Purpose: Brain structure-function coupling (SFC), which reflects the degree to which anatomical structure supports neural function, is an emerging imaging marker in neurodegenerative diseases. However, its pathological underpinnings in Alzheimer's disease (AD) remain poorly understood. This study aimed to examine the association among amyloid pathology, SFC disruption and cognitive decline.
Methods: We included 173 participants from the SILCODE cohort, comprising cognitively unimpaired (CU) and cognitively impaired (CI) individuals. Amyloid pathology was quantified using [F]-florbetapir PET standardized uptake value ratios (SUVR). Structural connectivity (SC) was derived from diffusion-weighted MRI with probabilistic tractography, while functional connectivity (FC) was calculated from resting-state functional MRI. SFC was defined as the coefficient of determination from linear models predicting FC based on SC at regional level. Linear regression and mediation analyses were conducted to assess relationships between amyloid pathology, SFC, and multiple cognitive performances.
Results: Compared to CU individuals, CI participants exhibited increased regional SFC primarily within the default mode network regions (p < 0.05). In CI participants, amyloid pathology correlated with SFC across occipital lobe, precuneus and temporoparietal regions, which was specific by APOE ε4 status (p < 0.05). Mediation analyses revealed that SFC partially mediated the relationship between amyloid pathology and cognitive impairment (ab = -0.14, 95% CI [-0.27, -0.02]). Similar findings were replicated with plasma markers.
Conclusion: Amyloid pathology may underlie SFC disruptions, contributing to cognitive decline in AD. These findings suggest that SFC may serve as a potential biomarker for amyloid-related neurodegeneration and cognitive impairment.
Trial Registration: The SILCODE is listed on the ClinicalTrials.gov registry (SILCODE: NCT03370744).
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http://dx.doi.org/10.1007/s00259-025-07172-8 | DOI Listing |
J Immunol
February 2025
Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States.
Mitochondrial antiviral-signaling protein (MAVS) is a key adapter protein required for inducing type I interferons (IFN-Is) and other antiviral effector molecules. The formation of MAVS aggregates on mitochondria is essential for its activation; however, the regulatory mitochondrial factor that mediates the aggregation process is unknown. Our recent work has identified the protein Aggregatin as a critical seeding factor for β-amyloid peptide aggregation.
View Article and Find Full Text PDFAdv Sci (Weinh)
March 2025
State Key Laboratory of Medical Proteomics, National Chromatographic R. & A. Center, CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China.
Spatially resolved characterization of proteoforms has substantial potential to significantly advance the understanding of physiological and disease mechanisms. However, challenges remain regarding throughput and coverage. A robust method is developed for high-throughput proteoform imaging (HTPi) by combining matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI) and region-specific top-down proteomic analysis.
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January 2025
Department of Laboratory Medicine, St. Michael's Hospital, Unity Health & Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
There is considerable evidence for a role for metabolic dysregulation, including disordered purine nucleotide metabolism, in the pathogenesis of Alzheimer's disease (AD). Purine nucleotide synthesis in the brain is regulated with high fidelity to co-ordinate supply with demand. The assembly of some purine biosynthetic enzymes into linear filamentous aggregates called "cytoophidia" (Gk.
View Article and Find Full Text PDFSci Rep
March 2025
Department of Neurology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
Although most cases of logopenic variant primary progressive aphasia (lvPPA) are caused by Alzheimer's disease (AD), Lewy body disease (LBD) has also been reported. We assessed brain perfusion, atrophy, dopamine transporter (DAT) uptake, and language function among patients with lvPPA based on beta-amyloid. Thirty-three patients with lvPPA and 28 healthy controls (HCs) underwent MRI, F-florbetaben PET, and early- and late-phase DAT PET.
View Article and Find Full Text PDFJAMA Netw Open
March 2025
NeuroGenomics and Informatics Center, Washington University School of Medicine, St Louis, Missouri.
Importance: Age, sex, and apolipoprotein E (APOE) are the strongest risk factors for late-onset Alzheimer disease (AD). The role of APOE in AD varies with sex and ancestry. While the association of APOE with AD biomarkers also varies across sex and ancestry, no study has systematically investigated both sex-specific and ancestry differences of APOE on cerebrospinal fluid (CSF) biomarkers together, resulting in limited insights and generalizability.
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