Publications by authors named "Nilüfer Ertekin-Taner"

126 Publications

Microglia show differential transcriptomic response to Aβ peptide aggregates ex vivo and in vivo.

Life Sci Alliance 2021 07 14;4(7). Epub 2021 Jun 14.

Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, USA

Aggregation and accumulation of amyloid-β (Aβ) is a defining feature of Alzheimer's disease pathology. To study microglial responses to Aβ, we applied exogenous Aβ peptide, in either oligomeric or fibrillar conformation, to primary mouse microglial cultures and evaluated system-level transcriptional changes and then compared these with transcriptomic changes in the brains of CRND8 APP mice. We find that primary microglial cultures have rapid and massive transcriptional change in response to Aβ. Transcriptomic responses to oligomeric or fibrillar Aβ in primary microglia, although partially overlapping, are distinct and are not recapitulated in vivo where Aβ progressively accumulates. Furthermore, although classic immune mediators show massive transcriptional changes in the primary microglial cultures, these changes are not observed in the mouse model. Together, these data extend previous studies which demonstrate that microglia responses ex vivo are poor proxies for in vivo responses. Finally, these data demonstrate the potential utility of using microglia as biosensors of different aggregate conformation, as the transcriptional responses to oligomeric and fibrillar Aβ can be distinguished.
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http://dx.doi.org/10.26508/lsa.202101108DOI Listing
July 2021

A molecular pathology, neurobiology, biochemical, genetic and neuroimaging study of progressive apraxia of speech.

Nat Commun 2021 06 8;12(1):3452. Epub 2021 Jun 8.

Department of Radiology, Mayo Clinic, Rochester, MN, USA.

Progressive apraxia of speech is a neurodegenerative syndrome affecting spoken communication. Molecular pathology, biochemistry, genetics, and longitudinal imaging were investigated in 32 autopsy-confirmed patients with progressive apraxia of speech who were followed over 10 years. Corticobasal degeneration and progressive supranuclear palsy (4R-tauopathies) were the most common underlying pathologies. Perceptually distinct speech characteristics, combined with age-at-onset, predicted specific 4R-tauopathy; phonetic subtype and younger age predicted corticobasal degeneration, and prosodic subtype and older age predicted progressive supranuclear palsy. Phonetic and prosodic subtypes showed differing relationships within the cortico-striato-pallido-nigro-luysial network. Biochemical analysis revealed no distinct differences in aggregated 4R-tau while tau H1 haplotype frequency (69%) was lower compared to 1000+ autopsy-confirmed 4R-tauopathies. Corticobasal degeneration patients had faster rates of decline, greater cortical degeneration, and shorter illness duration than progressive supranuclear palsy. These findings help define the pathobiology of progressive apraxia of speech and may have consequences for development of 4R-tau targeting treatment.
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http://dx.doi.org/10.1038/s41467-021-23687-8DOI Listing
June 2021

Clinical, Imaging, and Pathologic Characteristics of Patients With Right Versus Left Hemisphere-Predominant Logopenic Progressive Aphasia.

Neurology 2021 Jun 4. Epub 2021 Jun 4.

Department of Neurology, Rochester, MN, USA

Objective: To assess and compare demographic, clinical, neuroimaging and pathologic characteristics of a cohort of patients with right versus left hemisphere-predominant logopenic progressive aphasia (LPA).

Methods: This is a case-control study of patients with LPA who were prospectively followed at Mayo Clinic and underwent an [F]-fluorodeoxyglucose (FDG)-PET scan. Patients were classified as rLPA if right temporal lobe metabolism was ≥1 standard deviation lower than left temporal lobe metabolism. Patients with rLPA were frequency-matched 3:1 to typical left-predominant LPA based on degree of asymmetry and severity of temporal lobe metabolism. Patients were compared on clinical, imaging (MRI, FDG-PET, amyloid-beta- and tau-PET) and pathologic characteristics.

Results: Of 103 prospectively recruited LPA patients 8 (4 females) were classified as rLPA (7.8%); all rLPA cases were right-handed. rLPA patients had milder aphasia based on the Western Aphasia Battery-Aphasia Quotient (=0.04) and less frequent phonologic errors (=0.015). rLPA had shorter survival compared to typical LPA: hazard ratio 4.0(1.2- 12.9), =0.02. There were no other differences in demographics, handedness, genetics, neurological or neuropsychological tests. Compared to the 24 frequency-matched typical LPA patients, rLPA showed greater frontotemporal hypometabolism of the non-dominant hemisphere on FDG-PET and less atrophy in amygdala and hippocampus of the dominant hemisphere. Autopsy evaluation revealed a similar distribution of pathologic findings in both groups, with Alzheimer's disease pathologic changes being the most frequent pathology.

Conclusions: Right LPA is associated with less severe aphasia but has shorter survival from reported symptom onset than typical LPA, possibly related to greater involvement of the non-dominant hemisphere.
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http://dx.doi.org/10.1212/WNL.0000000000012322DOI Listing
June 2021

Genome-wide analysis identifies a novel LINC-PINT splice variant associated with vascular amyloid pathology in Alzheimer's disease.

Acta Neuropathol Commun 2021 05 21;9(1):93. Epub 2021 May 21.

Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA.

Cerebral amyloid angiopathy (CAA) contributes to accelerated cognitive decline in Alzheimer's disease (AD) dementia and is a common finding at autopsy. The APOEε4 allele and male sex have previously been reported to associate with increased CAA in AD. To inform biomarker and therapeutic target discovery, we aimed to identify additional genetic risk factors and biological pathways involved in this vascular component of AD etiology. We present a genome-wide association study of CAA pathology in AD cases and report sex- and APOE-stratified assessment of this phenotype. Genome-wide genotypes were collected from 853 neuropathology-confirmed AD cases scored for CAA across five brain regions, and imputed to the Haplotype Reference Consortium panel. Key variables and genome-wide genotypes were tested for association with CAA in all individuals and in sex and APOEε4 stratified subsets. Pathway enrichment was run for each of the genetic analyses. Implicated loci were further investigated for functional consequences using brain transcriptome data from 1,186 samples representing seven brain regions profiled as part of the AMP-AD consortium. We confirmed association of male sex, AD neuropathology and APOEε4 with increased CAA, and identified a novel locus, LINC-PINT, associated with lower CAA amongst APOEε4-negative individuals (rs10234094-C, beta = -3.70 [95% CI -0.49--0.24]; p = 1.63E-08). Transcriptome profiling revealed higher LINC-PINT expression levels in AD cases, and association of rs10234094-C with altered LINC-PINT splicing. Pathway analysis indicates variation in genes involved in neuronal health and function are linked to CAA in AD patients. Further studies in additional and diverse cohorts are needed to assess broader translation of our findings.
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http://dx.doi.org/10.1186/s40478-021-01199-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8147512PMC
May 2021

Modulating innate immune activation states impacts the efficacy of specific Aβ immunotherapy.

Mol Neurodegener 2021 May 6;16(1):32. Epub 2021 May 6.

Department of Neuroscience and Neurology, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, University of Florida, FL, 32611, Gainesville, USA.

Introduction: Passive immunotherapies targeting Aβ continue to be evaluated as Alzheimer's disease (AD) therapeutics, but there remains debate over the mechanisms by which these immunotherapies work. Besides the amount of preexisting Aβ deposition and the type of deposit (compact or diffuse), there is little data concerning what factors, independent of those intrinsic to the antibody, might influence efficacy. Here we (i) explored how constitutive priming of the underlying innate activation states by Il10 and Il6 might influence passive Aβ immunotherapy and (ii) evaluated transcriptomic data generated in the AMP-AD initiative to inform how these two cytokines and their receptors' mRNA levels are altered in human AD and an APP mouse model.

Methods: rAAV2/1 encoding EGFP, Il6 or Il10 were delivered by somatic brain transgenesis to neonatal (P0) TgCRND8 APP mice. Then, at 2 months of age, the mice were treated bi-weekly with a high-affinity anti-Aβ1-16 mAb5 monoclonal antibody or control mouse IgG until 6 months of age. rAAV mediated transgene expression, amyloid accumulation, Aβ levels and gliosis were assessed. Extensive transcriptomic data was used to evaluate the mRNA expression levels of IL10 and IL6 and their receptors in the postmortem human AD temporal cortex and in the brains of TgCRND8 mice, the later at multiple ages.

Results: Priming TgCRND8 mice with Il10 increases Aβ loads and blocks efficacy of subsequent mAb5 passive immunotherapy, whereas priming with Il6 priming reduces Aβ loads by itself and subsequent Aβ immunotherapy shows only a slightly additive effect. Transcriptomic data shows that (i) there are significant increases in the mRNA levels of Il6 and Il10 receptors in the TgCRND8 mouse model and temporal cortex of humans with AD and (ii) there is a great deal of variance in individual mouse brain and the human temporal cortex of these interleukins and their receptors.

Conclusions: The underlying immune activation state can markedly affect the efficacy of passive Aβ immunotherapy. These results have important implications for ongoing human AD immunotherapy trials, as they indicate that underlying immune activation states within the brain, which may be highly variable, may influence the ability for passive immunotherapy to alter Aβ deposition.
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http://dx.doi.org/10.1186/s13024-021-00453-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8103631PMC
May 2021

Transcriptomic analysis to identify genes associated with selective hippocampal vulnerability in Alzheimer's disease.

Nat Commun 2021 04 19;12(1):2311. Epub 2021 Apr 19.

Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA.

Selective vulnerability of different brain regions is seen in many neurodegenerative disorders. The hippocampus and cortex are selectively vulnerable in Alzheimer's disease (AD), however the degree of involvement of the different brain regions differs among patients. We classified corticolimbic patterns of neurofibrillary tangles in postmortem tissue to capture extreme and representative phenotypes. We combined bulk RNA sequencing with digital pathology to examine hippocampal vulnerability in AD. We identified hippocampal gene expression changes associated with hippocampal vulnerability and used machine learning to identify genes that were associated with AD neuropathology, including SERPINA5, RYBP, SLC38A2, FEM1B, and PYDC1. Further histologic and biochemical analyses suggested SERPINA5 expression is associated with tau expression in the brain. Our study highlights the importance of embracing heterogeneity of the human brain in disease to identify disease-relevant gene expression.
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http://dx.doi.org/10.1038/s41467-021-22399-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8055900PMC
April 2021

Impact of variant-level batch effects on identification of genetic risk factors in large sequencing studies.

PLoS One 2021 16;16(4):e0249305. Epub 2021 Apr 16.

Division of Computational Biology, Department of Quantitative Health Sciences, Mayo Clinic, Jacksonville, Florida, United States of America.

Genetic studies have shifted to sequencing-based rare variants discovery after decades of success in identifying common disease variants by Genome-Wide Association Studies using Single Nucleotide Polymorphism chips. Sequencing-based studies require large sample sizes for statistical power and therefore often inadvertently introduce batch effects because samples are typically collected, processed, and sequenced at multiple centers. Conventionally, batch effects are first detected and visualized using Principal Components Analysis and then controlled by including batch covariates in the disease association models. For sequencing-based genetic studies, because all variants included in the association analyses have passed sequencing-related quality control measures, this conventional approach treats every variant as equal and ignores the substantial differences still remaining in variant qualities and characteristics such as genotype quality scores, alternative allele fractions (fraction of reads supporting alternative allele at a variant position) and sequencing depths. In the Alzheimer's Disease Sequencing Project (ADSP) exome dataset of 9,904 cases and controls, we discovered hidden variant-level differences between sample batches of three sequencing centers and two exome capture kits. Although sequencing centers were included as a covariate in our association models, we observed differences at the variant level in genotype quality and alternative allele fraction between samples processed by different exome capture kits that significantly impacted both the confidence of variant detection and the identification of disease-associated variants. Furthermore, we found that a subset of top disease-risk variants came exclusively from samples processed by one exome capture kit that was more effective at capturing the alternative alleles compared to the other kit. Our findings highlight the importance of additional variant-level quality control for large sequencing-based genetic studies. More importantly, we demonstrate that automatically filtering out variants with batch differences may lead to false negatives if the batch discordances come largely from quality differences and if the batch-specific variants have better quality.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0249305PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8051815PMC
April 2021

Analysis of intraoperative human brain tissue transcriptome reveals putative risk genes and altered molecular pathways in glioma-related seizures.

Epilepsy Res 2021 Jul 18;173:106618. Epub 2021 Mar 18.

Department of Neurosurgery, Mayo Clinic, Jacksonville, FL, USA. Electronic address:

Background: The pathogenesis of glioma-related seizures (GRS) is poorly understood. Here in, we aim to identify putative molecular pathways that lead to the development of GRS.

Methods: We determined brain transcriptome from intraoperative human brain tissue of patients with either GRS, glioma without seizures (non-GRS), or with idiopathic temporal lobe epilepsy (iTLE). We performed transcriptome-wide comparisons between disease groups tissue from non-epileptic controls (non-EC) to identify differentially-expressed genes (DEG). We compared DEGs to identify those that are specific or common to the groups. Through a gene ontology analysis, we identified molecular pathways enriched for genes with a Log-fold change ≥1.5 or ≤-1.5 and p-value <0.05 compared to non-EC.

Results: We identified 110 DEGs that are associated with GRS vs. non-GRS: 80 genes showed high and 30 low expression in GRS. There was significant overexpression of genes involved in cell-to-cell and glutamatergic signaling (CELF4, SLC17A7, and CAMK2A) and down-regulation of genes involved immune-trafficking (CXCL8, H19, and VEGFA). In the iTLE vs GRS analysis, there were 1098 DEGs: 786 genes were overexpressed and 312 genes were underexpressed in the GRS samples. There was significant enrichment for genes considered markers of oncogenesis (GSC, MYBL2, and TOP2A). Further, there was down-regulation of genes involved in the glutamatergic neurotransmission (vesicular glutamate transporter-2) in the GRS vs. iTLE samples.

Conclusions: We identified a number of altered processes such as cell-to-cell signaling and interaction, inflammation-related, and glutamatergic neurotransmission in the pathogenesis of GRS. Our findings offer a new landscape of targets to further study in the fields of brain tumors and seizures.
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http://dx.doi.org/10.1016/j.eplepsyres.2021.106618DOI Listing
July 2021

Expression of an alternatively spliced variant of SORL1 in neuronal dendrites is decreased in patients with Alzheimer's disease.

Acta Neuropathol Commun 2021 03 16;9(1):43. Epub 2021 Mar 16.

Department of Biomedicine, Aarhus University, Høegh-Guldbergs Gade 10, 8000, Aarhus C, Denmark.

SORL1 is strongly associated with both sporadic and familial forms of Alzheimer's disease (AD), but a lack of information about alternatively spliced transcripts currently limits our understanding of the role of SORL1 in AD. Here, we describe a SORL1 transcript (SORL1-38b) characterized by inclusion of a novel exon (E38b) that encodes a truncated protein. We identified E38b-containing transcripts in several brain regions, with the highest expression in the cerebellum and showed that SORL1-38b is largely located in neuronal dendrites, which is in contrast to the somatic distribution of transcripts encoding the full-length SORLA protein (SORL1-fl). SORL1-38b transcript levels were significantly reduced in AD cerebellum in three independent cohorts of postmortem brains, whereas no changes were observed for SORL1-fl. A trend of lower 38b transcript level in cerebellum was found for individuals carrying the risk variant at rs2282649 (known as SNP24), although not reaching statistical significance. These findings suggest synaptic functions for SORL1-38b in the brain, uncovering novel aspects of SORL1 that can be further explored in AD research.
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http://dx.doi.org/10.1186/s40478-021-01140-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7962264PMC
March 2021

Latent trait modeling of tau neuropathology in progressive supranuclear palsy.

Acta Neuropathol 2021 05 26;141(5):667-680. Epub 2021 Feb 26.

Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA.

Progressive supranuclear palsy (PSP) is the second most common neurodegenerative Parkinsonian disorder after Parkinson's disease, and is characterized as a primary tauopathy. Leveraging the considerable clinical and neuropathologic heterogeneity associated with PSP, we measured tau neuropathology as quantitative traits to perform a genome-wide association study (GWAS) within PSP to identify genes and biological pathways that underlie the PSP disease process. In 882 PSP cases, semi-quantitative scores for phosphorylated tau-immunoreactive coiled bodies (CBs), neurofibrillary tangles (NFTs), tufted astrocytes (TAs), and tau threads were documented from 18 brain regions, and converted to latent trait (LT) variables using the R ltm package. LT analysis utilizes a multivariate regression model that links categorical responses to unobserved covariates allowing for a reduction of dimensionality, generating a single, continuous variable to account for the multiple lesions and brain regions assessed. We first tested for association with PSP LTs and the top PSP GWAS susceptibility loci. Significant SNP/LT associations were identified at rs242557 (MAPT H1c sub-haplotype) with hindbrain CBs and rs1768208 (MOBP) with forebrain tau threads. Digital microscopy was employed to quantify phosphorylated tau burden in midbrain tectum and red nucleus in 795 PSP cases and tau burdens were used as quantitative phenotypes in GWAS. Top associations were identified at rs1768208 with midbrain tectum and red nucleus tau burden. Additionally, we performed a PSP LT GWAS on an initial cohort, a follow-up SNP panel (37 SNPs, P < 10) in an extended cohort, and a combined analysis. Top SNP/LT associations were identified at SNPs in or near SPTBN5/EHD4, SEC13/ATP2B2, EPHB1/PPP2R3A, TBC1D8, IFNGR1/OLIG3, ST6GAL1, HK1, CALB1, and SGCZ. Finally, testing for SNP/transcript associations using whole transcriptome and whole genome data identified significant expression quantitative trait loci at rs3088159/SPTBN5/EHD4 and rs154239/GHRL. Modeling tau neuropathology heterogeneity using LTs as quantitative phenotypes in a GWAS may provide substantial insight into biological pathways involved in PSP by affecting regional tau burden.
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http://dx.doi.org/10.1007/s00401-021-02289-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8043857PMC
May 2021

Integrative functional genomic analysis of intron retention in human and mouse brain with Alzheimer's disease.

Alzheimers Dement 2021 Jun 21;17(6):984-1004. Epub 2021 Jan 21.

Institute for Systems Biology, Seattle, Washington, USA.

Intron retention (IR) has been implicated in the pathogenesis of complex diseases such as cancers; its association with Alzheimer's disease (AD) remains unexplored. We performed genome-wide analysis of IR through integrating genetic, transcriptomic, and proteomic data of AD subjects and mouse models from the Accelerating Medicines Partnership-Alzheimer's Disease project. We identified 4535 and 4086 IR events in 2173 human and 1736 mouse genes, respectively. Quantitation of IR enabled the identification of differentially expressed genes that conventional exon-level approaches did not reveal. There were significant correlations of intron expression within innate immune genes, like HMBOX1, with AD in humans. Peptides with a high probability of translation from intron-retained mRNAs were identified using mass spectrometry. Further, we established AD-specific intron expression Quantitative Trait Loci, and identified splicing-related genes that may regulate IR. Our analysis provides a novel resource for the search for new AD biomarkers and pathological mechanisms.
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http://dx.doi.org/10.1002/alz.12254DOI Listing
June 2021

Identifying drug targets for neurological and psychiatric disease via genetics and the brain transcriptome.

PLoS Genet 2021 01 8;17(1):e1009224. Epub 2021 Jan 8.

MRC Integrative Epidemiology Unit (IEU), Population Health Sciences, University of Bristol, Bristol, United Kingdom.

Discovering drugs that efficiently treat brain diseases has been challenging. Genetic variants that modulate the expression of potential drug targets can be utilized to assess the efficacy of therapeutic interventions. We therefore employed Mendelian Randomization (MR) on gene expression measured in brain tissue to identify drug targets involved in neurological and psychiatric diseases. We conducted a two-sample MR using cis-acting brain-derived expression quantitative trait loci (eQTLs) from the Accelerating Medicines Partnership for Alzheimer's Disease consortium (AMP-AD) and the CommonMind Consortium (CMC) meta-analysis study (n = 1,286) as genetic instruments to predict the effects of 7,137 genes on 12 neurological and psychiatric disorders. We conducted Bayesian colocalization analysis on the top MR findings (using P<6x10-7 as evidence threshold, Bonferroni-corrected for 80,557 MR tests) to confirm sharing of the same causal variants between gene expression and trait in each genomic region. We then intersected the colocalized genes with known monogenic disease genes recorded in Online Mendelian Inheritance in Man (OMIM) and with genes annotated as drug targets in the Open Targets platform to identify promising drug targets. 80 eQTLs showed MR evidence of a causal effect, from which we prioritised 47 genes based on colocalization with the trait. We causally linked the expression of 23 genes with schizophrenia and a single gene each with anorexia, bipolar disorder and major depressive disorder within the psychiatric diseases and 9 genes with Alzheimer's disease, 6 genes with Parkinson's disease, 4 genes with multiple sclerosis and two genes with amyotrophic lateral sclerosis within the neurological diseases we tested. From these we identified five genes (ACE, GPNMB, KCNQ5, RERE and SUOX) as attractive drug targets that may warrant follow-up in functional studies and clinical trials, demonstrating the value of this study design for discovering drug targets in neuropsychiatric diseases.
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http://dx.doi.org/10.1371/journal.pgen.1009224DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7819609PMC
January 2021

Cilostazol Versus Aspirin for Secondary Stroke Prevention: Systematic Review and Meta-Analysis.

J Stroke Cerebrovasc Dis 2021 Mar 31;30(3):105581. Epub 2020 Dec 31.

Department of Neurology, Mayo Clinic, Jacksonville, FL, United States.

Objectives: Cilostazol has promise as an alternative to aspirin for secondary stroke prevention given its vasodilatory and anti-inflammatory properties in addition to platelet aggregation inhibition. We aimed to conduct a systematic review and meta-analysis to estimate the efficacy and safety of cilostazol compared to aspirin for stroke prevention in patients with previous stroke or transient ischemic attack (TIA).

Materials And Methods: We searched PubMed and the Cochrane Central Register of Controlled Trials from 1996 to 2019. Randomized clinical trials that compared cilostazol to aspirin and reported the endpoints of ischemic stroke, intracranial hemorrhage and any bleeding were included. A random-effects estimate was computed based on the Mantel-Haenszel method. The pooled risk estimates with 95% confidence intervals were compared between cilostazol and aspirin.

Results: The search identified 5 randomized clinical trials comparing cilostazol vs. aspirin for secondary stroke prevention that collectively enrolled 7240 patients, all from Asian countries (3615 received cilostazol and 3625 received aspirin). Pooled results from the random-effects model showed that cilostazol was associated with significantly lower risk of recurrent ischemic stroke (RR 0.68; 95% CI, 0.54 to 0.87), intracranial hemorrhage (RR 0.42; 95% CI, 0.27 to 0.65) and any bleeding (RR 0.71; 95% CI, 0.55 to 0.91).

Conclusions: This meta-analysis suggests that cilostazol is more effective than aspirin in preventing recurrent ischemic stroke with lower risk of intracranial hemorrhage and other bleeding. Since all trials to date are from Asian countries, confirmatory trials of cilostazol for secondary stroke prevention in other populations are needed.
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http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2020.105581DOI Listing
March 2021

Comparative evaluation for the globin gene depletion methods for mRNA sequencing using the whole blood-derived total RNAs.

BMC Genomics 2020 Dec 11;21(1):890. Epub 2020 Dec 11.

Medical Genome Facility, Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA.

Background: There are challenges in generating mRNA-Seq data from whole-blood derived RNA as globin gene and rRNA are frequent contaminants. Given the abundance of erythrocytes in whole blood, globin genes comprise some 80% or more of the total RNA. Therefore, depletion of globin gene RNA and rRNA are critical steps required to have adequate coverage of reads mapping to the reference transcripts and thus reduce the total cost of sequencing. In this study, we directly compared the performance of probe hybridization (GLOBINClear Kit and Globin-Zero Gold rRNA Removal Kit) and RNAse-H enzymatic depletion (NEBNext® Globin & rRNA Depletion Kit and Ribo-Zero Plus rRNA Depletion Kit) methods from 1 μg of whole blood-derived RNA on mRNA-Seq profiling. All RNA samples were treated with DNaseI for additional cleanup before the depletion step and were processed for poly-A selection for library generation.

Results: Probe hybridization revealed a better overall performance than the RNAse-H enzymatic depletion method, detecting a higher number of genes and transcripts without 3' region bias. After depletion, samples treated with probe hybridization showed globin genes at 0.5% (±0.6%) of the total mapped reads; the RNAse-H enzymatic depletion had 3.2% (±3.8%). Probe hybridization showed more junction reads and transcripts compared with RNAse-H enzymatic depletion and also had a higher correlation (R > 0.9) than RNAse-H enzymatic depletion (R > 0.85).

Conclusion: In this study, our results showed that 1 μg of high-quality RNA from whole blood could be routinely used for transcriptional profiling analysis studies with globin gene and rRNA depletion pre-processing. We also demonstrated that the probe hybridization depletion method is better suited to mRNA sequencing analysis with minimal effect on RNA quality during depletion procedures.
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http://dx.doi.org/10.1186/s12864-020-07304-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7733259PMC
December 2020

Plasma Biomarkers of Alzheimer's Disease in African Americans.

J Alzheimers Dis 2021 ;79(1):323-334

Mayo Clinic, Department of Neuroscience, Jacksonville, FL, USA.

Background/objective: The aim of this study was to determine if plasma concentrations of 5 surrogate markers of Alzheimer's disease (AD) pathology and neuroinflammation are associated with disease status in African Americans.

Methods: We evaluated 321 African Americans (159 AD, 162 controls) from the Florida Consortium for African-American Alzheimer's Disease Studies (FCA3DS). Five plasma proteins reflecting AD neuropathology or inflammation (Aβ42, tau, IL6, IL10, TNFα) were tested for associations with AD, age, sex, APOE and MAPT genotypes, and for pairwise correlations.

Results: Plasma tau levels were higher in AD when adjusted for biological and technical covariates. APOEɛ4 was associated with lower plasma Aβ42 and tau levels. Older age was associated with higher plasma Aβ42, tau, and TNFα. Females had lower IL10 levels. Inflammatory proteins had strong pairwise correlations amongst themselves and with Aβ42.

Conclusion: We identified effects of demographic and genetic variants on five potential plasma biomarkers in African Americans. Plasma inflammatory biomarkers and Aβ42 may reflect correlated pathologies and elevated plasma tau may be a biomarker of AD in this population.
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http://dx.doi.org/10.3233/JAD-200828DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7902984PMC
January 2021

Utility of Plasma Neurofilament Light in the 1Florida Alzheimer's Disease Research Center (ADRC).

J Alzheimers Dis 2021 ;79(1):59-70

Wien Center for Alzheimer's Disease and Memory Disorder, Mount Sinai Medical Center, Miami Beach, FL, USA.

Background: Plasma NfL (pNfL) levels are elevated in many neurological disorders. However, the utility of pNfL in a clinical setting has not been established.

Objective: In a cohort of diverse older participants, we examined: 1) the association of pNfL to age, sex, Hispanic ethnicity, diagnosis, and structural and amyloid imaging biomarkers; and 2) its association to baseline and longitudinal cognitive and functional performance.

Methods: 309 subjects were classified at baseline as cognitively normal (CN) or with cognitive impairment. Most subjects had structural MRI and amyloid PET scans. The most frequent etiological diagnosis was Alzheimer's disease (AD), but other neurological and neuropsychiatric disorders were also represented. We assessed the relationship of pNfL to cognitive and functional status, primary etiology, imaging biomarkers, and to cognitive and functional decline.

Results: pNfL increased with age, degree of hippocampal atrophy, and amyloid load, and was higher in females among CN subjects, but was not associated with Hispanic ethnicity. Compared to CN subjects, pNfL was elevated among those with AD or FTLD, but not those with neuropsychiatric or other disorders. Hippocampal atrophy, amyloid positivity and higher pNfL levels each added unique variance in predicting greater functional impairment on the CDR-SB at baseline. Higher baseline pNfL levels also predicted greater cognitive and functional decline after accounting for hippocampal atrophy and memory scores at baseline.

Conclusion: pNfL may have a complementary and supportive role to brain imaging and cognitive testing in a memory disorder evaluation, although its diagnostic sensitivity and specificity as a stand-alone measure is modest. In the absence of expensive neuroimaging tests, pNfL could be used for differentiating neurodegenerative disease from neuropsychiatric disorders.
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http://dx.doi.org/10.3233/JAD-200901DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7902971PMC
January 2021

Molecular estimation of neurodegeneration pseudotime in older brains.

Nat Commun 2020 11 13;11(1):5781. Epub 2020 Nov 13.

Sage Bionetworks, Seattle, WA, USA.

The temporal molecular changes that lead to disease onset and progression in Alzheimer's disease (AD) are still unknown. Here we develop a temporal model for these unobserved molecular changes with a manifold learning method applied to RNA-Seq data collected from human postmortem brain samples collected within the ROS/MAP and Mayo Clinic RNA-Seq studies. We define an ordering across samples based on their similarity in gene expression and use this ordering to estimate the molecular disease stage-or disease pseudotime-for each sample. Disease pseudotime is strongly concordant with the burden of tau (Braak score, P = 1.0 × 10), Aβ (CERAD score, P = 1.8 × 10), and cognitive diagnosis (P = 3.5 × 10) of late-onset (LO) AD. Early stage disease pseudotime samples are enriched for controls and show changes in basic cellular functions. Late stage disease pseudotime samples are enriched for late stage AD cases and show changes in neuroinflammation and amyloid pathologic processes. We also identify a set of late stage pseudotime samples that are controls and show changes in genes enriched for protein trafficking, splicing, regulation of apoptosis, and prevention of amyloid cleavage pathways. In summary, we present a method for ordering patients along a trajectory of LOAD disease progression from brain transcriptomic data.
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http://dx.doi.org/10.1038/s41467-020-19622-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7666177PMC
November 2020

APOE4 exacerbates synapse loss and neurodegeneration in Alzheimer's disease patient iPSC-derived cerebral organoids.

Nat Commun 2020 11 2;11(1):5540. Epub 2020 Nov 2.

Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA.

APOE4 is the strongest genetic risk factor associated with late-onset Alzheimer's disease (AD). To address the underlying mechanism, we develop cerebral organoid models using induced pluripotent stem cells (iPSCs) with APOE ε3/ε3 or ε4/ε4 genotype from individuals with either normal cognition or AD dementia. Cerebral organoids from AD patients carrying APOE ε4/ε4 show greater apoptosis and decreased synaptic integrity. While AD patient-derived cerebral organoids have increased levels of Aβ and phosphorylated tau compared to healthy subject-derived cerebral organoids, APOE4 exacerbates tau pathology in both healthy subject-derived and AD patient-derived organoids. Transcriptomics analysis by RNA-sequencing reveals that cerebral organoids from AD patients are associated with an enhancement of stress granules and disrupted RNA metabolism. Importantly, isogenic conversion of APOE4 to APOE3 attenuates the APOE4-related phenotypes in cerebral organoids from AD patients. Together, our study using human iPSC-organoids recapitulates APOE4-related phenotypes and suggests APOE4-related degenerative pathways contributing to AD pathogenesis.
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http://dx.doi.org/10.1038/s41467-020-19264-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7608683PMC
November 2020

Association of ABI3 and PLCG2 missense variants with disease risk and neuropathology in Lewy body disease and progressive supranuclear palsy.

Acta Neuropathol Commun 2020 10 22;8(1):172. Epub 2020 Oct 22.

Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, 32224, USA.

Missense variants ABI3_rs616338-T and PLCG2_rs72824905-G were previously associated with elevated or reduced risk of Alzheimer's disease (AD), respectively. Despite reports of associations with other neurodegenerative diseases, there are few studies of these variants in purely neuropathologically diagnosed cohorts. Further, the effect of these mutations on neurodegenerative disease pathologies is unknown. In this study, we tested the effects of ABI3_rs616338-T and PLCG2_rs72824905-G on disease risk in autopsy cohorts comprised of 973 patients diagnosed neuropathologically with Lewy body disease (LBD-NP) and 1040 with progressive supranuclear palsy (PSP), compared to 3351 controls. LBD-NP patients were further categorized as high, intermediate and low likelihood of clinical dementia with Lewy bodies (DLB-CL) based on DLB Consortium criteria. We also tested for association with both Braak neurofibrillary tau tangle (n = 2008, n = 1037, n = 971) and Thal phase amyloid plaque scores (n = 1786, n = 1018, n = 768). Additionally, 841 PSP patients had quantitative tau neuropathology measures that were assessed for genetic associations. There was no statistically significant association with disease risk for either LBD-NP or PSP in our study. LBD intermediate category disease risk was significantly associated with ABI3_rs616338-T (OR = 2.65, 95% CI 1.46-4.83, p = 0.001). PLCG2_rs72824905-G was associated with lower Braak stage (ß = - 0.822, 95% CI - 1.439 to - 0.204, p = 0.009). This effect was more pronounced in the PSP (ß = - 0.995, 95% CI - 1.773 to - 0.218, p = 0.012) than LBD-NP patients (ß = - 0.292, 95% CI - 1.283 to 0.698, p = 0.563). PLCG2_rs72824905-G also showed association with reduced quantitative tau pathology for each lesion type and overall tau burden in PSP (ß = - 0.638, 95% CI - 1.139 to - 0.136, p = 0.013). These findings support a role for PLCG2_rs72824905-G in suppressing tau neuropathology. ABI3_rs616338-T may influence disease risk specifically in the LBD-NP intermediate category comprised of patients with diffuse neocortical or limbic LB, concurrently with moderate or high AD neuropathology, respectively. Our study provides a potential mechanism of action for the missense PLCG2 variant and suggests a differential disease risk effect for ABI3 in a distinct LBD-NP neuropathologic category.
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http://dx.doi.org/10.1186/s40478-020-01050-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7579984PMC
October 2020

Mitophagy alterations in Alzheimer's disease are associated with granulovacuolar degeneration and early tau pathology.

Alzheimers Dement 2020 Oct 8. Epub 2020 Oct 8.

Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA.

Introduction: The cytoprotective PTEN-induced kinase 1 (PINK1)-parkin RBR E3 ubiquitin protein ligase (PRKN) pathway selectively labels damaged mitochondria with phosphorylated ubiquitin (pS65-Ub) for their autophagic removal (mitophagy). Because dysfunctions of mitochondria and degradation pathways are early features of Alzheimer's disease (AD), mitophagy impairments may contribute to the pathogenesis.

Methods: Morphology, levels, and distribution of the mitophagy tag pS65-Ub were evaluated by biochemical analyses combined with tissue and single cell imaging in AD autopsy brain and in transgenic mouse models.

Results: Analyses revealed significant increases of pS65-Ub levels in AD brain, which strongly correlated with granulovacuolar degeneration (GVD) and early phospho-tau deposits, but were independent of amyloid beta pathology. Single cell analyses revealed predominant co-localization of pS65-Ub with mitochondria, GVD bodies, and/or lysosomes depending on the brain region analyzed.

Discussion: Our study highlights mitophagy alterations in AD that are associated with early tau pathology, and suggests that distinct mitochondrial, autophagic, and/or lysosomal failure may contribute to the selective vulnerability in disease.
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http://dx.doi.org/10.1002/alz.12198DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8048674PMC
October 2020

Novel Alzheimer Disease Risk Loci and Pathways in African American Individuals Using the African Genome Resources Panel: A Meta-analysis.

JAMA Neurol 2021 01;78(1):102-113

Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, New York.

Importance: Compared with non-Hispanic White individuals, African American individuals from the same community are approximately twice as likely to develop Alzheimer disease. Despite this disparity, the largest Alzheimer disease genome-wide association studies to date have been conducted in non-Hispanic White individuals. In the largest association analyses of Alzheimer disease in African American individuals, ABCA7, TREM2, and an intergenic locus at 5q35 were previously implicated.

Objective: To identify additional risk loci in African American individuals by increasing the sample size and using the African Genome Resource panel.

Design, Setting, And Participants: This genome-wide association meta-analysis used case-control and family-based data sets from the Alzheimer Disease Genetics Consortium. There were multiple recruitment sites throughout the United States that included individuals with Alzheimer disease and controls of African American ancestry. Analysis began October 2018 and ended September 2019.

Main Outcomes And Measures: Diagnosis of Alzheimer disease.

Results: A total of 2784 individuals with Alzheimer disease (1944 female [69.8%]) and 5222 controls (3743 female [71.7%]) were analyzed (mean [SD] age at last evaluation, 74.2 [13.6] years). Associations with 4 novel common loci centered near the intracellular glycoprotein trafficking gene EDEM1 (3p26; P = 8.9 × 10-7), near the immune response gene ALCAM (3q13; P = 9.3 × 10-7), within GPC6 (13q31; P = 4.1 × 10-7), a gene critical for recruitment of glutamatergic receptors to the neuronal membrane, and within VRK3 (19q13.33; P = 3.5 × 10-7), a gene involved in glutamate neurotoxicity, were identified. In addition, several loci associated with rare variants, including a genome-wide significant intergenic locus near IGF1R at 15q26 (P = 1.7 × 10-9) and 6 additional loci with suggestive significance (P ≤ 5 × 10-7) such as API5 at 11p12 (P = 8.8 × 10-8) and RBFOX1 at 16p13 (P = 5.4 × 10-7) were identified. Gene expression data from brain tissue demonstrate association of ALCAM, ARAP1, GPC6, and RBFOX1 with brain β-amyloid load. Of 25 known loci associated with Alzheimer disease in non-Hispanic White individuals, only APOE, ABCA7, TREM2, BIN1, CD2AP, FERMT2, and WWOX were implicated at a nominal significance level or stronger in African American individuals. Pathway analyses strongly support the notion that immunity, lipid processing, and intracellular trafficking pathways underlying Alzheimer disease in African American individuals overlap with those observed in non-Hispanic White individuals. A new pathway emerging from these analyses is the kidney system, suggesting a novel mechanism for Alzheimer disease that needs further exploration.

Conclusions And Relevance: While the major pathways involved in Alzheimer disease etiology in African American individuals are similar to those in non-Hispanic White individuals, the disease-associated loci within these pathways differ.
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http://dx.doi.org/10.1001/jamaneurol.2020.3536DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7573798PMC
January 2021

Large eQTL meta-analysis reveals differing patterns between cerebral cortical and cerebellar brain regions.

Sci Data 2020 10 12;7(1):340. Epub 2020 Oct 12.

Sage Bionetworks, Seattle, WA, 98121, USA.

The availability of high-quality RNA-sequencing and genotyping data of post-mortem brain collections from consortia such as CommonMind Consortium (CMC) and the Accelerating Medicines Partnership for Alzheimer's Disease (AMP-AD) Consortium enable the generation of a large-scale brain cis-eQTL meta-analysis. Here we generate cerebral cortical eQTL from 1433 samples available from four cohorts (identifying >4.1 million significant eQTL for >18,000 genes), as well as cerebellar eQTL from 261 samples (identifying 874,836 significant eQTL for >10,000 genes). We find substantially improved power in the meta-analysis over individual cohort analyses, particularly in comparison to the Genotype-Tissue Expression (GTEx) Project eQTL. Additionally, we observed differences in eQTL patterns between cerebral and cerebellar brain regions. We provide these brain eQTL as a resource for use by the research community. As a proof of principle for their utility, we apply a colocalization analysis to identify genes underlying the GWAS association peaks for schizophrenia and identify a potentially novel gene colocalization with lncRNA RP11-677M14.2 (posterior probability of colocalization 0.975).
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http://dx.doi.org/10.1038/s41597-020-00642-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7550587PMC
October 2020

Correction to: Deciphering cellular transcriptional alterations in Alzheimer's disease brains.

Mol Neurodegener 2020 09 15;15(1):54. Epub 2020 Sep 15.

Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA.

An amendment to this paper has been published and can be accessed via the original article.
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http://dx.doi.org/10.1186/s13024-020-00403-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7490892PMC
September 2020

Tau and apolipoprotein E modulate cerebrovascular tight junction integrity independent of cerebral amyloid angiopathy in Alzheimer's disease.

Alzheimers Dement 2020 10 22;16(10):1372-1383. Epub 2020 Aug 22.

Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA.

Introduction: Cerebrovascular pathologies including cerebral amyloid angiopathy (CAA) and blood-brain barrier (BBB) dysregulation are prominent features in the majority of Alzheimer's disease (AD) cases.

Methods: We performed neuropathologic and biochemical studies on a large, neuropathologically confirmed human AD cohort (N = 469). Amounts of endothelial tight junction proteins claudin-5 (CLDN5) and occludin (OCLN), and major AD-related molecules (amyloid beta [Aβ40], Aβ42, tau, p-tau, and apolipoprotein E) in the temporal cortex were assessed by ELISA.

Results: Higher levels of soluble tau, insoluble p-tau, and apolipoprotein E (apoE) were independently correlated with lower levels of endothelial tight junction proteins CLDN5 and OCLN in AD brains. Although high Aβ40 levels, APOE ε4, and male sex were predominantly associated with exacerbated CAA severity, those factors did not influence tight junction protein levels.

Discussion: Refining the molecular mechanisms connecting tau, Aβ, and apoE with cerebrovascular pathologies is critical for greater understanding of AD pathogenesis and establishing effective therapeutic interventions for the disease.
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http://dx.doi.org/10.1002/alz.12104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8103951PMC
October 2020

Atlas of Transcription Factor Binding Sites from ENCODE DNase Hypersensitivity Data across 27 Tissue Types.

Cell Rep 2020 08;32(7):108029

Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201, USA. Electronic address:

Characterizing the tissue-specific binding sites of transcription factors (TFs) is essential to reconstruct gene regulatory networks and predict functions for non-coding genetic variation. DNase-seq footprinting enables the prediction of genome-wide binding sites for hundreds of TFs simultaneously. Despite the public availability of high-quality DNase-seq data from hundreds of samples, a comprehensive, up-to-date resource for the locations of genomic footprints is lacking. Here, we develop a scalable footprinting workflow using two state-of-the-art algorithms: Wellington and HINT. We apply our workflow to detect footprints in 192 ENCODE DNase-seq experiments and predict the genomic occupancy of 1,515 human TFs in 27 human tissues. We validate that these footprints overlap true-positive TF binding sites from ChIP-seq. We demonstrate that the locations, depth, and tissue specificity of footprints predict effects of genetic variants on gene expression and capture a substantial proportion of genetic risk for complex traits.
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http://dx.doi.org/10.1016/j.celrep.2020.108029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7462736PMC
August 2020

Genome-wide transcriptome analysis identifies novel dysregulated genes implicated in Alzheimer's pathology.

Alzheimers Dement 2020 09 5;16(9):1213-1223. Epub 2020 Aug 5.

Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana.

Introduction: Abnormal gene expression patterns may contribute to the onset and progression of late-onset Alzheimer's disease (LOAD).

Methods: We performed transcriptome-wide meta-analysis (N = 1440) of blood-based microarray gene expression profiles as well as neuroimaging and cerebrospinal fluid (CSF) endophenotype analysis.

Results: We identified and replicated five genes (CREB5, CD46, TMBIM6, IRAK3, and RPAIN) as significantly dysregulated in LOAD. The most significantly altered gene, CREB5, was also associated with brain atrophy and increased amyloid beta (Aβ) accumulation, especially in the entorhinal cortex region. cis-expression quantitative trait loci mapping analysis of CREB5 detected five significant associations (P < 5 × 10 ), where rs56388170 (most significant) was also significantly associated with global cortical Aβ deposition measured by [ F]Florbetapir positron emission tomography and CSF Aβ .

Discussion: RNA from peripheral blood indicated a differential gene expression pattern in LOAD. Genes identified have been implicated in biological processes relevant to Alzheimer's disease. CREB, in particular, plays a key role in nervous system development, cell survival, plasticity, and learning and memory.
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http://dx.doi.org/10.1002/alz.12092DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7541709PMC
September 2020

Meta-Analysis of the Alzheimer's Disease Human Brain Transcriptome and Functional Dissection in Mouse Models.

Cell Rep 2020 07;32(2):107908

Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.

We present a consensus atlas of the human brain transcriptome in Alzheimer's disease (AD), based on meta-analysis of differential gene expression in 2,114 postmortem samples. We discover 30 brain coexpression modules from seven regions as the major source of AD transcriptional perturbations. We next examine overlap with 251 brain differentially expressed gene sets from mouse models of AD and other neurodegenerative disorders. Human-mouse overlaps highlight responses to amyloid versus tau pathology and reveal age- and sex-dependent expression signatures for disease progression. Human coexpression modules enriched for neuronal and/or microglial genes broadly overlap with mouse models of AD, Huntington's disease, amyotrophic lateral sclerosis, and aging. Other human coexpression modules, including those implicated in proteostasis, are not activated in AD models but rather following other, unexpected genetic manipulations. Our results comprise a cross-species resource, highlighting transcriptional networks altered by human brain pathophysiology and identifying correspondences with mouse models for AD preclinical studies.
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http://dx.doi.org/10.1016/j.celrep.2020.107908DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7428328PMC
July 2020

Deciphering cellular transcriptional alterations in Alzheimer's disease brains.

Mol Neurodegener 2020 07 13;15(1):38. Epub 2020 Jul 13.

Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA.

Large-scale brain bulk-RNAseq studies identified molecular pathways implicated in Alzheimer's disease (AD), however these findings can be confounded by cellular composition changes in bulk-tissue. To identify cell intrinsic gene expression alterations of individual cell types, we designed a bioinformatics pipeline and analyzed three AD and control bulk-RNAseq datasets of temporal and dorsolateral prefrontal cortex from 685 brain samples. We detected cell-proportion changes in AD brains that are robustly replicable across the three independently assessed cohorts. We applied three different algorithms including our in-house algorithm to identify cell intrinsic differentially expressed genes in individual cell types (CI-DEGs). We assessed the performance of all algorithms by comparison to single nucleus RNAseq data. We identified consensus CI-DEGs that are common to multiple brain regions. Despite significant overlap between consensus CI-DEGs and bulk-DEGs, many CI-DEGs were absent from bulk-DEGs. Consensus CI-DEGs and their enriched GO terms include genes and pathways previously implicated in AD or neurodegeneration, as well as novel ones. We demonstrated that the detection of CI-DEGs through computational deconvolution methods is promising and highlight remaining challenges. These findings provide novel insights into cell-intrinsic transcriptional changes of individual cell types in AD and may refine discovery and modeling of molecular targets that drive this complex disease.
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http://dx.doi.org/10.1186/s13024-020-00392-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7359236PMC
July 2020