Doxazosin Attenuates Liver Fibrosis by Inhibiting Autophagy in Hepatic Stellate Cells via Activation of the PI3K/Akt/mTOR Signaling Pathway

TIMP-1 Promotes Expression of MCP-1 and Macrophage Migration by Inducing Fli-1 in Experimental Liver Fibrosis

Background and Aims

Tissue inhibitor of metalloproteinase-1 (TIMP-1) plays a role in the excessive generation of extracellular matrix in liver fibrosis. This study aimed to explore the pathways through which TIMP-1 controls monocyte chemoattractant protein-1 (MCP-1) expression and promotes hepatic macrophage recruitment.

Methods

Liver fibrosis was triggered through carbon tetrachloride, and an adeno-associated virus containing small interfering RNA targeting TIMP-1 (siRNA-TIMP-1) was administered to both rats and mice. We assessed the extent of fibrosis and macrophage recruitment. The molecular mechanisms regulating macrophage recruitment by TIMP-1 were investigated through transwell migration assays, luciferase reporter assays, the use of pharmacological modulators, and an analysis of extracellular vesicles (EVs).

Results

siRNA-TIMP-1 alleviated carbon tetrachloride-induced liver fibrosis, reducing macrophage migration and MCP-1 expression. Co-culturing macrophages with hepatic stellate cells (HSCs) post-TIMP-1 downregulation inhibited macrophage migration. In siRNA-TIMP-1-treated HSCs, microRNA-145 (miRNA-145) expression increased, while the expression of Friend leukemia virus integration-1 (Fli-1) and MCP-1 was inhibited. Downregulation of Fli-1 led to decreased MCP-1 expression, whereas Fli-1 overexpression increased MCP-1 expression within HSCs. Transfection with miRNA-145 mimics reduced the expression of both Fli-1 and MCP-1, while miRNA-145 inhibitors elevated the expression of both Fli-1 and MCP-1 in HSCs. miRNA-145 bound directly to the 3'-UTR of Fli-1, and miRNA-145-enriched EVs secreted by HSCs after TIMP-1 downregulation influenced macrophage recruitment.

Conclusions

TIMP-1 induces Fli-1 expression through miRNA-145, subsequently increasing MCP-1 expression and macrophage recruitment. MiRNA-145-enriched EVs from HSCs can transmit biological information and magnify the function of TIMP-1.

Guizhi Fuling Wan attenuates tetrachloromethane-induced hepatic fibrosis in rats via PTEN/AKT/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Treatment options for hepatic fibrosis, a prevalent liver condition closely linked to cirrhosis, are currently limited. While Guizhi Fuling Wan (GFW), a pill derived from traditional Chinese herbs, has been reported to possess hepatoprotective properties, its therapeutic effect and mechanism in hepatic fibrosis remain elusive.

AIM OF THE STUDY

This study aimed to evaluate the anti-fibrotic impact of GFW and its underlying mechanisms in both in vivo and in vitro settings.

MATERIALS AND METHODS

Tetrachloromethane (CCl4) was used to induce hepatic fibrosis in male rats. In vitro, activation of hepatic stellate cells (HSCs) was triggered by platelet-derived growth factor-BB (PDGF-BB). In vivo, liver function, pathological alterations, and HSC activation were evaluated. Additionally, the impact of GFW on the activated phenotypes of Lieming Xu-2 (LX-2) cells was examined in vitro. Network pharmacology was employed to identify the potential targets of GFW in hepatic fibrosis. Lastly, the impact of GFW on the PTEN/AKT/mTOR pathway and PTEN ubiquitination in HSCs was investigated.

RESULTS

GFW alleviated CCl4-induced liver damage and scarring in rats in a dose-dependent manner and suppressed HSC activation in vivo. Moreover, GFW inhibited the proliferation, migration, differentiation, and extracellular matrix (ECM) production of activated HSCs in vitro. GFW also promoted autophagy and apoptosis of HSCs. Meanwhile, network pharmacology and in vitro studies suggested that GFW inhibits the AKT/mTOR pathway by preventing PTEN degradation by suppressing ubiquitination.

CONCLUSION

GFW attenuates Ccl4-induced hepatic fibrosis in male rats by regulating the PTEN/AKT/mTOR signaling pathway, positioning it as a potential candidate for the treatment of hepatic fibrosis.

Bone mesenchymal stem cells improve cholestatic liver fibrosis by targeting ULK1 to regulate autophagy through PI3K/AKT/mTOR pathway

Cholestatic liver disease (CLD) is a severe disease, which can progress to liver cirrhosis, even liver cancer. Hepatic stellate cells (HSCs) activation plays a crucial role in CLD development. Bone mesenchymal stem cells (BMSCs) treatment was demonstrated to be beneficial in liver diseases. However, the therapeutic effect and mechanism of BMSCs on CLD are poorly known. In the present study, we investigated the therapeutic effects and underlying mechanisms of BMSCs transplantation in mouse models of bile duct ligation-induced cholestatic liver fibrosis (CLF). The results revealed that BMSCs significantly improved liver function and reduced the formation of fibrosis after portal vein transplantation. Mechanistically, after coculturing BMSCs and HSCs, we identified that BMSCs alleviated starvation-induced HSCs activation. Further, BMSCs inhibited HSCs activation by decreasing autophagy, and PI3K/AKT/mTOR pathway was involved in the regulation. More importantly, ULK1 is identified as the main autophagy-related gene regulated by BMSCs in HSCs autophagy. Overexpression of ULK1 reversed the suppression of HSCs autophagy by BMSCs. Collectively, our results provide a theoretical basis for BMSCs targeting ULK1 to attenuate HSCs autophagy and activation and suggest that BMSCs or ULK1 may be an alternative therapeutic approach/target for the treatment of CLF.

Progress of mesenchymal stem cells (MSCs) & MSC-Exosomes combined with drugs intervention in liver fibrosis

Liver fibrosis is an intrahepatic chronic damage repair response caused by various reasons such as alcoholic liver, fatty liver, viral hepatitis, autoimmune diseases, etc., and is closely related to the progression of liver disease. Currently, the mechanisms of liver fibrosis and its treatment are hot research topics in the field of liver disease remedy. Mesenchymal stem cells (MSCs) are a class of adult stem cells with self-renewal and multidirectional differentiation potential, which can ameliorate fibrosis through hepatic-directed differentiation, paracrine effects, and immunomodulation. However, the low inner-liver colonization rate, low survival rate, and short duration of intervention after stem cell transplantation have limited their wide clinical application. With the intensive research on liver fibrosis worldwide, it has been found that MSCs and MSCs-derived exosomes combined with drugs have shown better intervention efficiency than utilization of MSCs alone in many animal models of liver fibrosis. In this paper, we review the interventional effects and mechanisms of mesenchymal stem cells and their exosomes combined with drugs to alleviate hepatic fibrosis in vivo in animal models in recent years, which will provide new ideas to improve the efficacy of mesenchymal stem cells and their exosomes in treating hepatic fibrosis in the clinic.

CircUTRN24/miR-483-3p/IGF-1 Regulates Autophagy Mediated Liver Fibrosis in Biliary Atresia

Biliary atresia (BA) is a rare neonatal cholestatic disease that presents with a marked bile duct reaction and rapid fibrotic development. Our earlier research has shown that circUTRN24 is highly elevated in BA, but the exact molecular mechanism is still unknown. This study attempted to investigate whether circUTRN24 induces BA liver fibrosis through regulation of autophagy and to elucidate its molecular mechanism. Using TGF-β-treated hepatic stellate cells (HSC) LX-2, we created a liver fibrosis model. qRT-PCR was used to analyze the expression of circUTRN24, miR-483-3p, and IGF-1. Western blot analysis was used to assess the expression of IGF-1, HSC activation-related proteins, and autophagy-related proteins. The TGF-β-induced LX-2 cell fibrosis model was then supplemented with circUTRN24 siRNA, miR-483-3p mimics, and the autophagy activator Rapamycin, and functional rescue tests were carried out to investigate the role of circUTRN24, miR-483-3p, and autophagy in BA liver fibrosis. Using a luciferase reporter assay, a direct interaction between miR-483-3p and circUTRN24 or IGF-1 was discovered. With the increase of TGF-β treatment concentration, circUTRN24 expression also gradually increased, as did HSC activation and autophagy-related protein. si-circUTRN24 significantly decreased circUTRN24 expression and inhibited HSC activation and autophagy, which was reversed by Rapamycin. Through bioinformatics prediction and validation, we found circUTRN24 might act through miR-483-3p targeting IGF-1 in the autophagy-related mTOR pathway. Furthermore, miR-483-3p mimics significantly increased miR-483-3p expression and inhibited HSC activation and autophagy, which were reversed by Rapamycin. Functional rescue experiments showed that si-circUTRN24 inhibited circUTRN24 and IGF-1 expressions and promoted miR-483-3p expression, while the miR-483-3p inhibitor abolished these effects. These findings imply that circUTRN24/miR-483-3p/IGF-1 axis mediated LX-2 cell fibrosis by regulating autophagy.

Lysine specific demethylase 1 inhibits sodium arsenite activation of HSCs by regulating SESN2/AMPK/ULK1 signaling pathway activity

Lysine specific demethylase 1 (LSD1) is a histone demethylase that specifically catalyzes the demethylation of histone H3K4 (H3K4me1/2) and regulates gene expression. In addition, it can mediate the process of autophagy through its demethylase activity. Sestrin2 (SESN2) is a stress-induced protein and a positive regulator of autophagy. In NaAsO2-induced mouse fibrotic livers and activated hepatic stellate cells (HSCs), LSD1 expression is decreased, SESN2 expression is increased, and autophagy levels are also increased. Overexpression of LSD1 and silencing of SESN2 decreased the level of autophagy and attenuated the activation of HSCs induced by NaAsO2. LSD1 promoted SESN2 gene transcription by increasing H3K4me1/2 in the SESN2 promoter region. 3-methyladenine (3-MA) and chloroquine were used to inhibit autophagy of HSCs, and the degree of activation was also alleviated. Taken together, LSD1 positively regulates SESN2 by increasing H3K4me1/2 enrichment in the SESN2 promoter region, which in turn increases the level of autophagy and promotes the activation of HSCs. Our results may provide new evidence for the importance of LSD1 in the process of autophagy and activation of HSCs induced by arsenic poisoning. Increasing the expression and activity of LSD1 is expected to be an effective way to reverse the autophagy and activation of HSCs induced by arsenic poisoning.

The α-1 Adrenergic Receptor Antagonist Doxazosin Attenuates Liver Fibrosis by Alleviating Sinusoidal Capillarization and Liver Angiogenesis

Liver fibrosis and cirrhosis, which are caused by chronic liver injury, represent common and intractable clinical challenges of global importance. However, effective therapeutics are lacking. Therefore, the study examines the effect of doxazosin on liver fibrosis. Carbon tetrachloride (CCl4) is injected into mice to establish a liver fibrosis model. Doxazosin (5 and 10 mg/kg) is administered daily by gavage. HE staining, Masson staining, Sirius Red staining, scanning electron microscopy, western blotting, real-time PCR, and immunofluorescence analysis are performed to estimate liver fibrosis and sinusoidal capillarization in mice. Cell Counting Kit-8 assays, western blotting, immunofluorescence analysis, tube formation, and transwell migration assays are performed on human umbilical vein endothelial cells (HUVECs) and human hepatic sinusoidal endothelial cells (HHSECs) to elucidate the potential mechanism of doxazosin. Doxazosin alleviates liver fibrosis and sinusoidal capillarization in CCl4-induced mice. Angiogenesis is attenuated by doxazosin in HUVECs and HHSECs. This study demonstrates that doxazosin attenuated liver fibrosis by alleviating sinusoidal capillarization and liver angiogenesis.

Dihydromyricetin alleviates inflammatory bowel disease associated intestinal fibrosis by inducing autophagy through the PI3K/AKT/mTOR signaling pathway

Intestinal fibrosis is a common complication of inflammatory bowel disease and is characterized by tissue stiffening and luminal narrowing. Dihydromyricetin (DHM) can alleviate liver fibrosis and renal interstitial fibrosis by inducing autophagy. However, whether DHM can alleviate intestinal fibrosis remains unclear. This study is aimed at evaluating the role and mechanism of action of DHM in inflammatory bowel disease-associated intestinal fibrosis. Mice were administered dextran sulfate sodium (DSS) in drinking water to induce inflammatory bowel disease-associated intestinal fibrosis. HE staining, qPCR, and Western blotting were used to analyze colon inflammation. Masson's trichrome staining, qPCR, Western blotting, and immunofluorescence staining were used to evaluate the severity of fibrosis. Transmission electron microscopy and Western blotting were used to assess the activation of autophagosomes. The human colonic fibroblast line CCD-18Co was cultured in the presence of TGF-β1 to develop a fibrotic phenotype. Immunofluorescence staining, Western blotting, and qPCR were used to assess the alteration of fibrosis markers and used to investigate whether DHM-induced autophagy was involved in the inactivation of CCD-18Co cells. Additionally, the role of the PI3K/AKT/mTOR pathway was investigated. DHM alleviated intestinal inflammation and inhibited the progression of intestinal fibrosis. Additionally, DHM induced the activation of autophagy, thereby alleviating intestinal fibrosis, and downregulated the PI3K/AKT/mTOR signaling pathway in vitro. Overall, this study demonstrated that DHM can inhibit the progression of intestinal fibrosis and activation of colonic fibroblasts by inducing autophagy through the PI3K/AKT/mTOR signaling pathway, thereby playing a preventive and therapeutic role in intestinal fibrosis.

CD47, a novel YAP target gene, contributes to hepatic stellate cell activation and liver fibrosis induced by high-fat diet

Activated hepatic stellate cells (HSCs) have been widely recognized as a primary source of pathological myofibroblasts, leading to the accumulation of extracellular matrix and liver fibrosis. CD47, a transmembrane glycoprotein expressed on the surface of various cell types, has been implicated in non-alcoholic fatty liver disease. However, the precise role of CD47 in HSC activation and the underlying regulatory mechanisms governing CD47 expression remain poorly understood. In this study, we employed single-cell RNA sequencing analysis to investigate CD47 expression in HSCs from mice subjected to a high-fat diet. CD47 silencing in HSCs markedly inhibited the expression of fibrotic genes and promoted apoptosis. Mechanistically, we found that Yes-associated protein (YAP) collaborates with TEAD4 to augment the transcriptional activation of CD47 by binding to its promoter region. Notably, disruption of the interaction between YAP and TEAD4 caused a substantial decrease in CD47 expression in HSCs and reduced the development of high-fat diet-induced liver fibrosis. Our findings highlight CD47 as a critical transcriptional target of YAP in promoting HSC activation in response to a high-fat diet. Targeting the YAP/TEAD4/CD47 signaling axis may hold promise as a therapeutic strategy for liver fibrosis.

Galectin-receptor interaction: a key player in liver fibrosis induced by Schistosoma japonicum infection

BACKGROUND

Schistosoma japonicum eggs lodge in the liver and induce a fibrotic granulomatous immune response in the liver of host. Galectin 3 (Gal-3) is a protein implicated in fibrosis in multiple organs. However, the pathology and molecular mechanisms promoting hepatic granuloma formation remain poorly understood.

METHODS

To investigate the effect of blocking galectin-receptor interactions by α-lactose on liver immunopathology in mice with S. japonicum infection, C57BL/6 mice were infected with S. japonicum and alpha (α)-lactose was intraperitoneally injected to block the interactions of galectins and their receptors.

RESULTS

Compared with S. japonicum-infected mice, there were significantly decreased Gal-3 mRNA and protein expression levels, decreased intensity of Gal-3 fluorescence in the liver, decreased serum ALT and AST levels, decreased egg numbers of S. japonicum in the liver section, attenuated hepatic and spleen pathology, and alleviated liver fibrosis accompanied with decreased protein expression levels of fibrosis markers [α-smooth muscle actin (α-SMA), collagen I, and collagen IV] in the liver of S. japonicum-infected mice blocked galectin-receptor interactions with hematoxylin-eosin staining, Masson's trichrome staining, immunohistochemistry, or Western blot analysis. Compared with S. japonicum-infected mice, blocking galectin-receptor interactions led to increased eosinophil infiltration and higher eosinophil cationic protein (ECP) expression in the liver, accompanied by increased mRNA levels of eosinophil granule proteins [ECP and eosinophil peroxidase (EPO)], IL-5, CCL11, and CCR3 in the liver and decreased mRNA levels of Gal-3 and M2 macrophage cytokines (TGF-β, IL-10, and IL-4) in the liver and spleen by using quantitative real-time reverse transcription-polymerase chain reaction. In addition, there were increased Beclin1 protein expression and protein expression ratio of LC3B-II/LC3B-I and decreased p62 protein expression and protein expression ratios of phospho-mTOR/mTOR and phospho-AKT/AKT by Western blot; increased double-labeled F4/80+/LC3B+ cells by immunofluorescence staining; increased M1 macrophage polarization in the liver of S. japonicum-infected mice blocked galectin-receptor interactions by flow cytometric analysis and immunofluorescence staining.

CONCLUSIONS

Our data found that blockage of galectin-receptor interactions downregulated Gal-3, which in turn led to reduced liver functional damage, elevated liver eosinophil recruitment, promoted macrophage autophagy through the Akt/mTOR signaling pathway, and alleviated liver pathology and fibrosis. Therefore, Gal-3 plays a pivotal role during S. japonicum infection and could be a target of pharmacologic potential for liver fibrosis induced by S. japonicum infection.

The role of PI3k/AKT signaling pathway in attenuating liver fibrosis: a comprehensive review

Excessive accumulation of extracellular matrix (ECM) components within the liver leads to a pathological condition known as liver fibrosis. Alcohol abuse, non-alcoholic fatty liver disease (NAFLD), autoimmune issues, and viral hepatitis cause chronic liver injury. Exploring potential therapeutic targets and understanding the molecular mechanisms involved in liver fibrosis are essential for the development of effective interventions. The goal of this comprehensive review is to explain how the PI3K/AKT signaling pathway contributes to the reduction of liver fibrosis. The potential of this pathway as a therapeutic target is investigated through a summary of results from in vivo and in vitro studies. Studies focusing on PI3K/AKT activation have shown a significant decrease in fibrosis markers and a significant improvement in liver function. The review emphasizes how this pathway may prevent ECM synthesis and hepatic stellate cell (HSC) activation, ultimately reducing the fibrotic response. The specific mechanisms and downstream effectors of the PI3K/AKT pathway in liver fibrosis constitute a rapidly developing field of study. In conclusion, the PI3K/AKT signaling pathway plays a significant role in attenuating liver fibrosis. Its complex role in regulating HSC activation and ECM production, demonstrated both in vitro and in vivo, underscores its potential as a effective therapeutic approach for managing liver fibrosis and slowing disease progression. A comprehensive review of this field provides valuable insights into its future developments and implications for clinical applications.

Cannabidiol regulates the activation of hepatic stellate cells by modulating the NOX4 and NF-κB pathways

Cannabidiol (CBD) is an extract of natural cannabinoids that has therapeutic implications for a variety of ailments, such as neurological diseases, cardiomyopathy, and diabetes, due to its strong anti-inflammatory and oxidative stress properties. Our purpose was to reveal the possible underlying mechanisms and effect of CBD on the glucose oxidase (GO)-induced activation of HSC-T6 and LX-2 cells. The results showed that CBD effectively inhibited the proliferation and activation of HSC-T6 and LX-2 cells, and reduced the production of profibrotic factors to different degrees. CBD disrupted the NOX4 signalling pathway in activated HSC-T6 and LX-2 cells, reduced ROS and MDA levels, and increased SOD and GSH levels, thereby stabilizing the oxidative imbalance. CBD significantly inhibited the phosphorylation and degradation of NF-κB and IκBα, and decreased the release of TNF-α, IL-1β and IL-6. Moreover, CBD and an NF-κB-specific inhibitor (CAPE) effectively inhibited the expression of α-SMA, COL I, TNF-α and IL-1β to promote collagen metabolism and inhibit the inflammatory response. Overall, CBD inhibited HSCs activation through a and the mechanism involving the inhibition of NOX4 and NF-κB-dependent ROS regulation, thereby reducing inflammation and ameliorating oxidative imbalances.

Network Pharmacology, Molecular Docking Analysis and Molecular Dynamics Simulation of Scutellaria baicalensis in the Treatment of Liver Fibrosis

BACKGROUND

Traditional Chinese medicine Scutellaria Baicalensis (SB), one of the clinical firstline heat-clearing drugs, has obvious symptomatic advantages for hepatic fibrosis with dampness-heat stasis as its syndrome. We aim to predict and validate the potential mechanism of Scutellaria baicalensis active ingredients against liver fibrosis more scientifically and effectively.

METHODS

The underlying mechanism of Scutellaria baicalensis in inhibiting hepatic fibrosis was studied by applying network pharmacology, molecular docking and molecular dynamics simulation. Expression levels of markers in activated Hepatic Stellate Cells (HSC) after administration of three Scutellaria baicalensis extracts were determined by Western blot and Real-time PCR, respectively, in order to verify the anti-fibrosis effect of the active ingredients Results: There are 164 common targets of drugs and diseases screened and 115 signaling pathways obtained, which were mainly associated with protein phosphorylation, senescence and negative regulation of the apoptotic process. Western blot and Real-time PCR showed that Scutellaria baicalensis extracts could reduce the expression of HSC activation markers, and Oroxylin A had the strongest inhibitory effect on it. Molecular docking results showed that Oroxylin A had high binding activity to target proteins. Molecular dynamics simulation demonstrates promising stability of the Oroxylin A-AKT1 complex over the simulated MD time of 200 ns.

CONCLUSION

Scutellaria baicalensis active ingredients may inhibit HSC proliferation, reduce the generation of pro-inflammatory factors and block the anti-inflammatory effect of inflammatory signal transduction by inducing HSC apoptosis and senescence, thus achieving the effect of anti-fibrosis.

Research Progress on the Effect of Autophagy and Exosomes on Liver Fibrosis

Chronic liver disease is a known risk factor for the development of liver cancer, and the development of microRNA (miRNA) liver therapies has been hampered by the difficulty of delivering miRNA to damaged tissues. In recent years, numerous studies have shown that hepatic stellate cell (HSC) autophagy and exosomes play an important role in maintaining liver homeostasis and ameliorating liver fibrosis. In addition, the interaction between HSC autophagy and exosomes also affects the progression of liver fibrosis. In this paper, we review the research progress of mesenchymal stem cell-derived exosomes (MSC-EVs) loaded with specific miRNA and autophagy, and their related signaling pathways in liver fibrosis, which will provide a more reliable basis for the use of MSC-EVs for therapeutic delivery of miRNAs targeting the chronic liver disease.

Long non-coding RNA growth arrest-specific 5 inhibits liver fibrogenesis in biliary atresia by interacting with microRNA-222 and repressing IGF1/AKT signaling

Background

Long non-coding RNA growth arrest-specific 5 (lncRNA GAS5) has been shown to inhibit liver fibrosis through serving as a competing endogenous RNA for microRNA-222 (miR-222). Progressive liver fibrosis is a typical characteristic of biliary atresia (BA). However, the role of GAS5/miR-222 and its underlying mechanisms remain largely unknown in BA.

Methods

The expression of GAS5 was determined in the liver and primary hepatic stellate cells (HSCs) of BA patients. Then, the effects of GAS5 on the activation and proliferation of HSCs were evaluated. Furthermore, the interaction between GAS5 and miR-222 was investigated by a luciferase gene report assay. Next, the effects of IGF1/AKT signaling were determined to clarify the downstream mechanism of GAS5. Finally, GAS5 administration was performed to explore its role in an experimental BA mouse model.

Results

GAS5 expression was decreased in liver tissues and HSCs of BA patients, and was inversely correlated with liver fibrosis in BA. Up-regulation of GAS5 in LX-2 cells significantly reduced smooth muscle α-actin (α-SMA) and collagen 1a1 (COL1A1) expression, inhibited cell proliferation and clone formation ability, induced S phase increase, and promoted cell apoptosis. Moreover, GAS5 was negatively regulated by miR-222, which promoted HSCs activation and proliferation, and was positively correlated with liver fibrosis in BA. Additionally, the expressions of IGF1, p-PI3K, and p-AKT were decreased when LX-2 cells over-expressed GAS5, whereas knockdown of IGF1 or AKT significantly decreased α-SMA and COL1A1 expression, suppressed cell proliferation, and enhanced cell apoptosis in LX-2 cells. Furthermore, GAS5 administration significantly increased apoptosis and reduced liver fibrosis, α-SMA and COL1A1 expressions in liver tissues of BA mice.

Conclusions

GAS5 inhibited liver fibrosis in BA by interacting with miR-222 and regulating IGF1/AKT signaling, which may be a therapeutic target to alleviate liver fibrosis in BA.

Neuroimmunomodulation of adrenoblockers during liver cirrhosis: modulation of hepatic stellate cell activity

The sympathetic nervous system and the immune system are responsible for producing neurotransmitters and cytokines that interact by binding to receptors; due to this, there is communication between these systems. Liver immune cells and nerve fibres are systematically distributed in the liver, and the partial overlap of both patterns may favour interactions between certain elements. Dendritic cells are attached to fibroblasts, and nerve fibres are connected via the dendritic cell-fibroblast complex. Receptors for most neuroactive substances, such as catecholamines, have been discovered on dendritic cells. The sympathetic nervous system regulates hepatic fibrosis through sympathetic fibres and adrenaline from the adrenal glands through the blood. When there is liver damage, the sympathetic nervous system is activated locally and systemically through proinflammatory cytokines that induce the production of epinephrine and norepinephrine. These neurotransmitters bind to cells through α-adrenergic receptors, triggering a cellular response that secretes inflammatory factors that stimulate and activate hepatic stellate cells. Hepatic stellate cells are key in the fibrotic process. They initiate the overproduction of extracellular matrix components in an active state that progresses from fibrosis to liver cirrhosis. It has also been shown that they can be directly activated by norepinephrine. Alpha and beta adrenoblockers, such as carvedilol, prazosin, and doxazosin, have recently been used to reverse CCl₄-induced liver cirrhosis in rodent and murine models.KEY MESSAGESNeurotransmitters from the sympathetic nervous system activate and increase the proliferation of hepatic stellate cells.Hepatic fibrosis and cirrhosis treatment might depend on neurotransmitter and hepatic nervous system regulation.Strategies to reduce hepatic stellate cell activation and fibrosis are based on experimentation with α-adrenoblockers.

Preparation of Phillygenin-Hyaluronic acid composite milk-derived exosomes and its anti-hepatic fibrosis effect

Liver fibrosis remains a serious problem affecting the health of millions of people worldwide. Hepatic stellate cells (HSCs) are the main effector cells in liver fibrosis and their activation could lead to extracellular matrix deposition, which may aggravate the development of liver fibrosis and inflammation. Previous studies have reported the potential of Phillygenin (PHI) as a hepatoprotective agent to inhibit HSCs activation and fibrosis development. However, the poor water solubility of PHI hinders its clinical application as a potential anti-liver fibrosis therapy. Milk-derived exosomes (mEXO) serve as scalable nanocarriers for delivering chemotherapeutic agents due to their excellent biocompatibility. Here, we developed a PHI-Hyaluronic acid (HA) composite mEXO (PHI-HA-mEXO) drug delivery system, in which DSPE-PEG2000-HA was conjugated to the surface of mEXO to prepare HA-mEXO, and PHI was encapsulated into HA-mEXO to form PHI-HA-mEXO. As a specific receptor for HA, CD44 is frequently over-expressed during liver fibrosis and highly expressed on the surface of activated HSCs (aHSCs). PHI-HA-mEXO can bind to CD44 and enter aHSCs through endocytosis and release PHI. PHI-HA-mEXO drug delivery system can significantly induce aHSCs death without affecting quiescent HSCs (qHSCs) and hepatocytes. Furthermore, we carried out in vitro and in vivo experiments and found that PHI-HA-mEXO could alleviate liver fibrosis through aHSCs-targeted mechanism. In conclusion, the favorable biosafety and superior anti-hepatic fibrosis effects suggest a promising potential of PHI-HA-mEXO in the treatment of hepatic fibrosis. However, detailed pharmokinetics and dose-responsive experiments of PHI-HA-mEXO and the mechanism of mEXO loading drugs are still required before PHI-HA-mEXO can be applied clinically.

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.

Curcumin inhibits the activity and induces apoptosis of activated hepatic stellate cell by suppressing autophagy

Curcumin, a kind of natural compound, has been previously proven to inhibit the autophagy in hepatic stellate cells (HSCs) and induce their apoptosis. However, it is not clear whether the enhanced apoptosis of activated HSCs (aHSCs) caused by curcumin depends on autophagy inhibition. We aim to verify this hypothesis and explore the potential mechanisms in this study. Immortalized human HSC line LX-2 was used as an experimental specimen and pretreated with transforming growth factor β1(TGF-β1) for 24 h to activate it before drug application. The levels of autophagy, apoptosis, cell activity, lipid metabolism, and the activity of the PI3K/Akt/mTOR signal pathway were evaluated by multiple methods, such as Western blotting, mcherry-EGFP-LC3B adenoviruses transfection, immunofluorescence, Nile Red staining, flow cytometry among others. Our results showed that rapamycin, an autophagy activator, could partly offset the effects of curcumin on autophagy and apoptosis of LX-2 cells, while 3-Methyladenine (3-MA), an autophagy inhibitor, could enhance these effects. Furthermore, curcumin could promote the activity of the PI3K/Akt/mTOR signal pathway in LX-2 cells, while PI3K inhibitor could partly offset this effect and increase the autophagy level. Overall, we demonstrated that curcumin could inhibit the activity and promote LX-2 cells apoptosis by suppressing autophagy by activating the PI3K/Akt/mTOR signal pathway. In addition, lipid recovery and energy deprivation due to autophagy inhibition may be the exact mechanism by which curcumin attenuates the pro-fibrotic activity of LX-2.

Single-cell RNA sequencing reveals the heterogeneity and intercellular communication of hepatic stellate cells and macrophages during liver fibrosis

Uncontrolled and excessive progression of liver fibrosis is thought to be the prevalent pathophysiological cause of liver cirrhosis and hepatocellular cancer, and there are currently no effective antifibrotic therapeutic options available. Intercellular communication and cellular heterogeneity in the liver are involved in the progression of liver fibrosis, but the exact nature of the cellular phenotypic changes and patterns of interregulatory remain unclear. Here, we performed single-cell RNA sequencing on nonparenchymal cells (NPCs) isolated from normal and fibrotic mouse livers. We identified eight main types of cells, including endothelial cells, hepatocytes, dendritic cells, B cells, natural killer/T (NK/T) cells, hepatic stellate cells (HSCs), cholangiocytes and macrophages, and revealed that macrophages and HSCs exhibit the most variance in transcriptional profile. Further analyses of HSCs and macrophage subpopulations and ligand-receptor interaction revealed a high heterogeneity characterization and tightly interregulated network of these two groups of cells in liver fibrosis. Finally, we uncovered a profibrotic Thbs1+ macrophage subcluster, which expands in mouse and human fibrotic livers, activating HSCs via PI3K/AKT/mTOR signaling pathway. Our findings decode unanticipated insights into the heterogeneity of HSCs and macrophages and their intercellular crosstalk at a single-cell level, and may provide potential therapeutic strategies in liver fibrosis.

A novel selective estrogen receptor degrader induces cell cycle arrest in breast cancer via ERα degradation and the autophagy-lysosome pathway

Breast cancer (BC), a well-known estrogen-dependent cancer, is the most common cancer among women and the leading cause of cancer deaths. One of the most important therapeutic approaches for BC is endocrine therapy targeting estrogen receptor alpha (ERα) and thus blocking the estrogen receptor signaling pathway. Drugs, such as tamoxifen or fulvestrant, are developed based on this theory and have benefited numerous patients with BC for many years. However, many patients with advanced BC, such as tamoxifen-resistant BC, cannot benefit from these developed drugs anymore. Therefore, new drugs targeting ERα are urgently needed by patients with BC. Recently, elacestrant, a novel selective estrogen receptor degrader (SERD), was approved by the United States Food and Drug Administration (FDA), highlighting the importance of ERα degradation in endocrine therapy. Proteolysis targeting chimera (PROTAC) has been considered a powerful technique for targeting protein degradation (TPD). In this regard, we developed and studied a novel ERα degrader, which is a PROTAC-like SERD named 17e. We found that compound 17e can inhibit the growth of BC both in vitro and in vivo and induce the cell cycle arrest of BC. Importantly, 17e displayed no apparent toxicity toward healthy kidney and liver cells. Moreover, we observed that the presence of 17e led to a dramatic increase in the autophagy-lysosome pathway in an ERα-independent manner. Finally, we revealed that a decrease in MYC, a frequent deregulation oncogene in human cancers, was mediated by both ERα degradation and autophagy activation in the presence of 17e. Collectively, we discovered that compound 17e induced ERα degradation and exerts significant anti-cancer effects on BC mainly through promoting the autophagy-lysosome pathway and decreasing MYC level.

Therapeutic interventions of acute and chronic liver disorders: A comprehensive review

Liver disorders are one of the most common pathological problems worldwide. It affects more than 1.5 billion worldwide. Many types of hepatic cells have been reported to be involved in the initiation and propagation of both acute and chronic liver diseases, including hepatocytes, Kupffer cells, sinusoidal endothelial cells, and hepatic stellate cells (HSCs). In addition, oxidative stress, cytokines, fibrogenic factors, microRNAs, and autophagy are also involved. Understanding the molecular mechanisms of liver diseases leads to discovering new therapeutic interventions that can be used in clinics. Recently, antioxidant, anti-inflammatory, anti-HSCs therapy, gene therapy, cell therapy, gut microbiota, and nanoparticles have great potential for preventing and treating liver diseases. Here, we explored the recent possible molecular mechanisms involved in the pathogenesis of acute and chronic liver diseases. Besides, we overviewed the recent therapeutic interventions that targeted liver diseases and summarized the recent studies concerning liver disorders therapy.

Genes and Signaling Pathways Involved in the Regulation of Selenium-Enriched Yeast on Liver Metabolism and Health of Broiler (Gallus gallus)

Selenium-enriched yeast (SeY) plays an important role in the liver health and metabolism of the broiler. However, the mechanism by which it regulates liver metabolism and the health of broilers is largely unknown. Therefore, this study was conducted to elucidate the key genes and signaling pathways involved in regulating SeY in liver metabolism and bird's health. Thus, the mRNA expression microarray, GSE25151, was downloaded from Gene Expression Omnibus (GEO) database. GSE25151 consists of liver samples from SeY-treated and the control broilers. Six hundred four differentially expressed genes (DEGs) were identified in livers between SeY-treated and control. Gene ontology (GO) enrichment analysis indicated that those DEGs are mainly involved in metabolism-related biological processes, such as biological regulation, molecular processes, responses to stimuli, cell communication and proliferation, and growth. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed the DEGs mainly enriched in metabolism-related signaling pathways, including PI3K, Akt, Wnt, calcium, IGF1 receptor, and MAPK signaling pathways. Moreover, many genes, such as NMUR1, NMU, and GPRC6A, might contribute to the regulation of SeY to broiler liver metabolism and health. In conclusion, the current study enhances our understanding of the regulation of SeY in liver metabolism and health of the birds and will assist studies of the molecular mechanisms of SeY regulation in chicken liver.

The regulatory role and mechanism of autophagy in energy metabolism-related hepatic fibrosis

Hepatic fibrosis is a key pathological process of chronic liver diseases, caused by alcohol, toxic and aberrant energy metabolism. It progresses to cirrhosis or even hepatic carcinoma without effective treatment. Studies have shown that autophagy has important regulatory effects on hepatic stellate cells (HSCs) energy metabolism, and then affect the activation state of HSCs. Autophagy maintains hepatic energy homeostasis, and the dysregulation of autophagy can lead to the activation of HSCs and the occurrence and development of hepatic fibrosis. It is necessary to explore the mechanism of autophagy in energy metabolism-related hepatic fibrosis. Herein, the current study summarizes the regulating mechanisms of autophagy through different targets and signal pathways in energy metabolism-related hepatic fibrosis, and discusses the regulatory effect of autophagy by natural plant-derived, endogenous and synthetic compounds for the treatment of hepatic fibrosis. A better comprehension of autophagy in hepatic stellate cells energy metabolism-related hepatic fibrosis may provide effective intervention of hepatic fibrosis, explore the potential clinical strategies and promote the drug treatment of hepatic fibrosis.

Pathogenesis of Liver Fibrosis and Its TCM Therapeutic Perspectives

Liver fibrosis is a pathological process of abnormal tissue proliferation in the liver caused by various pathogenic factors, which will further develop into cirrhosis or even hepatocellular carcinoma if liver injury is not intervened in time. As a diffuse progressive liver disease, its clinical manifestations are mostly excessive deposition of collagen-rich extracellular matrix resulting in scar formation due to liver injury. Hepatic fibrosis can be caused by hepatitis B and C, fatty liver, alcohol, and rare diseases such as hemochromatosis. As the metabolic center of the body, the liver regulates various vital activities. During the development of fibrosis, it is influenced by many other factors in addition to the central event of hepatic stellate cell activation. Currently, with the increasing understanding of TCM, the advantages of TCM with multiple components, pathways, and targets have been demonstrated. In this review, we will describe the factors influencing liver fibrosis, focusing on the effects of cells, intestinal flora, iron death, signaling pathways, autophagy and angiogenesis on liver fibrosis, and the therapeutic effects of herbal medicine on liver fibrosis.

The Role of Catecholamines in Pathophysiological Liver Processes

Over the last few years, the number of research publications about the role of catecholamines (epinephrine, norepinephrine, and dopamine) in the development of liver diseases such as liver fibrosis, fatty liver diseases, or liver cancers is constantly increasing. However, the mechanisms involved in these effects are not well understood. In this review, we first recapitulate the way the liver is in contact with catecholamines and consider liver implications in their metabolism. A focus on the expression of the adrenergic and dopaminergic receptors by the liver cells is also discussed. Involvement of catecholamines in physiological (glucose metabolism, lipids metabolism, and liver regeneration) and pathophysiological (impact on drug-metabolizing enzymes expression, liver dysfunction during sepsis, fibrosis development, or liver fatty diseases and liver cancers) processes are then discussed. This review highlights the importance of understanding the mechanisms through which catecholamines influence liver functions in order to draw benefit from the adrenergic and dopaminergic antagonists currently marketed. Indeed, as these molecules are well-known drugs, their use as therapies or adjuvant treatments in several liver diseases could be facilitated.

Research progress on drugs targeting the TGF-β signaling pathway in fibrotic diseases

Tissue fibrosis is a key factor leading to disability and death worldwide; however, thus far, there are no approved treatments for fibrosis. Transforming growth factor (TGF)-β is a major pro-fibrotic cytokine, which is expected to become a target in the treatment of fibrosis; however, since TGF-β has a wide range of biological functions involving a variety of biological processes in the body, a slight change in TGF-β may have a systematic effect. Indiscriminate inhibition of TGF-β can lead to adverse reactions, which can affect the efficacy of treatment. Therefore, it has become very important to explore how both the TGF-β signaling pathway is inhibited and the safe and efficient TGF-β small molecule inhibitors or neutralizing antibodies are designed in the treatment of fibrotic diseases. In this review, we mainly discuss the key role of the TGF-β signaling pathway in fibrotic diseases, as well as the development of fibrotic drugs in recent years, and explore potential targets in the treatment of fibrotic diseases in order to guide subsequent drug development.

Resolving hepatic fibrosis via suppressing oxidative stress and an inflammatory response using a novel hyaluronic acid modified nanocomplex

Hepatic fibrosis remains a serious threat to human health globally and there are no effective antifibrotic pharmacotherapeutic strategies, to date. Upon the activation of hepatic stellate cells, excess deposition of the extracellular matrix occurs, acting as a trigger that generates reactive oxygen species and an inflammatory response, thereby exacerbating the development of hepatic fibrosis and inflammation. In this study, we incorporated an idea that targets key pathways for developing novel anti-fibrosis nanomedicine. Previous studies have reported the potential of LY294002 (LY) as a PI3K/Akt inhibitor that suppresses the HSC activation and fibrosis development; however, its poor water solubility impedes further investigation. Moreover, the proliferation of HSC, severe oxidative stress and inflammatory conditions could be undermined by oridonin (ORD) treatment. Herein, we developed an HA-ORD/LY-Lips nanocomplex, where LY294002 was encapsulated into liposomes to prepare LY-Lips while ORD was conjugated with a hyaluronic acid (HA) polymer acting as a prodrug HA-ORD. The complex exerts great potential in improving the liver-targeted drug release. We adopted a series of in vitro and in vivo evaluations which demonstrate that HA-ORD/LY-Lips can significantly avert activation of hepatic stellate cells via scavenging reactive oxygen species and suppressing an inflammatory response. Our work implements a proof of concept strategy for fibrosis treatment based on the dual antioxidative and anti-inflammatory mechanisms, which may be applicable to treat liver fibrosis associated with a dysregulated inflammatory microenvironment.