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Autophagy classically functions to protect cells and organisms during stressful conditions by catabolizing intracellular components to maintain energy homeostasis. Lysosome-autophagosome fusion is a critical step in emptying degraded unwanted contents. However, the mechanism of autophagosome fusion with lysosomes is still not fully understood. Here, we report that DNA Damage-Regulated Autophagy Modulator 1 (DRAM1) interacts with Vesicle Associated Membrane Protein 8 (VAMP8) to mediate the fusion of autophagosomes with lysosomes. This DRAM1-VAMP8 interaction is enhanced upon stimulation of autophagy. However, DRAM1 preferentially mediates the fusion between autophagosomes and lysosomes by enhancing the assembly of the STX17-SNAP29-VAMP8 complex. Moreover, we reveal that DRAM1 specifically promotes the stability of lysosomal VAMP8 via inhibiting VAMP8 degradation by CHIP mediating ubiquitination. We also identify that DRAM1 inhibits the ubiquitination of VAMP8 at Lys 68,72, and 75 via competitively binding with CHIP. Furthermore, we demonstrate that DRAM1 promotes the extravasation of Hepatocellular Carcinoma (HCC) cells, and this process relies on enhanced autophagosome degradation. Our study reveals a mechanism for regulating autolysosome formation by DRAM1-VAMP8 association and suggests a potential strategy to inhibit the extravasation of HCC. DNA Damage Regulated Autophagy Modulator 1 (DRAM1) plays pivotal roles in autophagy regulation. Here, the authors show that DRAM1 stabilizes lysosomal VAMP8, thereby promoting autolysosome maturation. Furthermore, they establish that DRAM1–VAMP8 axis enhances autophagic flux and facilitates hepatocellular carcinoma extravasation, as validated in both zebrafish xenograft and mouse metastatic models.

Background Acute liver failure (ALF) is a complicated condition that is characterized by global hepatocyte death and often requires immediate liver transplantation. However, this therapy is limited by shortage of donor organs. Mesenchymal stem cells (MSCs) and hepatocytes are two attractive sources of cell-based therapies to treat ALF. The combined transplantation of hepatocytes and MSCs is considered to be more effective for the treatment of ALF than single-cell transplantation. We have previously demonstrated that HNF4α-overexpressing human umbilical cord MSCs (HNF4α-UMSCs) promoted the expression of hepatic-specific genes. In addition, microencapsulation allows exchange of nutrients, forming a protective barrier to the transplanted cells . Moreover, encapsulation of hepatocytes improves the viability and synthetic ability of hepatocytes and circumvents immune rejection. This study aimed to investigate the therapeutic effect of microencapsulation of hepatocytes and HNF4α-UMSCs in ALF mice. Methods Human hepatocytes and UMSCs were obtained separately from liver and umbilical cord, followed by co-encapsulation and transplantation into mice by intraperitoneal injection. LPS/D-gal was used to induce ALF by intraperitoneal injection 24 h after transplantation. In addition, Raw 264.7 cells (a macrophage cell line) were used to elucidate the effect of HNF4α-UMSCs-hepatocyte microcapsules on polarization of macrophages. The protein chip was used to define the important paracrine factors in the conditioned mediums (CMs) of UMSCs and HNF4α-UMSCs and investigate the possible mechanism of HNF4α-UMSCs for the treatment of ALF in mice. Results HNF4α-UMSCs can enhance the function of primary hepatocytes in alginate–poly-L-lysine–alginate (APA) microcapsules. The co-encapsulation of both HNF4α-UMSCs and hepatocytes achieved better therapeutic effects in ALF mice by promoting M2 macrophage polarization and reducing inflammatory response mainly mediated by the paracrine factor HB-EGF secreted by HNF4α-UMSCs. Conclusions The present study confirms that the co-encapsulation of HNF4α-UMSC and hepatocytes could exert therapeutic effect on ALF mainly by HB-EGF secreted by HNF4α-UMSCs and provides a novel strategy for the treatment of ALF.

Alternative polyadenylation (APA) is critical for shaping transcriptome diversity by generating mRNA isoforms that differ in the length of their 3′untranslated region (3′UTR). APA dysregulation, a defined feature of tumorigenesis, remains poorly understood in colorectal cancer (CRC). Here, CRISPR/Cas9 screening identifies APA regulator NUDT21 as a key driver of CRC progression. NUDT21 is overexpressed in CRC tumors and correlates with poor prognosis in CRC patients. Genetic ablation of NUDT21 impairs CRC cell proliferation and triggers CD8+ T cell anti‐tumor response through disrupting cholesterol biosynthesis, leading to delayed tumor progression in syngeneic mouse models. Mechanistically, NUDT21 promotes the generation of cyclin‐dependent kinase 19 (CDK19) mRNA isoforms with long 3′UTR by directing usage of distal polyadenylation sites. The long 3′UTR facilitates the export of CDK19 transcripts to the cytoplasm and supports their efficient translation, with no impact on their stability. Truncation of the long 3′UTR of Cdk19 recapitulates cholesterol biosynthesis and proliferative impairments, as well as the enhanced anti‐tumor CD8+ T cell activity observed upon NUDT21 depletion, whereas CDK19 overexpression rescues these phenotypes. The findings establish the NUDT21‐CDK19 axis as a central hub integrating APA manner, cholesterol metabolic reprogramming, and immune evasion in CRC, unveiling potential therapeutic opportunities. NUDT21 is overexpressed in colorectal cancer tumors and promotes colorectal cancer progression. NUDT21 promotes the production of a cyclin‐dependent kinase 19 (CDK19) mRNA isoform with a long 3′ UTR, which enhances cytoplasmic export and translation. Truncation of the CDK19 long 3′ UTR phenocopies NUDT21 loss, recapitulating the defects in cholesterol biosynthesis and the activation of anti‐tumor CD8⁺ T cell immunity.

Autophagy is a highly conserved cellular process that plays a crucial role in maintaining cellular homeostasis by degrading damaged organelles, misfolded proteins, and other cellular components. p62/SQSTM1 functions as a selective autophagy receptor by binding polyubiquitinated cargo through its UBA domain and linking it to microtubule-associated protein light chain 3 (LC3)-decorated autophagosomes. Moreover, p62 acts as a signaling hub and is essential in response to various stressors, including nutrient deprivation and oxidative stress. Post-translational modifications (PTMs) critically regulate p62’s multifaceted roles, controlling p62’s phase separation, cargo recruitment, signaling interactions, and autophagic degradation efficiency. The dysregulation of p62 PTMs is closely related to the occurrence and development of human diseases, particularly neurodegenerative disorders and certain cancers. This review summarizes the main PTM events of p62 discovered to date that influence the autophagy process, including phosphorylation, acetylation, ubiquitination, and S-acylation, as well as their known contributions to protein aggregation and disease. The PTMs of p62 dynamically regulate autophagy, protein aggregation, and cellular signaling, underscoring its importance as a potential therapeutic target and biomarker for these diseases.

Background Increases in the levels of serum C-reactive protein (CRP) and creatinine (Cr) and decreases in those of albumin (Alb) are commonly observed in acute pancreatitis (AP). We aimed to evaluate the efficacy of the Cr/Alb and CRP/Alb ratios in the prediction of surgical treatment effect in AP patients. Methods This study retrospectively analyzed clinical data obtained from 140 AP patients who underwent debridement from January 2008 to November 2018 in Shanghai Ruijin Hospital. The Cr/Alb and CRP/Alb ratios at admission and before surgery were assessed in the analysis of clinical statistics, prediction of prognoses, and logistic regression analysis. Results The admission Cr/Alb had the best predictive value of the four ratios. This value was significantly higher in patients with re-operation and those who died ( P  < 0.05) and was correlated with the Acute Physiology and Chronic Health Evaluation (APACHE II) score, admission CRP/Alb, preoperative Cr/Alb, and post-operative complications. The admission Cr/Alb could predict the risk of AP-related re-operation and mortality with sensitivities, specificities and areas under the curve of 86.3%, 61.7% and 0.824, and 73.4%, 81.3% and 0.794, respectively. At a cut-off value of 3.43, admission Cr/Alb values were indicative of a worse clinical state, including impaired laboratory test values, APACHE II scores, rates of post-operative complications and re-operation, and mortality ( P  < 0.05). In the logistic regression analysis, admission Cr/Alb values were independently related to the APACHE II score, post-operative renal failure, and mortality. Conclusion Cr/Alb is a novel but promising, easy-to-measure, reproducible, non-invasive prognostic score for the prediction of the effect of debridement in AP patients.

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is an E3 ubiquitin ligase that plays a crucial role in inflammation, immune responses, and tumor development. It was reported that TRAF6 primarily catalyzes K63-linked polyubiquitination to stabilize substrate proteins, thereby facilitating the malignant phenotype of tumors. Beyond its cytoplasmic roles, TRAF6 undergoes nuclear translocation in response to specific stimuli, where it interacts with chromatin modifiers. TRAF6 acts as a central mediator in key signaling pathways downstream of the Toll-like receptor, interleukin-1 receptor, and tumor necrosis factor receptor superfamilies, including NF-κB activation. TRAF6 exerts diverse oncogenic functions, including promoting cell proliferation, migration, metastasis, immune evasion, and therapy resistance. This involves modulating cellular pathways such as NF-κB and MAPK signaling, which contribute to malignant progression. Aberrant TRAF6 activation contributes to the pathogenesis of multiple malignancies, including colorectal cancer, melanoma, hepatocellular carcinoma, and acute myeloid leukemia, making it a promising therapeutic target for cancer treatment. This review summarizes the structural features, substrate diversity, and multifaceted roles of TRAF6 in cancer, as well as the development of TRAF6-targeting drugs and strategies. We hope this review can provide a comprehensive perspective on TRAF6-targeted therapeutic strategies for cancer.

HDAC3 is highly expressed in colorectal cancer (CRC) and associated with poor prognosis. This study reveals that HDAC3 deletion dually regulates chemokine expression through epigenetic mechanisms, promoting CD8⁺ T cell infiltration (via CXCL10) on one hand, while enhancing the recruitment of myeloid-derived suppressor cells (MDSCs) (via CXCL1/2/3/5) on the other. The latter, mediated through CXCR2 signaling, counteracts the intrinsic anti-tumor effect of HDAC3 deletion. We further demonstrate that combining a CXCR2 inhibitor effectively blocks MDSC infiltration and significantly enhances the immunotherapeutic efficacy mediated by HDAC3 deletion. This study systematically elucidates the “double-edged sword” role of HDAC3 in the CRC immune microenvironment and provides a theoretical and experimental basis for an HDAC3/CXCR2 dual-targeting therapeutic strategy.

Aims Purinergic signaling-mediated mitochondria dysfunction and innate immune-mediated inflammation act as triggers during acetaminophen (APAP)-induced liver injury (AILI). However, the underlying mechanisms by which purinoceptor regulates mitochondria function and inflammation response in the progression of AILI remains unclear. Methods First, the hepatic level of purinergic receptor P2X 1 (P2RX1) was identified in the DILI patients and APAP-induced WT mice. P2rx1 knockout (KO) mice ( P2rx1 −/− ) with 300 mg/kg APAP challenge were used for the analysis of the potential role of P2RX1 in the progression of AILI. Administration of DMX, the activator of stimulator of interferon genes (STING), was performed to investigate the effects of the STING-related pathway on APAP-treated P2rx1 −/− mice. Results The elevated hepatic P2RX1 levels were found in DILI patients and the AILI mice. P2rx1 depletion offered protection against the initial stages of AILI, mainly by inhibiting cell death and promoting inflammation resolution, which was associated with alleviating mitochondria dysfunction. Mechanistically, P2rx1 depletion could inhibit STING-TANK-binding kinase 1 (TBK1)-P65 signaling pathways in vivo. We then showed that DMX-mediated STING activation could greatly aggravate the liver injury of P2rx1 −/− mice treated with APAP. Conclusion Our data confirmed that P2RX1 was inducted during AILI, identified P2RX1 as a novel regulator in mitochondria dysfunction and STING pathways, and suggested a promising therapeutic approach for AILI involving the blockade of P2RX1. Graphical abstract 1. It first demonstrated the protective effects of P2rx1 deficiency on acetaminophen-induced liver injury (AILI). 2. P2rx1 knockout alleviates mitochondria function and promotes inflammation resolution after APAP treatment. 3. It first reported the regulation of P2RX1 on the STING signaling pathway in the progress of AILI. 4. P2RX1 blockade is a promising therapeutic strategy for AILI.

Background Impaired liver regeneration in hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) patients is closely related to prognosis; however, the mechanisms are not yet defined. Liver-derived extracellular vesicles (EVs) may be involved in the dysregulation of liver regeneration. Clarifying the underlying mechanisms will improve the treatments for HBV-ACLF. Methods EVs were isolated by ultracentrifugation from liver tissues of HBV-ACLF patients (ACLF_EVs) after liver transplantation, and their function was investigated in acute liver injury (ALI) mice and AML12 cells. Differentially expressed miRNAs (DE-miRNAs) were screened by deep miRNA sequencing. The lipid nanoparticle (LNP) system was applied as a carrier for the targeted delivery of miRNA inhibitors to improve its effect on liver regeneration. Results ACLF_EVs inhibited hepatocyte proliferation and liver regeneration, with a critical role of miR-218-5p. Mechanistically, ACLF_EVs fused directly with target hepatocytes and transferred miR-218-5p into hepatocytes, acting by suppressing FGFR2 mRNA and inhibiting the activation of ERK1/2 signaling pathway. Reducing the level of miR-218-5p expression in the liver of ACLF mice partially restored liver regeneration ability. Conclusion The current data reveal the mechanism underlying impaired liver regeneration in HBV-ACLF that promotes the discovery of new therapeutic approaches. Graphical abstract