scholarly journals Platelet phosphorylated TDP-43: An exploratory study for a peripheral surrogate biomarker development for Alzheimer’s disease

2017 ◽  
Author(s):  
Rodger Wilhite ◽  
Jessica Sage ◽  
Abdurrahman Bouzid ◽  
Tyler Primavera ◽  
Abdulbaki Agbas
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Early Stage ◽  
Clinical Signs ◽  
Brain Regions ◽  
Post Mortem ◽  
Disease Prognosis ◽  
Post Mortem Brain ◽  
And Control ◽  
Lateral Sclerosis

AbstractAim: Alzheimer’s disease (AD) and other forms of dementia create a non-curable disease population in World’s societies. To develop a blood-based biomarker is important so that the remedial or disease-altering therapeutic intervention for AD patients would be available at the early stage. Materials & Methods: TDP-43 levels were analyzed in post-mortem brain tissue and platelets of AD and control subjects. Results: We observed an increased TDP-43 (<60%) in post-mortem AD brain regions and similar trends were also observed in patient’s platelets. Conclusion: Platelet TDP-43 could be used as a surrogate biomarker that is measurable, reproducible, and sensitive for screening the patients with some early clinical signs of AD and can be used to monitor disease prognosis.Lay abstractIn this study, we explore to identify an Alzheimer’s disease-selective phospho-specific antibody that recognizes the diseased form of TDP-43 protein in patient’s blood-derived platelets. Our results suggest that selective anti-phosphorylated TDP-43 antibody discriminates Alzheimer’s disease from non-demented controls and patients with amyotrophic lateral sclerosis. Therefore, platelet screening with a selective antibody could potentially be a useful tool for diagnostic purposes for Alzheimer’s disease.

scholarly journals Emergence of distinct and heterogeneous strains of amyloid beta with advanced Alzheimer’s disease pathology in Down syndrome

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Alison M. Maxwell ◽  
Peng Yuan ◽  
Brianna M. Rivera ◽  
Wilder Schaaf ◽  
Mihovil Mladinov ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Down Syndrome ◽  
Amyloid Beta ◽  
Fluorescent Probes ◽  
Clinical Symptoms ◽  
Critical Role ◽  
Post Mortem ◽  
Post Mortem Brain ◽  
And Control

AbstractAmyloid beta (Aβ) is thought to play a critical role in the pathogenesis of Alzheimer’s disease (AD). Prion-like Aβ polymorphs, or “strains”, can have varying pathogenicity and may underlie the phenotypic heterogeneity of the disease. In order to develop effective AD therapies, it is critical to identify the strains of Aβ that might arise prior to the onset of clinical symptoms and understand how they may change with progressing disease. Down syndrome (DS), as the most common genetic cause of AD, presents promising opportunities to compare such features between early and advanced AD. In this work, we evaluate the neuropathology and Aβ strain profile in the post-mortem brain tissues of 210 DS, AD, and control individuals. We assayed the levels of various Aβ and tau species and used conformation-sensitive fluorescent probes to detect differences in Aβ strains among individuals and populations. We found that these cohorts have some common but also some distinct strains from one another, with the most heterogeneous populations of Aβ emerging in subjects with high levels of AD pathology. The emergence of distinct strains in DS at these later stages of disease suggests that the confluence of aging, pathology, and other DS-linked factors may favor conditions that generate strains that are unique from sporadic AD.

scholarly journals Integrated miRNA-Seq and mRNA-Seq Study to Identify miRNAs Associated With Alzheimer’s Disease Using Post-mortem Brain Tissue Samples

2021 ◽  
Vol 15 ◽  
Author(s):  
Qingqin S. Li ◽  
Diana Cai
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Immune System ◽  
Inferior Frontal Gyrus ◽  
Wnt Signaling Pathway ◽  
Amyloid Β ◽  
Brain Regions ◽  
Differentially Expressed ◽  
Post Mortem ◽  
Post Mortem Brain

Alzheimer’s disease (AD), the leading form of dementia, is associated with abnormal tau and β-amyloid accumulation in the brain. We conducted a miRNA-seq study to identify miRNAs associated with AD in the post-mortem brain from the inferior frontal gyrus (IFG, n = 69) and superior temporal gyrus (STG, n = 81). Four and 64 miRNAs were differentially expressed (adjusted p-value &lt; 0.05) in AD compared to cognitively normal controls in the IFG and STG, respectively. We observed down-regulation of several miRNAs that have previously been implicated in AD, including hsa-miR-212-5p and hsa-miR-132-5p, in AD samples across both brain regions, and up-regulation of hsa-miR-146a-5p, hsa-miR-501-3p, hsa-miR-34a-5p, and hsa-miR-454-3p in the STG. The differentially expressed miRNAs were previously implicated in the formation of amyloid-β plaques, the dysregulation of tau, and inflammation. We have also observed differential expressions for dozens of other miRNAs in the STG, including hsa-miR-4446-3p, that have not been described previously. Putative targets of these miRNAs (adjusted p-value &lt; 0.1) were found to be involved in Wnt signaling pathway, MAPK family signaling cascades, sphingosine 1-phosphate (S1P) pathway, adaptive immune system, innate immune system, and neurogenesis. Our results support the finding of dysregulated miRNAs previously implicated in AD and propose additional miRNAs that appear to be dysregulated in AD for experimental follow-up.

scholarly journals Defining early changes in Alzheimer’s disease from RNA sequencing of brain regions differentially affected by pathology

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Boris Guennewig ◽  
Julia Lim ◽  
Lee Marshall ◽  
Andrew N. McCorkindale ◽  
Patrick J. Paasila ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Rna Sequencing ◽  
Neuronal Loss ◽  
Brain Regions ◽  
Post Mortem ◽  
Tau Pathology ◽  
Membrane Spanning ◽  
Immune Related Genes ◽  
Vesicle Secretion

AbstractTau pathology in Alzheimer’s disease (AD) spreads in a predictable pattern that corresponds with disease symptoms and severity. At post-mortem there are cortical regions that range from mildly to severely affected by tau pathology and neuronal loss. A comparison of the molecular signatures of these differentially affected areas within cases and between cases and controls may allow the temporal modelling of disease progression. Here we used RNA sequencing to explore differential gene expression in the mildly affected primary visual cortex and moderately affected precuneus of ten age-, gender- and RNA quality-matched post-mortem brains from AD patients and healthy controls. The two regions in AD cases had similar transcriptomic signatures but there were broader abnormalities in the precuneus consistent with the greater tau load. Both regions were characterised by upregulation of immune-related genes such as those encoding triggering receptor expressed on myeloid cells 2 and membrane spanning 4-domains A6A and milder changes in insulin/IGF1 signalling. The precuneus in AD was also characterised by changes in vesicle secretion and downregulation of the interneuronal subtype marker, somatostatin. The ‘early’ AD transcriptome is characterised by perturbations in synaptic vesicle secretion on a background of neuroimmune dysfunction. In particular, the synaptic deficits that characterise AD may begin with the somatostatin division of inhibitory neurotransmission.

P1-155: Post-Mortem Brain Tissue Characterisation of Inflammatory and Pathological Hallmarks of Alzheimer’s Disease During Disease Progression

2016 ◽  
Vol 12 ◽  
pp. P462-P462
Author(s):  
Martina M. Hughes ◽  
Beatriz G. Perez-Nievas ◽  
Claire Troakes ◽  
Michael Perkinton ◽  
Diane P. Hanger ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Disease Progression ◽  
Brain Tissue ◽  
Post Mortem ◽  
Tissue Characterisation ◽  
Post Mortem Brain

scholarly journals Natriuretic Peptides in Post-mortem Brain Tissue and Cerebrospinal Fluid of Non-demented Humans and Alzheimer’s Disease Patients

2018 ◽  
Vol 12 ◽  
Author(s):  
Simin Mahinrad ◽  
Marjolein Bulk ◽  
Isabelle van der Velpen ◽  
Ahmed Mahfouz ◽  
Willeke van Roon-Mom ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cerebrospinal Fluid ◽  
Brain Tissue ◽  
Natriuretic Peptides ◽  
Post Mortem ◽  
Post Mortem Brain

scholarly journals RNA and Oxidative Stress in Alzheimer’s Disease: Focus on microRNAs

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Akihiko Nunomura ◽  
George Perry
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Protein Misfolding ◽  
Early Stage ◽  
Brain Regions ◽  
Prodromal Stage ◽  
Adaptive Mechanisms ◽  
Therapeutic Tools ◽  
Key Events

Oxidative stress (OS) is one of the major pathomechanisms of Alzheimer’s disease (AD), which is closely associated with other key events in neurodegeneration such as mitochondrial dysfunction, inflammation, metal dysregulation, and protein misfolding. Oxidized RNAs are identified in brains of AD patients at the prodromal stage. Indeed, oxidized mRNA, rRNA, and tRNA lead to retarded or aberrant protein synthesis. OS interferes with not only these translational machineries but also regulatory mechanisms of noncoding RNAs, especially microRNAs (miRNAs). MiRNAs can be oxidized, which causes misrecognizing target mRNAs. Moreover, OS affects the expression of multiple miRNAs, and conversely, miRNAs regulate many genes involved in the OS response. Intriguingly, several miRNAs embedded in upstream regulators or downstream targets of OS are involved also in neurodegenerative pathways in AD. Specifically, seven upregulated miRNAs (miR-125b, miR-146a, miR-200c, miR-26b, miR-30e, miR-34a, miR-34c) and three downregulated miRNAs (miR-107, miR-210, miR-485), all of which are associated with OS, are found in vulnerable brain regions of AD at the prodromal stage. Growing evidence suggests that altered miRNAs may serve as targets for developing diagnostic or therapeutic tools for early-stage AD. Focusing on a neuroprotective transcriptional repressor, REST, and the concept of hormesis that are relevant to the OS response may provide clues to help us understand the role of the miRNA system in cellular and organismal adaptive mechanisms to OS.

Genome-wide profiling and predicted significance of post-mortem brain microRNA in Alzheimer’s disease

2020 ◽  
Vol 191 ◽  
pp. 111352
Author(s):  
Adriane D. Henriques ◽  
Wilcelly Machado-Silva ◽  
Renata E.P. Leite ◽  
Claudia K. Suemoto ◽  
Kátia R.M. Leite ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Post Mortem ◽  
Genome Wide ◽  
Post Mortem Brain

scholarly journals Molecular signatures in post-mortem brain tissue of younger individuals at high risk for Alzheimer's disease as based on APOE genotype

2010 ◽  
Vol 16 (8) ◽  
pp. 836-847 ◽  
Author(s):  
C Conejero-Goldberg ◽  
T M Hyde ◽  
S Chen ◽  
U Dreses-Werringloer ◽  
M M Herman ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
High Risk ◽  
Brain Tissue ◽  
Apoe Genotype ◽  
Molecular Signatures ◽  
Post Mortem ◽  
Post Mortem Brain

scholarly journals Effects of Sex, Age, and Apolipoprotein E Genotype on Brain Ceramides and Sphingosine-1-Phosphate in Alzheimer’s Disease and Control Mice

2021 ◽  
Vol 13 ◽  
Author(s):  
Sandra den Hoedt ◽  
Simone M. Crivelli ◽  
Frank P. J. Leijten ◽  
Mario Losen ◽  
Jo A. A. Stevens ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Acyl Chain ◽  
Brain Regions ◽  
Sex Effects ◽  
Strong Risk Factor ◽  
Acyl Chain Length ◽  
Sphingosine 1 Phosphate ◽  
And Control ◽  
Apolipoprotein E Genotype

Apolipoprotein ε4 (APOE)4 is a strong risk factor for the development of Alzheimer’s disease (AD) and aberrant sphingolipid levels have been implicated in AD. We tested the hypothesis that the APOE4 genotype affects brain sphingolipid levels in AD. Seven ceramides and sphingosine-1-phosphate (S1P) were quantified by LC-MSMS in hippocampus, cortex, cerebellum, and plasma of &lt;3 months and &gt;5 months old human APOE3 and APOE4-targeted replacement mice with or without the familial AD (FAD) background of both sexes (145 animals). APOE4 mice had higher Cer(d18:1/24:0) levels in the cortex (1.7-fold, p = 0.002) than APOE3 mice. Mice with AD background showed higher levels of Cer(d18:1/24:1) in the cortex than mice without (1.4-fold, p = 0.003). S1P levels were higher in all three brain regions of older mice than of young mice (1.7-1.8-fold, all p ≤ 0.001). In female mice, S1P levels in hippocampus (r = −0.54 [−0.70, −0.35], p &lt; 0.001) and in cortex correlated with those in plasma (r = −0.53 [−0.71, −0.32], p &lt; 0.001). Ceramide levels were lower in the hippocampus (3.7–10.7-fold, all p &lt; 0.001), but higher in the cortex (2.3–12.8-fold, p &lt; 0.001) of female than male mice. In cerebellum and plasma, sex effects on individual ceramides depended on acyl chain length (9.5-fold lower to 11.5-fold higher, p ≤ 0.001). In conclusion, sex is a stronger determinant of brain ceramide levels in mice than APOE genotype, AD background, or age. Whether these differences impact AD neuropathology in men and women remains to be investigated.

scholarly journals Small RNA modifications in Alzheimer’s disease

2020 ◽  
Author(s):  
Xudong Zhang ◽  
Fatima Trebak ◽  
Lucas AC Souza ◽  
Junchao Shi ◽  
Tong Zhou ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Prefrontal Cortex ◽  
Small Rna ◽  
Small Rnas ◽  
Post Mortem ◽  
Rna Modifications ◽  
Non Coding Rnas ◽  
And Control

AbstractBackgroundWhile significant advances have been made in uncovering the aetiology of Alzheimer’s disease and related dementias at the genetic level, molecular events at the epigenetic level remain largely undefined. Emerging evidence indicates that small non-coding RNAs (sncRNAs) and their associated RNA modifications are important regulators of complex physiological and pathological processes, including aging, stress responses, and epigenetic inheritance. However, whether small RNAs and their modifications are altered in dementia is not known.MethodsWe performed LC-MS/MS–based, high-throughput assays of small RNA modifications in post-mortem samples of the prefrontal lobe cortices of Alzheimer’s disease (AD) and control individuals. We noted that some of the AD patients has co-occurring vascular cognitive impairment-related pathology (VaD).FindingsWe report altered small RNA modifications in AD samples compared with normal controls. The 15–25-nucleotide (nt) RNA fraction of these samples was enriched for microRNAs, whereas the 30–40-nt RNA fraction was enriched for tRNA-derived small RNAs (tsRNAs), rRNA-derived small RNAs (rsRNAs), and YRNA-derived small RNAs (ysRNAs). Interestingly, most of these altered RNA modifications were detected both in the AD and AD with co-occurring vascular dementia subjects. In addition, sequencing of small RNA in the 30–40-nt fraction from AD cortices revealed reductions in rsRNA-5S, tsRNA-Tyr, and tsRNA-Arg.InterpretationThese data suggest that sncRNAs and their associated modifications are novel signals that may be linked to the pathogenesis and development of Alzheimer’s disease.FundingNIH grants (R01HL122770, R01HL091905, 1P20GM130459, R01HD092431, P50HD098593, GM103440), AHA grant (17IRG33370128), Sigmund Gestetner Foundation Fellowship to P Kehoe.Research in ContextEvidence before this studyAlzheimer’s disease (AD) and vascular dementia (VaD) are marked by cognitive impairment and neuropathologies caused by significant neuronal death. Associated gene mutations are rare in subjects with dementia, and the aetiology of these diseases is still not completely understood. Recent emerging evidence suggests that epigenetic changes are risk factors for the development of dementia. However, studies assessing small RNA modifications—one of the features of epigenetics—in dementia are lacking.Added value of this studyWe used high-throughput liquid chromatography-tandem mass spectrometry and small RNA sequencing to profile small RNA modifications and the composition of small RNAs in post-mortem samples of the prefrontal cortex of AD and control subjects. We detected and quantified 16 types of RNA modifications and identified distinct small non-coding RNAs and modification signatures in AD subjects compared with controls.Implications of all the available evidenceThis study identified novel types and compositions of small RNA modifications in the prefrontal cortex of AD patients compared with control subjects in post-mortem samples. The cellular locations of these RNA modifications and whether they are drivers or outcomes of AD are still not known. However, results from the present study may open new possibilities for dissecting the dementia pathology.

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