Cellular reprogramming: a new approach to modelling Parkinson's disease

2012 ◽  
Vol 40 (5) ◽  
pp. 1152-1157 ◽  
Author(s):  
Elizabeth M. Hartfield ◽  
Hugo J.R. Fernandes ◽  
Jane Vowles ◽  
Sally A. Cowley ◽  
Richard Wade-Martins
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Cell Model ◽  
Cell Types ◽  
Cellular Reprogramming ◽  
Specific Cell ◽  
Cell Type ◽  
Disease Associated Genes ◽  
Induced Pluripotent

iPSCs (induced pluripotent stem cells) offer an unparalleled opportunity to generate and study physiologically relevant cell types in culture. iPSCs can be generated by reprogramming almost any somatic cell type using pluripotency factors such as Oct4, SOX2, Nanog and Klf4. By reprogramming cells from patients carrying disease-associated mutations, and subsequent differentiation into the cell type of interest, researchers now have the opportunity to study disease-specific cell types which were previously inaccessible. In the case of PD (Parkinson's disease), reprogramming is advancing rapidly, and cell lines have been generated from patients carrying mutations in several disease-associated genes, including SNCA (α-synuclein), PARK2 (parkin), PINK1 (phosphatase and tensin homologue deleted on chromosome 10-induced putative kinase 1), PARK7 (DJ-1) and LRRK2 (leucine-rich repeat kinase 2), as well as idiopathic cases. Functional dopaminergic neurons have been differentiated from these cells and their physiology has been compared with control neurons. Human dopaminergic neurons had been previously inaccessible until post-mortem, when the disease is generally highly progressed into pathology. In comparison, iPSCs provide a living cell model with the potential to study early molecular changes which accumulate in cells and ultimately result in neurodegeneration. Although clear phenotypes have not yet been unambiguously identified in patient-derived dopaminergic neurons, there are suggested aberrations in cellular pathways involved in neurodegeneration. Overall, these cells offer a unique opportunity to study dopaminergic neurons carrying a ‘Parkinsonian genome’. The present review discusses the advances in cellular reprogramming technologies and studies that have been carried out on PD-derived iPSCs and differentiated dopaminergic neurons.

scholarly journals Epigenetic reprogramming of cell identity: lessons from development for regenerative medicine

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Amitava Basu ◽  
Vijay K. Tiwari
Keyword(s):  
Regenerative Medicine ◽  
Cell Types ◽  
Direct Conversion ◽  
Cellular Reprogramming ◽  
Specific Cell ◽  
Cell Type ◽  
Pathological Conditions ◽  
Gene Regulatory ◽  
Induced Pluripotent ◽  
And Function

AbstractEpigenetic mechanisms are known to define cell-type identity and function. Hence, reprogramming of one cell type into another essentially requires a rewiring of the underlying epigenome. Cellular reprogramming can convert somatic cells to induced pluripotent stem cells (iPSCs) that can be directed to differentiate to specific cell types. Trans-differentiation or direct reprogramming, on the other hand, involves the direct conversion of one cell type into another. In this review, we highlight how gene regulatory mechanisms identified to be critical for developmental processes were successfully used for cellular reprogramming of various cell types. We also discuss how the therapeutic use of the reprogrammed cells is beginning to revolutionize the field of regenerative medicine particularly in the repair and regeneration of damaged tissue and organs arising from pathological conditions or accidents. Lastly, we highlight some key challenges hindering the application of cellular reprogramming for therapeutic purposes.

scholarly journals Moving beyond neurons: the role of cell type-specific gene regulation in Parkinson’s disease heritability

2018 ◽  
Author(s):  
Regina H Reynolds ◽  
Juan Botía ◽  
Mike A Nalls ◽  
John Hardy ◽  
Sarah A Gagliano ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Types ◽  
Brain Regions ◽  
Brain Cell ◽  
Specific Gene ◽  
Specific Cell ◽  
Cell Type ◽  
Related Cell ◽  
Cell Type Specific

AbstractParkinson’s disease (PD), with its characteristic loss of nigrostriatal dopaminergic neurons and deposition of α-synuclein in neurons, is often considered a neuronal disorder. However, in recent years substantial evidence has emerged to implicate glial cell types, such as astrocytes and microglia. In this study, we used stratified LD score regression and expression-weighted cell-type enrichment together with several brain-related and cell-type-specific genomic annotations to connect human genomic PD findings to specific brain cell types. We found that PD heritability does not enrich in global and regional brain annotations or brain-related cell-type-specific annotations. Likewise, we found no enrichment of PD susceptibility genes in brain-related cell types. In contrast, we demonstrated a significant enrichment of PD heritability in a curated lysosomal gene set specifically expressed in astrocytic and microglial subtypes. Our results suggest that PD risk loci do not lie in specific cell types or individual brain regions, but rather in global cellular processes to which cell types may have varying vulnerability.

scholarly journals Stem Cell Therapy: A Promising Treatment of Parkinson’s Diseases

2021 ◽  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Disease Progression ◽  
Dopaminergic Neurons ◽  
Cellular Therapy ◽  
Neurodegenerative Disorder ◽  
Neuronal Degeneration ◽  
Cell Types ◽  
Parkinson’S Diseases ◽  
Multipotent Mesenchymal Stem Cells

The neurodegenerative disorder is a prolonged persistence curse and effect on economic and physical challenges in an aging world. Parkinson has come in the second category of disability disorders and associated with progressive dopaminergic neuronal degeneration with severe motor complications. It is an observation that gradual disease progression causes 70% degeneration of striatal dopaminergic neurons. Globally there are around 7-10 million patients with Parkinson's disease, however, there are huge efforts for therapeutic improvement. According to studies, no single molecular pathway was pointed out as a single etiology to control disease progression due to a lack of targeted therapeutic strategies. Previously implemented symptomatic treatments include L-dopa (L-3,4-dihydroxyphenylalanine), deep brain stimulation, and the surgical insertion of a medical device. This leads to dyskinesia, dystonia and a higher risk of major surgical complications respectively. However, not all the above-mentioned therapies cannot regenerate the dopaminergic neurons in Parkinson’s disease patients. Recent advances in the field of cellular therapy have shown promising outcomes by differentiation of multipotent mesenchymal stem cells into dopaminergic neurons under the influence of a regenerative substance. In this review, we have discussed the differentiation of dopaminergic neurons by using different cell types that can be used as a cellular therapeutic approach for Parkinson’s disease. The information was collected through a comprehensive search using the keywords, “Parkinson Disease, Dopamine, Brain derived neurotrophic factor and neuron from reliable search engines, PubMed, Google Scholar and Medline reviews from the year 2010 to 2020.

scholarly journals Heritability enrichment implicates microglia in Parkinson’s disease pathogenesis

2020 ◽  
Author(s):  
Maren Stolp Andersen ◽  
Sara Bandres-Ciga ◽  
Regina H. Reynolds ◽  
John Hardy ◽  
Mina Ryten ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Disease Risk ◽  
Association Studies ◽  
Cell Types ◽  
Polygenic Risk Score ◽  
Open Chromatin ◽  
Specific Cell ◽  
Genome Wide Association Studies ◽  
Therapeutic Implications

AbstractObjectiveUnderstanding how different parts of the immune system contribute to pathogenesis in Parkinson’s disease is a burning challenge with important therapeutic implications. We studied enrichment of common variant heritability for Parkinson’s disease stratified by immune and brain cell types.MethodsWe used summary statistics from the most recent meta-analysis of genome-wide association studies in Parkinson’s disease and partitioned heritability using linkage disequilibrium score regression, stratified for specific cell types as defined by open chromatin regions. We also validated enrichment results using a polygenic risk score approach and intersected disease-associated variants with epigenetic data and expression quantitative loci to nominate and explore a putative microglial locus.ResultsWe found significant enrichment of Parkinson’s disease risk heritability in open chromatin regions of microglia and monocytes. Genomic annotations overlapped substantially between these two cell types, and only the enrichment signal for microglia remained significant in a joint model. We present evidence suggesting P2RY12, a key microglial gene and target for the anti-thrombotic agent clopidogrel, as the likely driver of a significant Parkinson’s disease association signal on chromosome 3.InterpretationOur results provide further support for the importance of immune mechanisms in PD pathogenesis, highlight microglial dysregulation as a contributing etiological factor and nominate a targetable microglial gene candidate as a pathogenic player. Immune processes can be modulated by therapy, with potentially important clinical implications for future treatment in Parkinson’s disease.

scholarly journals Artemisinin Attenuated Oxidative Stress and Apoptosis by Inhibiting Autophagy in MPP+-treated SH-SY5Y Cell 

2020 ◽  
Author(s):  
Junqiang Yan ◽  
Hongxia Ma ◽  
Xiaoyi Lai ◽  
Jiannan Wu ◽  
Anran Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Artemisia Annua ◽  
Cell Model ◽  
Neuroprotective Effect ◽  
Critical Role ◽  
Neuroprotective Effects ◽  
Pre Treatment

Abstract Background Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's. The drugs currently used to treat PD cannot inhibit the development of PD, and long-term use produces severe drug resistance and adverse reaction. Artemisinin (ART) is an active ingredient of Artemisia annua and has a neuroprotective effect, but the mechanism is still unclear. This study was designed to investigate the neuroprotective effect of ART in MPP+-treated SH-SY5Y cells. Results There was no significant cytotoxicity when the ART concentration was under. 40μM. The 20μM ART for 24h could increase the cell viability by reducing oxidative stress and cell apoptosis in MPP+-treated SH-SY5Y cell. In addition, immunoblot and immunofluorescence results showed that MPP+ treatment increased the expression of Beclin1, LC3II/LC3I and decreased the expression of P62, while ART can reverse the changes caused by MPP+. Discussion More and more researches reported that ART and its derivates have neuroprotective effects through anti-oxidant and anti-apoptosis. we found that pre-treated cells with 20μM ART for 4h could significantly increase the viability in Parkinson's disease cell model. The oxidative stress and apoptosis were the main reason for the degeneration of dopaminergic neurons, while artemisinin can attenuate oxidative stress and apoptosis in MPP+-lesioned dopaminergic neurons. The levels of autophagy proteins LC3II/I, Beclin1 and P62 also showed that MPP+ increased the autophagy level, and pre-treatment with ART decreased the autophagy level, which may be the pathological mechanism for artemisinin to reduce oxidative stress damage and apoptosis. Conclusions These results indicate that ART exerts a positive effect on MPP+-treated SH-SY5Y cells in terms of anti-oxidative stress and anti-apoptosis. These effects may be related to autophagy. These findings contribute to a better understanding of the critical role of ART in PD treatment.

scholarly journals LRRK2 at Striatal Synapses: Cell-Type Specificity and Mechanistic Insights

Cells ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 169
Author(s):  
Patrick D. Skelton ◽  
Valerie Tokars ◽  
Loukia Parisiadou
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Disease Risk ◽  
Lessons Learned ◽  
Striatal Neurons ◽  
Cell Type ◽  
Cell Type Specificity ◽  
A Cell ◽  
Cell Type Specific

Mutations in leucine-rich repeat kinase 2 (LRRK2) cause Parkinson’s disease with a similar clinical presentation and progression to idiopathic Parkinson’s disease, and common variation is linked to disease risk. Recapitulation of the genotype in rodent models causes abnormal dopamine release and increases the susceptibility of dopaminergic neurons to insults, making LRRK2 a valuable model for understanding the pathobiology of Parkinson’s disease. It is also a promising druggable target with targeted therapies currently in development. LRRK2 mRNA and protein expression in the brain is highly variable across regions and cellular identities. A growing body of work has demonstrated that pathogenic LRRK2 mutations disrupt striatal synapses before the onset of overt neurodegeneration. Several substrates and interactors of LRRK2 have been identified to potentially mediate these pre-neurodegenerative changes in a cell-type-specific manner. This review discusses the effects of pathogenic LRRK2 mutations in striatal neurons, including cell-type-specific and pathway-specific alterations. It also highlights several LRRK2 effectors that could mediate the alterations to striatal function, including Rabs and protein kinase A. The lessons learned from improving our understanding of the pathogenic effects of LRRK2 mutations in striatal neurons will be applicable to both dissecting the cell-type specificity of LRRK2 function in the transcriptionally diverse subtypes of dopaminergic neurons and also increasing our understanding of basal ganglia development and biology. Finally, it will inform the development of therapeutics for Parkinson’s disease.

scholarly journals Diversity in the Regulation of Autophagy and Mitophagy: Lessons from Parkinson's Disease

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Charleen T. Chu
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Cell Types ◽  
Mitochondrial Targeting ◽  
Neuronal Function ◽  
Inner Mitochondrial Membrane ◽  
Canonical Pathways

Selective mitochondrial degradation through autophagy (mitophagy) has emerged as an important homeostatic mechanism in a variety of organisms and contexts. Complete clearance of mitochondria can be observed during normal maturation of certain mammalian cell types, and during certain forms of neuronal cell death. In recent years, autophagy dysregulation has been implicated in toxin-injured dopaminergic neurons as well as in major genetic models of Parkinson's disease (PD), includingα-synuclein, leucine-rich repeat kinase 2 (LRRK2), parkin, PTEN-induced kinase 1 (PINK1), and DJ-1. Indeed, PINK1-parkin interactions may form the basis of a mechanism by which dissipation of the inner mitochondrial membrane potential can trigger selective mitochondrial targeting for autophagy. Multiple signals are likely to exist, however, depending upon the trigger for mitophagy. Similarly, the regulation of basal or injury-induced autophagy does not always follow canonical pathways described for nutrient deprivation. Implications of this regulatory diversity are discussed in the context of neuronal function and survival. Further studies are needed to address whether alterations in autophagy regulation play a directly injurious role in PD pathogenesis, or if the observed changes reflect impaired, appropriate, or excessive autophagic responses to other forms of cellular injury.

scholarly journals Cell specific quantitative iron mapping on brain slices by immuno-µPIXE in healthy elderly and Parkinson’s disease

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
I. Friedrich ◽  
K. Reimann ◽  
S. Jankuhn ◽  
E. Kirilina ◽  
J. Stieler ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Glial Cells ◽  
Dopaminergic Neurons ◽  
Iron Concentration ◽  
Cell Types ◽  
Astroglial Cells ◽  
Cellular Iron ◽  
Iron Concentrations

AbstractIron is essential for neurons and glial cells, playing key roles in neurotransmitter synthesis, energy production and myelination. In contrast, high concentrations of free iron can be detrimental and contribute to neurodegeneration, through promotion of oxidative stress. Particularly in Parkinson’s disease (PD) changes in iron concentrations in the substantia nigra (SN) was suggested to play a key role in degeneration of dopaminergic neurons in nigrosome 1. However, the cellular iron pathways and the mechanisms of the pathogenic role of iron in PD are not well understood, mainly due to the lack of quantitative analytical techniques for iron quantification with subcellular resolution. Here, we quantified cellular iron concentrations and subcellular iron distributions in dopaminergic neurons and different types of glial cells in the SN both in brains of PD patients and in non-neurodegenerative control brains (Co). To this end, we combined spatially resolved quantitative element mapping using micro particle induced X-ray emission (µPIXE) with nickel-enhanced immunocytochemical detection of cell type-specific antigens allowing to allocate element-related signals to specific cell types. Distinct patterns of iron accumulation were observed across different cell populations. In the control (Co) SNc, oligodendroglial and astroglial cells hold the highest cellular iron concentration whereas in PD, the iron concentration was increased in most cell types in the substantia nigra except for astroglial cells and ferritin-positive oligodendroglial cells. While iron levels in astroglial cells remain unchanged, ferritin in oligodendroglial cells seems to be depleted by almost half in PD. The highest cellular iron levels in neurons were located in the cytoplasm, which might increase the source of non-chelated Fe3+, implicating a critical increase in the labile iron pool. Indeed, neuromelanin is characterised by a significantly higher loading of iron including most probable the occupancy of low-affinity iron binding sites. Quantitative trace element analysis is essential to characterise iron in oxidative processes in PD. The quantification of iron provides deeper insights into changes of cellular iron levels in PD and may contribute to the research in iron-chelating disease-modifying drugs.

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