The aspartate aminotransferase-to-platelet ratio index (APRI) is an effective non-invasive marker for chronic liver dysfunction. Given that heat stroke patients often suffer from poor prognosis due to multi-organ involvement, with liver injury and coagulation dysfunction being of particular concern, this study aims to investigate whether APRI can comprehensively reflect liver injury and coagulation dysfunction in heat stroke patients and explore its relationship with 28-day mortality.

This retrospective study analysed electronic medical records from patients treated at 57 grade A tertiary hospitals in China from May 2005 to May 2024. The primary outcome was 28-day mortality, and the secondary outcome was 7-day mortality. Restricted cubic splines (RCS) were utilized to visualize the relationship between APRI and 28-day mortality risk. The independent association between APRI and outcomes was assessed using Cox proportional hazards models, with multivariable analyses controlling for confounding factors. The predictive ability of APRI for outcomes was evaluated using receiver operating characteristic (ROC) curves.

A total of 450 eligible patients were included, with 71 deaths occurring within 28 days. RCS analysis showed a positive correlation between APRI and 28-day mortality. Participants were divided into higher (APRI ≥ 15.14) and lower (APRI < 15.14) APRI groups. Cox proportional hazards models indicated that individuals with higher APRI had a significantly increased 28-day mortality rate (HR 5.322, 95% confidence interval [CI] 2.642-10.720, p < 0.0001). Subgroup and interaction analyses confirmed the robustness of the core findings. Additionally, the areas under the ROC (AUROC) for APRI predicting 28-day mortality was 0.823 (95% CI 0.772-0.875), significantly higher than the AST to ALT ratio (0.526, 95% CI 0.448-0.605) and total bilirubin (0.694, 95% CI 0.623-0.765).

APRI is an independent predictor of early mortality risk in heat stroke.

Metabolic Associated Steatotic Liver Disease (MASLD), encompassing conditions simple liver steatosis (MAFL) and metabolic associated steatohepatitis (MASH), is the most prevalent chronic liver disease. Currently, the management of MASLD is impeded by the lack of reliable diagnostic biomarkers and effective therapeutic strategies.

We analyzed eight independent clinical MASLD datasets from the GEO database. Differential expression and weighted gene co-expression network analyses (WGCNA) were used to identify 23 genes related to inflammation. Five hub genes were selected using machine learning techniques (SVM-RFE, LASSO, and RandomForest) combined with a literature review. Nomograms were created to predict MASLD incidence, and the diagnostic potential of the hub genes was evaluated through receiver operating characteristic (ROC) curves. Additionally, Protein-Protein Interaction (PPI) networks, functional enrichment, and immune infiltration analyses were performed. Potential transcription factors and therapeutic agents were also explored. Finally, the expression and biological significance of these hub genes were validated using MASLD animal model, histological examination and transcriptomic profiles.

We identified five hub genes-UBD/FAT10, STMN2, LYZ, DUSP8, and GPR88-that are potential biomarkers for MASLD. These genes exhibited strong diagnostic potential, either individually or in combination.

This study highlights five key biomarkers as promising candidates for understanding MASLD. These findings offer new insights into the disease's pathophysiology and may contribute to the development of better diagnostic and therapeutic approaches.

Upon metastatic seeding in the liver, liver macrophages, including Kupffer cells, acquire a transcriptional profile typical of tumor-associated macrophages (TAMs), which support tumor progression. MicroRNAs (miRNAs) fine-tune TAM pro-tumoral functions, making their modulation a promising strategy for macrophage reprogramming into an anti-tumoral phenotype. Here, we analyze the transcriptomic profiles of liver and splenic macrophages, identifying miR-342-3p as a key regulator of liver macrophage function. miR-342-3p is highly active in healthy liver macrophages but significantly downregulated in colorectal cancer liver metastases (CRLMs). Lentiviral vector-engineered liver macrophages enforcing miR-342-3p expression acquire a pro-inflammatory phenotype and reduce CRLM growth. We identify Slc7a11, a cysteine-glutamate antiporter linked to pro-tumoral activity, as a direct miR-342-3p target, which may be at least partially responsible for TAM phenotypic reprogramming. Our findings highlight the potential of in vivo miRNA modulation as a therapeutic strategy for TAM reprogramming, offering an approach to enhance cancer immunotherapy.

Activated hepatic stellate cells (HSCs) induce alternative (M2) polarization of macrophages and contribute to the progression of fibrosis and hepatocellular carcinoma (HCC). However, the effects of small extracellular vesicles released by HSCs (HSC-sEVs) during activation remain largely unknown.

The aim of this study was to investigate the role of extracellular vesicles released by HSCs (HSC-sEVs) at different stages of activation in macrophage polarization. The effects of sEVs from short-term activated and long-term activated HSCs on liver macrophages was studied. Small RNA sequencing analyses were performed to obtain differential miRNAs transported by the short-term and long-term activated HSC- sEVs. The in vivo effects of short-term activated HSC-sEV-specific miRNA on liver macrophage and liver fibrosis were confirmed in a CCl4-induced liver injury mouse model. To study the tumor suppressive effects of the macrophages educated by short-term activated HSC-sEV-specific miRNA, human hepatoma cells were mixed and subcutaneously cotransplanted with miR-99a-5p mimic-pretreated macrophages.

We found that consistent with activated HSCs, long-term activated HSC-sEVs (14dHSC-sEVs) induce bone marrow-derived monocytes (MOs) toward an M2 phenotype, but short-term activated HSC-sEVs (3dHSC-sEVs) induce the resident macrophages (Kupffer cells, KCs) toward a classically activated (M1) phenotype. We identified five 3dHSC-sEV-specific miRNAs, including miR-99a-5p. In vitro and in vivo experiments support that miR-99a-5p negatively regulates alternative polarization of macrophages, decreases collagen deposition in chronic liver injury model, and suppresses the progression of hepatoma in a xenograft model partially by targeting CD93.

Collectively, our work reveals an unexpected proinflammatory role of 3dHSC-sEVs, preliminarily explores the underlying mechanism, and evaluates the therapeutic potential of 3dHSC-sEV-specific miR-99a-5p for liver fibrosis and tumorigenesis.

Hepatitis B virus (HBV) infection is a global public health challenge that alters the immune microenvironment of the liver and drives disease progression by triggering chronic inflammation that leads to hepatic cell death through multiple programmed cell death (PCD) modalities. Due to the persistence of covalently closed circular DNA in hepatocytes, there is a lack of curative drugs that can completely eradicate HBV. Therefore, revealing how HBV infection leads to changes in the hepatic immune microenvironment, as well as searching for specific molecular targets, is crucial for controlling the onset and progression of chronic hepatitis B (CHB). In this study, we used the single sample gene set enrichment analysis and CIBERSORT algorithms to assess immune cell infiltration in the livers of CHB patients. With three advanced machine learning algorithms, random forest, least absolute shrinkage and selection operator, and selected support vector machine recursive feature elimination, we identified the PCD signature genes associated with CHB from the candidate genes. We further validated that ubiquitin-specific peptidase 21 could differentiate CHB patients with different natural courses by receiver operating characteristic analysis. These findings enhance our understanding of the mechanisms of HBV infection.

Acetaminophen (APAP) is safe at therapeutic doses; however, when ingested in excess, it accumulates in the liver and leads to severe hepatotoxicity, which in turn may trigger acute liver failure (ALF). This is known as APAP poisoning and is a major type of drug‑related liver injury. In the United States, APAP poisoning accounts for ≥50% of the total number of ALF cases, making it one of the most common triggers of ALF. According to the American Association for the Study of Liver Diseases, the incidence of APAP‑associated hepatotoxicity has increased over the past few decades; however, the mechanism underlying liver injury due to APAP poisoning has remained inconclusive. The present study aims to comprehensively review and summarize the latest research progress on the mechanism of APAP‑induced liver injury, and to provide scientific and effective guidance for the clinical treatment of APAP poisoning through in‑depth analysis of the metabolic pathways, toxicity‑producing mechanisms and possible protective mechanisms of APAP in the liver.

Pyroptosis, a distinctive form of programmed cell death orchestrated by gasdermin proteins, manifests as cellular rupture, accompanied by the release of inflammatory factors. While pyroptosis is integral to anti-infection immunity, its aberrant activation has been implicated in tumorigenesis. The liver, as the body's largest metabolic organ, is rich in various enzymes and governs metabolism. It is also the primary site for protein synthesis. Recent years have witnessed the emergence of pyroptosis as a significant player in the pathogenesis of specific liver diseases, exerting a pivotal role in both physiological and pathological processes. A comprehensive exploration of pyroptosis can unveil its contributions to the development and regression of conditions such as hepatitis, cirrhosis, and hepatocellular carcinoma, offering innovative perspectives for clinical prevention and treatment. This review consolidates current knowledge on key molecules involved in cellular pyroptosis and delineates their roles in liver diseases. Furthermore, we discuss the potential of leveraging pyroptosis as a novel or existing anti-cancer strategy.

Myocarditis, an inflammatory disease of the heart muscle, is often triggered by viral infections. This inflammation, which can lead to severe cardiac dysfunction and adverse outcomes, is mediated by various CC and CXC chemokines that interact with receptors in a "one-to-many" fashion. Ticks have evolved chemokine-binding salivary proteins known as Evasins, which efficiently suppress inflammation. This study explores a tailored Evasin-derived CC chemokine-targeting strategy using a 17-mer synthetic dimeric peptide, BK1.3. This peptide inhibits the inflammatory chemokines CCL2, CCL3, CCL7, and CCL8 in murine Coxsackievirus B3 (CVB3) infection, a viral trigger of myocarditis. Administered at a dose of 5 mg/kg twice daily, BK1.3 effectively maintains virus control without exacerbating CVB3-induced morbidity markers, such as hemodynamic compromise, multiorgan failure with hepatitis and pancreatitis, hypothermia, hypoglycemia, and weight loss. Metabolic profiling combined with proteomics reveals preserved reprogramming of lipid storage and gluconeogenesis capacity in the liver, alongside sustained energy production in the injured heart muscle. In survivors of acute CVB3 infection exhibiting manifestations of the subacute phase, BK1.3 enhances virus control, reduces myeloid cell infiltration in the heart and liver, improves markers of liver injury, and alleviates cardiac dysfunction, as evidenced by echocardiographic global longitudinal strain analysis. These findings affirm the safety profile of BK1.3 peptide therapeutics in a preclinical mouse model of acute CVB3 infection and emphasize its potential for therapeutic advancement in addressing virus-induced inflammation in the heart.

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become the most common chronic liver disease globally. MASLD is a multisystem disease where metabolic dysfunction plays a key role in the development of MASLD and its most relevant liver-related morbidities and extrahepatic complications, such as cardiovascular disease, chronic kidney disease and certain types of extrahepatic cancers. Among the least examined MASLD-related extrahepatic complications, an ever-increasing number of observational studies have reported a positive association between MASLD and the risk of serious bacterial infections (SBI) requiring hospital admission. This risk remained significant in those studies where statistical analysis was adjusted for age, sex, ethnicity, obesity, type 2 diabetes and other common comorbidities. Notably, the incidence rates of SBI were further increased with more advanced MASLD, especially in patients with MASLD-related cirrhosis, and were also observed for some acute viral infections, including SARS-CoV-2 infection, leading to severe COVID-19. In this narrative review article, we provide an overview of the literature on (a) the recent epidemiological data linking MASLD to the risk of serious bacterial and non-bacterial infections requiring hospital admission, (b) the putative underlying mechanisms through which MASLD may increase the susceptibility to serious infections, both directly and through the immune dysfunction associated with cirrhosis and portal hypertension, and (c) the practical and clinical implications of the increased risk of serious bacterial and non-bacterial infections in the growing global population with MASLD.

Mitochondrial oxysterols, cholestenoic acid (CA), 25-hydroxycholesterol (25HC), and 27-hydroxycholesterol (27HC), are potent regulators involved in many important biological events. This study aimed to investigate the metabolic pathways of these oxysterols and their roles between hepatocytes and macrophages. LC-MS/MS analysis showed a novel regulatory molecule, 3β-sulfate-5-cholestenoic acid (3SCA), following the addition of CA in media culturing hepatocytes. Further study showed that 3SCA could also be derived from 27HC. In comparison, 25HC was converted to 25HC3S, which mostly remained in the cells and nuclei. The functional study showed that 3SCA significantly downregulated the expression of genes involved in lipid metabolism in hepatocytes and suppressed gene expression of proinflammatory cytokines induced by lipopolysaccharide in human macrophages. Based on the results, we conclude that 3SCA acts as a secretory regulator for the regulation of lipid metabolism and inflammatory responses in hepatocytes and macrophages. These findings shed light on understanding the unique metabolic pathways of these oxysterols and their possible roles in liver tissues.NEW & NOTEWORTHY This study identifies a novel oxysterol metabolite, 3β-sulfate-5-cholestenoic acid (3SCA), secreted by hepatocytes, which regulates lipid metabolism and inflammatory responses in hepatocytes and macrophages. These findings reveal previously unknown metabolic pathways of mitochondrial oxysterols and their roles in the progression and recovery of metabolic dysfunction-associated steatotic liver disease (MASLD), offering novel insights into potential therapeutic targets.

Our aim was to explore the IL-27 effect in sepsis (SP)-related acute hepatic injury (AHI) as well as its possible mechanism.

Herein, we utilized both wild-type (WT) and IL-27 receptor (WSX-1)-deficient (IL-27R-/-) mice alongside RAW264.7 cells. Our study established an SP-associated AHI model through the intraperitoneal injections of lipopolysaccharide (LPS) + D-galactosamine (D-G). For examining the IL-27 impact on AHI, mice serum and liver tissue samples were gathered. Inflammatory factor levels in the liver and serum were detected using ELISA and immunohistochemistry. Immunofluorescence and Western blot techniques were employed for the detection of protein expression associated with polarization and pyroptosis in the liver, including iNOS, ARG-1, caspase-11, RAGE, and GSDMD. To further verify the IL-27 effects on macrophage polarization and pyroptosis and explore possible mechanisms involved, we used LPS-triggered RAW264.7 macrophages to assess AMPK/SIRT1 expression after IL-27 intervention. This study utilized Compound C (CC) to block the AMPK/SIRT1 pathway. The inflammatory response level and protein expression related to macrophage polarization and pyroptosis were measured again to reveal IL-27 implication in AHI and determine whether its role is associated with the AMPK/SIRT1 pathway.

The results revealed that IL-27 exacerbated systemic inflammation and liver damage in AHI mice by promoting M1 macrophage polarization, thereby increasing pro-inflammatory phenotype macrophages (M1). This further exacerbated the inflammatory response and pyroptosis in vivo and in vitro. Additionally, IL-27 down-regulated p-AMPK and SIRT1 protein expression while overexpressing macrophage inflammatory mediators including IL-1β/6 and TNFα. Furthermore, IL-27 promoted increased RAGE and caspase-11 protein expression, aggravating macrophage pyroptosis. Employing CC to block the AMPK pathway further aggravated M1 macrophage polarization and pyroptosis in vitro and in vivo, ultimately worsening liver injury.

Here, IL-27 aggravates AHI by promoting macrophage M1 polarization to induce caspase-11-mediated pyroptosis in vitro and in vivo, which may be linked to the AMPK/SIRT1 signaling pathway.

Hepatic ischemia-reperfusion injury (IRI) is an inevitable adverse event following liver surgery, leading to liver damage and potential organ failure. Despite advancements, effective interventions for hepatic IRI remain elusive, posing a significant clinical challenge. The innate immune response significantly contributes to the pathogenesis of hepatic IRI by promoting an inflammatory cytotoxic cycle. We have reported that blocking GSDMD-induced pyroptosis in innate immunity cells protected hepatic IRI from inflammatory injury. However, the search for effective pyroptosis inhibitors continues.

This study aims to evaluate whether quercetin, a natural flavonoid, can inhibit GSDMD-induced pyroptosis and mitigate hepatic IRI.

We established the hepatic IRI murine model and cellular pyroptosis model to evaluate the efficacy of quercetin.

Quercetin effectively alleviated hepatic IRI-induced tissue necrosis and inflammation. We found that during hepatic IRI, the cleavage of GSDMD occurred in hepatic macrophages, but not in other non-parenchymal cells. Quercetin inhibited the cleavage of GSDMD in macrophages. Moreover, we found that quercetin blocked the ASC assembly to inhibit the formation of NLRP3 inflammasomes and AIM2 inflammasomes, suppressing macrophage pyroptosis. Co-immunoprecipitation experiments confirmed that quercetin inhibited the interaction between ASC and Caspase-8, which is the mechanism of ASC complex and inflammasome formation. Overexpression of Caspase-8 abolished the anti-pyroptosis effect of quercetin in NLRP3 and AIM2 inflammasome signaling. Furthermore, we found that the hepatoprotective activity of quercetin was reduced in myelocytic GSDMD-deficient mice.

Our findings suggest that quercetin has beneficial effects on hepatic IRI. Quercetin could attenuate hepatic IRI and target inhibition of macrophage pyroptosis via blocking Caspase-8/ASC interaction. We recommend that quercetin might serve as a targeted approach for the prevention and personalized treatment of hepatic IRI in perioperative patients.

Scutellaria barbata is a medicinal plant with anti-inflammatory, antioxidant, and antitumor properties. Limited studies exist on the link between S. barbata and liver fibrosis. The focus of this study is to examine the impact of S. barbata-containing serum on rat hepatocytes undergoing hepatic fibrosis. Molecular mechanisms underlying the observed effects are sought to be predicted. Transforming growth factor β1 (TGF-β1)-treated hepatic stellate cells (HSCs) supernatant was utilized to produce hepatic fibrosis-like conditions in hepatocytes BRL-3A cultured in vitro. S. barbata-containing serum was used as an intervention, with various dosage groups and a positive drug group (N-acetylcysteine). Cell proliferation, mitochondrial membrane potential (MMP), apoptosis, and expression of apoptosis-related proteins and genes were assessed through various assays and techniques. Bioinformatics analysis was employed to predict target genes and signaling pathways affected by S. barbata. Chemical components of S. barbata in the serum were detected by ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-QE-MS) was used to identify. Cellular experiments demonstrated that S. barbata-containing serum restored cell proliferation and reduced apoptotic activity induced by the fibrosis model, with a significant downregulation of apoptosis-related proteins (cleaved-Caspase-3, Bax), a substantial upregulation of the anti-apoptotic protein BCL-2, and a substantial elevation in the level of cellular MMP. Bioinformatics analysis highlighted the involvement of S. barbata in hepatocyte apoptosis during liver fibrosis, possibly through pathways like PI3K-Akt. UHPLC-QE-MS identified 29 chemical components of S. barbata in the bloodstream, suggesting their role in anti-hepatic fibrosis effects. S. barbata was found to effectively inhibit hepatocyte apoptosis during hepatic fibrosis.

Liver fibrosis is a chronic liver injury resulting from factors like viral hepatitis, autoimmune hepatitis, non-alcoholic steatohepatitis, fatty liver disease, and cholestatic liver disease. Liver transplantation is currently the gold standard for treating severe liver diseases. However, it is limited by a shortage of donor organs and the necessity for lifelong immunosuppressive therapy. Mesenchymal stem cells (MSCs) can differentiate into various liver cells and enhance liver function when transplanted into patients due to their differentiation and proliferation capabilities. Therefore, it can be used as an alternative therapy for treating liver diseases, especially for liver cirrhosis, liver failure, and liver transplant complications. However, due to the potential tumorigenic effects of MSCs, researchers are exploring a new approach to treating liver fibrosis using extracellular vesicles (exosomes) secreted by stem cells. Many studies show that exosomes released by stem cells can promote liver injury repair through various pathways, contributing to the treatment of liver fibrosis. In this review, we focus on the molecular mechanisms by which stem cell exosomes affect liver fibrosis through different pathways and their potential therapeutic targets. Additionally, we discuss the advantages of exosome therapy over stem cell therapy and the possible future directions of exosome research, including the prospects for clinical applications and the challenges to be overcome.

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.

Hepatic ischemia-reperfusion injury (HIRI) is an essential clinical concern caused by liver transplantation, resection, trauma, and shock that must be addressed immediately. Although the mechanisms underlying HIRI are well-documented, effective prevention and treatment strategies are still lacking. Inflammation is a central mechanism of HIRI, with macrophages playing a crucial role in initiating and amplifying the inflammatory response. Numerous plant polysaccharides exhibit substantial anti-inflammatory and hepatoprotective properties. However, the function of Lentinan (LNT) in HIRI has not been fully explored. Thus, this study aims to investigate the preventive potential of LNT in HIRI. Here, we reveal that oral administration of LNT considerably reduces hepatic inflammation and improves liver pathology in mice with HIRI by modulating gut microbiota. Specifically, LNT considerably increased microbiota-derived isoursodeoxycholic acid (IsoUDCA). Further experiments showed that IsoUDCA alleviates hepatic injury by suppressing macrophage inflammation. Mechanistically, IsoUDCA directly binds to and activates the neuron-derived clone 77 (Nur77) transcription factor, inhibiting the NF-κB signaling pathway in macrophages. Our findings shed light on the significant role of the LNT-microbiota-IsoUDCA-Nur77 axis in attenuating macrophage inflammation during HIRI, offering novel insights into potential therapeutic targets and avenues for preventing HIRI.

In murine models of visceral leishmaniasis (VL), the parasitization of resident Kupffer cells (resKCs) drives early Leishmania infantum growth in the liver, leading to granuloma formation and subsequent parasite control. Using the chronic VL model, we demonstrate that polyclonal resKCs redistributed to form granulomas outside the sinusoids, creating an open sinusoidal niche that was gradually repopulated by monocyte-derived KCs (moKCs) acquiring a tissue specific, homeostatic profile. Early-stage granulomas predominantly consisted of CLEC4F+KCs. In contrast, late-stage granulomas led to remodeling of the sinusoidal network and contained monocyte-derived macrophages (momacs) along with KCs that downregulated CLEC4F, with both populations expressing iNOS and pro-inflammatory chemokines. During late-stage infection, parasites were largely confined to CLEC4F-KCs. Reduced monocyte recruitment and increased resKCs proliferation in infected Ccr2-/- mice impaired parasite control. These findings show that the ontogenic heterogeneity of granuloma macrophages is closely linked to granuloma maturation and the development of hepatic immunity in VL.

Liver regeneration after hepatectomy follows accurate coordination with the body's specific requirements1-3. However, the molecular mechanisms, factors and particular hepatocyte population influencing its efficiency remain unclear. Here we report on a unique regeneration mechanism involving unconventional RPB5 prefoldin interactor 1 (URI1), which exclusively colocalizes with, binds to and activates glutamine synthase (GS) in pericentral hepatocytes. Genetic GS or URI1 depletion in mouse pericentral hepatocytes increases circulating glutamate levels, accelerating liver regeneration after two-third hepatectomy. Conversely, mouse hepatocytic URI1 overexpression hinders liver restoration, which can be reversed by elevating glutamate through supplementation or genetic GS depletion. Glutamate metabolically reprograms bone-marrow-derived macrophages, stabilizing HIF1α, which transcriptionally activates WNT3 to promote YAP1-dependent hepatocyte proliferation, boosting liver regeneration. GS regulation by URI1 is a mechanism that maintains optimal glutamate levels, probably to spatiotemporally fine-tune liver growth in accordance with the body's homeostasis and nutrient supply. Accordingly, in acute and chronic injury models, including in cirrhotic mice with low glutamate levels and in early mortality after liver resection, as well as in mice undergoing 90% hepatectomy, glutamate addition enhances hepatocyte proliferation and survival. Furthermore, URI1 and GS expression co-localize in human hepatocytes and correlate with WNT3 in immune cells across liver disease stages. Glutamate supplementation may therefore support liver regeneration, benefiting patients awaiting transplants or recovering from hepatectomy.

Liver fibrosis is caused by liver injury resulting from the wound healing response. According to recent research, the primary factor responsible for liver fibrosis is the activation of hepatic stellate cells (HSCs). C-C motif chemokine ligand 1 (CCL1) is one of several chemokine genes clustered on chromosome 17, which is involved in immune regulation and inflammatory processes. However, the role of CCL1 in liver fibrosis has not been reported. We found that CCL1 secreted by macrophages can target and activate the receptor protein C-C motif chemokine receptor 8 (CCR8) of HSCs, accelerating liver fibrosis progression by activating the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signalling pathway. This suggested that the CCL1-mediated regulation of CCR8 is an important event in liver fibrosis progression. In conclusion, this study identified a novel signalling axis, the CCL1/CCR8/JAK/STAT pathway, which regulates the activation and apoptosis of HSCs, thus providing a novel therapeutic strategy for liver fibrosis.

Invasive infections by encapsulated bacteria are the major cause of human morbidity and mortality. The liver resident macrophages, Kupffer cells, form the hepatic firewall to clear many encapsulated bacteria in the blood circulation but fail to control certain high-virulence capsule types. Here we report that the spleen is the backup immune organ to clear the liver-resistant serotypes of Streptococcus pneumoniae (pneumococcus), a leading human pathogen. Asplenic mice failed to control the growth of the liver-resistant pneumococci in the blood circulation. Immunologic and genetic analyses identified splenic red pulp (RP) macrophages as the major phagocytes for bacterial clearance. Furthermore, the plasma natural antibodies against the cell wall phosphocholine and the complement system were necessary for RP macrophage-mediated immunity. These findings have provided a conceptual framework for the innate defense against blood bacterial infections, a mechanistic explanation for the hyper-susceptibility of asplenic individuals to S. pneumoniae, and a proof of concept for developing vaccines and therapeutic antibodies against encapsulated pathogens.

The rising prevalence of autoimmune hepatitis (AIH) and its intricate pathogenesis has escalated it to a global health issue. This study centered on investigating the effects of allyl methyl disulfide (AMDS) against concanavalin A (ConA)-induced AIH in mice and elucidate the possible mechanisms. Histopathology and blood biochemistry were performed to assess the protective effects of AMDS on ConA-challenged liver injury in C57BL/6 male mice. Then, Immunohistochemistry, Immunofluorescence, RT-qPCR, ELISA and Western blot assays were performed to test changes in the M1 polarization of macrophage and NLRP3 inflammasome activation. Additionally, J774A.1 and AML12 cells were co-cultured to further investigate protective mechanism of AMDS against AIH. We found that AMDS pretreatment significantly alleviated the elevation of the levels of liver injury marker enzymes, and liver pathological changes triggered by ConA. Additionally, AMDS antagonized liver neutrophil infiltration, liver macrophage M1 polarization, and the increase in serum IL-6 and TNF-α levels induced by ConA. Furthermore, the changes in protein and mRNA levels of crucial molecules in the NF-κB and NLRP3 inflammasome pathways after ConA challenge were restored by AMDS. Additionally, AMDS significantly ameliorated the ConA-induced morphological alterations, the release of IL-6 and TNF-α, and the activation of NLRP3 inflammasome pathway in J774A.1 macrophages. Lastly, in a conditioned co-culture system of AML12 and J774A.1 cells, administration of AMDS at a concentration of 25 μM prominently inhibited the mRNA levels of Tnf and Nos2 in AML12 cells. Collectively, AMDS ameliorates ConA-induced AIH by alleviating hepatic neutrophil infiltration, inhibiting M1-type macrophage polarization, and antagonizing NLRP3 inflammasome activation.

Sepsis is a complex clinical syndrome closely associated with the occurrence of acute organ dysfunction and is often characterized by high mortality. Due to the rapid progression of sepsis, early diagnosis and intervention are crucial. Recent research has focused on exploring the pathological response involved in the process of sepsis. Liver sinusoidal endothelial cells (LSECs) are a special type of endothelial cell and an important component of liver non-parenchymal cells. Unlike general endothelial cells, which mainly provide a barrier function within the body, LSECs also have important functions in the clearance and regulation of the immune response. LSECs are not only vital antigen-presenting cells (APCs) in the immune system but also play a significant role in the development of infectious diseases and tumors through their specific immune regulatory pathways. However, in certain disease states, the functions of LSECs may be impaired, leading to immune imbalance and the development of organ failure. Investigating the immune pathways of LSECs in sepsis may provide new solutions for the prevention and treatment of sepsis and is crucial for maintaining microcirculation and improving patient outcomes.

Chronic liver diseases (CLDs) in dogs are progressive conditions that often lead to liver failure. Metabolic dysfunctions such as cholestasis, obesity, hyperlipidemia, and endocrine disorders play a key role in human liver diseases like MASLD (Metabolic Dysfunction Associated Steatotic Liver Disease) and MASH (Metabolic Dysfunction Associated Steatohepatitis), but their significance in canine CLDs is poorly understood. This study aims to evaluate the association between hepatic lipid accumulation and inflammation or fibrosis in canine CLDs and its potential association with metabolic dysfunctions. Sixteen client-owned dogs with CLDs were assessed for clinical data, histological features, and liver immunohistochemistry (IHC). Histological and IHC markers of inflammation (Iba-1, iNOS, NF-κB), fibrosis (CD206, α-SMA, Sirius Red), and lipid accumulation (adipophilin) were assessed to identify correlations with clinical conditions. The applied markers showed effectiveness in their use on canine liver tissue. Adipophilin-marked lipid accumulation correlated positively with inflammatory markers, indicating a link between steatosis and inflammation. Metabolic dysfunctions were linked to hepatic lipid accumulation and inflammation. These findings show a potential alignment of canine CLDs with human MASLD/MASH, where lipid-induced inflammation drives disease progression. IHC markers could effectively assess these processes, suggesting potential for guiding diagnostics and therapies, though further research is needed to clarify clinical associations.

Macrophage polarization has been linked to hepatotoxicity induced by raw Polygonum multiflorum (RPM) and Polygonum multiflorum praeparata (PMP), but the regulatory mechanisms behind this remain unclear. This study aims to investigate the regulatory effects of RPM and PMP on M2 macrophages and the potential mechanisms. Sprague-Dawley rats were exposed to RPM and PMP under lipopolysaccharide (LPS) stimulation. RAW264.7 cells induced with IL-4 were treated with RPM and PMP. Under LPS stimulation, both RPM and PMP increased serum enzyme levels and pro-inflammatory factor levels and induced histopathological injury. M1 macrophage infiltration and M1 gene expression in the liver increased, whereas M2 macrophage infiltration and M2 gene expression decreased. RPM and PMP inhibited M2 gene expression and reduced green fluorescence intensity. RNA sequencing and metabolomics revealed that RPM regulated sphingolipid signaling and Janus kinase/signal transducer and activator of transcription signaling pathways, while PMP influenced arginine and proline metabolism, arginine biosynthesis, and cholesterol metabolism pathways. RPM and PMP orchestrate distinct signaling pathways, thereby inhibiting M2 macrophage polarization and inducing hepatotoxicity. This study not only elucidates the pathophysiology underlying RPM- and PMP-induced hepatotoxicity, but also provides insights for the development of new therapeutic interventions.

Hepatic fibrosis (HF) is a pathological process in many liver diseases, which lack of specific agents. Pirfenidone (PFD) derivatives are potential new drug. The purpose of this study was to investigate the effect and immunological mechanism of PFD derivatives on HF. A total of 11 PFD derivatives were designed, synthesized and screened. 1-benzyl-6-nitro-4-phenyl-4-(methoxycarbonyl)-2(1 H)-pyridinone (code: Compound 5) had optimal effect on inhibiting nitric oxide release, hepatic stellate cells (HSCs) and T cell proliferation, which suggested that Compound 5 showed anti-inflammatory, anti-fibrosis and immunoregulation effects. Compound 5 inhibited the proliferation of HSC-T6 and T cell in dose-dependent manner, the IC50 was 10.19 μM and 17.16 μM, respectively. Compound 5 inhibited the differentiation of CD8+T cells and promoted the differentiation of Tregs in the splenic T lymphocyte of CCl4-induced mouse HF model. Besides, Compound 5 promoted HSC-T6 apoptosis in dose-dependent manner, accompanied by the down-regulation of α-smooth muscle actin (α-SMA) and collagen-I (Col-I). In terms of mechanism, Compound 5 had no significant effect on glucose uptake of T cells. But it inhibited non-esterified fatty acid (NEFA) secretion of T cell by inhibiting the phosphorylation of PI3K-AKT-mTOR signal, which related to the metabolism of T cell. Subsequently, Compound 5 affected α-SMA and Col-I expression of HSC-T6 by T cell modulating in cell co-culture. CONCLUSION: Compound 5 is a promising new drug against HF by the dual role of inhibiting HSCs and modulating T cells lipid metabolism, which affects the immune microenvironment of HF.

The introduction of immunotherapy (IT) has transformed clinical care of patients with metastatic melanoma. However, many patients still die as a result of progressive disease. Here we analyzed how IT improved survival in a real-world setting. Additionally, we investigated whether IT alters the dynamics and pattern of metastatic progression in different organs resulting from tissue-specific immune microenvironments.

We retrospectively compared a group of 61 patients with metastatic melanoma (24 female, 37 male) treated with IT between 2015 and 2018 with a historical control group of 56 patients with metastatic melanoma (21 female, 35 male) treated with chemotherapy between 2005 and 2008 regarding treatment response rates and overall survival as well as the timing and distribution of metastatic progression.

Patients with metastatic melanoma treated with IT showed increased response rates and longer overall survival when compared with patients treated with chemotherapy. In addition, treatment with IT altered the dynamics but not the pattern of metastatic progression when compared with treatment with chemotherapy. Interestingly, patients receiving IT lived significantly longer after metastatic progression to lymph nodes, lungs and brain, but not after metastatic progression to the liver.

Our results confirm the efficacy of IT in a real-world setting. The altered dynamics of metastases supports studies suggesting a unique role of immune privilege in the liver tissue microenvironment that increases resistance to immunotherapy.

Metabolic dysfunction-associated steatotic liver disease (MASLD; formerly known as nonalcoholic fatty liver disease) is a chronic liver disease affecting over a billion individuals worldwide. MASLD can gradually develop into more severe liver pathologies, including metabolic dysfunction-associated steatohepatitis (MASH), cirrhosis, and liver malignancy. Notably, although being a global health problem, there are very limited therapeutic options against MASLD and its related diseases. While a thyroid hormone receptor agonist (resmetirom) is recently approved for MASH treatment, other efforts to control these diseases remain unsatisfactory. Given the projected rise in MASLD and MASH incidence, it is urgent to develop novel and effective therapeutic strategies against these prevalent liver diseases. In this article, the pathogenic mechanisms of MASLD and MASH, including insulin resistance, dysregulated nuclear receptor signaling, and genetic risk factors (eg, patatin-like phospholipase domain-containing 3 and hydroxysteroid 17-β dehydrogenase-13), are introduced. Various therapeutic interventions against MASH are then explored, including approved medication (resmetirom), drugs that are currently in clinical trials (eg, glucagon-like peptide 1 receptor agonist, fibroblast growth factor 21 analog, and PPAR agonist), and those failed in previous trials (eg, obeticholic acid and stearoyl-CoA desaturase 1 antagonist). Moreover, given that the role of gut microbes in MASLD is increasingly acknowledged, alterations in the gut microbiota and microbial mechanisms in MASLD development are elucidated. Therapeutic approaches that target the gut microbiota (eg, dietary intervention and probiotics) against MASLD and related diseases are further explored. With better understanding of the multifaceted pathogenic mechanisms, the development of innovative therapeutics that target the root causes of MASLD and MASH is greatly facilitated. The possibility of alleviating MASH and achieving better patient outcomes is within reach. SIGNIFICANCE STATEMENT: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease worldwide, and it can progress to more severe pathologies, including steatohepatitis, cirrhosis, and liver cancer. Better understanding of the pathogenic mechanisms of these diseases has facilitated the development of innovative therapeutic strategies. Moreover, increasing evidence has illustrated the crucial role of gut microbiota in the pathogenesis of MASLD and related diseases. It may be clinically feasible to target gut microbes to alleviate MASLD in the future.

As an important component of the cell wall of Gram-negative bacteria, lipopolysaccharide (LPS) is an important inducer of inflammation in humans. Smilax china L. is known for its diverse bioactive functions, particularly its anti-inflammatory effects.

This study aimed to investigate the bioactive function of Smilax china L. polyphenols (SCLP) on LPS-induced inflammation.

Inflammation in RAW264.7 macrophages and mice were induced using LPS. The cytotoxicity of SCLP was investigated by MTT assay. Inflammatory factors were detected by ELISA and RT-PCR. The expression of NF-κB pathway-related proteins was analyzed by Western Blotting.

The results demonstrated that SCLP significantly reduced the levels of pro-inflammatory factors (TNF-α, IL-1β, and IL-6) and inhibited M1 polarization of macrophages in both RAW264.7 macrophages and mice (p < 0.05). Western Blotting analysis revealed that the levels of NF-κB signaling pathway-associated proteins (p-p65, p-IKB, p-IKK) were significantly reduced (p < 0.05). Notably, SCLP significantly downregulated the expression of pro-apoptotic proteins, while upregulating the expression of anti-apoptotic proteins in RAW264.7 macrophages (p < 0.05). Additionally, the levels of antioxidant enzymes were enhanced in mice, suggesting a potential reduction in the inflammatory response.

These findings indicated that SCLP might inhibit LPS-induced M1 polarization through the NF-κB signaling pathway, thereby reducing inflammation. Consequently, SCLP might serve as a promising bioactive substance for preventing inflammation-related injury.

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.

Acute liver failure (ALF) has a high mortality rate, and despite treatment advancements, long-term outcomes remain poor.

This study explores the therapeutic targets and pathways of Sini Decoction plus Ginseng Soup (SNRS) in ALF using bioinformatics and network pharmacology, focusing on its impact on macrophage polarization through glucose metabolism reprogramming. The efficacy of SNRS was validated in an LPS/D-GalN-induced ALF model, and its optimal concentration was determined for in vitro macrophage intervention.

Differentially expressed genes (DEGs) in HBV-induced and acetaminophen-induced ALF were identified from GEO datasets. The correlation between target gene expression and immune cell infiltration in ALF liver tissue was analyzed. AST, ALT, TNF-α, HMGB1, IL-1β, IL-6, and IL-10 levels were measured, and liver histopathology was assessed. Macrophage polarization was analyzed via immunofluorescence, flow cytometry, and Western blot. Glycolysis-related enzymes and metabolites, including HK2, PFK-1, PKM2, and LDHA, were quantified. Cellular ultrastructure was examined by transmission electron microscopy.

Five key glycolysis-regulating genes (HK2, CDK1, SOD1, VEGFA, GOT1) were identified, with significant involvement in the HIF-1 signaling pathway. Immune infiltration was markedly higher in ALF liver tissue. SNRS improved survival, reduced ALT/AST levels, alleviated liver injury, and modulated macrophage polarization by decreasing CD86 and increasing CD163 expression. In vitro, SNRS inhibited LPS-induced inflammatory cytokine release, lactate production, p-mTOR/mTOR ratio, and HIF-1α expression.

SNRS modulates macrophage polarization and glucose metabolism reprogramming via the mTOR/HIF-1α pathway, showing promise as a treatment for ALF.

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.

Hepatitis is a chronic inflammatory liver disease and an important cause of liver fibrosis, which can progress to cirrhosis and even hepatocellular carcinoma if left untreated. However, liver fibrosis is a reversible disease, so finding new intervention targets and molecular markers is the key to preventing and treating liver fibrosis. Ginseng, the roots of Panax ginseng C. A. Meyer, is a precious Traditional Chinese Medicines with high medicinal value and is known as the "king of all herbs", and its active ingredient, ginsenoside Rg3 is a rare saponin and a new class of drug, one of the most thoroughly and extensively studied in a large number of studies. Ginsenoside Rg3 is an active ingredient extracted from ginseng that possesses a variety of biological activities, including anti-inflammatory, antioxidant, and anti-fibrotic effects. Several studies have suggested that ginsenoside Rg3 may help reduce hepatic inflammation and oxidative stress, thereby slowing the progression of liver fibrosis. Ginsenoside Rg3 may have some therapeutic effects on liver fibrosis, and the underlying molecular mechanisms behind these effects are attributed to cellular autophagy, apoptosis, and anti-inflammation, as well as the modulation of antioxidant activity and multiple signaling pathways. The molecular mechanisms behind the inhibitory effect of ginsenoside Rg3 on hepatic fibrosis are reviewed, with a view to providing reference for related studies.

Intravascular hemolysis releases hemoglobin (Hb) from red blood cells under specific conditions, yet the effect of hemolysis in aquaculture systems remain poorly understood. In this study, a continuous hemolysis model for grass carp was established by injection of phenylhydrazine (PHZ) to investigate the mechanistic impacts of sustained hemolysis. PHZ-induced hemolysis altered liver color, and subsequent hematoxylin and eosin staining revealed substantial Hb accumulation in the head kidney, accompanied by inflammatory cell infiltration and vacuolization in liver tissue. Quantitative real-time PCR and western blotting confirmed that PHZ treatment significantly upregulated Real-time fluorescence quantitative PCR and Western blot confirmed that PHZ treatment significantly up-regulated the expression of iron metabolism-related genes and proteins, including transferrin (Tf), ferritin, ferroportin 1 (FPN1), transferrin receptor 1 (TfR1), nuclear receptor coactivator 4 (NCOA4), divalent metal transporter 1 (DMT1), and six-transmembrane epithelial antigen of prostate 3 (STEAP3). Further investigation of PHZ-induced hemolysis effects on tissues showed that inflammation- and antioxidant enzyme-related genes in the liver and head kidney were significantly upregulated, indicating that hemolysis activated the antioxidant system and intensified inflammatory responses. Perls' staining revealed iron deposition in the head kidney and liver at ten and fourteen days post-PHZ injection. Moreover, β-galactosidase staining and transmission electron microscopy showed increased cellular senescence and mitochondrial damage, respectively, as a result of PHZ-induced hemolysis. In vitro assays with hemin treatment demonstrated increased Fe2+ content in CIK and L8824 cells, which induced oxidative stress, upregulated iron metabolism and inflammatory genes, and ultimately led to cell death. These findings suggest that excessive Hb release during sustained hemolysis leads to iron overload, elevates reactive oxygen species production, disrupts antioxidant balance, and ultimately causes cellular damage.

Macrophages play crucial roles in immune response and tissue homeostasis, with their functions becoming increasingly complex in obesity-mediated metabolic disorders. This review explores the extensive range of macrophage activities within adipose and liver tissues, emphasizing their contribution to the pathogenesis and progression of obesity and its related metabolic dysfunction-associated steatotic liver disease (MASLD). In the context of obesity, macrophages respond adaptively to lipid overloads and inflammatory cues in adipose tissue, profoundly influencing insulin resistance and metabolic homeostasis. Concurrently, their role in the liver extends to moderating inflammation and orchestrating fibrotic responses, integral to the development of MASLD. Highlighting the spectrum of macrophage phenotypes across these metabolic landscapes, we summarize their diverse roles in linking inflammatory processes with metabolic functions. This review advocates for a deeper understanding of macrophage subsets in metabolic tissues, proposing targeted research to harness their therapeutic potential in mitigating MASLD and other metabolic disorders.

As a central hub for metabolism, the liver exhibits strong adaptability to maintain homeostasis in response to food fluctuations throughout evolution. However, the mechanisms governing this resilience remain incompletely understood. In this study, we identified Receptor interacting protein kinase 1 (RIPK1) in hepatocytes as a critical regulator in preserving hepatic homeostasis during metabolic challenges, such as short-term fasting or high-fat dieting. Our results demonstrated that hepatocyte-specific deficiency of RIPK1 sensitized the liver to short-term fasting-induced liver injury and hepatocyte apoptosis in both male and female mice. Despite being a common physiological stressor that typically does not induce liver inflammation, short-term fasting triggered hepatic inflammation and compensatory proliferation in hepatocyte-specific RIPK1-deficient (Ripk1-hepKO) mice. Transcriptomic analysis revealed that short-term fasting oriented the hepatic microenvironment into an inflammatory state in Ripk1-hepKO mice, with up-regulated expression of inflammation and immune cell recruitment-associated genes. Single-cell RNA sequencing further confirmed the altered cellular composition in the liver of Ripk1-hepKO mice during fasting, highlighting the increased recruitment of macrophages to the liver. Mechanically, our results indicated that ER stress was involved in fasting-induced liver injury in Ripk1-hepKO mice. Overall, our findings revealed the role of RIPK1 in maintaining liver homeostasis during metabolic fluctuations and shed light on the intricate interplay between cell death, inflammation, and metabolism.

Perfluorooctanoic acid (PFOA) is a persistent pollutant that has gained worldwide attention, owing to its widespread presence in the environment. Previous studies have reported that PFOA upregulates lipid metabolism and is associated with liver injury in humans. However, when the fatty acid degradation pathway is activated, lipid accumulation still occurs, suggesting the presence of unknown pathways and mechanisms that remain to be elucidated. In this study, adult C57BL/6N mice were exposed to PFOA at 0.1, 1, and 10 mg/kg/day. Using integrated metabolomics and transcriptomics, it was uncovered that arginine metabolism was differentially downregulated in all three groups. In vitro studies confirmed the downregulation of arginine metabolism in MIHA cell lines treated with PFOA. Supplementation of arginine could effectively rescue liver injury and downregulate the chemokine levels caused by PFOA. This finding highlights the contribution of arginine metabolism in maintaining liver health following PFOA exposure and suggests potential mechanisms of metabolic and immune modulation.