The ongoing epidemic of mpox highlights the urgency of developing novel and effective vaccines against mpox virus (MPXV). Circular RNA (circRNA) has emerged as a promising novel vaccine platform due to its high stability, resistance to exonuclease-mediated degradation, and potential to support prolonged antigen expression. Based on our lipid nanoparticle (LNP)-encapsulated circRNA vaccine platform, we developed two novel bi-antigen circRNA vaccines cirEV and cirMV, which respectively encode the combination of MPXV extracellular enveloped virion (EEV) antigens (A35R and B6R) or intracellular mature virion (IMV) antigens (A29L and M1R). The two MPXV circRNA vaccines alone or mixed as a combination vaccine successfully induce high levels of antigen-specific antibody responses and cellular immune responses against the MPXV antigens and protect mice from lethal vaccinia virus (VACV) challenge in a dose-dependent manner. Furthermore, both circRNA vaccines can provide complete long-term cross-protection against lethal VACV challenge at day 260 after first immunization, indicating the durability of vaccine-induced protective immunity. Notably, vaccine-induced cellular immune responses play a crucial role in immune protection and virus clearance in mice. Our study provides critical insights to understand the protective mechanisms underlying circRNA vaccines in an orthopoxvirus surrogate model, demonstrating that bi-antigen circRNA vaccines represent a promising multivalent vaccine platform.

Odorant-binding proteins (OBPs) play essential roles in olfactory-mediated oviposition site selection in insects. The expression of OBPs in female Plodia interpunctella was analyzed after exposure to nonanal, and significantly upregulated OBPs were cloned, recombinantly expressed, and their binding affinities were determined. Female preference for nonanal was determined by RNA interference followed by Y-tube choice and two-choice oviposition assays. The expression levels of PintOBP11 and PintGOBP2 were significantly upregulated relative to the control. PintOBP11 was highly expressed in the head and exhibited strong binding affinity to nonanal. The expression levels of PintOBP11 and PintGOBP2 were decreased by 86.50% and 64.44% at 24 h, respectively, and female preference for nonanal was significantly decreased after simultaneous RNAi of PintOBP11 and PintGOBP2. These findings reveal the roles of PintGOBP2 and PintOBP11 in olfactory recognition underlying nonanal-mediated oviposition preference in female P. interpunctella, offering useful insights for attractant-based management of this pest.

The rabies virus (RABV) is known to have four potential receptors, including the nicotinic acetylcholine receptor (nAChR), neural cell adhesion molecule (NCAM), low-affinity nerve growth factor receptor (NGFR), and metabolic glutamate receptor 2 (mGluR2). However, the regulatory mechanism that maintains the stability of these receptors on the cell membrane remains unclear. In this study, we found that 78 kDa glucose-regulated protein (GRP78) is required for RABV infection in cells. Knockdown of GRP78 decreased the internalization of RABV. A GRP78 monoclonal antibody effectively blocked RABV infection. Mechanistically, GRP78 interacts with RABV candidate receptors directly through the 19 to 50 amino acids at the N-terminal of GRP78, which is crucial for RABV infection. GRP78 can form complexes with viral receptors and viral envelope glycoproteins on the cell membrane. Silencing GRP78 led to a decrease in the expression of RABV candidate receptors on the cell membrane. Our findings suggest that GRP78 plays a critical role in stabilizing the cell-surface expression of these receptors by directly interacting with them, which in turn facilitates the internalization of RABV. These findings provide new insights into the complex process of RABV invasion into cells and may contribute to the development of therapeutics against RABV. IMPORTANCE:Rabies virus (RABV) is a neglected but fatal zoonotic virus. Research has shown that the RABV glycoprotein binds to cell receptors and, with host factors' cooperation, invades cells to initiate its life cycle. Although several potential receptors and host factors for RABV have been identified, the process of virus invasion remains unclear. Here, we report that GRP78 has a significant inhibitory effect on RABV infection and plays a crucial role in its early stage, particularly during virus internalization. Furthermore, we found that GRP78 directly interacts with all candidate receptors of RABV, and this interaction is critical for virus internalization. Our study reveals how GRP78 mediates RABV invading cells and deepens our understanding of host-virus interaction mechanisms during RABV infection, providing a promising target for preventing and treating rabies.

Abstract Resistance to PARP inhibitors (PARPi) is a major clinical obstacle in epithelial ovarian carcinoma (EOC). Intrinsic and acquired PARPi resistance ultimately limit therapeutic efficacy and contribute to patient mortality. Despite multiple reported mechanisms of PARPi resistance, few studies have defined the contribution of the tumor microenvironment (TME) in modulating PARPi response. Here, we demonstrate that the acidic TME, commonly observed in EOC, drives a novel mechanism of PARPi resistance. In multiple in vitro and in vivo models, a physiologically low pH of 6.5 is sufficient to enhance DNA damage repair, reduce PARPi-mediated PARP trapping, and attenuate PARPi-mediated anti-tumor efficacy. Through three independent, epigenetically focused CRISPR/Cas9 screens conducted under low pH conditions, we identified p300 as a druggable target for overcoming pH-induced PARPi resistance. Mechanistically, in an unbiased functional proteomic evaluation, we identified an ERK1/2-p300-PARP1 signaling axis activated under low pH, which alleviates PARPi-induced PARP1 trapping and associated DNA damage by directly acetylating PARP1. In primary human tumors, elevated PARP1 acetylation significantly correlates with poorer overall survival and PARPi resistance. In multiple in vivo patient-derived and syngeneic EOC models, novel p300 bromodomain inhibitors, TT125-802 and IACS-16559, synergize with PARP inhibitors (olaparib or saruparib) to inhibit the growth of therapy-resistant tumors. Together, our findings establish p300 as a promising therapeutic target for overcoming acidosis-driven PARPi resistance. Citation Format: Hao Nie, Wei Zhou, Kaixin Cheng, Dajiang Guo, Liping Liao, Xu Zhang, Chen Wang, Rafal Zielinski, Janardan N. Gavade, Shruthi Sriramkumar, Yiming Fang, Shuai Wu, Hsin-Yao Tang, Andrew V. Kossenkov, Yuan Qi, Jinsong Liu, Kang Le, Dorothea C. Gruber, Michael Soth, Miriam D. Post, Anil K. Sood, Stefanie Flückiger-Mangual, Timothy A. Yap, Benjamin G. Bitler, Rugang Zhang. Low physiological pH drives P300 mediated acetylation of PARP1 and promotes PARP inhibitor resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 370.

Immune responses need to be tightly controlled to avoid excessive inflammation and prevent unwanted host damage. Here we report that germinal center kinase MST4 responded dynamically to bacterial infection and acted as a negative regulator of inflammation. We found that MST4 directly interacted with and phosphorylated the adaptor TRAF6 to prevent its oligomerization and autoubiquitination. Accordingly, MST4 did not inhibit lipopolysaccharide-induced cytokine production in Traf6(-/-) embryonic fibroblasts transfected to express a mutant form of TRAF6 that cannot be phosphorylated at positions 463 and 486 (with substitution of alanine for threonine at those positions). Upon developing septic shock, mice in which MST4 was knocked down showed exacerbated inflammation and reduced survival, whereas heterozygous deletion of Traf6 (Traf6(+/-)) alleviated such deleterious effects. Our findings reveal a mechanism by which TRAF6 is regulated and highlight a role for MST4 in limiting inflammatory responses.

Background The progression of metabolic dysfunction-associated steatohepatitis (MASH) involves chronic, irreversible inflammatory responses linked to intracellular organelle dysfunction. While endoplasmic reticulum (ER) stress and mitochondrial impairment are recognized as critical drivers, the precise molecular mechanisms governing inter-organelle communication in this disease context remain incompletely understood. Aim This study aimed to investigate the role of the ER transmembrane protein SEC62 in MASH pathogenesis. Specifically, it sought to determine whether SEC62 expression is altered in MASH, define its functional impact on disease phenotypes, and elucidate the mechanistic pathway through which it regulates mitochondrial homeostasis and inflammation. Results SEC62 was upregulated in both human and mouse MASH livers. Hepatocyte-specific SEC62 overexpression worsened hepatic steatosis, inflammation, and mitochondrial damage, whereas SEC62 knockout ameliorated these features. Mechanistically, SEC62 interacted directly with ATAD3B at the mitochondria-associated membranes (MAMs) interface, leading to the significant downregulation of ATAD3B expression. This SEC62-ATAD3B axis resulted in defective mitophagy, increased mitochondrial reactive oxygen species (ROS) production, and amplified inflammatory responses. Conclusion Our results demonstrate that SEC62 is a novel regulator of MAMs that drives MASH progression. By interacting with and suppressing ATAD3B, SEC62 disrupts mitochondrial quality control, leading to oxidative stress and inflammation. Together, these findings define a specific molecular mechanism of organelle interplay in MASH and position SEC62 as a potential therapeutic target for intervention.

Poly(ADP-ribose) polymerase inhibitors (PARPi) are a first-line treatment for epithelial ovarian cancer (EOC) patients, but the development of resistance limits long-term therapeutic efficacy. Tumor acidosis is a hallmark of the tumor microenvironment that has been shown to promote resistance to cancer therapies, suggesting that it may impact PARPi response. Here, we demonstrated that the acidic tumor microenvironment drives a p300-dependent mechanism of PARPi resistance in EOC. Pathologically acidic pH enhanced DNA damage repair, reduced PARPi-induced PARP1 trapping, and attenuated the anti-tumor efficacy of PARPi. A CRISPR-Cas9 screen identified p300 as a druggable mediator of acidosis-induced PARPi resistance. Mechanistically, acidic pH activated an ERK-p300-PARP1 signaling axis that acetylated PARP1 at lysine 505 (PARP1 K505Ac), thereby alleviating PARPi-mediated PARP1 trapping and DNA damage. Elevated PARP1 K505Ac was associated with clinical resistance to PARPi and poor overall survival. In patient-derived and syngeneic EOC models, pharmacologic inhibition of p300 synergized with PARPi to suppress tumor growth. Together, these findings identify p300 as a key mediator of acidosis-induced PARPi resistance and a promising therapeutic target to enhance PARPi efficacy.

ARID1A knockout increases intracellular alanine in OVCAR429 cells.

Ferroptosis is an iron-dependent form of programmed cell death, which is characterized by iron overload and accumulation of lipid peroxidation. As a newly identified type of cell death, its involvement in poxvirus infection and pathogenesis remains unclear. Since MPXV shares biological and pathogenic similarities with other poxviruses, such as vaccinia virus (VACV), we used VACV-infected cell and mouse models to demonstrate that VACV infection induces ferroptosis both in vitro and in vivo. Inhibition of ferroptosis significantly reduce virus replication and alleviates the inflammatory response. Additionally, we observed that VACV infection upregulates prostaglandin-endoperoxide synthase 2 (PTGS2), which contributes to virus-triggered ferroptosis and inflammation. This study identifies a novel form of cell death triggered by poxvirus infection, shedding light on host-pathogen interactions and offering a potential therapeutic target for MPXV and other Orthopoxviruses.

Subunits of the SWI/SNF chromatin remodeling complex are altered in ∼20% of human cancers. Exemplifying the alterations is the ARID1A mutation that occurs in ∼50% of ovarian clear-cell carcinoma (OCCC), a disease with limited therapeutic options. In this study, we showed that ARID1A mutations create a dependence on alanine by regulating alanine transporters to increase intracellular alanine levels. ARID1A directly repressed the alanine importer SLC38A2 and simultaneously promoted the alanine exporter SLC7A8. ARID1A inactivation increased alanine utilization predominantly in protein synthesis and passively through the tricarboxylic acid cycle. Indeed, ARID1A-mutant OCCCs were hypersensitive to the inhibition of SLC38A2. In addition, SLC38A2 inhibition enhanced chimeric antigen receptor T-cell assault in vitro and synergized with immune checkpoint blockade using an anti-PD-L1 antibody in a genetically engineered mouse model of OCCC driven by conditional Arid1a inactivation in a CD8+ T-cell-dependent manner. These findings suggest that targeting alanine transport alone or in combination with immunotherapy may represent an effective therapeutic strategy for ARID1A-mutant cancers. SIGNIFICANCE:ARID1A mutations regulate expression of alanine transporters to control alanine distribution between cancer cells and the associated tumor microenvironment, which may be exploited therapeutically alone or in combination with immunotherapy.

Inactivation of the SWI/SNF complex sensitizes cells to SLC38A2 inhibition and SLC7A8 overexpression.

SLC38A2 and SLC7A8 are direct target genes of the SWI/SNF complex.

SLC38A2 inhibition reduces the marker of cell proliferation in ARID1A-inactivated OCCCs.

ARID1A does not create a dependence on GPTs.

Aberrant glycosylation is a crucial strategy employed by cancer cells to evade cellular immunity. However, it's unclear whether homologous recombination (HR) status-dependent glycosylation can be therapeutically explored. Here, we show that the inhibition of branched N-glycans sensitizes HR-proficient, but not HR-deficient, epithelial ovarian cancers (EOCs) to immune checkpoint blockade (ICB). In contrast to fucosylation whose inhibition sensitizes EOCs to anti-PD-L1 immunotherapy regardless of HR-status, we observe an enrichment of branched N-glycans on HR-proficient compared to HR-deficient EOCs. Mechanistically, BRCA1/2 transcriptionally promotes the expression of MGAT5, the enzyme responsible for catalyzing branched N-glycans. The branched N-glycans on HR-proficient tumors augment their resistance to anti-PD-L1 by enhancing its binding with PD-1 on CD8+ T cells. In orthotopic, syngeneic EOC models in female mice, inhibiting branched N-glycans using 2-Deoxy-D-glucose sensitizes HR-proficient, but not HR-deficient EOCs, to anti-PD-L1. These findings indicate branched N-glycans as promising therapeutic targets whose inhibition sensitizes HR-proficient EOCs to ICB by overcoming immune evasion.

METTL3 is the catalytic subunit of the methyltransferase complex, which mediates m6A modification to regulate gene expression. In addition, METTL3 regulates transcription in an enzymatic activity-independent manner by driving changes in high-order chromatin structure. However, how these functions of the methyltransferase complex are coordinated remains unknown. Here we show that the methyltransferase complex coordinates its enzymatic activity-dependent and independent functions to regulate cellular senescence, a state of stable cell growth arrest. Specifically, METTL3-mediated chromatin loops induce Hexokinase 2 expression through the three-dimensional chromatin organization during senescence. Elevated Hexokinase 2 expression subsequently promotes liquid-liquid phase separation, manifesting as stress granule phase separation, by driving metabolic reprogramming. This correlates with an impairment of translation of cell-cycle related mRNAs harboring polymethylated m6A sites. In summary, our results report a coordination of m6A-dependent and -independent function of the methyltransferase complex in regulating senescence through phase separation driven by metabolic reprogramming. Here, the authors report that METTL3 orchestrates cellular senescence by coordinating its enzymatic activity-dependent and independent functions. METTL3-mediated chromatin loops induce phase separation via metabolic reprogramming.

Objective: Calcium signaling pathways are closely related to breast cancer, including Calcium ions (Ca2+) metabolic disorders associated with cell proliferation and migration of triple-negative breast cancer (TNBC). The key proteins of store-operated Ca2+ entry (SOCE), Stromal interaction molecule 1 (Stim1) and calcium release-activated calcium channel protein1(Orai1), play critical roles in the development of TNBC. Method: Fifty cases of TNBC patients who had treatment in our hospital between January 2011 and January 2016 were included in the study, including no lymph node (LN) metastasis(N=20), 1-3 LNs metastasis(N=20) and ≥4 LNs metastasis(N=10). The para-cancerous tissues of TNBC patients and the plasma of healthy patients (N=20) were used as control groups for tumor tissue and plasma samples of TNBC patients, respectively. Real-time reverse transcription polymerase chain reaction (RT-qPCR) and immunohistochemical (IHC) were used to detect Stim1, Orai1 in the aforementioned tissue and plasma samples, respectively. Meantime, we used the Kaplan Meier (K-M) method to analyze the relationship between the expression levels of Stim1 and Orai1 and the prognosis of TNBC patients. Finally, the expression of SOCE and its key proteins (Stim1 and Orai1) in TNBC patients was analyzed using the TCGA database. Main results: In TNBC patients, the expression of Stim1 and Orai1 were higher than in the control group (P>0.05). Besides, TNBC patients without LN metastases had higher Orai1 gene expression levels than the group with LN metastasis (P<0.05). The prognosis of TNBC patients is worse when the Orai1 expression is lower (P>0.05). Furthermore, TNBC patients with a tumor diameter≥5cm have a higher degree of axillary LN metastasis and poorer prognosis compared to patients with a diameter＜5cm. On the contrary, bioinformatics analysis showed that the key protein Stim1 of SOCE was downregulated in TNBC patients and negatively correlated with the degree of lymph node metastasis, which is a protective factor in TNBC patients. Conclusion: Orai1 is expected to be tumor markers in the field of TNBC. In addition, the Orai1 expression level and tumor diameter could be used to predict the TNBC axillary LN metastatic status and prognostic level. The relationship between Stim1 and the degree of TNBC lymph node metastasis needs further research.

Abstract Background Toxoplasma gondii is an obligate protozoan parasite capable of infecting a wide range of warm-blooded animals and humans. Current treatment options, primarily pyrimethamine and sulfadiazine, have limitations, such as high recurrence rates, long treatment durations, and limited effectiveness against T. gondii. There is an unmet need for novel, safe, low-toxicity, and highly effective treatments. This study aimed to evaluate the anti-T. gondii effects of glabridin, a natural compound derived from the roots of a widely used medicinal plant. Methods The cytotoxicity of glabridin in Vero cells was assessed using a CCK-8 cell viability assay. Quantitative polymerase chain reaction (qPCR) targeting the Tg-529 gene was developed to quantify T. gondii and assess the inhibitory effects of glabridin on parasite proliferation. Ultrastructural changes in T. gondii after treatment were examined using electron microscopy. The levels of reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) were examined to assess the effects of glabridin on ROS levels and ΔΨm in T. gondii tachyzoites. Additionally, metabolomics and transcriptomics analyses were conducted to investigate the mechanisms underlying glabridin’s anti-T. gondii effects. Results Glabridin exhibited low toxicity to host cells and effectively inhibited T. gondii invasion and proliferation in vitro in a time-dependent manner. Glabridin-treated tachyzoites exhibited significant structural alterations, along with increased ROS production and a reduction in ΔΨm. Metabolomic analysis indicated that glabridin significantly affected amino acid metabolism pathways in T. gondii. In vivo, glabridin treatment significantly improved survival rates in T. gondii-infected BALB/c mice at a dosage of 100 mg/kg. Conclusions This study demonstrates that glabridin has potent anti-T. gondii effects in vitro and in vivo, likely through disruption of amino acid metabolism in the parasite. These findings highlight glabridin’s potential as a promising therapeutic agent for toxoplasmosis. Graphical abstract

Table S2 shows that original data on TMA staining.