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1.
J Alzheimers Dis ; 85(4): 1573-1582, 2022.
Article in English | MEDLINE | ID: covidwho-1745159

ABSTRACT

BACKGROUND: Subjective cognitive decline (SCD), an at-risk condition of Alzheimer's disease (AD), can involve various cognitive domains, such as memory, language, planning, and attention. OBJECTIVE: We aim to explore the difference in amyloid load between the single memory domain SCD (sd-SCD) and the multidomain SCD (md-SCD) and assess the relationship of amyloid pathology with quantitative SCD scores and objective cognition. METHODS: A total of 63 SCD participants from the SILCODE study underwent the clinical evaluation, neuropsychological assessment, and 18F-florbetapir PET scan. Global amyloid standard uptake value ratio (SUVr) was calculated. Additionally, regional amyloid SUVr was quantified in 12 brain regions of interests. A nonparametric rank ANCOVA was used to compare the global and regional amyloid SUVr between the md-SCD (n = 34) and sd-SCD (n = 29) groups. A multiple linear regression analysis was conducted to test the relationship of amyloid SUVr with quantitative SCD scores and objective cognition. RESULTS: Compared with individuals with sd-SCD, individuals with md-SCD had increased global amyloid SUVr (F = 5.033, p = 0.029) and regional amyloid SUVr in the left middle temporal gyrus (F = 12.309, p = 0.001; Bonferroni corrected), after controlling for the effects of age, sex, and education. When pooling all SCD participants together, the increased global amyloid SUVr was related with higher SCD-plus sum scores and lower Auditory Verbal Learning Test-delayed recall scores. CONCLUSION: According to our findings, individuals with md-SCD showed higher amyloid accumulation than individuals with sd-SCD, suggesting that md-SCD may experience a more advanced stage of SCD. Additionally, increased global amyloid load was predictive of a poorer episodic memory function in SCD individuals.


Subject(s)
Amyloid/metabolism , Cognitive Dysfunction/pathology , Aged , Brain/pathology , Female , Humans , Male , Neuropsychological Tests/statistics & numerical data , Positron-Emission Tomography
2.
ACS Chem Neurosci ; 13(1): 143-150, 2022 01 05.
Article in English | MEDLINE | ID: covidwho-1637498

ABSTRACT

First cases that point at a correlation between SARS-CoV-2 infections and the development of Parkinson's disease (PD) have been reported. Currently, it is unclear if there is also a direct causal link between these diseases. To obtain first insights into a possible molecular relation between viral infections and the aggregation of α-synuclein protein into amyloid fibrils characteristic for PD, we investigated the effect of the presence of SARS-CoV-2 proteins on α-synuclein aggregation. We show, in test tube experiments, that SARS-CoV-2 spike protein (S-protein) has no effect on α-synuclein aggregation, while SARS-CoV-2 nucleocapsid protein (N-protein) considerably speeds up the aggregation process. We observe the formation of multiprotein complexes and eventually amyloid fibrils. Microinjection of N-protein in SH-SY5Y cells disturbed the α-synuclein proteostasis and increased cell death. Our results point toward direct interactions between the N-protein of SARS-CoV-2 and α-synuclein as molecular basis for the observed correlation between SARS-CoV-2 infections and Parkinsonism.


Subject(s)
Amyloid , Coronavirus Nucleocapsid Proteins/metabolism , alpha-Synuclein , Amyloid/metabolism , COVID-19 , Humans , Phosphoproteins/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , alpha-Synuclein/metabolism
3.
Int J Biol Macromol ; 197: 68-76, 2022 Feb 01.
Article in English | MEDLINE | ID: covidwho-1587673

ABSTRACT

The C-terminal domain of SARS-CoV main protease (Mpro-C) can form 3D domain-swapped dimer by exchanging the α1-helices fully buried inside the protein hydrophobic core, under non-denaturing conditions. Here, we report that Mpro-C can also form amyloid fibrils under the 3D domain-swappable conditions in vitro, and the fibrils are not formed through runaway/propagated domain swapping. It is found that there are positive correlations between the rates of domain swapping dimerization and amyloid fibrillation at different temperatures, and for different mutants. However, some Mpro-C mutants incapable of 3D domain swapping can still form amyloid fibrils, indicating that 3D domain swapping is not essential for amyloid fibrillation. Furthermore, NMR H/D exchange data and molecular dynamics simulation results suggest that the protofibril core region tends to unpack at the early stage of 3D domain swapping, so that the amyloid fibrillation can proceed during the 3D domain swapping process. We propose that 3D domain swapping makes it possible for the unpacking of the amyloidogenic fragment of the protein and thus accelerates the amyloid fibrillation process kinetically, which explains the well-documented correlations between amyloid fibrillation and 3D domain swapping observed in many proteins.


Subject(s)
Amyloid/chemistry , Amyloid/metabolism , Amyloidosis/metabolism , Coronavirus 3C Proteases/chemistry , Coronavirus 3C Proteases/metabolism , Protein Domains/physiology , Amyloidosis/genetics , Coronavirus 3C Proteases/genetics , Dimerization , Disulfides/chemistry , Disulfides/metabolism , Kinetics , Models, Molecular , Molecular Dynamics Simulation , Mutation , Polymerization , Protein Conformation, alpha-Helical , Protein Domains/genetics , Protein Folding , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Temperature
4.
Biosci Rep ; 41(8)2021 08 27.
Article in English | MEDLINE | ID: covidwho-1334001

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2)-induced infection, the cause of coronavirus disease 2019 (COVID-19), is characterized by unprecedented clinical pathologies. One of the most important pathologies, is hypercoagulation and microclots in the lungs of patients. Here we study the effect of isolated SARS-CoV-2 spike protein S1 subunit as potential inflammagen sui generis. Using scanning electron and fluorescence microscopy as well as mass spectrometry, we investigate the potential of this inflammagen to interact with platelets and fibrin(ogen) directly to cause blood hypercoagulation. Using platelet-poor plasma (PPP), we show that spike protein may interfere with blood flow. Mass spectrometry also showed that when spike protein S1 is added to healthy PPP, it results in structural changes to ß and γ fibrin(ogen), complement 3, and prothrombin. These proteins were substantially resistant to trypsinization, in the presence of spike protein S1. Here we suggest that, in part, the presence of spike protein in circulation may contribute to the hypercoagulation in COVID-19 positive patients and may cause substantial impairment of fibrinolysis. Such lytic impairment may result in the persistent large microclots we have noted here and previously in plasma samples of COVID-19 patients. This observation may have important clinical relevance in the treatment of hypercoagulability in COVID-19 patients.


Subject(s)
COVID-19/pathology , Fibrin/metabolism , Fibrinolysis/physiology , Spike Glycoprotein, Coronavirus/metabolism , Thrombosis/pathology , Adult , Aged , Amyloid/metabolism , Blood Platelets/metabolism , Complement C3/metabolism , Female , Fibrinogen/metabolism , Humans , Lung/pathology , Male , Microfluidic Analytical Techniques , Middle Aged , Prothrombin/metabolism , SARS-CoV-2/metabolism , Thrombosis/virology , Trypsin/metabolism
5.
Cells ; 10(7)2021 07 13.
Article in English | MEDLINE | ID: covidwho-1314588

ABSTRACT

Transthyretin (TTR) is a tetrameric protein transporting hormones in the plasma and brain, which has many other activities that have not been fully acknowledged. TTR is a positive indicator of nutrition status and is negatively correlated with inflammation. TTR is a neuroprotective and oxidative-stress-suppressing factor. The TTR structure is destabilized by mutations, oxidative modifications, aging, proteolysis, and metal cations, including Ca2+. Destabilized TTR molecules form amyloid deposits, resulting in senile and familial amyloidopathies. This review links structural stability of TTR with the environmental factors, particularly oxidative stress and Ca2+, and the processes involved in the pathogenesis of TTR-related diseases. The roles of TTR in biomineralization, calcification, and osteoarticular and cardiovascular diseases are broadly discussed. The association of TTR-related diseases and vascular and ligament tissue calcification with TTR levels and TTR structure is presented. It is indicated that unaggregated TTR and TTR amyloid are bound by vicious cycles, and that TTR may have an as yet undetermined role(s) at the crossroads of calcification, blood coagulation, and immune response.


Subject(s)
Arthritis/metabolism , Cardiovascular Diseases/metabolism , Osteoporosis/metabolism , Prealbumin/metabolism , Amyloid/chemistry , Amyloid/metabolism , Amyloidosis/metabolism , Animals , Humans , Oxidative Stress , Prealbumin/chemistry , Protein Conformation , Protein Stability
6.
Trends Microbiol ; 29(11): 967-969, 2021 11.
Article in English | MEDLINE | ID: covidwho-1157751

ABSTRACT

Severe coronavirus disease 2019 (COVID-19) infection leads to multifactorial acute respiratory distress syndrome (ARDS), with little therapeutic success. The pathophysiology associated with ARDS or post-ARDS is not yet well understood. We hypothesize that amyloid formation occurring due to protein homeostasis disruption can be one of the complications associated with COVID-19-induced-ARDS.


Subject(s)
Amyloid/metabolism , COVID-19/complications , COVID-19/virology , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/metabolism , SARS-CoV-2 , Amyloidosis/etiology , Amyloidosis/metabolism , Amyloidosis/pathology , Animals , Disease Management , Disease Susceptibility , Humans , Respiratory Distress Syndrome/diagnosis
7.
Biochem Biophys Res Commun ; 554: 94-98, 2021 05 21.
Article in English | MEDLINE | ID: covidwho-1157142

ABSTRACT

The post-infection of COVID-19 includes a myriad of neurologic symptoms including neurodegeneration. Protein aggregation in brain can be considered as one of the important reasons behind the neurodegeneration. SARS-CoV-2 Spike S1 protein receptor binding domain (SARS-CoV-2 S1 RBD) binds to heparin and heparin binding proteins. Moreover, heparin binding accelerates the aggregation of the pathological amyloid proteins present in the brain. In this paper, we have shown that the SARS-CoV-2 S1 RBD binds to a number of aggregation-prone, heparin binding proteins including Aß, α-synuclein, tau, prion, and TDP-43 RRM. These interactions suggests that the heparin-binding site on the S1 protein might assist the binding of amyloid proteins to the viral surface and thus could initiate aggregation of these proteins and finally leads to neurodegeneration in brain. The results will help us to prevent future outcomes of neurodegeneration by targeting this binding and aggregation process.


Subject(s)
Amyloid/metabolism , COVID-19/metabolism , Heparin/metabolism , Neurodegenerative Diseases/metabolism , Protein Aggregation, Pathological , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/metabolism , Amyloid beta-Peptides/metabolism , Brain/metabolism , Brain/pathology , Brain/virology , COVID-19/virology , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Humans , Molecular Docking Simulation , Neurodegenerative Diseases/virology , Prions/metabolism , Protein Binding , SARS-CoV-2/chemistry , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , alpha-Synuclein/metabolism , tau Proteins/metabolism
8.
Amyloid ; 27(4): 217-222, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-889371

ABSTRACT

The ISA Nomenclature Committee met electronically before and directly after the XVII ISA International Symposium on Amyloidosis, which, unfortunately, had to be virtual in September 2020 due to the ongoing COVID-19 pandemic instead of a planned meeting in Tarragona in March. In addition to confirmation of basic nomenclature, several additional concepts were discussed, which are used in scientific amyloid literature. Among such concepts are cytotoxic oligomers, protofibrils, primary and secondary nucleation, seeding and cross-seeding, amyloid signature proteins, and amyloid plaques. Recommendations for their use are given. Definitions of amyloid and amyloidosis are confirmed. Possible novel human amyloid fibril proteins, appearing as 'classical' in vivo amyloid, were discussed. It was decided to include fibulin-like extracellular matrix protein 1 (amyloid protein: AEFEMP1), which appears as localised amyloid in portal veins. There are several possible amyloid proteins under investigation, and these are included in a new Table.


Subject(s)
Amyloid/classification , Amyloidogenic Proteins/classification , Amyloidosis/classification , Terminology as Topic , Amyloid/genetics , Amyloid/metabolism , Amyloidogenic Proteins/genetics , Amyloidogenic Proteins/metabolism , Amyloidosis/diagnosis , Amyloidosis/genetics , Amyloidosis/pathology , COVID-19 , Congresses as Topic , Coronavirus Infections , Education, Distance/organization & administration , Gene Expression , Humans , Pandemics , Pneumonia, Viral
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