Citations

Abstract BACKGROUND: Tumor-specific T cells are often characterized by reduced TCR signaling due to central and peripheral tolerance pathways that limit their responsiveness. These signals are further weakened by insufficient co-stimulation and active co-inhibitory pathways, collectively establishing a high threshold for activation. The integration of antigen recognition with co-stimulatory and inhibitory cues ultimately determines whether a T cell becomes activated or remains tolerant. Early TCR signaling must therefore be precisely regulated to prevent autoreactivity while still supporting protective immunity. Although phosphorylation and ubiquitination are well-established regulators of proximal TCR signaling, additional post-translational mechanisms remain less defined. SIRT2, a cytosolic NAD+-dependent deacetylase with emerging roles in immune regulation, has not been examined in the context of TCR signaling. METHODS: We evaluated proximal TCR signaling events in wild-type and SIRT2-deficient T cells using flow cytometry, immunoblotting, calcium flux assays, and RNA-sequencing. SIRT2-associated pathways were defined by mapping its interactome and acetylated substrates through mass spectrometry and immunoprecipitation. We screened LCK post-translational modifications by mass spectrometry and assessed SIRT2 enzymatic activity using an HPLC-based deacetylase assay. Conformational effects of LCK modification were examined using fluorescence-polarization binding assays and AlphaFold structural modeling. SIRT2 was deleted in human tumor infiltrating lymphocytes (TILs) via CRISPR/Cas9, and the impact of SIRT2 targeting was tested in lung cancer patient-derived xenograft models reconstituted with autologous TILs. RESULTS: SIRT2 deficiency amplified proximal TCR signaling, leading to elevated phosphorylation of early signaling mediators and increased calcium flux in both naïve and anergic T cells. Loss of SIRT2 also altered thymic selection dynamics and expanded TCR repertoire diversity. Mechanistically, SIRT2 interacted with and deacetylated LCK, the initiating kinase of proximal TCR signaling. Mass spectrometry identified lysine K228 in the LCK linker region as a SIRT2-regulated deacetylation site that governs LCK conformation and kinase activity. Functionally, SIRT2 inhibition in exhausted mouse and human TILs restored TCR signaling capacity and improved anti-tumor responses. CONCLUSION: Here we identify SIRT2-regulated deacetylation of LCK as a previously unrecognized mechanism that sets the strength and threshold of proximal TCR signaling. Accordingly, SIRT2 targeting reverses the exhausted phenotype of tumor-reactive T cells. Citation Format: Imene Hamaidi, Pingyan Cheng, Soo Young Jun, Min-Hsuan Wang, Min Zhang, Odesha Taylor, Luis Lopez-bailon, Ismail Can, Bin Fang, Anders Berglund, Bradford Perez, Ben Creelan, Andriy Marusyk, Virginia Shapiro, Haitao Ji, Jose R. Conejo-Garcia, Sungjune Kim. Sirt2 dictates TCR activation thresholds through post-translational control of LCK conformational state [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 4250.

Abstract Background and Aims Stroke and systemic embolism are recognized but poorly characterized complications of atrial fibrillation (AF) and left atrial flutter (AFL) catheter ablation. Their incidence, outcomes, and procedural associations remain insufficiently defined. Methods Retrospective global registry was initiated by the European Heart Rhythm Association Scientific Committee. A secure database captured data from ablation centres worldwide on general AF and left AFL ablation activity, as well as detailed information on patients with symptomatic embolic events between 2017 and 2024. Results Overall, 204 centres reported 335 743 ablation procedures and 550 embolic events (incidence 0.16%). Centre-level rate ranged from 0% to 3.1%. Most events were cerebral (94%), followed by peripheral (5%), and combined (1%). Coronary air embolism accounted for 62% of all peripheral events. Intraprocedural events occurred in 93 patients (17%), within 72 h in 357 (78%) and beyond 72 h in 100 (22%); 128 cases (23%) were diagnosed after hospital discharge. Nonparoxysmal AF (0.23% vs 0.15%; P < .001), centre experience, and ablation energy source (radiofrequency, 0.16%; cryoballoon, 0.16%; pulsed field ablation, 0.25%; laserballoon, 0.88%; P < .001) were associated with embolic risk. Median NIHSS score after stroke was 4 (interquartile range, 2–9). Three-month follow-up was available for 518 patients with embolism (95%): 181 (35%) had sequelae and 16 (3%) died. Conclusions Symptomatic embolic events are infrequent but associated with significant morbidity and mortality. Most events occur early, though a substantial proportion arise later. Higher event rates were observed with laser and possibly with pulsed field ablation. A greater centre experience was associated with a lower embolism incidence.

Variants in TMEM106B and GRN , which encode lysosomal proteins, interact through unknown mechanisms to increase the risk of age-related cognitive decline and neurodegeneration. Here, we show that these variants converge on a single molecular intermediate: the cleaved intra-lysosomal fibril core of TMEM106B, a precursor to amyloid fibrils that accumulate in the aging brain. A protein-coding TMEM106B risk variant (p.T185) drives fibril core accumulation by impairing its degradation and GRN risk variants amplify this effect. Mice over-expressing the fibril core develop hallmarks of neurodegeneration, and cryo-electron tomography reveals intra-lysosomal fibrils in cultured neurons, mice, and diseased human brain. In GRN -mutation carriers, in whom fibril burden is greatest, fibrils extrude through ruptured lysosomal membranes. These findings identify intra-lysosomal TMEM106B fibrillization as a convergent neurodegeneration mechanism and potential therapeutic target.

ABSTRACT Introduction Non‐muscle invasive bladder cancer (NMIBC) is a chronic disease with a lifelong treatment burden that may cause substantial urinary morbidity. Such quality‐of‐life changes remain understudied. We therefore evaluated the incidence and predictors of treatment for overactive bladder (OAB) among older adults following diagnosis of NMIBC. Materials and Methods We identified adults aged 66–89 years with newly diagnosed NMIBC from 2007 to 2017 in the linked SEER‐Medicare database. We examined the incidence of treatment initiation for OAB following initial transurethral resection of bladder tumor (TURBT) and evaluated associations with baseline characteristics using Cox regression. Results We identified 9,819 patients, of whom 68% had Ta disease, 29% had T1 disease, and 4% had CIS. Within the first 12 months of TURBT, 7% of patients received treatment for OAB, and this increased to 15% of patients at 5 years. In the first year, the most utilized therapies were anticholinergic medications (early 3.72%, late 2.74%) and beta‐3 agonists (early 0.11%, late 0.32%), while procedural OAB therapy utilization was rare (0.2%). On multivariable analysis, female gender (HR 1.26, 95% CI 1.11–1.42), congestive heart failure (HR 1.21, 95% CI 1.03–1.43), and T1 tumor stage (HR 1.27, 95% CI 1.12–1.44 vs. Ta) were independently associated with an increased risk of OAB treatment. Conclusions The incidence of OAB requiring treatment among patients with NMIBC is substantial, with approximately one in six patients receiving treatment by 5 years after diagnosis. Predictive clinicopathologic features for OAB treatment—including, sex, high‐risk tumor features, and repeat TURBT—may be useful for clinical counseling.

Abstract Context Most of the patients included in the clinical trials and real-world studies with osilodrostat only include patients with adrenocorticotropic hormone dependent Cushing syndrome (CS), while data on the efficacy and safety of osilodrostat in patients with adrenal CS is scarce. Objective To assess the efficacy and safety of osilodrostat in adrenal CS. Methods International study of patients with adrenal CS: patients treated with osilodrostat at any time were enrolled in the safety evaluation and those treated for longer than 4 weeks, in the efficacy evaluation. Patients were classified as responders if they experienced a reduction in urinary free cortisol (UFC) >50% (complete responders when UFC levels were below the upper limit of normal [ULN] and partial responders if there was a reduction >50% but not normalization). Results Twenty-eight patients with adrenal CS were enrolled: 16 with adrenocortical carcinoma and 12 with benign disease. Osilodrostat was used in monotherapy in 22 patients and in combination with metyrapone in 6 cases. In those patients treated for longer than 4 weeks (n = 21), 66.7% were classified as responders (28.6% with complete response and 38.1% with partial response), and for those treated for longer than 12 weeks, the rate of response increased to 87.5% The use of osilodrostat as a nonfirst-line therapy (odds ratio 15.0, P = .010) was a predictor of response. Osilodrostat led to a significant decrease in systolic blood pressure and body weight (P < .05). Nine patients developed one or more adverse events and in 56% (n = 5) led to osilodrostat discontinuation. Conclusion Osilodrostat controls hypercortisolism in 66.7% of patients with adrenal CS treated for longer than 4 weeks and in 87.5% of cases treated for longer than 12 weeks, with a positive impact on blood pressure and body weight. Patients who received osilodrostat after other previous steroidogenesis inhibitors have a higher probability of response.

Abstract Rare Mendelian disorders affect 300-400 million people globally. Although genetic testing has become widely adopted, gene-specific evidence for tailored variant interpretation remains scattered across resources. We present Gene Portals, a framework for gene-centered multimodal knowledge bases that co-localize expert-harmonized clinical data, functional assays, population variation, structural annotations and gene-specific ACMG/AMP specifications within a single resource. A modular interface integrates this unified evidence with VCEP-refined ACMG specifications to enable automated gene-specific variant classification, infer molecular mechanisms, and support cross-gene analyses. We demonstrate the framework’s utility across five Gene portals spanning eleven neurodevelopmental disorder-associated genes, integrating data from 4,423 individuals with 2,838 unique variants, 36,149 ClinVar submissions, and 1,044 expert-curated molecular readouts. By organizing evidence that is otherwise dispersed across multiple sources into a unified, queryable framework, the SCN, GRIN, CACNA1A, SATB2 and SLC6A1 Gene Portals became widely used community resources and provide an extensible template for standardized rare-disease variant interpretation and mechanism-aware discovery.

Background Uncontrolled hypertension is common in chronic kidney disease (CKD) patients. Electro-hydraulic acoustic therapy (eHAT) is a non-invasive treatment that may lower blood pressure (BP), but its safety and efficacy in CKD remain unclear. This study aimed to evaluate eHAT's feasibility and safety in this population. Methods In this single-arm, prospective, single-center proof-of-concept study, CKD patients received six eHAT treatments over three weeks. BP was assessed in-office (attended and unattended) at baseline and at 4-, 12-, 24-, and 48-weeks post-treatment. Ambulatory BP monitoring (ABPM) was performed at baseline, 12, and 48 weeks. The primary endpoint was change in systolic office BP (OBP) from baseline to 12 weeks. Secondary endpoints included additional BP measurements, kidney function, and safety. Results Fifteen patients completed all follow-ups. At 12 weeks, mean systolic OBP decreased by 9.73 mmHg (SD 14.77; p = 0.0032) and remained significantly lower at 24 weeks (−7.67 mmHg; p = 0.0335) and 48 weeks (−19.40 mmHg; p < 0.0001). Diastolic OBP reductions were significant at 12 ( p = 0.0413) and 48 weeks ( p = 0.0022). By 12 weeks, 26% of participants reduced the number or dose of antihypertensive medications. Kidney function remained stable throughout. No safety signals were detected. Conclusion Our study highlights the feasibility and tolerability of eHAT in patients with CKD and HTN. Nonetheless, due to the small sample size and lack of a control group, these findings should be considered preliminary.