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1.
J Phys Chem B ; 126(20): 3648-3658, 2022 05 26.
Article in English | MEDLINE | ID: covidwho-1947182

ABSTRACT

Aggregates of α-synuclein are thought to be the disease-causing agent in Parkinson's disease. Various case studies have hinted at a correlation between COVID-19 and the onset of Parkinson's disease. For this reason, we use molecular dynamics simulations to study whether amyloidogenic regions in SARS-COV-2 proteins can initiate and modulate aggregation of α-synuclein. As an example, we choose the nine-residue fragment SFYVYSRVK (SK9), located on the C-terminal of the envelope protein of SARS-COV-2. We probe how the presence of SK9 affects the conformational ensemble of α-synuclein monomers and the stability of two resolved fibril polymorphs. We find that the viral protein fragment SK9 may alter α-synuclein amyloid formation by shifting the ensemble toward aggregation-prone and preferentially rod-like fibril seeding conformations. However, SK9 has only a small effect on the stability of pre-existing or newly formed fibrils. A potential mechanism and key residues for potential virus-induced amyloid formation are described.


Subject(s)
Amyloidogenic Proteins , Coronavirus Envelope Proteins , Parkinson Disease , Peptide Fragments , alpha-Synuclein , Amyloidogenic Proteins/chemistry , Amyloidogenic Proteins/metabolism , COVID-19/virology , Coronavirus Envelope Proteins/chemistry , Coronavirus Envelope Proteins/metabolism , Humans , Parkinson Disease/metabolism , Peptide Fragments/chemistry , Peptide Fragments/metabolism , SARS-CoV-2/metabolism , alpha-Synuclein/chemistry , alpha-Synuclein/metabolism
2.
J Neural Transm (Vienna) ; 129(5-6): 557-562, 2022 06.
Article in English | MEDLINE | ID: covidwho-1894646

ABSTRACT

Parkinson's disease is the second most common neurological disorder marked by characteristic poverty and dysfunction in movement. There are many mechanisms and factors which have been postulated to be associated with the neurodegenerative pathway(s) resulting in distinctive loss of neurons in the substantia nigra. Subsequently, the neuropathology is more widespread and exhibited in other areas of the brain, and enteric nervous system. Aggregates of misfolded α-synuclein or Lewy bodies are the hallmark of the illness and appear to be central in the whole cascade of cell destruction. There are many processes implicated in neuronal destruction including: oxidative stress, excitotoxicity, mitochondrial dysfunction, an imbalance in protein homeostasis and neuroinflammation. Interesting, inflammation induced by pathogens (including, bacteria and viruses) has been associated in the pathogenesis of the disease. Bacteria such as Helicobacter pylori and Helicobacter suis appear to colonise the gut, and elicit systemic immune responses, which is them transmitted via the gut-axis to the brain, where cytotoxic cytokines induce neuroinflammation and cell death. This conforms to the bottom-top hypothesis proposed by Braak. The gut is also implicated in two other theories postulated in the development and progression of the disorder, namely, the top-down and the threshold. There is a possibility that these theories may be inter-linked and operate together to certain degree. Ultimately specific trigger factors or conditions may govern the occurrences of these processes in genetically predisposed individuals. Nevertheless, the importance of pathogen-related gut infections cannot be overlooked, since it can result in dysbiosis of gut microbes, which may orchestrate α-synuclein pathology and eventually cell destruction.


Subject(s)
Parkinson Disease , alpha-Synuclein , Humans , Lewy Bodies/metabolism , Neurons/metabolism , Substantia Nigra/metabolism , alpha-Synuclein/metabolism
3.
Viruses ; 14(4)2022 04 08.
Article in English | MEDLINE | ID: covidwho-1810316

ABSTRACT

SARS-CoV-2 causes acute respiratory disease, but many patients also experience neurological complications. Neuropathological changes with pronounced neuroinflammation have been described in individuals after lethal COVID-19, as well as in the CSF of hospitalized patients with neurological complications. To assess whether neuropathological changes can occur after a SARS-CoV-2 infection, leading to mild-to-moderate disease, we investigated the brains of four rhesus and four cynomolgus macaques after pulmonary disease and without overt clinical symptoms. Postmortem analysis demonstrated the infiltration of T-cells and activated microglia in the parenchyma of all infected animals, even in the absence of viral antigen or RNA. Moreover, intracellular α-synuclein aggregates were found in the brains of both macaque species. The heterogeneity of these manifestations in the brains indicates the virus' neuropathological potential and should be considered a warning for long-term health risks, following SARS-CoV-2 infection.


Subject(s)
COVID-19 , Encephalitis , alpha-Synuclein , Animals , Encephalitis/metabolism , Encephalitis/virology , Macaca mulatta/virology , Protein Aggregates , SARS-CoV-2 , alpha-Synuclein/metabolism
4.
Int J Mol Sci ; 23(6)2022 Mar 21.
Article in English | MEDLINE | ID: covidwho-1753508

ABSTRACT

Growing cases of patients reported have shown a potential relationship between (severe acute respiratory syndrome coronavirus 2) SARS-CoV-2 infection and Parkinson's disease (PD). However, it is unclear whether there is a molecular link between these two diseases. Alpha-synuclein (α-Syn), an aggregation-prone protein, is considered a crucial factor in PD pathology. In this study, bioinformatics analysis confirmed favorable binding affinity between α-Syn and SARS-CoV-2 spike (S) protein and nucleocapsid (N) protein, and direct interactions were further verified in HEK293 cells. The expression of α-Syn was upregulated and its aggregation was accelerated by S protein and N protein. It was noticed that SARS-CoV-2 proteins caused Lewy-like pathology in the presence of α-Syn overexpression. By confirming that SARS-CoV-2 proteins directly interact with α-Syn, our study offered new insights into the mechanism underlying the development of PD on the background of COVID-19.


Subject(s)
COVID-19 , Parkinson Disease , HEK293 Cells , Humans , Lewy Bodies/metabolism , Parkinson Disease/metabolism , SARS-CoV-2 , alpha-Synuclein/metabolism
5.
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
6.
Cells ; 10(3)2021 03 09.
Article in English | MEDLINE | ID: covidwho-1403544

ABSTRACT

The risk of Parkinson's disease increases with age. However, the etiology of the illness remains obscure. It appears highly likely that the neurodegenerative processes involve an array of elements that influence each other. In addition, genetic, endogenous, or exogenous toxins need to be considered as viable partners to the cellular degeneration. There is compelling evidence that indicate the key involvement of modified α-synuclein (Lewy bodies) at the very core of the pathogenesis of the disease. The accumulation of misfolded α-synuclein may be a consequence of some genetic defect or/and a failure of the protein clearance system. Importantly, α-synuclein pathology appears to be a common denominator for many cellular deleterious events such as oxidative stress, mitochondrial dysfunction, dopamine synaptic dysregulation, iron dyshomeostasis, and neuroinflammation. These factors probably employ a common apoptotic/or autophagic route in the final stages to execute cell death. The misfolded α-synuclein inclusions skillfully trigger or navigate these processes and thus amplify the dopamine neuron fatalities. Although the process of neuroinflammation may represent a secondary event, nevertheless, it executes a fundamental role in neurodegeneration. Some viral infections produce parkinsonism and exhibit similar characteristic neuropathological changes such as a modest brain dopamine deficit and α-synuclein pathology. Thus, viral infections may heighten the risk of developing PD. Alternatively, α-synuclein pathology may induce a dysfunctional immune system. Thus, sporadic Parkinson's disease is caused by multifactorial trigger factors and metabolic disturbances, which need to be considered for the development of potential drugs in the disorder.


Subject(s)
Parkinson Disease/metabolism , Substantia Nigra/metabolism , alpha-Synuclein/metabolism , Animals , Dopaminergic Neurons/pathology , Humans , Inflammation/pathology , Parkinson Disease/genetics , Parkinson Disease/pathology , Risk Factors
7.
Mol Med Rep ; 24(4)2021 10.
Article in English | MEDLINE | ID: covidwho-1395037

ABSTRACT

Parkinson's disease (PD) is the second most common neurodegenerative disease amongst the middle­aged and elderly populations. Several studies have confirmed that the microbiota­gut­brain axis (MGBA) serves a key role in the pathogenesis of PD. Changes to the gastrointestinal microbiome (GM) cause misfolding and abnormal aggregation of α­synuclein (α­syn) in the intestine. Abnormal α­syn is not eliminated via physiological mechanisms and is transported into the central nervous system (CNS) via the vagus nerve. The abnormal levels of α­syn aggregate in the substantia nigra pars compacta, not only leading to the formation of eosinophilic Lewis Bodies in the cytoplasm and mitochondrial dysfunction in dopaminergic (DA) neurons, but also leading to the stimulation of an inflammatory response in the microglia. These pathological changes result in an increase in oxidative stress (OS), which triggers nerve cell apoptosis, a characteristic of PD. This increase in OS further oxidizes and intensifies abnormal aggregation of α­syn, eventually forming a positive feedback loop. The present review discusses the abnormal accumulation of α­syn in the intestine caused by the GM changes and the increased levels of α­syn transport to the CNS via the MGBA, resulting in the loss of DA neurons and an increase in the inflammatory response of microglial cells in the brain of patients with PD. In addition, relevant clinical therapeutic strategies for improving the GM and reducing α­syn accumulation to relieve the symptoms and progression of PD are described.


Subject(s)
/physiology , Disease Progression , Gastrointestinal Microbiome/physiology , Parkinson Disease/microbiology , alpha-Synuclein/metabolism , Aged , Bacteria/classification , Brain/metabolism , Dopaminergic Neurons/metabolism , Dysbiosis , Humans , Microglia , Middle Aged , Neurodegenerative Diseases , Oxidative Stress , alpha-Synuclein/genetics
8.
Mol Neurobiol ; 58(9): 4477-4486, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1241710

ABSTRACT

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of human COVID-19, not only causes flu-like symptoms and gut microbiome complications but a large number of infected individuals also experience a host of neurological symptoms including loss of smell and taste, seizures, difficulty concentrating, decreased alertness, and brain inflammation. Although SARS-CoV-2 infections are not more prevalent in Parkinson's disease patients, a higher mortality rate has been reported not only associated with older age and longer disease duration, but also through several mechanisms, such as interactions with the brain dopaminergic system and through systemic inflammatory responses. Indeed, a number of the neurological symptoms seen in COVID-19 patients, as well as the alterations in the gut microbiome, are also prevalent in patients with Parkinson's disease. Furthermore, biochemical pathways such as oxidative stress, inflammation, and protein aggregation have shared commonalities between Parkinson's disease and COVID-19 disease progression. In this review, we describe and compare the numerous similarities and intersections between neurodegeneration in Parkinson's disease and RNA viral infections, emphasizing the current SARS-CoV-2 global health crisis.


Subject(s)
COVID-19/physiopathology , Gastrointestinal Microbiome , Parkinson Disease/physiopathology , SARS-CoV-2 , Aged , COVID-19/complications , COVID-19/mortality , Cognition Disorders/etiology , Cytokines/physiology , Diet , Disease Progression , Dysbiosis/etiology , Dysbiosis/physiopathology , Humans , Inflammation , Metals, Heavy/toxicity , Models, Neurological , Nerve Degeneration , Olfactory Bulb/physiopathology , Olfactory Bulb/virology , Oxidative Stress , Parkinson Disease/etiology , Practice Guidelines as Topic , Protein Aggregation, Pathological/etiology , RNA Virus Infections/metabolism , RNA Virus Infections/physiopathology , Reactive Oxygen Species/metabolism , Sensation Disorders/etiology , alpha-Synuclein/metabolism
9.
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
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