Liver ischemia/reperfusion injury (IRI) is an inevitable pathological process exacerbating the occurrence of rejection in liver transplantation. At present, there is still a lack of sufficient cognition for the mechanism as well as effective clinical strategies. F-box/WD repeat-containing protein 5 (FBXW5), a key modulator of stress signalling, was recently reported to participate in hepatic immunity. However, the role of FBXW5 in liver IRI is still unclear. In the present study, we found expression of FBXW5 was increased in liver IRI both in vivo and in vitro. Inhibition of FBXW5 significantly alleviated both mitogen-activated protein kinase (MAPK) and inhibitor of nuclear factor kappa-B kinase (IKK) pathways, thus resulting in cytokine release, hepatic pathological injury and apoptosis. Over-expression of FBXW5 achieved an opposite effect. Investigations on the mechanism showed that FBXW5 intensified hepatic inflammation by promoting phosphorylation of ASK1, while blockade of TRAF6 could abolish this process. Moreover, reinforce of mTOR amplified the anti-inflammatory efficacy derived from inhibition of FBXW5, indicating the function of FBXW5/ASK1/TRAF6 axis in hepatic IRI might be relatively independent of mTOR-guided M2 polarization of Kupffer cell. Taken together, FBXW5 could be a key accelerator in liver IRI by enhancing activation of ASK1 in a TRAF6-dependent manner. The joint intervention towards both FBXW5 and mTOR might be a promising strategy to protect liver from IRI.

Hypoxia, immune evasion, and metabolic reprogramming are key features of hepatocellular carcinoma (HCC) that limit the efficacy of therapies. Members of the solute carrier (SLC) family regulate metabolite homeostasis within tumor cells to maintain tumor survival under stressed conditions like hypoxia. Investigating SLC family members could offer insights into the hypoxic microenvironment of HCC and potentially help identify improved therapeutic strategies. In this study, we identified SLC27A2 as a hypoxia-responsive gene frequently downregulated in HCC, correlating with increased aggressiveness and adverse outcomes. HCC cells with low SLC27A2 expression exhibited enhanced hypoxia tolerance and resistance to hypoxia-related therapies, such as transarterial chemoembolization and antiangiogenic agents. Mechanistically, SLC27A2 downregulation led to reduced long-chain fatty acid (LCFA) intake, preventing LCFA accumulation under hypoxic conditions and mitigating cytotoxicity caused by lipid peroxidation. SLC27A2-deficient HCC cells were sensitive to glutaminase and fatty acid synthase inhibitors. The LCFAs in SLC27A2-deficient HCC were taken up by tumor-associated macrophages (TAM), activating PPARγ transcriptional activity and promoting the enrichment of SPP1+ TAMs. Although this process led to immunosuppression, it presented an opportunity for applying anti–PD-1 therapy. In conclusion, the redistribution of LCFAs between HCC cells and TAMs, mediated by low SLC27A2 expression in cancer cells, supports adaptation to stress, promoting tumor progression and immunosuppression. The redistribution of LCFAs introduces molecular vulnerabilities and specific therapeutic opportunities for HCC. Significance: SLC27A2 downregulation in response to environmental stressors limits fatty acid uptake to mitigate lipid peroxidation in hepatocellular carcinoma, providing potential opportunities for precision treatment and calling for caution with fatty acid–targeted therapies.

Background: Although hepatic ischemia–reperfusion injury (IRI) frequently occurs during liver resection and transplantation, the underlying mechanisms remain incompletely understood. Through high-throughput sequencing, we found that v-maf musculoaponeurotic fibrosarcoma oncogene homolog F (MAFF) expression was significantly increased after hepatic IRI. The specific role of MAFF, a basic leucine zipper (bZIP) transcription factor, in hepatic IRI is unknown. In the present study, we aimed to explore the effect of MAFF on hepatic IRI injury. Approach and results: Adenovirus vectors carrying the MAFF gene were administered to mice to explore the potential significance of MAFF. After ischemia–reperfusion, MAFF expression was significantly upregulated, suggesting a potential association between MAFF expression and hepatocyte apoptosis. A reduction in MAFF expression was demonstrated to worsen hepatic impairment and enhance the expression of proinflammatory cytokines in mice following ischemia–reperfusion. Conversely, MAFF overexpression had the opposite effect. Mechanistically, the combination of CUT&Tag and RNA sequencing technologies identified cardiotrophic factor-like cytokine 1 (CLCF1) as a direct transcriptional target for MAFF and BTB and CNC homology 1 (BACH1) heterodimers. This interaction subsequently triggers signal transducer and activator of transcription 3 (STAT3) signaling. Conclusions: MAFF alleviates hepatic ischemia–reperfusion injury by reducing hepatocyte apoptosis and the inflammatory response through the activation of the CLCF1/STAT3 signaling pathway, offering valuable insights into the impact of MAFF on liver protection and potential therapeutic targets for liver treatment. Graphical

Background and Aims: The aims of the present study were to characterize the PANoptosis signature in intrahepatic cholangiocarcinoma (ICC) patients, construct a novel model to guide clinical diagnosis and treatment, and further explore the associated molecular mechanisms of drug resistance. Approach and Results: In total, 85 PANoptosis-related genes that possess both PANoptosis and multi-omics features were, respectively, screened from transcriptomic data from the OEP001105 public cohort and from transcriptomic and proteomic sequencing data from The First Affiliated Hospital of Chongqing Medical University. A novel framework integrating Cox regression analysis and 5 machine learning algorithms was developed to identify the 5 hub genes (POSTN, SFN, MYOF, HOGA1, and PECR). The subsequently constructed PANoptosis risk score demonstrates outstanding performance in predicting prognosis and clinical translation across multicenter cohorts with multi-omics profiling. Bulk and single-cell transcriptome profiling were used to investigate the tumor microenvironment, emphasizing the crucial role of macrophages in the tumor microenvironment of ICCs. Moreover, a positive spatial correlation of cancer-associated fibroblasts–derived POSTN expression with tumor-associated macrophages infiltration and PD-L1/PD-L2 expression in ICC patients was observed, suggesting that overexpression of POSTN may lead to resistance to immune checkpoint blockade therapy in ICC patients. Conclusions: The present study identified a precise prognostic and treatment strategy for ICC patients prone to PANoptosis, investigated the molecular mechanisms of PANoptosis in ICC cells, and highlighted the potential clinical relevance of the PANoptosis risk score in predicting prognosis and therapy response. These findings will help guide clinical treatment strategies for ICC.

Acute rejection (AR) is a significant complication in liver transplantation, impacting graft function and patient survival. Kupffer cells (KCs), liver-specific macrophages, can polarize into pro-inflammatory M1 or anti-inflammatory M2 phenotypes, both of which critically influence AR outcomes. Angiopoietin-like 4 (ANGPTL4), a secretory protein, is recognized for its function in regulating inflammation and macrophage polarization. This study investigates the effects of ANGPTL4 on KC polarization through cellular interactions between hepatocytes (HCs) and KCs. Using a rat orthotopic liver transplantation model, we observed reduced ANGPTL4 expression during AR, whereas increased ANGPTL4 levels were linked to immune tolerance. Administration of ANGPTL4 recombinant protein improved liver function, suppressed inflammation, and promoted M2 polarization of KCs. Co-culture experiments demonstrated that hepatocyte-derived ANGPTL4 significantly modulates KC polarization and inflammatory responses, mainly by inhibiting the NF-κB signaling pathway. The results emphasize the promise of ANGPTL4 as a therapeutic target to reduce AR and improve liver transplant outcomes by influencing hepatocyte-KC interactions.

Cleavage stimulation factor subunit 2 (CSTF2) is a fundamental factor in the regulation of 3′-end cleavage and alternative polyadenylation of pre-mRNAs. Previous work has identified a tumor-promoting role of CSTF2, suggesting that it may represent a potential therapeutic target. In this study, we aimed to elucidate the mechanistic function of CSTF2 in hepatocellular carcinoma (HCC). CSTF2 upregulation was frequent in HCC, and elevated levels of CSTF2 correlated with poor patient prognosis. Although CSTF2 inhibition did not suppress HCC growth under nonstress conditions, it supported tolerance and survival of HCC cells under hypoxic conditions. Mechanistically, CSTF2 increased phosphoglycerate kinase 1 (PGK1) protein production to enhance glycolysis, thereby sustaining the energy supply under hypoxic conditions. CSTF2 shortened the 3′ untranslated region of PGK1 pre-mRNA by binding near the proximal polyadenylation site. This shortening led to a loss of N6-methyladenosine (m6A) modification sites that are bound by YTH m6A RNA-binding protein F2 and increase degradation of PGK1 mRNA. Concurrently, hypoxia increased m6A modification of PGK1 mRNA near the proximal polyadenylation site that was recognized by the YTH m6A RNA-binding protein C1, which recruited CSTF2 to enhance the shortening of the PGK1 3′ untranslated region. A small-molecule screen identified masitinib as an inhibitor of CSTF2. Masitinib counteracted PGK1 upregulation by CSTF2 and suppressed the growth of HCC xenograft and patient-derived organoid models. In conclusion, this study revealed a function of CSTF2 in supporting HCC survival under hypoxia conditions through m6A modification evasion and metabolic reprogramming, indicating that inhibiting CSTF2 may overcome hypoxia tolerance in HCC. Significance: Targeting CSTF2 inhibits hepatocellular carcinoma survival in hypoxic microenvironments, which may be a promising therapeutic strategy for treating liver cancer.