of activated HSCs (aHSCs). A new approach for antifibrotic therapy involves transforming hepatic myofibroblasts into a quiescent-like state. Lamiophlomis rotata (Benth.) Kudo (L. rotata), an orally available Tibetan herb, has traditionally been used to treat skin disease, jaundice, and rheumatism. In our previous study, we found that the total polyphenolic glycoside extract of L. rotata (TPLR) promotes apoptosis in aHSCs for the treatment of hepatic fibrosis. However, whether TPLR induces aHSCs to become inactivated HSCs (iHSCs) is unclear, and the underlying mechanism remains largely unknown.

PURPOSE

This study aimed to examine the impact of TPLR on the phenotypes of hepatic stellate cells (HSCs) during the regression of liver fibrosis and explore the potential mechanism of action.

METHODS

The effect of TPLR on the phenotypes of hepatic stellate cells (HSCs) was assessed using immunofluorescence (IF) staining, reverse transcription-polymerase chain reaction (RT-PCR), and Western blotting. Transcriptomic and proteomic methods were employed to identify the main signaling pathways involved. Based on the omics results, the likely mechanism of TPLR on the phenotypes of aHSCs was confirmed through overexpression and knockdown experiments in TGF-β1-activated LX-2 cells. Using a CCl4-induced liver fibrosis mouse model, we evaluated the anti-hepatic fibrosis effect of TPLR and explored its potential mechanism based on omics findings.

RESULTS

TPLR was found to induce the differentiation of aHSCs into iHSCs by significantly decreasing the protein expression of α-SMA and Desmin. Transcriptomic and proteomic analyses revealed that the AGE/RAGE signaling pathway plays a crucial role in the morphological transformation of HSCs following TPLR treatment. In vitro experiments using RAGE overexpression and knockdown demonstrated that the mechanism by which TPLR affects the phenotype of HSCs is closely associated with the RAGE/RAS/MAPK/NF-κB axis. In a model of liver fibrosis, TPLR obviously inhibited the generation of AGEs and alleviated liver tissue damage and fibrosis by downregulating RAGE and its downstream targets.

CONCLUSION

The AGE/RAGE axis plays a pivotal role in the transformation of activated hepatic stellate cells (aHSCs) into inactivated hepatic stellate cells (iHSCs) following TPLR treatment, indicating the potential of TPLR as a therapeutic agent for the management of liver fibrosis.

Development of a high throughput system to screen compounds that revert the activated hepatic stellate cells to a quiescent-like state

Chronic liver injury induces fibrosis that often proceeds to cirrhosis and hepatocellular carcinoma, indicating that prevention and/or resolution of fibrosis is a promising therapeutic target. Hepatic stellate cells (HSCs) are the major driver of fibrosis by expressing extracellular matrices (ECM). HSCs, in the normal liver, are quiescent and activated by liver injury to become myofibroblasts that proliferate and produce ECM. It has been shown that activated HSCs (aHSCs) become a "quiescent-like" state by removal of liver insults. Therefore, deactivation agents can be a therapeutic drug for advanced liver fibrosis. Using aHSCs prepared from human induced pluripotent stem cells, we found that aHSCs were reverted to a quiescent-like state by a combination of chemical compounds that either inhibit or activate a signaling pathway, Lanifibranor, SB431542, Dorsomorphin, retinoic acid, palmitic acid and Y27632, in vitro. Based on these results, we established a high throughput system to screen agents that induce deactivation and demonstrate that a single chemical compound can induce deactivation.

Lactate transporter MCT1 in hepatic stellate cells promotes fibrotic collagen expression in nonalcoholic steatohepatitis

Circulating lactate is a fuel source for liver metabolism but may exacerbate metabolic diseases such as nonalcoholic steatohepatitis (NASH). Indeed, haploinsufficiency of lactate transporter monocarboxylate transporter 1 (MCT1) in mice reportedly promotes resistance to hepatic steatosis and inflammation. Here, we used adeno-associated virus (AAV) vectors to deliver thyroxin binding globulin (TBG)-Cre or lecithin-retinol acyltransferase (Lrat)-Cre to MCT1fl/fl mice on a choline-deficient, high-fat NASH diet to deplete hepatocyte or stellate cell MCT1, respectively. Stellate cell MCT1KO (AAV-Lrat-Cre) attenuated liver type 1 collagen protein expression and caused a downward trend in trichrome staining. MCT1 depletion in cultured human LX2 stellate cells also diminished collagen 1 protein expression. Tetra-ethylenglycol-cholesterol (Chol)-conjugated siRNAs, which enter all hepatic cell types, and hepatocyte-selective tri-N-acetyl galactosamine (GN)-conjugated siRNAs were then used to evaluate MCT1 function in a genetically obese NASH mouse model. MCT1 silencing by Chol-siRNA decreased liver collagen 1 levels, while hepatocyte-selective MCT1 depletion by AAV-TBG-Cre or by GN-siRNA unexpectedly increased collagen 1 and total fibrosis without effect on triglyceride accumulation. These findings demonstrate that stellate cell lactate transporter MCT1 significantly contributes to liver fibrosis through increased collagen 1 protein expression in vitro and in vivo, while hepatocyte MCT1 appears not to be an attractive therapeutic target for NASH.

Ginkgolic acid inhibits the expression of SAE1 and induces ferroptosis to exert an anti-hepatic fibrosis effect

BACKGROUND

Finding a drug for early intervention in the hepatic fibrosis process has important clinical significance. Previous studies have suggested SUMOylation as a potential target for intervention in hepatic fibrosis. However, the role of SAE1, a marker of SUMOylation, in hepatic fibrosis is unknown. Additionally, whether ginkgolic acid (GA), a SUMOylation inhibitor, inhibits hepatic fibrosis by inhibiting SUMO1-activating enzyme subunit 1 (SAE1) should be further investigated.

METHODS

Liver tissues of patients with hepatic cirrhosis and a rat model of hepatic fibrosis constructed with CCl4 (400 mg/kg, twice weekly) or TAA (200 mg/kg, twice weekly) were selected, and the degree of hepatic fibrosis was then evaluated using H&E, Sirius red, and Masson's trichrome staining. After knockdown or overexpression of SAE1 in hepatic stellate cells, the expression levels of ferroptosis and hepatic fibrosis markers were measured in vitro. After intervention with a ferroptosis inhibitor, the expression levels were again measured in vivo and in vitro.

RESULTS

We first demonstrated that SAE1 increased in patients with hepatic cirrhosis. Subsequently, testing of the rat hepatic fibrosis model confirmed that GA reduced the expression of SAE1 and improved hepatic fibrosis in rats. Then, we used hepatic stellate cell lines to confirm in vitro that GA inhibited SAE1 expression and induced ferroptosis, and that overexpression of SAE1 or inhibition of ferroptosis reversed this process. Finally, we confirmed in vivo that GA induced ferroptosis and alleviated the progression of hepatic fibrosis, while inhibiting ferroptosis also reversed the progression of hepatic fibrosis in rats.

CONCLUSION

SAE1 is a potential anti-fibrotic target protein, and GA induces ferroptosis of hepatic stellate cells by targeting SAE1 to exert an anti-hepatic fibrosis effect, which lays an experimental foundation for the future clinical application of its anti-hepatic fibrosis effect.

Antler thymosin β10 reduces liver fibrosis via inhibiting TGF-β1/SMAD pathway

Hepatic stellate cell (HSC) activation is a crucial step in the development of liver fibrosis. Previous studies have shown that antler stem cells (AnSCs) inhibited HSC activation, suggesting that this may be achieved through secreting or releasing peptides. This study aimed to investigate whether AnSC-derived peptides (AnSC-P) could reduce liver fibrosis. The results showed that AnSC-P effectively reduced liver fibrosis in rats. Furthermore, we found that thymosin β10 (Tβ-10) was rich in AnSC-P, which may be the main component of AnSC-P contributing to the reduction in liver fibrosis. A further study showed that Tβ-10 reduced liver fibrosis in rats, with a reduction in HYP and MDA levels in the liver tissues, a decrease in the serum levels of ALP, ALT, AST, and TBIL and an increase in TP and ALB. Moreover, Tβ-10 decreased the expression levels of the genes related to the TGF-β/SMAD signaling pathway in vivo. In addition, Tβ-10 also inhibited TGF-β1-induced HSC activation and decreased the expression levels of the TGF-β/SMAD signaling pathway-related genes in HSCs in vitro. In conclusion, antler Tβ-10 is a potential drug candidate for the treatment of liver fibrosis, the effect of which may be achieved via inhibition of the TGFβ/SMAD signaling pathway.

Sevelamer reverses liver fibrosis by deactivation of hepatic stellate cells

Liver fibrosis is a chronic liver disease characterized by a progressive wound healing response caused by chronic liver injury. Currently, there are no approved clinical treatments for liver fibrosis. Sevelamer is used clinically to treat hyperphosphatemia and has shown potential therapeutic effects on liver diseases. However, there have been few studies evaluating the therapeutic effects of sevelamer on liver fibrosis, and the specific mechanisms are still unclear. In this study, we investigated the antifibrotic effects of sevelamer-induced low inorganic phosphate (Pi) stress in vitro and in vivo and analyzed the detailed mechanisms. We found that low Pi stress could inhibit the proliferation of activated hepatic stellate cells (HSCs) by promoting apoptosis, effectively suppressing the migration and epithelial-mesenchymal transition (EMT) of hepatic stellate cells. Additionally, low Pi stress significantly increased the antioxidant stress response. It is worth noting that low Pi stress indirectly inhibited the activation and migration of HSCs by suppressing transforming growth factor β (TGF-β) expression in macrophages. In a rat model of liver fibrosis, oral administration of sevelamer significantly decreased blood phosphorus levels, improved liver function, reduced liver inflammation, and increased the antioxidant stress response in the liver. Our study revealed that the key mechanism by which sevelamer inhibited liver fibrosis involved binding to gastrointestinal phosphate, resulting in a decrease in blood phosphorus levels, the downregulation of TGF-β expression in macrophages, and the inhibition of HSC migration and fibrosis-related protein expression. Therefore, our results suggest that sevelamer-induced low Pi stress can attenuate hepatic stellate cell activation and inhibit the progression of liver fibrosis, making it a potential option for the treatment of liver fibrosis and other refractory chronic liver diseases.

Protective hepatocyte signals restrain liver fibrosis in metabolic dysfunction-associated steatohepatitis

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects nearly 40% of the global adult population and may progress to metabolic dysfunction-associated steatohepatitis (MASH), and MASH-associated liver fibrosis and cirrhosis. Despite numerous studies unraveling the mechanism of hepatic fibrogenesis, there are still no approved antifibrotic therapies. The development of MASLD and liver fibrosis results from complex cell-cell interactions that often initiate within hepatocytes but remain incompletely understood. In this issue of the JCI, Yan and colleagues describe an ATF3/HES1/CEBPA/OPN pathway that links hepatocyte signals to fibrogenic activation of hepatic stellate cells and may provide new perspectives on therapeutic options for MASLD-induced liver fibrosis.

Neutrophil-Based Bionic Delivery System Breaks Through the Capillary Barrier of Liver Sinusoidal Endothelial Cells and Inhibits the Activation of Hepatic Stellate Cells

The capillarization of hepatic sinusoids resulting from the activation of hepatic stellate cells poses a significant challenge, impeding the effective delivery of therapeutic agents to the Disse space for liver fibrosis treatment. Therefore, overcoming these barriers and achieving efficient drug delivery to activated hepatic stellate cells (aHSCs) are pressing challenge. In this study, we developed a synergistic sequential drug delivery approach utilizing neutrophil membrane hybrid liposome@atorvastatin/amlisentan (NCM@AtAm) and vitamin A-neutrophil membrane hybrid liposome @albumin (VNCM@Bai) nanoparticles (NPs) to breach the capillary barrier for targeted HSC cell delivery. Initially, NCM@AtAm NPs were successfully directed to the site of hepatic fibrosis through neutrophil-mediated inflammatory targeting, resulting in the normalization of liver sinusoidal endothelial cells (LSECs) and restoration of fenestrations under the combined influence of At and Am. Elevated tissue levels of the p-Akt protein and endothelial nitric oxide synthase (eNOS) indicated the normalization of LSECs following treatment with At and Am. Subsequently, VNCM@Bai NPs traversed the restored LSEC fenestrations to access the Disse space, facilitating the delivery of Bai into aHSCs under vitamin A guidance. Lastly, both in vitro and in vivo results demonstrated the efficacy of Bai in inhibiting HSC cell activation by modulating the PPAR γ/TGF-β1 and STAT1/Smad7 signaling pathways, thereby effectively treating liver fibrosis. Overall, our designed synergistic sequential delivery system effectively overcomes the barrier imposed by LSECs, offering a promising therapeutic strategy for liver fibrosis treatment in clinical settings.

[Effects of M2-type macrophages and GKT137831 on oxidative stress in hepatic stellate cells]

Objective: To investigate the effects of reduced nicotinamide adenine dinucleotide phosphooxidase 4 (NOX4) inhibitors GKT137831 and M2-type macrophages on oxidative stress markers NOX4, nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in the rat hepatic stellate cell line (HSC-T6). Methods: Rat bone marrow macrophages were extracted and induced using interleukin (IL)-4 to differentiate them into M2 phenotype macrophages. HSC-T6 activation was performed with 5 μg/L transforming growth factor β1 (TGF-β1). The proliferation condition of HSC-T6 cells stimulated by the NOX4 inhibitor GKT137831 at a concentration gradient of 5 to 80 μmol/L after 48 hours was detected using the Cell Counting Kit-8 (CCK-8) assay. The optimal drug concentration was chosen and divided into an HSC co-culture group (the control group) and five experimental groups: the TGF-β1 stimulation group, the TGF-β1 +GKT137831 stimulation group, the M2-type macrophage + HSC co-culture group, the M2-type macrophage +TGF-β1 stimulation group, and the M2-type + TGF-β1 + GKT137831 stimulation group. Reactive oxygen species (ROS) production level was detected in each cell using the DCFH-DA probe method. NOX4, α-smooth muscle actin (α-SMA), Nrf2, and HO-1 levels in each group of HSC cells were detected using the qRT-PCR method and the Western blot method. The t-test was used to compare the two groups. The one-way ANOVA method was used to compare multiple groups. Results: Intracellular ROS increased significantly following TGF-β1 stimulation. ROS relative levels in each cell group were 1.03±0.11, 3.88±0.07, 2.90±0.08, 0.99±0.06, 3.30±0.05, 2.21±0.11, F = 686.1, P = 0.001, respectively. The mRNA and protein expressions of NOX4, α-SMA, Nrf2, and HO-1 were significantly increased (P < 0.05). After the addition of GKT137831, ROS, and NOX4, α-SMA mRNA and protein expression were comparatively decreased in the TGF-β1 stimulation group (P < 0.05), while mRNA and protein expressions of Nrf2 and HO-1 were increased (P < 0.05). The expression of ROS and NOX4, as well as α-SMA mRNA and protein, produced by HSC were significantly decreased in the co-culture group compared to the single culture group after TGF-β1 stimulation (P < 0.05). After the addition of GKT137831, ROS, NOX4, α-SMA mRNA, and protein expression were further reduced in the co-culture group compared with the single culture group (P < 0.05), while the mRNA and protein expression of Nrf2 and HO-1 were further increased (P < 0.05). Conclusion: NOX4 inhibitor GKT137831 can reduce RO, NOX4, and α-SMA levels while increasing Nrf2 and HO-1 levels in hepatic stellate cells. After M2-type macrophage co-culture, GKT137831 assists in lowering ROS, NOX4, and α-SMA levels while accelerating Nrf2 and HO-1 levels in hepatic stellate cells, which regulates the balance between oxidative stress and anti-oxidative stress systems, thereby antagonizing the fibrosis process.

Arbidol attenuates liver fibrosis and activation of hepatic stellate cells by blocking TGF-β1 signaling

Chronic liver diseases (CLD) impact over 800 million people globally, causing about 2 million deaths annually. Arbidol (ARB), an indole-derivative used to treat influenza virus infection, was extensively used during COVID-19 pandemic in China. In recent years, studies have shown that ARB, compared to other antiviral drugs, exhibits greater liver-protective efficacy, indicating a potential hepatoprotective effect beyond its antiviral activity. However, the mechanism remains unclear. In this study, we investigated the impact of ARB on liver injury/fibrosis in bile duct ligated (BDL) mice and its effect on spontaneous and transforming growth factor β1 (TGF-β1)-induced activation of primary cultured hepatic stellate cells (HSCs). Oral administration of ARB significantly ameliorated BDL-induced liver injury/fibrosis as reflected by decreased serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), reduced collagen deposition, and diminished mRNA expression of fibrosis markers. ARB notably inhibited spontaneous and TGF-β1-induced activation of primary cultured HSCs. Moreover, ARB also drastically attenuated mRNA expression levels of platelet-derived growth factor receptor (Pdgfr), transforming growth factor-beta receptor (Tgfbr) 1, Tgfbr2, matrix metalloproteinase (Mmp)-2, and Mmp-9 in activated HSCs. We further demonstrate that ARB mitigated Smad2/3 phosphorylation in both TGF-β1 treated HSCs and BDL mice. These data together demonstrate that the therapeutic efficacy of ARB on liver fibrosis is independent of its antiviral activity and likely is achieved by blocking TGF-β1 signaling-mediated HSC activation.

Dual-Targeting Macrophages and Hepatic Stellate Cells by Modified Albumin Nanoparticles for Liver Cirrhosis Treatment

Hepatic cirrhosis has become a global public health concern with high mortality and currently lacks effective clinical treatment methods. Activation of hepatic stellate cells (HSCs) and the large number of macrophages infiltrating into the liver play a critical role in the development of liver cirrhosis. This study developed a novel modified nanoparticle system (SRF-CS-PSA NPs) in which Sorafenib (SRF) was encapsulated by palmitic acid-modified albumin (PSA) and further modified with chondroitin sulfate (CS). These modifications enabled the SRF-CS-PSA NPs to effectively target hepatic stellate cells (HSCs) and macrophages. SRF-CS-PSA NPs showed uniform particle size distribution of approximately 120 nm and high loading efficiency of up to 99.5% and can be taken up by HSCs and macrophages via CD44 and SR-A receptors, respectively. In a mouse model of liver cirrhosis, SRF-CS-PSA NPs demonstrated superior targeting and inhibition of HSCs and macrophages, effectively reversing the process of liver cirrhosis. Overall, our study demonstrates the potential of SRF-CS-PSA NPs as a targeted therapy for liver cirrhosis, with promising clinical applications.

Melatonin ameliorates hepatic fibrosis via the melatonin receptor 2-mediated upregulation of BMAL1 and anti-oxidative enzymes

Hepatic fibrosis, when left untreated, causes serious health problems that progress to cirrhosis and, in some cases, liver cancer. Activation of hepatic stellate cells may be a key characteristic in the development of hepatic fibrosis. Melatonin, a pineal hormone, exerts anti-fibrotic effects; however, the exact mechanisms remain unclear. In this study, the beneficial effects of melatonin against hepatic fibrosis and the underlying mechanisms were investigated using the human hepatic stellate cell line, LX-2, and in vivo murine animal models. The results showed that melatonin suppressed the expression of transforming growth factor (TGF)-β1-induced fibrosis markers and production of reactive oxygen species in LX-2 cells. Either 4-phenyl-2-propionamidotetralin, a melatonin receptor 2 selective antagonist, or melatonin receptor 2 small interfering RNA abolished the suppressive effects of melatonin, suggesting the involvement of melatonin receptor 2 in melatonin-induced anti-fibrotic and anti-oxidative actions. Melatonin increased the expression of the brain and muscle aryl hydrocarbon receptor nuclear translocator-like 1 (BMAL1), a positive circadian clock gene. BMAL1 knockdown reduced the anti-fibrotic and anti-oxidative effects of melatonin, demonstrating the protective effects of melatonin against TGF-β1-induced hepatic stellate cell activation by exhibiting melatonin receptor 2-BMAL1-anti-oxidative effects. In high-fat diet-induced and carbon tetrachloride-induced hepatic fibrosis models, oral melatonin administration decreased the expression of hepatic fibrosis markers and increased the expression of messenger RNA and levels of proteins of BMAL1 and melatonin receptor 2. Thus, melatonin exerted protective effects against hepatic fibrosis through melatonin receptor 2 activation, followed by an upregulation of the BMAL1-anti-oxidative enzyme pathways.

Spinosin inhibits activated hepatic stellate cell to attenuate liver fibrosis by targeting Nur77/ASK1/p38 MAPK signaling pathway

AIM

Liver fibrosis remains a great challenge in the world. Spinosin (SPI), a natural flavonoid-C-glycoside, possesses various pharmacological activities including anti-inflammatory and anti-myocardial fibrosis effects. In this study, we investigate whether SPI can be a potential lead for the treatment of liver fibrosis and explore whether the orphan nuclear receptor Nur77, a negative regulator of liver fibrosis development, plays a critical role in SPI's action.

METHODS

A dual luciferase reporter system of α-SMA was established to evaluate the effect of SPI on hepatic stellate cell (HSC) activation in LX2 and HSC-T6 cells. A mouse model of CCl4-induced liver fibrosis was used to test the efficacy of SPI against liver fibrosis. The expression levels of Nur77, inflammatory cytokines and collagen were determined by Western blotting and qPCR. Potential kinase pathways involved were also analyzed. The affinity of Nur77 with SPI was documented by fluorescence titration.

RESULTS

SPI can strongly suppress TGF-β1-mediated activation of both LX2 and HSC-T6 cells in a dose-dependent manner. SPI increases the expression of Nur77 and reduces TGF-β1-mediated phosphorylation levels of ASK1 and p38 MAPK, which can be reversed by knocking out of Nur77. SPI strongly inhibits collagen deposition (COLA1) and reduces inflammatory cytokines (IL-6 and IL-1β), which is followed by improved liver function in the CCl4-induced mouse model. SPI can directly bind to R515 and R563 in the Nur77-LBD pocket with a Kd of 2.14 μM.

CONCLUSION

Spinosin is the major pharmacological active component of Ziziphus jujuba Mill. var. spinosa which has been frequently prescribed in traditional Chinese medicine. We demonstrate here for the first time that spinosin is a new therapeutic lead for treatment of liver fibrosis by targeting Nur77 and blocking the ASK1/p38 MAPK signaling pathway.

The m6A reader IGF2BP2 regulates glycolytic metabolism and mediates histone lactylation to enhance hepatic stellate cell activation and liver fibrosis

Evidence for the involvement of N6-Methyladenosine (m6A) modification in the etiology and progression of liver fibrosis has emerged and holds promise as a therapeutic target. Insulin-like growth factor 2 (IGF2) mRNA-binding protein 2 (IGF2BP2) is a newly identified m6A-binding protein that functions to enhance mRNA stability and translation. However, its role as an m6A-binding protein in liver fibrosis remains elusive. Here, we observed that IGF2BP2 is highly expressed in liver fibrosis and activated hepatic stellate cells (HSCs), and inhibition of IGF2BP2 protects against HSCs activation and liver fibrogenesis. Mechanistically, as an m6A-binding protein, IGF2BP2 regulates the expression of Aldolase A (ALDOA), a key target in the glycolytic metabolic pathway, which in turn regulates HSCs activation. Furthermore, we observed that active glycolytic metabolism in activated HSCs generates large amounts of lactate as a substrate for histone lactylation. Importantly, histone lactylation transforms the activation phenotype of HSCs. In conclusion, our findings reveal the essential role of IGF2BP2 in liver fibrosis by regulating glycolytic metabolism and highlight the potential of targeting IGF2BP2 as a therapeutic for liver fibrosis.

LncRNA-SNHG5 mediates activation of hepatic stellate cells by regulating NF2 and Hippo pathway

Long noncoding RNA small nucleolar RNA host gene 5 (SNHG5) is an oncogene found in various human cancers. However, it is unclear what role SNHG5 plays in activating hepatic stellate cells (HSCs) and liver fibrosis. In this study, SNHG5 was found to be upregulated in activated HSCs in vitro and in primary HSCs isolated from fibrotic liver in vivo, and inhibition of SNHG5 suppressed HSC activation. Notably, Neurofibromin 2 (NF2), the main activator for Hippo signalling, was involved in the effects of SNHG5 on HSC activation. The interaction between SNHG5 and NF2 protein was further confirmed, and preventing the combination of the two could effectively block the effects of SNHG5 inhibition on EMT process and Hippo signaling. Additionally, higher SNHG5 was found in chronic hepatitis B patients and associated with the fibrosis stage. Altogether, we demonstrate that SNHG5 could serve as an activated HSCs regulator via regulating NF2 and Hippo pathway.

Predictive toxicological effects of Artemisia absinthium essential oil on hepatic stellate cells

Medicinal plants are important worldwide, considering their properties for treating diseases; however, few studies have evaluated their toxicological potential. Among them, Artemisia absinthium is frequently used to treat liver diseases, because its essential oil has several popular therapeutic properties. Based on this information, in the present study, we investigated molecular connectors of physiological effects of the Artemisia absinthium essential oil on human hepatic stellate cell line, LX-2, to explore the potential toxicity of the plant on liver cells. LX-2 is a cellular model to investigate mechanisms of liver fibrosis; then, to analyze the essential oil effects LX-2 was cultured under different conditions, treated or not with the essential oil at 0.4 μg/μL for 24 h. Next, fluorescence microscopy analyses, gene expression measurements, and biochemical approaches revealed that the essential oil reduced pro-fibrogenic markers; however, disrupt lipid metabolism, and cause cellular stress, by the activation of cellular detoxification and pro-inflammatory processes. In conclusion, the hepatic stellate cells incubated with the essential oil present an antifibrotic potential, supporting its popular use; however, the combined results suggest that the essential oil of Artemisia absinthium should be used with caution.

Water extract of earthworms mitigates mouse liver fibrosis by potentiating hepatic LKB1/Nrf2 axis to inhibit HSC activation and hepatocyte death

ETHNOPHARMACOLOGICAL RELEVANCE

When left untreated, liver fibrosis (LF) causes various chronic liver diseases. Earthworms (Pheretima aspergillum) are widely used in traditional medicine because of their capacity to relieve hepatic diseases.

AIM OF THE STUDY

This study aimed to explore the anti-LF effects of water extract of earthworms (WEE) and the underlying molecular mechanisms.

MATERIALS AND METHODS

A CCl4-induced mouse model of LF was used to study the impact of WEE on LF in vivo. The anti-LF activity of WEE in mice was compared with that of silybin, which can be clinically applied in LF intervention and was used as a positive control. Activation of LX-2 hepatic stellate cells (HSCs) and apoptosis and ferroptosis of AML-12 hepatocytes induced by TGFβ1 were used as in vitro models.

RESULTS

WEE drastically improved LF in mice. WEE reduced markers of activated HSCs in mice and inhibited TGFβ1-induced activation of LX-2 HSCs in vitro. Additionally, WEE suppressed CCl4-induced apoptosis and ferroptosis in mouse hepatocytes. Mechanistically, WEE induced Nrf2 to enter the nuclei of the mouse liver cells, and the hepatic levels of Nrf2-downstream antioxidative factors increased. LKB1/AMPK/GSK3β is an upstream regulatory cascade of Nrf2. In the LF mouse model, WEE increased hepatic phosphorylated LKB1, AMPK, and GSK3β levels. Similar results were obtained for the LX-2 cells. In AML-12 hepatocytes and LX-2 HSCs, WEE elevated intracellular Nrf2 levels, promoted its nuclear translocation, and inhibited TGFβ1-induced ROS accumulation. Knocking down LKB1 abolished the impact of WEE on the AMPK/GSK3β/Nrf2 cascade and eliminated its protective effects against TGFβ1.

CONCLUSIONS

Our findings reveal that WEE improves mouse LF triggered by CCl4 and supports its application as a promising hepatoprotective agent against LF. The potentiation of the hepatic antioxidative AMPK/GSK3β/Nrf2 cascade by activating LKB1 and the subsequent suppression of HSC activation and hepatocyte apoptosis and ferroptosis are implicated in WEE-mediated alleviation of LF.

Jiawei Taohe Chengqi decoction inhibition of the notch signal pathway affects macrophage reprogramming to inhibit HSCs activation for the treatment of hepatic fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

Jiawei Taohe Chengqi Tang (JTCD) is a modified formulation of Traditional Chinese Medicine (TCM) known as Taohe Chengqi Decoction, which has been described in the ancient TCM literature "Treatise on Febrile Diseases". As a formula that can activate blood circulation and eliminate blood stasis and regulate Yin and Yang in traditional Chinese medicine applications, JTCD has been reported to be effective in the treatment of chronic liver disease and hepatic fibrosis (HF).

AIM OF STUDY

The current study aimed to evaluate the effectiveness of JTCD in modulating hepatic macrophages by regulating the Notch signal pathway, and to further investigate the mechanisms underlying macrophage reprogramming that leads to HF.

MATERIALS AND METHODS

Molecular assays were performed using in vitro cultures of human mononuclear THP-1 cells and human-derived hepatic stellate cells LX-2. CCl4-induced mice were utilized as an in vivo model to simulate HF.

RESULTS

Our results demonstrated that JTCD exhibited dual effects by inhibiting hepatic stellate cell (HSCs) activation and modulating the polarisation of macrophages towards the M2 phenotype while decreasing the M1 phenotype. Network pharmacological analyses and molecular docking studies revealed that the Notch signal pathway was significantly enriched and played a crucial role in the therapeutic response of JTCD against HF. Moreover, through the establishment of a co-culture model, we validated that JTCD inhibited the Notch signal pathway in macrophages, leading to alterations in macrophage reprogramming, subsequent inhibition of HSC activation, and ultimately exerting anti-HF effects.

CONCLUSION

In conclusion, our findings provide solid evidence for JTCD in treating HF, as it suppresses the Notch signal pathway in macrophages, regulates macrophage reprogramming, and inhibits HSC activation.

Angelica dahurica extract and its effective component bergapten alleviated hepatic fibrosis by activating FXR signaling pathway

Angelica dahurica (A. dahurica) has a wide range of pharmacological effects, including analgesic, anti-inflammatory and hepatoprotective effects. In this study, we investigated the effect of A. dahurica extract (AD) and its effective component bergapten (BG) on hepatic fibrosis and potential mechanisms. Hepatic fibrosis was induced by intraperitoneal injection with carbon tetrachloride (CCl4) for 1 week, and mice were administrated with AD or BG by gavage for 1 week before CCl4 injection. Hepatic stellate cells (HSCs) were stimulated by transforming growth factor-β (TGF-β) and cultured with AD, BG, GW4064 (FXR agonist) or Guggulsterone (FXR inhibitor). In CCl4-induced mice, AD significantly decreased serum aminotransferase, reduced excess accumulation of extracellular matrix (ECM), inhibited caspase-1 and IL-1β, and increased FXR expressions. In activated HSCs, AD suppressed the expressions of α-SMA, collagen I, and TIMP-1/MMP-13 ratio and inflammatory factors, functioning as FXR agonist. In CCl4-induced mice, BG significantly improved serum transaminase and histopathological changes, reduced ECM excessive deposition, inflammatory response, and activated FXR expression. BG increased FXR expression and inhibited α-SMA and IL-1β expressions in activated HSCs, functioning as GW4064. FXR deficiency significantly attenuated the decreasing effect of BG on α-SMA and IL-1β expressions in LX-2 cells. In conclusion, AD could regulate hepatic fibrosis by regulating ECM excessive deposition and inflammation. Activating FXR signaling by BG might be the potential mechanism of AD against hepatic fibrosis.

LncRNA SNHG11 reprograms glutaminolysis in hepatic stellate cells via Wnt/β-catenin/GLS axis

Long non-coding RNAs (lncRNAs) have been identified as decisive regulators of liver fibrosis. Hepatic stellate cells (HSCs), major hepatic cells contributing to liver fibrosis, undergo metabolic reprogramming for transdifferentiation and activation maintenance. As a crucial part of metabolic reprogramming, glutaminolysis fuels the tricyclic acid (TCA) cycle that renders HSCs addicted to glutamine. However, how lncRNAs reprogram glutamine metabolism in HSCs is unknown. For this research, we characterized the pro-fibrogenic function of small nucleolar host gene 11 (SNHG11). Our data showed that in carbon tetrachloride (CCl4, 7 μL/g, intraperitoneally) treated C57BL/6J mice, SNHG11 expression was highly up-regulated in fibrotic livers and activated primary HSCs. SNHG11 knockdown attenuated the accumulation of fibrotic markers α-SMA and Col1A1 in liver fibrosis tissues and activated HSCs. Western blot and qRT-PCR assays demonstrated that glutaminase (GLS), the rate-limiting enzyme for glutaminolysis, was a downstream target of SNHG11. Furthermore, SNHG11 upregulated glutaminolysis in HSCs through the activation of the Wnt/β-catenin signaling pathway. The results highlighted that SNHG11 is a glutaminolysis-regulated lncRNA that promotes liver fibrosis. A novel insight into the metabolic mechanism that reprograms glutaminolysis in HSCs could be exploited as anti-fibrotic targets.

GATA3 promotes the autophagy and activation of hepatic stellate cell in hepatic fibrosis via regulating miR-370/HMGB1 pathway

BACKGROUND

Hepatic fibrosis (HF) is a common result of the repair process of various chronic liver diseases. Hepatic stellate cells (HSCs) activation is the central link in the occurrence of HF.

METHODS

ELISA and histological analysis were performed to detect the pathological changes of liver tissues. In vitro, HSCs were treated with TGF-β1 as HF cell model. Combination of GATA-binding protein 3 (GATA3) and miR-370 gene promoter was ensured by ChIP and luciferase reporter assay. Autophagy was monitored by observing the GFP-LC3 puncta formation. The interaction between miR-370 and high mobility group box 1 protein (HMGB1) was verified by luciferase reporter assay.

RESULTS

CCl4-induced HF mice exhibited an increase of ALT and AST, and severe damage and fibrosis of liver tissues. GATA3 and HMGB1 were up-regulated, and miR-370 was down-regulated in CCl4-induced HF mice and activated HSCs. GATA3 enhanced expression of the autophagy-related proteins and activation markers in the activated HSCs. Inhibition of autophagy partly reversed GATA3-induced activation of HSCs and the promotion of GATA3 to hepatic fibrosis. Moreover, GATA3 suppressed miR-370 expression via binding with its promotor, and enhanced HMGB1 expression in HSCs. Increasing of miR-370 inhibited HMGB1 expression by directly targeting its mRNA 3'-UTR. The promotion of GATA3 to TGF-β1-induced HSCs autophagy and activation was abrogated by miR-370 up-regulation or HMGB1 knockdown.

CONCLUSIONS

This work demonstrates that GATA3 promotes autophagy and activation of HSCs by regulating miR-370/HMGB1 signaling pathway, which contributes to accelerate HF. Thus, this work suggests that GATA3 may be a potential target for prevention and treatment of HF.

KIF18A inactivates hepatic stellate cells and alleviates liver fibrosis through the TTC3/Akt/mTOR pathway

Activation of hepatic stellate cells (HSCs) has been demonstrated to play a pivotal role in the process of liver fibrogenesis. In this study, we observed a decrease in the expression of KIF18A in fibrotic liver tissues compared to healthy liver tissues, which exhibited a negative correlation with the activation of HSCs. To elucidate the molecular mechanisms underlying the involvement of KIF18A, we performed in vitro proliferation experiments and established a CCl4-induced liver fibrosis model. Our results revealed that KIF18A knockdown enhanced HSCs proliferation and reduced HSCs apoptosis in vitro. Mouse liver fibrosis grade was evaluated with Masson's trichrome and alpha-smooth muscle actin (α-SMA) staining. In addition, the expression of fibrosis markers Col1A1, Stat1, and Timp1 were detected. Animal experiments demonstrated that knockdown of KIF18A could promote liver fibrosis, whereas overexpression of KIF18A alleviated liver fibrosis in a CCl4-induced mouse model. Mechanistically, we found that KIF18A suppressed the AKT/mTOR pathway and exhibited direct binding to TTC3. Moreover, TTC3 was found to interact with p-AKT and could promote its ubiquitination and degradation. Our findings provide compelling evidence that KIF18A enhances the protein binding between TTC3 and p-AKT, promoting TTC3-mediated ubiquitination and degradation of p-AKT. These results refine the current understanding of the mechanisms underlying the pathogenesis of liver fibrosis and may offer new targets for treating this patient population.

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

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

The inhibition of YAP Signaling Prevents Chronic Biliary Fibrosis in the Abcb4-/- Model by Modulation of Hepatic Stellate Cell and Bile Duct Epithelium Cell Pathophysiology

Primary sclerosing cholangitis (PSC) represents a chronic liver disease characterized by poor prognosis and lacking causal treatment options. Yes-associated protein (YAP) functions as a critical mediator of fibrogenesis; however, its therapeutic potential in chronic biliary diseases such as PSC remains unestablished. The objective of this study is to elucidate the possible significance of YAP inhibition in biliary fibrosis by examining the pathophysiology of hepatic stellate cells (HSC) and biliary epithelial cells (BEC). Human liver tissue samples from PSC patients were analyzed to assess the expression of YAP/connective tissue growth factor (CTGF) relative to non-fibrotic control samples. The pathophysiological relevance of YAP/CTGF in HSC and BEC was investigated in primary human HSC (phHSC), LX-2, H69, and TFK-1 cell lines through siRNA or pharmacological inhibition utilizing verteporfin (VP) and metformin (MF). The Abcb4-/- mouse model was employed to evaluate the protective effects of pharmacological YAP inhibition. Hanging droplet and 3D matrigel culture techniques were utilized to investigate YAP expression and activation status of phHSC under various physical conditions. YAP/CTGF upregulation was observed in PSC patients. Silencing YAP/CTGF led to inhibition of phHSC activation and reduced contractility of LX-2 cells, as well as suppression of epithelial-mesenchymal transition (EMT) in H69 cells and proliferation of TFK-1 cells. Pharmacological inhibition of YAP mitigated chronic liver fibrosis in vivo and diminished ductular reaction and EMT. YAP expression in phHSC was effectively modulated by altering extracellular stiffness, highlighting YAP's role as a mechanotransducer. In conclusion, YAP regulates the activation of HSC and EMT in BEC, thereby functioning as a checkpoint of fibrogenesis in chronic cholestasis. Both VP and MF demonstrate effectiveness as YAP inhibitors, capable of inhibiting biliary fibrosis. These findings suggest that VP and MF warrant further investigation as potential therapeutic options for the treatment of PSC.

Ginsenoside Rg3 promotes hepatic stellate cell ferroptosis by epigenetically regulating ACSL4 to suppress liver fibrosis progression

BACKGROUND

Ginsenoside Rg3 (G-Rg3), extracted from Panax notoginseng, possesses hepatoprotective properties. Hepatic stellate cells (HSCs) activation is responsible for liver fibrosis. Recent studies have reported the suppressive effects of G-Rg3 on HSC activation and proliferation. Ferroptosis is a novel iron regulated cell death. ACSL4, a key indicator of ferroptosis, is commonly methylated in various diseases.

PURPOSE

However, the role of ACSL4 methylation-mediated HSC ferroptosis in G-Rg3 inhibition of hepatic fibrosis needs to be explored.

METHODS

Effects of G-Rg3 on inhibiting fibrosis were evaluated in vivo and in vitro. The impact of G-Rg3 on HSC ferroptosis was assessed in vitro. Furthermore, the expression of ACSL4, ACSL4 methylation and microRNA-6945-3p (miR-6945-3p) levels were determined.

RESULTS

G-Rg3 significantly alleviated CCl4-induced liver fibrosis, accompanied by collagen downregulation. In vitro, G-Rg3 contributed to HSC inactivation, leading to decreased collagen production. G-Rg3 induced HSC ferroptosis, characterized by increased iron accumulation, depletion of glutathione, malondialdehyde levels, and generation of lipid reactive oxygen species. Moreover, G-Rg3 promoted ACSL4 demethylation and restored its expression. Notably, DNMT3B counteracted the effect of G-Rg3-mediated inhibition of ACSL4 methylation and was targeted by miR-6945-3p. Further investigations revealed that G-Rg3 suppressed ACSL4 methylation through miR-6945-3p-mediated DNMT3B inhibition. Consistent with this, miR-6945-3p inhibition reversed G-Rg3-induced ACSL4 expression and HSC ferroptosis.

CONCLUSION

G-Rg3 inhibits ACSL4 methylation by miR-6945-3p-mediated DNMT3B inhibition, thereby promoting HSC ferroptosis and mitigating liver fibrosis.

Identification of (E)-1-((1H-indol-3-yl)methylene)-4-substitute-thiosemicarbazones as potential anti-hepatic fibrosis agents

Liver fibrosis remains a global health challenge due to its rapidly rising prevalence and limited treatment options. The orphan nuclear receptor Nur77 has been implicated in regulation of autophagy and liver fibrosis. Targeting Nur77-mediated autophagic flux may thus be a new promising strategy against hepatic fibrosis. In this study, we synthesized four types of Nur77-based thiourea derivatives to determine their anti-hepatic fibrosis activity. Among the synthesized thiourea derivatives, 9e was the most potent inhibitor of hepatic stellate cells (HSCs) proliferation and activation. This compound could directly bind to Nur77 and inhibit TGF-β1-induced α-SMA and COLA1 expression in a Nur77-dependent manner. In vivo, 9e significantly reduced CCl4-mediated hepatic inflammation response and extracellular matrix (ECM) production, revealing that 9e is capable of blocking the progression of hepatic fibrosis. Mechanistically, 9e induced Nur77 expression and enhanced autophagic flux by inhibiting the mTORC1 signaling pathway in vitro and in vivo. Thus, the Nur77-targeted lead 9e may serve as a promising candidate for treatment of chronic liver fibrosis.

Hepatocyte GPCR signaling regulates IRF3 to control hepatic stellate cell transdifferentiation

BACKGROUND

Interferon Regulatory Factor 3 (IRF3) is a transcription factor that plays a crucial role in the innate immune response by recognizing and responding to foreign antigens. Recently, its roles in sterile conditions are being studied, as in metabolic and fibrotic diseases. However, the search on the upstream regulator for efficient pharmacological targeting is yet to be fully explored. Here, we show that G protein-coupled receptors (GPCRs) can regulate IRF3 phosphorylation through of GPCR-Gα protein interaction.

RESULTS

IRF3 and target genes were strongly associated with fibrosis markers in liver fibrosis patients and models. Conditioned media from MIHA hepatocytes overexpressing IRF3 induced fibrogenic activation of LX-2 hepatic stellate cells (HSCs). In an overexpression library screening using active mutant Gα subunits and Phos-tag immunoblotting, Gαs was found out to strongly phosphorylate IRF3. Stimulation of Gαs by glucagon or epinephrine or by Gαs-specific designed GPCR phosphorylated IRF3. Protein kinase A (PKA) signaling was primarily responsible for IRF3 phosphorylation and Interleukin 33 (IL-33) expression downstream of Gαs. PKA phosphorylated IRF3 on a previously unrecognized residue and did not require reported upstream kinases such as TANK-binding kinase 1 (TBK1). Activation of Gαs signaling by glucagon induced IL-33 production in hepatocytes. Conditioned media from the hepatocytes activated HSCs, as indicated by α-SMA and COL1A1 expression, and this was reversed by pre-treatment of the media with IL-33 neutralizing antibody.

CONCLUSIONS

Gαs-coupled GPCR signaling increases IRF3 phosphorylation through cAMP-mediated activation of PKA. This leads to an increase of IL-33 expression, which further contributes to HSC activation. Our findings that hepatocyte GPCR signaling regulates IRF3 to control hepatic stellate cell transdifferentiation provides an insight for understanding the complex intercellular communication during liver fibrosis progression and suggests therapeutic opportunities for the disease. Video Abstract.

The combination of tetracyclines effectively ameliorates liver fibrosis via inhibition of EphB1/2

Eph receptor tyrosine kinase EphB1/2 contributes to the development of liver fibrosis, suggesting the rationale that EphB1/2 inhibitors may be effective in liver fibrosis therapy. Since tetracycline antibiotics were recently demonstrated as EphB kinase inhibitors, in present study we investigated their therapeutic potential against liver fibrosis. Our results showed that the tetracycline combination of demeclocycline (D), chlortetracycline (C), and minocycline (M) inhibited the activation of hepatic stellate cells (HSCs) in vitro and alleviated CCl4-induced animal model of liver fibrosis in vivo. Mechanistically, DCM combination inhibited EphB1/2 phosphorylation and subsequent activation of the MAPK signaling. Moreover, we found that short-term and low-dose DCM combination treatment decreased tissue inflammation and improved liver fibrosis in mice. Thus, our study indicates that tetracyclines may be repurposed for the treatment of liver fibrosis.

Sesamol as a potential candidate for the treatment of hepatic fibrosis, based on its regulation of FXR/LXR axis-mediated inhibition of autophagy through crosstalk between hepatic cells and macrophage

BACKGROUND

Sesamol (SEM), a natural lignan compound isolated from sesame, has strong anti-oxidant property, regulating lipid metabolism, decreasing cholesterol and hepatoprotection. However, its anti-hepatic fibrosis effect and mechanisms have not been comprehensively elucidated.

HYPOTHESIS/PURPOSE

This study aims to investigate the anti-hepatic fibrosis of SEM and its underlying mechanisms.

METHOD

C57BL/6 mice with hepatic fibrosis were induced by TAA, then administrated with SEM or curcumin, respectively. HSCs were stimulated by TGF-β or conditioned medium, and then cultured with SEM, GW4064, GW3965, Rapamycin (RA) or 3-methyladenine (3-MA), respectively. Mice with hepatic fibrosis also were administrated with SEM, RA or 3-MA to estimate the effect of SEM on autophagy.

RESULTS

In vitro, SEM significantly inhibited extracellular matrix deposition, P2 × 7r-NLRP3, and inflammatory cytokines. SEM increased FXR and LXRα/β expressions and decreased MAPLC3α/β and P62 expressions, functioning as 3-MA (autophagy inhibitor). In vivo, SEM reduced serum transaminase, histopathology changes, fibrogenesis, autophagy markers and inflammatory cytokines caused by TAA. LX-2 were activated with conditioned medium from LPS-primed THP-1, which resulted in significant enhance of autophagy markers and inflammatory cytokines and decrease of FXR and LXRα/β expressions. SEM could reverse above these changes and function as 3-MA, GW4064, or GW3965. Deficiency of FXR or LXR attenuated the regulation of SEM on α-SMA, MAPLC3α/β, P62 and IL-1β in activated LX-2. In activated THP-1, deficiency of FXR could decrease the expression of LXR, and vice versa. Deficiency of FXR or LXR in activated MΦ decreased the expressions of FXR and LXR in activated LX-2. Deficiency FXR or LXR in activated MΦ also attenuated the regulation of SEM on α-SMA, MAPLC3α/β, P62, caspase-1 and IL-1β. In vivo, SEM significantly reversed hepatic fibrosis via FXR/LXR and autophagy.

CONCLUSION

SEM could regulate hepatic fibrosis by inhibiting fibrogenesis, autophagy and inflammation. FXR/LXR axis-mediated inhibition of autophagy contributed to the regulation of SEM against hepatic fibrosis, especially based on involving in the crosstalk of HSCs-macrophage. SEM might be a prospective therapeutic candidate, and its mechanism would be a new direction or strategy for hepatic fibrosis treatment.

CD73 Blockade Alleviated Hepatic Fibrosis via Inhibiting Hepatic Stellate Cells Proliferation and Activation

BACKGROUND

Liver fibrosis is associated with the activation of hepatic stellate cells (HSCs). Inhibition of HSCs activation is a strategy for alleviating hepatic fibrogenesis. CD73 is involved in liver disease development, while the mechanism remains unclear.

OBJECTIVE

This study aimed to investigate the effect of CD73 targeting inhibition on liver fibrosis.

METHODS

Intraperitoneal injection of CCl4 was used to induce liver fibrosis in mice models. Adenosine 5'-(α, β-methylene) diphosphate sodium salt (APCP) was used for CD73 blockade. The siRNA was used to induce CD73 knockdown in HSCs. LX2 and HSC-T6 were used to investigate the role of CD73 in HSCs activation in vitro.

RESULTS

The results showed that APCP treatment could alleviate hepatic fibrosis. In fibrotic liver tissues, CD73 exhibited a positive correlation with markers of HSCs activation. Furthermore, APCP treatment and CD73 knockdown could inhibit HSCs (LX2 and HSC-T6) activation and proliferation. By using RNA sequencing of liver tissues from control, CCl4-mice, and APCP-treated mice, 851 genes that were significantly changed in CCl4 mice (vs. control) were reversed by APCP treatment. These genes were mainly enriched in cell division-associated biological processes. Moreover, we found that CD73 might be associated with autophagy in HSCs. In fibrotic liver tissues and HSCs, ATG5 and Beclin1 expression could be downregulated by CD73 knockdown and APCP treatment.

CONCLUSION

This study demonstrated the effects and mechanism of CD73 in HSCs activation and proliferation, which presents the therapeutical potential of CD73 blockage for liver fibrosis.

Yohimbine ameliorates liver inflammation and fibrosis by regulating oxidative stress and Wnt/β-catenin pathway

BACKGROUND AND PURPOSE

Chronic liver injury, caused by various aetiologies, causes recurrent tissue damage, culminating in decreased liver regenerative ability and resulting in fibrosis followed by cirrhosis. In this study, the anti-fibrotic activity of Yohimbine hydrochloride (YHC) was investigated using various in vitro models and in vivo models.

METHODS

To assess the anti-inflammatory, antioxidant, and anti-fibrotic effects of YHC, lipopolysaccharide or TGF-β induced differentiation or lipid-induced oxidative-stress models were employed using HLECs, HSC-LX2, and HepG2 cells. Further, thioacetamide (TAA) induced hepatic inflammation/fibrosis models were utilized to validate the YHC's anti-fibrotic activity in rats.

RESULTS

Inflammation/differentiation experiments in HLECs and HSC-LX2 revealed that YHC treatment significantly (p < 0.001) mitigated the lipopolysaccharide or TGF-β induced upregulation of inflammatory and fibrotic markers expression respectively. In addition, YHC dose-dependently reduced the TGF-β induced migration and palmitic acid-induced oxidative stress in HepG2 cells. Further, TAA administration (5 weeks) in vivo rat model showed increased inflammatory marker levels/expression, oxidative stress, and pathological abnormalities. Additionally, TAA administration (9 weeks) elevated the fibrotic marker expression, collagen deposition in liver tissues, and shortened longevity in rats. Treatment with YHC dose-dependently mitigated the TAA-induced abnormalities in both inflammation and fibrosis models and improved the survival of the rats. Further mechanistic approaches revealed that TAA administration elevated the JNK, Wnt components and β-catenin expression in hepatic stellate cells and animal tissues. Further treatment with YHC significantly modulated the JNK/Wnt/β-catenin signaling. Moreover, the β-catenin nuclear translocation results showed that β-catenin levels were significantly elevated in the nuclear fraction of TAA control samples and reduced in YHC-treated samples.

CONCLUSION

Yohimbine treatment significantly improved inflammation and fibrosis by inhibiting differentiation, oxidative stress, and collagen deposition by partly modulating the JNK/Wnt/β-catenin pathway. These results might serve as a foundation for proposing yohimbine as a potential lead compound for liver fibrosis.

Aloin Attenuates Oxidative Stress, Inflammation, and CCl4-Induced Liver Fibrosis in Mice: Possible Role of TGF-β/Smad Signaling

Liver fibrosis refers to the excessive buildup of extracellular matrix (ECM) components in liver tissue. It is considered a pathological response to liver damage for which there is no effective treatment. Aloin, an anthraquinone compound isolated from the aloe plant, has shown good pharmacological effects in the treatment of gastric cancer, ulcerative colitis, myocardial hypertrophy, traumatic brain injury, and other diseases; however, its specific impact on liver fibrosis remains unclear. To address this gap, we conducted a study to explore the mechanisms underlying the potential antifibrotic effect of aloin. We constructed a mouse liver fibrosis model using carbon tetrachloride (CCl4) dissolved in olive oil as a modeling drug. Additionally, a cellular model was developed by using transforming growth factor β1 (TGF-β1) as a stimulus applied to hepatic stellate cells. After aloin intervention, serum alanine aminotransferase, hepatic hydroxyproline, and serum aspartate aminotransferase were reduced in mice after aloin intervention compared to CCl4-mediated liver injury without aloin intervention. Aloin relieved the oxidative stress caused by CCl4 via reducing hepatic malondialdehyde in liver tissue and increasing the level of superoxide dismutase. Aloin treatment decreased interleukin (IL)-1β, IL-6, and tumor necrosis factor-α and increased the expression of IL-10, which inhibited the inflammatory response in liver injury. In addition, aloin inhibited the activation of hepatic stellate cells and reduced the level of α-smooth muscle actin (α-SMA) and collagen type I. In cell and animal experiments, aloin attenuated liver fibrosis, acting through the TGF-β/Smad2/3 signaling pathway, and mitigated CCl4- and TGF-β1-induced inflammation. Thus, the findings of this study provided theoretical data support and a new possible treatment strategy for liver fibrosis.

Kaempferol attenuates carbon tetrachloride (CCl4)-induced hepatic fibrosis by promoting ASIC1a degradation and suppression of the ASIC1a-mediated ERS

BACKGROUND

Kaempferol is a flavonoid derived from the herb, Kaempferia galanga L., in addition to exhibiting a wide range of pharmacological properties, kaempferol is also an anti-inflammatory, anti-lipid metabolizing, and anti-oxidative stress agent. The underlying molecular mechanisms of its effects on vascular endothelial growth factor (VEGF) secretion and activation of hepatic stellate cells (HSCs) are yet unknown. Activated HSCs induces VEGF release and extracellular matrix (ECM) accumulation which are important factors in hepatic fibrosis.

PURPOSE

Our aim is to explore how kaempferol may affect hepatic fibrosis and the mechanisms behind its effects.

METHODS

The in vivo model was Sprague-Dawley rats induced with carbon tetrachloride (CCl4). Histological staining was used to observe histological features of the liver. The levels of (alanine aminotransferase) ALT and (aspartate aminotransferase) AST were detected by the corresponding kits. Platelet-derived growth factor (PDGF) was used to stimulate the HSC-T6 rat hepatic stellate cells. The mechanisms underlying this process were investigated using a variety of molecular approaches, including immunofluorescence, RT-qPCR, and western blotting. Moreover, intracellular Ca2+ were observed by laser confocal microscope.

RESULTS

It was found that kaempferol significantly reduced the expression of ASIC1a, VEGF, α-SMA and Collagen-I proteins in a model of CCl4-induced hepatic fibrosis in rats. In HSC-T6, kaempferol inhibits activation of HSCs by decreasing expression of ASIC1a, eIF2α, p-eIF2α and ATF-4. Laser confocal fluorescence showed that kaempferol inhibited Ca2+ influx and reduced Ca2+ concentration around the endoplasmic reticulum. Molecular docking and cellular thermal shift assay (CETSA) results further indicated that kaempferol interacted with ASIC1a. We found that kaempferol may promote the degradation of ASIC1a and inhibited ASIC1a- mediated upregulation of ERS.

CONCLUSION

The data from our in vivo experiments demonstrate that kaempferol effectively attenuates hepatic fibrosis. In vitro studies we further propose a novel mechanism of kaempferol against hepatic fibrosis which can interact with ASIC1a and promote ASIC1a degradation while inhibiting the activation and VEGF release of HSCs by suppressing the ASIC1a-eIF2α-ATF-4 signaling pathway.

Bromodomain protein 4 is a key molecular driver of TGFβ1-induced hepatic stellate cell activation

Liver fibrosis is characterized by the excessive deposition of extracellular matrix in liver. Chronic liver injury induces the activation of hepatic stellate cell (HSCs), a key step in liver fibrogenesis. The activated HSC is the primary source of ECM and contributes significantly to liver fibrosis. TGFβ1 is the most potent pro-fibrotic cytokine. Bromodomain protein 4 (BrD4), an epigenetic reader of histone acetylation marks, was crucial for profibrotic gene expression in HSCs. The present study aimed to investigate the roles of BRD4 in TGFβ1-dependent HSC activation and liver fibrosis, focusing on TGFβ1-induced alterations of the levels of the fibrotic-related important proteins in HSCs by employing the heterozygous TGFβ1 knockout mice and BrD4 knockdown in vivo and in vitro. Results revealed that BrD4 protein level was significantly upregulated by TGFβ1 and BrD4 knockdown reduced TGFβ1-induced HSC activation and liver fibrosis. BrD4 was required for the influences of TGFβ1 on PDGFβ receptor and on the pathways of Smad3, Stat3, and Akt. BrD4 also mediated TGFβ1-induced increases in histone acetyltransferase p300, the pivotal pro-inflammatory NFkB p65, and tissue inhibitor of metalloproteinase 1 whereas BrD4 reduced Caspase-3 protein levels in HSCs during liver injury, independent of TGFβ1. Further experiments indicated the interaction between TGFβ1-induced BrD4 and NFkB p65 in HSCs and in liver of TAA-induced liver injury. Human cirrhotic livers were demonstrated a parallel increase in the protein levels of BrD4 and NFkB p65 in HSCs. This study revealed that BrD4 was a key molecular driver of TGFβ1-induced HSC activation and liver fibrosis.

Hepatic stellate cells activate and avoid death under necroptosis stimuli: Hepatic fibrosis during necroptosis

BACKGROUND AND AIM

Necroptosis is an emerging cell death pathway that allows cells to undergo "cellular suicide" in a caspase-independent manner. We investigated the fate of hepatic stellate cells (HSCs) under necroptotic stimuli.

METHODS AND RESULTS

The RNA level of mixed lineage kinase domain-like protein (MLKL) is higher in patients with non-alcoholic fatty liver disease than in healthy controls. Hepatic fibrosis was significantly lower in MLKL-KO bile duct ligation (KO-BDL) mice than in wild-type-BDL mice. Necroptotic stimuli caused the death of HT-29 and U937 cells. However, necroptotic stimuli activate HSCs instead of inducing cell death. MLKL inhibitors attenuated fibrogenic changes in HSCs during necroptosis. Unlike HT-29 and U937 cells, MLKL phosphorylation and oligomerization were not observed during necroptosis in HSCs. RNA sequencing showed that NF-κB signaling-related genes were upregulated in HSCs following necroptotic stimulation. Necroptotic stimuli in HSCs increased the nuclear expression of NF-κB, which decreased after MLKL inhibitor treatment. Induction of necroptosis in HSCs led to autophagosome activation and formation, which were attenuated by MLKL inhibitor treatment.

CONCLUSION

HSCs avoid necroptosis due to the absence of MLKL phosphorylation and oligomerization and are activated through autophagosome and NF-κB pathways.

Macrophages Serve as Bidirectional Regulators and Potential Therapeutic Targets for Liver Fibrosis

Liver fibrosis is a dynamic pathological process in which the structure and function of the liver abnormally change due to long-term complex inflammatory reactions and chronic liver injury caused by multiple internal and external factors. Previous studies believed that the activation of hepatic stellate cells is a critical part of the occurrence and development of liver fibrosis. However, an increasing number of studies have indicated that the macrophage plays an important role as a central regulator in liver fibrosis, and it directly affects the development and recovery of liver fibrosis. Studies of macrophages and liver fibrosis in the recent 10 years will be reviewed in this paper. This review will not only clarify the molecular mechanism of liver fibrosis regulated by macrophages but also provide new strategies and methods for ameliorating and treating liver fibrosis.

Isovitexin alleviates hepatic fibrosis by regulating miR-21-mediated PI3K/Akt signaling and glutathione metabolic pathway: based on transcriptomics and metabolomics

BACKGROUND

Effective drugs for the treatment of hepatic fibrosis have not yet been identified. Isovitexin (IVT) is a promising hepatoprotective agent owing to its efficacy against acute liver injury. However, the role of IVT in liver fibrosis has not been reported.

PURPOSE

To explore the effect of IVT on liver fibrosis both in vitro and in vivo.

STUDY DESIGN AND METHODS

A mouse model of liver fibrosis induced by carbon tetrachloride (CCl4) and two types of hepatic stellate cell models induced by platelet-derived growth factor-BB (PDGF-BB) were established to evaluate the effect of IVT on hepatic fibrosis. Transcriptomics and metabolomics were used to predict the underlying targets of IVT and were validated by a combination of in vitro and in vivo experiments. Exploration of miRNA and N6-methyladenosine (m6A) modifications was also carried out to detect the key upstream targets of the above targets.

RESULTS

IVT reduced collagen deposition and hepatic stellate cell activation to alleviate liver fibrosis. The transcriptomics and metabolomics analyses showed that phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling and the glutathione (GSH) metabolic pathway may be the main regulatory processes of IVT in hepatic fibrosis. Both the in vitro and in vivo experiments confirmed the inhibitory effect of IVT on the PTEN-PI3K-Akt-mTOR axis and activation of the GSH metabolic pathway. A miR-21 mimic inhibited the effects of IVT on these two pathways, suggesting that miR-21 is the hub for IVT regulation of PI3K-Akt signaling and the GSH metabolic pathway. IVT also increased pri-miR-21 level and reduced the m6A enrichment of pri-miR-21, demonstrating that IVT may regulate pri-miR-21 through m6A modification, thereby affecting the maturation of miR-21.

CONCLUSION

This study is the first to propose a protective effect of IVT against liver fibrosis. The mechanism of IVT against hepatic fibrosis is based on the regulation of miR-21, targeting PTEN-Akt signaling and the GSH metabolic pathway, which is also a novel discovery.

Schisandrin B promotes senescence of activated hepatic stellate cell via NCOA4-mediated ferritinophagy

CONTEXT

Schisandrin B (Sch B), an active ingredient from Schisandrae chinensis (Turcz.) Baill. (Schisandraceae) Fructus, possesses diverse pharmacological activities including antitumor, anti-inflammation, and hepatoprotection.

OBJECTIVE

To explore the effect of Sch B on activated HSCs senescence in hepatic fibrosis and the mechanisms implicated.

MATERIALS AND METHODS

ICR mice with CCl₄-induced hepatic fibrosis were supplemented with Sch B (40 mg/kg) for 30 d and LX2 cells were treated with Sch B (5, 10 and 20 μM) for 24 h. Cellular senescence was assessed by senescence-related indicators senescence-associated β-galactosidase (SA-β-gal) activity and the expression of p16, p21, p53, γ-H2AX, H3K9me3, TERT, TRF1, and TRF2. Ferric ammonium citrate (FAC) and NCOA4 siRNA were used to evaluate the mechanisms underlying Sch B's regulation of cellular senescence.

RESULTS

Sch B (40 mg/kg) reduced serum levels of AST and ALT (53.2% and 63.6%), alleviated hepatic collagen deposition, and promoted activated HSCs senescence in mice. Treatment with Sch B (20 μM) decreased cell viability to 80.38 ± 4.87% and elevated SA-β-gal activity, with the levels of p16, p21 and p53 increased by 4.5-, 2.9-, and 3.5-fold and the levels of TERT, TRF1 and TRF2 decreased by 2.4-, 2.7-, and 2.6-fold in LX2 cells. FAC (400 μM) enhanced Sch B's effect mentioned above. NCOA4 siRNA weakened the effects of Sch B on iron deposition and HSCs senescence.

CONCLUSIONS

Sch B could ameliorate hepatic fibrosis through the promotion of activated HSCs senescence, which might be attributed to its induction of NCOA4-mediated ferritinophagy and subsequent iron overload.

Proanthocyanidin A2 attenuates the activation of hepatic stellate cells by activating the PPAR-γ signalling pathway

Liver fibrosis is the pathological process of chronic liver diseases induced by hepatic stellate cells. Proanthocyanidin A2 (PA2) has multiple pharmacological activities. In this study, we aimed to explore the effects of PA2 on hepatic stellate cell (HSC) activation in liver fibrosis. LX-2 cells were treated with TGF-β1 to establish a fibrosis cell model. Cell viability was evaluated using cell counting kit-8. The levels of fibrosis-related factors (collagen I, fibronectin, and α-SMA) were examined using quantitative real-time polymerase chain reaction, western blot, and immunofluorescence assay. The molecular mechanisms of PA2 were evaluated by RNA-seq, bioinformatic analysis, and western blot. The results showed that PA2 suppressed cell viability, and downregulated fibrosis-related factors induced by TGF-β1, suggesting PA2 suppressed the activation of HSCs. PA2 treatment-induced differentially expressed mRNAs are predicted to be associated with the PPAR-γ pathway. PA2 reversed the downregulation of PPAR-γ and the upregulation of phosphorylated (p)-Smad2 and Smad3. A rescue experiment illustrated that the inactivation of the PPAR-γ pathway reversed the effects of PA2 on cell viability and HSC activation. In conclusion, PA2 inhibited TGF-β1-induced activation of HSCs by activating the PPAR-γ/Smad pathway. The findings suggested that PA2 may be an effective treatment for liver fibrosis.

Reversal of fibrosis and portal hypertension by Empagliflozin treatment of CCl4-induced liver fibrosis: Emphasis on gal-1/NRP-1/TGF-β and gal-1/NRP-1/VEGFR2 pathways

To date, liver fibrosis has no clinically approved treatment. Empagliflozin (EMPA), a highly selective sodium-glucose-cotransporter-2 (SGLT2) inhibitor, has shown ameliorative potential in liver diseases without revealing its full mechanisms. Neuropilin-1 (NRP-1) is a novel regulator of profibrogenic signaling pathways related to hepatic stellate cells (HSCs) and hepatic sinusoidal endothelial cells (HSECs) that modulates intrahepatic profibrogenic and angiogenic pathways. Herein, EMPA's antifibrotic potentials and effects on galactin-1 (Gal-1)/NRP-1 signaling pathways have been evaluated in an experimental liver fibrosis rat model by testing different EMPA dose regimens. EMPA treatment brought a dose-dependent decrease in Gal-1/NRP-1 hepatic expression. This was coupled with suppression of major HSCs pro-fibrotic pathways; transforming growth factor-β (TGF-β)/TGF-βRI/Smad2 and platelet-derived growth factor-beta (PDGF-β) with a diminution of hepatic Col 1A1 level. In addition, EMPA prompted a protuberant suppression of the angiogenic pathway; vascular endothelial growth factor (VEGF)/VEGF-receptor-2 (VEGFR-2)/SH2-Domain Containing Adaptor Protein-B (Shb), and reversal of altered portal hypertension (PHT) markers; endothelin-1 (ET-1) and endothelial nitric oxide synthase (eNOS). The amelioration of liver fibrosis was coupled with a remarkable improvement in liver aminotransferases and histologic hepatic fibrosis Ishak scores. The highest EMPA dose showed a good safety profile with minimal changes in renal function and glycemic control. Thus, the current study brought about novel findings for a potential liver fibrosis treatment modality via targeting NRP-1 signaling pathways by EMPA.

Polyenylphosphatidylcholine as bioactive excipient in tablets for the treatment of liver fibrosis

Liver fibrosis is a condition characterized by the accumulation of extracellular matrix (ECM) arising from the myofibroblastic transdifferentiation of hepatic stellate cells (HSCs) occurring as the natural response to liver damage. To date, no pharmacological treatments have been specifically approved for liver fibrosis. We recently reported a beneficial effect of polyenylphosphatidylcholines (PPCs)-rich formulations in reverting fibrogenic features of HSCs. However, unsaturated phospholipids' properties pose a constant challenge to the development of tablets as preferred patient-centric dosage form. Profiting from the advantageous physical properties of the PPCs-rich Soluthin® S 80 M, we developed a tablet formulation incorporating 70% w/w of this bioactive lipid. Tablets were characterized via X-ray powder diffraction, thermogravimetry, and Raman confocal imaging, and passed the major compendial requirements. To mimic physiological absorption after oral intake, phospholipids extracted from tablets were reconstituted as protein-free chylomicron (PFC)-like emulsions and tested on the fibrogenic human HSC line LX-2 and on primary cirrhotic rat hepatic stellate cells (PRHSC). Lipids extracted from tablets and reconstituted in buffer or as PFC-like emulsions exerted the same antifibrotic effect on both activated LX-2 and PRHSCs as observed with plain S 80 M liposomes, showing that the manufacturing process did not interfere with the bioactivity of PPCs.

LncRNA-Gm9866 promotes liver fibrosis by activating TGFβ/Smad signaling via targeting Fam98b

OBJECTIVE

The exact mechanism and target molecules of liver fibrosis have remained largely elusive. Here, we investigated the role of long noncoding RNA Gm9866(lncRNA-Gm9866) on liver fibrosis.

METHODS

The transcription of lncRNA-Gm9866 in activated cells and mouse fibrotic livers was determined by quantitative polymerase chain reaction (qRT-PCR). The effects of lentivirus-mediated knockdown or overexpression of lncRNA-Gm9866 in liver fibrosis were examined in vitro and in vivo. Furthermore, bioinformatics analysis, cell samples validation, fluorescence in situ hybridization (FISH) co-localization, RNA binding protein immunoprecipitation (RIP), actinomycin D test and Western blot (WB) were carried out to explore the potential mechanism of lncRNA-Gm9866.

RESULTS

The expression of α-smooth muscle actin (α-SMA), Collagen I (COL-1) and lncRNA-Gm9866 were significantly increased in tissues and cells. Overexpressing lncRNA-Gm9866 promoted the activation of hepatic stellate cells (HSCs). Silencing lncRNA-Gm9866 inhibited the activation of HSCs and transforming growth factor-β1 (TGFβ1) induced fibrosis. Overexpressing lncRNA-Gm9866 promoted hepatocytes (HCs) apoptosis and the expression of pro-fibrogenic genes, inhibited the proliferation and migration of HCs. Knockdown of lncRNA-Gm9866 inhibited the apoptosis of HCs, the expression of pro-fibrogenic genes, TGFβ1 induced fibrosis and the occurrence of carbon tetrachloride (CCl4)-induced liver fibrosis, and promoted the proliferation and migration of HCs. Mechanistically, lncRNA-Gm9866 may directly bine with Fam98b. Silencing Fam98b in stably overexpressing lncRNA-Gm9866 cell lines reversed the increase of pro-fibrogenic genes and pro-apoptotic genes, fibrosis related pathway protein TGFβ1, Smad2/3, p-Smad2/3 and Notch3 induced by overexpressing lncRNA-Gm9866.

CONCLUSIONS

LncRNA-Gm9866 may regulate TGFβ/Smad and Notch pathways by targeting Fam98b to regulate liver fibrosis. LncRNA-Gm9866 may be a new target for diagnosis and treatment of liver fibrosis.

Pterostilbene exerts cytotoxicity on activated hepatic stellate cells by inhibiting excessive proliferation through the crosstalk of Sirt1 and STAT3 pathways

Pterostilbene (PTE), a natural analogue of resveratrol, abundantly exists in blueberries and grapes and has several beneficial potentials against oxidative stress, inflammation, and cancer. In current study, we investigated the effects of PTE on hepatic fibrosis in vitro and in vivo. Activation of hepatic stellate cells (HSCs) is an initiating event in the initiation of hepatic fibrosis. MTT assay revealed that PTE (3.125-12.5 μM) displayed cytotoxicity on activated HSCs, no cytotoxicity on AML-12 and quiescent HSCs. PTE significantly inhibited the expressions of α-SMA, collagen Ⅰ and TIMP-1/MMP13 ratio; suppressed inflammatory cascade activation to reduce inflammatory cytokines release, such as Caspase-1, IL-1β and IL-6. PTE activated Sirt1 and decreased STAT3 phosphorylation, functioning as SRT1720 and Niclosamide. Sirt1 deficiency significantly elevated p-STAT3 expression, while STAT3 deficiency resulted in Sirt1 increasing and inhibited fibrosis and inflammatory cytokines expressions. In mice with hepatic fibrosis induced by thioacetamide (TAA), PTE significantly decreased ALT and AST activities, reduced fibrosis markers, STAT3 phosphorylation and activated Sirt1 expression. PTE showed cytotoxicity on activated HSCs to ameliorate hepatic fibrosis via regulating fibrogenesis, energy metabolism and inflammation and targeting the crosstalk of Sirt1 and STAT3. In conclusion, PTE could be potentially beneficial as a natural plant metabolite in preventing and treating hepatic fibrosis.