Similar Datasets
Project description:The heterogeneous etiology of Alzheimer’s disease (AD) challenges therapeutic development. Understanding cell type gene expression specificity and local spatial contributions to different AD etiologies is instrumental to optimize therapeutic strategies for precision medicine. In this study, we compared cell-specific transcriptomes from the frontal cortex of carriers with the autosomal dominant mutation, PSEN1-E280A, Sporadic AD and Controls. Among the pathways that distinguished the autosomal dominant AD mutation disease from sporadic AD was increased autophagy and proteostasis pathways in astrocytes and oligodendrocytes in the former. Synaptic genes associated with neurofibrillary tangles in excitatory neurons were increased in both sporadic AD and mutation carriers. Spatial transcriptomics in samples from frontal cortex and CA1 hippocampus in PSEN1-E280A cases compared to non-diseased control individuals further validated the activation of chaperone-mediated autophagy genes and NFT-associated genes in E280A cases compared to controls. In conclusion, although autosomal dominant Alzheimer’s disease (ADAD) and sporadic AD share many features, the uniqueness of the cellular responses in each condition must be taken into consideration when designing clinical studies and therapeutics.
2024-02-28 | GSE222494 | GEO
Project description:The heterogeneous etiology of Alzheimer’s disease (AD) challenges therapeutic development. Understanding cell type specificity and local spatial contributions to different AD etiologies is instrumental to optimize therapeutic strategies for precision medicine. In this study, we compared cell-specific transcriptomes from the frontal cortex of carriers with the autosomal dominant mutation, PSEN1-E280A, sporadic AD and controls. Among the pathways that distinguished the autosomal dominant AD mutation disease from sporadic AD was increased autophagy and proteostasis pathways in astrocytes and oligodendrocytes in the former. Synaptic genes associated with neurofibrillary tangles in excitatory neurons were increased in both sporadic AD and mutation carriers. Spatial transcriptomics in samples from frontal cortex and CA1 hippocampus in PSEN1-E280A cases compared to non-diseased control individuals further validated the activation of chaperone-mediated autophagy genes and NFT-associated genes in E280A cases compared to controls. In conclusion, although autosomal dominant Alzheimer’s disease (ADAD) and sporadic AD share many features, the uniqueness of the cellular responses in each condition must be taken into consideration when designing clinical studies and therapeutics.
2024-02-28 | GSE221365 | GEO
Project description:Single Nucleus RNA Sequencing Distinguishes an Autosomal Dominant Form of Alzheimer´s Disease from Sporadic Disease
| PRJNA922204 | ENA
Project description:Genetic studies of Alzheimer disease (AD) have prioritized variants in genes related to the amyloid cascade, lipid metabolism, and neuroimmune modulation. However, the cell-specific effect of variants in these genes is not fully understood. Here, we perform single-nucleus RNA-sequencing (snRNA-seq) on nearly 300,000 nuclei from the parietal cortex of AD autosomal dominant (APP and PSEN1) and risk-modifying variant (APOE, TREM2 and MS4A) carriers. Within individual cell types, we capture genes commonly dysregulated across variant groups. However, specific transcriptional states are more prevalent within variant carriers. TREM2 oligodendrocytes show a dysregulated autophagy-lysosomal pathway, MS4A microglia have dysregulated complement cascade genes, and APOEε4 inhibitory neurons display signs of ferroptosis. All cell types have enriched states in autosomal dominant carriers. We leverage differential expression and single-nucleus ATAC-seq to map GWAS signals to effector cell types including the NCK2 signal to neurons in addition to the initially proposed microglia. Overall, our results provide insights into the transcriptional diversity resulting from AD genetic architecture and cellular heterogeneity. The data can be explored on the online browser ( http://web.hararilab.org/SNARE/ ).
| S-EPMC10121712 | biostudies-literature
Project description:Single Nucleus RNA Sequencing Distinguishes an Autosomal Dominant Form of Alzheimer´s Disease from Sporadic Disease [spatial transcriptomics]
| PRJNA913963 | ENA
Project description:Single Nucleus RNA Sequencing Distinguishes an Autosomal Dominant Form of Alzheimer´s Disease from Sporadic Disease [snRNA-seq]
| PRJNA922210 | ENA
Project description:Autosomal-dominant Alzheimer disease (ADAD) is a genetic disorder caused by mutations in Amyloid Precursor Protein (APP) or Presenilin (PSEN) genes. Studies from families with ADAD have been critical to support the amyloid cascade hypothesis of Alzheimer disease (AD), the basis for the current development of amyloid-based disease-modifying therapies in sporadic AD (SAD). However, whether the pathological changes in APP processing in the CNS in ADAD are similar to those observed in SAD remains unclear. In this study, we measured β-site APP-cleaving enzyme (BACE) protein levels and activity, APP and APP C-terminal fragments in brain samples from subjects with ADAD carrying APP or PSEN1 mutations (n = 18), patients with SAD (n = 27) and age-matched controls (n = 22). We also measured sAPPβ and BACE protein levels, as well as BACE activity, in CSF from individuals carrying PSEN1 mutations (10 mutation carriers and 7 non-carrier controls), patients with SAD (n = 32) and age-matched controls (n = 11). We found that in the brain, the pattern in ADAD was characterized by an increase in APP β-C-terminal fragment (β-CTF) levels despite no changes in BACE protein levels or activity. In contrast, the pattern in SAD in the brain was mainly characterized by an increase in BACE levels and activity, with less APP β-CTF accumulation than ADAD. In the CSF, no differences were found between groups in BACE activity or expression or sAPPβ levels. Taken together, these data suggest that the physiopathological events underlying the chronic Aβ production/clearance imbalance in SAD and ADAD are different. These differences should be considered in the design of intervention trials in AD.
| S-EPMC3623032 | biostudies-literature
Project description:1H magnetic resonance spectroscopy (MRS) can reveal changes in brain biochemistry in vivo in humans and has been applied to late onset Alzheimer disease (AD). Carriers of mutations for autosomal dominant Alzheimer disease (ADAD) may show changes in levels of metabolites prior to the onset of clinical symptoms. Proton MR spectra were acquired at 1.5 T for 16 cognitively asymptomatic or mildly symptomatic mutation carriers (CDR?<?1) and 11 non-carriers as part of a comprehensive cross-sectional study of preclinical ADAD. Levels of N-acetyl-aspartate+N-acetyl-aspartyl-glutamate (NAA), glutamate/glutamine (Glx), creatine/phosphocreate (Cr), choline (Cho), and myo-inositol (mI) in the left and right anterior cingulate and midline posterior cingulate and precuneus were compared between mutation carriers (MCs) and non-carriers (NCs) using multivariate analysis of variance with age as a covariate. Among MCs, correlations between metabolite levels and time until expected age of dementia diagnosis were calculated. MCs had significantly lower levels of NAA and Glx in the left pregenual anterior cingulate cortex, and lower levels of NAA and higher levels of mI and Cho in the precuneus compared to NCs. Increased levels of mI were seen in these regions in association with increased proximity to expected age of dementia onset. MRS shows effects of ADAD similar to those seen in late onset AD even during the preclinical period including lower levels of NAA and higher levels of mI. These indices of neuronal and glial dysfunction might serve as surrogate outcome measures in prevention studies of putative disease-modifying agents.
| S-EPMC6295351 | biostudies-literature
Project description:OBJECTIVE:To study the macrostructural and microstructural MRI correlates of brain astrocytosis, measured with 11C-deuterium-L-deprenyl (11C-DED)-PET, in familial autosomal-dominant Alzheimer disease (ADAD). METHODS:The total sample (n = 31) comprised ADAD mutation carriers (n = 10 presymptomatic, 39.2 ± 10.6 years old; n = 3 symptomatic, 55.5 ± 2.0 years old) and noncarriers (n = 18, 44.0 ± 13.7 years old) belonging to families with mutations in either the presenilin-1 or amyloid precursor protein genes. All participants underwent structural and diffusion MRI and neuropsychological assessment, and 20 participants (6 presymptomatic and 3 symptomatic mutation carriers and 11 noncarriers) also underwent 11C-DED-PET. RESULTS:Vertex-wise interaction analyses revealed a differential relationship between carriers and noncarriers in the association between 11C-DED binding and estimated years to onset (EYO) and between cortical mean diffusivity (MD) and EYO. These differences were due to higher 11C-DED binding in presymptomatic carriers, with lower binding in symptomatic carriers compared to noncarriers, and to lower cortical MD in presymptomatic carriers, with higher MD in symptomatic carriers compared to noncarriers. Using a vertex-wise local correlation approach, 11C-DED binding was negatively correlated with cortical MD and positively correlated with cortical thickness. CONCLUSIONS:Our proof-of-concept study is the first to show that microstructural and macrostructural changes can reflect underlying neuroinflammatory mechanisms in early stages of Alzheimer disease (AD). The findings support a role for neuroinflammation in AD pathogenesis, with potential implications for the correct interpretation of neuroimaging biomarkers as surrogate endpoints in clinical trials.
| S-EPMC7282881 | biostudies-literature
Project description:ObjectiveTo investigate default mode network (DMN) functional connectivity MRI (fcMRI) in a large cross-sectional cohort of subjects from families harboring pathogenic presenilin-1 (PSEN1), presenilin-2 (PSEN2), and amyloid precursor protein (APP) mutations participating in the Dominantly Inherited Alzheimer Network.MethodsEighty-three mutation carriers and 37 asymptomatic noncarriers from the same families underwent fMRI during resting state at 8 centers in the United States, United Kingdom, and Australia. Using group-independent component analysis, fcMRI was compared using mutation status and Clinical Dementia Rating to stratify groups, and related to each participant's estimated years from expected symptom onset (eYO).ResultsWe observed significantly decreased DMN fcMRI in mutation carriers with increasing Clinical Dementia Rating, most evident in the precuneus/posterior cingulate and parietal cortices (p < 0.001). Comparison of asymptomatic mutation carriers with noncarriers demonstrated decreased fcMRI in the precuneus/posterior cingulate (p = 0.014) and right parietal cortex (p = 0.0016). We observed a significant interaction between mutation carrier status and eYO, with decreases in DMN fcMRI observed as mutation carriers approached and surpassed their eYO.ConclusionFunctional disruption of the DMN occurs early in the course of autosomal dominant Alzheimer disease, beginning before clinically evident symptoms, and worsening with increased impairment. These findings suggest that DMN fcMRI may prove useful as a biomarker across a wide spectrum of disease, and support the feasibility of DMN fcMRI as a secondary endpoint in upcoming multicenter clinical trials in Alzheimer disease.
| S-EPMC3776464 | biostudies-literature