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 Integration of functional genomics data to uncover cell type-specific pathways affected in Parkinson's disease

2021 ◽  
Author(s):  
Viola Volpato
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neurodegenerative Disorder ◽  
Disease Risk ◽  
Late Onset ◽  
Alpha Synuclein ◽  
Biological Information ◽  
Cell Type ◽  
Risk Variants ◽  
Cell Type Specific

Parkinson's disease (PD) is the second most prevalent late-onset neurodegenerative disorder worldwide after Alzheimer's disease for which available drugs only deliver temporary symptomatic relief. Loss of dopaminergic neurons (DaNs) in the substantia nigra and intracellular alpha-synuclein inclusions are the main hallmarks of the disease but the events that cause this degeneration remain uncertain. Despite cell types other than DaNs such as astrocytes, microglia and oligodendrocytes have been recently associated with the pathogenesis of PD, we still lack an in-depth characterisation of PD-affected brain regions at cell-type resolution that could help our understanding of the disease mechanisms. Nevertheless, publicly available large-scale brain-specific genomic, transcriptomic and epigenomic datasets can be further exploited to extract different layers of cell type-specific biological information for the reconstruction of cell type-specific transcriptional regulatory networks. By intersecting disease risk variants within the networks, it may be possible to study the functional role of these risk variants and their combined effects at cell type- and pathway levels, that, in turn, can facilitate the identification of key regulators involved in disease progression, which are often potential therapeutic targets.

scholarly journals Optogenetic delivery of trophic signals in a genetic model of Parkinson’s disease

2020 ◽  
Author(s):  
Álvaro Inglés-Prieto ◽  
Nikolas Furthmann ◽  
Samuel Crossman ◽  
Nina Hoyer ◽  
Meike Petersen ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Growth Factor ◽  
Tissue Repair ◽  
Genetic Model ◽  
Human Cells ◽  
Cell Type ◽  
Degenerative Disorders ◽  
Wide Range ◽  
Cell Type Specific

AbstractOptogenetics has been harnessed to shed new mechanistic light on current therapies and to develop future treatment strategies. This has been to date achieved by the correction of electrical signals in neuronal cells and neural circuits that are affected by disease. In contrast, the optogenetic delivery of trophic biochemical signals, which support cell survival and thereby may modify progression of degenerative disorders, has never been demonstrated in an animal disease model. Here, we reengineered the human and Drosophila melanogaster REarranged during Transfection (hRET and dRET) receptors to be activated by light, creating one-component optogenetic tools termed Opto-hRET and Opto-dRET. Upon blue light stimulation, these receptors robustly induced the MAPK/ERK proliferative signaling pathway in cultured cells. In PINK1B9 flies that exhibit loss of PTEN-induced putative kinase 1 (PINK1), a kinase associated with familial Parkinson’s disease (PD), light activation of Opto-dRET suppressed mitochondrial defects, tissue degeneration and behavioral deficits. In human cells with PINK1 loss-of-function, mitochondrial fragmentation was rescued using Opto-dRET via the PI3K/NF-кB pathway. Our results demonstrate that a light-activated receptor can ameliorate disease hallmarks in a genetic model of PD. The optogenetic delivery of trophic signals is cell type-specific and reversible and thus has the potential to overcome limitations of current strategies towards a spatio-temporal regulation of tissue repair.Significance StatementThe death of physiologically important cell populations underlies of a wide range of degenerative disorders, including Parkinson’s disease (PD). Two major strategies to counter cell degeneration, soluble growth factor injection and growth factor gene therapy, can lead to the undesired activation of bystander cells and non-natural permanent signaling responses. Here, we employed optogenetics to deliver cell type-specific pro-survival signals in a genetic model of PD. In Drosophila and human cells exhibiting loss of the PINK1 kinase, akin to autosomal recessive PD, we efficiently suppressed disease phenotypes using a light-activated tyrosine kinase receptor. This work demonstrates a spatio-temporally precise strategy to interfere with degeneration and may open new avenues towards tissue repair in disease models.

scholarly journals Fos and Jun repress transcription activation by NF-IL6 through association at the basic zipper region.

1994 ◽  
Vol 14 (1) ◽  
pp. 268-276 ◽  
Author(s):  
W Hsu ◽  
T K Kerppola ◽  
P L Chen ◽  
T Curran ◽  
S Chen-Kiang
Keyword(s):  
Leucine Zipper ◽  
Transcription Activation ◽  
Cell Type ◽  
Cell Type Specificity ◽  
Basic Leucine Zipper ◽  
Dna Binding Specificity ◽  
Dna Elements ◽  
A Cell ◽  
Cell Type Specific

NF-IL6 and AP-1 family transcription factors are coordinately induced by interleukin-6 (IL-6) in a cell-type-specific manner, suggesting that they mediate IL-6 signals in the nucleus. We show that the basic leucine zipper (bZIP) region of NF-IL6 mediates a direct association with the bZIP regions of Fos and Jun in vitro. This interaction does not depend on the presence of their cognate recognition DNA elements or the posttranslational modification of either partner. NF-IL6 homodimers can bind to both NF-IL6 and AP-1 sites, whereas Fos and Jun cannot bind to most NF-IL6 sites. Cross-family association with Fos or with Jun alters the DNA binding specificity of NF-IL6 and reduced its binding to NF-IL6 sites. NF-IL6 isoforms that differ in the site of translation initiation have distinct transcriptional activities. Activation of a reporter gene linked to the NF-IL6 site by NF-IL6 is repressed by Fos and by Jun in transient transfection assays. Thus, association with AP-1 results in repression of transcription activation by NF-IL6. The repression is NF-IL6 site dependent and may have a role in determining the promoter and cell type specificity in IL-6 signaling.

scholarly journals Integration of eQTL and Parkinson’s disease GWAS data implicates 11 disease genes

2019 ◽  
Author(s):  
Demis A. Kia ◽  
David Zhang ◽  
Sebastian Guelfi ◽  
Claudia Manzoni ◽  
Leon Hubbard ◽  
...  
Keyword(s):  
Gene Expression ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Candidate Genes ◽  
Gwas Data ◽  
Cell Type ◽  
Cell Type Specificity ◽  
Protein Ubiquitination ◽  
Ppi Networks ◽  
Core Proteins

AbstractSubstantial genome-wide association study (GWAS) work in Parkinson’s disease (PD) has led to an increasing number of loci shown reliably and robustly to be associated with the increased risk of the disease. Prioritising causative genes and pathways from these studies has proven problematic. Here, we present a comprehensive analysis of PD GWAS data with expression and methylation quantitative trait loci (eQTL/mQTL) using Colocalisation analysis (Coloc) and transcriptome-wide association analysis (TWAS) to uncover putative gene expression and splicing mechanisms driving PD GWAS signals. Candidate genes were further characterised by determining cell-type specificity, weighted gene co-expression (WGNCA) and protein-protein interaction (PPI) networks.Gene-level analysis of expression revealed 5 genes (WDR6, CD38, GPNMB, RAB29, TMEM163) that replicated using both Coloc and TWAS analyses in both GTEx and Braineac expression datasets. A further 6 genes (ZRANB3, PCGF3, NEK1, NUPL2, GALC, CTSB) showed evidence of disease-associated splicing effects. Cell-type specificity analysis revealed that gene expression was overall more prevalent in glial cell-types compared to neurons. The WGNCA analysis showed that NUPL2 is a key gene in 3 modules implicated in catabolic processes related with protein ubiquitination (protein ubiquitination (p=7.47e-10) and ubiquitin-dependent protein catabolic process (p = 2.57e-17) in nucleus accumbens, caudate and putamen, while TMEM163 and ZRANB3 were both important in modules indicating regulation of signalling (p=1.33e-65] and cell communication (p=7.55e-35) in the frontal cortex and caudate respectively. PPI analysis and simulations using random networks demonstrated that the candidate genes interact significantly more with known Mendelian PD and parkinsonism proteins than would be expected by chance. The proteins core proteins this network were enriched for regulation of the ERBB receptor tyrosine protein kinase signalling pathways.Together, these results point to a number of candidate genes and pathways that are driving the associations observed in PD GWAS studies.

scholarly journals Single Cell Atlas of Human Putamen Reveals Disease Specific Changes in Synucleinopathies: Parkinson's Disease and Multiple System Atrophy

2021 ◽  
Author(s):  
Rahul Pande ◽  
Yinyin Huang ◽  
Erin Teeple ◽  
Pooja Joshi ◽  
Amilcar Flores-Morales ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Multiple System Atrophy ◽  
Single Cell ◽  
Alpha Synuclein ◽  
Cell Type ◽  
Distinct Cell Type ◽  
Altered Expression ◽  
Cell Type Specific ◽  
Disease Specific

Understanding disease biology at a cellular level from disease specific tissues is imperative for effective drug development for complex neurodegenerative diseases. We profiled 87,086 nuclei from putamen tissue of healthy controls, Parkinson's Disease (PD), and Multiple System Atrophy (MSA) subjects to construct a comprehensive single cell atlas. Although both PD and MSA are manifestations of alpha-synuclein protein aggregation, we observed that both the diseases have distinct cell-type specific changes. We see a possible expansion and activation of microglia and astrocytes in PD compared to MSA and controls. Contrary to PD microglia, we found absence of upregulated unfolded protein response in MSA microglia compared to controls. Differentially expressed genes in major cell types are enriched for genes associated with PD-GWAS loci. We found altered expression of major neurodegeneration associated genes, SNCA, MAPT, LRRK2, and APP, at cell-type resolution. We also identified disease associated gene modules using a network biology approach. Overall, this study creates an interactive atlas from synucleinopathies and provides major cell-type specific disease insights.

scholarly journals Parkinson’s Disease Genetic Risk Evaluation in Microglia Highlights Autophagy and Lysosomal Genes

2020 ◽  
Author(s):  
Alix Booms ◽  
Steven E. Pierce ◽  
Gerhard A. Coetzee
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphisms ◽  
Cell Type ◽  
Genome Wide ◽  
Risk Snps ◽  
A Cell ◽  
Regulatory Dna

AbstractGenome-wide association studies (GWAS) have uncovered thousands of single nucleotide polymorphisms (SNPs) that are associated with Parkinson’s disease (PD) risk. The functions of most of these SNPs, including the cell type they influence, and how they affect PD etiology remain largely unknown. To identify functional SNPs, we aligned PD risk SNPs within active regulatory regions of DNA in microglia, a cell type implicated in PD development. Out of 6,749 ‘SNPs of interest’ from the most recent PD GWAS metanalysis, 73 were located in open regulatory chromatin as determined by both ATAC-seq and H3K27ac ChIP-seq. We highlight a subset of SNPs that are favorable candidates for further mechanistic studies. These SNPs are located in regulatory DNA at the SLC50A1, SNCA, BAG3, FBXL19, SETD1A, and NUCKS1 loci. A network analysis of the genes with risk SNPs in their promoters, implicated substance transport, involving autophagy and lysosomal genes. Our study provides a more focused set of risk SNPs and their associated risk genes as candidates for further follow-up studies, which will help identify mechanisms in microglia that increase the risk for PD.

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 Representation of spontaneous movement by dopaminergic neurons is cell-type selective and disrupted in parkinsonism

2016 ◽  
Vol 113 (15) ◽  
pp. E2180-E2188 ◽  
Author(s):  
Paul D. Dodson ◽  
Jakob K. Dreyer ◽  
Katie A. Jennings ◽  
Emilie C. J. Syed ◽  
Richard Wade-Martins ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Dopaminergic Neurons ◽  
Dopaminergic Neuron ◽  
Striatal Dopamine ◽  
Cell Type ◽  
Spontaneous Movement ◽  
Midbrain Dopaminergic Neurons ◽  
Spontaneous Movements

Midbrain dopaminergic neurons are essential for appropriate voluntary movement, as epitomized by the cardinal motor impairments arising in Parkinson’s disease. Understanding the basis of such motor control requires understanding how the firing of different types of dopaminergic neuron relates to movement and how this activity is deciphered in target structures such as the striatum. By recording and labeling individual neurons in behaving mice, we show that the representation of brief spontaneous movements in the firing of identified midbrain dopaminergic neurons is cell-type selective. Most dopaminergic neurons in the substantia nigra pars compacta (SNc), but not in ventral tegmental area or substantia nigra pars lateralis, consistently represented the onset of spontaneous movements with a pause in their firing. Computational modeling revealed that the movement-related firing of these dopaminergic neurons can manifest as rapid and robust fluctuations in striatal dopamine concentration and receptor activity. The exact nature of the movement-related signaling in the striatum depended on the type of dopaminergic neuron providing inputs, the striatal region innervated, and the type of dopamine receptor expressed by striatal neurons. Importantly, in aged mice harboring a genetic burden relevant for human Parkinson’s disease, the precise movement-related firing of SNc dopaminergic neurons and the resultant striatal dopamine signaling were lost. These data show that distinct dopaminergic cell types differentially encode spontaneous movement and elucidate how dysregulation of their firing in early Parkinsonism can impair their effector circuits.

scholarly journals Subcellular proteomics of dopamine neurons in the mouse brain reveals axonal enrichment of proteins encoded by Parkinson's disease-linked genes

2021 ◽  
Author(s):  
Benjamin D. Hobson ◽  
Se Joon Choi ◽  
Rajesh K. Soni ◽  
David Sulzer ◽  
Peter A Sims
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Mouse Brain ◽  
Dopaminergic Neurons ◽  
Cell Biology ◽  
Neuronal Cell ◽  
Cell Types ◽  
Dopamine Neurons ◽  
Cell Type Specificity ◽  
Subcellular Proteomics

Dopaminergic neurons modulate neural circuits and behaviors via dopamine release from expansive, long range axonal projections. The elaborate cytoarchitecture of these neurons is embedded within complex brain tissue, making it difficult to access the neuronal proteome using conventional methods. Here, we demonstrate APEX2 proximity labeling within genetically targeted neurons in the mouse brain, enabling subcellular proteomics with cell type-specificity. By combining APEX2 biotinylation with mass spectrometry, we mapped the somatodendritic and axonal proteomes of midbrain dopaminergic neurons. Our dataset reveals the proteomic architecture underlying proteostasis, axonal metabolism, and neurotransmission in these neurons. We find a significant enrichment of proteins encoded by Parkinson's disease-linked genes in striatal dopaminergic axons, including proteins with previously undescribed axonal localization. These proteomic datasets provide a resource for neuronal cell biology, and this approach can be readily adapted for study of other neural cell types.

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