scholarly journals Identifying the Main Functional Pathways Associated with Cognitive Resilience to Alzheimer’s Disease

2021 ◽  
Vol 22 (17) ◽  
pp. 9120
Author(s):  
Marta Pérez-González ◽  
Sara Badesso ◽  
Elena Lorenzo ◽  
Elizabeth Guruceaga ◽  
Alberto Pérez-Mediavilla ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mononuclear Cells ◽  
Memory Function ◽  
Temporal Cortex ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear ◽  
Novel Treatments ◽  
Peripheral Immune Cells ◽  
The Brain

Understanding the mechanisms involved in cognitive resilience in Alzheimer’s disease (AD) represents a promising strategy to identify novel treatments for dementia in AD. Previous findings from our group revealed that the study of aged-Tg2576 cognitive resilient individuals is a suitable tool for this purpose. In the present study, we performed a transcriptomic analysis using the prefrontal cortex of demented and resilient Tg2576 transgenic AD mice. We have been able to hypothesize that pathways involved in inflammation, amyloid degradation, memory function, and neurotransmission may be playing a role on cognitive resilience in AD. Intriguingly, the results obtained in this study are suggestive of a reduction of the influx of peripheral immune cells into the brain on cognitive resilient subjects. Indeed, Cd4 mRNA expression is significantly reduced on Tg2576 mice with cognitive resilience. For further validation of this result, we analyzed CD4 expression in human AD samples, including temporal cortex and peripheral blood mononuclear cells (PBMC). Interestingly, we have found a negative correlation between CD4 mRNA levels in the periphery and the score in the Mini-Mental State Exam of AD patients. These findings highlight the importance of understanding the role of the immune system on the development of neurodegenerative diseases and points out to the infiltration of CD4+ cells in the brain as a key player of cognitive dysfunction in AD.

scholarly journals Diagnosing Alzheimer’s Disease from Circulating Blood Leukocytes Using a Fluorescent Amyloid Probe

2021 ◽  
pp. 1-14
Author(s):  
Stefanie A.G. Black ◽  
Anastasiia A. Stepanchuk ◽  
George W. Templeton ◽  
Yda Hernandez ◽  
Tomoko Ota ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Protein Misfolding ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Amyloid Β ◽  
Csf Biomarkers ◽  
Blood Leukocytes ◽  
Peripheral Blood Mononuclear ◽  
The Brain

Background: Toxic amyloid-β (Aβ) peptides aggregate into higher molecular weight assemblies and accumulate not only in the extracellular space, but also in the walls of blood vessels in the brain, increasing their permeability, and promoting immune cell migration and activation. Given the prominent role of the immune system, phagocytic blood cells may contact pathological brain materials. Objective: To develop a novel method for early Alzheimer’s disease (AD) detection, we used blood leukocytes, that could act as “sentinels” after trafficking through the brain microvasculature, to detect pathological amyloid by labelling with a conformationally-sensitive fluorescent amyloid probe and imaging with confocal spectral microscopy. Methods: Formalin-fixed peripheral blood mononuclear cells (PBMCs) from cognitively healthy control (HC) subjects, mild cognitive impairment (MCI) and AD patients were stained with the fluorescent amyloid probe K114, and imaged. Results were validated against cerebrospinal fluid (CSF) biomarkers and clinical diagnosis. Results: K114-labeled leukocytes exhibited distinctive fluorescent spectral signatures in MCI/AD subjects. Comparing subjects with single CSF biomarker-positive AD/MCI to negative controls, our technique yielded modest AUCs, which improved to the 0.90 range when only MCI subjects were included in order to measure performance in an early disease state. Combining CSF Aβ 42 and t-Tau metrics further improved the AUC to 0.93. Conclusion: Our method holds promise for sensitive detection of AD-related protein misfolding in circulating leukocytes, particularly in the early stages of disease.

Muscarinic Receptors Expression in the Peripheral Blood Cells Differentiate Dementia with Lewy Bodies from Alzheimer’s Disease

2021 ◽  
pp. 1-8
Author(s):  
Marcella Reale ◽  
Claudia Carrarini ◽  
Mirella Russo ◽  
Fedele Dono ◽  
Laura Ferri ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Peripheral Blood ◽  
Dementia With Lewy Bodies ◽  
Mononuclear Cells ◽  
Lewy Bodies ◽  
Acetylcholinesterase Inhibitors ◽  
Operating Characteristics ◽  
Peripheral Blood Mononuclear

Background: Central nervous system disruption of cholinergic (ACh) signaling, which plays a major role in cognitive processes, is well documented in dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD). The expression of muscarinic ACh receptors type 1 and 4 (CHRM1 and CHRM4) has been reported to be altered in the brain of DLB patients. Objective: We aim to assess the peripheral gene expression of CHRM1 and 4 in DLB as a possible marker as compared to AD and healthy control (HC) subjects. Methods: Peripheral blood mononuclear cells were collected from 21 DLB, 13 AD, and 8 HC matched subjects. RT-PCR was performed to estimate gene expression of CHRM1 and CHRM4. Results: Peripheral CHRM1 expression was higher and CHRM4 was lower in DLB and AD compared to HC, whereas both CHRM1 and CHRM4 levels were higher in AD compared to DLB patients. Receiver operating characteristics curves, with logistic regression analysis, showed that combining peripheral CHRM1 and CHRM4 levels, DLB and AD subjects were classified with an accuracy of 76.0%. Conclusion: Alterations of peripheral CHRM1 and CHRM4 was found in both AD and DLB patients as compared to HC. CHRM1 and CHRM4 gene expression resulted to be lower in DLB patients compared to AD. In the future, peripheral CHRM expression could be studied as a possible marker of neurodegenerative conditions associated with cholinergic deficit and a possible marker of response to acetylcholinesterase inhibitors.

scholarly journals GPCR19 regulates P2X7R-mediated NLRP3 inflammasomal activation of microglia by Amyloid β in Alzheimer’s diseases

2020 ◽  
Author(s):  
Jahirul Islam ◽  
Jung-Ah Cho ◽  
Ju-yong Kim ◽  
Kyung-Sun Park ◽  
Young-Jae koh ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Nlrp3 Inflammasome ◽  
Memory Function ◽  
Scavenger Receptor ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Priming Phase ◽  
5Xfad Mice ◽  
The Brain

Abstract Amyloid β (Aβ) and/or ATP activates NLRP3 inflammasome (N3I) by P2 × 7R ion channel of microglia, which is crucial in neuroinflammation shown in Alzheimer’s disease (AD). Due to polymorphisms, subtypes, and ubiquitous expression of P2 × 7R, inhibition of P2 × 7R has not been effective for AD. We first report that GPCR19 is a prerequisite for P2 × 7R-mediated N3I activation and Taurodeoxycholate (TDCA), a GPCR19 ligand, inhibited the priming phase of N3I activation, suppressed P2 × 7R expression and P2 × 7R-mediated Ca++ mobilization, and N3I oligomerization which is essential for production of IL-1β/IL-18. Further, TDCA increased expression of scavenger receptor (SR) A, enhanced phagocytosis of Aβ, and decreased Aβ plaque numbers in the brain of 5x Familial Alzheimer’s disease (5xFAD) mice. TDCA also reduced microgliosis, prevented neuronal loss, and improved memory function of 5xFAD mice. The pleiotropic roles of GPCR19 in P2 × 7-mediated N3I activation suggest that targeting GPCR19 might resolve neuroinflammation in AD patients.

scholarly journals Alpha1-chimaerin, a Rac1 GTPase-activating protein, is expressed at reduced mRNA levels in the brain of Alzheimer’s disease patients

2015 ◽  
Vol 591 ◽  
pp. 19-24 ◽  
Author(s):  
Tomoko Kato ◽  
Yoshihiro Konishi ◽  
Shun Shimohama ◽  
Thomas G. Beach ◽  
Hiroyasu Akatsu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mrna Levels ◽  
Gtpase Activating Protein ◽  
Rac1 Gtpase ◽  
The Brain

scholarly journals Rs5848 Variant Influences GRN mRNA Levels in Brain and Peripheral Mononuclear Cells in Patients with Alzheimer's Disease

2009 ◽  
Vol 18 (3) ◽  
pp. 603-612 ◽  
Author(s):  
Chiara Fenoglio ◽  
Daniela Galimberti ◽  
Francesca Cortini ◽  
John S.K. Kauwe ◽  
Carlos Cruchaga ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mononuclear Cells ◽  
Mrna Levels ◽  
Peripheral Mononuclear Cells

scholarly journals Impaired Innate Immunity Mechanisms in the Brain of Alzheimer’s Disease

2020 ◽  
Vol 21 (3) ◽  
pp. 1126 ◽  
Author(s):  
Martina Romagnoli ◽  
Elisa Porcellini ◽  
Ilaria Carbone ◽  
Robert Veerhuis ◽  
Federico Licastro
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Expression Profiles ◽  
Temporal Cortex ◽  
Gene Expression Profiles ◽  
Mrna Levels ◽  
Virus Infections ◽  
Apoe Ε4 ◽  
Age Related ◽  
Persistent Virus

Among environmental factors likely associated with Alzheimer’s disease (AD), persistent virus infections, and age-related progressive decline of immune competence might play a pivotal role. However, AD antimicrobial brain immune responses are poorly investigated. The present study focused on genes involved in antimicrobial defenses, especially against virus infections, in the AD brain. In particular, mRNA levels of IRF7, MED23, IL28B, and IFN-α genes were analyzed in hippocampus and temporal cortex brain samples from AD and non-demented controls. All subjects were also genotyped for APOE ε, IRF7, MED23, and IL28B gene polymorphisms. Most AD patients showed decreased mRNA levels of all investigated genes in the hippocampus and temporal cortex. However, a small group of AD patients showed increased hippocampal mRNA expression of MED23, IL28B, and IFN-α. mRNA levels of MED23, IL28B, IFN-α from the hippocampus and those of MED23 from the temporal cortex were further decreased in APOE ε4 allele AD carriers. Moreover, rs6598008 polymorphism of IRF7 was significantly associated with decreased hippocampal expression of IRF7, MED23, IL28B, and IFN-α. These findings suggest that AD brains show impaired innate antimicrobial gene expression profiles, and individual genetic makeup, such as positivity for the APOE ε4 and IRF7 A alleles, might affect brain immune efficiency.

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