Cell Death & Disease

Fibroblast growth factor 2 (FGF2) is frequently induced during ischemic retinal injury and has traditionally been considered a pro-angiogenic factor based largely on studies using exogenous FGF2 administration. However, its endogenous cellular origin and physiological role remain incompletely understood. Here, we used single-cell transcriptomic analysis combined with spatial validation and rod photoreceptor-specific genetic approaches to define the endogenous role of FGF2 during oxygen-induced retinopathy (OIR). We identify rod photoreceptors as a major cellular source of ischemia-induced FGF2. Notably, Fgf2 expression remained elevated during the regression of pathological neovascularization, revealing a temporal dissociation between neuronal stress responses and vascular remodeling. Single-cell analysis further showed that Fgf2 induction occurred within a coordinated photoreceptor stress-response program involving endothelin 2 (Edn2) and B-cell lymphoma 3 (Bcl3). This transcriptional signature was independently reproduced in the N-methyl-N-nitrosourea (MNU)-induced photoreceptor degeneration model. Rod-specific deletion of Fgf2 markedly increased photoreceptor apoptosis, indicating that endogenous FGF2 contributes to photoreceptor survival under ischemic stress. In contrast, neither genetic depletion nor overexpression of FGF2 altered pathological neovascularization or vaso-obliteration. Bidirectional manipulation of FGF2 further modulated the expression of representative stress-associated genes Edn2 and Bcl3, supporting FGF2 involvement in this injury-response program. Finally, receptor expression analysis revealed relatively limited endothelial expression of Fgfr1-Fgfr4 compared with VEGF receptors, suggesting a cellular basis for the distinct effects of endogenous FGF2 and VEGF signaling. Together, these findings identify endogenous retinal FGF2 as a photoreceptor-derived survival factor that is induced during stress but is insufficient to drive pathological angiogenesis. These results support a model in which neuronal adaptation and vascular remodeling represent partially distinct responses during ischemic retinal injury.

Orthodontic tooth movement relies on a tightly regulated pro-inflammatory and pro resorptive mechanoresponse of local periodontal ligament fibroblasts (PdLFs). Dysregulation is linked to complications such as root resorption and tooth loss. Hyperlipidemic conditions promote excessive PdL mechanoresponses, with growth differentiation factor 15 (GDF15) acting as potential regulator. This study examined the contribution of the inflammasome/pyroptosis pathway as underlying mechanism for dysregulated mechanoresponses. Human PdLFs were treated with palmitic acid (PA) or oleic acid (OA) for six days before 24 hours of compressive loading. PA increased CASP1, CASP4, and CASP3 activity, secretion of IL-1{beta}, IL-18, and HMGB1, and LDH release. Pharmacological blockade and siRNA-mediated knockdown of inflammasome- and pyroptosis-related targets revealed that NLRP3, CASP1, CASP4, and GSDMD partially contributed to monocyte and osteoclast overactivation. Silencing PA-increased GDF15, partially normalized the phenotype, at least in part by inflammasome/pyroptosis regulation. GDF15 acted through extracellular, and a nuclear signaling route, each accounting partially to this phenotype. Together, GDF15 partially regulates the PA-induced, pyroptosis-associated overactivated mechanoresponse alongside pyroptosis-independent mechanisms suggesting it as an interesting target for potential clinical interventions.

Mitochondrial plasticity, characterized by the dynamic balance between glycolysis and oxidative phos-phorylation in response to genetic and microenvironmental changes, is a hallmark of melanoma progression. Sphingolipids play a significant role in various aspects of cancer cell biology, including metabolic reprogramming. Previous observations had shown that the lysosomal sphingolipid-metabolizing enzyme {beta}-galactosylceramidase (GALC) rewires the lipid profile of mouse melanoma cells, exerting pro-oncogenic functions, gene silencing leading to a decreased oncogenic activity in murine and human melanoma cells. Here, we have focused on the mitochondrial sphingolipid composition and energetic metabolism in GALC knockout (KO) A2058 human melanoma cells. Targeted analysis of the mitochondrial sphingolipid profile, transcriptomic data, and mitochondrial structural and functional studies indicate that GALC loss drives a sphingolipid-mediated reprogramming of mitochondrial metabolism in absence of major structural alterations, characterized by bioenergetic insufficiency possibly due to ceramide- and sphingomyelin-driven impairment of respiratory chain function. Overall, these data indicate that GALC KO leads to a sphin-golipid-driven mitochondrial metabolic suppression and may provide novel information for the development of efficacious approaches in mitochondrial targeting melanoma therapies.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy characterized by high metastatic dissemination, therapy resistance, and poor clinical outcome. Inhibitor of differentiation 1 or ID1, is frequently overexpressed in PDAC and is associated with tumour progression and adverse clinical outcome. However, the mechanisms governing its post-transcriptional regulation remain insufficiently characterized. Here, we identify tumour-suppressive miR-615-5p as a regulator of ID1 expression in PDAC. Integrative in-silico target prediction prioritized miR-615-5p based on seed complementarity and thermodynamic stability with the ID1 3' -UTR. Expression analysis of available PDAC clinical datasets revealed reduced miR-615-5p expression associated with increased ID1 expression. Direct association was validated using luciferase reporter assays, where miR-615-5p suppressed 3' -UTR reporter activity of ID1 in a sequence dependent manner, while mutation of the predicted binding site attenuated this effect. Further biotinylated-RIP and AGO2-RIP assays demonstrated the co-enrichment of ID1 transcripts and miR-615-5p with AGO2 associated RISC complexes, while AntimiR mediated inhibition of miR-615-5p perturbs association between miR/ID1 to AGO2, supporting interaction specificity. Functionally, modulation of miR-615-5p altered ID1 expression and impacted PDAC cell migration in vitro. Mechanistic analyses further indicated that the miR-615-5p/ID1 axis influences autophagic flux where miR-615-5p mediated inhibition of autophagy suppresses ID1 dependent cellular migration. Collectively, these findings define a previously uncharacterized miRNA-dependent regulation of ID1 expression and link this axis to autophagy-associated migratory responses in PDAC cells. The study expands the post-transcriptional regulatory landscape of ID1 and provides a possible mechanism where suppression of miR-615-5p leads to ID1 overexpression and subsequent poor clinical outcome in PDAC cells.

BRCA2-mutated epithelial ovarian cancer (EOC) is deficient in homologous recombination (HR) repair and hypersensitive to PARP inhibitors. However, BRCA2-mutated EOC frequently develops PARP inhibitor resistance and the underlying mechanisms involving apoptosis evasion remain poorly understood. In this study, our bioinformatic analysis of clinical transcriptomic datasets revealed that increased expression of KLF4, a zinc finger transcription factor, was strongly associated with high-grade serous EOC subtype and reduced overall survival of patients. Using isogenic EOC cells, we demonstrated that BRCA2 mutation led to pronounced KLF4 up-regulation by PARP inhibition in an ATM-dependent manner. Silencing of KLF4 and its target gene NR4A1 enhanced olaparib-induced apoptosis. Inhibition of anti-apoptotic effectors using the BH3-mimetic navitoclax, but not the SMAC-mimetic birinapant, selectively sensitized BRCA2-mutated EOC cells to olaparib. Furthermore, KLF4 silencing abrogated olaparib-induced BCL-w and BCL-xL, while olaparib-induced cIAP2 was attenuated only by NR4A1 silencing in BRCA2-mutated EOC cells. In vivo, combined treatment of navitoclax and olaparib synergized to impede the progression of BRCA2-mutated EOC xenografts and prolong mouse survival time. Collectively, our investigations discovered KLF4 as a regulatory hub of DNA damage response and apoptosis evasion in BRCA2-mutated EOC. These findings support targeting KLF4-driven anti-apoptotic pathways as a rational strategy to overcome PARP inhibitor resistance.

Leptin receptor (LEPR) signaling has been implicated in multiple malignancies; however, its role in gastric tumors remains poorly defined. We previously demonstrated that mice with gastrointestinal epithelial cell-specific deletion of suppressor of cytokine signaling 3 (SOCS3 cKO), a negative feedback regulator of LEPR signaling, develop gastric tumors due to aberrant leptin production and LEPR activation. Here, we demonstrate that concurrent deletion of both Socs3 and Lepr (double knockout; DKO) under the same promoter substantially suppresses gastric tumorigenesis and markedly prolonged survival. Whereas SOCS3 cKO mice exhibited early stromal activation, increased TGF-{beta}1 production, accumulation of cancer-associated fibroblasts (CAFs) and collagen deposition, these tumor-promoting alterations were substantially attenuated in DKO mice. Additionally, DKO mice showed reduced inflammatory cytokine and chemokine signaling, decreased the accumulation of Gr-1+CD11b+ myeloid-derived suppressor cells, and reduced LEPR and TGF-{beta} signaling. Analysis of The Cancer Genome Atlas stomach adenocarcinoma cohort revealed high LEPR expression in the chromosomal instability and genomically stable subtypes, correlating with poor prognosis. Moreover, LEPR expression was mutually exclusive with CLDN18 and ERBB2, two major therapeutic biomarkers, and positively correlated with a CAF-related transcriptional signature. Our findings identify LEPR signaling in epithelial cells as a key driver of gastric tumorigenesis through promotion of stromal activation and tumor microenvironment development. They further highlight LEPR as a promising therapeutic target for patients with gastric cancer who are unlikely to benefit from current ERBB2/HER2- or CLDN18-directed therapies.

MLLT1 (also named ENL) is a chromatin reader protein whose encoding gene was originally identified as a chromosomal translocation partner with MLL(KMT2A) in acute leukemia. However, its role in normal hematopoiesis has not been investigated. This study uncovers a critical role of Mllt1 in normal B cell lymphopoiesis. We found Mllt1 to be essential for early B lymphocyte development using a conditional Mllt1 knockout mouse model that we developed. A significant decrease of bone marrow B-lineage progenitors, splenic transitional B cells and peripheral blood B cells were observed in Mllt1del mice compared to control Mllt1fl/fl mice. Similarly, Mllt1 deletion in in vitro cultured B-enriched progenitor cells from Mllt1fl/fl; Rosa26CreERT2/+ mice resulted in reduced B cells, demonstrating the cell-intrinsic role of Mllt1 in this process. Direct MLLT1 target genes including Il7r and critical B-lineage transcription factors, Ebf1 and Pax5, were decreased following Mllt1 deletion. Gene set enrichment, gene ontology, and functional analyses of Mllt1-deficient cells showed significant alterations related to B cell development, critical relevant signaling pathways, DNA replication, and mitochondrial function. In vitro complementation with MLLT1 rescued the B cell phenotype observed with endogenous Mllt1 deletion; however, specific MLLT1 YEATS domain mutants lacking chromatin reader and RNA-binding functions were unable to rescue the phenotype. Taken together, our research demonstrates a previously unappreciated role for MLLT1 as critical for maintenance of B cell lymphopoiesis.

Understanding the molecular vulnerabilities associated with Fanconi anemia (FA) is essential for identifying therapeutic opportunities and elucidating the mechanisms underlying disease progression and cancer predisposition. However, progress in this area remains constrained by limited availability of representative FA cellular models. To address this challenge, we defined an FA-like cellular state by identifying cancer cell lines exhibiting high-dependency on core FA pathway genes, and integrated CRISPR-Cas9 gene essentiality data at multiple molecular layers, including mutation, copy number alterations, mRNA expression, and independent patient-derived transcriptomic datasets. Functional enrichment analyses highlighted biological pathways previously implicated in FA pathogenesis, most notably aldehyde detoxification, cholesterol/fatty acid metabolism, and androgen signaling. Analysis of LINCS-L1000 perturbational transcriptomics resource identified compounds, capable of reversing the FA-associated transcriptional signature, further supporting the pharmacological tractability of the identified molecular vulnerabilities. In addition, drug-target affinity analysis prioritized aldehyde-metabolizing enzymes, including ALDH1A1 and ALDH2, as potentially druggable candidates. Notably, disulfiram demonstrated predicted high-affinity interactions with multiple proteins involved in aldehyde and lipid metabolism, including ALDH1A1, ALDH2, and MGLL, supporting its potential for further investigation in FA-related settings. Although additional validations are required, the identified vulnerabilities and candidate targets provide a foundation for future mechanistic and therapeutic investigations in FA and FA-associated malignancies.

Abstract Background: The stem cell factor receptor or c-Kit is a type III receptor tyrosine kinase, activated by its ligand Stem cell factor (SCF). Up on activation, c-kit induces signaling pathways that regulates blood cell proliferation, survival, differentiation, and migration. Several studies reported that c-Kit/SCF signaling, contributes to the development and progression of acute myeloid leukemia (AML) in patients. However, the downstream proteins regulated by c-kit activation and their clinical significance in AML remain poorly explored. Methods: Human Acute megakaryoblastic leukemia (Mo7e) cells, were-stimulated with SCF and global protein expression were profiled using two-dimensional gel electrophoresis coupled with MALDI-TOF and LC-MS/MS. Differentially expressed proteins were functionally characterized and validated using patient data from the TCGA-LAML and matched normal data from GTEx, GEO datasets, and quantitative RT-PCR. Their diagnostic and prognostic significance was assessed using ROC, Cox regression, LASSO, Kaplan Meier survival analyses, and a prognostic nomogram model. Results: Proteomic profiling identified 14 differentially expressed proteins in SCF-stimulated Mo7e cells, which are predicted to involved in cytoskeletal organization, protein folding, metabolism, vesicular trafficking, and translational regulation. Transcriptomic analysis of the TCGA-LAML cohort revealed significant dysregulation of CFL1, CCT8, HSP90B1, MDH2, EIF5A, GSN, and TPI1. Integrated ROC, Cox regression, and LASSO analyses identified CFL1, CCT8, and GSN as the most robust prognostic biomarkers associated with poor overall survival in LAML patients. Their expression patterns were validated in independent GEO datasets and by qRT-PCR in SCF stimulated Mo7e cells. Finally, a three-gene nomogram model was developed and validated to predict the overall survival probability of AML patients at 1-, 3-, and 5-year time points. Conclusions: This study identifies CFL1, CCT8, and GSN as key downstream effectors of c-Kit signaling as prognostic biomarkers for AML. These findings provide mechanistic insights into c-Kit-driven leukemogenesis and establish a clinically relevant three-gene signature for AML risk stratification and potential therapeutic targeting.

BackgroundT-cell acute lymphoblastic leukemia (T-ALL) and peripheral T-cell lymphoma (PTCL) are aggressive hematological malignancies requiring novel therapeutic strategies. The majority of T-ALL and PTCL tumors display metabolic activation and addiction to endogenous serine/glycine synthesis (SSP), providing opportunities for targeted therapy with the clinically used antidepressant sertraline, inhibiting SSP enzymes SHMT1/2. However, sertraline monotherapy only induces cell cycle arrest and has limited efficacy in suppressing disease progression in vivo. MethodsDrug synergy of sertraline combined with clinically used proteasome inhibitors carfilzomib and bortezomib was evaluated. Drug effects on cell cycle, proliferation and apoptosis were assessed in T-ALL, PTCL and healthy blood cells using flow cytometry assays. Proteomic, lipidomic and metabolic analyses on drug treated T-ALL cells were performed to elucidate the molecular mechanisms underlying drug synergy, followed by validation of changes of interest, metabolic rescues and shRNA-knockdown of SSP enzymes in T-ALL cells. In vivo therapeutic efficacy and immune remodelling were evaluated in an immunocompetent MYCN-overexpressing PTCL mouse model. ResultsSertraline acted synergistically with clinically used proteasome inhibitor carfilzomib to induce cell cycle arrest and apoptosis in T-ALL and PTCL cells with SSP activity, with minimal effects on SSP-inactive T-ALL cells or healthy blood cells. Adding carfilzomib also enhanced the therapeutic efficacy of sertraline in an aggressive MYCN PTCL model. Sertraline rewired cell metabolism towards increased cholesterol uptake and biosynthesis in SSP-active T-ALL cells, and this effect was not obtained by other means of SSP inhibition. In contrast to sertraline, carfilzomib promoted cholesterol efflux. Moreover, carfilzomib reduced total lipid levels, further restricting nutrients in sertraline - carfilzomib treated cells. Additionally, the drug combination impaired mitochondrial respiration and elevated reactive oxygen species (ROS) levels and DNA damage in SSP-active tumor cells, which was rescued by citrate supplementation. Interestingly, these metabolic changes were associated with microenvironmental changes in our mouse model, where the drug combination elevated natural killer T-cells, neutrophils and eosinophils. ConclusionsOur study identifies synergy of sertraline - carfilzomib combination treatment mediated through metabolic impairment and is associated with remodelling of the immune microenvironment. This invites for further clinical investigation of this drug combination as a therapeutic strategy for SSP-active T-cell malignancies.

Marfan syndrome (MFS) is an inherited connective tissue disorder caused by pathogenic variants in FBN1, encoding fibrillin-1, with life-threatening aortic complications arising in part from endothelial cell (EC) dysfunction. To study this in a human model, we generated hiPSC-derived ECs from three MFS patients (iMFS-ECs). We show that iMFS-ECs recapitulate known disease phenotypes, including impaired alignment in the direction of flow. Moreover, we found that iMFS-ECs do not recover from TNF--induced loss of barrier integrity, due to sustained EC contractility. iMFS-ECs exhibited TNF--induced ICAM1 upregulation and NF-{kappa}B activation comparable to healthy donor-derived hiPSC-ECs by bulk RNA-seq, while expression of genes linked to cytoskeletal arrangements, cell signaling and ECM remodeling were dysregulated. In conclusion, we show that hiPSC derived ECs can serve as a model to investigate MFS pathology. These findings establish a human iPSC platform for MFS endothelial research and suggest impaired inflammatory resolution as a novel therapeutic target.

Keratinocyte proliferation and differentiation are essential to produce the stratified structure of the epidermis and maintain its barrier function. These processes are regulated by complex mechanisms including epigenetic regulation. In this study, we evaluated the role of HDAC4/5, two class IIa histone deacetylases, in the epigenetic regulation of proliferative and differentiated human keratinocytes using dedicated 2D and 3D in vitro models. Our findings demonstrate that chemical inhibition or shRNA-mediated knock-down of HDAC4 impair keratinocyte proliferation notably through increased H3K27 acetylation and subsequent transcriptional activation of the cell cycle inhibitor gene BTG2. Interestingly, HDAC4/5 inhibition alters H3K27 acetylation landscape in proliferating keratinocytes, whereas the epigenetic identity of differentiated keratinocytes is much less affected. Inhibiting HDAC4/5 in 3D epidermis models resulted in reduced epidermal thickness and impaired barrier function linked to alteration in the lipid composition of the stratum corneum. Furthermore, analysis of several well-established skin aging markers revealed that reconstructed human epidermis treated with the HDAC4/5 inhibitor exhibit molecular and functional characteristics consistent with an aged-epidermis. Collectively, our results demonstrate that HDAC4/5 are essential for maintaining epidermal homeostasis and pave the way for the development of innovative models of skin aging based on the modulation of histone acetylation.

The Hippo pathway effector YAP1 is a potent oncogenic driver in triple-negative breast cancer (TNBC) and its activity is restrained by the scaffold protein Angiomotin-p130 (AMOT). AMOT is itself short-lived, being targeted for proteasomal degradation by NEDD4-family E3 ubiquitin ligases that dock at its L/P-PxY motifs. Here we identify Profilin1 (PFN1), an actin-binding protein with established actin-independent tumour-suppressive signalling functions in TNBC as a direct binding partner and stabilizer of AMOT. PFN1 and AMOT are co-immunoprecipitated, they share 70 common interactors and NEDD4 is one of them. Protein-protein docking shows the interaction of PFN1 on the first PPxY motif of AMOT, through its actin-binding domain. We further show that PFN1s binding leaves the AMOT LPTY motif and both coiled-coil domains entirely unoccupied. Site-directed mutagenesis of AMOT PPxY motifs shows that PFN1 binding is unaffected by substitution of the PPxY tyrosines Y242 and Y287, either alone or in combination, indicating that PFN1 engages through its actin-binding domain. Functionally, PFN1 stabilizes AMOT as shown by cycloheximide-chase assay in TNBC. PFN1 induction increases cytoplasmic retention of YAP1, reduces TEAD occupancy at the CTGF promoter and thereby suppresses TNBC cell migration. Thus, this study suggests that PFN1 deregulates tumour cells migration by interacting with AMOT through its actin-binding domain, stabilizing AMOT and thereby arresting YAP in the cytoplasm, which might be an important therapeutic target to regulate TNBC.

Polyaneuploid giant cells (PGCC), which occur more frequently in TP53-mutant tumors, are recognized as a driver of tumor recurrence and therapy resistance, but the mechanisms supporting their survival remain largely unknown. Our results indicate that polyaneuploid transition and subsequent PGCC maturation in drug-resistant phenotypes are associated with redox rewiring that shifts cellular homeostasis into mild pro-oxidative condition. These are accompanied by increased transcription of genes involved in protection against elevated reactive oxygen species and glutathione-dependent xenobiotic detoxification such as TXN, PRDX2/5, GPX1, and GSTP1/GSTO1. Functional studies provided evidence on the crucial role of Txn-Txnrd1 system in maintaining PGCC viability and their adaptation to increased level of reactive oxygen species. Pharmacological targeting of Txn or Txnrd1 as well as their silencing caused a decline in thiol content followed by further redox imbalance, which led to massive death of PGCC. Analysis of clinical datasets revealed direct and relatively strong link between transcription of TP53 and TXN or TXNRD1. Tumors with TP53low/TXNhigh or TP53low/TXNRD1high were associated with considerably poorer patient outcome, whereas elevated transcription of both TXN and TXNRD1 predicted reduced response to chemotherapy in glioblastoma and intestinal cancer. Concluding, Txn-Txnrd1 system enables PGCCs to tolerate pro-oxidative condition, thereby creating a therapeutically exploitable redox vulnerability of these cells, where Txnrd1 emerges as a potential target candidate to overcome PGCC-driven chemoresistance.

Colorectal cancer remains among the most lethal malignancies worldwide, and the proliferative programme that sustains it has proved to be a challenging target, particularly with acceptable selectivity. Herein, we combined stage-resolved transcriptomic analysis with experimental testing in colorectal cancer cells to inquire whether small molecules, in particular melatonin, act on that programme. The comparison of stage II, III and IV colorectal tumours with normal tissue identified 410 genes upregulated at every stage as a core set, dominated by cell-cycle, spindle-assembly and chromosome-segregation functions. Twenty hub genes were extracted from the corresponding protein interaction network, thirteen of which were required for viability across 59 colorectal cancer cell lines in genome-wide CRISPR screening data. Target-set enrichment nominated E2F4, FOXM1, SIN3A and both DNA-binding subunits of NF-Y as upstream regulators. NF-YA and NF-YB were distinctive in one respect: their annotated targets include BUB1 and CCNA2 but exclude NCAPG, yielding a testable prediction. Our experimental results showed melatonin reduces SW480 viability with an IC of 2.63 mM and lowers BUB1 and CCNA2 expression in different manners of concentration-dependency, while NCAPG remains unchanged. Melatonin treatment arrests cells in G1 phase, causes a drastic fall in the cycling S-phase fraction, impairs the migration and proliferation phenotype, and rises apoptosis moderately. We also found {beta}2-microglobulin to be an unsuitable normalization reference gene for CRC research due to changes upon treatment. Selective repression of two NF-Y targets with sparing of a non-target is consistent with reduced NF-Y-dependent transcription, though occupancy and subunit-level evidence are to be established.

ZNF217 is an established oncogenic transcription factor that promotes cancer progression and therapeutic resistance; however, the mechanisms regulating ZNF217 protein abundance remain poorly understood. Here, we identify ubiquitin-specific peptidase 15 (USP15) as a critical regulator of ZNF217 stability and define a reciprocal USP15-ZNF217 signaling loop that sustains malignant phenotypes in ovarian cancer. Stable overexpression of ZNF217 in OVCA420 ovarian cancer cells enhanced proliferation, epithelial-mesenchymal transition, migration, invasion, and extracellular matrix adhesion. Notably, ZNF217 overexpression increased USP15 protein abundance without altering USP15 mRNA levels, whereas ZNF217 depletion reduced USP15 protein levels, suggesting post-transcriptional regulation. Conversely, USP15 depletion markedly reduced ZNF217 protein abundance while increasing ZNF217 mRNA levels, indicating that USP15 regulates ZNF217 predominantly at the post-transcriptional level. Proteasome inhibition restored ZNF217 protein levels following USP15 depletion, further demonstrating that USP15 promotes ZNF217 protein stability. Functionally, USP15 depletion in ZNF217-overexpressing ovarian cancer cells suppressed proliferation and multiple metastatic phenotypes, including migration, invasion, extracellular matrix adhesion, anoikis resistance, and multicellular aggregate formation. In vivo, USP15 depletion significantly reduced tumor progression and metastatic burden and prolonged survival in mice bearing ZNF217-driven ovarian tumors. Furthermore, USP15 depletion enhanced the sensitivity of ZNF217-overexpressing cells to carboplatin, paclitaxel, and doxorubicin. Collectively, these findings identify USP15 as an upstream regulator of ZNF217 protein stability and reveal a positive-feedback loop between USP15 and ZNF217 that reinforces oncogenic signaling. Targeting USP15 may therefore represent an indirect therapeutic strategy for suppressing ZNF217-driven ovarian cancer, particularly given the challenges associated with directly targeting oncogenic transcription factors.

Inositol-requiring enzyme 1a (IRE1a) is a canonical signaling factor in the unfolded protein response (UPR). In addition to this essential role (which prevents the accumulation of misfolded proteins in the endoplasmic reticulum), the endoribonuclease activity of IRE1a targets multiple mRNAs for degradation through a process called Regulated IRE1a-Dependent Decay (RIDD). The products of over 50 genes have been identified as RIDD targets; however, the biological significance of this process remains underexplored. Using publicly available datasets, we examined the fate of 27 well-characterized RIDD targets in the septal wall of heart failure patients, and in mice subject to pressure overload-induced heart failure. We show that decreased mRNA abundance from these RIDD substrate genes - an outcome consistent with RIDD induction - is commonly observed in heart failure.

Vascular cognitive impairment and dementia (VCID) is increasingly recognized as a major contributor to cognitive decline; however, the mechanisms through which vascular dysfunction drives innate immune dysregulation remain poorly understood. In this study, we explore the impact of VCID on the cerebral innate immune landscape, focusing on innate lymphoid cells (ILCs) and neutrophils, two key players in neuroinflammation and brain immune homeostasis. Using a murine model of VCID induced by bilateral common carotid artery stenosis (BCAS) with modifications in C57BL/6 mice, we investigated innate immune cell distribution, polarization, and functional profiles using flow cytometry and immunofluorescence staining. Our findings reveal a compartment-specific shift in ILC populations, with a reduction of ILC2s in the meninges and concurrent expansion in the choroid plexus, accompanied by altered cytokine production. Furthermore, VCID drove a marked shift in neutrophil polarization toward a pro-inflammatory N1-like phenotype in both the meninges and choroid plexus. Critically, immunofluorescence staining of hippocampal brain sections confirmed that activated N1-like neutrophils, characterized by elevated IL-1{beta} and MPO and reduced IL-10, infiltrate the hippocampal parenchyma in VCID, suggesting a spatially progressive innate immune response spanning from CNS border compartments to brain tissue. These results identify a novel innate immune signature in VCID, compartment-specific ILC redistribution, pro-inflammatory neutrophil polarization at CNS borders, and parenchymal neutrophil infiltration in the hippocampus, which may collectively amplify neuroinflammation and accelerate cognitive decline, identifying potential therapeutic targets for vascular-related dementia.

Syndecans are transmembrane proteoglycans that regulate angiogenesis through both their glycosaminoglycan chains and core proteins. While roles for all four mammalian syndecans in new blood vessel formation are well established, it has more recently emerged that their extracellular core proteins contain discrete bioactive regulatory sequences capable of influencing cellular processes, including angiogenesis. We previously demonstrated that the syndecan-3 (SDC3) ectodomain possesses anti-angiogenic activity independent of its heparan sulphate chains. Here, we identified and characterised a novel anti-angiogenic sequence within the SDC3 ectodomain. Using recombinant truncation mutants, endothelial migration assays and peptide mapping, we localised activity to a discrete region of the extracellular domain and subsequently defined a conserved minimal nine amino acid peptide, QM111, that retained full biological activity. QM111 inhibited endothelial cell migration and angiogenic sprouting in both rat aortic ring and mouse choroidal explant models. Intrinsic disorder analysis revealed that QM111 resides within a region of comparatively reduced disorder, consistent with other syndecan regulatory sequences. This supports the concept that syndecan ectodomains contain conserved functional modules embedded within intrinsically disordered extracellular domains. QM111 did not induce inflammatory chemokine production, exhibited no detectable cytotoxicity, and retained substantial stability in human serum and vitreous humour. Finally, QM111 displayed anti-angiogenic activity comparable to the previously described syndecan-2-derived peptide QM107, with combination treatment producing more robust inhibition of angiogenesis. These findings identify QM111 as a novel endogenous anti-angiogenic peptide and support the concept that syndecan ectodomains are reservoirs of biologically active regulatory sequences with therapeutic potential. The work further establishes syndecan-derived peptides as a promising platform for the development of next-generation anti-angiogenic therapies.

Inflammatory bowel disease (IBD) is associated with chronic intestinal inflammation and gut microbial dysbiosis, yet effective microbiome-targeted therapeutics remain limited. Here, we investigated the anti-inflammatory and microbiome-modulating activities of metabolites isolated from Garcinia brassii, an endemic species of the Australian Wet Tropics. Five compounds, including a new natural product named garcitine, were isolated and structurally characterised. In human immune cells, garcinol and garcinia biflavonoid 1 significantly suppressed lipopolysaccharide-induced production of IL-1{beta}, IL-6, and TNF without detectable cytotoxicity, while parvifoliol F selectively inhibited IL-1{beta} release. Therapeutic efficacy was further evaluated in a TNBS-induced murine colitis model, where garcinia biflavonoid 1 and parvifoliol F significantly reduced colonic inflammation and improved histopathological outcomes. 16S rRNA sequencing demonstrated that both compounds restored gut microbial homeostasis by reversing colitis-associated dysbiosis and reducing inflammation-associated microbial signatures. Functional pathway prediction further suggested suppression of pro-inflammatory microbial metabolic pathways following treatment. Together, these findings demonstrate that Garcinia-derived metabolites alleviate experimental colitis through coordinated immunomodulatory and microbiome-reprogramming mechanisms and identify garcinia biflavonoid 1 and parvifoliol F as promising candidates for microbiome-targeted IBD therapeutics.