Citations

Abstract Background Alzheimer's disease (AD) affects all brain cells and has complex genomic and immunological alterations. Previous research discovered missense AD risk or protective variants in microglial genes ABI3 and PLCG2 , respectively. Expression levels of these genes are altered in AD and can influence microglial function. This study aims to uncover protective, and risk microglial molecular signatures associated with these variants to determine their role in microglial subtypes and states in AD by single cell expression and functional studies. Method We generated microglia‐enriched snRNAseq data from donors harboring either AD protective PLCG2 or AD risk ABI3 missense mutations, or neither mutation. After standard snRNAseq QC, we performed differential expressed gene (DEG) analysis of all microglial cells between variant carriers and non‐carriers using MAST. We defined protective signature as genes that are both down in ABI3 and up in PLCG2 mutation‐carriers. In contrast, risk signature genes are up in ABI3 and down in PLCG2 mutation‐carriers. We investigated the conservation of protective and risk signatures across multiple datasets, including scRNAseq data from iPSC‐derived microglia cells carrying PLCG2 protective variant, snRNAseq data from AD‐resilient donors, and data from AD and other diagnostic groups across multiple brain regions sourced from external datasets. Result We obtained snRNAseq profiles of 35,000 microglia from AD variant carriers. Our DEG analysis among all microglia cells provided 227 microglial protective and 293 risk signature genes defined by these variants. Using integrated analysis of multiple internal and external datasets, we further narrowed down these signatures. We determined that these high‐confidence protective signature genes are downregulated in early AD, upregulated in late AD brains and positively‐correlated with protective variant load in in vitro models. In contrast, risk signature genes are upregulated in early AD, downregulated in late AD and resilient donors. Risk signature expression is decreased with protective PLCG2 variant load, and altered with Aβ treatment in in vitro models. Conclusion Our study uncovers microglia specific protective and risk signatures associated with AD using sn/scRNAseq datasets from multiple sources and models. These findings nominate novel immune targets and pathways with implications for microglial function in health and disease, and ultimately therapeutic potential.

Abstract Background Cerebral amyloid angiopathy (CAA), characterized by the accumulation of amyloid‐beta in the cerebrovasculature, affects blood vessel integrity leading to brain hemorrhages and an accelerated cognitive decline in Alzheimer’s Disease (AD) patients. Our previous genome‐wide association study (GWAS) identified a LINC‐PINT splice variant associated with lower CAA levels in individuals without the APOE e4 allele and higher levels of LINC‐PINT expression in the brain of AD donors. In this study, we expand our GWAS to include additional donors with AD and those lacking significant AD neuropathology (non‐AD), with available CAA scores. Method In our prior study we assessed 853 AD donors. We expanded this by addition of genetic data from 550 AD and 502 non‐AD donors from the Mayo Clinic Brain Bank, scored for CAA. We performed QC and imputation (TOPMED) of all datasets. We conducted GWAS in AD only ( N = 1,363), non‐AD only, and all donors ( N = 1,865) by testing imputed variant dosages for association with square root transformed CAA using linear regression, adjusting for relevant covariates. To assess associations in the context of major CAA risk factors, we performed interaction analysis with APOEe4 presence and sex; and pursued stratified analyses. Result Variants at the APOE locus were identified as the most significant in our study. In addition, several other variants approached genome‐wide significance after adjusting for AD neuropathology (Braak stage and Thal phase). T he LINC‐PINT splice variant remained associated with lower CAA scores in AD donors without the APOEe4 risk allele. To enhance the robustness of our findings, we are pursuing further expansion of our study cohort to include other available datasets. To explore putative functional consequences of key variants we are collecting peripheral gene expression measures in participants from Mayo Clinic with neuroimaging measures including microhemorrhages. Conclusion We expect this study will provide further insights into the genetic architecture underlying risk for CAA, both in the context of significant AD pathology, and without. Characterization of genetic variants and their functional outcomes may lead to new avenues of research aimed at identifying biomarkers and therapies to treat CAA, a common co‐pathology in those with and without AD.

Abstract BACKGROUND High grade astrocytoma with piloid features (HGAP) is a newly recognized tumor with a distinct DNA methylation profile. Its clinical course, treatment response, and outcomes remain poorly understood. METHODS We conducted a retrospective cohort study across three Mayo Clinic sites including adults with a HGAP diagnosis confirmed by DNA methylation profiling. RESULTS 17 patients were included (median age 38 years, Q1, Q3: 29–59; 9 male). DNA methylation-based tumor classification using the NCI/Bethesda classifier (v2) indicated a match to HGAP with high confidence (calibrated score >0.9) in 14 cases and was suggestive in 3 cases. All had MAPK pathway alterations (NF-1 mutation in 11, FGFR1 mutation in 2, KIAA1549::BRAF fusion in 2, FGFR1 transcript variant suggestive of internal tandem duplication in 1, KANK2::NTRK2 fusion in 1). All tumors also had CDKN2A/B homozygous deletion and 9 lost ATRX expression. Tumors were infratentorial (n=8), supratentorial (n=7), and spinal (n=2) at initial presentation. First line treatment included surgery followed by chemoradiation with temozolomide (n=12), surgery followed by radiation (n=4), radiation alone (n=1), and surgery alone (n=1). Gross total resection was achieved in 3/17, 8/17 had subtotal resection and 5/17 had biopsy. 14/17 received a median RT dose of 5700 cGy (range, 4005–6000) in 30 fractions. The median follow-up duration was 34.9 months. 8 patients experienced disease progression. The median progression-free survival (mPFS) was 30.3 months (95% CI: 15.4–NR). 6/8 underwent surgery; 3/8 underwent RT. Systemic therapies were administered in 5/8 (lomustine, bevacizumab, pembrolizumab, temozolomide, trametinib, tovorafenib). 3/17 patients died due to progressive disease with an OS of 54.2, 94.6 and 17.4 months, respectively. The mOS for the whole cohort was 54.2 months (95% CI: 54.2-NR). CONCLUSION While the optimal management of this newly recognized entity has yet to be established, our cohort demonstrates a clinical behavior consistent with CNS WHO grade 3, aligning with current WHO interpretations.

Abstract Alzheimer’s Disease (AD) 1 is a progressive neurodegenerative disorder with limited therapeutic options, driving interest in drug repurposing to accelerate treatment discovery. Drug repurposing has emerged as a promising strategy to accelerate therapeutic discovery by repositioning existing drugs for new clinical indications. Recent computational repurposing approaches, including knowledge graph reasoning, transcriptomic signature analysis, and integrative literature mining, have demonstrated strong predictive capabilities 2 . However, these methods often yield divergent drug rankings, which makes it difficult to decide which candidates to advance for experimental follow-up and results in substantial gaps between computational predictions and feasible in vivo validation 2 .To bridge this computational-experimental gap, we proposed an advanced prioritization framework leveraging large language models (LLMs). Our method systematically evaluated three state-of-the-art (SOTA) and representative computational methods (TxGNN 3 , Composition-based Graph Convolutional Network (CompGCN) 4 , and a regularized logistic regression (RLR) 5 , to analyze both their predictive performance and pharmaceutical class distributions. By integrating the strengths and divergences of these models, we generated a unified, streamlined list of 90 candidate drugs for further prioritization. We then utilized an LLM-based agent to perform evidence synthesis from biomedical literature abstracts for each candidate. This process mimics expert manual curation but significantly reduces human effort and time by efficiently distilling vast textual data into actionable insights. Applying consistent and transparent selection criteria, we obtained a refined and prioritized list of drug candidates suitable for subsequent in vivo experimental validation. The robustness and clinical relevance of our framework were validated using real-world data from Alzheimer’s patient cohorts, clinical trial registries, and expert pharmacological reviews. This comprehensive validation confirmed that our LLM-driven approach enhances efficiency, consistency, scalability, and generalizability. By integrating computational predictions with scalable evidence synthesis and multifaceted validation, our framework facilitated rapid and informed prioritization of repurposed drugs. Our framework can potentially accelerate the translational pathway toward viable AD therapeutics. Moreover, the versatility of our framework can also be applied to drug repurposing efforts for other diseases beyond AD.

Abstract BACKGROUND Von Hippel-Lindau (VHL) disease is a hereditary cancer syndrome characterized by development of multiple neoplasms, including central nervous system (CNS) hemangioblastomas, renal cell carcinoma (RCC), pancreatic neuroendocrine tumors (pNETs), and retinal hemangioblastomas. Belzutifan, a hypoxia-inducible factor 2-alpha (HIF-2α) inhibitor, has demonstrated efficacy in treating VHL-associated tumors. This study evaluates our institutional experience with belzutifan in patients with VHL-related tumors. MATERIAL AND METHODS We conducted a retrospective cohort study across three Mayo Clinic sites, including patients aged ≥18 years with genetically confirmed VHL disease who received belzutifan between October 2021 and March 2025. Clinical/radiological data, and adverse events (AEs) were extracted from electronic health records. Tumor responses were assessed using RECIST v1.1 criteria for RCC, pNET, CNS hemangioblastoma. Retinal hemangioblastoma responses were evaluated through ophthalmologic assessments. RESULTS Forty-five patients were included (median age 44 58% female). Sixty-seven percent had RCC, 91% had CNS hemangioblastomas, 53% had pNETs, and 62% had retinal hemangioblastomas. The median duration of belzutifan therapy was 22.6 months (range 1.0-41.4 months). Among patients with RCC (n=26), overall response rate (ORR) was 19% and median time to best response (MTBR) was 7.4 months. Five patients had partial response (PR), 15 had stable disease (SD), and 1 had progressive disease (PD). For CNS hemangioblastomas (n=41), ORR was 12%, MTBR was 6.2 months. 5 patients had PR, 30 had SD, and none had PD. For pNET (n=17), ORR was 41%, MTBR was 8.2 months. One patient had CR, 6 patients had PR, 6 had SD, none had PD. For retinal hemangioblastomas (n=28), 6 (21%) showed improvement, 9 (32%) remained stable, and 3 (11%) showed progression. MTBR was 6.7 months. Treatment-related AEs occurred in 98% of patients. Common AEs included anemia (89%), fatigue (80%), hypoxia (18%), and headache (13%). Grade 3 AEs were observed in 20% of patients, including anemia (7%), hypoxia (9%), fatigue (4%), pneumonitis (2%), loss of consciousness (2%). One patient experienced a grade 4 event (status epilepticus). Anemia management involved iron supplementation (n=11), RBC transfusion (n=3), dose reduction (n=2), treatment holiday (n=8), permanent discontinuation (n=1). Hypoxia management included dose reduction (n=1), treatment holiday (n=3), discontinuation (n=1). CONCLUSION Belzutifan shows clinical activity across various VHL-associated neoplasms in real-world practice, with a manageable safety profile. The lower ORR compared to the phase III trial may reflect differences in baseline disease, including lower tumor burden in our cohort. These findings support its continued use in VHL disease, with attention to monitoring and managing treatment-related AEs.

Abstract BACKGROUND Gliomas are rare and aggressive CNS tumors with limited survival, making clinical trial (CT) participation indispensable, particularly in progressive cases. Cross-national disparities in glioma CT access remain underexplored. This study investigates temporal trends and socioeconomic correlates of glioma CT activity across eight European countries, using lung cancer trials as a benchmark. MATERIAL AND METHODS Glioma CTs registered after 2004 and conducted in France, Germany, Italy, Denmark, Poland, Hungary, Greece, or Turkey were extracted from ClinicalTrials.gov. A comparable lung cancer dataset was created. National-level data on population, gross national income (GNI) per capita, human development index (HDI), and cancer incidence were obtained from public sources. Trial access was defined as active CTs per estimated annual new cases. RESULTS Of 3,292 glioma CTs globally, 640 involved at least one target country. France (n=287), Germany (n=192), Italy (n=151), and Denmark (n=61) hosted the most; Turkey (n=5), Hungary (n=13), Greece (n=10), and Poland (n=26) contributed minimally. Over time, France, Germany and Italy showed significant upward trends in glioma CT activity (p < 0.05). Denmark, despite lower absolute numbers, showed strong growth relative to population. Turkey remained the least active participant, with no significant increase in glioma trial activity. When adjusted for estimated glioma cases, Denmark had the highest trial access, followed by France and Germany. Trial access positively correlated with GNI per capita (ρ = 0.76, p = 0.028) and moderately with HDI (ρ = 0.69, p = 0.058). In contrast, lung cancer trials were more abundant and equitably distributed (p = 0.0078), without significant correlation with national socioeconomic indicators (ρ =0.14, p=0.7 gor GNI per capita and ρ =0.19 p=0.7 for HDI). Despite having similar or lower GDP per capita compared to other countries in the analysis, Poland and Hungary showed substantially higher lung cancer trial access than glioma trial access, highlighting the underrepresentation of glioma research in resource-limited settings. Notably, Turkey exhibited the lowest glioma CT access (0.0010 per patient), despite a moderate volume of lung cancer trials. CONCLUSION Glioma CT access varies widely across Europe and is closely tied to GNI and HDI, unlike lung cancer trials, which are more equitably distributed. These disparities may relate to differences in the availability of trained neuro-oncology professionals and structured care systems, warranting further study. Targeted policy efforts are needed to improve access and inclusion in glioma research across all regions.

Hepatitis D virus (HDV) infection remains a major cause of severe liver disease among hepatitis B virus (HBV)-infected patients, contributing to accelerated progression to cirrhosis and hepatocellular carcinoma. Pegylated interferon-α remains the first-line therapy for chronic HDV infection in most cases. However, despite its approval for HBV and hepatitis C virus (HCV) infections, its use in HDV is largely driven by a lack of other options and is constrained by its limited efficacy, suboptimal durability of response, and a substantial side effect profile. Meanwhile, bulevirtide, an entry inhibitor, became the first agent to be approved for use in chronic HDV infections by the European Medicines Agency (EMA), and several other therapies are currently being investigated as well. In this review, we provide updates on recent advancements in HDV treatment and novel therapies.

Abstract Aggregation and nuclear depletion of the RNA binding protein TDP-43 are the crucial pathological features of amyotrophic lateral sclerosis (ALS) and inclusion body myositis (IBM), two degenerative diseases of the CNS and muscle. The loss of TDP-43 nuclear function results in the aberrant inclusion of cryptic exons in mRNA transcripts, leading to the expression of de novo proteins. Clonally expanded and highly differentiated CD8 + T cells have been observed in individuals with TDP-43 proteinopathies and therapeutics modulating the T cell response have recently been found to extend survival. However, the target antigens mediating T cell activation have remained elusive. Here, we investigate whether the de novo proteins induced by aberrant cryptic splicing due to TDP-43 nuclear loss can act as neo-antigens. We detect the HDGFL2 cryptic peptide and multiple other TDP-43 cryptic exons in IBM skeletal muscle, where their presence correlates with enrichment of T cells and class I antigen presentation pathways. Furthermore, we identify epitopes deriving from HDGFL2 and IGLON5 cryptic peptides which are recognized by clonally expanded and functionally differentiated populations of CD8 + T cells in ALS and IBM Patients. Finally, we demonstrate that T cells engineered to express the identified TCRs can bind and activate in response to the cryptic peptide derived epitopes (cryptic epitopes) and are able to kill TDP-43 deficient astrocytes. This work identifies for the first time specific T cell antigens in ALS and IBM, directly linking adaptive immune response to TDP-43 pathology.

AbstractA thorough understanding of normal biliary anatomy, common variants, and surgically altered anatomy is essential for the success of biliary interventions. Variations in biliary anatomy are seen in up to 40% of patients and frequently influence procedural planning and outcomes. This review highlights classical biliary anatomy, its common variations, and the challenges posed by surgical modifications, such as those encountered after cholecystectomy, liver resection, or biliary reconstructions. Case-based examples are used to explore the implications of these variations and modifications on interventional approaches, including the management of bile leaks, strictures, and complex obstructions. Strategies incorporating advanced imaging and procedural techniques, such as rendezvous interventions, are discussed to address complications and optimize outcomes. This article provides a practical framework for interventional radiologists to navigate challenging biliary cases with confidence and precision.

AbstractPortosystemic collateral pathways are a significant concern in interventional radiology, frequently manifesting in patients with cirrhosis or portal vein thrombosis. These pathways can lead to severe clinical complications, including gastrointestinal bleeding, hepatic encephalopathy, and liver failure. A thorough understanding of the anatomy, hemodynamic alterations, and clinical implications of these shunts is crucial for interventional radiologists to provide effective treatment while minimizing risks. This article reviews the clinical presentations associated with portosystemic shunts, explores the anatomical variants and altered flow dynamics, and discusses the latest endovascular treatment strategies to optimize patient outcomes.