Autophagy and protein aggregation as a mechanism of dopaminergic degeneration in a primary human dopaminergic neuronal model
The pathophysiology underlying the loss of dopaminergic neurons in Parkinson’s disease (PD) is unclear. A gap of knowledge in the molecular and cellular events leading to degeneration of the nigrostriatal DA system is a major barrier to the development of effective therapies for PD. 1-methyl-4-pheny...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-01-01
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| Series: | Toxicology Reports |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214750022000750 |
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| author | Elvis Cuevas Aida Guzman Susan M. Burks Alejandro Ramirez-Lee Syed F. Ali Syed Z. Imam |
| author_facet | Elvis Cuevas Aida Guzman Susan M. Burks Alejandro Ramirez-Lee Syed F. Ali Syed Z. Imam |
| author_sort | Elvis Cuevas |
| collection | DOAJ |
| description | The pathophysiology underlying the loss of dopaminergic neurons in Parkinson’s disease (PD) is unclear. A gap of knowledge in the molecular and cellular events leading to degeneration of the nigrostriatal DA system is a major barrier to the development of effective therapies for PD. 1-methyl-4-phenylpyridinium (MPP+) is used as a reliable in vitro model of PD in dopaminergic neurons; however, the molecular mechanisms that lead to cell death with this model are not fully understood. Additionally, there is a lack of translational in vitro models to fully understand progressive dopaminergic neurotoxicity. Here, we propose cultures of primary human dopaminergic neuronal precursor cells (HDNPCs) as a model to study progressive dopaminergic toxicity and neuronal damage in PD. We evaluated the concentration-response of MPP+ (0–10 mM) at 24 h, using cell viability and mitochondrial activity assays (LDH, XTT, Live/Dead staining, and MitoTracker). Based on concentration-response data, we chose two concentrations (1.0 and 2.5 mM) of MPP+ to evaluate markers of autophagy and dopaminergic status [tyrosine hydroxylase (TH)] after a 24-h exposure. Exposure to MPP+ induced cytotoxicity, reduced cell viability, and decreased mitochondrial activity. MPP+ at 1.0 and 2.5 mM also induced expression of lysosome-associated membrane protein 1 (LAMP-1) and increased the ratio of light chain 3 (LC3), LC3BII/LC3BI. The expression of TH also decreased. Furthermore, α-synuclein (α-SYN) and parkin were evaluated by immunofluorescence (IF) at 1.0 and 2.5 mM MPP+ after 24 h. A qualitative analysis revealed decreased parkin expression while α-SYN aggregation was observed in the cytoplasm and the nucleus. These data suggest that in HDNPCs MPP+ can cause cytotoxicity and neuronal damage. This damage may be mediated by autophagy, dopamine synthesis, and protein aggregation. The combination of HDNPCs and MPP+ may serve as valuable in vitro model of progressive dopaminergic neurotoxicity for research into potential treatments for PD. |
| first_indexed | 2024-04-11T14:23:20Z |
| format | Article |
| id | doaj.art-659cd74f08e64897b54d3a68fe7918d1 |
| institution | Directory Open Access Journal |
| issn | 2214-7500 |
| language | English |
| last_indexed | 2024-04-11T14:23:20Z |
| publishDate | 2022-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Toxicology Reports |
| spelling | doaj.art-659cd74f08e64897b54d3a68fe7918d12022-12-22T04:19:00ZengElsevierToxicology Reports2214-75002022-01-019806813Autophagy and protein aggregation as a mechanism of dopaminergic degeneration in a primary human dopaminergic neuronal modelElvis Cuevas0Aida Guzman1Susan M. Burks2Alejandro Ramirez-Lee3Syed F. Ali4Syed Z. Imam5Division of Neurotoxicology, National Center for Toxicological Research/US Food and Drug Administration, Jefferson, AR 72079, USADivision of Neurotoxicology, National Center for Toxicological Research/US Food and Drug Administration, Jefferson, AR 72079, USADivision of Neurotoxicology, National Center for Toxicological Research/US Food and Drug Administration, Jefferson, AR 72079, USADivision of Neurotoxicology, National Center for Toxicological Research/US Food and Drug Administration, Jefferson, AR 72079, USADivision of Neurotoxicology, National Center for Toxicological Research/US Food and Drug Administration, Jefferson, AR 72079, USADivision of Neurotoxicology, National Center for Toxicological Research/US Food and Drug Administration, Jefferson, AR 72079, USA; Corresponding author.The pathophysiology underlying the loss of dopaminergic neurons in Parkinson’s disease (PD) is unclear. A gap of knowledge in the molecular and cellular events leading to degeneration of the nigrostriatal DA system is a major barrier to the development of effective therapies for PD. 1-methyl-4-phenylpyridinium (MPP+) is used as a reliable in vitro model of PD in dopaminergic neurons; however, the molecular mechanisms that lead to cell death with this model are not fully understood. Additionally, there is a lack of translational in vitro models to fully understand progressive dopaminergic neurotoxicity. Here, we propose cultures of primary human dopaminergic neuronal precursor cells (HDNPCs) as a model to study progressive dopaminergic toxicity and neuronal damage in PD. We evaluated the concentration-response of MPP+ (0–10 mM) at 24 h, using cell viability and mitochondrial activity assays (LDH, XTT, Live/Dead staining, and MitoTracker). Based on concentration-response data, we chose two concentrations (1.0 and 2.5 mM) of MPP+ to evaluate markers of autophagy and dopaminergic status [tyrosine hydroxylase (TH)] after a 24-h exposure. Exposure to MPP+ induced cytotoxicity, reduced cell viability, and decreased mitochondrial activity. MPP+ at 1.0 and 2.5 mM also induced expression of lysosome-associated membrane protein 1 (LAMP-1) and increased the ratio of light chain 3 (LC3), LC3BII/LC3BI. The expression of TH also decreased. Furthermore, α-synuclein (α-SYN) and parkin were evaluated by immunofluorescence (IF) at 1.0 and 2.5 mM MPP+ after 24 h. A qualitative analysis revealed decreased parkin expression while α-SYN aggregation was observed in the cytoplasm and the nucleus. These data suggest that in HDNPCs MPP+ can cause cytotoxicity and neuronal damage. This damage may be mediated by autophagy, dopamine synthesis, and protein aggregation. The combination of HDNPCs and MPP+ may serve as valuable in vitro model of progressive dopaminergic neurotoxicity for research into potential treatments for PD.http://www.sciencedirect.com/science/article/pii/S2214750022000750MPP+Parkinson's diseaseIn vitro modelAutophagyProtein aggregation |
| spellingShingle | Elvis Cuevas Aida Guzman Susan M. Burks Alejandro Ramirez-Lee Syed F. Ali Syed Z. Imam Autophagy and protein aggregation as a mechanism of dopaminergic degeneration in a primary human dopaminergic neuronal model Toxicology Reports MPP+ Parkinson's disease In vitro model Autophagy Protein aggregation |
| title | Autophagy and protein aggregation as a mechanism of dopaminergic degeneration in a primary human dopaminergic neuronal model |
| title_full | Autophagy and protein aggregation as a mechanism of dopaminergic degeneration in a primary human dopaminergic neuronal model |
| title_fullStr | Autophagy and protein aggregation as a mechanism of dopaminergic degeneration in a primary human dopaminergic neuronal model |
| title_full_unstemmed | Autophagy and protein aggregation as a mechanism of dopaminergic degeneration in a primary human dopaminergic neuronal model |
| title_short | Autophagy and protein aggregation as a mechanism of dopaminergic degeneration in a primary human dopaminergic neuronal model |
| title_sort | autophagy and protein aggregation as a mechanism of dopaminergic degeneration in a primary human dopaminergic neuronal model |
| topic | MPP+ Parkinson's disease In vitro model Autophagy Protein aggregation |
| url | http://www.sciencedirect.com/science/article/pii/S2214750022000750 |
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