Citations

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)

Background The management of osteochondral lesions of the talus (OLT) is challenging, with 2 main options being conservative and surgical management. Orthobiologic therapies come to bridge the gap between these 2 options; however, inconsistencies in indication, composition, and heterogeneous evidence limit clinical decision-making. To address these challenges, 3 International Congress Meetings on Cartilage Repair of the Ankle were convened in Pittsburgh, USA (2017), Dublin, Ireland (2019), and New York, USA (2025) to establish agreement on the role of conservative management and injectable orthobiologic strategies in the treatment of OLT. Methods Seventy-five multidisciplinary experts from over 25 countries and 1 territory participated in a structured Delphi-based consensus process. Blinded surveys, structured questionnaires, and in-person discussions were used to develop and refine statements, supported by literature review and graded evidence (A1–E). Consensus strength was defined as consensus (51%-74%), strong consensus (75%-99%), or unanimous (100%) Results In total, 29 consensus statements were achieved across the 3 meetings. Strong agreement was reached regarding indications and expected outcomes of conservative management, including the role of immobilization and appropriate timing for surgical intervention. Orthobiologic injections, including platelet-rich plasma, concentrated bone marrow aspirate, and hyaluronic acid, were considered appropriate in select patients with persistent symptoms, although no superiority was demonstrated among formulations, preparation methods, or injection strategies. When used as adjuncts to surgical procedures, orthobiologics may improve radiological outcomes, with limited evidence for improvement in clinical outcomes. Technical considerations, including preferred harvest sites and a lack of standardized preparation protocols, were identified, along with key principles for patient counseling Conclusion These international consensus statements establish a standardized framework for the conservative management and use of injectable orthobiologic therapies in OLT. By clarifying indications, technical considerations, and current limitations, this work aims to improve consistency in clinical practice, guide treatment decision-making, and inform future research.

BACKGROUND: Technetium-based cardiac amyloid radionuclide imaging enables noninvasive diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM), but conventional planar and visual semiquantitative approaches have important limitations. We developed the quantitative 3-dimensional Mayo 3D Score, defined as the ratio of mean left ventricular myocardial radiotracer uptake to right atrial blood-pool uptake using computed tomography (CT)-fused single-photon emission CT (SPECT) volumes of interest, and sought to validate its diagnostic performance against myocardial pathology. METHODS: Consecutive patients who underwent 99m Tc-pyrophosphate SPECT/CT at Mayo Clinic for suspected ATTR-CM between June 2017 and January 2025 with archived myocardial tissue were included. Baseline characteristics, including demographics, echocardiogram, biomarkers, visual semiquantitative, and Mayo 3D Score metrics, were collected. Myocardial specimens underwent histopathologic confirmation of amyloid, with amyloid subtype determination and further semiquantitative grading of amyloid burden and deposition patterns. RESULTS: Among 230 patients (median age, 72 years; 78% male), 107 (47%) had ATTR-CM, of whom 9 had hereditary ATTR-CM. The Mayo 3D Score showed excellent discrimination against pathology (area under the receiver operating characteristic curve, 0.92 [0.88–0.96]), exceeding planar Perugini (0.87 [0.83–0.92]; P =0.006), and heart-to-contralateral lung ratio (0.86 [0.81–0.91]; P =0.004) and comparable to SPECT Perugini (0.90 [0.86–0.94]; P =0.12). A cutoff ≥1.0 yielded 86.0% sensitivity, 92.7% specificity, 91.1% positive predictive value, and 88.4% negative predictive value. Among ATTR-positive cases, the Mayo 3D Score correlated strongly with semiquantitative amyloid burden (Spearman ρ=0.69), was higher in pericellular than nodular deposition patterns ( P <0.001), and was not associated with vascular involvement ( P =0.42). CONCLUSIONS: In patients with suspected ATTR-CM undergoing 99m Tc-pyrophosphate SPECT/CT, the Mayo 3D Score demonstrated superior diagnostic performance compared with planar metrics and comparable to SPECT Perugini, while correlating with myocardial ATTR burden and deposition patterns on pathology. These findings support its integration as a quantitative adjunct within clinical diagnostic ATTR-CM workflows.

ABSTRACT Aims Metabolic dysfunction‐associated steatotic liver disease (MASLD) is increasingly linked to cognitive decline, yet the hepatic factors associated with imaging‐derived neurovascular coupling (NVC) remain unclear. This study aimed to investigate whether liver stiffness or liver fat content was more closely associated with resting‐state CBF‐ReHo surrogate measures. Materials and Methods A total of 130 participants including 98 MASLD patients and 32 age‐ and education‐matched healthy controls (HCs) underwent clinical assessment, neuropsychological testing, and multi‐modal MRI. Liver stiffness and fat content were quantified using MR elastography (MRE) and MRI‐proton density fat fraction (PDFF). Imaging‐derived NVC was assessed using global cerebral blood flow (CBF)‐regional homogeneity (ReHo) coupling and voxel‐wise CBF/ReHo ratios, interpreted as resting‐state surrogates rather than direct stimulus‐evoked NVC. Multivariable regression and exploratory mediation analyses were employed. Results Compared to HCs and patients with lower liver stiffness (MASLD_low), those with higher liver stiffness (MASLD_high) showed reduced global CBF‐ReHo coupling and altered CBF/ReHo ratios, primarily localized to the bilateral superior temporal pole/superior temporal gyrus (TPOsup). In multivariable regression, liver stiffness remained independently associated with TPOsup CBF/ReHo ratios ( p < 0.001). Exploratory mediation analysis showed a statistically significant indirect association between hepatocellular injury markers and TPOsup CBF/ReHo ratios involving MRE‐derived liver stiffness (95% CI: 0.0795–0.2790). Conclusions Within this cohort and the observed PDFF range, MRE‐derived liver stiffness was more closely associated with imaging‐derived NVC surrogate measures than liver fat content in MASLD. These findings are hypothesis‐generating and require validation in longitudinal studies.

BACKGROUND: Primary aldosteronism (PA) is a common and treatable cause of hypertension, yet data on the durability of medical treatment response beyond the first year are limited. Using the PA medical treatment outcomes framework, we evaluated long-term biochemical and clinical outcomes and factors associated with treatment response. METHODS: We conducted an international, multicenter, observational cohort study across 27 centers on 4 continents. Adults with PA treated with mineralocorticoid receptor antagonists and/or epithelial sodium channel blockers between 2016 and 2021 were included if follow-up data were available at ≥12 months. Biochemical and clinical responses were classified as complete, partial, or absent using PA medical treatment outcomes criteria. Ordinal logistic regression identified determinants of a favorable treatment response. RESULTS: The cohort included 1292 patients (47.5% women, mean age 52 years) with a median follow-up of 34 months (interquartile range, 21–51). At ≥12 months, 58.3% achieved a complete biochemical response, and 20.8% achieved a complete clinical response, with only 5% showing no response. Determinants of a favorable biochemical response included lower aldosterone and lateralization index, and higher renin and potassium levels at baseline. In those taking spironolactone, a higher daily dose was also associated with a favorable biochemical response. Determinants of a favorable clinical response included female sex, lower body mass index, shorter duration of hypertension, and absence of hypertension-mediated organ damage. CONCLUSIONS: Targeted medical therapy for PA can deliver sustained biochemical and clinical benefits. Early disease detection and adequate dose titration are highly actionable determinants of long-term treatment success.

Abstract Background Cardiac magnetic resonance elastography (MRE) allows the non-invasive quantification of myocardial stiffness, but long-interval reproducibility data at 3.0 T single-frequency 140-Hz remain limited. Purpose To evaluate the short- and long-interval reproducibility of 3.0 T cardiac MRE for left ventricular (LV) myocardial stiffness across healthy volunteers and patients with conditions associated with elevated myocardial stiffness. Materials and Methods This prospective single-center study included 69 participants: 60 healthy volunteers and 9 with cardiovascular disease (6 with aortic stenosis and 3 with long-standing hypertension). All participants underwent baseline cardiac MRE (scanner: Signa Premier 3.0 T, GE Healthcare, driver: Resoundant), an immediate short-interval rescan (SIR) within 5 minutes, and a long-interval rescan (LIR) after approximately 1 month. Left ventricular myocardial stiffness and octahedral shear strain signal-to-noise ratio were measured independently by 2 readers. Reproducibility was assessed using Bland-Altman analysis, intraclass correlation coefficients (ICCs), within-subject coefficient of variation, standard error of measurement, and smallest detectable change at the 95% confidence (SDC95) level. Results Baseline LV myocardial stiffness was higher in the disease group than in healthy volunteers, 11.73 ± 1.01 kPa and 7.80 ± 0.70 kPa (mean ± SD; P &lt; .001), respectively. Inter-reader agreement was excellent across all timepoints, with ICCs of 0.970 at baseline (95% CI, 0.953-0.982), 0.966 for SIR (95% CI, 0.945-0.979), and 0.962 for LIR (95% CI, 0.939-0.976). Within-reader scan-rescan reproducibility was also excellent. For Reader 1, stiffness ICC was 0.979 for the SIR (95% CI, 0.966-0.987) and 0.957 for the LIR (95% CI, 0.932-0.973), with SDC95 values of 0.616 kPa (95% CI, 0.528-0.741) and 0.869 kPa (95% CI, 0.744-1.044), respectively. Reader 2 showed excellent reproducibility, with ICCs ≤0.943. Conclusions 3D single-frequency 140-Hz cardiac MRE at 3.0 T provides excellent short- and long-interval reproducibility for LV myocardial stiffness quantification. The SDC95 values may help distinguish true longitudinal stiffness changes from measurement variability.

Importance In vivo biomarkers for detecting neuropathologies from repetitive head impacts (RHI), including chronic traumatic encephalopathy (CTE), are needed. Objective To evaluate the utility of plasma phosphorylated tau 217 (p-tau217), assess its performance as a beta-amyloid (Aβ) biomarker in participants with RHI exposure at risk for CTE, and explore concordance with CTE neuropathology in a postmortem subsample. Design, Setting, and Participants This longitudinal, multicenter, case-control study used data from the Diagnostics, Imaging, and Genetics Network for the Objective Study and Evaluation of CTE (DIAGNOSE CTE) Research Project, collected from September 2016 to October 2023. Participants were former American football players (case participants) and asymptomatic men unexposed to RHI (control participants). A subsample had available neuropathologic data. Exposures RHI, traumatic encephalopathy syndrome (TES) diagnoses, and levels of CTE certainty. Main Outcomes and Measures Plasma p-tau217 (classified as positive [≥0.63 pg/mL], intermediate [0.40-0.62 pg/mL], and negative [&amp;lt;0.40 pg/mL]), Aβ–positron emission tomography (PET; 18 F-florbetapir; with Aβ-positive defined as a standardized uptake value ratio [SUVR] ≥1.10), and tau-PET ( 18 F-flortaucipir). TES diagnoses were assigned by multidisciplinary consensus conference. Analyses of postmortem brains controlled for age, race, and APOE ε4 status. Results Among 231 participants (mean [SD] age, 57.75 [8.25] years), 177 were former football players (117 professional and 60 college) and 54 were unexposed participants. Former football players had higher baseline mean (SD) p-tau217 concentrations than unexposed participants (0.35 [0.26] pg/mL vs 0.27 [0.14] pg/mL; P = .008), although this was driven by a higher proportion of Aβ-PET–positive participants among former players. Plasma p-tau217 increased over time across the sample (B = 0.207 [95% CI, 0.117-0.298]; P &amp;lt; .001), with no significant time × exposure group interactions. Among football players, p-tau217 showed no time × group interactions with TES diagnosis, TES-CTE certainty, or RHI metrics. Higher p-tau217 concentration correlated with higher global Aβ-PET SUVR (B = 0.058 [95% CI, 0.053-3.501; P = .01), with a few discordant cases (5 participants were p-tau217–negative and Aβ-PET–positive; 7 participants were p-tau217–positive and Aβ-PET–negative). P-tau217 had similar areas under the curve for projecting Aβ-PET positivity as cerebrospinal fluid (CSF) p-tau181/Aβ42 and CSF Aβ40/42 measures (p-tau217: AUC, 0.88 [95% CI, 0.80-0.96]; CSF p-tau181/Aβ42: AUC, 0.89 [95% CI, 0.79-1.00]; CSF Aβ40/42: AUC, 0.85 [95% CI, 0.72-0.98]). Among 9 brain donors, 6 had CTE (stages II-IV; none with Alzheimer disease). Seven had negative or intermediate p-tau217, concordant with Aβ-PET. Two p-tau217 outliers with stage III CTE had normal concentrations upon additional testing. Conclusions and Relevance The findings of this study suggest that plasma p-tau217 concentration is unlikely to be useful for the detection of CTE, but it does show utility for ruling out Aβ pathology in participants at risk for CTE.

Cytotoxic T cells produce the cytokine interferon-γ (IFN-γ). We sought to determine whether IFN-γ directly kills target cells and found that T cells used IFN-γ to kill murine melanoma cells lacking the kinases TBK1 and IKKε. In the absence of both kinases, IFN-γ induced the production of TNF receptor 1 (TNFR1) and the sensor Z-DNA binding protein 1 (ZBP1) in the tumor cells to stimulate receptor-interacting protein kinase 1 (RIPK1)–dependent apoptosis in a cell-autonomous manner. IFN-γ also enhanced the activation of nuclear factor κB (NF-κB) signaling in a TNFR1-dependent manner in cells deficient in both TBK1 and IKKε. Because IFN-γ–induced apoptosis occurred in a transcription-dependent manner with slow kinetics, STAT1 and NF-κB cooperated to activate the expression of inflammatory genes in the dying cells. Thus, IFN-γ–induced cell death was accompanied by an inflammatory signature in the absence of TBK1 and IKKε. TBK1 and IKKε not only mediated the induction of type I IFN but also inhibited RIPK1-dependent death and NF-κB–dependent inflammation. Therefore, we propose that these kinases may have gained these intertwined functions so that cells infected by pathogens that produce antagonists of TBK1 and IKKε are eliminated by IFN-γ–secreting T cells in an inflammatory manner to compensate for the inhibition of type I IFN production.

Abstract How glial cells sense and regulate neuronal hypoactivity remains poorly understood. Using in vivo imaging in anesthetized, sleeping, and behaving mice, we identified a glial purinergic signaling mechanism that converts neuronal hypoactivity into local circuit regulation. Cortical hypoactivity increased spatially confined ATP release through astrocytic pannexin-1 hemichannels, which were structurally enriched near perisomatic parvalbumin-positive boutons. Local ATP release directed microglial process movement and stabilized bulbous endings through microglial P2Y12 signaling, accompanied by localized Ca²⁺ activity in microglial processes. Disruption of astrocytic pannexin-1 or microglial P2Y12 impaired bulbous-ending stabilization and abolished rebound increases in neuronal activity during emergence from anesthesia. Similar ATP release and bulbous-ending formation were observed during chemogenetic neuronal silencing or natural sleep in freely behaving mice. These findings identify astrocyte-to-microglia purinergic signaling as a mechanism that converts neuronal hypoactivity into synapse-selective microglial regulation of circuit activity.

Background: Integrating machine learning (ML) with population pharmacokinetic (PPK) modeling may improve therapeutic drug monitoring predictions. Methods: Tacrolimus trough concentrations from lung transplant patients were split into a training data set (1151 concentrations in 80 patients) and a testing data set (224 concentrations in 20 patients). A PPK model was developed using NONMEM, followed by the development of 10 ML models to fit individual pharmacokinetic parameters from the PPK model with Bayesian forecasting. The best performing ML model was selected as the final model. Both the final PPK and ML models were compared for prediction performance. A web-based dashboard was established with R-shiny to recommend dosing regimens based on patient data. Results: In the PPK model, postoperative days, hematocrit, aspartate aminotransferase, tacrolimus daily dose, coadministered voriconazole or posaconazole, and the CYP3A5*3 genotype were identified significant covariates on the clearance. The Cubist ML model outperformed the PPK model, showing lower root mean squared error for tacrolimus concentrations in the testing data set. An online web-based precision dosing dashboard was created, accessible at (https://tac-dose-ml.shinyapps.io/shiny/). Conclusions: Integrating ML with PPK modeling could yield superior tacrolimus concentration predictions for lung transplant patients, offering an efficient alternative to Bayesian forecasting. The online dashboard provides rapid, individualized dosing recommendations.