scholarly journals A Link between Autophagy and the Pathophysiology of LRRK2 in Parkinson's Disease

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Patricia Gómez-Suaga ◽  
Elena Fdez ◽  
Marian Blanca Ramírez ◽  
Sabine Hilfiker
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Enzymatic Activity ◽  
Molecular Mechanisms ◽  
Neurodegenerative Disorder ◽  
Current Knowledge ◽  
Mutant Gene ◽  
Pathogenic Mutation ◽  
Kinase Domain ◽  
Mutant Lrrk2

Parkinson's disease is a debilitating neurodegenerative disorder, and its molecular etiopathogenesis remains poorly understood. The discovery of monogenic forms has significantly advanced our understanding of the molecular mechanisms underlying PD, as it allows generation of cellular and animal models carrying the mutant gene to define pathological pathways. Mutations in leucine-rich repeat kinase 2 (LRRK2) cause dominantly inherited PD, and variations increase risk, indicating that LRRK2 is an important player in both genetic and sporadic forms of the disease. G2019S, the most prominent pathogenic mutation, maps to the kinase domain and enhances enzymatic activity of LRRK2, which in turn seems to correlate with cytotoxicity. Since kinases are druggable targets, this has raised great hopes that disease-modifying therapies may be developed around modifying LRRK2 enzymatic activity. Apart from cytotoxicity, changes in autophagy have been consistently reported in the context of G2019S mutant LRRK2. Here, we will discuss current knowledge about mechanism(s) by which mutant LRRK2 may regulate autophagy, which highlights additional putative therapeutic targets.

scholarly journals Parkinson's disease and mitophagy: an emerging role for LRRK2

2021 ◽  
Author(s):  
Francois Singh ◽  
Ian G. Ganley
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Molecular Mechanisms ◽  
Neurodegenerative Disorder ◽  
Current Knowledge ◽  
Muscle Stiffness ◽  
Substantia Nigra Pars Compacta ◽  
Common Mutation ◽  
Common Denominator

Parkinson's disease (PD) is a progressive neurodegenerative disorder that affects around 2% of individuals over 60 years old. It is characterised by the loss of dopaminergic neurons in the substantia nigra pars compacta of the midbrain, which is thought to account for the major clinical symptoms such as tremor, slowness of movement and muscle stiffness. Its aetiology is poorly understood as the physiological and molecular mechanisms leading to this neuronal loss are currently unclear. However, mitochondrial and lysosomal dysfunction seem to play a central role in this disease. In recent years, defective mitochondrial elimination through autophagy, termed mitophagy, has emerged as a potential contributing factor to disease pathology. PINK1 and Parkin, two proteins mutated in familial PD, were found to eliminate mitochondria under distinct mitochondrial depolarisation-induced stress. However, PINK1 and Parkin are not essential for all types of mitophagy and such pathways occur in most cell types and tissues in vivo, even in the absence of overt mitochondrial stress — so-called basal mitophagy. The most common mutation in PD, that of glycine at position 2019 to serine in the protein kinase LRRK2, results in increased activity and this was recently shown to disrupt basal mitophagy in vivo. Thus, different modalities of mitophagy are affected by distinct proteins implicated in PD, suggesting impaired mitophagy may be a common denominator for the disease. In this short review, we discuss the current knowledge about the link between PD pathogenic mutations and mitophagy, with a particular focus on LRRK2.

scholarly journals Transient Receptor Potential Channels as an Emerging Target for the Treatment of Parkinson’s Disease: An Insight Into Role of Pharmacological Interventions

2020 ◽  
Vol 8 ◽  
Author(s):  
Bhupesh Vaidya ◽  
Shyam Sunder Sharma
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Molecular Mechanisms ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Neurodegenerative Disorder ◽  
Receptor Potential ◽  
Transient Receptor Potential Channels ◽  
Transient Receptor

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the symptoms of motor deficits and cognitive decline. There are a number of therapeutics available for the treatment of PD, but most of them suffer from serious side effects such as bradykinesia, dyskinesia and on-off effect. Therefore, despite the availability of these pharmacological agents, PD patients continue to have an inferior quality of life. This has warranted a need to look for alternate strategies and molecular targets. Recent evidence suggests the Transient Receptor Potential (TRP) channels could be a potential target for the management of motor and non-motor symptoms of PD. Though still in the preclinical stages, agents targeting these channels have shown immense potential in the attenuation of behavioral deficits and signaling pathways. In addition, these channels are known to be involved in the regulation of ionic homeostasis, which is disrupted in PD. Moreover, activation or inhibition of many of the TRP channels by calcium and oxidative stress has also raised the possibility of their paramount involvement in affecting the other molecular mechanisms associated with PD pathology. However, due to the paucity of information available and lack of specificity, none of these agents have gone into clinical trials for PD treatment. Considering their interaction with oxidative stress, apoptosis and excitotoxicity, TRP channels could be considered as a potential future target for the treatment of PD.

scholarly journals α-synuclein pathogenesis in hiPSC models of Parkinson’s Disease

2021 ◽  
Author(s):  
Leo R Quinlan ◽  
Jara Maria Baena-Montes ◽  
Sahar Avazzadeh
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Disease Modeling ◽  
Viral Vector ◽  
Neurodegenerative Disorder ◽  
Current Knowledge ◽  
Lewy Bodies ◽  
Model Systems ◽  
The Brain

α-synuclein is an increasingly prominent player in the pathology of a variety of neurodegenerative conditions. Parkinson’s disease (PD) is a neurodegenerative disorder that affects mainly the dopaminergic neurons in the substantia nigra of the brain. Typical of PD pathology is the finding of protein aggregations termed ‘Lewy bodies’ in the brain regions affected. α-synuclein is implicated in many disease states including dementia with Lewy bodies and Alzheimer’s disease. However, PD is the most common synucleinopathy and continues to be a significant focus of PD research in terms of the α-synuclein Lewy body pathology. Mutations in several genes are associated with PD development including SNCA, which encodes α-synuclein. A variety of model systems have been employed to study α-synuclein physiology and pathophysiology in an attempt to relate more closely to PD pathology. These models include cellular and animal system exploring transgenic technologies, viral vector expression and knockdown approaches, and models to study the potential prion protein-like effects of α-synuclein. The current review focuses on human induced pluripotent stem cell (iPSC) models with a specific focus on mutations or multiplications of the SNCA gene. iPSCs are a rapidly evolving technology with huge promise in the study of normal physiology and disease modeling in vitro. The ability to maintain a patient's genetic background and replicate similar cell phenotypes make iPSCs a powerful tool in the study of neurological diseases. This review focus on the current knowledge about α-synuclein physiological function as well as its role in PD pathogenesis based on human iPSC models.

Establishment of dopaminergic neuron purification system in mice for the Parkinson’s disease study

2021 ◽  
Author(s):  
Kit-Yeng Sheng ◽  
Hideki Hayakawa ◽  
Kousuke Baba ◽  
Yasuyoshi Kimura ◽  
Hideki Mochizuki ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Mouse Model ◽  
Protein Modification ◽  
Molecular Mechanisms ◽  
Neurodegenerative Disorder ◽  
Sequencing Analysis ◽  
Fluorescent Reporter ◽  
Fatty Acid Binding ◽  
Related Process

Abstract Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by the degeneration of dopaminergic (DA) neurons. The key neuropathological hallmarks in the brain of patients with PD are Lewy body (LB) inclusions, consisting of misfolded α-synuclein proteins. Despite extensive efforts, the molecular link between LB inclusions and DA neurodegeneration remains elusive because of the lack of a suitable approach. Here, we aimed to establish a novel dopa-decarboxylase (Ddc) fluorescent reporter mouse model that allows the identification and collection of DA neurons using a fluorescence-activated cell sorter. Successful enrichment of Ddc-expressing cells was validated by RNA-sequencing analysis. This approach allowed us to analyze the effect of α-synuclein accumulation on the DA neuron’s transcriptome prior to neurodegeneration occurrence. We found that lipid-related process genes, followed by protein modification and degradation-related process genes, were upregulated in the α-synuclein-injected DA neurons. The activation of fatty acid-binding protein 1 (Fabp1) was particularly evident and confirmed by immunohistochemistry. Thus, our mouse model system and datasets provide a new method and insights into molecular mechanisms in PD.

scholarly journals Genetic Analysis ofPARK2andPINK1Genes in Brazilian Patients with Early-Onset Parkinson's Disease

2013 ◽  
Vol 35 ◽  
pp. 181-185 ◽  
Author(s):  
Karla Cristina Vasconcelos Moura ◽  
Mário Campos Junior ◽  
Ana Lúcia Zuma de Rosso ◽  
Denise Hack Nicaretta ◽  
João Santos Pereira ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Early Onset ◽  
Neurodegenerative Disorder ◽  
Point Mutations ◽  
Pathogenic Mutation ◽  
Missense Variants ◽  
Pathogenic Variants ◽  
Gene Environment ◽  
Early Onset Parkinson’S Disease

Parkinson's disease is the second most frequent neurodegenerative disorder in the world, affecting 1-2% of individuals over the age of 65. The etiology of Parkinson's disease is complex, with the involvement of gene-environment interactions. Although it is considered a disease of late manifestation, early-onset forms of parkinsonism contribute to 5–10% of all cases. In the present study, we screened mutations in coding regions ofPARK2andPINK1genes in 136 unrelated Brazilian patients with early-onset Parkinson's disease through automatic sequencing. We identified six missense variants inPARK2gene: one known pathogenic mutation, two variants of uncertain role, and three nonpathogenic changes. No pathogenic mutation was identified inPINK1gene, only benign polymorphisms. All putative pathogenic variants found in this study were in heterozygous state. Our data show thatPARK2point mutations are more common in Brazilian early-onset Parkinson's disease patients (2.9%) thanPINK1missense variants (0%), corroborating other studies worldwide.

scholarly journals Prioritization of candidate genes for a South African family with Parkinson’s disease using in-silico tools

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0249324
Author(s):  
Boiketlo Sebate ◽  
Katelyn Cuttler ◽  
Ruben Cloete ◽  
Marcell Britz ◽  
Alan Christoffels ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
South African ◽  
Neurodegenerative Disorder ◽  
3D Structure ◽  
Three Dimensional ◽  
Pathogenic Mutation ◽  
Mendelian Inheritance ◽  
Model Quality ◽  
High Flexibility

Parkinson’s disease (PD) is a neurodegenerative disorder exhibiting Mendelian inheritance in some families. Next-generation sequencing approaches, including whole exome sequencing (WES), have revolutionized the field of Mendelian disorders and have identified a number of PD genes. We recruited a South African family with autosomal dominant PD and used WES to identify a possible pathogenic mutation. After filtration and prioritization, we found five potential causative variants in CFAP65, RTF1, NRXN2, TEP1 and CCNF. The variant in NRXN2 was selected for further analysis based on consistent prediction of deleteriousness across computational tools, not being present in unaffected family members, ethnic-matched controls or public databases, and its expression in the substantia nigra. A protein model for NRNX2 was created which provided a three-dimensional (3D) structure that satisfied qualitative mean and global model quality assessment scores. Trajectory analysis showed destabilizing effects of the variant on protein structure, indicated by high flexibility of the LNS-6 domain adopting an extended conformation. We also found that the known substrate N-acetyl-D-glucosamine (NAG) contributed to restoration of the structural stability of mutant NRXN2. If NRXN2 is indeed found to be the causal gene, this could reveal a new mechanism for the pathobiology of PD.

scholarly journals Alpha-synuclein levels modulate seeding and aggregation in cultured cells

2021 ◽  
Author(s):  
Eftychia Vasili ◽  
Antonio Dominguez-Meijide ◽  
Manuel Flores-León ◽  
Mohammed Al-Azzani ◽  
Angeliki Kanellidi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
Neurodegenerative Disorder ◽  
Alpha Synuclein ◽  
Lewy Neurites ◽  
Stable Cell Lines ◽  
The Impact

Abstract Background Parkinson's disease is a progressive neurodegenerative disorder characterized by the accumulation of misfolded alpha-synuclein in intraneuronal inclusions known as Lewy bodies and Lewy neurites. Multiple studies strongly implicate the levels of alpha-synuclein as a major risk factor for the onset and progression of Parkinson’s disease. alpha-Synuclein pathology spreads progressively throughout interconnected brain regions but the precise molecular mechanisms underlying alpha-synuclein spreading and accumulation remain obscure. Methods Here, using stable cell lines expressing alpha-synuclein, we examined the correlation between endogenous alpha-synuclein levels and the seeding propensity by exogenous alpha-synuclein pre-formed fibrils. We applied biochemical approaches and imaging methods in stable cell lines expressing alpha-synuclein and in primary neurons to determine the impact of alpha-synuclein expression levels on seeding and aggregation. Results Our results indicate that alpha-synuclein levels define the pattern and severity of aggregation and the extent of p-alpha-synuclein deposition, likely explaining the selective vulnerability of different cell types in synucleinopathies. Conclusions The elucidation of the cellular processes involved in the pathological aggregation of alpha-synuclein will enable the identification of novel targets and the development of therapeutic strategies for Parkinson's disease and other synucleinopathies.

scholarly journals Autophagic- and Lysosomal-Related Biomarkers for Parkinson’s Disease: Lights and Shadows

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1317 ◽  
Author(s):  
Helena Xicoy ◽  
Núria Peñuelas ◽  
Miquel Vila ◽  
Ariadna Laguna
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Molecular Mechanisms ◽  
Biomarker Discovery ◽  
Neurodegenerative Disorder ◽  
Early Stage ◽  
Functional Studies ◽  
Functional Consequences ◽  
Gba Mutations ◽  
Lysosomal Proteins

Parkinson’s disease (PD) is a neurodegenerative disorder that currently affects 1% of the population over the age of 60 years, for which no disease-modifying treatments exist. This lack of effective treatments is related to the advanced stage of neurodegeneration existing at the time of diagnosis. Thus, the identification of early stage biomarkers is crucial. Biomarker discovery is often guided by the underlying molecular mechanisms leading to the pathology. One of the central pathways deregulated during PD, supported both by genetic and functional studies, is the autophagy-lysosomal pathway. Hence, this review presents different studies on the expression and activity of autophagic and lysosomal proteins, and their functional consequences, performed in peripheral human biospecimens. Although most biomarkers are inconsistent between studies, some of them, namely HSC70 levels in sporadic PD patients, and cathepsin D levels and glucocerebrosidase activity in PD patients carrying GBA mutations, seem to be consistent. Hence, evidence exists that the impairment of the autophagy-lysosomal pathway underlying PD pathophysiology can be detected in peripheral biosamples and further tested as potential biomarkers. However, longitudinal, stratified, and standardized analyses are needed to confirm their clinical validity and utility.

scholarly journals GRP78/BIP/HSPA5 as a Therapeutic Target in Models of Parkinson’s Disease: A Mini Review

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Adaze Bijou Enogieru ◽  
Sylvester Ifeanyi Omoruyi ◽  
Donavon Charles Hiss ◽  
Okobi Eko Ekpo
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Er Stress ◽  
Neurodegenerative Disorder ◽  
Current Knowledge ◽  
Dopamine Neurons ◽  
Substantia Nigra Pars Compacta ◽  
Unfolded Protein ◽  
Folded Proteins ◽  
The Unfolded Protein Response

Parkinson’s disease (PD) is a common neurodegenerative disorder characterized by selective loss of dopamine neurons in the substantia nigra pars compacta of the midbrain. Reports from postmortem studies in the human PD brain, and experimental PD models reveal that endoplasmic reticulum (ER) stress is implicated in the pathogenesis of PD. In times of stress, the unfolded or misfolded proteins overload the folding capacity of the ER to induce a condition generally known as ER stress. During ER stress, cells activate the unfolded protein response (UPR) to handle increasing amounts of abnormal proteins, and recent evidence has demonstrated the activation of the ER chaperone GRP78/BiP (78 kDa glucose-regulated protein/binding immunoglobulin protein), which is important for proper folding of newly synthesized and partly folded proteins to maintain protein homeostasis. Although the activation of this protein is essential for the initiation of the UPR in PD, there are inconsistent reports on its expression in various PD models. Consequently, this review article aims to summarize current knowledge on neuroprotective agents targeting the expression of GRP78/BiP in the regulation of ER stress in experimental PD models.

scholarly journals Parkinson’s Disease-Related Genes and Lipid Alteration

2021 ◽  
Vol 22 (14) ◽  
pp. 7630
Author(s):  
Milena Fais ◽  
Antonio Dore ◽  
Manuela Galioto ◽  
Grazia Galleri ◽  
Claudia Crosio ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Molecular Mechanisms ◽  
Neurodegenerative Disorder ◽  
Clinical Manifestations ◽  
Alpha Synuclein ◽  
Experimental Models ◽  
Protein Clearance ◽  
Genetic And Environmental Factors

Parkinson’s disease (PD) is a complex and progressive neurodegenerative disorder with a prevalence of approximately 0.5–1% among those aged 65–70 years. Although most of its clinical manifestations are due to a loss of dopaminergic neurons, the PD etiology is largely unknown. PD is caused by a combination of genetic and environmental factors, and the exact interplay between genes and the environment is still debated. Several biological processes have been implicated in PD, including mitochondrial or lysosomal dysfunctions, alteration in protein clearance, and neuroinflammation, but a common molecular mechanism connecting the different cellular alterations remains incompletely understood. Accumulating evidence underlines a significant role of lipids in the pathological pathways leading to PD. Beside the well-described lipid alteration in idiopathic PD, this review summarizes the several lipid alterations observed in experimental models expressing PD-related genes and suggests a possible scenario in relationship to the molecular mechanisms of neuronal toxicity. PD could be considered a lipid-induced proteinopathy, where alteration in lipid composition or metabolism could induce protein alteration—for instance, alpha-synuclein accumulation—and finally neuronal death.

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