N6-methyladenosine (m6A), and its reader protein YTHDF1, play a pivotal role in human tumorigenesis by affecting nearly every stage of RNA metabolism. Autophagy activation is one of the ways by which cancer cells survive hypoxia. However, the possible involvement of m6A modification of mRNA in hypoxia-induced autophagy was unexplored in human hepatocellular carcinoma (HCC). In this study, specific variations in YTHDF1 expression were detected in YTHDF1-overexpressing, -knockout, and -knockdown HCC cells, HCC organoids, and HCC patient-derived xenograft (PDX) murine models. YTHDF1 expression and hypoxia-induced autophagy were significantly correlated in vitro; significant overexpression of YTHDF1 in HCC tissues was associated with poor prognosis. Multivariate cox regression analysis identified YTHDF1 expression as an independent prognostic factor in patients with HCC. Multiple HCC models confirmed that YTHDF1 deficiency inhibited HCC autophagy, growth, and metastasis. Luciferase reporter assays and chromatin immunoprecipitation demonstrated that HIF-1α regulated YTHDF1 transcription by directly binding to its promoter region under hypoxia. The results of methylated RNA immunoprecipitation sequencing, proteomics, and polysome profiling indicated that YTHDF1 contributed to the translation of autophagy-related genes ATG2A and ATG14 by binding to m6A-modified ATG2A and ATG14 mRNA, thus facilitating autophagy and autophagy-related malignancy of HCC. Taken together, HIF-1α-induced YTHDF1 expression was associated with hypoxia-induced autophagy and autophagy-related HCC progression via promoting translation of autophagy-related genes ATG2A and ATG14 in a m6A-dependent manner. Our findings suggest that YTHDF1 is a potential prognostic biomarker and therapeutic target for patients with HCC.

Objective This study aimed to assess the efficacy and safety of camrelizumab plus apatinib in patients with resectable hepatocellular carcinoma (HCC) as neoadjuvant therapy. Methods Initially, 20 patients with HCC were screened and 18 patients with resectable HCC were enrolled in this open-label, single-arm, phase II clinical trial. Patients received three cycles of neoadjuvant therapy including three doses of camrelizumab concurrent with apatinib for 21 days followed by surgery. Four to 8 weeks after surgery, patients received eight cycles of adjuvant therapy with camrelizumab in combination with apatinib. Major pathological reactions (MPR), complete pathological reactions (pCR), objective response rate (ORR), relapse-free survival (RFS), and adverse events (AE) were assessed. In addition, cancer tissue and plasma samples were collected before and after treatment, and genetic differences between responding and non-responding lesions were compared by tumor immune microenvironment (TIME) analysis, circulating tumor DNA (ctDNA) analysis and proteomics analysis. Results In 18 patients with HCC who completed neoadjuvant therapy, 3 (16.7%) and 6 (33.3%) patients with HCC reached ORR based on Response Evaluation Criteria in Solid Tumors (RECIST) V.1.1 and modified RECIST criteria, respectively. Of the 17 patients with HCC who received surgical resection, 3 (17.6%) patients with HCC reported MPR and 1 (5.9%) patient with HCC achieved pCR. The 1-year RFS rate of the enrolled patients was 53.85% (95% CI: 24.77% to 75.99%). Grade 3/4 AEs were reported in 3 (16.7%) of the 18 patients, with the most common AEs being rash (11.1%), hypertension (5.6%), drug-induced liver damage (5.6%), and neutropenia (5.6%) in the preoperative phase. The 289 NanoString panel RNA sequencing showed that TIME cell infiltration especially dendritic cells (DCs) infiltration was better in responding tumors than in non-responding tumors. Our results of ctDNA revealed a higher positive rate (100%) among patients with HCC with stage IIb–IIIa disease. When comparing patients with pCR/MPR and non-MPR, we observed more mutations in patients who achieved pCR/MPR at baseline (6 mutations vs 2.5 mutations, p=0.025). Patients who were ctDNA positive after adjuvant therapy presented a trend of shorter RFS than those who were ctDNA negative. Proteomic analysis suggested that abnormal glucose metabolism in patients with multifocal HCC might be related to different sensitivity of treatment in different lesions. Conclusion Perioperative camrelizumab plus apatinib displays a promising efficacy and manageable toxicity in patients with resectable HCC. DCs infiltration might be a predictive marker of response to camrelizumab and apatinib as well as patients’ recurrence. ctDNA as a compose biomarker can predict pathological response and relapse. Abnormal glucose metabolism in patients with multifocal HCC may be related to different sensitivity of treatment in different lesions. Trial registration number NCT04297202.

Hepatic ischemia-reperfusion injury is a significant complication of partial hepatic resection and liver transplantation, impacting the prognosis of patients undergoing liver surgery. The protein proprotein convertase subtilisin/kexin type 9 (PCSK9) is primarily synthesized by hepatocytes and has been implicated in myocardial ischemic diseases. However, the role of PCSK9 in hepatic ischemia-reperfusion injury remains unclear. This study aims to investigate the role and mechanism of PCSK9 in hepatic ischemia-reperfusion injury. We first examined the expression of PCSK9 in mouse warm ischemia-reperfusion models and AML12 cells subjected to hypoxia/reoxygenation. Subsequently, we explored the impact of PCSK9 on liver ischemia-reperfusion injury by assessing mitochondrial damage and the resulting inflammatory response. Our findings reveal that PCSK9 is up-regulated in response to ischemia-reperfusion injury and exacerbates hepatic ischemia-reperfusion injury. Blocking PCSK9 can alleviate hepatocyte mitochondrial damage and the consequent inflammatory response mediated by ischemia-reperfusion. Mechanistically, this protective effect is dependent on mitophagy. Inhibiting PCSK9 in hepatocytes attenuates the inflammatory responses triggered by reactive oxygen species and mitochondrial DNA by promoting PINK1-Parkin-mediated mitophagy. This, in turn, ameliorates hepatic ischemia-reperfusion injury.

The prevalence of Metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing year by year and has become one of the leading causes of end-stage liver disease worldwide. Triggering Receptor Expressed on Myeloid Cells 2 (Trem2) has been confirmed to play an essential role in the progression of MASLD, but its specific mechanism still needs to be clarified. This study aims to explore the role and mechanism of Trem2 in MASLD. Human liver tissues were obtained from patients with MASLD and controls. Myeloid-specific knockout mice (Trem2^mKO) and myeloid-specific overexpression mice (Trem2^TdT) were fed a high-fat diet, either AMLN or CDAHFD, to establish the MASLD model. Relevant signaling molecules were assessed through lipidomics and RNA-seq analyses after that. Trem2 is upregulated in human MASLD/MASH-associated macrophages and is associated with hepatic steatosis and inflammation progression. Hepatic steatosis and inflammatory responses are exacerbated with the knockout of myeloid Trem2 in MASLD mice, while mice overexpressing Trem2 exhibit the opposite phenomenon. Mechanistically, Trem2^mKO can aggravate macrophage pyroptosis through the PI3K/AKT signaling pathway and amplify the resulting inflammatory response. At the same time, Trem2 promotes the inflammation resolution phenotype transformation of macrophages through TGFβ1, thereby promoting tissue repair. Myeloid Trem2 ameliorates the progression of Metabolic dysfunction-associated steatotic liver disease by regulating macrophage pyroptosis and inflammation resolution. We believe targeting myeloid Trem2 could represent a potential avenue for treating MASLD.