Citations

BACKGROUND. Dementia is a rapidly expanding public health problem with major socio-economic burden. Insulin resistance (IR) is a prevalent but modifiable risk factor for dementia, yet its effects on brain structure, functional connectivity, and metabolism remain incompletely understood. METHODS. Regional brain glucose uptake (PET), volumes (MRI), functional connectivity (fMRI), and cognition (NIH Toolbox) was measured in 72 adults with or without markers of IR. To evaluate reversibility of IR-associated brain deficits, forty older adults with IR were randomized to forty weeks of metformin or placebo, and brain measures were repeated. As a proof-of-concept experiment, we developed a conditional brain-specific insulin receptor knockout mouse and assessed brain mitochondrial function and cognition. RESULTS. In older adults with markers of IR is associated with diminished total and regional brain volumes in areas critical for neuronal connectivity, memory, and learning, including cerebral white matter and the hippocampus. Reduced functional connectivity between brain regions detrimental for cognition was also noted. Further, we demonstrated that ATP production, essential for neuronal connectivity, was diminished in neuron-specific insulin receptor knockout mice accompanied by deficits in hippocampal- and prefrontal-dependent tasks. Forty weeks of metformin improved systemic insulin sensitivity concurrent to preserved brain glucose uptake, volume, and functional connectivity within specific regions central to decision-making and learning. Metformin was also associated with an improved composite measure of processing speed and working memory. CONCLUSION. These findings highlight IR as a key regulator of brain metabolism and support the concept that insulin sensitization can prevent neurobiological deficits in older people with IR.

ABSTRACT Background Primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are rare, chronic cholestatic liver diseases with heterogeneous progression and limited biomarkers of disease biology. Epigenetic age acceleration has been demonstrated in PSC and PBC, suggesting accelerated biological aging. DNA methylation–derived telomere length (DNAmTL) reflects replicative aging and cellular turnover, but its role in PSC and PBC remains unclear. We aimed to evaluate DNAmTL in PSC and PBC and its association with disease severity. Methods We analysed and compared DNAmTL and age‐adjusted DNAmTL among patients with PSC ( n = 474) versus PSC controls ( n = 484) and patients with PBC ( n = 291) versus PBC controls ( n = 291). Associations with clinical outcomes were assessed using nonparametric tests and multivariable logistic regression models. Correlations with primary sclerosing cholangitis Risk Estimate Tool (PREsTO) score and epigenetic age acceleration (AgeAccelGrim) were evaluated using linear regression. Results Patients with PSC demonstrated significantly shorter age‐adjusted DNAmTL compared with controls (median −0.036 vs. 0.016, p < 0.001). Patients with PBC also exhibited reduced DNAmTL relative to controls (median 6.814 vs. 6.885, p < 0.001). Within PSC, shorter DNAmTL was associated with cirrhosis (OR 0.21, 95% CI 0.06–0.69, p = 0.013) and advanced disease (OR 0.20, 95% CI 0.06–0.67, p = 0.009). Shorter DNAmTL was also observed in hepatic decompensation and hepatobiliary malignancy, including cholangiocarcinoma. DNAmTL inversely correlated with PReSTO score ( p < 0.001). DNAmTL was strongly inversely correlated with AgeAccelGrim in both PSC and PBC ( p < 0.001). Conclusion Cholestatic liver diseases are associated with shortened DNAmTL, which independently correlates with disease severity in PSC. Together with epigenetic age acceleration, these findings support a model of accelerated biological aging in PSC and PBC characterized by converging signatures of accelerated biological aging that may contribute to progressive biliary injury and fibrosis.

Introduction: Frontotemporal lobar degeneration (FTLD) is a devastating disease that commonly results in early onset dementia, yet its rarity and heterogeneity limit large-scale research and clinical trials. Remote monitoring via low-burden digital health tools may overcome these barriers. We evaluated clinical utility of passive smartphone monitoring in FTLD using a multi-domain mobile assessment platform. Methods: Participants were 567 adults (53% clinically normal, 21% prodromal FTLD, 26% symptomatic FTLD) who completed an in-person study visit and downloaded the ALLFTD Mobile App on their personal smartphones. The app delivered unsupervised cognitive tests and passively collected continuous data on battery percentage (proxy for smartphone use) and step count. Longitudinal follow-up included smartphone monitoring and annual in-person study visits. Primary analyses examined associations between passive smartphone features and markers of disease severity at baseline and longitudinally, and tested whether passive features added incremental value beyond app-based cognitive testing. Results: Passive smartphone features were feasible to collect and showed excellent reliability with <2 weeks of monitoring (ICCs>0.9). Features capturing smartphone use and movement demonstrated sensitivity to gold-standard clinical measures of disease severity both at baseline and longitudinally. A classification model combining passive features, the app-based cognitive composite score, and demographics detected longitudinal functional decline (AUC=0.89); passive features alone (AUC=0.84) performed comparably to a cognitive screener (AUC=0.85). Discussion: Passive smartphone monitoring is a valid, zero-burden measure of disease severity and progression in FTLD that adds modest incremental value beyond app-based cognitive testing. Findings support its use as a scalable digital endpoint in longitudinal FTLD research.

Cholangiopathies comprise a heterogeneous group of chronic liver diseases characterised by progressive bile duct injury, ductular reaction and fibrotic remodelling. Despite distinct aetiologies, these disorders share common cellular stressors that ultimately converge on cholangiocyte dysfunction and loss. In this context, programmed cell death has emerged as a central mechanism linking epithelial stress, immune activation and the development of biliary fibrosis. A range of regulated cell death pathways, including apoptosis, necroptosis, pyroptosis, ferroptosis and autophagy-dependent cell death, can be triggered in cholangiocytes in a disease-dependent and context-dependent manner. Growing evidence suggests that these pathways rarely act in isolation. Instead, they intersect through shared molecular nodes, forming integrated cell death programmes such as PANoptosis. Importantly, it is becoming clear that not only overt cell death but also sublethal activation of death-related signalling can perpetuate cholangiocyte dysfunction and fuel chronic disease progression. Current therapeutic strategies, such as ursodeoxycholic acid and peroxisome proliferator-activated receptor agonists, mainly aim to modify bile composition and improve biochemical parameters. However, they do not directly target the molecular networks governing cholangiocyte death, which may partly explain their limited impact on fibrosis and long-term outcomes. In this review, we synthesise current knowledge on regulated cell death mechanisms in cholangiopathies, highlight key conceptual and technical challenges that complicate their interpretation and therapeutic targeting, and discuss how sublethal death signalling may connect with senescence to sustain cholangiopathy progression and shape therapeutic perspectives.

Abstract The 6th Edition of the World Health Organization Classification of Digestive System Tumours has introduced two new categories of gastric neuroendocrine tumors, reflecting recent data on subtypes that do not conform to the three established subtypes: type 1 (associated with autoimmune gastritis), type 2 (associated with Zollinger-Ellison Syndrome) and type 3 (sporadic). The new type 4 category is exceptionally rare and is caused by endogenous dysfunction of parietal cell proton pumps, potentially secondary to mutation of ATP4A. Type 5 gastric NETs are caused by chronic pharmacologic inhibition of the parietal cell proton pump, typically due to proton pump inhibitor use, and are increasingly common. Given the relatively low malignant potential of the new subtypes compared to sporadic (type 3) gastric NETs, it is important that clinicians and pathologists recognize these entities, limiting radical surgical resections when unnecessary.