Alzheimer's Research & Therapy最新文献

Introduction: Systemic inflammation has been identified as a key factor in neurodegeneration but the value of circulating inflammatory proteins in dementia risk prediction and their causal role has not been elucidated.

Methods: We leveraged proteomic data from 43,685 UK Biobank participants to investigate associations between 728 Olink inflammatory proteins and incident dementia using Cox proportional-hazards (Cox-PH) models. We used Cox-PH with LASSO regularisation to calculate a sparse signature of inflammatory proteins (ProSig) predicting incident dementia. Linear regressions assessed the association between ProSig and individual proteins with brain image-derived phenotypes and Brain Age in participants with available neuroimaging data (n = 4,106). Formal mediation analyses investigated whether inflammatory proteins mediated associations between genetic and modifiable risk factors and dementia outcomes. Mendelian randomisation (MR) tested the causal relationship between inflammatory proteins and dementia outcomes.

Results: 218 inflammatory proteins were individually associated with incident dementia in Cox-PH models (p_FDR < 0.05). A 20-protein signature significantly improved the prediction of incident dementia beyond known risk factors. TNFRSF11B, a protein linked to vascular damage, was associated with both incident dementia and reduced hippocampal volume. Two proteins, sFRP4 and MEPE, were linked to reduced Brain Age, with sFRP4 also being protective against dementia. Mediation analyses indicated that TNFRSF11B, APOE and C7 may partially mediate associations between modifiable risk factors and dementia. MR analyses suggested protective causal effects of TNFSF13 and IL17D.

Conclusions: By triangulating evidence, this study shows that inflammatory proteins improve dementia risk prediction and play heterogeneous roles in dementia pathophysiology.

Background: Alzheimer's disease is characterized by intertwined pathologies including neuroinflammation, driven by microglial dysfunction, and metabolic disturbances such as lipid dyshomeostasis. Mesenchymal stem cell-derived exosomes (MSC-Exos) hold therapeutic promise, Still, it is unknown whether they can simultaneously address these co-occurring impairments via specific molecular cargos, such as long non-coding RNAs (lncRNAs).

Methods: Transcriptome sequencing of exosomes derived from human umbilical cord mesenchymal stem cells (hUC-MSCs) revealed high expression of the long noncoding RNA ENST00000629969 (hereinafter referred to as lncRNA-9969). We isolated exosomes from hUC-MSCs (WT-Exo) and established human umbilical cord blood mesenchymal stem cells stably knocked down for lncRNA-9969 via siRNA, from which corresponding exosomes (KD-Exo) were isolated. Cross-species analysis identified the mouse homolog of lncRNA-9969 as ENSMUST00000200021 (hereinafter referred to as lncRNA-0021). Cellular experiments employed an Aβ₂₅₋₃₅-induced SH-SY5Y cell model to evaluate the protective effects of exosomes. In animal experiments, 6-month-old APP/PS1 mice received biweekly tail vein injections of WT-Exo or KD-Exo for 4 weeks. Phenotypic and mechanistic analyses were subsequently conducted using the Morris water maze, Western blot, immunofluorescence, qPCR, and transmission electron microscopy.

Results: In Aβ-injured SH-SY5Y cells, WT-Exo significantly attenuated cellular damage and promoted Aβ clearance, whereas the protective effect of KD-Exo was markedly reduced. In APP/PS1 mice, WT-Exo treatment significantly improved spatial memory deficits and upregulated hippocampal expression of synaptic proteins synaptophysin (Syn) and brain-derived neurotrophic factor (BDNF). Molecular mechanism studies demonstrated that lncRNA-0021 directly binds mmu-miR-6361. Through this ceRNA mechanism, exosome-delivered lncRNA activated the mTOR/p70S6K autophagy pathway, regulated lipid metabolism-related genes, promoted microglial polarization toward the protective M2 phenotype, and suppressed pyroptosis. These beneficial changes were not observed in the KD-Exo-treated group.

Conclusions: hUC-MSC-derived exosomes exert neuroprotective effects by delivering functional lncRNA-9969. Its highly conserved homolog in mice, lncRNA-0021, achieves coordinated multi-target regulation of neuroinflammation, pyroptosis, and metabolic disturbances by sequestering miR-6361 and activating downstream signaling pathways. This study elucidates the central role of exosomal lncRNAs in AD pathology and provides new insights for developing RNA-based multi-target therapeutic strategies.

Background: We aimed to evaluate whether double cutoff strategies for plasma pTau217 across multiple assay platforms improve tau PET positivity prediction compared with single cutoffs and support cost-effective clinical use.

Methods: We analyzed two cohorts: K-ROAD (n = 120; tau-enriched) and NA-ADNI (n = 280; tau-scarce). Tau PET positivity was defined within the temporal meta-ROI as SUVR > mean + 2 SD of Aβ-negative CU. Single and double cutoffs were compared for accuracy and misclassification-related costs.

Results: Single cutoffs showed good accuracy across most assays (AUCs > 0.80), except for C2N ratio. Double cutoffs modestly improved accuracy but expanded intermediate groups, in the tau-scarce cohort. Cost analyses revealed assay- and cohort-specific effects, with reductions in most settings but increases for Lilly-MSD and Janssen-Simoa.

Conclusion: Double cutoff strategies should be applied with attention to assay platform and cohort context. Accuracy gains were modest, but clinical utility lies in reducing misclassification costs and guiding confirmatory PET use.

Background: The oral microbiota has been associated with Alzheimer's disease (AD). However, earlier studies provided conflicting results using varying sampling methods, sequencing techniques, and statistics, as well as independent subjects.

Methods: To robustly identify disease-associated microbial features, we recruited patients and their healthy life partners from the same households sharing a more similar microbiota compared to independent individuals increasing statistical power via paired design and combined three different sequencing methods - including metagenomics-and several bioinformatic pipelines. We recruited 26 AD-patients and their life partners. Salivary and supragingival samples were collected and a clinical examination of the mouth was performed.

Results: Both groups showed comparable oral health. By focusing primarily on recurrently identified species across the different datasets we were able to identify a Core dysbiosis. This Core dysbiosis surprisingly spares the most central of oral diseases pathogens, namely Porphyromonas gingivalis. However, it includes numerous other species commonly associated with oral pathologies such as Prevotella nigrescens, Streptococcus anginosus, Dialister invisus, Anaeroglobus geminatus, Olsenella uli and Mogibacterium timidum. In contrast, more host-compatible species such as Prevotella melaninogenica or Streptococcus parasanguinis are identified in controls.

Conclusions: This is the first study using a combined sequencing approach and a paired study design to identify robust features of the oral microbiota of AD-patients. Although promising, the results should nevertheless be interpreted with caution, as the cross-sectional study design limits the possibilities of interpretation, and larger, longitudinal data are necessary for causal conclusions. However, this combined approach on multiple processing levels to identify intra-partnership differences still offers the possibility to better identify disease-associated microbial features potentially involved in AD-pathogenesis.

Trial registration: This study was prospectively registered at the German Clinical Trials Register (DRKS00023456) at the 30th of November 2020.

Background: Lecanemab is an anti-Aβ antibody approved in China for mild cognitive impairment (MCI) and mild dementia. Real-world application requires comprehensive assessment beyond MMSE scores, considering factors like ARIA risk. This single-center, real-world study aims to evaluate its efficacy in an expanded population, observe biomarker changes, and assess its safety profile in clinical practice.

Methods: We recruited adults aged 40-90 with early AD from the PUMCH Dementia Cohort. A total of 42 patients received lecanemab treatment, of whom 29 completed the 6-month treatment evaluation. Participants had confirmed amyloid and tau pathology and met clinical criteria (CDR ≤ 1, CDR-SB ≤ 8and MMSE ≥ 18). Comprehensive assessments included neuropsychological testing, CSF and plasma biomarkers (Lumipulse G1200), multi-sequence 3T MRI (volumetric and ALPS index analysis), and amyloid/tau PET imaging (Centiloid quantification). All were monitored for adverse reactions. Matched control groups (matched for sex, age, APOE genotype, disease severity, and baseline therapy) were established for comparison of longitudinally changes in cognitive function, daily living ability and structure MRI.

Results: Treatment was effective even for patients with lower MMSE scores but still classified as having mild dementia by CDR. A significant median Centiloid reduction of 30.9 was observed, with a 24.1% amyloid PET negativity rate after six months. While scores on cognitive and functional scales (CDR-SB, ADL) significantly worsened, indicating disease progression, the rate of progression was significantly slower compared to the control group. Structural MRI showed significant volume reduction in multiple brain regions and increased ventricular volume post-treatment, with no statistically significant change in the ALPS value. The rate of brain volume reduction is faster than that in the control group. Plasma biomarker dynamics (Aβ₄₂, GFAP) indicated effective disease-modifying therapy. Greater Centiloid reduction was linked to more brain volume loss, higher baseline Centiloid levels, higher plasma Aβ₄₂ increase and older age of onset. APOE ɛ4 homozygotes showed less Centiloid reduction. A favorable safety profile was observed, with a 7.1% incidence of asymptomatic, mild ARIA.

Conclusions: This study confirms the clinical efficacy, biomarker changes, and safety profile of lecanemab treatment over a 6-month period, demonstrating its positive therapeutic value and a favorable safety profile in the Chinese population with AD.