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1.
Int J Mol Sci ; 22(24)2021 Dec 19.
Article in English | MEDLINE | ID: covidwho-1580688

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered the pandemic Coronavirus Disease 19 (COVID-19), causing millions of deaths. The elderly and those already living with comorbidity are likely to die after SARS-CoV-2 infection. People suffering from Alzheimer's disease (AD) have a higher risk of becoming infected, because they cannot easily follow health roles. Additionally, those suffering from dementia have a 40% higher risk of dying from COVID-19. Herein, we collected from Gene Expression Omnibus repository the brain samples of AD patients who died of COVID-19 (AD+COVID-19), AD without COVID-19 (AD), COVID-19 without AD (COVID-19) and control individuals. We inspected the transcriptomic and interactomic profiles by comparing the COVID-19 cohort against the control cohort and the AD cohort against the AD+COVID-19 cohort. SARS-CoV-2 in patients without AD mainly activated processes related to immune response and cell cycle. Conversely, 21 key nodes in the interactome are deregulated in AD. Interestingly, some of them are linked to beta-amyloid production and clearance. Thus, we inspected their role, along with their interactors, using the gene ontologies of the biological process that reveals their contribution in brain organization, immune response, oxidative stress and viral replication. We conclude that SARS-CoV-2 worsens the AD condition by increasing neurotoxicity, due to higher levels of beta-amyloid, inflammation and oxidative stress.


Subject(s)
Alzheimer Disease/genetics , COVID-19/complications , COVID-19/genetics , Alzheimer Disease/complications , Alzheimer Disease/virology , Amyloid beta-Peptides/metabolism , Brain/virology , COVID-19/physiopathology , Comorbidity/trends , Databases, Factual , Gene Expression/genetics , Gene Expression Profiling/methods , Humans , Inflammation/metabolism , Neurotoxicity Syndromes/metabolism , Oxidative Stress/physiology , Pandemics , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Transcriptome/genetics
2.
Hum Mol Genet ; 29(6): 955-966, 2020 04 15.
Article in English | MEDLINE | ID: covidwho-1455300

ABSTRACT

γ-secretase is a macromolecular complex that catalyzes intramembranous hydrolysis of more than 100 membrane-bound substrates. The complex is composed of presenilin (PS1 or PS2), anterior pharynx defect-1 (APH-1), nicastrin (NCT) and PEN-2 and early-onset; autosomal dominant forms of Alzheimer's disease (AD) are caused by inheritance of mutations of PS. No mutations in genes encoding NCT, or PEN-2 have been identified to date that cause AD. In this regard, a large genetic meta-analysis of four cohorts consisting of more than 600 000 individuals identified a common missense variant, rs117618017 in the APH1B gene that results in a T27I mutation, as a novel genome-wide significant locus. In order to confirm the findings that rs117618017 is associated with risk of AD, we performed a genetic screen from deep whole genome sequencing of the large NIMH family-based Alzheimer's Disease (AD) dataset. In parallel, we sought to uncover potential molecular mechanism(s) by which APH-1B T27I might be associated with AD by generating stable HEK293 cell lines, wherein endogenous APH-1A and APH-1B expression was silenced and into which either the wild type APH-1B or the APH-1B T27I variant was stably expressed. We then tested the impact of expressing either the wild type APH-1B or the APH-1B T27I variant on γ-secretase processing of human APP, the murine Notch derivative mNΔE and human neuregulin-1. We now report that we fail to confirm the association of rs1047552 with AD in our cohort and that cells expressing the APH-1B T27I variant show no discernable impact on the γ-secretase processing of established substrates compared with cells expressing wild-type APH-1B.


Subject(s)
Alzheimer Disease/pathology , Amyloid Precursor Protein Secretases/metabolism , Endopeptidases/genetics , Membrane Proteins/genetics , Polymorphism, Single Nucleotide , Alzheimer Disease/genetics , HEK293 Cells , Humans , Mutation , Protein Binding
3.
Mol Neurobiol ; 58(10): 5356-5368, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1326854

ABSTRACT

The pandemic of novel coronavirus 2 (SARS-CoV-2) has made global chaos for normal human living. Despite common COVID-19 symptoms, variability in clinical phenotypes was reported worldwide. Reports on SARS-CoV-2 suggest causing neurological manifestation. In addition, the susceptibility of SARS-CoV-2 in patients with neurodegenerative diseases and its complexity are largely unclear. Here, we aimed to demonstrate the possible transport of exosome from SARS-CoV-2-infected lungs to the brain regions associated with neurodegenerative diseases using multiple transcriptome datasets of SARS-CoV-2-infected lungs, RNA profiles from lung exosome, and gene expression profiles of the human brain. Upon transport, the transcription factors localized in the exosome regulate genes at lateral substantia nigra, medial substantia nigra, and superior frontal gyrus regions of Parkinson's disease (PD) and frontal cortex, hippocampus, and temporal cortex of Alzheimer's disease (AD). On SARS-CoV-2 infection, BCL3, JUND, MXD1, IRF2, IRF9, and STAT1 transcription factors in the exosomes influence the neuronal gene regulatory network and accelerate neurodegeneration. STAT1 transcription factor regulates 64 PD genes at lateral substantia nigra, 65 at superior frontal gyrus, and 19 at medial substantia nigra. Similarly, in AD, STAT1 regulates 74 AD genes at the temporal cortex, 40 genes at the hippocampus, and 16 genes at the frontal cortex. We further demonstrate that dysregulated neuronal genes showed involvement in immune response, signal transduction, apoptosis, and stress response process. In conclusion, SARS-CoV-2 may dysregulate neuronal gene regulatory network through exosomes that attenuate disease severity of neurodegeneration.


Subject(s)
Brain/metabolism , COVID-19/metabolism , Exosomes/metabolism , Lung/metabolism , Neurons/metabolism , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Databases, Factual , Exosomes/genetics , Humans , Parkinson Disease/genetics , Parkinson Disease/metabolism , Transcriptome
4.
Alzheimers Res Ther ; 13(1): 111, 2021 Jun 12.
Article in English | MEDLINE | ID: covidwho-1266503

ABSTRACT

Challenges have been recognized in healthcare of patients with Alzheimer's disease (AD) in the COVID-19 pandemic, given a high infection and mortality rate of COVID-19 in these patients. This situation urges the identification of underlying risks and preferably biomarkers for evidence-based, more effective healthcare. Towards this goal, current literature review and network analysis synthesize available information on the AD-related gene APOE into four lines of mechanistic evidence. At a cellular level, the risk isoform APOE4 confers high infectivity by the underlying coronavirus SARS-CoV-2; at a genetic level, APOE4 is associated with severe COVID-19; at a pathway level, networking connects APOE with COVID-19 risk factors such as ACE2, TMPRSS2, NRP1, and LZTFL1; at a behavioral level, APOE4-associated dementia may increase the exposure to coronavirus infection which causes COVID-19. Thus, APOE4 could exert multiple actions for high infection and mortality rates of the patients, or generally, with COVID-19.


Subject(s)
Alzheimer Disease , COVID-19 , Alzheimer Disease/genetics , Apolipoprotein E4/genetics , Humans , Pandemics , SARS-CoV-2
5.
Alzheimers Res Ther ; 13(1): 110, 2021 06 09.
Article in English | MEDLINE | ID: covidwho-1262514

ABSTRACT

BACKGROUND: Dementia-like cognitive impairment is an increasingly reported complication of SARS-CoV-2 infection. However, the underlying mechanisms responsible for this complication remain unclear. A better understanding of causative processes by which COVID-19 may lead to cognitive impairment is essential for developing preventive and therapeutic interventions. METHODS: In this study, we conducted a network-based, multimodal omics comparison of COVID-19 and neurologic complications. We constructed the SARS-CoV-2 virus-host interactome from protein-protein interaction assay and CRISPR-Cas9-based genetic assay results and compared network-based relationships therein with those of known neurological manifestations using network proximity measures. We also investigated the transcriptomic profiles (including single-cell/nuclei RNA-sequencing) of Alzheimer's disease (AD) marker genes from patients infected with COVID-19, as well as the prevalence of SARS-CoV-2 entry factors in the brains of AD patients not infected with SARS-CoV-2. RESULTS: We found significant network-based relationships between COVID-19 and neuroinflammation and brain microvascular injury pathways and processes which are implicated in AD. We also detected aberrant expression of AD biomarkers in the cerebrospinal fluid and blood of patients with COVID-19. While transcriptomic analyses showed relatively low expression of SARS-CoV-2 entry factors in human brain, neuroinflammatory changes were pronounced. In addition, single-nucleus transcriptomic analyses showed that expression of SARS-CoV-2 host factors (BSG and FURIN) and antiviral defense genes (LY6E, IFITM2, IFITM3, and IFNAR1) was elevated in brain endothelial cells of AD patients and healthy controls relative to neurons and other cell types, suggesting a possible role for brain microvascular injury in COVID-19-mediated cognitive impairment. Overall, individuals with the AD risk allele APOE E4/E4 displayed reduced expression of antiviral defense genes compared to APOE E3/E3 individuals. CONCLUSION: Our results suggest significant mechanistic overlap between AD and COVID-19, centered on neuroinflammation and microvascular injury. These results help improve our understanding of COVID-19-associated neurological manifestations and provide guidance for future development of preventive or treatment interventions, although causal relationship and mechanistic pathways between COVID-19 and AD need future investigations.


Subject(s)
Alzheimer Disease , COVID-19 , Cognitive Dysfunction , Alzheimer Disease/genetics , Brain , Endothelial Cells , Humans , Membrane Proteins , RNA-Binding Proteins , SARS-CoV-2
6.
J Alzheimers Dis ; 79(3): 1015-1021, 2021.
Article in English | MEDLINE | ID: covidwho-1060642

ABSTRACT

We explored the impact of the Spanish COVID-19 strict home confinement on mental health and cognition in non-infected subjects (N = 16, 60-80 years) diagnosed with subjective cognitive decline and APOEɛ3/ɛ4 carriers. Mental health was monitored for 2 months on a daily, weekly, or monthly basis, and compared to pre-confinement values. Emotional distress, anxiety, and depression scores increased to pathological threshold values during and after confinement. Those with lower mood during confinement experienced a decline in their mood after confinement. Cognition did not change. These preliminary results suggest that mental health consequences of corona measures in preclinical stages of Alzheimer's disease should be further evaluated.


Subject(s)
Alzheimer Disease/psychology , COVID-19/psychology , Cognition Disorders/psychology , Mental Health , Quarantine/psychology , Aged , Aged, 80 and over , Alzheimer Disease/diagnosis , Alzheimer Disease/genetics , Anxiety Disorders/diagnosis , Anxiety Disorders/genetics , Anxiety Disorders/psychology , Apolipoprotein E3/genetics , Apolipoprotein E4/genetics , COVID-19/genetics , COVID-19/therapy , Cognition Disorders/diagnosis , Cognition Disorders/genetics , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/genetics , Cognitive Dysfunction/psychology , Depressive Disorder/diagnosis , Depressive Disorder/genetics , Depressive Disorder/psychology , Female , Humans , Male , Middle Aged , Psychological Distress , Risk , Spain
8.
Med Hypotheses ; 147: 110479, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-1009752

ABSTRACT

The association of the coronavirus disease 2019 (COVID-19) with significant neurological and neuropsychiatric complications has been increasingly reported, both during the acute illness and in its aftermath. However, due to the short duration of patient follow up until now, it is not clear whether this infection will be associated with longer-term neurological and/or neuropsychiatric sequelae. In particular, the question of whether COVID-19 will be associated with an increased risk and rate of future dementia remains open and subject to speculation. During the course of the COVID-19 pandemic, an increasing number of patients have reported sudden anosmia or other olfactory dysfunction as concurrent symptoms. The possibility that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may reach the brain via the olfactory nerve or an upper nasal trancribrial route is an interesting working hypothesis. Among the identified genetic risk factors for Late-onset Alzheimer's disease (LOAD), Apo E4 is one of the strongest and most frequent. People carrying one or two copies of the e4 allele of Apo E4 have significant odor recognition deficits in comparison to those not carrying this haplotype. The hypothesis invoked in this paper is that anosmia/olfactory dysfunctions induced by SARS-CoV-2 may cause an increased a risk of future neurodegenerative dementia in ApoE4 carriers, and that this risk would be higher than in Apo E4 carriers affected by anosmia not induced by SARS-CoV-2. This would be associated with virus-induced chronic modifications in the central nervous system. It is proposed that COVID-19 patients with anosmia and no other serious symptoms should be followed up as part of specifically designed and approved studies in order to identify the early stages of dementia (especially LOAD and Dementia with Lewy Bodies), thereby improving our knowledge of the mechanisms involved in pre-cognitive stages of neurodegenerative dementia and making best use of any available therapies. This latter opportunity is unique and should not be lost.


Subject(s)
Alzheimer Disease/genetics , Anosmia/complications , Apolipoprotein E4/genetics , COVID-19/complications , Dementia/genetics , Olfaction Disorders/complications , Alzheimer Disease/complications , Dementia/complications , Humans , Inflammation , Models, Theoretical , Prevalence , Risk , Smell
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