scholarly journals UNC5C Receptor Proteolytic Cleavage by Active AEP Promotes Dopaminergic Neuronal Degeneration in Parkinson's Disease

2022 ◽  
pp. 2103396
Author(s):  
Guiqin Chen ◽  
Eun Hee Ahn ◽  
Seong Su Kang ◽  
Yiyuan Xia ◽  
Xia Liu ◽  
...  

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.


2019 ◽  
Author(s):  
Minhong Huang ◽  
Dan Lou ◽  
Adhithiya Charli ◽  
Dehui Kong ◽  
Huajun Jin ◽  
...  

AbstractGenetic mutations explain only 10-15% of cases of Parkinson’s disease (PD), while an overriding environmental component has been implicated in the etiopathogenesis of PD. But regardless of where the underlying triggers for the onset of familial and sporadic PD fall on the gene-environment axis, mitochondrial dysfunction emerges as a common mediator of dopaminergic neuronal degeneration. Herein, we employ a multidisciplinary approach to convincingly demonstrate that neurotoxicant exposure- and genetic mutation-driven mitochondrial dysfunction share a common mechanism of epigenetic dysregulation. Under both scenarios, lysine 27 acetylation of likely variant H3.2 (H3.2K27ac) increased in dopaminergic neuronal models of PD, thereby opening that region to active enhancer activity via H3K27 hyperacetylation. These vulnerable epigenomic loci represent potential transcription factor motifs for PD pathogenesis. We further confirmed the mitochondrial dysfunction induced H3K27ac during neurodegeneration in ex vivo models of PD. Our results reveal an exciting axis of ‘exposure/mutation-mitochondrial dysfunction-metabolism-H3K27ac-transcriptome’ for PD pathogenesis. Collectively, the novel mechanistic insights presented here interlinks mitochondrial dysfunction to epigenetic transcriptional regulation in dopaminergic degeneration as well as offer potential new epigenetic intervention strategies for PD.


2020 ◽  
Author(s):  
Zerrin Karaaslan ◽  
Ozlem Timirci Kahraman ◽  
Elif Sanli ◽  
Hayriye Arzu Ergen ◽  
Basar Bilgic ◽  
...  

Abstract Background: Our aim was to identify the differentially expressed genes (DEGs) between Parkinson’s disease (PD) patients and controls by microarray technology and analysis of related molecular pathways by functional annotation. Methods: Thirty PD patients and 30 controls were enrolled. Agilent Human 8X60 K Oligo Microarray was used for gene level expression identification. Gene ontology and pathway enrichment analyses were used for functional annotation of DEGs. Protein-protein interaction analyses were performed with STRING. Expression levels of randomly selected 5 genes among DEGs were quantified by real time quantitative polymerase chain reaction (RT-PCR) for validation. Flow cytometry was done to determine frequency of regulatory T cells (Tregs) in peripheral blood mononuclear cells. Results: A total of 361 DEGs (143 upregulated and 218 downregulated) were identified after GeneSpring analysis. DEGs were involved in 28 biological processes, 12 cellular components and 26 molecular functions. Pathway analyses demonstrated that upregulated genes mainly enriched in p53 (CASP3, TSC2, ATR, MDM4, CCNG1) and PI3K/Akt (IL2RA, IL4R, TSC2, VEGFA, PKN2, PIK3CA, ITGA4, BCL2L11) signaling pathways. TP53 and PIK3CA were identified as most significant hub proteins. Expression profiles obtained by RT-PCR were consistent with microarray findings. PD patients showed increased proportions of CD49d+ Tregs, which correlated with disability scores. Discussion: Survival pathway genes were upregulated putatively to compensate neuronal degeneration. Bioinformatics analysis showed an association between survival and inflammation genes. Increased CD49d+ Treg ratios might signify the attempt of the immune system to suppress ongoing inflammation. Conclusion: Altered functions of Tregs might have an important role in PD pathogenesis and CD49d expression could be a prognostic biomarker of PD.


2012 ◽  
Vol 3 (2) ◽  
Author(s):  
Kurt Jellinger

AbstractGenetic, neuropathological and biochemical evidence implicates α-synuclein, a 140 amino acid presynaptic neuronal protein, in the pathogenesis of Parkinson’s disease and other neurodegenerative disorders. The aggregated protein inclusions mainly containing aberrant α-synuclein are widely accepted as morphological hallmarks of α-synucleinopathies, but their composition and location vary between disorders along with neuronal networks affected. α-Synuclein exists physiologically in both soluble and membran-bound states, in unstructured and α-helical conformations, respectively, while posttranslational modifications due to proteostatic deficits are involved in β-pleated aggregation resulting in formation of typical inclusions. The physiological function of α-synuclein and its role linked to neurodegeneration, however, are incompletely understood. Soluble oligomeric, not fully fibrillar α-synuclein is thought to be neurotoxic, main targets might be the synapse, axons and glia. The effects of aberrant α-synuclein include alterations of calcium homeostasis, mitochondrial dysfunction, oxidative and nitric injuries, cytoskeletal effects, and neuroinflammation. Proteasomal dysfunction might be a common mechanism in the pathogenesis of neuronal degeneration in α-synucleinopathies. However, how α-synuclein induces neurodegeneration remains elusive as its physiological function. Genome wide association studies demonstrated the important role for genetic variants of the SNCA gene encoding α-synuclein in the etiology of Parkinson’s disease, possibly through effects on oxidation, mitochondria, autophagy, and lysosomal function. The neuropathology of synucleinopathies and the role of α-synuclein as a potential biomarker are briefly summarized. Although animal models provided new insights into the pathogenesis of Parkinson disease and multiple system atrophy, most of them do not adequately reproduce the cardinal features of these disorders. Emerging evidence, in addition to synergistic interactions of α-synuclein with various pathogenic proteins, suggests that prionlike induction and seeding of α-synuclein could lead to the spread of the pathology and disease progression. Intervention in the early aggregation pathway, aberrant cellular effects, or secretion of α-synuclein might be targets for neuroprotection and disease-modifying therapy.


2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Daniel Enterría-Morales ◽  
Natalia López-González del Rey ◽  
Javier Blesa ◽  
Ivette López-López ◽  
Sarah Gallet ◽  
...  

Abstract Administration of recombinant glial cell line-derived neurotrophic factor into the putamen has been tested in preclinical and clinical studies to evaluate its neuroprotective effects on the progressive dopaminergic neuronal degeneration that characterizes Parkinson’s disease. However, intracerebral glial cell line-derived neurotrophic factor infusion is a challenging therapeutic strategy, with numerous potential technical and medical limitations. Most of these limitations could be avoided if the production of endogenous glial cell line-derived neurotrophic factor could be increased. Glial cell line-derived neurotrophic factor is naturally produced in the striatum from where it exerts a trophic action on the nigrostriatal dopaminergic pathway. Most of striatal glial cell line-derived neurotrophic factor is synthesized by a subset of GABAergic interneurons characterized by the expression of parvalbumin. We sought to identify molecular targets specific to those neurons and which are putatively associated with glial cell line-derived neurotrophic factor synthesis. To this end, the transcriptomic differences between glial cell line-derived neurotrophic factor-positive parvalbumin neurons in the striatum and parvalbumin neurons located in the nearby cortex, which do not express glial cell line-derived neurotrophic factor, were analysed. Using mouse reporter models, we have defined the genomic signature of striatal parvalbumin interneurons obtained by fluorescence-activated cell sorting followed by microarray comparison. Short-listed genes were validated by additional histological and molecular analyses. These genes code for membrane receptors (Kit, Gpr83, Tacr1, Tacr3, Mc3r), cytosolic proteins (Pde3a, Crabp1, Rarres2, Moxd1) and a transcription factor (Lhx8). We also found the proto-oncogene cKit to be highly specific of parvalbumin interneurons in the non-human primate striatum, thus highlighting a conserved expression between species and suggesting that specific genes identified in mouse parvalbumin neurons could be putative targets in the human brain. Pharmacological stimulation of four G-protein-coupled receptors enriched in the striatal parvalbumin interneurons inhibited Gdnf expression presumably by decreasing cyclic adenosine monophosphate formation. Additional experiments with pharmacological modulators of adenylyl cyclase and protein kinase A indicated that this pathway is a relevant intracellular route to induce Gdnf gene activation. This preclinical study is an important step in the ongoing development of a specific pro-endo-glial cell line-derived neurotrophic factor pharmacological strategy to treat Parkinson’s disease.


2019 ◽  
Vol 121 (5) ◽  
pp. 1856-1864 ◽  
Author(s):  
Cecilia Bove ◽  
R. Alberto Travagli

Parkinson’s disease (PD) is predominantly idiopathic in origin, and a large body of evidence indicates that gastrointestinal (GI) dysfunctions are a significant comorbid clinical feature; these dysfunctions include dysphagia, nausea, delayed gastric emptying, and severe constipation, all of which occur commonly before the onset of the well-known motor symptoms of PD. Based on a distinct distribution pattern of Lewy bodies (LB) in the enteric nervous system (ENS) and in the preganglionic neurons of the dorsal motor nucleus of the vagus (DMV), and together with the early onset of GI symptoms, it was suggested that idiopathic PD begins in the ENS and spreads to the central nervous system (CNS), reaching the DMV and the substantia nigra pars compacta (SNpc). These two areas are connected by a recently discovered monosynaptic nigro-vagal pathway, which is dysfunctional in rodent models of PD. An alternative hypothesis downplays the role of LB transport through the vagus nerve and proposes that PD pathology is governed by regional or cell-restricted factors as the leading cause of nigral neuronal degeneration. The purpose of this brief review is to summarize the neuronal electrophysiological findings in the SNpc and DMV in PD.


Sign in / Sign up

Export Citation Format

Share Document