Oxidative stress promotes liver fibrosis by modulating the microRNA-144 and SIN3A-p38 pathways in hepatic stellate cells.

Background & Aims: Reactive oxygen species (ROS) act as modulators triggering cellular dysfunctions and organ damage including liver fibrosis in which hepatic stellate cell (HSC) activation plays a key role. Previous studies suggest that microRNA-144 (miR-144) acts as a pro-oxidant molecule; however, whether and how miR-144 affects HSC activation and liver fibrosis remain unknown. Methods: Carbon tetrachloride (CCl4) and bile duct ligation (BDL)-induced experimental liver fibrosis models were used. Hepatic miR-144 expression was analyzed by miRNA in situ hybridization with RNAscope probe. The in vivo effects of silencing or overexpressing miR-144 were examined with an adeno-associated virus 6 (AAV6) carrying miR-144 inhibitor or mimics in fibrotic mouse experimental models. Results: In this study, we demonstrated that ROS treatment significantly upregulated miR-144 in HSCs, which further promoted HSC activation in vitro. Interestingly, miR-144 was preferentially elevated in HSCs of experimental liver fibrosis in mice and in human liver fibrotic tissues. Furthermore, in vivo loss or gain-of-function experiments via AAV6 carrying miR-144 antagomir or agomir revealed that blockade of miR-144 in HSCs mitigated, while overexpression of miR-144 in HSCs accelerated the development of experimental liver fibrosis. Mechanistically, SIN3 transcription regulator family member A (SIN3A), a transcriptional repressor, was identified to be the target of miR-144 in HSCs. MiR-144 downregulated Sin3A, and in line with this result, specific knockdown of Sin3a in HSCs remarkedly activated p38 MAPK signaling pathway to promote HSC activation, eventually exacerbating liver fibrosis. Conclusions: Oxidative stress-driven miR-144 fuels HSC activation and liver fibrogenesis by limiting the SIN3A-p38 axis. Thus, a specific inhibition of miR-144 in HSCs could be a novel therapeutic strategy for the treatment of liver fibrosis.

Exportin 4 DNA promoter methylation in liver fibrosis.

A role for exportin 4 (XPO4) in the pathogenesis of liver fibrosis was recently identified. We sought to determine changes in hepatic XPO4 promoter methylation levels during liver fibrosis. The quantitative real-time RT-PCR technique was used to quantify the mRNA level of XPO4. Additionally, pyrosequencing was utilized to assess the promoter methylation status of XPO4. The methylation rate of the XPO4 promoter was significantly increased with fibrosis in human and mouse models, while XPO4 mRNA expression negatively correlated with methylation of its promoter. DNA methyltransferases (DNMTs) levels (enzymes that drive DNA methylation) were upregulated in patients with liver fibrosis compared to healthy controls and in hepatic stellate cells upon transforming growth factor beta (TGFß) stimulation. The DNA methylation inhibitor 5-Aza or specific siRNAs for these DNMTs led to restoration of XPO4 expression. The process of DNA methylation plays a crucial role in the repression of XPO4 transcription in the context of liver fibrosis development.

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.

Resmetirom, the long-awaited first treatment for metabolic dysfunction-associated steatohepatitis and liver fibrosis?

The most important factor associated with liver-related mortality in NAFLD is liver fibrosis. There is no approved treatment for metabolic dysfunction-associated steatohepatitis (MASH) or liver fibrosis. In the MAESTRO-NASH trial, Harrison et al.1 demonstrated the efficacy of resmetirom, a selective THR-ß agonist, for the treatment of MASH and liver fibrosis at 52 weeks.

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

BACKGROUND: The 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. METHODS: We 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-ß were measured by ELISA assay and followed by being blocked with specific antibodies. RESULTS: The 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-ß. Co-culture of the liver tissues with MDSCs significantly promoted the proliferation of both hepatocytes and hepatic stellate cells (HSCs). CONCLUSIONS: The 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.

Bystander Effects and Profibrotic Interactions in Hepatic Stellate Cells during HIV and HCV Coinfection.

This study aims to explore the influence of coinfection with HCV and HIV on hepatic fibrosis. A coculture system was set up to actively replicate both viruses, incorporating CD4 T lymphocytes (Jurkat), hepatic stellate cells (LX-2), and hepatocytes (Huh7.5). LX-2 cells' susceptibility to HIV infection was assessed through measurements of HIV receptor expression, exposure to cell-free virus, and cell-to-cell contact with HIV-infected Jurkat cells. The study evaluated profibrotic parameters, including programed cell death, ROS imbalance, cytokines (IL-6, TGF-ß, and TNF-α), and extracellular matrix components (collagen, α-SMA, and MMP-9). The impact of HCV infection on LX-2/HIV-Jurkat was examined using soluble factors released from HCV-infected hepatocytes. Despite LX-2 cells being nonsusceptible to direct HIV infection, bystander effects were observed, leading to increased oxidative stress and dysregulated profibrotic cytokine release. Coculture with HIV-infected Jurkat cells intensified hepatic fibrosis, redox imbalance, expression of profibrotic cytokines, and extracellular matrix production. Conversely, HCV-infected Huh7.5 cells exhibited elevated profibrotic gene transcriptions but without measurable effects on the LX-2/HIV-Jurkat coculture. This study highlights how HIV-infected lymphocytes worsen hepatic fibrosis during HCV/HIV coinfection. They increase oxidative stress, profibrotic cytokine levels, and extracellular matrix production in hepatic stellate cells through direct contact and soluble factors. These insights offer valuable potential therapies for coinfected individuals.

Expression of Fascin-1 and its diagnostic value in liver cancer.

Although some studies have reported on the expression and clinical significance of Fascin-1 (FSCN1) in liver cancer, the clinical application and differential diagnosis value of FSCN1 in liver cancer are still unclear. The aim of this study was to analyze the expression level of FSCN1 protein in liver cancer tissues and explore its diagnostic and application value in differentiating between hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). The immunehistochemical analysis was used to detect the expression of FSCN1 in 108 cases of HCC, 26 cases of ICC, 23 cases of liver cirrhosis, and 11 cases of normal liver tissues. The differences in the positive expression rate and strong positive expression rate of FSCN1 among different groups were analyzed. The positive rate of FSCN1 in normal liver tissues, liver cirrhosis, HCC, and ICC tissues was 0.0% (0/11), 0.0% (0/23), 13.9% (15/108), and 92.3% (24/26), respectively, while the strong positive rate was 0.0% (0/11), 0.0% (0/23), 0.9% (1/108), and 69.2% (18/26), respectively. Both the positive rate and strong positive rate of FSCN1 in ICC tissues were significantly higher than those in HCC, liver cirrhosis, and normal liver tissues. Additionally, the positive rate of FSCN1 in moderately to poorly differentiated HCC tissues was 18.8% (15/80), significantly higher than in well-differentiated HCC (0.0%, 0/28) (P = 0.031). In liver cancer, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FSCN1 positive prediction for ICC were 92.3%, 86.1%, 61.5%, and 97.9%, respectively, whereas the sensitivity, specificity, PPV, and NPV of FSCN1 strong positive prediction for ICC were 69.2%, 99.1%, 94.7%, and 93.0%, respectively. These results suggest that FSCN1 may play an important role in the occurrence and progression of liver cancer, and it can be used as a novel diagnostic marker for ICC.

[Arbutin ameliorates liver fibrosis in mice by inhibiting macrophage recruitment and regulating the Akt/NF-κB and Smad signaling pathways].

OBJECTIVE: To investigate the protective effect of arbutin against CCl4-induced hepatic fibrosis in mice and explore the underlying mechanisms. METHODS: Twenty-four C57BL/6 mice were randomly divided into control group, model group, and low- and high-dose arbutin treatment (25 and 50 mg/kg, respectively) groups. Mouse models of liver fibrosis were established by intraperitoneal injection of CCl4, and arbutin was administered daily via gavage for 6 weeks. After the treatments, serum biochemical parameters of the mice were tested, and liver tissues were taken for HE staining, Sirius Red staining and immunohistochemical staining. RT-qPCR was used to detect the mRNA levels of α-SMA, Pdgfb, Col1α1, Timp-1, Ccl2 and Tnf-a, and Western blotting was performed to detect α-SMA protein expression in the liver tissues. In the cell experiment, the effect of arbutin treatment for 24 h on THP-1 and RAW264.7 cell migration and recruitment was examined using Transwell migration assay and DAPI staining; The changes in protein levels of Akt, p65, Smad3, p-Akt, p-p65, p-Smad3 and α-SMA in arbutintreated LX-2 cells were detected with Western blotting. RESULTS: Arbutin treatment significantly lowered serum alanine aminotransferase and aspartate aminotransferase levels, alleviated liver tissue damage and collagen deposition, and reduced macrophage infiltration and α-SMA protein expression in the liver of the mouse models (P < 0.05 or 0.001). Arbutin treatment also significantly reduced CCl4-induced elevation of a-SMA, Pdgfb, Col1α1, Timp-1, Ccl2 and Tnf-a mRNA levels in mice (P < 0.05). In the cell experiment, arbutin treatment obviously inhibited migration and recruitment of THP-1 and RAW264.7 cells and lowered the phosphorylation levels of Akt, p65 and Smad3 and the protein expression level of α-SMA in LX-2 cells. CONCLUSION: Arbutin ameliorates liver inflammation and fibrosis in mice by inhibiting hepatic stellate cell activation via reducing macrophage recruitment and infiltration and suppressing activation of the Akt/NF-κB and Smad signaling pathways.

Fisetin ameliorates methotrexate induced liver fibrosis.

OBJECTIVE: Methotrexate (MTX), a widely used chemotherapeutic and immunosuppressive agent, is associated with hepatotoxicity, leading to liver fibrosis and cirrhosis. This study explores the regenerative and reparative effects of fisetin, a flavonoid with known antioxidant and anti-inflammatory properties, on MTX-induced liver fibrosis in a rat model. MATERIALS AND METHODS: Thirty-six male Wistar albino rats were divided into normal, MTX and saline, and MTX and fisetin. Liver injury was induced in the latter two groups using a single intraperitoneal dose of MTX (20 mg/kg). Fisetin (50 mg/kg/day) or saline was administered intraperitoneally for ten days. After sacrifice, liver tissues were subjected to histopathological evaluation and biochemical analyses, including Transforming Growth Factor-ß1 (TGF-beta), sirtuins-1 (SIRT-1), malondialdehyde (MDA), cytokeratin 18, thrombospondin 1, and alanine transaminase (ALT) levels. RESULTS: MTX administration significantly increased liver injury markers, including TGF-beta, MDA, cytokeratin 18, thrombospondin 1, and ALT, while reducing SIRT-1 levels. Fisetin treatment attenuated these effects, demonstrating its potential therapeutic impact. Histopathological analysis confirmed that fisetin mitigated MTX-induced hepatocyte necrosis, fibrosis, and cellular infiltration. CONCLUSIONS: This study proves that fisetin administration can alleviate MTX-induced liver damage in rats. The reduction in oxidative stress, inflammation, and apoptosis, along with the histological improvements, suggests fisetin's potential as a therapeutic agent against MTX-induced hepatotoxicity. Further investigations and clinical studies are warranted to validate these findings and assess fisetin's translational potential in human cases of MTX-induced liver damage.

Cannabidiol alleviates carbon tetrachloride-induced liver fibrosis in mice by regulating NF-κB and PPAR-α pathways.

Liver fibrosis has become a serious public health problem that can develop into liver cirrhosis and hepatocellular carcinoma and even lead to death. Cannabidiol (CBD), which is an abundant nonpsychoactive component in the cannabis plant, exerts cytoprotective effects in many diseases and under pathological conditions. In our previous studies, CBD significantly attenuated liver injury induced by chronic and binge alcohol in a mouse model and oxidative bursts in human neutrophils. However, the effects of CBD on liver fibrosis and the underlying mechanisms still need to be further explored. A mouse liver fibrosis model was induced by carbon tetrachloride (CCl4) for 10 weeks and used to explore the protective properties of CBD and related molecular mechanisms. After the injection protocol, serum samples and livers were used for molecular biology, biochemical and pathological analyses. The results showed that CBD could effectively improve liver function and reduce liver damage and liver fibrosis progression in mice; the expression levels of transaminase and fibrotic markers were reduced, and histopathological characteristics were improved. Moreover, CBD inhibited the levels of inflammatory cytokines and reduced the protein expression levels of p-NF-κB, NF-κB, p-IκBα, p-p38 MAPK, and COX-2 but increased the expression level of PPAR-α. We found that CBD-mediated protection involves inhibiting NF-κB and activating PPAR-α. In conclusion, these results suggest that the hepatoprotective effects of CBD may be due to suppressing the inflammatory response in CCl4-induced mice and that the NF-κB and PPAR-α signaling pathways might be involved in this process.

Selective Targeting of α4ß7/MAdCAM-1 Axis Suppresses Fibrosis Progression by Reducing Proinflammatory T Cell Recruitment to the Liver.

Integrin α4ß7+ T cells perpetuate tissue injury in chronic inflammatory diseases, yet their role in hepatic fibrosis progression remains poorly understood. Here, we report increased accumulation of α4ß7+ T cells in the liver of people with cirrhosis relative to disease controls. Similarly, hepatic fibrosis in the established mouse model of CCl4-induced liver fibrosis was associated with enrichment of intrahepatic α4ß7+ CD4 and CD8 T cells. Monoclonal antibody (mAb)-mediated blockade of α4ß7 or its ligand mucosal addressin cell adhesion molecule (MAdCAM)-1 attenuated hepatic inflammation and prevented fibrosis progression in CCl4-treated mice. Improvement in liver fibrosis was associated with a significant decrease in the infiltration of α4ß7+ CD4 and CD8 T cells, suggesting that α4ß7/MAdCAM-1 axis regulates both CD4 and CD8 T cell recruitment to the fibrotic liver, and α4ß7+ T cells promote hepatic fibrosis progression. Analysis of hepatic α4ß7+ and α4ß7- CD4 T cells revealed that α4ß7+ CD4 T cells were enriched for markers of activation and proliferation, demonstrating an effector phenotype. The findings suggest that α4ß7+ T cells play a critical role in promoting hepatic fibrosis progression, and mAb-mediated blockade of α4ß7 or MAdCAM-1 represents a promising therapeutic strategy for slowing hepatic fibrosis progression in chronic liver diseases.

Effects of Mesenchymal Stem Cells-Derived Extracellular Vesicles on Inhibition of Hepatic Fibrosis by Delivering miR-200a.

BACKGROUND: Hepatic fibrosis (HF) is a common pathological feature of chronic hepatic diseases. We aimed to illuminate the significance of amniotic mesenchymal stem cells (AMSCs)-derived extracellular vesicles (AMSCs-EVs) in HF. METHODS: Human AMSCs-EVs were isolated and identified. HF mice were constructed and treated with EVs. The fibrosis was observed by staining experiments and Western blot (WB) assay. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), and hepatic hydroxyproline (Hyp) were detected to confirm liver function. For the in vitro experiments, human hepatic stellate cells were induced with transforming growth factor-ß and treated with EVs. To measure the degree of HF, the expression of alpha-smooth muscle actin (α-SMA) and Collagen I was detected by WB assay, and cell proliferation was detected by cell counting kit 8 assay. The levels of miR-200a, Zinc finger E-box binding homeobox 1 (ZEB1), and phosphoinositide-3-kinase regulatory subunit 3 (PIK3R3) were detected by WB and real-time quantitative polymerase chain reaction. The binding of ZEB1 to PIK3R3 and miR-200a to ZEB1 was analyzed by chromatin immunoprecipitation and dual luciferase assays to validate their relationships. RESULTS: Human AMSCs and AMSCs-EVs were obtained. Serum ALT, AST, TBIL, and hepatic Hyp were increased, implying the fibrosis degree was aggravated in HF mice, which was decreased again after EV treatment. EVs inhibited HF degree by reducing α-SMA and Collagen I and promoting cell proliferation. AMSCs-EVs delivered miR-200a into hepatocytes, which up-regulated miR-200a expression, inhibited ZEB1 expression, and reduced its enrichment on the PIK3R3 promoter, therefore inhibiting PIK3R3 expression and alleviating HF. Overexpression of ZEB1 or PIK3R3 attenuated the anti-fibrotic effect of AMSCs-EVs. CONCLUSION: Human AMSCs-derived EVs mediated miR-200a delivery and inhibition of intracellular ZEB1/PIK3R3 axis to exert anti-fibrosis effects.

Sja-let-7 suppresses the development of liver fibrosis via Schistosoma japonicum extracellular vesicles.

Schistosomiasis is a fatal zoonotic parasitic disease that also threatens human health. The main pathological features of schistosomiasis are granulomatous inflammation and subsequent liver fibrosis, which is a complex, chronic, and progressive disease. Extracellular vesicles (EVs) derived from schistosome eggs are broadly involved in host-parasite communication and act as important contributors to schistosome-induced liver fibrosis. However, it remains unclear whether substances secreted by the EVs of Schistosoma japonicum, a long-term parasitic "partner" in the hepatic portal vein of the host, also participate in liver fibrosis. Here, we report that EVs derived from S. japonicum worms attenuated liver fibrosis by delivering sja-let-7 into hepatic stellate cells (HSCs). Mechanistically, activation of HSCs was reduced by targeting collagen type I alpha 2 chain (Col1α2) and downregulation of the TGF-ß/Smad signaling pathway both in vivo and in vitro. Overall, these results contribute to further understanding of the molecular mechanisms underlying host-parasite interactions and identified the sja-let-7/Col1α2/TGF-ß/Smad axis as a potential target for treatment of schistosomiasis-related liver fibrosis.

The effect of saraglitazar on TGF-ß-induced smad3 phosphorylation and expression of genes related to liver fibrosis in LX2 cell line.

BACKGROUND AND PURPOSE: Liver fibrosis is a reversible liver injury that occurs as a result of many chronic inflammatory diseases and can lead to cirrhosis, which is irreversible and fatal. So, we studied the anti-fibrotic effects of saroglitazar on LX-2 cell lines, as a dual PPARα/γ agonist. METHODS: Cells, after 80% confluence, were treated with TGF-ß (2 ng/mL) for 24 h. Then cells were treated with saroglitazar at different doses (2.5, 5, 10 µM) for 24 h. After same incubation, the cells of control group, TGF-ß group, and TGF-ß + saroglitazar group were harvested for RNA and protein extraction to determine the effects of saroglitazar. RT-PCR and western blot methods were used to express genes related to fibrosis. RESULTS: Our results show that the relative expression of α-SMA, collagen1α, N-cadherin, NOX (1, 2, and 4), and phosphorylated Smad3 protein was significantly higher in TGF-ß-treated cells compared with the normal group, and E-cadherin expression was decreased in TGF-ß-treated cells. After TGF-ß-treated cells were exposed to saroglitazar, the expression of these genes was significantly reversed (P < 0.05). CONCLUSIONS: Our results clearly show the short-term inhibitory role of saroglitazar in the expression of fibrotic factors using the TGF-ß/Smad signaling pathway. These results suggest that saroglitazar can be considered as a suitable therapeutic strategy for fibrotic patients. Although more studies are needed.

LncRNA FRMD6-AS1/miR-491-5p/USP13 pathway attenuated ferroptosis and contributed to liver fibrosis.

Liver fibrosis is an invertible pathophysiologic process featured by excessive accumulation of extracellular matrix (ECM) which injures liver cells and activates hepatic stellate cells (HSCs). Besides, inducing ferroptosis in activated HSCs can alleviate liver fibrosis. LncRNAs modulate ferroptosis in activated HSCs and ECM deposition in liver fibrosis. However, the role of lncRNA FRMD6-AS1 in liver fibrosis is not discovered. In this study, lncRNA FRMD6-AS1 was dramatically up-regulated in activated HSCs. Knockdown of FRMD6-AS1 markedly increased iron ion, ROS and MDA levels, decreased GSH level, SLC7A11 and GPX4 protein expressions in activated HSCs. In addition, HSCs activation markers α-SMA and COL1α1 expressions were up-regulated in activated HSCs; knockdown of FRMD6-AS1 markedly down-regulated α-SMA and COL1α1 expressions in HSCs. Besides, lncRNA FRMD6-AS1 could interact with miR-491-5p, and negatively modulate miR-491-5p expression. USP13 was a target of miR-491-5p, and could be negatively modulated by miR-491-5p. Moreover, FRMD6-AS1 knockdown increased iron ion and ROS levels, decreased SLC7A11 and GPX4 protein expressions, facilitated HSCs viability, and up-regulated α-SMA and COL1α1 expressions via miR-491-5p/USP13 pathway. Finally, FRMD6-AS1 knockdown restored liver tissue structure and abrogated fibrosis in livers in a CCL4 liver fibrosis mouse model. Hence, lncRNA FRMD6-AS1/miR-491-5p/USP13 pathway repressed ferroptosis, promoted ECM deposition and facilitated liver fibrosis in vitro and in vivo models.

Single-cell multiomics guided mechanistic understanding of Fontan-associated liver disease.

The Fontan operation is the current standard of care for single-ventricle congenital heart disease. Individuals with a Fontan circulation (FC) exhibit central venous hypertension and face life-threatening complications of hepatic fibrosis, known as Fontan-associated liver disease (FALD). The fundamental biology and mechanisms of FALD are little understood. Here, we generated a transcriptomic and epigenomic atlas of human FALD at single-cell resolution using multiomic snRNA-ATAC-seq. We found profound cell type-specific transcriptomic and epigenomic changes in FC livers. Central hepatocytes (cHep) exhibited the most substantial changes, featuring profound metabolic reprogramming. These cHep changes preceded substantial activation of hepatic stellate cells and liver fibrosis, suggesting cHep as a potential first "responder" in the pathogenesis of FALD. We also identified a network of ligand-receptor pairs that transmit signals from cHep to hepatic stellate cells, which may promote their activation and liver fibrosis. We further experimentally demonstrated that activins A and B promote fibrotic activation in vitro and identified mechanisms of activin A's transcriptional activation in FALD. Together, our single-cell transcriptomic and epigenomic atlas revealed mechanistic insights into the pathogenesis of FALD and may aid identification of potential therapeutic targets.

Alteration of Gut Microbiota Composition in the Progression of Liver Damage in Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD).

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a complex disorder whose prevalence is rapidly growing in South America. The disturbances in the microbiota-gut-liver axis impact the liver damaging processes toward fibrosis. Gut microbiota status is shaped by dietary and lifestyle factors, depending on geographic location. We aimed to identify microbial signatures in a group of Chilean MASLD patients. Forty subjects were recruited, including healthy controls (HCs), overweight/obese subjects (Ow/Ob), patients with MASLD without fibrosis (MASLD/F-), and MASLD with fibrosis (MASLD/F+). Both MASLD and fibrosis were detected through elastography and/or biopsy, and fecal microbiota were analyzed through deep sequencing. Despite no differences in α- and ß-diversity among all groups, a higher abundance of Bilophila and a lower presence of Defluviitaleaceae, Lachnospiraceae ND3007, and Coprobacter was found in MASLD/F- and MASLD/F+, compared to HC. Ruminococcaceae UCG-013 and Sellimonas were more abundant in MASLD/F+ than in Ow/Ob; both significantly differed between MASLD/F- and MASLD/F+, compared to HC. Significant positive correlations were observed between liver stiffness and Bifidobacterium, Prevotella, Sarcina, and Acidaminococcus abundance. Our results show that MASLD is associated with changes in bacterial taxa that are known to be involved in bile acid metabolism and SCFA production, with some of them being more specifically linked to fibrosis.

DCDC2 inhibits hepatic stellate cell activation and ameliorates CCl4-induced liver fibrosis by suppressing Wnt/ß-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-ß1) 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-ß1. Additionally, we provided evidence that the Wnt/ß-catenin signaling pathway was involved in this process, wherein DCDC2 was observed to inhibit ß-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-ß1-activated HSC. DCDC2 inhibited the activation of HSC induced by TGF-ß1 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.

BMP7-Loaded Human Umbilical Cord Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Ameliorate Liver Fibrosis by Targeting Activated Hepatic Stellate Cells.

Purpose: Human umbilical cord mesenchymal stem cell (hucMSC)-derived small extracellular vesicles (sEVs) are natural nanocarriers with promising potential in treating liver fibrosis and have widespread applications in the fields of nanomedicine and regenerative medicine. However, the therapeutic efficacy of natural hucMSC-sEVs is currently limited owing to their non-specific distribution in vivo and partial removal by mononuclear macrophages following systemic delivery. Thus, the therapeutic efficacy can be improved through the development of engineered hucMSC-sEVs capable to overcome these limitations. Patients and Methods: To improve the anti-liver fibrosis efficacy of hucMSC-sEVs, we genetically engineered hucMSC-sEVs to overexpress the anti-fibrotic gene bone morphogenic protein 7 (BMP7) in parental cells. This was achieved using lentiviral transfection, following which BMP7-loaded hucMSC-sEVs were isolated through ultracentrifugation. First, the liver fibrosis was induced in C57BL/6J mice by intraperitoneal injection of 50% carbon tetrachloride (CCL4) twice a week for 8 weeks. These mice were subsequently treated with BMP7+sEVs via tail vein injection, and the anti-liver fibrosis effect of BMP7+sEVs was validated using small animal in vivo imaging, immunohistochemistry (IHC), tissue immunofluorescence, and enzyme-linked immunosorbent assay (ELISA). Finally, cell function studies were performed to confirm the in vivo results. Results: Liver imaging and liver histopathology confirmed that the engineered hucMSC-sEVs could reach the liver of mice and aggregate around activated hepatic stellate cells (aHSCs) with a significantly stronger anti-liver fibrosis effect of BMP7-loaded hucMSC-sEVs compared to those of blank or negative control-transfected hucMSC-sEVs. In vitro, BMP7-loaded hucMSC-sEVs promoted the phenotypic reversal of aHSCs and inhibited their proliferation to enhance the anti-fibrotic effects. Conclusion: These engineered BMP7-loaded hucMSC-sEVs offer a novel and promising strategy for the clinical treatment of liver fibrosis.

METTL14 downregulation drives S100A4+ monocyte-derived macrophages via MyD88/NF-κB pathway to promote MAFLD progression.

Without intervention, a considerable proportion of patients with metabolism-associated fatty liver disease (MAFLD) will progress from simple steatosis to metabolism-associated steatohepatitis (MASH), liver fibrosis, and even hepatocellular carcinoma. However, the molecular mechanisms that control progressive MAFLD have yet to be fully determined. Here, we unraveled that the expression of the N6-methyladenosine (m6A) methyltransferase METTL14 is remarkably downregulated in the livers of both patients and several murine models of MAFLD, whereas hepatocyte-specific depletion of this methyltransferase aggravated lipid accumulation, liver injury, and fibrosis. Conversely, hepatic Mettl14 overexpression alleviated the above pathophysiological changes in mice fed on a high-fat diet (HFD). Notably, in vivo and in vitro mechanistic studies indicated that METTL14 downregulation decreased the level of GLS2 by affecting the translation efficiency mediated by YTHDF1 in an m6A-depedent manner, which might help to form an oxidative stress microenvironment and accordingly recruit Cx3cr1+Ccr2+ monocyte-derived macrophages (Mo-macs). In detail, Cx3cr1+Ccr2+ Mo-macs can be categorized into M1-like macrophages and S100A4-positive macrophages and then further activate hepatic stellate cells (HSCs) to promote liver fibrosis. Further experiments revealed that CX3CR1 can activate the transcription of S100A4 via CX3CR1/MyD88/NF-κB signaling pathway in Cx3cr1+Ccr2+ Mo-macs. Restoration of METTL14 or GLS2, or interfering with this signal transduction pathway such as inhibiting MyD88 could ameliorate liver injuries and fibrosis. Taken together, these findings indicate potential therapies for the treatment of MAFLD progression.