Citations

Background Glioblastoma (GBM) remains the most aggressive primary adult brain cancer attributed to its immunosuppressive nature. Radiation therapy (RT) and concurrent temozolomide chemotherapy are the standard treatments for GBM. Emerging evidence indicates that metformin has potential as an anti-tumor agent that can reshape the immune landscape across various malignancies. We thus postulate that metformin may enhance the anti-tumor effect of RT by modulating the immunosuppressive milieu in GBM. Methods We first explore multiple in vitro conditions, with or without pre-induction, and mimicked a tumor microenvironment to demonstrate a highly context-dependent effect of metformin on the polarization of bone marrow-derived macrophages (BMDMs). We then investigated the antitumor activity and immune-modulatory effects of metformin in combination with RT in GBM-bearing mice. Results The in vitro experiment showed that metformin inhibited the immunosuppressive effects of IL-4/IL-13 but also the immunostimulatory effects of Lipopolysaccharide (LPS) on BMDMs, demonstrating bidirectional immunomodulatory properties that depend on the baseline inflammatory stimulus. In tumor cell co-culture environment, metformin exhibited context-dependent immunoregulatory effects, predominantly promoting M1-associated activation. Notably, concurrent metformin treatment counteracted M2 polarization typically induced by the tumor microenvironment. In a high m-MCSF inducted M2-dominated condition, metformin preferentially shifted the highly polarized M2 phenotype toward an M1-like state in a time and dose-dependent manner but with limited promotion of M1 subtype maturation. RNAseq results on BMDM treated with metformin showed increased homeostasis. Metformin showed dose-dependent immunomodulatory effects when combined with RT in vitro . In syngeneic GBM mouse models, concurrent metformin + RT significantly prolonged survival and reduced tumor burden by reprogramming tumor-associated macrophages (TAMs), elevating intratumoral CD8+ T-cell infiltration and the CD8+/Treg ratio, increasing circulating CD8+ T cells, reversing RT-induced expansion of monocytic myeloid-derived suppressor cells (mMDSCs), and expanding CD4+ and CD8+ effector memory populations in peripheral blood. Conclusion Metformin demonstrates inhibitory effects on M2 phenotype of macrophages. However, it is not a simple M2 inhibitor; instead, it functions primarily as a neutralizer of highly polarized macrophage states by promoting transcriptomic homeostasis. This context-dependent activity enables metformin to relieve the profoundly immunosuppressive TME of GBM to potentiate the anti-tumor effects of RT and by enhancing systemic immune memory.

Importance Elevated low-density lipoprotein cholesterol (LDL-C) is a modifiable risk factor for cardiovascular disease, the leading cause of premature death worldwide. Assessing the LDL-C–related burden is critical for guiding prevention and treatment strategies. Objectives To estimate the global, regional, and national burden of ischemic heart disease and ischemic stroke attributable to elevated LDL-C (relative to 35-54 mg/dL) from 1990 to 2023 and to quantify the contributions of population growth, aging, risk-deleted burden, and exposure changes to burden trends. Design, Setting, and Population This comparative risk assessment, part of the Global Burden of Disease Study 2023, estimated population-level LDL-C exposure and associated health loss in 204 countries and territories. Mean LDL-C levels were estimated using spatiotemporal gaussian process regression based on 806 studies across 161 countries. Relative risks were derived from meta-analyses of 38 randomized clinical trials. Population-attributable fractions for deaths and disability-adjusted life-years (DALYs) were estimated by age and sex for adults aged 25 years or older from 1990 to 2023, with 95% uncertainty intervals. Exposure Population-level LDL-C concentrations. Main Outcomes and Measures Population-attributable fractions, counts, and rates (all ages and age standardized per 100 000) of LDL-C–attributable deaths and DALYs from ischemic heart disease and ischemic stroke, with uncertainty intervals. Results In 2023, elevated LDL-C accounted for 3.6 million deaths (95% uncertainty interval, 2.2-5.4 million; 6.0% of global mortality) and 90.7 million DALYs (95% uncertainty interval, 58.9-123.3 million; 3.2% of DALYs). Although global all-ages rates remained stable, age-standardized death and DALY rates decreased by 45.6% and 39.5%, respectively, since 1990. In 2023, age-standardized LDL-C–attributable DALY rates were highest in Eastern Europe and lowest in high-income Asia-Pacific. One-third of the global LDL-C burden occurred in India and China. Population growth and aging drove the increasing burden, with notable regional disparities in LDL-C exposure and risk-deleted DALY rates shifting toward middle-sociodemographic settings. Conclusions and Relevance Despite declining age-standardized rates, the absolute LDL-C burden has increased since 1990 due to demographic changes and has shifted toward middle-sociodemographic countries. Measurement and surveillance gaps persist. Strengthened prevention, diagnosis, and treatment access strategies are essential to mitigate the health burden of LDL-C.

Abstract Introduction Microglia are the resident immune cells of the central nervous system, classically studied for neuroinflammation. A specialized subset, vessel-associated microglia (VAM), whose somata directly contact capillaries, constitutes ∼30% of microglia in the naïve brain. Only recently have VAM been recognized as regulators of brain circulation, influencing blood—brain barrier (BBB) integrity and cerebral blood flow, yet their role in pathological vascular remodeling remains unclear. To address this gap, we used glioma models in which peritumoral capillaries undergo extensive vascular remodeling and BBB dysfunction, providing an in vivo platform to probe capillary vulnerability and vascular stability. Methods We combined pharmacological microglial ablation via CSF1R inhibitors with longitudinal in vivo two-photon imaging to visualize microglia—capillary interactions. Behavioral testing, survival analysis, T2-weighted MRI, and immunostaining were performed in parallel. Results Over half of the microglia-depleted mice developed acute, lethal paralysis by 15 days, whereas control tumor-bearing mice remained asymptomatic and survived 30 days. MRI revealed large intracranial hemorrhages and severe edema, and two-photon imaging showed nodular, abnormal vasculature at paralysis onset. The peritumoral region contained dense capillary networks with a marked increase in VAMs (>60%). Genetic lineage tracing confirmed these cells were microglia, exhibiting elongated, vessel-wrapping morphology, also observed following single-vessel photothrombosis and consistent with a response to capillary injury. Conclusion Our findings identify VAMs as critical neurovascular stabilizers that preserve peritumoral capillary integrity and prevent lethal hemorrhage in glioma, highlighting an essential immune role in brain vascular homeostasis. Notably, intracranial hemorrhage has repeatedly emerged across clinical trials of CSF1R inhibitors, raising important safety considerations for CSF1R-targeted therapies in the diseased brain. Funding Source AHA postdoc fellowship (26POST1560008) (J.Z.) Topic Categories Neuroimmunology (NEUR)

Most genetic variants associated with complex traits are hypothesized to regulate gene expression. To understand the genetics underlying gene expression variability, we characterized 14,324 RNA-sequencing samples from the Trans-Omics for Precision Medicine program and performed expression and splicing quantitative trait locus (e/sQTL) analyses in six tissues and cell types, including whole blood ( n = 6454) and lung ( n = 1291). We detected tens of thousands of secondary cis-e/sQTLs, showing that secondary cis-e/sQTL discovery remains unsaturated. We fine-mapped UK Biobank–derived genome-wide association study (GWAS) signals from 164 traits and identified e/sQTL colocalizations for 10,611 GWAS signals, including 7096 that colocalize with secondary e/sQTLs. Our results suggest that even larger e/sQTL analyses will uncover additional secondary e/sQTLs, further benefiting GWAS interpretation.

Abstract Aims Heart failure (HF), a major global health challenge, affects millions worldwide and poses substantial healthcare and economic burdens. It is estimated that a large proportion of those with early systolic dysfunction remain asymptomatic at a stage when guideline-directed medical therapies have been shown to prevent disease progression. To develop an artificial intelligence (AI) model capable of predicting abnormal left ventricular ejection fraction (EF) directly from static, non-gated, non-contrast chest computed tomography (CT) scans as a form of opportunistic screening, Methods and results Using a multi-institutional dataset of 34 058 paired non- contrast CT images and echocardiogram reports from two academic centres, we trained our model of classification for predicting left-ventricle ejection fraction (LVEF) categories: abnormal EF (EF < 50%) vs. normal on 25 948 studies. We validated the model on 8110 paired chest CT and echocardiogram results from a separate institution. The model achieved an area under the receiver operating characteristic (AUROC) curve of 0.786 on the hold-out test set and 0.762 on external validation to detect an abnormal EF (<50%). Beyond strong predictive performance, the AI model surpassed expert radiologists in both accuracy and efficiency and provided interpretable visualizations highlighting imaging features linked to reduced LVEF. Conclusion In this study, we developed and validated an AI model capable of predicting abnormal LVEF directly from static, non-gated, non-contrast chest CT scans, a novel application for an imaging modality typically used for unrelated indications as a form of opportunistic screening. This technology holds significant promise for early detection of systolic HF, reducing the diagnostic gap, and improving outcomes in asymptomatic HF patients.

Abstract Glioblastoma (GBM) is the most common and lethal primary malignant brain tumor in adults, with median survival remaining approximately 12–15 months despite aggressive multimodal therapy. Therapeutic resistance and tumor recurrence are driven in part by limited drug penetration across the blood–brain barrier (BBB) and the persistence of brain cancer stem cells (BCSCs), highlighting the need for brain-penetrant therapeutic platforms capable of achieving sustained intratumoral delivery. Here, we developed a dendrimer-based nanotherapeutic by conjugating metformin to a fourth-generation hydroxyl-terminated polyamidoamine dendrimer (P4-MET) to enhance intracranial bioavailability and therapeutic efficacy in GBM. P4-MET exhibited favorable pharmacokinetic properties, including prolonged retention within the tumor microenvironment, and demonstrated enhanced cytotoxicity against GBM cell lines relative to free metformin (f-MET). Mechanistical studies with transcriptomic profiling by RNA sequencing revealed distinct treatment-associated molecular signatures, identifying BOLA2B as the most significantly differentially expressed gene between treatment groups. Specifically, BOLA2B expression was markedly elevated in f-MET–treated cells but not so following P4-MET treatment. Given the established association of BOLA2B with mTORC1 signaling and GPX4-mediated ferroptosis resistance, these findings suggest that P4-MET may, at least in part, enhance therapeutic efficacy by modulating ferroptosis-associated pathways. In orthotopic GBM models, combination treatment with P4-MET and radiotherapy (RT) significantly prolonged overall survival and increased tumor cell death compared with either monotherapy alone, consistent with a synergistic radiosensitizing effect. Importantly, P4-MET demonstrated minimal systemic toxicity, supporting its favorable therapeutic index and translational potential. Collectively, these findings establish P4-MET as a brain-penetrant nanomedicine platform that improves metformin delivery, modulates ferroptosis-related signaling networks, and potentiates radiotherapeutic response in GBM. This study highlights the potential of dendrimer-enabled metabolic nanotherapies to overcome therapeutic resistance in malignant brain tumors.

Introduction: Calibrated automated thrombogram assay parameters have been shown to assess hypercoagulation state and, therefore, may independently predict posttrauma, symptomatic venous thromboembolism (VTE). Yet, calibrated automated thrombogram lacks high throughput and standardization, limiting diagnostic potential. This study analyzed thrombin generation (TG) profiles in trauma patients using a high-throughput assay, processing up to 10 samples at once, providing batch testing capabilities. We hypothesized that trauma patients who developed VTE would show distinct TG profiles compared with those who did not. Methods: Trauma patients presenting to a Level I Trauma Center had samples collected within 12 hours postinjury prospectively. Follow-up was conducted to 90 days, time to symptomatic VTE diagnosis or death, confirmed via autopsy or imaging. TG profiles were measured from the ST Genesia assay. Data were presented as median (interquartile ranges) or n (%), with the Wilcoxon rank-sum or chi-squared test. Associations between TG parameters and clinical risk factors were assessed using Spearman correlation analysis or the Wilcoxon rank-sum test. Results: Two hundred and fifty-four trauma patients were analyzed [48.5 years (31.0, 62.0), 72.0% male]: 64 patients with VTE (25.2%) to 190 with non-VTE. VTE pts had a median time to VTE of 8 days, with 29 developing deep venous thrombosis, 24 with pulmonary embolism, and 11 with deep venous thrombosis/pulmonary embolism. No significant differences were found in age, sex, or body mass index; significantly more VTE patients underwent surgery and blood transfusions within 24 hours. TG profiles demonstrated accelerated TG in patients who developed VTE compared with non-VTE, with significant differences in peak height ( P = 0.001), time to peak ( P = 0.021), endogenous thrombin potential ( P < 0.001), and velocity index ( P = 0.001). Conclusion: TG profiles using ST Genesia can differentiate trauma patients at high risk of developing VTE. The platform suits clinical labs needing high throughput by providing batch testing capabilities. Study type: Prospective study with less than large effect and no negative criteria. Level of evidence: II.

Objective: The identification of reliable biomarkers in trauma patients (pts) remains a clinical challenge. Nucleosomes, which are DNA wrapped around histone protein cores, have been used as reliable markers for quantification in sepsis, acute respiratory distress syndrome, and lymphoma. We hypothesized that: 1) levels of circulating nucleosomes quantified after traumatic injury, specifically histone H3.1 and its citrullinated R8 posttranslation modification (H3R8 Cit), would be increased after trauma and 2) that levels of circulating nucleosomes would be further, increased in pts who went on to develop venous thromboembolism (VTE), as these nucleosomes may be clot-enhancing mediators. Methods: Trauma pts presenting to a Level I trauma center were evaluated for inclusion in a prospective case-cohort study, and citrated blood samples were collected within 12 hours of injury. Pts were followed for up to 90 days and VTE occurrence was confirmed via autopsy or imaging. Pts who developed incident, symptomatic VTE, and those who did not develop VTE were selected at a 1:3 ratio. The effect of trauma was assessed by comparison with healthy volunteer samples. Circulating nucleosomes were quantified using Nu.Q H3.1 and Nu.Q H3R8 Cit assays. Data are presented as median [interquartile range] or n (%), with Wilcoxon Rank-Sum or chi-squared test performed between trauma pts who developed symptomatic VTE versus those who did not, with a P value < 0.05 as statistically significant. Results: A total of 639 trauma pts were analyzed [51 years (33, 65), 71.0% male, 94.1% blunt, injury severity scores 17 (9, 27)]. Both H3.1 [359.7 (58.4, 1769.3) vs. 21.5 (15.3, 26.6) ng/mL, P < 0.001] and H3R8 Cit levels [209.4 (45.4, 665.5) vs. 22.3 (16.2, 28.9) ng/mL, P < 0.001] were greater in trauma pts than in 10 healthy volunteers. The 160 pts with VTE were then compared with 479 without VTE. VTE pts had a median time to VTE of 8.5 days, with 91 developing symptomatic deep venous thrombosis, 48 with pulmonary embolism, and 21 with both deep venous thrombosis and pulmonary embolism. No significant differences were found in age, sex, or mechanism between pts with or without VTE. However, VTE pts had higher injury severity scores [24 (14, 34), 14 (9, 24), P < 0.001] and body mass index [29.1 (24.3, 34.2), 27.6 (24.2, 32.0) kg/m 2 , P = 0.037]. A greater percentage of VTE pts underwent surgery requiring general anesthesia (53.1%, 34.0%, P < 0.001) and received blood transfusions within 24 hours of injury (51.9%, 24.0%, P < 0.001). H3.1 levels were significantly greater in trauma pts who developed VTE compared with those who did not [828.4 (112.0, 3186.5), vs. 276.7 (50.3, 1237.0) ng/mL, P < 0.001], as were H3R8 Cit levels [350.4 (77.4, 729.5), vs. 189.2 (40.8, 632.6) ng/mL, P = 0.005]. No differences in levels of H3.1 and H3R8 Cit were found between early (diagnosed day 0–7 after injury) and late (diagnosed > day 7) VTE. Conclusions: Levels of the H3.1 and H3R8 Cit nucleosomes are elevated early after traumatic injury, especially in those who developed VTE. These findings underscore the importance of understanding the pathophysiology of nucleosomes in inducing VTE and their role as biomarkers