Liver fibrosis is a reversible pathophysiological condition characterized by excessive extracellular matrix deposition that can progress to cirrhosis and liver failure if left untreated. Taurine, a sulfur-containing amino acid, protects the liver from damage. However, the effects of taurine on liver fibrogenesis have not been completely elucidated. In this study, we used amino acid metabolomics, gene expression microanalysis, and single-cell RNA sequencing (scRNA-seq) to investigate the roles of taurine, formyl peptide receptor 2 (Fpr2), and proinflammatory macrophages in liver fibrosis in human fibrotic sections and two distinct mouse models of liver fibrosis. Taurine transporter SLC6A6 wild-type and knockout littermate models and critical element inhibitors were also used. We found that taurine levels were significantly reduced in both human and murine fibrotic sections and that exogenous taurine supplementation alleviated fibrosis via SLC6A6. Furthermore, gene expression microarray analysis and scRNA-seq analyses demonstrated that exogenous taurine mitigated liver fibrosis, mainly by regulating Fpr2-related macrophage status. WRW4-mediated inhibition of Fpr2 ameliorated M1 macrophage polarization and alleviated liver fibrosis. Additionally, exogenous taurine suppressed Fpr2-modulated macrophage M1 polarization and the production of associated proinflammatory cytokines by repressing NF-κBp65 phosphorylation; moreover, SLC6A6 deficiency or treatment of liver fibrosis mouse models with an NF-κB inhibitor, BAY, impaired this protective effect of taurine. Therefore, taurine exerts a protective effect against liver fibrosis by repressing Fpr2/NF-κBp65-regulated macrophage M1 polarization, highlighting its potential therapeutic agent.

Hepatic fibrosis is a late-stage process of many chronic liver diseases. Blocking the fibrosis process will be beneficial to the treatment and recovery of the disease. Hepatic macrophages are a remarkably heterogeneous population of immune cells that play multiple functions in homeostasis and are central to liver fibrosis. Glycolysis-mediated macrophage metabolic reprogramming leads to an increase in the proportion of M1 macrophages and the release of pro-inflammatory cytokines. The present study aimed to investigate the therapeutic effect and mechanism of Astragaloside IV (AS-IV) against carbon tetrachloride (CCl4)-induced liver fibrosis. The study found that AS-IV is an effective agent for reducing the production of inflammatory factors in CCl4-induced liver fibrosis. It was also found that AS-IV blocks macrophage M1 polarization and relieves liver fibrosis. Mechanistically, AS-IV reduces the methylation level of the FoxO1 promoter region and then upregulates its expression. FoxO1 can inhibit the expression of key enzymes in the glycolysis pathway and block glycolysis-mediated macrophage M1 polarization. Our findings indicate that AS-IV is an attractive option for treating liver fibrosis.

Non-alcoholic steatohepatitis (NASH) has emerged as a prevalent chronic liver disease with a huge unmet clinical need. A few studies have reported the beneficial effects of Poria cocos Wolf (P. cocos) extract on NASH mice, but the active components were still unknown. In this study we investigated the therapeutic effects of dehydrotrametenolic acid methyl ester (ZQS5029-1), a lanosterol-7,9(11)-diene triterpenes in P. cocos, in a high-fat diet plus CCl4 induced murine NASH model and a GAN diet induced ob/ob murine NASH model. The NASH mice were treated with ZQS5029-1 (75 mg·kg-1·d-1, i.g.) for 6 and 8 weeks, respectively. We showed that ZQS5029-1 treatment markedly relieved liver injury, inflammation and fibrosis in both the murine NASH models. We found that ZQS5029-1 treatment significantly suppressed hepatic NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation in both the NASH murine models, and blocked lipopolysaccharides (LPS)+adenosine 5'-triphosphate (ATP)/Nigericin-induced NLRP3 inflammasome activation in bone marrow-derived macrophages (BMDMs) and Kupffer cells in vitro. We demonstrated that ZQS5029-1 directly bound to the H236 residue of mouse Caspase-1, thereby inhibiting NLRP3 inflammasome activation. The effects of ZQS5029-1 on macrophage-hepatocyte/HSC crosstalk were analyzed using the supernatants from macrophages preconditioned with LPS + ATP introduced into hepatocytes and hepatic stellate cells (HSCs). We found that the conditioned medium from the BMDMs induced injury and death, as well as lipid accumulation in hepatocytes, and activation of HSCs; these effects were blocked by conditioned medium from BMDMs treated with ZQS5029-1. Moreover, the protective effects of ZQS5029-1 on hepatocytes and HSCs were eliminated by H236A-mutation of Caspase-1. We conclude that ZQS5029-1 is a promising lead compound for the treatment of NASH by inhibiting NLRP3 inflammasome activation through targeting Caspase-1 and regulating the macrophage-hepatocyte/HSC crosstalk.

Autophagy plays an important role in liver regeneration. However, most studies are limited to hepatocytes, and the function and mechanism of macrophage autophagy in liver regeneration remain unclear. This study investigated the role of the essential autophagy gene encoding autophagy-related 16-like 1 (ATG16L1), which regulates the macrophage phenotype in liver regeneration.

We generated FloxP-Atg16l1 (Atg16l1 FL/FL ), Lyz2-Cre Atg16l1 knockout (KO) (Atg16l1 M-KO ), and myeloid-specific Atg16l1-overexpression-knock-in (Atg16l1 OE ) mice. These mice were subjected to 70% partial hepatectomy to demonstrate the role of ATG16L1 in macrophages during liver regeneration.

ATG16L1 expression was significantly upregulated in macrophages during the early stages of liver regeneration. ATG16L1 deletion in macrophages substantially delayed liver regeneration in mice and caused a marked imbalance in Ly6Chi and Ly6Clo macrophage proportions in the liver. RNA-sequencing analysis revealed that, compared with macrophages isolated from Atg16l1 FL/FL mice, those from Atg16l1 M-KO mice exhibited significant downregulation of genes associated with oxidative phosphorylation and upregulation of proinflammatory gene expression. Mechanistically, ATG16L1 loss impaired mitophagy in macrophages, leading to the accumulation of mitochondrial damage and a metabolic shift that promoted proinflammatory macrophage polarization. ATG16L1 deficiency not only promoted macrophage mitochondrial (mt)DNA release and cyclic GMP-AMP synthase-stimulator of interferon genes (STING) activation, but also suppressed STING degradation. Sustained STING hyperactivation and subsequent increased release of downstream interferons further contributed to the inhibition of liver regeneration. Notably, pharmacological activation or genetic overexpression of ATG16L1 significantly enhanced liver regeneration in mice.

ATG16L1 has a pivotal role in liver regeneration by affecting the phenotype and function of macrophages. Thus, targeting ATG16L1 in macrophages could present a novel strategy for promoting liver regeneration.

The autophagy-related gene ATG16L1 mediates mitophagy, facilitating the clearance of damaged mitochondria in macrophages following partial hepatectomy and maintaining a reparative macrophage phenotype. ATG16L1 deficiency triggers excessive STING activation and inhibits its degradation, thereby suppressing liver regeneration. Thus, targeting ATG16L1 in macrophages could represent a novel strategy to promote liver regeneration.

Hepatopulmonary syndrome (HPS) is a pulmonary vascular complication of liver disease and/or portal hypertension. HPS manifests as impaired gas exchange and hypoxemia due to intrapulmonary vascular dilatations and shunts. In response to primary liver disease, the abnormal adaptation of respiratory epithelial cells, pulmonary endothelial cells and immune cells leads to pulmonary microenvironment disequilibrium and HPS. In this review, we explore the pathophysiologic mechanisms of HPS, including vascular dilation, angiogenesis and alveolar dysfunction. The liver is the primary contributor to HPS, and liver transplantation is the only treatment that generally reverses HPS. We then discuss how disruption of hepatic sinusoidal homeostasis may impact the progression of HPS, mainly focusing on hepatocytes, cholangiocytes, LSECs and macrophages. As HPS occurs more commonly in advanced liver cirrhosis, we also discuss that normalisation of liver dysfunction and portal hypertension is crucial for the resolution of HPS. In conclusion, liver-targeted therapies may be effective in treating HPS.

During Clonorchis sinensis (C. sinensis) infection, pro-inflammatory macrophages (M1 macrophages) are highly activated, yet their role in the disease remains poorly understood. Previous studies have demonstrated that extracellular vesicles from C. sinensis (CsEVs) can activate these macrophages, and inhibiting a specific miRNA (Csi-let-7a-5p) in CsEVs (InCsEVs) can reduce this activation. In the present study, liver macrophages in mice were removed using clodronate liposomes (Clodlip). Subsequently, different types of bone marrow-derived macrophages (BMDMs) were adoptively transferred into the mice lacking liver macrophages: untreated (PBS-BMDM), treated with CsEVs (CsEVs-BMDM), treated with a control (ScrCsEVs-BMDM), or treated with InCsEVs (InCsEVs-BMDM). Biliary damages were then evaluated. The results indicated that the transferred macrophages successfully repopulated the mice. CsEVs-BMDM led to significant inflammation and bile duct damage, accompanied by higher levels of inflammatory cytokines (TNF-α and IL-1β). However, when macrophages were treated with InCsEVs, the damage and inflammation were alleviated, and the levels of TNF-α and IL-1β decreased. These findings suggest that pro-inflammatory macrophages activated by CsEVs, especially through Csi-let-7a-5p, play a crucial role in biliary damage during C. sinensis infection. Although other immune cells may also be involved, this study emphasizes the significance of pro-inflammatory macrophages in clonorchiasis.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a series of obesity-related metabolic liver diseases, ranging from relatively benign hepatic steatosis to metabolic-associated steatohepatitis (MASH). With the changes in lifestyle, its incidence and prevalence have risen to epidemic proportions globally. In recent years, an increasing amount of evidence has indicated that the hepatic microenvironment is involved in the pathophysiological processes of MASH-induced liver fibrosis and the formation of hepatocellular carcinoma (HCC). The hepatic microenvironment is composed of various parenchymal and non-parenchymal cells, which communicate with each other through various factors. In this review, we focus on the changes in hepatocytes, cholangiocytes, liver sinusoidal endothelial cells (LSECs), hepatic stellate cells (HSCs), Kupffer cells (KC), dendritic cells (DC), neutrophils, monocytes, T and B lymphocytes, natural killer cells (NK), natural killer T cells (NKT), mucosal-associated invariant T cells (MAIT), γδT cells, and gut microbiota during the progression of MASLD. Furthermore, we discuss promising therapeutic strategies targeting the microenvironment of MASLD-MASH-HCC.

Inhibition of hepatic stellate cell (HSC) activation and reversal of its activation state represent two distinct yet complementary strategies in antifibrotic therapy. While synergy of those two strategies is anticipated to improve the therapeutic outcomes, synergism through nanomedicine remains elusive. Herein, we report a circular spherical nucleic acid (cSNA) with a supramolecular core comprising collagenase I and ML-290 and a surface attached with circular PDGF-BB aptamer instead of the stereotypical linear counterpart. Unlike conventional inert SNA, this cSNA core dissociates in response to elevated ROS levels in the fibrotic liver so that collagenase I is released to disrupt the collagen barrier to promote the penetration of ensuing nanoparticles. Of significant importance is that the PDGF-BB aptamer after circularization exhibits enhanced nuclease resistance and improved molecular recognition, thereby demonstrating superior capability in blocking HSC activation mediated by PDGF-BB/PDGFR-β signaling. Meanwhile, relaxin family peptide receptor 1 (RXFP1) agonist ML-290 initially transforms pro-fibrogenic macrophages into pro-resolution macrophages by activating RXFP1 signaling, facilitating the secretion of pro-resolution factors for the reversal of the activated state of HSCs. This work thus presents a proof-of-concept demonstration of a supramolecular SNA that undergoes structural and functional refinements, enabling concurrent upstream etiological blockade and downstream pathological restoration in liver fibrosis.

Liver Sinusoidal Endothelial Cells (LSECs) play a crucial role in maintaining liver homeostasis, regulating immune responses, and fibrosis in liver diseases. This review explores the unique functions of LSECs in liver pathology, particularly their roles in immune tolerance, antigen presentation, and the modulation of hepatic stellate cells (HSCs) during fibrosis. LSECs act as key regulators of immune balance in the liver by preventing excessive immune activation while also filtering antigens and interacting with immune cells, including Kupffer cells and T cells. Metabolic Dysfunction-Associated Fatty Liver Disease(MAFLD) is significant because it can lead to advanced liver dysfunction, such as cirrhosis and liver cancer. The prevalence of Metabolic Associated Steatohepatitis (MASH) is increasing globally, particularly in the United States, and is closely linked to rising rates of obesity and type 2 diabetes. Early diagnosis and intervention are vital to prevent severe outcomes, highlighting the importance of studying LSECs in liver disease. However, during chronic liver diseases, LSECs undergo dysfunction, leading to their capillarization, loss of fenestrations, and promotion of pro-fibrotic signaling pathways such as Transforming growth factor-beta (TGF-β), which subsequently activates HSCs and contributes to the progression of liver fibrosis. The review also discusses the dynamic interaction between LSECs, HSCs, and other hepatic cells during the progression of liver diseases, emphasizing how changes in LSEC phenotype contribute to liver scarring and fibrosis. Furthermore, it highlights the potential of LSECs as therapeutic targets for modulating immune responses and preventing fibrosis in liver diseases. By restoring LSECs' function and targeting pathways associated with their dysfunction, novel therapies could be developed to halt or reverse liver disease progression. The findings of this review reinforce the importance of LSECs in liver pathology and suggest that they hold significant promises as targets for future treatment strategies aimed at addressing chronic liver diseases.

Macrophage pyroptosis represents a pivotal mechanism underlying acute liver injury during sepsis. Chloride intracellular channel proteins (CLICs) have been linked to inflammatory reflexes, with IAA94 serving as an inhibitor of channel formation characteristic of CLICs. In a mouse model, IAA94 demonstrated efficacy in reducing pro-inflammatory cytokines in liver tissues, decreasing macrophage in the liver, inhibiting the development of the pro-fibrosis phenotype, and alleviating tissue injury. Additionally, IAA94 exhibited inhibitory effects on the activation of NLRP3 inflammasome, leading to the suppression of pyroptosis in J774A.1 cells and the liver. Additionally, IAA94 was observed to impede the interaction between NEK7 and NLRP3. Furthermore, it was observed that the conditioned medium of pyroptotic macrophages treated with IAA94 induced an attenuated inflammatory response in hepatocytes in comparison to that induced by the conditioned medium of pyroptotic macrophages. However, NLRP3 overexpression impeded the beneficial effects of IAA94. In conclusion, IAA94 has the capacity to impede NLRP3 inflammasome formation-mediated pyroptosis by blocking CLICs-mediated chloride efflux and the inhibition of NEK7-NLRP3 interactions, thereby establishing CLICs as a promising therapeutic target against liver inflammation.

Curcumin (CUR), a bioactive compound found in turmeric, has garnered attention for its potential anti-inflammatory properties and impact on liver health. Numerous studies suggest that CUR may be crucial in mitigating liver inflammation. The compound's anti-inflammatory effects are believed to be attributed to its ability to modulate various molecular pathways involved in the inflammatory response. Research indicates that CUR may suppress the activation of inflammatory cells and the production of pro-inflammatory cytokines in the liver. Additionally, it has been observed to inhibit the activity of transcription factors that play a key role in inflammation. By targeting these molecular mechanisms, CUR may help alleviate the inflammatory burden on the liver. Moreover, CUR's antioxidant properties are thought to contribute to its protective effects on the liver. Oxidative stress is closely linked to inflammation, and CUR's ability to neutralize free radicals may further support its anti-inflammatory action. While the evidence is promising, it is essential to note that more research is needed to fully understand the precise mechanisms through which CUR influences liver inflammation. Nevertheless, these findings suggest that CUR could be a potential therapeutic agent in managing liver inflammatory conditions. In this review, we explore the potential impact of CUR on inflammation, highlighting the key mechanisms involved, as reported in the literature.

Immune cells are central mediators of the immune response and play critical roles in the pathogenesis and progression of liver diseases. Understanding the specific contributions of immune cells to liver disease progression is essential for developing targeted therapeutic strategies. In this study, we employed a two-sample Mendelian randomization (MR) approach to explore potential causal relationships between peripheral immune cell phenotypes and liver diseases, using genetic instrumental variables from large-scale genome-wide association studies (GWAS). Applying the inverse variance weighted (IVW) methods, we identified that monocyte count(odds ratio (OR) 0.81; 95% confidence interval (CI) 0.74-0.90; P  =  5.95 × 10- 5, PFDR = 3.57 × 10- 4), CD3- lymphocyte/lymphocyte (OR 0.59, 95% CI 0.45-0.79; P  =  3.29 × 10- 4, PFDR = 5.92 × 10- 3) and SSC-A (Side Scatter Area) on Natural Killer (NK) cells (OR 0.89, 95% CI 0.82-0.95; P  =  1.37 × 10- 3, PFDR = 0.0396) acted as protective factors against alcoholic liver disease. Similarly, the trait HLA DR++ monocyte/monocyte was associated with a lower risk of autoimmune hepatitis (OR 0.56, 95% CI 0.41-0.79; P  =  7.42 × 10- 4, PFDR = 0.0475). Conversely, an elevated blood monocytic Myeloid-Derived Suppressor Cells (MDSCs) count was associated with a higher risk of chronic hepatitis (OR 1.23, 95% CI 1.11-1.37; P  =  1.13 × 10- 4, PFDR = 1.58 × 10- 3). Similarly, higher levels of HLA DR on CD14- CD16+ monocyte (OR 0.84, 95% CI 0.78-0.91; P  =  2.07 × 10- 5, PFDR = 1.32 × 10- 3) conferred lower risk for cirrhosis of liver. In hepatic failure, CD39+ resting CD4 regulatory T cell count (OR 0.85, 95% CI 0.79-0.92; P  =  1.70 × 10- 5, PFDR = 5.25 × 10- 3) played a protective role and CD28+ CD45RA- CD8dim T cell/CD8dim T cell (OR 1.14, 95% CI 1.06-1.22; P  =  2.63 × 10- 4, PFDR = 0.0406) exhibited a risk function. Our findings highlight key immune pathways in liver disease progression and underscore potential immunomodulatory targets for future therapeutic interventions. Further research is warranted to clarify the mechanistic underpinnings of these associations.

Coronary atherosclerotic heart disease (CHD) is one of the leading causes of death from cardiovascular disease worldwide and has significant inflammatory features. Macrophages play an important role in atherosclerotic plaque formation and inflammation. IL-17, as a pro-inflammatory cytokine, further exacerbates the development of CHD by interacting with macrophages. In recent years, there has been increasing evidence that traditional Chinese medicine (CM) has a wide range of applications in regulating the immune system and treating CHD. This article reviewed the role of CM in the regulation of IL-17-regulated macrophages, discussed the core components and targets of CM in the treatment of CHD, and laid a theoretical foundation for its clinical application. The results show that CM can effectively inhibit the formation of foam cells, stabilize vulnerable plaque and delay the progression of atherosclerosis by inhibiting inflammation, regulating the polarization of macrophages and promoting cholesterol outflow. In addition, CM can also regulate the expression and signaling pathway of IL-17, further inhibit inflammatory response and improve the symptoms of CHD, providing a new idea and method for the prevention and treatment of CHD.

Recent research has highlighted the complex relationship between gut microbiota, metabolic pathways, and nonalcoholic fatty liver disease (NAFLD) progression. Gut dysbiosis, commonly observed in NAFLD patients, impairs intestinal permeability, leading to the translocation of bacterial products like lipopolysaccharides, short-chain fatty acids, and ethanol to the liver. These microbiome-associated mechanisms contribute to intestinal and hepatic inflammation, potentially advancing NAFLD to NASH. Dietary habits, particularly those rich in saturated fats and fructose, can modify the microbiome composition, leading to dysbiosis and fatty liver development. Metabolomic approaches have identified unique profiles in NASH patients, with specific metabolites like ethanol linked to disease progression. While bariatric surgery has shown promise in preventing NAFLD progression, the role of gut microbiome and metabolites in this improvement remains to be proven. Understanding these microbiome-related pathways may provide new diagnostic and therapeutic targets for NAFLD and NASH. A comprehensive review of current literature was conducted using multiple medical research databases, including PubMed, Scopus, Web of Science, Embase, Cochrane Library, ClinicalTrials.gov, ScienceDirect, Medline, ProQuest, and Google Scholar. The review focused on studies that examine the relationship between gut microbiota composition, metabolic pathways, and NAFLD progression. Key areas of interest included microbial dysbiosis, endotoxin production, and the influence of diet on gut microbiota. The analysis revealed that gut dysbiosis contributes to NAFLD through several mechanisms, diet significantly influences gut microbiota composition, which in turn affects liver function through the gut-liver axis. High-fat diets can lead to dysbiosis, altering microbial metabolic activities and promoting liver inflammation. Specifically, gut microbiota-mediated generation of saturated fatty acids, such as palmitic acid, can activate liver macrophages and increase TNF-α expression, contributing to NASH development. Different dietary components, including cholesterol, fiber, fat, and carbohydrates, can modulate the gut microbiome and influence NAFLD progression. This gut-liver axis plays a crucial role in maintaining immune homeostasis, with the liver responding to gut-derived bacteria by activating innate and adaptive immune responses. Microbial metabolites, such as bile acids, tryptophan catabolites, and branched-chain amino acids, regulate adipose tissue and intestinal homeostasis, contributing to NASH pathogenesis. Additionally, the microbiome of NASH patients shows an elevated capacity for alcohol production, suggesting similarities between alcoholic steatohepatitis and NASH. These findings indicate that targeting the gut microbiota may be a promising approach for NASH treatment and prevention. Recent research highlights the potential of targeting gut microbiota for managing nonalcoholic fatty liver disease (NAFLD). The gut-liver axis plays a crucial role in NAFLD pathophysiology, with dysbiosis contributing to disease progression. Various therapeutic approaches aimed at modulating gut microbiota have shown promise, including probiotics, prebiotics, synbiotics, fecal microbiota transplantation, and dietary interventions. Probiotics have demonstrated efficacy in human randomized controlled trials, while other interventions require further investigation in clinical settings. These microbiota-targeted therapies may improve NAFLD outcomes through multiple mechanisms, such as reducing inflammation and enhancing metabolic function. Although lifestyle modifications remain the primary recommendation for NAFLD management, microbiota-focused interventions offer a promising alternative for patients struggling to achieve weight loss targets.

Liver macrophages play a role in the development of liver fibrosis progression via the regulation of inflammatory signaling. However, the precise mechanisms of macrophages contributing to liver fibrosis progression remain unclear. Using a preclinical model of CCl4-treated mice, we determined the composition of immune cells and the alteration of inflammatory gene expression. Our findings revealed a significant increase in liver macrophages, particularly those derived from infiltrating blood monocytes, in fibrotic mice. Moreover, the expression levels of type I IFN signature genes such as IFNα, IFNβ, ISG15, USP18, Ifi44, Ifit1, Ifit2, IRF3, and IRF7 were elevated in fibrotic mice. To determine the role of type I IFN signaling in liver fibrosis, we administered an IFNAR-1 antibody to block this pathway for 3 days prior to harvesting the liver. Notably, IFNAR-1 blockade reduced macrophage numbers compared to control mice and alleviated liver fibrosis in mice with increased hepatocyte proliferation and apoptosis. The ratio of P-STAT3/P-STAT1 in monocyte-derived macrophages was increased in the IFNAR-1 blockade group compared to fibrotic mice, and this was related to the appearance of M2 macrophage differentiation. Additionally, single-cell RNA-seq analysis indicated that IFNAR blockade affected inflammatory pathways involved in hepatocyte regeneration and fibrosis prevention. Taken together, IFNAR-1 blockade alleviates liver fibrosis progression by modulating macrophage inflammatory responses. These results provide insights for developing anti-fibrotic therapies against type I IFN signaling.

Osteopontin (OPN) promotes the ductular reaction and is a major driver of chronic liver disease (CLD) progression. Although CLD is characterised by the accumulation of inflammatory cells including macrophages around the peri-portal regions, the influence of OPN on recruitment is unclear. We investigated the role of OPN in cholangiocyte chemokine production and macrophage recruitment by combining in vivo, in vitro, and in silico approaches.

The effects of OPN on cholangiocyte chemokine production and macrophage migration were assessed in culture, alongside RNA-sequencing to identify genes and pathways affected by OPN depletion. Murine liver injury models were used to assess liver chemokine expression and liver macrophage/monocyte recruitment. OPN and chemokine expression were analysed in liver tissue and plasma from biopsy-proven metabolic dysfunction-associated alcoholic steatohepatitis (MASH) patients.

OPN-knockdown in cholangiocytes reduced chemokine secretion. RNA-sequencing showed OPN-related effects clustered around immunity, chemotaxis and chemokine production. Macrophage exposure to cholangiocyte-conditioned media showed OPN-supported migration via chemokines chemokine (C-C motif) ligand (CCL)2, CCL5 and chemokine (C-X-C motif) ligand (CXCL)1. These effects were related to NF-κB signalling. Murine liver fibrosis was accompanied by upregulated liver OPN, CCL2, CCL5 and CXCL1 mRNA, and accumulation of liver cluster of differentiation (CD)11b/F4/80+CC chemokine receptors (CCR2)high macrophages but treatment with OPN-specific neutralising aptamers reduced fibrosis, chemokine mRNAs and accumulation of liver CD11b/F4/80+CCR2high/lymphocyte antigen 6 complexhigh inflammatory monocytes. In human MASH, liver OPN correlated with chemokines CCL2 and IL8 in association with portal injury and fibrosis. Plasma OPN, serum CCL2 and IL8 also increased with fibrosis stage.

OPN promotes cholangiocyte chemokine secretion and the accumulation of pro-inflammatory monocytes. These data support neutralisation of OPN as an anti-inflammatory and anti-fibrotic strategy.

The immunomodulatory characteristics of mesenchymal stem cells (MSCs) make them a promising therapeutic approach for liver fibrosis (LF). Here, we postulated that MSCs could potentially suppress the pro-fibrotic activity of intrahepatic B cells, thereby inhibiting LF progression.

Administration of MSCs significantly ameliorated LF as indicated by reduced myofibroblast activation, collagen deposition, and inflammation. The treatment efficacy of MSCs can be attributed to decreased infiltration, activation, and pro-inflammatory cytokine production of intrahepatic B cells. Single-cell RNA sequencing revealed a distinct intrahepatic B cell atlas, and a subtype of naive B cells (B-II) was identified, which were markedly abundant in fibrotic liver, displaying mature features with elevated expression of several proliferative and inflammatory genes. Transcriptional profiling of total B cells revealed that intrahepatic B cells displayed activation, proliferation, and pro-inflammatory gene profile during LF. Fibrosis was attenuated in mice ablated with B cells (μMT) or in vivo treatment with anti-CD20. Moreover, fibrosis was recapitulated in μMT after adoptive transfer of B cells, which in turn could be rescued by MSC injection, validating the pathogenic function of B cells and the efficacy of MSCs on B cell-promoted LF progression. Mechanistically, MSCs could inhibit the proliferation and cytokine production of intrahepatic B cells through exosomes, regulating the Mitogen-activated protein kinase and Nuclear factor kappa B signaling pathways.

Intrahepatic B cells serve as a target of MSCs, play an important role in the process of MSC-induced amelioration of LF, and may provide new clues for revealing the novel mechanisms of MSC action.

Liver fibrosis (LF) is a common pathological process in the progression of multiple chronic liver diseases to cirrhosis, affecting millions of people worldwide annually. The incomplete understanding of its mechanisms has led to a lack of clinically effective therapeutic options. ErTao decoction (ETD, ), a derivative combining the components of Erchen Decoction and Taohong Siwu Decoction, is rooted in the traditional Chinese medicine theory of "phlegm-dampness-blood stasis". However, the precise mechanism by which ETD exerts its therapeutic effects in LF remains unclear.

The purpose of study was to investigate the protective effect of ETD and elucidate its underlying molecular mechanism on LF.

In this study, we employed a multifaceted approach to evaluate the effects of ETD on LF. We used H&E staining, Sirius red staining, immunofluorescence, immunohistochemical analysis, and Western blotting to assess the protective effects of ETD in a CCl4-induced fibrosis mouse model. In vitro validation was conducted using macrophages and hepatic stellate cells to further elucidate the mechanisms involved. STING-deficient mice were used to assess its regulatory effects on liver injury, inflammatory and activation through immunohistochemical staining and Western blotting. Furthermore, UHPLCHRMS detection and computer-aided drug analysis were employed to identify and validate potential effective components of ETD for responsible for its therapeutic effects in treating LF.

In our in vivo and in vitro experiments, we found that ETD effectively reduced collagen fiber deposition and alleviated LF pathological changes by inhibiting macrophage inflammatory activation and suppressing NLRP3 and STING signaling. Notably, STING deficiency exhibited a protective effect against liver tissue injury and inhibited inflammatory activation of hepatic macrophages in LF model mice. Additionally, comprehensive analysis of the active ingredients in ETD strongly suggested that Naringin served as a pivotal bioactive constituent within ETD responsible for modulating STING signaling.

Our study highlighted the protective effects of ETD on LF by inhibiting STING-mediated macrophage activation and NLRP3 inflammasome signaling. Notably, Naringin might serve as a promising novel STING inhibitor to effectively counteract the progression of LF. These findings represented significant advances in LF research and paved the way for the development of novel therapeutic strategies.

Chronic liver inflammation is a major cause of death in patients with liver fibrosis and cirrhosis, which pose a serious health threat worldwide, and there is no effective anti-hepatic fibrosis drug. Kaempferol (KA), a flavonoid polyphenol extracted from many edible plants and traditional Chinese medicine, has been reported to possess anti-inflammatory, antioxidant, and antitumor activities and has an ameliorating effect on liver fibrosis or other fibroproliferative diseases. However, the specific regulatory mechanism of KA-reversed macrophage M1 polarization is still obscure. This study aimed to investigate the protective effects of KA on carbon tetrachloride (CCl4)-induced liver fibrosis in mice through M1 polarization. C57BL/6 mice were intraperitoneally injected with CCl4 twice weekly to induce liver fibrosis. Male mice were randomly divided into 4 groups (n = 5): the oil group, the CCl4 group, the low-dose KA-treatment CCl4 group (50 mg/kg/day KA), and the high-dose KA-treatment CCl4 group (100 mg/kg/day KA). An equal amount of solvent was given to each group by intraperitoneal injection. The results indicated that KA decreased liver pathologic changes, hepatic macrophage recruitment, and serum alanine aminotransferase levels. Notably, it reduced the activation of M1-type macrophages in the liver. The expression of proinflammatory cytokines and genes associated with M1 macrophages, such as tumor necrosis factor-α, interleukin-6, interleukin-1β, and inducible nitric oxide synthase, was also decreased. The core targets, signaling pathways, and possible mechanisms related to the M1 polarization of KA were analyzed by network pharmacology and molecular docking. Further analysis revealed that KA regulated mitogen-activated protein kinase (MAPK)/nuclear factor κB (NF-κB) signaling pathways. Finally, the results indicated that KA regulates M1 macrophage activation by modulating the MAPK/NF-κB signaling pathways. This study revealed that KA ameliorated liver injury, inflammation, and fibrosis by inhibiting macrophage M1 polarization through the MAPK/NF-κB signaling pathway, highlighting KA as a potential novel agent for the prevention and treatment of liver fibrosis. SIGNIFICANCE STATEMENT: Chronic liver inflammation is a leading cause of mortality in patients with liver fibrosis and cirrhosis, presenting a significant global health threat. Kaempferol, as a traditional Chinese medicine, effectively suppresses M1 polarization of macrophages through the mitogen-activated protein kinase/nuclear factor κB signaling pathway, thereby ameliorating liver injury, inflammation, and fibrosis. These findings underscore the potential of kaempferol as an innovative therapeutic agent for the prevention and treatment of liver fibrosis.

The mechanism underlying chronic drug-induced liver injury (DILI) remains unclear. Immune activation is a common feature of DILI progression and is closely associated with metabolism. We explored the immunometabolic profile of chronic DILI and the potential mechanism of chronic DILI progression.

Plasma and peripheral blood mononuclear cells from patients with chronic DILI were analyzed using multiplex immunoassays and untargeted metabolomics to reveal their immunometabolic profile. The effects and potential mechanisms of chronic DILI-related metabolite on acute or chronic liver injury induced by LPS or CCl4 in mice were investigated.

Patients with chronic DILI exhibited elevated plasma IL-6, IL-12p70, IL-15 and reduced IL-10 levels. The percentage of IL-12+ monocytes was higher, while that of CD206+ monocytes, IL-10+ monocytes, Th2, Treg, and IL-10+ CD4+ T cells were lower in patients with chronic DILI compared to those with acute DILI. We identified the most significantly increased metabolite in patients with chronic DILI was cis-aconitic acid (CAA). Administration of CAA can attenuate liver injury in mice with acute liver injury induced by LPS or CCl4 and promote the spontaneous resolution of liver fibrosis in mice with chronic live injury induced by CCl4. The protective mechanism of CAA against liver injury is associated with the inhibition of hepatic macrophage infiltration and polarization, which is achieved by inhibiting the secretion of neutrophil-derived IL-33 and subsequent phosphorylation of GATA3.

CAA, which is elevated in patients with chronic DILI, protects against liver injury by inhibiting hepatic macrophage infiltration and polarization through the suppression of the IL-33/GATA3 pathway, suggesting that CAA may serve as a potential target for regulating tissue repair in liver injury.

Since its discovery, the patatin-like phospholipase domain containing 3 (PNPLA3) (rs738409 C>G p.I148M) variant has been studied extensively to unravel its molecular function. Although several studies proved a causal relationship between the PNPLA3 I148M variant and MASLD development and particularly fibrosis, the pathological mechanisms promoting this phenotype have not yet been fully clarified.

We summarise the latest data regarding the PNPLA3 I148M variant in hepatic stellate cells (HSCs) activation and macrophage biology or the path to inflammation-induced fibrosis.

Elegant but contradictory studies have ascribed PNPLA3 a hydrolase or an acyltransferase function. The PNPLA3 I148M results in hepatic lipid accumulation, which predisposes the hepatocyte to lipotoxicity and lipo-apoptosis, producing DAMPs, cytokines and chemokines leading to recruitment and activation of macrophages and HSCs, propagating fibrosis. Recent studies showed that the PNPLA3 I148M variant alters HSCs biology via attenuation of PPARγ, AP-1, LXRα and TGFβ activity and signalling.

The advent of refined techniques in isolating HSCs has made PNPLA3's direct role in HSCs for liver fibrosis development more apparent. However, many other mechanisms still need detailed investigations.

This study investigates the relationship between Cyclin D1 (CCND1) gene and promoter methylation and liver fibrosis (LF)/liver cirrhosis (LC)induced by chronic hepatitis B (CHB). Peripheral blood mononuclear cells (PBMCs) are collected from patients diagnosed with chronic hepatitis B (CHB) and hepatitis B-related LF/LC, as well as from healthy individuals. The mRNA levels and promoter methylation of the CCND1 gene are measured. Single-cell analysis is performed to determine the cell types primarily expressing the CCND1 gene in LF/LC. The GSE84044 dataset is utilized to validate the experimental results. Single-gene GSEA and immune infiltration analyses are conducted to identify significant pathways and immune characteristics associated with the CCND1 gene. The mRNA level of CCND1 in PBMCs from patients with hepatitis B-related LF/LC is elevated compared to those with chronic hepatitis B (CHB) and healthy individuals, while the promoter methylation level of CCND1 is reduced. Single-cell analysis indicates high expression of CCND1 in M2 macrophages (M2) and T cells. The GSE84044 dataset confirms higher CCND1 mRNA levels in liver tissues from patients with CHB-related LF/LC compared to CHB patients. Single-gene GSEA analysis associates CCND1 expression with natural killer cell-mediated cytotoxicity, T cell receptor signaling, and B cell receptor signaling pathways. Increased expression of CCND1 enhances immune infiltration during the fibrosis/cirrhosis process of CHB. The CCND1 expression and promoter methylation may be involved in the process of LF/LC in CHB and may be related to the immune response in the course of the disease.

Developing drugs for the treatment of Metabolic Associated Steatohepatitis (MASH) has always been a significant challenge. Researchers have been dedicated to exploring drugs and therapeutic strategies to alleviate disease progression, but treatments remain limited. This is partly due to the complexity of the pathophysiological processes, and inadequate knowledge of the cellular and molecular mechanisms in MASH. Especially, the liver non-parenchymal cells (NPCs) like Kupffer cells, hepatic stellate cells and sinusoidal endothelial cells which play critical roles in live function, immune responses, fibrosis and disease progression. Deciphering how these cells function in MASH, would help understand the pathophysiological processes and find potential drug targets. In recent years, new technologies have been developed for single-cell transcriptomic sequencing, making cell-specific transcriptome profiling a reality in healthy and diseased livers. In this review, we discussed how the use of single-cell transcriptomic sequencing provided us with an in-depth understanding of the heterogeneous, cellular interactions among non-parenchymal cells and tried to highlight recent discoveries in MASH by this technology. It is hoped that the summarized features and markers of various subclusters in this review could provide a technical reference for further experiments and a theoretical basis for clinical applications.

Chitinase-3-like protein 1 (Chi3l1) is a member of the mammalian Chitinase-like protein family, and several studies reported that Chi3l1 is associated with various inflammatory diseases as well as liver diseases. Acetaminophen (APAP) is usually used for antipyretic drug, but its overdose induces acute liver injury (ALI). Several studies reported that subsequent inflammatory responses of the immune system play a critical role in the severity and outcome of APAP-induced ALI. In the present study, we investigated the role of Chi3l1 and its mechanism during APAP-induced ALI using Chi3l1 knock-out (KO) mice. We explored the function of Chi3l1 using APAP-injected KO mice and sought proteins associated with Chi3l1 through biological research data program for investigating mechanism. Liver histological analysis revealed that APAP-induced ALI was attenuated in KO mice compared to wild-type (WT) mice. We observed that APAP-induced neutrophil infiltration was decreased in the liver of KO mice compared to WT mice. To investigate this mechanism, we sought proteins potentially associated with Chi3l1 by mRNA sequencing and protein correlation analysis data. We found lipocalin-2 (Lcn2) and examined Chi3l1, Lcn2, and their relationship in the APAP-induced ALI model using recombinant proteins and antibodies. Our results suggest that Chi3l1 deficiency ameliorates APAP-induced liver injury through abrogating Lcn2-mediated neutrophil infiltration in the liver.

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

Liver fibrosis, a complex process resulting from most chronic liver diseases, remains devoid of effective treatments. An increasing body of evidence links liver fibrosis to the "gut-liver axis", with disruptions in the gut microbiota-host balance emerging as a critical contributor to its progression. Cinnamaldehyde (Cin), a natural compound with antioxidant, anti-inflammatory, and anticytotoxic properties, has shown potential in counteracting hepatic stellate cell (HSC) activation. Additionally, Cin has been shown to promote probiotics in the intestine, thereby restoring a healthy microbial community. These characteristics position Cin as a promising candidate for liver fibrosis treatment through modulation of the gut-liver axis. In this study, a Vitamin A (Va)-formulated Cin Nanoemulsion (Va-Cin@NM) was developed to enhance the physicochemical stability of Cin while preserving intestinal homeostasis and facilitating targeted liver deposition. In bile duct ligation (BDL)-induced liver fibrosis in rats, Va-Cin@NM intervention significantly reduced bile duct-like structure proliferation and collagen deposition in the liver. These effects are likely attributed to the restoration of gut microbiota, increased short-chain fatty acid (SCFA) concentrations, and improved intestinal integrity. Moreover, Va-Cin@NM treatment suppressed harmful bacterial populations in the liver, thus mitigating immune injury and inflammatory cell recruitment. Consequently, oxidative stress and HSC activation were attenuated. Overall, Va-Cin@NM demonstrates significant potential as a nanotherapeutic approach for liver fibrosis by modulating the gut-liver axis.

The burden of chronic liver disease (CLD) is dramatically increasing. It is estimated that 20-30% of the population worldwide is affected by CLD. Hepatic fibrosis is a symptom common to all CLDs. Although it affects liver functional activities, it is a reversible stage if diagnosed at an early stage, but no resolutive therapy to contrast liver fibrosis is currently available. Therefore, efforts are needed to study the molecular insights of the disease. Emerging cutting-edge fields in cellular and molecular biology are introducing innovative strategies. Spatial and single-cell resolution approaches are paving the way for a more detailed understanding of the mechanisms underlying liver fibrosis. Cellular models have been generated to recapitulate the in-a-dish pathophysiology of liver fibrosis, yielding remarkable results that not only uncover the underlying molecular mechanisms but also serve as patient-specific avatars for precision medicine. Induced pluripotent stem cells (iPSC) and organoids are incredible tools to reshape the modeling of liver diseases, describe their architecture, and study the residents of hepatic tissue and their heterogeneous population. The present work aims to give an overview of innovative omics technologies revolutionizing liver fibrosis research and the current tools to model this disease.

Liver fibrosis is characterized by excessive deposition of extracellular matrix due to chronic inflammation of the liver. Hepatic stellate cells (HSCs) become activated and produce increased amounts of extracellular matrix. Loss of HIF-prolyl-hydroxylase 1 (PHD1) attenuates HSC activation and fibrotic tissue remodeling in a murine model of biliary liver fibrosis. Herein, the protective effect of PHD1 deficiency (PHD1-/-) in an additional (toxic) model of liver fibrosis was validated and the effect of dimethyloxalylglycine (DMOG), a pan-HIF-prolyl-hydroxylase inhibitor, on the development of liver fibrosis, was evaluated. Liver fibrosis was induced utilizing carbon tetrachloride in wild-type (WT) and PHD1-/- mice treated with either vehicle or DMOG. To assess fibrosis development, expression of profibrotic genes in the livers was analyzed by Sirius red staining. When compared with WT mice, PHD1-/- mice developed less-severe liver fibrosis. DMOG treatment did not prevent this liver fibrosis. PHD1-/- mice had fewer α-SMA+ cells and less macrophage infiltration compared with WT mice. Expression of profibrogenic and proinflammatory genes was reduced in livers from carbon tetrachloride-exposed PHD1-/- mice. In vitro analyses of PHD1-deficient human HSCs revealed attenuated mRNA levels of profibrotic genes, as well as impaired migration and invasion. Although PHD1 deficiency attenuated activation of HSCs, pharmacologic PHD inhibition did not ameliorate fibrosis development. These data indicate that selective PHD1 inhibitors could prove effective in preventing and treating liver fibrosis.

Subclinical ketosis (SCK) is highly prevalent and easily overlooked, with insidious and slow progression of hepatic injury, often characterized by an imbalance in immune homeostasis. In nonruminants, macrophage polarization plays an important regulatory role in hepatic lipid accumulation, fibrosis, and inflammatory processes. Thus, we aimed to investigate the status of hepatic macrophage polarization in SCK cows and to corroborate its association with liver injury and inflammation. Twelve Holstein dairy cows (parity 2-4) were selected, and liver biopsy and blood were collected on the second week postpartum (10-14 d DIM). On the basis of serum beta-hydroxybutyric acid (BHBA) concentrations, selected cows were categorized into healthy (n = 6; BHBA <1.0 mM) and SCK (n = 6; 1.2 mM ≤ BHBA < 3.0 mM) groups. Serum biochemical parameters were measured using an automatic biochemical analyzer, which indicated higher serum levels of BHBA and nonesterified fatty acids and an upregulation of liver injury indicators (aspartate aminotransferase [AST], alanine aminotransferase [ALT], total protein, globulin) in SCK cows compared with healthy cows. The ELISA assays revealed that SCK cows displayed systemic low-grade inflammation, as demonstrated by increased serum levels of haptoglobin, serum amyloid A, TGF-β, IFN-γ, and IL-1β. Liver biopsies revealed pathological histological alterations, hepatic inflammation, and macrophage polarization status. Oil Red staining indicated steatosis, whereas Sirius red staining demonstrated mild extracellular matrix deposition in the liver of SCK cows. The expression of inflammatory response-related proteins (TLR4, p-NFκB, p-I-κB, NLRP3, and Caspase 1) was elevated in the liver of SCK cows, with the increased mean fluorescence intensity of NFκB further confirming the activation of the inflammatory pathway. Furthermore, the levels of pro-inflammatory factors, TNF-α and IFN-γ, were elevated in the tissue homogenate. Macrophage phenotypic changes in SCK cows were further explored based on the results of liver injury and inflammation. Compared with healthy cows, the protein and mRNA abundance of the macrophage marker CD68 in the liver of SCK cows was higher, along with an increased mean fluorescence intensity of CD68. The SCK cows also exhibited reduced mRNA expression of the Kupffer cell marker CLEC4F and elevated chemokine levels (CXCL1 and CCL2). As evidenced by greater protein and mRNA abundance of macrophage M1 polarization markers (iNOS, IL-1β, CD86, IL-6, IL-12b, and CCL3), higher fluorescence intensity of iNOS and CD86, and an increased number of CD68+/CD86+-positive cells observed via immunofluorescence, the macrophage polarization phenotype in the liver of SCK cows was predominantly M1. In contrast, the protein and mRNA abundances of M2 polarization markers (CD206, IL-10, and Arg1) were lower in SCK cows, accompanied by a reduced fluorescence intensity of CD206 and a lower number of CD68+/CD206+-positive cells. Overall, the present study revealed that the number of macrophages in liver is enhanced during subclinical ketosis and is dominated by pro-inflammatory macrophages (M1 macrophages). This could partly explain the increased risk of steatosis, fibrosis, and inflammatory response processes in these cows.

Echinococcosis, a zoonotic disease, significantly impacts the liver, with alveolar echinococcosis (AE) often leading to liver fibrosis and, in severe cases, cirrhosis. However, the molecular mechanisms by which AE infection promotes liver fibrosis remain incompletely understood. This study utilized bioinformatic analysis of existing microarray data to explore the shared mechanisms between AE and liver fibrosis and to identify potential therapeutic drug candidates. We analyzed gene expression datasets to identify common differentially expressed genes (DEGs), followed by enrichment analyses using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes databases to determine biological functions and pathways. A protein-protein interaction network was constructed, and key hub genes were identified using Cytoscape software. Immune cell infiltration was evaluated and correlated with hub gene expression. Transcription factors regulating DEGs were predicted using the TRRUST database, and drug-target interactions were explored using DrugBank. A total of 260 DEGs were identified, primarily associated with cell cycle regulation and immune response pathways. Ten hub genes (DLGAP5, AURKA, MELK, CCNB2, CCNA2, NUF2, BUB1B, BUB1, TOP2A, and CCNB1) were highlighted for their significant interconnectivity and functional relevance. Immune infiltration analysis revealed dysregulation in immune responses, and transcription factor analysis identified E2F3 as a key regulatory factor with decreased expression in both AE and liver fibrosis. Finally, 135 candidate drugs targeting these hub genes were identified, offering new insights into therapeutic strategies. This study provides a foundation for understanding the molecular mechanisms underlying AE-related liver fibrosis and highlights potential drug candidates for clinical exploration.

The activation of inflammatory macrophages plays a pivotal role in the development of liver fibrosis (LF). Ferroptosis contributes to the clearance of inflammatory macrophages and the release of profibrotic factors. Glycyrrhetic Acid 3-O-Mono-β-d-glucuronide (GAMG) is a natural compound, the potential role of which on LF remains uncertain. In this study, GAMG treatment significantly reduced hepatocyte steatosis, fibroplasia, inflammatory cell infiltration, and collagen fiber deposition in LF mice. In addition, GAMG remarkably decreased the content of collagen protein and improved liver function indicators. Single-cell RNA sequencing revealed that GAMG significantly affected the changes of macrophage subsets in LF, and Funrich analysis identified IRF1 as a key transcription factor regulating the macrophage genome. IRF1 was significantly increased while ferroptosis related SLC7A11 was significantly down-regulated in GAMG treated inflammatory macrophages. Mass spectrometry metabolomics analysis showed that GAMG significantly affected metabolites associated with LF. In vivo and in vitro experiments further verified that GAMG induced ferroptosis of inflammatory macrophages through the IRF1/SLC7A11 axis, and ultimately alleviated LF. Therefore, GAMG induces ferroptosis of inflammatory macrophages by activating the IRF1/SLC7A11 axis, which provides a new strategy for the treatment of LF.

Fat accumulation is the hallmark of metabolic dysfunction-associated steatotic liver disease (MASLD). Given the intimidating nature of its treatment, curcumin (CUR) emerges as a potential therapeutic agent due to its proven effectiveness in managing MASLD. This review aimed to evaluate previous reports on the hepatoprotective and fat-accumulation-reductive effects of CUR administration in preventing or treating MASLD. CUR administration can modulate serum liver enzymes and lipid profiles. The fat accumulation of MASLD is the primary cause of oxidative stress and inflammation. By reducing fat accumulation, CUR may attenuate the inflammation and oxidative stress in MASLD. In addition, CUR has been proven to restore the dysfunctional cellular energy metabolism capacity and attenuate fibrogenesis (antifibrotic agent). Their hepatoprotective effects are associated with fat accumulation in MASLD. Lipid metabolism (lipogenesis, lipolysis, and lipophagy) is correlated with their hepatoprotective effects. CUR has prophylactic and therapeutic effects, particularly in early-stage MASLD, primarily when it is used as a fat reducer. It can be considered an excellent natural therapeutic drug for MASLD because it protects the liver and attenuates fat accumulation, especially in the early stage of MASLD development.

Background and Objectives: As a key mechanism of metabolic dysfunction-associated steatotic liver disease (MASLD) pathogenesis, inflammation triggered by chronic liver injury and immune cells with macrophages enables MASLD to progress to an advanced stage with irreversible processes such as fibrosis, cell necrosis, and cancer in the liver. The complexity of MASLD, including crosstalk between multiple organs and the liver, makes developing a new drug for MASLD challenging, especially in single-drug therapy. It was reported that upregulation of Notch1 is closely associated with the function of pro-inflammatory macrophages. To leverage this signaling pathway in treating MASLD, we developed a combination therapy. Materials and Methods: We chose Notch1 siRNA (siNotch1) to block the Notch pathway so that phenotypic regulation and functional recovery can be achieved in macrophages, combining with small molecule drug AMD3100. AMD3100 can cut off the migration of inflammatory cells to the liver to impede the development of inflammation and inhibit the CXCL12/CXCR4 biological axis in liver fibrosis to protect against the activation of HSCs. Then, we investigated the efficacy of the combination therapy on resolving inflammation and MASLD. Results: We demonstrated that in liver cells, siNotch1 combined with AMD3100 not only directly modulated macrophages by downregulating multiple pathways downstream of Notch, exerting anti-inflammatory, anti-migration, and switch of macrophage phenotype, but also modulated macrophage phenotypes through inhibiting NET release. The restored macrophages further regulate HSC and neutrophils. In in vivo pharmacodynamic studies, combination therapy exhibits a superior therapeutical effect over monotherapy in MASLD models. Conclusions: These results constitute an siRNA therapeutical approach combined with a small molecule drug against inflammation and liver injury in MASLD, offering a promising therapeutic intervention for MASLD.

The progression of liver fibrosis involves complex interactions between hepatic stellate cells (HSCs) and multiple immune cells in the liver, including macrophages. However, the mechanism of exosomes in the crosstalk between liver macrophages and HSCs remains unclear.

Exosomes were extracted from primary mouse macrophages and cultured with HSCs, and the differential expression of microRNAs was evaluated using high-throughput sequencing technology. The functions of miR-342-3p in exosomes were verified by qPCR and luciferase reporter gene experiments with HSCs. The function of the target gene Hippocalcin-like protein 1 (HPCAL1) in HSCs was verified by Western blotting, qPCR, cellular immunofluorescence and co-IP in vivo and in vitro.

We demonstrated that exosomal microRNA-342-3p derived from primary liver macrophages could activate HSCs by inhibiting the expression of HPCAL1 in HSCs. HPCAL1, which is a fibrogenesis suppressor, could inhibit TGF-β signaling in HSCs by regulating the ubiquitination of Smad2 through direct interactions with its EF-hand 4 domain.

This study reveals a previously unidentified profibrotic mechanism of crosstalk between macrophages and HSCs in the liver and suggests an attractive novel therapeutic strategy for treating fibroproliferative liver diseases.

Liver cirrhosis is prognostically associated with poor life expectancy owing to subsequent liver failure. Thus, understanding liver regeneration processes during cirrhotic injury is highly important. This study explored the role of macrophage heterogeneity in liver regeneration following splenectomy. We collected detailed clinical information from 54 patients with decompensated cirrhosis before and after splenectomy. Obvious liver regeneration was observed after splenectomy in cirrhotic patients. Single-cell RNA sequencing (scRNA-seq) was performed on three paired liver tissues from patients before and after surgery to explore the immune microenvironment map and the characteristics of liver regeneration-associated macrophages (RAMs). scRNA-seq analysis revealed that the composition of hepatic immune cells changed after splenectomy; among these changes, the proportion of CD300E+ RAMs significantly increased after surgery, and high expression levels of functional genes associated with cell proliferation promoted liver regeneration. Moreover, a mouse model of carbon tetrachloride-induced cirrhosis and a coculture system consisting of primary bone marrow-derived macrophages and hepatocytes were established for validation. We observed a similar phenomenon of liver regeneration in cirrhotic mice and further confirmed that CD300E+ monocyte-derived macrophages facilitated hepatocyte NAD+ synthesis via the secretion of NAMPT, which subsequently promoted hepatocyte proliferation. This study characterized the hepatic immune microenvironment in patients with cirrhosis following splenectomy. Our findings demonstrated that CD300E+ macrophages play a crucial role in remodeling the hepatic immune microenvironment after splenectomy, thereby promoting liver regeneration in patients with decompensated cirrhosis. CD300E+ macrophages are anticipated to emerge as a novel therapeutic strategy for the treatment of liver cirrhosis.

Hepatic ischemia/reperfusion injury is a severe clinical condition leading to high mortality as the result of excessive inflammation, partially triggered by released damage-associated molecular patterns. Extracellular cold-inducible RNA-binding protein is a new damage-associated molecular pattern. Current clinical management of hepatic ischemia/reperfusion injury is limited to supportive therapy, necessitating the development of novel and effective treatment strategies. Milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 is a newly invented oligopeptide originating from milk fat globule-epidermal growth factor-VIII. This peptide acts as an opsonic compound that specifically binds to extracellular cold-inducible RNA-binding protein to facilitate its clearance by phagocytes, thereby attenuating inflammation. In this study, we hypothesized that milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 attenuated hepatic ischemia/reperfusion injury by inhibiting extracellular cold-inducible RNA-binding protein-induced inflammation in Kupffer cells.

We treated Kupffer cells isolated from male C57BL/6 mice with extracellular cold-inducible RNA-binding protein and various doses of milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 for 4 hours, then measured cytokines in the culture supernatants. In addition, mice underwent 70% hepatic ischemia for 60 minutes immediately followed by the intravenous administration of either vehicle or milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3. Blood and ischemic liver tissues were collected 24 hours later, and inflammatory markers including cytokines, liver enzymes, chemokines, myeloperoxidase activity, and Z-DNA-binding protein 1 were measured. Hepatic tissue damage and cell death were evaluated histologically. Survival rates were monitored for 10 days posthepatic ischemia/reperfusion.

The release of interleukin-6 and tumor necrosis factor-α from extracellular cold-inducible RNA-binding protein-challenged Kupffer cells was significantly reduced by milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 in a dose-dependent manner. In hepatic ischemia/reperfusion mice, milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 treatment significantly decreased serum levels of extracellular cold-inducible RNA-binding protein, interleukin-6, tumor necrosis factor-α, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase. Milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 treatment also significantly reduced mRNA levels of interleukin-6, tumor necrosis factor-α, interleukin-1β, Z-DNA-binding protein 1, and chemokine macrophage inflammatory protein-2, as well as myeloperoxidase activity in hepatic tissues. Histologic evaluation demonstrated that treatment with milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 significantly attenuated tissue damage and cell death in the liver of hepatic ischemia/reperfusion mice. Milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 treatment significantly improved the survival rate of hepatic ischemia/reperfusion mice.