scholarly journals Possible Link between SARS-CoV-2 Infection and Parkinson’s Disease: The Role of Toll-Like Receptor 4

2021 ◽  
Vol 22 (13) ◽  
pp. 7135
Author(s):  
Carmela Conte
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cerebrovascular Diseases ◽  
Substantia Nigra Pars Compacta ◽  
Motor Disorder ◽  
Nigrostriatal Pathway ◽  
Contributing Factors ◽  
Toll Like Receptor 4 ◽  
Non Motor Symptoms

Parkinson’s disease (PD) is the most common neurodegenerative motor disorder characterized by selective degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) of the midbrain, depletion of dopamine (DA), and impaired nigrostriatal pathway. The pathological hallmark of PD includes the aggregation and accumulation α-synuclein (α-SYN). Although the precise mechanisms underlying the pathogenesis of PD are still unknown, the activation of toll-like receptors (TLRs), mainly TLR4 and subsequent neuroinflammatory immune response, seem to play a significant role. Mounting evidence suggests that viral infection can concur with the precipitation of PD or parkinsonism. The recently identified coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of ongoing pandemic coronavirus disease 2019 (COVID-19), responsible for 160 million cases that led to the death of more than three million individuals worldwide. Studies have reported that many patients with COVID-19 display several neurological manifestations, including acute cerebrovascular diseases, conscious disturbance, and typical motor and non-motor symptoms accompanying PD. In this review, the neurotropic potential of SARS-CoV-2 and its possible involvement in the pathogenesis of PD are discussed. Specifically, the involvement of the TLR4 signaling pathway in mediating the virus entry, as well as the massive immune and inflammatory response in COVID-19 patients is explored. The binding of SARS-CoV-2 spike (S) protein to TLR4 and the possible interaction between SARS-CoV-2 and α-SYN as contributing factors to neuronal death are also considered.

scholarly journals Cardiac Tyrosine Hydroxylase Activation and MB-COMT in Dyskinetic Monkeys 

2020 ◽  
Author(s):  
Lorena Cuenca-Bermejo ◽  
Pilar Almela ◽  
Pablo Gallo-Soljancic ◽  
Jose E. Yuste ◽  
Vicente de Pablos ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Tyrosine Hydroxylase ◽  
Substantia Nigra Pars Compacta ◽  
Nigrostriatal Pathway ◽  
Methyl Transferase ◽  
Catecholaminergic System ◽  
Mptp Treatment ◽  
The Impact

Abstract Background: The impact of age-associated disorders is increasing as the life expectancy of the population increments. Cardiovascular diseases and neurodegenerative disorders, such as Parkinson’s disease, have the highest social and economic burden and increasing evidence show interrelations between them. Particularly, dysfunction of the cardiovascular nervous system is part of the dysautonomic symptoms of Parkinson’s disease, although more studies are needed to elucidate the role of cardiac function on it . Methods: We analyzed the dopaminergic system in the nigrostriatal pathway of Parkinsonian and dyskinetic monkeys and the expression of some key proteins in the metabolism and synthesis of catecholamines in the heart: total and phosphorylated (phospho) tyrosine hydroxylase (TH), and membrane (MB) and soluble (S) isoforms of catechol-O-methyl transferase (COMT). Results: The number of dopaminergic neurons in the Substantia Nigra pars compacta and the optical density of TH+ fibers and dopamine transporter in the striatum were significantly decreased in all MPTP-intoxicated monkeys. MPTP- and MPTP+L-DOPA-treated animals also showed a decrease in total TH expression in both right (RV) and left ventricle (LV). We found a significant increase of phospho-TH in both groups (MPTP and MPTP+L-DOPA) in the LV, while this increase was only observed in MPTP-treated monkeys in the RV. MB-COMT analysis showed a very significant increase of this isoform in the LV of MPTP- and MPTP+L-DOPA-treated animals. However, we found no significant differences in S-COMT levels. These data suggest that MB-COMT is the main isoform implicated in the cardiac noradrenergic changes observed after MPTP treatment, suggesting an increase in NA metabolism. Moreover, the increase of TH activity indicates that cardiac noradrenergic neurons still respond despite MPTP treatment. Conclusions: These results could help to elucidate the possible role of alterations in the catecholaminergic system that can contribute to noradrenergic deficiency in the hearts of PD patients. Therefore, this information might be relevant to clinical field, contributing to the therapeutic design of the disease.

The mechanistic role of thymoquinone in Parkinson's disease: focus on neuroprotection in pre-clinical studies

2021 ◽  
Vol 14 ◽  
Author(s):  
Mohammad Najim Uddin ◽  
Mohammad Injamul Hoq ◽  
Israt Jahan ◽  
Shafayet Ahmed Siddiqui ◽  
Chayan Dhar Clinton ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Clinical Studies ◽  
Nigella Sativa ◽  
Biological Effects ◽  
Neuroprotective Activity ◽  
Substantia Nigra Pars Compacta ◽  
Movement Difficulties

: Thymoquinone (TQ) is one of the leading phytochemicals, which is abundantly found in Nigella sativa L. seeds. TQ exhibited various biological effects such as antioxidant, anti-inflammatory, antimicrobial, and anti-tumoral in several pre-clinical studies. Parkinson's disease (PD) is a long-term neurodegenerative disease with movement difficulties, and the common feature of neurodegeneration in PD patients is caused by dopaminergic neural damage in the substantia nigra pars compacta. The neuroprotective activity of TQ has been studied in various neurological disorders. TQ-mediated neuroprotection against PD yet to be reported in a single frame; therefore, this review is intended to narrate the potentiality of TQ in the therapy of PD. TQ has been shown to protect against neurotoxins via amelioration of neuroinflammation, oxidative stress, apoptosis, thereby protects neurodegeneration in PD models. TQ could be an emerging therapeutic intervention in PD management, but mechanistic studies have been remained to be investigated to clarify its neuroprotective role.

scholarly journals Parkinson’s Disease and the COVID-19 Pandemic

2021 ◽  
pp. 1-14
Author(s):  
Conor Fearon ◽  
Alfonso Fasano
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Indirect Effects ◽  
Mortality Data ◽  
Contributing Factors ◽  
Scientific Rigor ◽  
The Impact ◽  
The Relationship ◽  
Non Motor Symptoms ◽  
Convincing Data

Studies focusing on the relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), coronavirus disease 2019 (COVID-19), and Parkinson’s disease (PD) have provided conflicting results. We review the literature to investigate: 1) Are PD patients at higher risk for contracting COVID-19 and are there specific contributing factors to that risk? 2) How does COVID-19 affect PD symptoms? 3) How does COVID-19 present in PD patients? 4) What are the outcomes in PD patients who contract COVID-19? 5) What is the impact of COVID-19 on PD care? 6) Does COVID-19 increase the risk of developing PD? A literature search was performed from 1979 to 2020 using the terms: ‘Parkinson’s disease’ and ‘parkinsonism’ combined with: ‘COVID-19’; ‘SARS-CoV-2’ and ‘coronavirus’. It does not appear that PD is a specific risk factor for COVID-19. There is evidence for direct/indirect effects of SARS-CoV-2 on motor/non-motor symptoms of PD. Although many PD patients present with typical COVID-19 symptoms, some present atypically with isolated worsening of parkinsonian symptoms, requiring increased anti-PD therapy and having worse outcomes. Mortality data on PD patients with COVID-19 is inconclusive (ranging from 5.2%to 100%). Patients with advanced PD appear to be particularly vulnerable. Single cases of acute hypokinetic-rigid syndrome have been described but no other convincing data has been reported. The rapidity with which COVID-19 has swept across the globe has favored the proliferation of studies which lack scientific rigor and the PD literature has not been immune. A coordinated effort is required to assimilate data and answer these questions in larger PD cohorts.

Parkinson's Disease Genetics and Pathophysiology

2021 ◽  
Vol 44 (1) ◽  
pp. 87-108
Author(s):  
Gabriel E. Vázquez-Vélez ◽  
Huda Y. Zoghbi
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Genetic Variants ◽  
Neurodegenerative Disorder ◽  
Disease Risk ◽  
Lewy Bodies ◽  
Substantia Nigra Pars Compacta ◽  
Disease Modifying ◽  
Common Neurodegenerative Disorder

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by degeneration of the substantia nigra pars compacta and by accumulation of α-synuclein in Lewy bodies. PD is caused by a combination of environmental factors and genetic variants. These variants range from highly penetrant Mendelian alleles to alleles that only modestly increase disease risk. Here, we review what is known about the genetics of PD. We also describe how PD genetics have solidified the role of endosomal, lysosomal, and mitochondrial dysfunction in PD pathophysiology. Finally, we highlight how all three pathways are affected by α-synuclein and how this knowledge may be harnessed for the development of disease-modifying therapeutics.

scholarly journals Impact of Aging on the 6-OHDA-Induced Rat Model of Parkinson’s Disease

2020 ◽  
Vol 21 (10) ◽  
pp. 3459 ◽  
Author(s):  
Sandra Barata-Antunes ◽  
Fábio G. Teixeira ◽  
Bárbara Mendes-Pinheiro ◽  
Ana V. Domingues ◽  
Helena Vilaça-Faria ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Animal Welfare ◽  
Neurodegenerative Disorder ◽  
Negative Impact ◽  
Substantia Nigra Pars Compacta ◽  
Nigrostriatal Pathway ◽  
Aged Rats ◽  
Age Related ◽  
The Impact

Parkinson’s disease (PD) is the second most common age-related neurodegenerative disorder. The neurodegeneration leading to incapacitating motor abnormalities mainly occurs in the nigrostriatal pathway due to the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Several animal models have been developed not only to better understand the mechanisms underlying neurodegeneration but also to test the potential of emerging disease-modifying therapies. However, despite aging being the main risk factor for developing idiopathic PD, most of the studies do not use aged animals. Therefore, this study aimed at assessing the effect of aging in the unilateral 6-hydroxydopamine (6-OHDA)-induced animal model of PD. For this, female young adult and aged rats received a unilateral injection of 6-OHDA into the medial forebrain bundle. Subsequently, the impact of aging on 6-OHDA-induced effects on animal welfare, motor performance, and nigrostriatal integrity were assessed. The results showed that aging had a negative impact on animal welfare after surgery. Furthermore, 6-OHDA-induced impairments on skilled motor function were significantly higher in aged rats when compared with their younger counterparts. Nigrostriatal histological analysis further revealed an increased 6-OHDA-induced dopaminergic cell loss in the SNpc of aged animals when compared to young animals. Overall, our results demonstrate a higher susceptibility of aged animals to 6-OHDA toxic insult.

scholarly journals Iron Redox Chemistry and Implications in the Parkinson’s Disease Brain

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Dinendra L. Abeyawardhane ◽  
Heather R. Lucas
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Iron Homeostasis ◽  
Substantia Nigra Pars Compacta ◽  
Biochemical Alterations ◽  
Redox Active ◽  
Cellular Inclusions ◽  
Iron Redox ◽  
Presynaptic Protein

The etiology of Parkinson’s disease (PD) is linked with cellular inclusions in the substantia nigra pars compacta region of the brain that are enriched in the misfolded presynaptic protein α-synuclein (αS) and death of the dopaminergic neurons. Brain iron homeostasis governs both neurotransmission and neurodegeneration; hence, the role of iron in PD progression and neuronal health is apparent. Elevated iron deposits become prevalent in the cerebral region upon aging and even more so in the PD brain. Structural as well as oxidative modifications can result from coordination of αS with redox active iron, which could have functional and/or pathological implications. In this review, we will discuss iron-mediated αS aggregation, alterations in iron metabolism, and the role of the iron-dopamine couple. Moreover, iron interactions with N-terminally acetylated αS, the physiologically relevant form of the human protein, will be addressed to shed light on the current understanding of protein dynamics and the physiological environment in the disease state. Oxidative pathways and biochemical alterations resulting from aberrant iron-induced chemistry are the principal focus of this review in order to highlight the plethora of research that has uncovered this emerging dichotomy of iron playing both functional and disruptive roles in PD pathology.

scholarly journals Astrocytic Oxidative/Nitrosative Stress Contributes to Parkinson’s Disease Pathogenesis: The Dual Role of Reactive Astrocytes

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 265 ◽  
Author(s):  
Asha Rizor ◽  
Edward Pajarillo ◽  
James Johnson ◽  
Michael Aschner ◽  
Eunsook Lee
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Nitrosative Stress ◽  
Critical Role ◽  
Substantia Nigra Pars Compacta ◽  
Environmental Toxicants ◽  
Oxidative And Nitrosative Stress ◽  
Reactive Astrogliosis ◽  
The Impact

Parkinson’s disease (PD) is the second most common neurodegenerative disease worldwide; it is characterized by dopaminergic neurodegeneration in the substantia nigra pars compacta, but its etiology is not fully understood. Astrocytes, a class of glial cells in the central nervous system (CNS), provide critical structural and metabolic support to neurons, but growing evidence reveals that astrocytic oxidative and nitrosative stress contributes to PD pathogenesis. As astrocytes play a critical role in the production of antioxidants and the detoxification of reactive oxygen and nitrogen species (ROS/RNS), astrocytic oxidative/nitrosative stress has emerged as a critical mediator of the etiology of PD. Cellular stress and inflammation induce reactive astrogliosis, which initiates the production of astrocytic ROS/RNS and may lead to oxidative/nitrosative stress and PD pathogenesis. Although the cause of aberrant reactive astrogliosis is unknown, gene mutations and environmental toxicants may also contribute to astrocytic oxidative/nitrosative stress. In this review, we briefly discuss the physiological functions of astrocytes and the role of astrocytic oxidative/nitrosative stress in PD pathogenesis. Additionally, we examine the impact of PD-related genes such as α-synuclein, protein deglycase DJ-1( DJ-1), Parkin, and PTEN-induced kinase 1 (PINK1) on astrocytic function, and highlight the impact of environmental toxicants, such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), rotenone, manganese, and paraquat, on astrocytic oxidative/nitrosative stress in experimental models.

scholarly journals Emerging regenerative medicine and tissue engineering strategies for Parkinson’s disease

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
James P. Harris ◽  
Justin C. Burrell ◽  
Laura A. Struzyna ◽  
H. Isaac Chen ◽  
Mijail D. Serruya ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Regenerative Medicine ◽  
Treatment Strategies ◽  
Current Treatment ◽  
Substantia Nigra Pars Compacta ◽  
Patient Specific ◽  
Motor Deficits ◽  
Nigrostriatal Pathway ◽  
Future Challenges

AbstractParkinson’s disease (PD) is the second most common progressive neurodegenerative disease, affecting 1–2% of people over 65. The classic motor symptoms of PD result from selective degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc), resulting in a loss of their long axonal projections to the striatum. Current treatment strategies such as dopamine replacement and deep brain stimulation (DBS) can only minimize the symptoms of nigrostriatal degeneration, not directly replace the lost pathway. Regenerative medicine-based solutions are being aggressively pursued with the goal of restoring dopamine levels in the striatum, with several emerging techniques attempting to reconstruct the entire nigrostriatal pathway—a key goal to recreate feedback pathways to ensure proper dopamine regulation. Although many pharmacological, genetic, and optogenetic treatments are being developed, this article focuses on the evolution of transplant therapies for the treatment of PD, including fetal grafts, cell-based implants, and more recent tissue-engineered constructs. Attention is given to cell/tissue sources, efficacy to date, and future challenges that must be overcome to enable robust translation into clinical use. Emerging regenerative medicine therapies are being developed using neurons derived from autologous stem cells, enabling the construction of patient-specific constructs tailored to their particular extent of degeneration. In the upcoming era of restorative neurosurgery, such constructs may directly replace SNpc neurons, restore axon-based dopaminergic inputs to the striatum, and ameliorate motor deficits. These solutions may provide a transformative and scalable solution to permanently replace lost neuroanatomy and improve the lives of millions of people afflicted by PD.

scholarly journals Chaperone-Mediated Autophagy and Mitochondrial Homeostasis in Parkinson’s Disease

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Ruixin Yang ◽  
Guodong Gao ◽  
Zixu Mao ◽  
Qian Yang
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neurodegenerative Disorder ◽  
Lewy Bodies ◽  
Substantia Nigra Pars Compacta ◽  
Mitochondrial Homeostasis ◽  
New Findings ◽  
Novel Therapeutic Strategies ◽  
Chaperone Mediated Autophagy

Parkinson’s disease (PD), a complex neurodegenerative disorder, is pathologically characterized by the formation of Lewy bodies and loss of dopaminergic neurons in the substantia nigra pars compacta (SNc). Mitochondrial dysfunction is considered to be one of the most important causative mechanisms. In addition, dysfunction of chaperone-mediated autophagy (CMA), one of the lysosomal proteolytic pathways, has been shown to play an important role in the pathogenesis of PD. An exciting and important development is recent finding that CMA and mitochondrial quality control may be linked. This review summarizes the studies revealing the link between autophagy and mitochondrial function. Discussions are focused on the connections between CMA and mitochondrial failure and on the role of MEF2D, a neuronal survival factor, in mediating the regulation of mitochondria in the context of CMA. These new findings highlight the need to further explore the possibility of targeting the MEF2D-mitochondria-CMA network in both understanding the PD pathogenesis and developing novel therapeutic strategies.

Sign in / Sign up

Export Citation Format

Share Document