Proliferation Of Hepatic Stellate Cells Research Articles

Hepatic recruitment of myeloid-derived suppressor cells upon liver injury promotes both liver regeneration and fibrosis

BackgroundThe liver regeneration is a highly complicated process depending on the close cooperations between the hepatocytes and non-parenchymal cells involving various inflammatory cells. Here, we explored the role of myeloid-derived suppressor cells (MDSCs) in the processes of liver regeneration and liver fibrosis after liver injury.MethodsWe established four liver injury models of mice including CCl4-induced liver injury model, bile duct ligation (BDL) model, concanavalin A (Con A)-induced hepatitis model, and lipopolysaccharide (LPS)-induced hepatitis model. The intrahepatic levels of MDSCs (CD11b+Gr-1+) after the liver injury were detected by flow cytometry. The effects of MDSCs on liver tissues were analyzed in the transwell co-culture system, in which the MDSCs cytokines including IL-10, VEGF, and TGF-β were measured by ELISA assay and followed by being blocked with specific antibodies.ResultsThe intrahepatic infiltrations of MDSCs with surface marker of CD11b+Gr-1+ remarkably increased after the establishment of four liver injury models. The blood served as the primary reservoir for hepatic recruitment of MDSCs during the liver injury, while the bone marrow appeared play a compensated role in increasing the number of MDSCs at the late stage of the inflammation. The recruited MDSCs in injured liver were mainly the M-MDSCs (CD11b+Ly6G−Ly6Chigh) featured by high expression levels of cytokines including IL-10, VEGF, and TGF-β. Co-culture of the liver tissues with MDSCs significantly promoted the proliferation of both hepatocytes and hepatic stellate cells (HSCs).ConclusionsThe dramatically and quickly infiltrated CD11b+Gr-1+ MDSCs in injured liver not only exerted pro-proliferative effects on hepatocytes, but also accounted for the activation of profibrotic HSCs.

Novel Inositol 1,4,5-Trisphosphate Receptor Inhibitor Antagonizes Hepatic Stellate Cell Activation: A Potential Drug to Treat Liver Fibrosis.

Liver fibrosis, characterized by excessive extracellular matrix (ECM) deposition, can progress to cirrhosis and increases the risk of liver cancer. Hepatic stellate cells (HSCs) play a pivotal role in fibrosis progression, transitioning from a quiescent to activated state upon liver injury, wherein they proliferate, migrate, and produce ECM. Calcium signaling, involving the inositol 1,4,5-trisphosphate receptor (IP3R), regulates HSC activation. This study investigated the efficacy of a novel IP3R inhibitor, desmethylxestospongin B (dmXeB), in preventing HSC activation. Freshly isolated rat HSCs were activated in vitro in the presence of varying dmXeB concentrations. The dmXeB effectively inhibited HSC proliferation, migration, and expression of fibrosis markers without toxicity to the primary rat hepatocytes or human liver organoids. Furthermore, dmXeB preserved the quiescent phenotype of HSCs marked by retained vitamin A storage. Mechanistically, dmXeB suppressed mitochondrial respiration in activated HSCs while enhancing glycolytic activity. Notably, methyl pyruvate, dimethyl α-ketoglutarate, and nucleoside supplementation all individually restored HSC proliferation despite dmXeB treatment. Overall, dmXeB demonstrates promising anti-fibrotic effects by inhibiting HSC activation via IP3R antagonism without adverse effects on other liver cells. These findings highlight dmXeB as a potential therapeutic agent for liver fibrosis treatment, offering a targeted approach to mitigate liver fibrosis progression and its associated complications.

TM7SF3 controls TEAD1 splicing to prevent MASH-induced liver fibrosis

The mechanisms of hepatic stellate cell (HSC) activation and the development of liver fibrosis are not fully understood. Here, we show that deletion of a nuclear seven transmembrane protein, TM7SF3, accelerates HSC activation in liver organoids, primary human HSCs, and invivo in metabolic-dysfunction-associated steatohepatitis (MASH) mice, leading to activation of the fibrogenic program and HSC proliferation. Thus, TM7SF3 knockdown promotes alternative splicing of the Hippo pathway transcription factor, TEAD1, by inhibiting the splicing factor heterogeneous nuclear ribonucleoprotein U (hnRNPU). This results in the exclusion of the inhibitory exon 5, generating a more active form of TEAD1 and triggering HSC activation. Furthermore, inhibiting TEAD1 alternative splicing with a specific antisense oligomer (ASO) deactivates HSCs invitro and reduces MASH diet-induced liver fibrosis. In conclusion, by inhibiting TEAD1 alternative splicing, TM7SF3 plays a pivotal role in mitigating HSC activation and the progression of MASH-related fibrosis.

DCDC2 inhibits hepatic stellate cell activation and ameliorates CCl4-induced liver fibrosis by suppressing Wnt/β-catenin signaling

Liver fibrosis, as a consequence of chronic liver disease, involves the activation of hepatic stellate cell (HSC) caused by various chronic liver injuries. Emerging evidence suggests that activation of HSC during an inflammatory state can lead to abnormal accumulation of extracellular matrix (ECM). Investigating novel strategies to inhibit HSC activation and proliferation holds significant importance for the treatment of liver fibrosis. As a member of the doublecortin domain-containing family, doublecortin domain containing 2 (DCDC2) mutations can lead to neonatal sclerosing cholangitis, but its involvement in liver fibrosis remains unclear. Therefore, this study aims to elucidate the role of DCDC2 in liver fibrosis. Our findings revealed a reduction in DCDC2 expression in both human fibrotic liver tissues and carbon tetrachloride (CCl4)-induced mouse liver fibrotic tissues. Furthermore, exposure to transforming growth factor beta-1(TGF-β1) stimulation resulted in a dose- and time-dependent decrease in DCDC2 expression. The overexpression of DCDC2 inhibited the expression of α-smooth muscle actin (α-SMA) and type I collagen alpha 1 (Col1α1), and reduced the activation of HSC stimulated with TGF-β1. Additionally, we provided evidence that the Wnt/β-catenin signaling pathway was involved in this process, wherein DCDC2 was observed to inhibit β-catenin activation, thereby preventing its nuclear translocation. Furthermore, our findings demonstrated that DCDC2 could attenuate the proliferation and epithelial-mesenchymal transition (EMT)-like processes of HSC. In vivo, exogenous DCDC2 could ameliorate CCl4-induced liver fibrosis. In summary, DCDC2 was remarkably downregulated in liver fibrotic tissues of both humans and mice, as well as in TGF-β1-activated HSC. DCDC2 inhibited the activation of HSC induced by TGF-β1 in vitro and fibrogenic changes in vivo, suggesting that it is a promising therapeutic target for liver fibrosis and warrants further investigation in clinical practice.

Plant-derived flavonoids are a potential source of drugs for the treatment of liver fibrosis.

Liver fibrosis is a dynamic pathological process that can be triggered by any chronic liver injury. If left unaddressed, it will inevitably progress to the severe outcomes of liver cirrhosis or even hepatocellular carcinoma. In the past few years, the prevalence and fatality of hepatic fibrosis have been steadily rising on a global scale. As a result of its intricate pathogenesis, the quest for pharmacological interventions targeting liver fibrosis has remained a formidable challenge. Currently, no pharmaceuticals are exhibiting substantial clinical efficacy in the management of hepatic fibrosis. Hence, it is of utmost importance to expedite the development of novel therapeutics for the treatment of this condition. Various research studies have revealed the ability of different natural flavonoid compounds to alleviate or reverse hepatic fibrosis through a range of mechanisms, which are related to the regulation of liver inflammation, oxidative stress, synthesis and secretion of fibrosis-related factors, hepatic stellate cells activation, and proliferation, and extracellular matrix synthesis and degradation by these compounds. This review summarizes the progress of research on different sources of natural flavonoids with inhibitory effects on liver fibrosis over the last decades. The anti-fibrotic effects of natural flavonoids have been increasingly studied, making them a potential source of drugs for the treatment of liver fibrosis due to their good efficacy and biosafety.

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

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. 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. 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.

Cordycepin alleviates hepatic fibrosis in association with the inhibition of glutaminolysis to promote hepatic stellate cell senescence

Cordycepin (CRD) is an active component derived from Cordyceps militaris, which possesses multiple biological activities and uses in liver disease. However, whether CRD improves liver fibrosis by regulating hepatic stellate cell (HSC) activation has remained unknown. The study aims further to clarify the activities of CRD on liver fibrosis and elucidate the possible mechanism. Our results demonstrated that CRD significantly relieved hepatocyte injury and inhibited HSC activation, alleviating hepatic fibrogenesis in the Diethyl 1,4-dihydro-2,4,6-trimethyl-3,5-pyridinedicarboxylate (DDC)-induced mice model. In vitro, CRD exhibited dose-dependent repress effects on HSC proliferation, migration, and pro-fibrotic function in TGF-β1-activated LX-2 and JS-1 cells. The functional enrichment analysis of RNA-seq data indicated that the pathway through which CRD alleviates HSC activation involves cellular senescence and cell cycle-related pathways. Furthermore, it was observed that CRD accumulated the number of senescence-associated a-galactosidase positive cells and the levels of senescencemarker p21, and provoked S phasearrestof activated HSC. Remarkably, CRD treatment abolished TGF-β‐induced yes-associated protein (YAP) nuclear translocation that acts upstream of glutaminolysis in activated HSC. On the whole, CRD significantly inhibited glutaminolysis of activated-HSC and induced cell senescence through the YAP signaling pathway, consequently alleviating liver fibrosis, which may be a valuable supplement for treating liver fibrosis.

Mechanism of acacetin regulating hepatic stellate cell apoptosis based on network pharmacology and experimental verification

BackgroundHepatic fibrosis is caused by various liver diseases and eventually develops into liver cancer. There is no specific drug approved for the treatment of hepatic fibrosis in the world. Acacetin (AC), a natural flavonoid, is widely present in nature in various plants, such as black locust, Damiana, Silver birch. It has been reported that acacetin can inhibit the proliferation of cancer cells and induce apoptosis. PurposeIn this study, we investigated the effect of acacetin on hepatic stellate cell apoptosis, thereby improving hepatic fibrosis, and combined experimental validation and molecular docking to reveal the underlying mechanism. ResultFirst, we discovered that acacetin inhibited hepatic stellate cell proliferation as well as the expression of fibrosis-related proteins α-smooth muscle actin (α-SMA) and collagen type I 1 gene (COL1A1) in LX2 cells. Acacetin was then found to promote apoptosis of hepatic stellate cells through the caspase cascade pathway. Network pharmacology screening showed that TP53, CASP3, CASP8, BCL2, PARP1, and BAX were the most important targets related to apoptosis in the PPI network. GO and KEGG analyses of these six important targets were performed, and the top 10 enriched biological processes and related signaling pathways were revealed. Further network pharmacology analysis proved that apoptosis was involved in the biological process of acacetin's action against hepatic stellate cells. Finally, molecular docking revealed that acacetin binds to the active sites of six apoptotic targets. In vitro experiments further confirmed that acacetin could promote the apoptosis of LX2 cells by inducing the activation of P53, thereby improving hepatic fibrosis. Conclusionacacetin induces P53 activation and promotes apoptosis of hepatic stellate cells thereby ameliorating hepatic fibrosis.

Dual neovascular targets of vascular endothelial growth factor receptors and platelet‐derived growth factor receptor ameliorate thioacetamide induced liver fibrosis in rats

AbstractAimsNeovascularization plays a crucial role in liver fibrosis (LF), and blocking vascular endothelial growth factor receptors (VEGFR) has been shown to improve fibrosis. The aim of our study was to investigate the role of dual neovascularization targets, VEGFR, and platelet‐derived growth factor receptor (PDGFR), in ameliorating fibrosis.MethodsIn vitro, we observed the effects of apatinib (APA) (a VEGFR inhibitor) and donafenib (DON) (a VEGFR and PDGFR inhibitor) on the activation, proliferation, and apoptosis of hepatic stellate cells (HSCs) from rats and humans. In vivo, we established a thioacetamide (TAA)‐induced liver fibrosis rat model to explore the antifibrosis effect of APA and DON. We used the method of random table to randomly divide the rats into 4 groups. We detected the expression of angiogenesis‐related proteins using Western blot and immunohistochemistry.ResultsAPA and DON inhibited the proliferation and activation of HSCs, promoted apoptosis of HSCs, and arrested the S phase of the cell cycle in vitro. We also found that DON had a stronger inhibitory effect on HSCs. In vivo, APA and DON ameliorated liver fibrosis, reduced collagen deposition and α‐SMA expression in rats, and DON had a stronger improvement effect. APA and DON downregulated the expression of VEGFR2 while inhibiting the phosphorylation of Akt and ERK1/2. DON can act through both VEGF and PDGF pathways, whereas APA can only act through the VEGF pathway.ConclusionAntiangiogenesis is a promising approach for the treatment of fibrosis. Compared with a single‐target drug (APA), the dual‐target drug (DON) can achieve better therapeutic effects.

Caffeine in Hepatocellular Carcinoma: Cellular Assays, Animal Experiments, and Epidemiological Investigation.

The use of caffeine in treating various liver diseases has made substantial progress in the past decade owing to advances in science, technology, and medicine. However, whether caffeine has a preventive effect on hepatocellular carcinoma (HCC) and its mechanism are still worth further investigation. In this review, we summarize and analyze the efficacy and safety of caffeine in the prevention of HCC. We conducted a review of articles published in PubMed and Web of Science in the past 2 decades until December 6, 2023, which were searched for using the terms "Caffeine" and "Hepatocellular Carcinoma." Studies have found that coffee intake is negatively correlated with HCC risk, especially caffeinated coffee. Recent studies have found that caffeine has beneficial effects on liver health, decreasing levels of enzymes responsible for liver damaging and slowing the progression of hepatic fibrosis and cirrhosis. Caffeine also acts against liver fibrosis through adenosine receptors (ARs), which promote tissue remodeling by inducing fibrin and collagen production. Additionally, new studies have found that moderate consumption of caffeinated beverages can decrease various the levels of various collagens in patients with chronic hepatitis C. Furthermore, polyphenolic compounds in coffee can improve fat homeostasis, reduce oxidative stress, and prevent liver steatosis and fibrosis. Moreover, many in vitro studies have shown that caffeine can protect liver cells and inhibit the activation and proliferation of hepatic stellate cells. Taken together, we describe the benefits of caffeine for liver health and highlight its potential values as a drug to prevent various hepatic diseases. As a protective agent of liver inflammation, non-selective AR inhibitor caffeine can inhibit the growth of HCC cells by inhibiting adenosine and AR binding to initiate immune response, providing a basis for the future development of caffeine as an adjuvant drug against HCC.

Mitochondria-targeted reactive oxygen species blockor SS-31 blocks hepatic stellate cell activation and alleviates hepatic fibrosis by regulating NLRP3 inflammasomes.

This study aimed to elucidate the effect of mitochondria-targeted reactive oxygen species (ROS) blockor SS-31 on hepatic stellate cells (HSC) activation during liver fibrosis. TGF-β1 was employed to induce HSC activation, while MitoSOX Red was utilized to assess the presence of mitochondrial ROS. The mitochondrial membrane potential (MMP) was measured using the JC-1 probe, and the ATP level was determined using a specific kit. The proliferation of HSCs was assessed using CCK-8 and colony formation assays, whereas flow cytometry was employed to detect HSC apoptosis. Fibrotic markers (COL1A1 and α-SMA) and NLRP3 inflammasome components (NLRP3, caspase-1, and ASC) were analyzed via Western blotting. Liver fibrosis was induced in mice using CCl4, and subsequently, histopathological changes were observed through HE staining and Masson staining. In TGF-β1-activated HSCs, mitochondrial ROS expression increased, MMP and ATP content decreased, indicating mitochondrial damage. After TGF-β1 induction, HSC proliferation increased, apoptosis decreased, and COL1A1, α-SMA, and NLRP3 inflammasome protein expression increased. After SS-31 treatment, mitochondrial ROS expression decreased, MMP recovered, ATP level increased, HSC proliferation decreased, apoptosis increased, and the expressions of COL1A1, α-SMA, and NLRP3 inflammasome decreased. NLRP3 blockor MCC950 treatment blocked HSC activation. CCL4-induced liver fibrosis mice had inflammatory cell infiltration and significant collagen fiber deposition in the liver. After SS-31 treatment, liver inflammation and collagen deposition were significantly reduced. SS-31, as a mitochondria-targeted ROS blockor, can block HSC activation by regulating the NLRP3 inflammasome, thereby alleviating liver fibrosis.

An integrated investigation of sulfotransferases (SULTs) in hepatocellular carcinoma and identification of the role of SULT2A1 on stemness.

The cytosolic sulfotransferases (SULTs) are phase II conjugating enzymes, which are widely expressed in the liver and mainly mediate the sulfation of numerous xenobiotics and endogenous compounds. However, the role of various SULTs genes has not been reported in hepatocellular carcinoma (HCC). This study aims to analyze the expression and potential functional roles of SULTs genes in HCC and to identify the role of SULT2A1 in HCC stemness as well as the possible mechanism. We found that all of the 12 SULTs genes were differentially expressed in HCC. Moreover, clinicopathological features and survival rates were also investigated. Multivariate regression analysis showed that SULT2A1 and SULT1C2 could be used as independent prognostic factors in HCC. SULT1C4, SULT1E1, and SULT2A1 were significantly associated with immune infiltration. SULT2A1 deficiency in HCC promoted chemotherapy resistance and stemness maintenance. Mechanistically, silencing of SULT2A1 activated the AKT signaling pathway, on the one hand, promoted the expression of downstream stemness gene c-Myc, on the other hand, facilitated the NRF2 expression to reduce the accumulation of ROS, and jointly increased HCC stemness. Moreover, knockdown NR1I3 was involved in the transcriptional regulation of SULT2A1 in stemness maintenance. In addition, SULT2A1 knockdown HCC cells promoted the proliferation and activation of hepatic stellate cells (HSCs), thereby exerting a potential stroma remodeling effect. Our study revealed the expression and role of SULTs genes in HCC and identified the contribution of SULT2A1 to the initiation and progression of HCC.

Synergistic Hepatoprotective Effects of Mesenchymal Stem Cells and Platelet-Rich Plasma in a Rat Model of Bile Duct Ligation-Induced Liver Cirrhosis.

Liver cirrhosis poses a global health challenge marked by significant prevalence and mortality. Current therapeutic options are limited by high costs and immune-mediated rejection, necessitating the exploration of innovative strategies to enhance hepatic self-rehabilitation, and counteract the underlying pathological mechanisms. We evaluated the hepatoprotective activity of rat adipose-derived mesenchymal stem cells (ADMSCs) in combination with platelet-rich plasma (PRP) and recombinant human hepatocyte growth factor (rh-HGF) on a rat model of liver fibrosis/cirrhosis induced by bile duct ligation (BDL). Treatment with PRP or rh-HGF alone did not yield significant hepatoprotection in the BDL-induced liver cirrhosis model. However, ADMSC transplantation alone exhibited the potential to alleviate impaired liver conditions. The combination of PRP and rh-HGF demonstrated superior ameliorative effects compared to either treatment alone. Notably, the combination of ADMSC + PRP or ADMSC + rh-HGF significantly enhanced hepatoprotective capacity compared to individual or combined PRP and rh-HGF therapies. Injection of ADMSC via the tail vein reduced inflammation, hepatocyte damage, and collagen deposition, improving overall liver function. This improvement was more pronounced when ADMSC was administered with PRP and rh-HGF versus monotherapy. Our study concludes that ADMSCs exert antifibrotic effects by inhibiting hepatic stellate cell proliferation, collagen synthesis, and inducing apoptosis. ADMSCs also demonstrate immune-modulatory effects and transdifferentiate into hepatic progenitor cells, secreting trophic factors, cytokines, and chemokines that promote impaired liver regeneration. The observed arrest in liver fibrosis progression highlights the potential therapeutic impact of these interventions.

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.

Echinacoside Exerts Antihepatic Fibrosis Effects in High-Fat Mice Model by Modulating the ACVR2A-Smad Pathway.

Nonalcoholic steatohepatitis (NASH) is an increasingly common chronic liver disease in which hepatic fibrosis is the major pathological change. The transforming growth factor β (TGF-β)/mall mothers against decapentaplegic (Smad) signaling is the main effector of fibrosis. Although the antifibrotic effect of echinacoside (Ech) on the liver has been indicated previously, the cellular and molecular mechanisms remain unclear. This study aims to investigate both in vivo and in vitro antifibrotic properties of Ech. Cell viability and scratch/wound assays show that Ech significantly inhibits the proliferation, migration, and activation of human hepatic stellate LX-2 cells. In mice with high-fat diet-induced hepatic fibrosis, Ech treatment attenuates the progression of liver injury, inflammation, and fibrosis. Furthermore, transcriptome analysis and subsequent functional validation demonstrate that Ech achieves antifibrotic effects by the activin receptor type-2A (ACVR2A)-mediated TGF-β1/Smad signaling pathway; ultimately, ACVR2A is demonstrated to be an important target for hepatic fibrosis by inhibiting and inducing the expression of ACVR2A in LX-2 cells. Ech exerts potent antifibrotic effects by inhibiting the ACVR2A-mediated TGF-β1/Smad signaling axis and may serve as an alternative treatment for hepatic fibrosis.

Antioxidative Hyaluronic Acid-Bilirubin Nanomedicine Targeting Activated Hepatic Stellate Cells for Anti-Hepatic-Fibrosis Therapy.

Liver fibrosis is a life-threatening and irreversible disease. The fibrosis process is largely driven by hepatic stellate cells (HSCs), which undergo transdifferentiation from an inactivated state to an activated one during persistent liver damage. This activated state is responsible for collagen deposition in liver tissue and is accompanied by increased CD44 expression on the surfaces of HSCs and amplified intracellular oxidative stress, which contributes to the fibrosis process. To address this problem, we have developed a strategy that combines CD44-targeting of activated HSCs with an antioxidative approach. We developed hyaluronic acid-bilirubin nanoparticles (HABNs), composed of endogenous bilirubin, an antioxidant and anti-inflammatory bile acid, and hyaluronic acid, an endogenous CD44-targeting glycosaminoglycan biopolymer. Our findings demonstrate that intravenously administered HABNs effectively targeted the liver, particularly activated HSCs, in fibrotic mice with choline-deficient l-amino acid-defined high-fat diet (CD-HFD)-induced nonalcoholic steatohepatitis (NASH). HABNs were able to inhibit HSC activation and proliferation and collagen production. Furthermore, in a murine CD-HFD-induced NASH fibrosis model, intravenously administered HABNs showed potent fibrotic modulation activity. Our study suggests that HABNs have the potential to serve as a targeted anti-hepatic-fibrosis therapy by modulating activated HSCs via CD44-targeting and antioxidant strategies. This strategy could also be applied to various ROS-related diseases in which CD44-overexpressing cells play a pivotal role.

Therapeutic Potential of Benzimidazoisoquinoline Derivatives in Alleviating Murine Hepatic Fibrosis.

Short Title: Benzimidazoisoquinoline derivatives as potent antifibrotics Hepatic fibrosis is a pathological condition of liver disease with an increasing number of cases worldwide. Therapeutic strategies are warranted to target the activated hepatic stellate cells (HSCs), the collagen-producing cells, an effective strategy for controlling the disease progression. Benzimidazoisoquinoline derivatives were synthesized as hybrid molecules by the combination of benzimidazoles and isoquinolines to evaluate their anti-fibrotic potential using an in-vitro and in-vivo model of hepatic fibrosis. A small library of benzimidazoisoquinoline derivatives (1-17 and 18-21) was synthesized from 2-aryl benzimidazole and acetylene functionalities through C-H and N-H activation. Compounds (10 and its recently synthesized derivatives 18-21) depicted a significant decrease in PDGF-BB and/or TGFβ-induced proliferation (1.7-1.9 -fold), migration (3.5-5.0 -fold), and fibrosis-related gene expressions in HSCs. These compounds could revert the hepatic damage caused by chronic exposure to hepatotoxicants, ethanol, and/or carbon tetrachloride as evident from the histological, biochemical, and molecular analysis. Anti-fibrotic effect of the compounds was supported by the decrease in the malondialdehyde level, collagen deposition, and gene expression levels of fibrosis-related markers such as α-SMA, COL1α1, PDGFRβ, and TGFRIIβ in the preclinical models of hepatic fibrosis. In conclusion, the synthesized benzimidazoisoquinoline derivatives (compounds 18, 19, 20, and 21) possess anti-fibrotic therapeutic potential against liver fibrosis.

Angiotensin II type-2 receptor attenuates liver fibrosis progression by suppressing IRE1α-XBP1 pathway.

The renin-angiotensin system (RAS) has been recognized as a crucial contributor to the development of liver fibrosis, and AT2R, an essential component of RAS, is involved in the progression of liver fibrosis. However, the underlying mechanisms by which AT2R modulates liver fibrosis remain elusive. Here, we report that AT2R was induced to be highly expressed during the progression of liver fibrosis, and the elevated AT2R attenuates liver fibrosis by suppressing IRE1α-XBP1 pathway. In this study, we found that AT2R is not expressed in the no cirrhotic adult liver, but is induced expression during liver fibrosis in both cirrhotic patients and fibrotic mice models. Upregulated AT2R inhibits the activation and proliferation of hepatic stellate cells (HSCs). In addition, our study showed that during liver fibrosis, AT2R deletion increased the dimerization activation of IRE1α and promoted XBP1 splicing, and the spliced XBP1s could promote their transcription by binding to the AT2R promoter and repress the IRE1α-XBP1 axis, forming an AT2R-IRE1α-XBP1 negative feedback loop. Importantly, the combination treatment of an AT2R agonist and an endoplasmic reticulum stress (ER stress) alleviator significantly attenuated liver fibrosis in a mouse model of liver fibrosis. Therefore, we conclude that the AT2R-IRE1α signaling pathway can regulate the progression of liver fibrosis, and AT2R is a new potential therapeutic target for treating liver fibrosis.

Pioneering PGC-1α-boosted secretome: a novel approach to combating liver fibrosis.

Liver fibrosis is a critical health issue with limited treatment options. This study investigates the potential of PGC-Sec, a secretome derived from peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)-overexpressing adipose-derived stem cells (ASCs), as a novel therapeutic strategy for liver fibrosis. Upon achieving a cellular confluence of 70%-80%, ASCs were transfected with pcDNA-PGC-1α. PGC-Sec, obtained through concentration of conditioned media using ultrafiltration units with a 3-kDa cutoff, was assessed through in vitro assays and in vitro mouse models. In vitro, PGC-Sec significantly reduced LX2 human hepatic stellate cell proliferation and mitigated mitochondrial oxidative stress compared to the control-secretome. In an in vivo mouse model, PGC-Sec treatment led to notable reductions in hepatic enzyme activity, serum proinflammatory cytokine concentrations, and fibrosis-related marker expression. Histological analysis demonstrated improved liver histology and reduced fibrosis severity in PGC-Sec-treated mice. Immunohistochemical staining confirmed enhanced expression of PGC-1α, optic atrophy 1 (a mitochondrial function marker), and peroxisome proliferator-activated receptor alpha (an antifibrogenic marker) in the PGC-Sec-treated group, along with reduced collagen type 1A expression (a profibrogenic marker). These findings highlight the therapeutic potential of PGC-Sec in combating liver fibrosis by enhancing mitochondrial biogenesis and function, and promoting antifibrotic processes. PGC-Sec holds promise as a novel treatment strategy for liver fibrosis.

Th2 Cell Activation in Chronic Liver Disease Is Driven by Local IL33 and Contributes to IL13-Dependent Fibrogenesis

Type 2 immune responses contribute to liver fibrosis in parasite infections, but their role in other liver diseases is less well understood. Here, we aimed at unravelling mechanisms involved in T helper 2 (Th2) T-cell polarization, activation, and recruitment in human liver fibrosis and cirrhosis. Tissues, cells, and serum from human livers were analyzed using quantitative reverse-transcription polymerase chain reaction, enzyme-linked immunosorbent assay, fluorescence in situ hybridization, immunostaining, flow cytometry, and various functional invitro assays. Cellular interactions and soluble mediators involved in T-cell polarization and recruitment were studied, as well as their effect on hepatic stellate cell (HSC) activation, proliferation, and extracellular matrix synthesis. In human liver fibrosis, a stage-dependent increase in Th2-related transcription factors, Th2 cytokines, and trans-acting T-cell-specific transcription factor-expressing T cells was observed, and was highest in cirrhotic livers. The alarmin interleukin (IL)33 was found to be increased in livers and sera from patients with cirrhosis, to act as a chemotactic agent for Th2 cells, and to induce type 2 polarization of CD4+ T cells. Oval cells, liver sinusoidal endothelial cells, intrahepatic macrophages, and migrating monocytes were identified as sources of IL33. IL33-activated T cells, but not IL33 alone, induced HSC activation, as shown by Ki67 and α-smooth muscle actin staining, increased collagen type I alpha 1 chain messenger RNA expression, and wound healing assays. The profibrotic effect of IL33-activated T cells was contact-independent and could be antagonized using monoclonal antibodies against IL13. In patients with chronic liver disease, the alarmin IL33 promotes the recruitment and activation of CD4+ T cells with Th2-like properties, which activate paracrine HSC in an IL13-dependent manner and promotes fibrogenesis.