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Intervertebral disc degeneration (IVDD) is a chronic degenerative disease with a complex pathophysiological mechanism. Increasing evidence suggests that the NOD-like receptor thermal protein domain associated protein 3 (NLRP3)-mediated pyroptosis of nucleus pulposus cells (NPCs) plays a crucial role in the pathological progression of IVDD. Pyroptosis is a novel form of programmed cell death characterized by the formation of plasma membrane pores by gasdermin family proteins, leading to cell swelling, membrane rupture, and the release of inflammatory cytokines, which trigger an inflammatory response. The close relationship between pyroptosis and mitophagy has been previously described in various diseases, but the crosstalk between pyroptosis and mitophagy in IVDD remains unexplored. Cellular repressor of E1A-stimulated genes 1 (CREG1) is a secreted glycoprotein involved in cell differentiation and homeostasis regulation and has been shown to promote lysosomal biogenesis and function. However, the potential role and underlying mechanisms of CREG1 in the progression of IVDD have not yet been reported. In this study, we first observed that CREG1 is downregulated following IVDD and that pyroptosis occurs. Furthermore, CREG1 knockdown inhibited NPC proliferation and exacerbated apoptosis and degeneration. Moreover, we confirmed that CREG1 knockdown induced NLRP3 activation while also leading to mitophagy inhibition and mitochondrial dysfunction in NPCs. CREG1 overexpression ameliorated LPS-induced mitophagy inhibition and mitochondrial dysfunction by promoting PINK1/Parkin-mediated mitophagy, thereby suppressing NLRP3 inflammasome activation. However, these protective effects were reversed by pretreatment with the mitophagy inhibitor cyclosporin A (CsA). In a rat model of IVDD, imaging and histological assessments revealed that CREG1 overexpression effectively alleviated the progression of IVDD. Additionally, CREG1 overexpression reduced the expression of NLRP3, caspase-1, and IL-1β while increasing the expression of collagen II, PINK1 and LC3, delaying the course of IVDD. Overall, this study highlights the importance of the interplay between CREG1-mediated regulation of mitophagy and pyroptosis in the pathogenesis of IVDD, identifying CREG1 as a promising therapeutic target for IVDD treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

Ischemic stroke is the primary cause of mortality for individuals with disability worldwide. Tripartite motif 37 (TRIM37) plays multiple regulatory roles in various cellular processes. Our research aimed to investigate the effects of TRIM37 on the progression of ischemic stroke and its related mechanisms. Primary rat brain microvascular endothelial cells (BMECs) were treated with oxygen-glucose deprivation and reoxygenation (OGD/R) and then transduced with pShuttle-H1-TRIM37 shRNA plasmid, pShuttle-CMV-TRIM37 plasmid, or corresponding negative controls. The effects of TRIM37 were also explored in middle cerebral artery occlusion surgery-induced rat brain damage in vivo . Factor VIII staining showed the successful isolation of the primary BMECs. The OGD/R procedure significantly inhibited the cell viability and upregulated the TRIM37 expression in a time-dependent manner. In addition, OGD/R evidently increased the cell permeability, elevated the tumor necrosis factor alpha and intercellular adhesion molecule 1 levels, and upregulated the nuclear expression of nuclear factor (NF)-κB, but downregulated the peroxisome proliferator-activated receptors γ (PPARγ), zonula occludens-1, and cytoplasmic NF-κB expressions, which were reversed by TRIM37 knockdown. Furthermore, TRIM37 interacted with PPARγ and promoted its ubiquitination. The effects on cell permeability and inflammation induced by TRIM37 overexpression were reversed by PPARγ agonist. TRIM37 knockdown also inhibited middle cerebral artery occlusion-induced rat brain damage in vitro . TRIM37 may be a potential therapeutic target for ischemic stroke, and the knockdown of TRIM37 may improve brain injury by regulating the PPARγ/NF-κB pathway to modulate the inflammatory response., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Nephrolithiasis, a common urinary system disorder, exhibits high morbidity and recurrence rates, correlating with renal dysfunction and the increased risk of chronic kidney disease. Nonetheless, the precise role of disrupted cellular metabolism in renal injury induced by calcium oxalate (CaOx) crystal deposition is unclear. The purpose of this study is to investigate the involvement of the ubiquitin-like protein containing PHD and RING finger structural domain 1 (UHRF1) in CaOx-induced renal fibrosis and its impacts on cellular lipid metabolism., Methods: Various approaches, including snRNA-seq, transcriptome RNA-seq, immunohistochemistry, and western blot analyses, were employed to assess UHRF1 expression in kidneys of nephrolithiasis patients, hyperoxaluric mice, and CaOx-induced renal tubular epithelial cells. Subsequently, knockdown of UHRF1 in mice and cells corroborated its effect of UHRF1 on fibrosis, ectopic lipid deposition (ELD) and fatty acid oxidation (FAO). Rescue experiments using AICAR, ND-630 and Compound-C were performed in UHRF1-knockdown cells to explore the involvement of the AMPK pathway. Then we confirmed the bridging molecule and its regulatory pathway in vitro. Experimental results were finally confirmed using AICAR and chemically modified si-UHRF1 in vivo of hyperoxaluria mice model., Results: Mechanistically, UHRF1 was found to hinder the activation of the AMPK/ACC1 pathway during CaOx-induced renal fibrosis, which was mitigated by employing AICAR, an AMPK agonist. As a nuclear protein, UHRF1 facilitates nuclear translocation of AMPK and act as a molecular link targeting the protein phosphatase PP2A to dephosphorylate AMPK and inhibit its activity., Conclusion: This study revealed that UHRF1 promotes CaOx -induced renal fibrosis by enhancing lipid accumulation and suppressing FAO via inhibiting the AMPK pathway. These findings underscore the feasible therapeutic implications of targeting UHRF1 to prevent renal fibrosis due to stones., Competing Interests: Declarations. Ethics approval and consent to participate: The Ethics Committee of the Renmin Hospital of Wuhan University approved the clinical specimen collection (approval number: WDRY2021-KS047). The Experimental Animal Welfare and Ethics Committee of Wuhan University People's Hospital (approval number: WDRM20200604) permitted all animal experiments. Consent for publication: Not applicable. Conflicts of interest: The authors declare no competing interests., (© 2025. The Author(s).)

Translational control shapes the proteome and is particularly important in regulating gene expression under stress. A key source of endothelial stress is treatment with tyrosine kinase inhibitors (TKIs), which lowers cancer mortality but increases cardiovascular mortality. Using a human induced pluripotent stem cell-derived endothelial cell (hiPSC-EC) model of sunitinib-induced vascular dysfunction combined with ribosome profiling, we assessed the role of translational control in hiPSC-ECs in response to stress. We identified staphylococcal nuclease and tudor domain-containing protein 1 (SND1) as a sunitinib-dependent translationally repressed gene. SND1 translational repression was mediated by the mTORC1/4E-BP1 pathway. SND1 inhibition led to endothelial dysfunction, whereas SND1 OE protected against sunitinib-induced endothelial dysfunction. Mechanistically, SND1 transcriptionally regulated UBE2N, an E2-conjugating enzyme that mediates K63-linked ubiquitination. UBE2N along with the E3 ligases RNF8 and RNF168 regulated the DNA damage repair response pathway to mitigate the deleterious effects of sunitinib. In silico analysis of FDA-approved drugs led to the identification of an ACE inhibitor, ramipril, that protected against sunitinib-induced vascular dysfunction in vitro and in vivo, all while preserving the efficacy of cancer therapy. Our study established a central role for translational control of SND1 in sunitinib-induced endothelial dysfunction that could potentially be therapeutically targeted to reduce sunitinib-induced vascular toxicity.

Mitochondrial malfunction associated with impaired mitochondrial quality control and self-renewal machinery, known as mitophagy, is an under-appreciated mechanism precipitating synaptic loss and cognitive impairments in Alzheimer's disease. Promoting mitophagy has been shown to improve cognitive function in Alzheimer's disease animals. However, the regulatory mechanism was unclear, which formed the aim of this study. Here, we found that a neuron-specific loss of Bcl-2 family member BOK in patients with Alzheimer's disease and APPswe/PS1dE9 (APP/PS1) mice is closely associated with mitochondrial damage and mitophagy defects. We further revealed that BOK is the key to the Parkin-mediated mitophagy through competitive binding to the MCL1/Parkin complex, resulting in Parkin release and translocation to damaged mitochondria to initiate mitophagy. Furthermore, overexpressing bok in hippocampal neurons of APP/PS1 mice alleviated mitophagy and mitochondrial malfunction, resulting in improved cognitive function. Conversely, the knockdown of bok worsened the aforementioned Alzheimer's disease-related changes. Our findings uncover a novel mechanism of BOK signalling through regulating Parkin-mediated mitophagy to mitigate amyloid pathology, mitochondrial and synaptic malfunctions, and cognitive decline in Alzheimer's disease, thus representing a promising therapeutic target., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The ferroptosis of osteoblasts has been demonstrated to play a significant role in the development of steroid-induced osteonecrosis of the femoral head (SONFH). Additionally, microRNAs (miRNAs) have been identified as regulators of SONFH progression. However, the precise role of miRNAs in the regulation of osteoblast ferroptosis remains unclear. This study explored the role of exosomal miR-150-3p, derived from bone marrow mesenchymal stem cells (BMSCs), in osteoblast ferroptosis in SONFH. Dexamethasone (DEX) was used to treat osteoblasts to induce ferroptosis. BMSCs exosomes with different levels of miR-150-3p were introduced into a co-culture with the cells. To verify the targeting relationship between growth factor independence 1 (Gfi1) and the miR-150-3p promoter, as well as between miR-150-3p and beta-transducin repeat containing E3 ubiquitin protein ligase (BTRC), respectively, chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP), and dual luciferase assays were employed. It was found that BMSCs-Exos-miR-150-3p mitigated DEX-triggered ferroptosis in osteoblasts. MiR-150-3p directly targeted BTRC, leading to its downregulation in osteoblasts. The BTRC/Nuclear factor erythroid 2-related factor 2 (Nrf2) pathway was involved in the inhibition of DEX-induced osteoblast ferroptosis by BMSCs-Exos-miR-150-3p. Overexpression of BTRC reversed the inhibitory effect of BMSCs-Exos-miR-150-3p. In a SONFH rat model, BMSCs-Exos-miR-150-3p alleviated ferroptosis in osteoblasts through BTRC/Nrf2. In addition, Gfi1 bonded to the miR-150-3p promoter and inhibited its transcription. Gfi1 silencing elevated miR-150-3p levels and improves cell viability of BMSCs. In conclusion, our results suggest that BMSCs-Exos-miR-150-3p alleviates SONFH by suppressing ferroptosis through the regulation of BTRC/Nrf2 and miR-150-3p may be a potential target for SONFH treatment.

Receptor-mediated signaling could be modulated by ubiquitination of pathway intermediates, but the role of such modification in the pathogenesis of inflammation and inflammation-related cancer is lesser known. The ubiquitin ligase Pellino1 has been shown to modulate immune signals by enabling various immune cells to respond to their receptor signals effectively. Here, we show that Pellino1 levels are elevated in patients with colitis, patients with colitis-associated colon cancer (CAC), and murine models of these conditions. In a monocyte-specific Pellino1 knock-out mouse model, we find reduced macrophage migration and activation, leading to attenuated development of colitis and CAC in male mice. Mechanistically, Pellino1 targets STAT3 for lysine 63-mediated ubiquitination, resulting in pathogenic activation of STAT3 signaling. Taken together, our findings reveal a macrophage-specific ubiquitination signaling axis in colitis and CAC development and suggest that Pellino1 is a potential candidate for treating chronic inflammation and inflammation-related cancer., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Background: Renal tubular injury (RTI) is one of the key characteristics of diabetic nephropathy (DN). Penehyclidine hydrochloride (PHC) was an anticholinergic drug with renoprotective effects, but its specific mechanism in the treatment of DN was still unclear., Methods: We treated different diabetic mouse models and high glucose-induced RTI models by PHC. Histological analyses were performed using flow cytometry and staining, and ELISA evaluated the ROS, apoptosis, and related markers under different treatments. The molecular interactions were analyzed by ChIP, dual-luciferase reporter, and CoIP., Results: PHC alleviated RTI by activating mitophagy and inhibiting apoptosis, and the protective effect could be rescued by PARK2 knockdown. Nrf2 bound to the promoter region of PARK2 and promoted its expression. PHC reduced the level of apoptosis by reducing the degree of nuclear translocation of AIFM1, which was rescued by PARK2 knockdown. PARK2 knockdown reduced the non-degradative ubiquitination of AIFM1, thus promoting its nuclear translocation and ultimately facilitating renal tubular cells (RTCs) apoptosis. The over-expression of AIFM1 rescued the RTCs apoptosis antagonized by PHC., Conclusions: PHC activated Nrf2 to up-regulate PARK2 transcription to induce mitophagy and inhibit apoptosis mediated by nuclear translocation of AIFM1 through promoting non-degradative ubiquitination of AIFM1, ultimately rescuing RTI in DN., Competing Interests: Competing interests The authors declare that there is no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The influenza A virus evades the host innate immune response to establish infection by inhibiting RIG-I activation through its nonstructural protein 1 (NS1). Here, we reported that receptor-transporting protein 4 (RTP4), an interferon-stimulated gene (ISG), targets NS1 to inhibit influenza A virus infection. Depletion of RTP4 significantly increased influenza A virus multiplication, while NS1-deficient viruses were unaffected. Mechanistically, RTP4 interacts with NS1 in an RNA-dependent manner and sequesters it from the TRIM25-RIG-I complex, thereby restoring TRIM25-mediated RIG-I K63-linked ubiquitination and subsequent activation of IRF3. Antiviral activity of RTP4 requires the evolutionarily conserved CXXC motifs and an H149 residue in the zinc finger domain, mutations of which disrupted RTP4-NS1 interaction and abrogated the ability of RTP4 to rescue RIG-I-mediated signaling. Collectively, our findings provided insights into the mechanism by which an ISG restricts influenza A virus replication by reactivating host antiviral signaling., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Inc. All rights reserved.)

Background: Aging is a complex biological process that disrupts tissue structure and impairs physiological function, which contributes to the development of age-related diseases such as cardiovascular disorders. However, effective treatment strategies are lacking., Objective: To investigate the geroprotective effects of Lycium barbarum glycopeptide (LbGp) and its potential mechanisms in a D-galactose-induced accelerated aging mouse model., Methods: Mice were subcutaneously injected with D-galactose (500 mg/kg/day) for 12 weeks to induce aging, while LbGp was orally administered (100 mg/kg/day) throughout the study. The geroprotective effects of LbGp were assessed by behavioral tests, cardiac echocardiography, pathohistological and transcriptomic analyses. Transmission electron microscopy was used to observe the ultrastructure of mitochondria. Mitochondrial stress assays and JC-1 fluorescent probe were conducted to evaluate mitochondrial function. Flow cytometer and western blot were performed to assess mitophagy flux., Results: LbGp treatment improved the aging phenotypes of D-galactose-induced mice, with a pronounced enhancement in cardiac function compared to neurocognitive and skeletal muscle functions. Transcriptome analysis indicated that LbGp ameliorated energy metabolism in the heart. Mitochondrial assays revealed LbGp improved mitochondrial function and preserved structural integrity of the mitochondrial inner membrane. LbGp attenuated mitochondrial fission and restored impaired PINK1/Parkin-mediated mitophagy pathway caused by D-galactose in cardiomyocytes., Conclusion: LbGp can ameliorate aging phenotypes and enhance cardiac metabolism by activating the PINK1/Parkin-mediated mitophagy pathway in D-galactose-induced mice. These findings underscore its potential as a therapeutic agent for aging and aging-related cardiovascular diseases., Competing Interests: Declaration of competing interest The authors declare no competing interests. Conflicts of interest The authors have no conflicts of interest to declare., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

Prcis: Alterations in the PTEN-induced kinase 1 (PINK)-mediated mitophagy pathway play an important role in pseudoexfoliation syndrome (PEX) disease., Purpose: PEX is a condition in which aberrant fibrillary protein builds up in various components of the eye and other extraocular tissues. In this study, we aim to investigate the functionality of intracellular auto-degradative machinery-especially mitophagy-and related genes and proteins in PEX., Materials and Methods: Anterior lens capsules were obtained from cataract patients with and without PEX to constitute the PEX group and age-matched controls during microincision cataract surgery. PINK1-mediated mitophagy markers were evaluated on the transcriptional and translational level via reverse transcriptionquantitative polymerase chain reaction and immunohistochemistry analysis, respectively., Results: The lens epithelial cells of PEX patients were characterized by significantly higher PINK1 gene expression compared with that of the controls ( P <0.05). In terms of intensity of staining of expressed proteins, PINK1 ( P <0.05), Parkin ( P <0.01), and microtubule-associated protein 1A/1B-light chain 3 B ( P <0.01) were all statistically higher in PEX, compared with the controls., Conclusion: Altered auto-degradative response-specifically mitophagy-is a component of increased oxidative stress in PEX patients. The role of this mechanism in emerging complications warrants further research., Competing Interests: Disclosure: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

This study was dedicated to investigating the effects of microRNA-128-3p (miR-128-3p) on neuronal apoptosis and neurobehavior in cerebral palsy (CP) rats via the Smurf2/YY1 axis.In vivo modeling of hypoxic-ischemic (HI) CP was established in neonatal rats. Neurobehavioral tests (geotaxis reflex, cliff avoidance reaction, and grip test) were measured after HI induction. The HI-induced neurological injury was evaluated by HE staining, Nissl staining, TUNEL staining, immunohistochemical staining, and RT-qPCR. The expression of miR-128-3p, Smurf2, and YY1 was determined by RT-qPCR and western blot techniques. Moreover, primary cortical neurons were used to establish the oxygen and glucose deprivation (OGD) model in vitro, cell viability was detected by CCK-8 assay, neuronal apoptosis was assessed by flow cytometry and western blot, and the underlying mechanism between miR-128-3p, Smurf2 and YY1 was verified by bioinformatics analysis, dual luciferase reporter assay, RIP, Co-IP, ubiquitination assay, western blot, and RT-qPCR.In vivo, miR-128-3p and YY1 expression was elevated, and Smurf2 expression was decreased in brain tissues of hypoxic-ischemic CP rats. Downregulation of miR-128-3p or overexpression of Smurf2 improved neurobehavioral performance, reduced neuronal apoptosis, and elevated Nestin and NGF expression in hypoxic-ischemic CP rats, and downregulation of Smurf2 reversed the effects of downregulation of miR-128-3p on neurobehavioral performance, neuronal apoptosis, and Nestin and NGF expression in hypoxic-ischemic CP rats, while overexpression of YY1 reversed the effects of Smurf2 on neurobehavioral performance, neuronal apoptosis, and Nestin and NGF expression in hypoxic-ischemic CP rats. In vitro, downregulation of miR-128-3p effectively promoted the neuronal survival, reduced the apoptosis rate, and decreased caspase3 protein expression after OGD, and overexpression of YY1 reversed the ameliorative effect of downregulation of miR-128-3p on OGD-induced neuronal injury. miR-128-3p targeted to suppress Smurf2 to lower YY1 ubiquitination degradation and decrease its expression.Inhibition of miR-128-3p improves neuronal apoptosis and neurobehavioral changes in hypoxic-ischemic CP rats by promoting Smurf2 to promote YY1 ubiquitination degradation and reduce YY1 expression., Competing Interests: Declarations. Ethics Approval: The animal care procedures and animal experiments in the research were conducted under the ratification of the Animal Ethics Committee of Shanxi Provincial People’s Hospital (approval number: 20210415), and the handling of animals during the experiment was conducted in strict accordance with international ethical guidelines and national health guidelines regarding the maintenance and use of laboratory animals. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: This study aimed to explore the effects of Parkin (Prkn) knockout in a juvenile mouse model of asthma., Methods: Prkn knockout (KO) and wild type (WT) mice were utilized to establish a juvenile mouse asthma model. The asthma model involved exposure to hyperoxia/ovalbumin (OVA), encompassing hyperoxia from postnatal day 1 (P1) to P7, sensitization on P21 and P28, and challenge from P36 to P42. Room air/phosphate-buffered saline (PBS) served as the control condition. Following airway resistance measurement, bronchoalveolar lavage fluid (BALF) was collected for cellular analysis, and lung tissues were subjected to histological examination and oxidative stress assessment. Serum levels of ovalbumin-specific immunoglobulin E (IgE), total IgE, interleukin-4 (IL-4), IL-5, and IL-13 were quantified using enzyme-linked immunosorbent assay (ELISA)., Results: WT mice exposed to hyperoxia/OVA showed decreased body weight and increased airway resistance compared to those exposed to control condition. Conversely, KO mice exhibited increased body weight under asthma conditions. KO mice with asthma had reduced total cell counts, along with lower levels of lymphocytes, eosinophils, and neutrophils, compared to WT asthma mice. Histological assessment showed attenuated inflammation and reduced collagen deposition in KO mice relative to WT mice, with lower serum levels of inflammatory markers and improved lung oxidative stress profiles. No significant differences were observed between KO and WT mice under room air/PBS conditions., Conclusions: Parkin knockout in juvenile mice mitigates asthma-related alterations in airway resistance, histopathological changes, inflammation status, and oxidative stress. These findings highlight a protective role of Parkin deficiency against asthma-associated pathologies.

Breast cancer has become the leading cause of death in women. Membrane associated ring-CH-type finger 1 (MARCHF1) is associated with the development of various types of cancer, but the exact role of MARCHF1 in breast cancer remains unclear. In our study, the higher MARCHF1 expression was observed in tumor samples of patients with breast cancer and then the role of MARCHF1 in breast cancer was further evaluated. Overexpression of MARCHF1 contributed to proliferation of cancer cells and inhibition of oxidative stress. Knockdown of MARCHF1 reduced breast cancer cell proliferation, increased mitochondrial dysfunction induced by oxidative stress, eventually aggravating cell death. In vivo, MARCHF1 promoted the tumor growth and oppositely, MARCHF1 silencing suppressed the tumor development. Moreover, MARCHF1 interacted with repressor Element-1 silencing transcription factor (REST) and facilitated its ubiquitylation and degradation. Subsequently, REST negatively regulated the transcription of mitochondrial transcription factor A (TFAM). The subcutaneous tumor formation assay in nude mice also supported these conclusions. In details, knockdown of MARCHF1 upregulated the protein expression of REST and downregulated the mRNA level of TFAM. On the contrary, MARCHF1 overexpression exhibited opposite effects. Thus, MARCHF1 is conducive to the progression of breast cancer via promoting the ubiquitylation and degradation of RSET and then the transcription of TFAM. Downregulating MARCHF1 could provide a novel direction for treating breast cancer., (© 2024 International Federation for Cell Biology.)

Background: The activation of TGF-β pathway can facilitate tumorigenesis. Understanding the TGF-related genes (TRGs) in oral cancer and determining their prognostic value is of utmost importance., Methods: The TRGs were selected to develop a prognostic model based on lasso regression. Oral cancer patients were classified into high-risk and low-risk groups based on the risk model. Subsequently, multivariate COX regression was employed to identify the prognostic marker. Additionally, the expression of SMURF2 was validated using quantitative real-time polymerase chain reaction (qRT-PCR) and the Human Protein Atlas (HPA) database. To investigate the relationship between SMURF2 expression and immune cell infiltrations, we conducted single-sample Gene Set Enrichment Analysis (ssGSEA) analyses., Results: We identified 16 differentially expressed TRGs in oral cancer, all of which showed upregulation. From these, we selected eight TRGs as prognostic signatures. Furthermore, the high-risk group demonstrated lower infiltration levels of immune cells, immune score, and higher tumor purity. Interestingly, we also found that SMURF2 serves as an independent prognostic biomarker. SMURF2 was upregulated in oral cancer, as confirmed by public databases and qRT-PCR analysis. Importantly, our results indicate a close association between SMURF2 expression and the immune microenvironment., Conclusion: The 8-TRG signature prognosis model that we constructed has the ability to predict the survival rate and immune activity of oral cancer patients. SMURF2 could be effective in recognizing prognosis and evaluating immune efficacy for oral cancer., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interets: All authors declared that there was no conflict of interest., (© 2024. The Author(s).)

The ubiquitination or SUMOylation of hematopoietic-related factors plays pivotal roles in hematopoiesis. RNF111, known as a ubiquitin ligase, is a newly discovered SUMO-targeted ubiquitin ligase involved in multiple signaling pathways mediated by transforming growth factor (TGF)-β family members. However, its role in hematopoiesis remains unclear. Herein, a heritable Rnf111 mutant zebrafish line was generated by CRISPR/Cas9-mediated genome editing. Impairment of hematopoietic stem and progenitor cells (HSPC) of definitive hematopoiesis was found in Rnf111-deficient mutants. Ablation of Rnf111 resulted in decreased phosphorylation of Smad2/3 in HSPC. Definitive endoderm 2 inducer (IDE2), which specifically activates TGF-β signaling and downstream Smad2 phosphorylation, could restore definitive hematopoiesis in Rnf111-deficient embryos. Further molecular mechanism studies revealed that Gcsfr/NO signaling was an important target pathway of Smad2/3 involved in Rnf111-mediated HSPC development. In conclusion, our study demonstrated that Rnf111 contributes to the development of HSPC by maintaining Smad2/3 phosphorylation and activation of the Gcsfr/NO signaling pathway.

The intake of selenium (Se) in the human body is negatively correlated with the risk of colorectal cancer (CRC), but its mechanism in the occurrence and development of CRC is not clear. This study aimed to evaluate the therapeutic effect of Se on CRC, and explore the anti-tumor effect of Se supplementation on CRC and its molecular mechanism. In this study, we utilized colony formation assay, cell scratch test, Transwell migration, and flow cytometry to assess cell proliferation, migration, and apoptosis. Our findings demonstrate that Se effectively suppresses the growth and proliferation of CRC cell lines HCT116 and SW480 and promoting cellular apoptosis. In vivo experiments demonstrated a significant inhibitory effect of Se on tumor growth. CRC-related datasets were extracted from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases for differential expression analysis of TRIM32 and survival analysis. We found that TRIM32 was highly expressed in tumor tissues of CRC patients and correlated with a poor prognosis. Furthermore, through RNA sequencing analysis, we identified TRIM32 as a gene that was significantly decreased after Se treatment in HCT116 cells. This finding was subsequently validated by Western blot results. Moreover, TRIM32 knockdown combined with Se treatment significantly inhibited cell growth proliferation and migration and further induced apoptosis of colorectal cancer cells. In conclusion, our findings provided evidence that Se inhibited the growth of colorectal cancer cells by down-regulating TRIM32., Competing Interests: Declarations. Ethics Approval: The study was reviewed and approved by the Medical Ethics Committee of Southern Medical University (no. 2021–0024) and the Experimental Animal Ethics Committee of Southern Medical University (L2019074). Consent to Participate: All study participants signed informed consent. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Pyroptosis is an identified programmed cell death that has been highly linked to endoplasmic reticulum (ER) dynamics. However, the crucial proteins for modulating dynamic ER membrane curvature change that trigger pyroptosis are currently not well understood. In this study, a biotin-labeled chemical probe of potent pyroptosis inducer α-mangostin (α-MG) was synthesized. Through protein microarray analysis, reticulon-4 (RTN4/Nogo), a crucial regulator of ER membrane curvature, was identified as a target of α-MG. We observed that chemically induced proteasome degradation of RTN4 by α-MG through recruiting E3 ligase UBR5 significantly enhances the pyroptosis phenotype in cancer cells. Interestingly, the downregulation of RTN4 expression significantly facilitated a dynamic remodeling of ER membrane curvature through a transition from tubules to sheets, consequently leading to rapid fusion of the ER with the cell plasma membrane. In particular, the ER-to-plasma membrane fusion process is supported by the observed translocation of several crucial ER markers to the "bubble" structures of pyroptotic cells. Furthermore, α-MG-induced RTN4 knockdown leads to pyruvate kinase M2 (PKM2)-dependent conventional caspase-3/gasdermin E (GSDME) cleavages for pyroptosis progression. In vivo, we observed that chemical or genetic RTN4 knockdown significantly inhibited cancer cells growth, which further exhibited an antitumor immune response with anti-programmed death-1 (anti-PD-1). In translational research, RTN4 high expression was closely correlated with the tumor metastasis and death of patients. Taken together, RTN4 plays a fundamental role in inducing pyroptosis through the modulation of ER membrane curvature remodeling, thus representing a prospective druggable target for anticancer immunotherapy., (© The Author(s) 2024. Published by Oxford University Press on behalf of Higher Education Press.)

DELAY OF GERMINATION1 (DOG1) is a critical regulator of seed dormancy and seed thermoinhibition. However, how DOG1 expression is regulated by post-translational modifications and how seeds transmit the high-temperature signal to DOG1 remain largely unknown. ALFIN1-like 6/7 (AL6/7) was previously found to repress DOG1 expression during seed imbibition. Here, we found that AL6/7 represses seed dormancy partly by downregulating DOG1 expression. AtSIZ1, a SUMO E3 ligase, interacts with AL6 and mediates its SUMOylation mainly at the lysine 181 residue. SIZ1-mediated SUMOylation of AL6 is required for repression of DOG1 transcription and seed dormancy. SUMOylation of AL6 is required for its association with the DOG1 locus and protects it from ubiquitination and subsequent 26S proteasome-mediated protein degradation. High temperatures decrease SUMOylation levels of AL6, resulting in downregulation of AL6 protein levels and an increase in DOG1 transcription, which consequently causes reduced seed germination. Taken together, these results demonstrate that reversible SUMOylation of AL6 fine-tunes DOG1 expression, which is required for precise establishment of seed dormancy and inhibition of seed germination under high-temperature conditions in Arabidopsis thaliana., (© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.)

Mitophagy serves as a mitochondrial quality control mechanism to maintain the homeostasis of mitochondria and the intracellular environment. Studies have shown that there is a close relationship between mitophagy and apoptosis. Sestrin2 (Sesn2) is a highly conserved class of stress-inducible proteins that play important roles in reducing oxidative stress damage, inflammation, and apoptosis. However, the potential mechanism of how Sesn2 regulates mitophagy and apoptosis in severe acute pancreatitis (SAP) remains unclear. In the study, RAW264.7 (macrophage cell Line) cellular inflammation model established by lipopolysaccharide (LPS) treatment as well as LPS and CAE-induced SAP mouse model (wild-type and Sen2 Knockout mouse) were used. Our study showed that LPS stimulation significantly increased the level of Sesn2 in RAW264.7 cells, Sesn2 increased mitochondrial membrane potential, decreased inflammation levels, mitochondrial superoxide levels and apoptosis, and also promoted monocyte macrophages toward the M2 anti-inflammatory phenotype, suggesting a protective effect of Sesn2 on mitochondria. Further, Sesn2 increased mitophagy and decreased apoptosis via modulating the PINK1-Parkin signaling. Meanwhile, knockout of Sesn2 exacerbated pancreatic, mitochondrial damage and inflammation in a mouse model of SAP. In addition, the protective effect of Sesn2 against SAP was shown to be associated with mitophagy conducted by the PINK1-Parkin pathway via inhibiting apoptosis. These findings reveal that Sesn2 in balancing mitochondrial autophagy and apoptosis by modulating the PINK1-Parkin signaling may present a new therapeutic strategy for the treatment of SAP., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Ubiquitination is a major post-translational regulatory mechanism that tunes numerous aspects of ubiquitinated target proteins, including localization, stability, and function. During differentiation and myelination, Oligodendrocytes (OLs) in the central nervous system and Schwann cells (SCs) in the peripheral nervous system undergo major cellular changes, including the tightly controlled production of large and accurate amounts of proteins and lipids. Such processes have been implied to depend on regulatory aspects of ubiquitination, with E3 ubiquitin ligases being generally involved in the selection of specific ubiquitination substrates by ligating ubiquitin to targets and granting target selectivity. In this study, we have used multiple transgenic mouse lines to investigate the functional impact of the E3 ubiquitin ligase Nedd4 in the OL- and SC-lineages. Our findings in the developing spinal cord indicate that Nedd4 is required for the correct accumulation of differentiated OLs and ensures proper myelination, supporting and further expanding previously suggested conceptual models. In sciatic nerves, we found that Nedd4 is required for timely radial sorting of axons by SCs as a pre-requirement for correct onset of myelination. Moreover, Nedd4 ensures correct myelin thickness in both SCs and spinal cord OLs., (© 2024 The Author(s). GLIA published by Wiley Periodicals LLC.)

Male sterility is an important agronomical trait in self-pollinating plants for producing cost-effective F1 hybrids to harness the heterosis. Still, large-scale development and maintenance of male sterile lines and restoring fertility in F1 hybrids pose significant challenges in plant hybrid breeding. Cotton is a self-pollinating crop and exhibits strong hybrid vigor. However, there are currently few breeding methods to achieve cost-effective production of F1 hybrid cotton. Here, we utilized novel functions of the Arabidopsis autophagy-related BECLIN1/ATG6 and a mutant of E3 ubiquitin ligase COP1 (COP1 L105A ) genes in developing rescuable male sterility in cotton. We have generated multiple male-sterile (MS) and restorer (RS) cotton lines expressing BECLIN1 and COP1 L105A , respectively. Cytological observation showed that post-meiotic tapetal expression of BECLIN1 delays tapetum developmental programmed cell death (dPCD) by affecting reactive oxygen species (ROS) balance-this delay in dPCD results in early microspore defects and later small-sized flowers with indehiscent anthers. Furthermore, the evaluation of F1 hybrids developed by crossing MS and RS lines showed that early tapetal COP1 L105A expression abolishes expression of BECLIN1 resulting in normal tapetum degeneration, pollen development, and fertility. In addition, the F1 hybrid developed with MS and RS cotton lines in transgenic glass-house and net-house conditions showed the rescued fertility comparable with control plants (WT). In terms of cotton fiber productivity, the COP1 L105A -expressing transgenic cotton lines outperformed the WT. The current work effectively demonstrates the wider applicability of the new F1 cotton production system., (© 2024 The Author(s). Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.)

Hypopharyngeal and laryngeal cancers which belong to head and neck squamous cell carcinoma (HNSCC) are the two most malignant types of head and neck cancer, characterized by a low 5-year survival rate, high recurrence and metastasis rate. It is vital to explore strategies to suppress metastasis and improve prognosis for patients with these cancers. In this research, we analyzed the clinical data and found that E3 ubiquitin ligase TRIM47 was upregulated in cancer tissues of hypopharyngeal cancer and was closely associated with poor survival outcomes. In terms of mechanism, we performed tandem affinity chromatography and denatured Ni-NTA Agarose pulldown. As a result, TRIM47 was found to interact with vimentin and control vimentin stabilization through ubiquitination, specifically in the form of K63 chains. Importantly, through experiments of cancer cell viability and migration, we found that TRIM47 could enhance the proliferation and metastasis abilities of cancer cells in a vimentin-dependent manner, thus promoting the advancement of hypopharyngeal and laryngeal cancers. TRIM47 was verified to regulate cancer cells metastasis in vivo using metastasis models. All these results imply that TRIM47 emerges as a potential biomarker for early diagnosis and metastasis prediction of hypopharyngeal and laryngeal cancers and represents a promising therapeutic target., (© 2024 The Author(s). Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a chronic condition encompassing metabolic dysfunction-associated steatotic liver (MASL) and metabolic dysfunction-associated steatohepatitis (MASH), which can progress to fibrosis, cirrhosis, or hepatocellular carcinoma (HCC). The heterogeneous and complex nature of MASLD complicates optimal drug development. Ebastine, an antihistamine, exhibits antitumor activity in various types of cancer. However, its effects on MASH remain unexplored. In the present study, we identified ebastine as a potential treatment for MASH. Our results indicated that ebastine acts as a novel MKRN1 inhibitor by promoting MKRN1 destabilization through self-ubiquitination, leading to AMP-activated protein kinase (AMPK) activation. Ebastine appeared to bind to the C-terminal domain of MKRN1, particularly at residues R298 and K360. Notably, Mkrn1 knockout (KO) mice demonstrated resistance to MASH, including obesity, steatosis, inflammation, and fibrosis under high-fat-high-fructose diet (HFHFD) conditions. Additionally, liver-specific Mkrn1 knockdown using AAV8 alleviated MASH symptoms in HFHFD-fed mice, implicating MKRN1 as a potential therapeutic target. Consistent with these findings, treatment with ebastine significantly reduced the risk of MASH in HFHFD-fed mice, with a decrease in MKRN1 expression and an increase in AMPK activity. Our study suggests that ebastine binds to MKRN1, promoting its destabilization and subsequent degradation by stimulating its ubiquitination. This enhances AMPK stability and activity, suppressing lipid accumulation, inflammation, and fibrosis. Moreover, the knockout of Mkrn1 mice decreased the risk of MASH, suggesting that ebastine could be a promising therapeutic agent for the treatment of MASH., Competing Interests: Declarations. Conflict of interests: The authors declare no competing interests. Ethical approval and consent to participate: The Institutional Animal Care and Use Committees (IACUC) of the Laboratory Animal Research Center at Yonsei University conducted a comprehensive review and approved all procedures utilized in this study. (IACUC-A-201810-802-02). Consent for publication: Not applicable., (© 2025. The Author(s).)

The Vpx protein encoded by HIV-2/simian immunodeficiency virus (SIV) can antagonize the restriction of the host intrinsic restriction factor, SAMHD1, in nondividing cells by promoting its polyubiquitination and subsequent degradation, thereby facilitating viral replication and immune evasion. However, the role of deubiquitinating enzymes (DUBs) in the dynamics of virus and host remains poorly understood. Here, we demonstrate that DUB USP37 significantly reverses the Vpx-mediated degradation of SAMHD1 in various HIV-2/SIV subtypes by interacting with SAMHD1 and removing its ubiquitin chains. Notably, USP37 deubiquitinates SAMHD1 by directly recognizing SAMHD1 rather than by targeting the E3 ubiquitin ligase. The deubiquitinase activity of USP37 and its ubiquitin interacting motifs are essential for the deubiquitination of SAMHD1, whereas the phosphorylation state of USP37 does not influence its activity. Additionally, USP37 enhances the suppression of the retrotransposition of LINE-1 elements by SAMHD1 via stabilizing SAMHD1. Our findings provide important evidence that enhancing the deubiquitinating activity of some DUBs results in the stability of the host restriction factor and might be a viable strategy against HIV/SIV infections.IMPORTANCESAMHD1 is a multifunctional protein, including restricting virus replication, maintaining genomic integrity through DNA repair, modulating the immune response by influencing the production of type I interferons and other cytokines, and affecting cancer cell proliferation and sensitivity to chemotherapy. However, HIV-2/simian immunodeficiency virus (SIV)-encoded Vpx and the host E3 ligase TRIM21 can induce the degradation of SAMHD1 via the ubiquitin-proteasome pathway. Therefore, it is necessary to find the strategy to stabilize SAMHD1. Our study demonstrates that the deubiquitinase USP37 reverses Vpx- and TRIM21-mediated degradation of SAMHD1, thereby inhibiting SIV replication and LINE-1 activity by stabilizing SAMHD1. Thus, we report a novel role of USP37, which represents a potentially useful target for the development of new drugs., Competing Interests: The authors declare no conflict of interest.

HIV-1 can integrate viral DNA into host cell chromosomes and establish a long-term stable latent viral reservoir, a major obstacle in curing HIV-1 infection. The reactivation of latent proviruses with latency-reversing agents (LRAs) is a prerequisite for the eradication of viral reservoirs. Previous reports have shown that tannic acid (TA) exerts several biological functions, including antioxidant and antitumor activities. Here, we identified a novel function of TA as a reactivator of HIV-1 latency. TA showed similar features to the HIV-1 transactivator of transcription (Tat) and was able to reactivate a larger number of proviruses from various integration sites. TA also showed a strong synergistic effect with other LRAs acting on different signaling pathways. Further studies revealed that the polycomb repressive complex 1 component, chromobox protein homolog 4 (CBX4), is specifically degraded by TA through ubiquitination. CBX4 is associated with the tri-methylation at lysine 27 of histone H3 (H3K27me3) which was enriched on HIV-1 long terminal repeat regions. The TA-induced CBX4 degradation decreased the H3K27me3 enrichment and subsequently enhanced the transcriptional activity of the integrated proviruses. These results suggest that TA is an efficient LRA aiming to a new target for HIV-1 latency, which could be developed to eradicate latent proviruses.IMPORTANCEHIV-1 remains a global health challenge, with its ability to integrate into the host genome and evade the effects of drugs. To overcome this obstacle, the "shock and kill" strategy was proposed, targeting the reactivation of latent HIV-1 for subsequent eradication through antiretroviral medication and immune system reinforcement. Here, we found a new reactivator for HIV-1 latency, tannic acid (TA), which can reactivate HIV-1 latency widely and deeply. Moreover, we demonstrated that TA could promote the interaction between the polycomb repressive complex 1 component CBX4 and the E3 ubiquitin ligase cullin 4A (CUL4A), resulting in CBX4 degradation through the ubiquitin-proteasome system. These events reduce H3K27me3 enrichment in the HIV-1 long terminal repeat region, thereby promoting HIV-1 transcription and ultimately reactivating HIV-1 latent infection. Our work may facilitate the identification of new latency-reversing agents and provide more theoretical evidence for the molecular mechanism of HIV-1 latency., Competing Interests: The authors declare no conflict of interest.

E3 ligases are essential for ubiquitination and play a role in regulating various aspects of eukaryotic life. Ariadne (ARI) proteins, a subfamily of RBR (RING-between-RING) proteins, have been recognized as a new class of RING-finger E3 ligases. Recent research has shed light on their potential involvement in plants' responses to abiotic stress. However, comprehensive studies on ARI genes in apple (Malus domestica) are still lacking. This study identified ten MdARI genes in the apple genome, and examined intraspecific and interspecific collinearity to explore the evolutionary relationships of ARI family members. Phylogenetic analyses classified MdARIs into two subfamilies (A and B), and by integrating gene structure, conserved motifs, and sequence comparison results, subfamily B was further divided into two subgroups (I and II). Tissue expression analyses revealed varied expression patterns of MdARI genes in different tissues, and subcellular localization showed that MdARI1-1, MdARI1-2, and MdARI9-1 were located in the nucleus, while the other seven MdARIs were distributed throughout the cell. Analyses of promoter cis-elements and expression patterns under cold, salt, and drought treatments indicated the involvement of MdARIs in abiotic stress responses. Several proteins crucial to the plant stress response were predicted to be potential MdARIs-interacting proteins based on the protein interaction network. Additionally, the interaction between UBC11 (E2) and MdARI7-2 was confirmed by a yeast two-hybrid (Y2H) experiment, suggesting that MdARI7-2 may function as an E3. These findings will greatly benefit future research on the role and mechanisms of ARI proteins in apple stress response., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: The protein cereblon (CRBN) mediates the antileukemia effect of lenalidomide (Len). Len binds to CRBN, recruits IKZF1/IKZF3, and promotes their ubiquitination and degradation, through which Len exhibits its antileukemia and antimyeloma activity. Therefore, the protein level of CRBN might affect the antiproliferative effect of Len. In this study, we explored the interactome for CRBN using proximity labeling technique TurboID and quantitative proteomics, and then investigated the antileukemia effect of Len., Methods: The primary acute myeloid leukemia (AML) cells and AML cell lines were used to explore the functions of histone demethylase KDM5C on the antileukemia effect of Len. The cell viability and CRBN protein levels were evaluated in these cell lines. In addition, the KDM5C inhibitors were used to determine the effects of KDM5C enzymatic activity on the viability of AML cell lines., Results: We identified that histone demethylase KDM5C was a CRBN-interacting protein. Biochemical experiments found that the CRBN-interacting protein KDM5C could stabilize CRBN and enhance the antileukemia effect of Len in an enzyme activity-independent manner. Furthermore, our studies revealed that the small-molecule compound MLN4924 could increase CRBN by elevating KDM5C.The combination of MLN4924 and Len can further increase the sensitivity of primary AML cells and AML cell lines to Len., Conclusions: This study provides a possible strategy for a combination treatment with MLN4924 and Len for leukemia., Competing Interests: Declarations. Ethics approval and consent to participate: The bone marrow sample from patient was acquired in compliance with the Helsinki Declaration and approved by the Ethics Committee of the Second Affiliated Hospital of Soochow University (Approval No: SUDA20240522H04, date 1 November 2024). Competing interests: The authors declare that there are no competing of interest related to the contents of this article., (© 2025. The Author(s).)

Effective modulation of gene expression in plants is achievable through tools like CRISPR and RNA interference, yet methods for directly modifying endogenous proteins remain lacking. Here, we identify the E3 ubiquitin ligase E3TCD1 and develope a Targeted Condensation-prone-protein Degradation (TCD) strategy. The X-E3TCD1 fusion protein acts as a genetically engineered degrader, selectively targeting endogenous proteins prone to condensation. For example, a transgenic E3TCD1 fusion with Teosinte branched 1 (TB1) degrades the native TB1 protein, resulting in increased tiller numbers in rice. Additionally, conditional degradation of the negative defense regulator Early Flowering 3 via a pathogen-responsive Pro TBF1 -uORFs TBF1 cassette enhances rice blast resistance without affecting flowering time in the absence of pathogen. Unlike prevailing targeted protein degradation strategies, the TCD system does not rely on small molecules, antibodies, or genetic knock-in fusion tags, demonstrating its promise as a transgene-based approach for optimizing crop performance., Competing Interests: Competing interests: A patent with the application number 2024116014154 using all data generated from this study has been filed by Wuhan University, listing G.X., M.L., and Q.W. as inventors. Other authors claim no competing interests., (© 2025. The Author(s).)

Stalled ribosomes cause collisions, impair protein synthesis, and generate potentially harmful truncated polypeptides. Eukaryotic cells utilize the ribosome-associated quality control (RQC) and no-go mRNA decay (NGD) pathways to resolve these problems. In yeast, the E3 ubiquitin ligase Hel2 recognizes and polyubiquitinates disomes and trisomes at the 40S ribosomal protein Rps20/uS10, thereby priming ribosomes for further steps in the RQC/NGD pathways. Recent studies have revealed high concentrations of disomes and trisomes in unstressed cells, raising the question of whether and how Hel2 selects long-term stalled disomes and trisomes. This study presents quantitative analysis of in vivo-formed Hel2•ribosome complexes and the dynamics of Hel2-dependent Rps20 ubiquitination and Ubp2/Ubp3-dependent deubiquitination. Our findings show that Hel2 occupancy progressively increases from translating monosomes to disomes and trisomes. We demonstrate that disomes and trisomes with mono- or di-ubiquitinated Rps20 resolve independently of the RQC component Slh1, while those with tri- and tetra-ubiquitinated Rps20 do not. Based on the results, we propose a model in which Hel2 translates the duration of ribosome stalling into polyubiquitin chain length. This mechanism allows for the distinction between transient and long-term stalling, providing the RQC machinery with a means to select fatally stalled ribosomes over transiently stalled ones., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Mitochondrial quality control is crucial for the homeostasis of the mitochondrial network. The balance between mitophagy and biogenesis is needed to reduce cerebral ischemia-induced cell death. Ischemic preconditioning (IPC) represents an adaptation mechanism of CNS that increases tolerance to lethal cerebral ischemia. It has been demonstrated that hypoxia-induced Seven in absentia Homolog 2 (Siah2) E3-ligase activation influences mitochondrial dynamics promoting the degradation of mitochondrial proteins. Therefore, in the present study, we investigated the role of Siah2 in the IPC-induced neuroprotection in in vitro and in vivo models of IPC. To this aim, cortical neurons were exposed to 30-min oxygen and glucose deprivation (OGD, sublethal insult) followed by 3 h OGD plus reoxygenation (lethal insult). Our results revealed that the mitochondrial depolarization induced by hypoxia activates Siah2 at the mitochondrial level and increases LC3-II protein expression, a marker of mitophagy, an effect counteracted by the reoxygenation phase. By contrast, hypoxia reduced the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), a marker of mitochondrial biogenesis, whereas its expression was increased after reoxygenation thus improving mitochondrial membrane potential, mitochondrial calcium content, and mitochondrial morphology, hence leading to neuroprotection in IPC. Furthermore, Siah2 silencing confirmed these results. Collectively, these findings indicate that the balance between mitophagy and mitochondrial biogenesis, due to the activation of the Siah2-E3-ligase, might play a role in IPC-induced neuroprotection., Competing Interests: Competing interests: The authors declare no competing interests. Ethics approval: All methods were performed in accordance with the relevant guidelines and regulations. All animal experiments were performed according to the Guide for the Care and Use of Laboratory Animals and approved by the Animal Care Committee of “Federico II”, University of Naples, Italy, reference/registration number Aut. 318-2016-PR C3CA2.1. Not applicable to humans since there are no human subjects or samples in this study., (© 2025. The Author(s).)

Oxidative stress-associated proximal tubular cells (PTCs) damage is an important pathogenesis of hypertensive renal injury. We previously reported the protective effect of VEGFR3 in salt-sensitive hypertension. However, the specific mechanism underlying the role of VEGFR3 in kidney during the overactivation of the renin-angiotensin-aldosterone system remains unclear. In the present study, hypertensive nephropathy was established by angiotensin II (Ang II). We found that VEGFR3 was highly increased in PTCs of Ang II-infused mice. Activation of VEGFR3 mitigated renal dysfunction, pathological damage, and oxidative stress in Ang II-induced hypertensive mice. Moreover, we found that VEGFR3 restored mitophagy deficiency induced by Ang II both in vivo and in vitro to alleviate oxidative stress injury in PTCs. Furthermore, in vitro experiment demonstrated that VEGFR3 improved abnormal mitophagy by enhancing PARKIN mitochondrial translocation. LC-MS/MS and Co-IP assays identified HSPA1L as the interacted protein of VEGFR3, which promoted the mitochondrial translocation of PARKIN. Mechanistically, VEGFR3 disorder domain bound to HSPA1L, and crotonylation modification of HSPA1L at K130 by VEGFR3 was required for mitophagy regulation in the context of Ang II-induced PTCs. Finally, the protective effect of VEGFR3 on mitophagy and oxidative stress were attenuated by transfection K130 (HSPA1L-K130R) mutant plasmid in vivo and in vitro. These findings indicated that VEGFR3 alleviated oxidative stress by promoting PARKIN-dependent mitophagy pathway via regulating HSPA1L crotonylation at K130 site in Ang II-induced PTCs, which provided a mechanistic basis for the therapeutic target in hypertensive renal injury., Competing Interests: Declarations. Ethics approval and consent to participate: All animal experiments were approved by the Institutional Animal Care and Use Committee at the Second Affiliated Hospital of Harbin Medical University (SYDW2022-075). Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Transcripts of the KRAS locus are alternatively spliced to generate two proteins, KRAS4A and KRAS4B, which differ in their membrane-targeting sequences. These splice variants have been conserved for more than 450 million years, suggesting non-overlapping functions driven by differential membrane association. Here, we use proximity labeling to map the differential interactomes of the KRAS splice variants. We find 24 and 10 proteins that interact specifically with KRAS4A or KRAS4B, respectively. The KRAS interacting protein most specific to KRAS4A is BIRC6, a large member of the inhibitor of apoptosis protein family unique in possessing E2/E3 ubiquitin ligase activity. We find that this interaction takes place on the Golgi apparatus and results in the mono- and di-ubiquitination of KRAS4A at lysines 128 and 147. Silencing BIRC6 diminishes GTP loading of and growth stimulation by KRAS4A but not KRAS4B. Thus, BIRC6 is a ubiquitin ligase that inhibits apoptosis and also modifies KRAS4A., Competing Interests: Declaration of interests E.S.F. is a founder, scientific advisory board (SAB) member, and equity holder of Civetta Therapeutics, Proximity Therapeutics, Stelexis Biosciences, and Neomorph, Inc. (also board of directors). He is an equity holder and SAB member for Avilar Therapeutics, Photys Therapeutics, and Ajax Therapeutics and an equity holder in Lighthorse Therapeutics and Anvia Therapeutics. E.S.F. is a consultant to Novartis, EcoR1 capital, Odyssey, and Deerfield. The Fischer lab receives or has received research funding from Deerfield, Novartis, Ajax, Interline, Bayer, and Astellas., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Renal fibrosis is widely recognized as the ultimate outcome of many chronic kidney diseases. The process of epithelial-mesenchymal transition (EMT) plays a critical role in the progression of fibrosis following renal injury. UHRF1, as a critical epigenetic regulator, may play an essential role in the pathogenesis and progression of renal fibrosis and EMT. However, the potential mechanisms remain to be elucidated. We aim to investigate the role of UHRF1 in EMT and renal fibrosis and to evaluate the potential benefits of Hinokitiol in preventing renal fibrosis. Based on data from the GEO and Nephroseq databases, UHRF1 exhibited high expression levels in the unilateral ureteral obstruction (UUO) model and in patients with nephropathy. Gene set enrichment analysis predicted that UHRF1 may function through the TGF-β signaling pathway in fibrosis. By establishing a TGF-β1-stimulated HK2 cell model and animal models of renal fibrosis induced by UUO and folic acid, we confirmed that UHRF1 was highly expressed in both in vitro and in vivo models of renal fibrosis. After knockdown of UHRF1 in vitro, we found that the TGF-β/SMAD signaling pathway was inhibited, renal tubular epithelial cell EMT was reduced and renal fibrosis was attenuated. Hinokitiol has been reported to reduce the expression of UHRF1 mRNA and protein. We observed that inhibition of UHRF1 with Hinokitiol ameliorated induced EMT and renal fibrosis by reducing SMAD2/3 phosphorylation in vivo and in vitro. Taken together, our data demonstrated that the upregulation of UHRF1 accelerated the EMT of renal tubular cells and renal fibrosis through the TGF-β/SMAD signaling pathway. Hinokitiol may ameliorate renal fibrosis by suppressing the expression of UHRF1 in the kidney., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethics approval and consent to participate: The animal experience was approved by the Ethics Committee of Zhongnan Hospital of Wuhan University (approval number: ZN2022182). All experiments were performed at the Animal Research Center of Zhongnan Hospital of Wuhan University. Human kidney tissues (n = 6) used in this study were obtained from the Department of Urology, Zhongnan Hospital of Wuhan University. The hospital’s ethical review board approved the study and all samples were obtained after patients signed informed consent., (© 2025. The Author(s).)

NF2-related schwannomatosis, previously known as neurofibromatosis type 2, is a genetic disorder characterized by nerve tumors due to NF2 gene mutations. Mice with Nf2 deletion develop schwannomas slowly with low penetrance, hence inconvenient for preclinical studies. Here, we show that NF2, by recruiting E3 ubiquitin ligases β-TrCP1/2, promotes WWC1-3 ubiquitination and degradation. In NF2 mutated cells, WWC1-3 accumulation is a compensatory mechanism to prevent YAP/TAZ hyperactivation and rapid tumorigenesis. Accordingly, we generate a synthetic mouse model with complete penetrance and short latency by concurrently deleting Nf2 and Wwc1/2 in Schwann cells. This model closely resembles NF2-related schwannomatosis in patients, as confirmed by histological and single-cell transcriptome analysis. Moreover, a cell line from mouse schwannomas and a syngeneic tumor model in immune-competent mice are established. Furthermore, a screen using established models has identified candidate drugs that effectively suppress schwannoma progression. Hence, this work has developed rapid and transplantable models that will facilitate both basic and translational research on NF2-related schwannomatosis.

Osteoporosis is a systemic skeletal disorder characterized by reduced bone density and an increased risk of fractures, particularly prevalent in the aging population. Osteoporotic complications, including vertebral compression fractures, hip fractures, and distal forearm fractures, affect over 8.9 million individuals globally, placing a significant economic strain on healthcare systems. Recent advances have expanded our understanding of the mechanisms underlying osteoporosis, particularly the intricate regulatory networks involved in bone metabolism. A central player in these processes is ubiquitin-mediated proteasomal degradation, a crucial post-translational modification system that involves ubiquitin, the ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzyme (E2), ubiquitin ligase (E3), deubiquitinating enzymes, and the proteasome. Among the various E3 ligases, the NEDD4 family has emerged as a key regulator of both bone development and osteoporotic pathology. This review delineates the role of NEDD4 family in osteoporosis and identifies potential drug targets within these pathways, offering insights into novel therapeutic approaches for osteoporosis through targeted intervention., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Conflict of interest: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2025. The Author(s).)

Background: Cutaneous leiomyosarcoma (cLMS) is a rare soft-tissue neoplasm, showing smooth muscle differentiation, that arises from the mesenchymal cells of the dermis. To date, genetic investigation of these tumours has involved studies with small sample sizes and limited analyses that identified recurrent somatic mutations in RB1 and TP53, copy number gain of MYOCD and IGF1R, and copy number loss of PTEN., Objectives: To better understand the molecular pathogenesis of cLMS, we comprehensively explored the mutational landscape of these rare tumours to identify candidate driver events., Methods: In this retrospective, multi-institutional study, we performed whole-exome sequencing and RNA sequencing in 38 cases of cLMS., Results: TP53 and RB1 were identified as significantly mutated and thus represent validated driver genes of cLMS. COSMIC mutational signatures SBS7a/b and DBS1 were recurrent; thus, ultraviolet light exposure may be an aetiological factor driving cLMS. Analysis of significantly recurrent somatic copy number alterations, which represent candidate driver events, found focal (< 10 Mb) deletions encompassing TP53 and KDM6B, and amplifications encompassing ZMYM2, MYOCD, MAP2K4 and NCOR1. A larger (24 Mb) recurrent deletion encompassing CYLD was also identified as significant. Significantly recurrent broad copy number alterations, involving at least half of a chromosome arm, included deletions of 6p/q, 10p/q, 11q, 12q, 13q and 16p/q, and amplification of 15q. Notably PTEN is located on 10q, RB1 on 13q and IGFR1 on 15q. Fusion gene analysis identified recurrent CRTC1/CRTC3::MAML2 fusions, as well as many novel fusions in individual samples., Conclusions: Our analysis of the largest number of cases of cLMS to date highlights the importance of large cohort sizes and exploration beyond small targeted gene panels when performing molecular analyses, as it allowed a comprehensive exploration of the mutational landscape of these tumours and identification of novel candidate driver events. It also uniquely afforded the opportunity to compare the molecular phenotype of cLMS with LMS of other tissue types, such as uterine and soft-tissue LMS. Given that molecular profiling has resulted in the development of novel targeted treatment approaches for uterine and soft-tissue LMS, our study now allows the same opportunities to become available for patients with cLMS., Competing Interests: Conflicts of interest: The authors declare no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Association of Dermatologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Compromised vascular integrity facilitates the cancer cells extravasation and metastasis. However, the mechanisms leading to a disruption in vascular integrity in colorectal cancer (CRC) remain unclear. In this study, PCDH17 expression was higher in the vascular endothelial cells of colon cancer with distant metastasis, and the rates of PCDH17 + endothelial cells (ECs) was associated with the M stage in clinical pathological characteristics analysis and correlated with a poor survival prognosis. The liver and lung metastatic dissemination of MC-38 was significantly decreased in PCDH17 -/- mice. The ubiquitination and degradation of VEGFR2 was prevented by the interaction between PCDH17 and the E3 ubiquitin ligase MARCH5, which causing the separation of internalized VE-cadherin, and increased the vascular permeability and metastasis of CRC. These results highlight the importance of PCDH17 in maintaining vascular integrity, which has emphasis for endothelial barrier function in metastatic cancer. PCDH17 has the potential to be a marker for predicting tumor metastasis as well as a viable treatment target for CRC., Competing Interests: Competing interests: The authors declare no competing interests. Ethics Approval and Consent to Participate: All methods were performed in accordance with the relevant guidelines and regulations. The Ethical Committee of the Affiliated Hospital of Jining Medical University approved the animal protocols used in this study (Approval No. 2021B006). The Ethical Committee of the Affiliated Hospital of Jining Medical University approved the human protocols used in this study (Approval No. 2021B006). All CRC tissue samples were obtained with the written consent of patients. No identifiable images from human research participants are involved in this study., (© 2025. The Author(s).)

Ferroptosis, characterized by iron-dependent phospholipid peroxidation, is recognized as one of the cell death pathways activated following spinal cord injury (SCI). However, the precise regulatory mechanisms governing this process remain poorly understood. Here, this study identified TRIM32, an E3 ubiquitin ligase, as a key enhancer of neuronal ferroptosis. TRIM32 promoted neuronal ferroptosis by accelerating the degradation of GPX4, which is an essential inhibitor of ferroptosis. Conditional deletion of Trim32 in neurons markedly inhibited neuronal ferroptosis and promoted neuronal survival, eventually improving mouse locomotor functional recovery after SCI. However, overexpression of Trim32 showed aggravated neuronal loss and poor behavioral function, which could be attenuated by ferroptosis inhibitor Liproxstatin-1. Mechanistically, TRIM32 interacted with GPX4, promoted K63-linked ubiquitination modification of GPX4 at K107, thus enhanced p62-dependent autophagic degradation of GPX4. Moreover, ROS-ATM-Chk2 signaling pathway phosphorylates TRIM32 at S55, further contributing to GPX4 ubiquitination and degradation and subsequent neuronal ferroptosis after SCI, suggesting a positive feedback loop between ROS and TRIM32. Clinically, lipid peroxidation was significantly promoted in patients with SCI. These findings reveal that TRIM32 functions as a neuronal ferroptosis enhancer which is detrimental to neuronal survival and locomotor functional recovery in mice after SCI by promoting K63-linked ubiquitination and subsequent p62-dependent autophagic degradation of GPX4, suggesting a promising therapeutic target for SCI., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Influenza-related acute lung injury is a life-threatening condition primarily caused by uncontrolled replication of the influenza virus and intense proinflammatory responses. Cereblon (CRBN) is a protein known for its role in the ubiquitin-proteasome system and as a target of the drug thalidomide. However, the function of CRBN in influenza virus infection remains poorly understood. In this study, we investigated the impact of CRBN on A/Puerto Rico/8/34 (PR8) influenza virus-induced lung injury and its potential as a therapeutic target. Knocking down CRBN in vitro significantly reduces PR8-induced cell death. Using Sftpc-Cre; Crbn flox/flox lung-specific Crbn knockout mice, we demonstrated that Crbn deficiency significantly decreased mortality, weight loss, lung pathology, edema, and viral load in PR8-infected mice. PR8-infected Sftpc-Cre; Crbn flox/flox mice exhibited a marked reduction in lung inflammatory cell infiltration and suppression of MAPK pathway activation, highlighted by a significant downregulation of the MKK4-JNK-c-JUN signaling cascade. Collectively, these findings indicate that CRBN plays a pivotal role in the pathogenesis of influenza-induced lung injury by modulating MAPK pathway signaling, underscoring its therapeutic potential as a target for intervention., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Background: Enolase 1 (ENO1) is a conserved glycolytic enzyme that regulates glycolysis metabolism. However, its role beyond glycolysis in the pathophysiology of multiple myeloma (MM) remains largely elusive. Herein, this study aimed to elucidate the function of ENO1 in MM, particularly its impact on mitophagy under bortezomib-induced apoptosis., Methods: The bone marrow of clinical MM patients and healthy normal donors was used to compare the expression level of ENO1. Using online databases, we conducted an analysis to examine the correlation between ENO1 expression and both clinicopathological characteristics and patient outcomes. To investigate the biological functions of ENO1 in MM and the underlying molecular mechanisms involved, we conducted the following experiment: construction of a subcutaneous graft tumor model, co-immunoprecipitation, western blot, quantitative real-time polymerase chain reaction, immunohistochemistry, flow cytometry, and cell functional assays., Results: ENO1 was identified as an unfavorable prognostic factor in MM. ENO1 knockdown suppresses tumorigenicity and causes cell cycle arrest. Inhibition of ENO1-regulated mitophagy sensitizes tumor cells to apoptosis. ENO1 enhanced the stability of the YWHAZ protein by increasing the acetylation of lysine in YWHAZ while antagonizing its ubiquitination, which in turn promoted mitophagy. HDAC6 mediates the deacetylation of YWHAZ by deacetylating the K138 site of YWHAZ. Inhibition of HDAC6 increased YWHAZ acetylation and decreased YWHAZ ubiquitination. Furthermore, combination treatment with bortezomib and pharmaceutical agents targeting ENO1 has synergistic anti-MM effects both in vivo and in vitro., Conclusion: Our data suggest that ENO1 promotes MM tumorigenesis and progression. ENO1 activates mitophagy by promoting the stability of YWHAZ and inhibits apoptosis and thus, leads to the drug resistance. ENO1-dependent mitophagy promotes MM proliferation and suppresses the level of bortezomib-induced apoptosis. Inhibition of ENO1 may represent a potential strategy to reverse the resistance of MM to bortezomib., Competing Interests: Declarations. Ethics approval and consent to participate: This study was approved by the Institutional Review Board of the Shanghai East Hospital (animal use permission No. TJBB00223101). Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Hakai protein (CBLL1 gene) was identified as an E3 ubiquitin ligase of E-cadherin complex, inducing its ubiquitination and degradation, thus inducing epithelial-to-mesenchymal transition. Most of the knowledge about the protein was associated to its E3 ubiquitin ligase canonical role. However, important recent published research has highlighted the noncanonical role of Hakai, independent of its E3 ubiquitin ligase activity, underscoring its involvement in the N 6 -methyladenosine (m 6 A) writer complex and its impact on the methylation of RNA. The involvement of Hakai in this mRNA modification process has renewed the relevance of this protein as an important contributor in cancer. Moreover, Hakai potential as a cancer biomarker and its prognostic value in malignant disease also emphasize its untapped potential in precision medicine, which would also be discussed in detail in our review. The development of the first small-molecule inhibitor that targets its atypical substrate binding domain is a promising step that could eventually lead to patient benefit, and we would cover its discovery and ongoing efforts toward its use in clinic., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare that they have no competing interests., (© 2025. The Author(s).)

RAD18 is a conserved eukaryotic E3 ubiquitin ligase that promotes genome stability through multiple pathways. One of these is gap-filling DNA synthesis at active replication forks and in post-replicative DNA. RAD18 also regulates homologous recombination (HR) repair of DNA breaks; however, the current literature describing the contribution of RAD18 to HR in mammalian systems has not reached a consensus. To investigate this, we examined three independent RAD18 -null human cell lines. Our analyses found that loss of RAD18 in HCT116, but neither hTERT RPE-1 nor DLD1 cell lines, resulted in elevated sister chromatid exchange, gene conversion, and gene targeting, i.e., HCT116 mutants were hyper-recombinogenic (hyper-rec). Interestingly, these phenotypes were linked to RAD18's role in PCNA K164 ubiquitination, as HCT116 PCNA K164R/+ mutants were also hyper-rec, consistent with previous studies in rad18 -/- and pcna K164R avian DT40 cells. Importantly, the knockdown of UBC9 to prevent PCNA K164 SUMOylation did not affect hyper-recombination, strengthening the link between increased recombination and RAD18-catalyzed PCNA K164 ubiquitination, but not K164 SUMOylation. We propose that the hierarchy of post-replicative repair and HR, intrinsic to each cell type, dictates whether RAD18 is required for suppression of hyper-recombination and that this function is linked to PCNA K164 ubiquitination.

As a crucial post-translational modification (PTM), protein ubiquitination mediates the breakdown of particular proteins, which plays a pivotal role in a large number of biological processes including plant growth, development, and stress response. The ubiquitin-proteasome system (UPS) consists of ubiquitin (Ub), ubiquitinase, deubiquitinating enzyme (DUB), and 26S proteasome mediates more than 80% of protein degradation for protein turnover in plants. For the ubiquitinases, including ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzyme (E2), and ubiquitin ligase (E3), the FBK (F-box Kelch repeat protein) is an essential component of multi-subunit E3 ligase SCF (Skp1-Cullin 1-F-box) involved in the specific recognition of target proteins in the UPS. Many FBK genes have been identified in different plant species, which regulates plant growth and development through affecting endogenous phytohormones as well as plant tolerance to various biotic and abiotic stresses associated with changes in secondary metabolites such as phenylpropanoid, phenolic acid, flavonoid, lignin, wax, etc. The review summarizes the significance of the ubiquitination modification of protein, the role of UPS in protein degradation, and the possible function of FBK genes involved in plant growth, development, secondary metabolism, and stress response, which provides a systematic and comprehensive understanding of the mechanism of ubiquitination and potential function of FBKs in plant species.

The ubiquitin proteasome system (UPS) is implicated in protein homeostasis. One of the proteins involved in this system is HERC1 E3 ubiquitin ligase, which was associated with several processes including the normal development and neurotransmission at the neuromuscular junction (NMJ), autophagy in projection neurons, myelination of the peripheral nervous system, among others. The tambaleante (tbl) mouse model carries the spontaneous mutation Gly483Glu substitution in the HERC1 E3 protein. Using this model, we analyzed the implication of HERC1 E3 ubiquitin ligase in the activity of UPS, autophagy, and synaptic homeostasis in brain and muscle tissues. Regarding UPS, no differences were found in its activity nor in the specific gene expression in both brain and muscle tissues from tbl compared with the control littermates. Furthermore, the use of the specific UPS inhibitor (MG-132), did not alter the evoked neurotransmitter release in the levator auris longus (LAL) muscle. Interestingly, the expression of the autophagy-related gene p62 was significantly increased in the muscle of tbl compared to the control littermates. Indeed, impaired evoked neurotransmitter release was observed with the autophagy inhibitor Wortmannin. Finally, altered levels of Clathrin and Synaptophysin were detected in muscle tissues. Altogether, our findings show that HERC1 E3 ubiquitin ligase mutation found in tbl mice alters autophagy and vesicular recycling without affecting proteasomal function.

Nutrient deprivation is a major trigger of autophagy, a conserved quality control and recycling process essential for cellular and tissue homeostasis. In a high-content image-based screen of the human ubiquitome, we here identify the E3 ligase Pellino 3 (PELI3) as a crucial regulator of starvation-induced autophagy. Mechanistically, PELI3 localizes to autophagic membranes, where it interacts with the ATG8 proteins through an LC3-interacting region (LIR). This facilitates PELI3-mediated ubiquitination of ULK1, driving ULK1's subsequent proteasomal degradation. PELI3 depletion leads to an aberrant accumulation and mislocalization of ULK1 and disrupts the early steps of autophagosome formation. Genetic deletion of Peli3 in mice impairs fasting-induced autophagy in the liver and enhances starvation-induced hepatic steatosis by reducing autophagy-mediated clearance of lipid droplets. Notably, PELI3 expression is decreased in the livers of patients with metabolic dysfunction-associated steatotic liver disease (MASLD), suggesting its role in hepatic steatosis development in humans. The findings suggest that PELI3-mediated control of autophagy plays a protective role in liver health.

Mediator25 (MED25) has been ascribed as a signal-processing and -integrating center that controls jasmonate (JA)-induced and MYC2-dependent transcriptional output. A better understanding of the regulation of MED25 stability will undoubtedly advance our knowledge of the precise regulation of JA signaling-related transcriptional output. Here, we report that Arabidopsis MED16 activates JA-responsive gene expression by promoting MED25 stability. Conversely, two homologous E3 ubiquitin ligases, MED25-BINDING RING-H2 PROTEIN1 (MBR1) and MBR2, negatively regulate JA-responsive gene expression by promoting MED25 degradation. MED16 competes with MBR1&2 to bind to the von Willebrand Factor A (vWF-A) domain of MED25, thereby antagonizing the MBR1&2-mediated degradation of MED25 in vivo. In addition, we show that MED16 promotes hormone-induced interactions between MYC2 and MED25, leading to the activation of JA-responsive gene expression. Collectively, our findings reveal a multiprotein regulatory module that robustly and tightly maintains MED25 homeostasis, which determines the strength of the transcriptional output of JA signaling., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Mono-ubiquitination of lysine 18 on histone H3 (H3K18ub), catalyzed by UHRF1, is a DNMT1 docking site that facilitates replication-coupled DNA methylation maintenance. Its functions beyond this are unknown. Here, we genomically map simultaneous increases in UHRF1-dependent H3K18ub and SUV39H1/H2-dependent H3K9me3 following DNMT1 inhibition. Mechanistically, transient accumulation of hemi-methylated DNA at CpG islands facilitates UHRF1 recruitment and E3 ligase activity toward H3K18. Notably, H3K18ub enhances SUV39H1/H2 methyltransferase activity and, in colon cancer cells, nucleates new H3K9me3 domains at CpG island promoters of DNA methylation-silenced tumor suppressor genes (TSGs). Disrupting UHRF1 enzyme activity prevents H3K9me3 accumulation while promoting PRC2-dependent H3K27me3 as a tertiary layer of gene repression in these regions. By contrast, disrupting H3K18ub-dependent SUV39H1/H2 activity enhances the transcriptional activating and antiproliferative effects of DNMT1 inhibition. Collectively, these findings reveal roles for UHRF1 and H3K18ub in regulating a hierarchy of repressive histone methylation signaling and rationalize a combination strategy for epigenetic cancer therapy., Competing Interests: Declaration of interests C.J.F. and J.R.H. are paid employees of Cell Signaling Technology., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with limited treatment options and a poor prognosis. The critical role of epigenetic alterations such as changes in DNA methylation, histones modifications, and chromatin remodeling, in pancreatic tumors progression is becoming increasingly recognized. Moreover, in PDAC these aberrant epigenetic mechanisms can also limit therapy efficacy. This study aimed to investigate the expression and prognostic significance of a key epigenetic complex encompassing DNA methyltransferase-1 (DNMT1), the histone methyltransferase G9a, and the scaffold protein UHRF1 in PDAC. We also evaluated the therapeutic potential of an innovative inhibitor targeting these epigenetic effectors., Methods: Immunohistochemical analysis of DNMT1, G9a, and UHRF1 expression was conducted in human PDAC tissue samples. Staining was semi-quantitatively scored, and overexpression was defined as moderate to strong positivity. The prognostic impact was assessed by correlating protein expression with patient survival. The antitumoral effects of the dual DNMT1-G9a inhibitor CM272 were tested in PDAC cell lines, followed by transcriptomic analyses to identify underlying mechanisms. The in vivo antitumoral efficacy of CM272 was evaluated in PDAC xenograft and syngeneic mouse models, both alone and in combination with anti-PD1 immunotherapy., Results: DNMT1, G9a, and UHRF1 were significantly overexpressed in PDAC cells and stroma compared to normal pancreatic tissues. Simultaneous overexpression of the three proteins was associated with significantly reduced survival in resected PDAC patients. CM272 exhibited potent antiproliferative activity in PDAC cell lines, inducing apoptosis and altering key metabolic and cell cycle-related genes. CM272 also enhanced chemotherapy sensitivity and significantly inhibited tumor growth in vivo without detectable toxicity. Combination of CM272 with anti-PD1 therapy further improved antitumor responses and immune cell infiltration, particularly CD4 + and CD8 + T cells., Conclusions: The combined overexpression of DNMT1, G9a, and UHRF1 in PDAC is a strong predictor of poor prognosis. CM272, by targeting this epigenetic complex, shows promising therapeutic potential by inducing apoptosis, reprogramming metabolic pathways, and enhancing immune responses. The combination of CM272 with immunotherapy offers a novel, effective treatment strategy for PDAC., Competing Interests: Declarations. Ethics approval and consent to participate: The collection of PDAC patient samples was performed at two different research institutions while adhering to ethical guidelines and informed consent procedures. The study protocol was reviewed and approved by the local Ethical Committee of the University Hospital of Modena (Comitato Etico dell'Area Vasta Emilia Nord- Protocol Number: 0013043/19—Pratica 299/2019/OSS/AOUMO) and the Clinical Research Ethical Committee of Navarra (Pyto2015/120). All patients provided written informed consent. All animal procedures involving mice were performed in compliance with regulations concerning animals used in scientific research. The animal procedures in the VHIO were approved by the institution's Ethical Committee and the Catalan Regional Government., while the CIMA-University of Navarra approved the project under project approval #R-CP001-15GN. Consent for publication: All authors read this manuscript and approve for publication. Competing interests: The authors declare that they have no competing interest., (© 2025. The Author(s).)

Macrophages play important roles in maintaining intestinal homeostasis and in the pathogenesis of inflammatory bowel diseases (IBDs). However, the underlying mechanisms that govern macrophage-mediated inflammation are still largely unknown. In this study, we report that RNF128 is downregulated in proinflammatory macrophages. RNF128 deficiency leads to elevated levels of effector cytokines in vitro and accelerates the progression of IBD in mouse models. Bone marrow transplantation experiments revealed that RNF128 deficiency in bone marrow cells contributes to the worsening of DSS-induced colitis. Mechanistically, RNF128 interacts with and destabilizes S100A8 by promoting its autophagic degradation, which is mediated by the cargo receptor Tollip. Moreover, the administration of an S100A8 neutralizing antibody mitigated the development of colitis and improved survival in DSS-treated Rnf128 -/- mice. Overall, our study underscores the anti-inflammatory role of RNF128 in macrophages during the progression of colitis and highlights the potential of targeting the RNF128-Tollip-S100A8 axis to attenuate intestinal inflammation for the treatment of colitis., Competing Interests: Competing interests: The authors declare no competing interests. Ethics approval: All animal interventions were approved by the Animal Ethics Committee of The First Affiliated Hospital of Zhengzhou University, China. Human tissues used in this study was approved by the Human Ethical Committee of the First Affiliated Hospital of Zhengzhou University., (© 2025. The Author(s).)