1
|
Lelos MJ. Investigating cell therapies in animal models of Parkinson's and Huntington's disease: Current challenges and considerations. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 166:159-189. [PMID: 36424091 DOI: 10.1016/bs.irn.2022.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cell therapeutics have entered into an exciting era, with first-in-person clinical trials underway for Parkinson's disease and novel cell therapies in development for other neurodegenerative diseases. In the hope of ensuring successful translation of these novel cell products to the clinic, a significant amount of preclinical work continues to be undertaken. Rodent models of neural transplantation are required to thoroughly assess the survival, safety and efficacy of novel therapeutics. It is critical to produce robust and reliable preclinical data, in order to increase the likelihood of clinical success. As a result, significant effort has been driven into generating ever more relevant model systems, from genetically modified disease models to mice with humanized immune systems. Despite this, several challenges remain in the quest to assess human cells in the rodent brain long-term. Here, with a focus on models of Parkinson's and Huntington's disease, we discuss key considerations for choosing an appropriate rodent model for neural transplantation. We also consider the challenges associated with long-term survival and assessment of functional efficacy in these models, as well as the need to consider the clinical relevance of the model. While the choice of model will be dependent on the scientific question, by considering the caveats associated with each model, we identify opportunities to optimize the preclinical assessment and generate reliable data on our novel cell therapeutics.
Collapse
Affiliation(s)
- Mariah J Lelos
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, United Kingdom.
| |
Collapse
|
2
|
Lane EL, Lelos MJ. Defining the unknowns for cell therapies in Parkinson's disease. Dis Model Mech 2022; 15:276886. [PMID: 36165848 PMCID: PMC9555765 DOI: 10.1242/dmm.049543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
First-in-human clinical trials have commenced to test the safety and efficacy of cell therapies for people with Parkinson's disease (PD). Proof of concept that this neural repair strategy is efficacious is based on decades of preclinical studies and clinical trials using primary foetal cells, as well as a significant literature exploring more novel stem cell-derived products. Although several measures of efficacy have been explored, including the successful in vitro differentiation of stem cells to dopamine neurons and consistent alleviation of motor dysfunction in rodent models, many unknowns still remain regarding the long-term clinical implications of this treatment strategy. Here, we consider some of these outstanding questions, including our understanding of the interaction between anti-Parkinsonian medication and the neural transplant, the impact of the cell therapy on cognitive or neuropsychiatric symptoms of PD, the role of neuroinflammation in the therapeutic process and the development of graft-induced dyskinesias. We identify questions that are currently pertinent to the field that require further exploration, and pave the way for a more holistic understanding of this neural repair strategy for treatment of PD.
Collapse
Affiliation(s)
- Emma L Lane
- Cardiff School of Pharmacy and Pharmaceutical Sciences, King Edward VII Avenue, Cardiff University, Cardiff CF10 3NB, UK
| | - Mariah J Lelos
- School of Biosciences, Museum Avenue, Cardiff University, Cardiff CF10 3AX, UK
| |
Collapse
|
3
|
Elabi OF, Pass R, Sormonta I, Nolbrant S, Drummond N, Kirkeby A, Kunath T, Parmar M, Lane EL. Human Embryonic Stem Cell-Derived Dopaminergic Grafts Alleviate L-DOPA Induced Dyskinesia. JOURNAL OF PARKINSON'S DISEASE 2022; 12:1881-1896. [PMID: 35466951 DOI: 10.3233/jpd-212920] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
BACKGROUND First-in-human studies to test the efficacy and safety of human embryonic stem cells (hESC)-derived dopaminergic cells in the treatment of Parkinson's disease (PD) are imminent. Pre-clinical studies using hESC-derived dopamine neuron transplants in rat models have indicated that the benefits parallel those shown with fetal tissue but have thus far failed to consider how ongoing L-DOPA administration might impact on the graft. OBJECTIVE To determine whether L-DOPA impacts on survival and functional recovery following grafting of hESC-derived dopaminergic neurons. METHODS Unilateral 6-OHDA lesioned rats were administered with either saline or L-DOPA prior to, and for 18 weeks following surgical implantation of dopaminergic neural progenitors derived from RC17 hESCs according to two distinct protocols in independent laboratories. RESULTS Grafts from both protocols elicited reduction in amphetamine-induced rotations. Reduced L-DOPA-induced dyskinesia preceded the improvement in amphetamine-induced rotations. Furthermore, L-DOPA had no effect on overall survival (HuNu) or dopaminergic neuron content of the graft (TH positive cells) but did lead to an increase in the number of GIRK2 positive neurons. CONCLUSION Critically, we found that L-DOPA was not detrimental to graft function, potentially enhancing graft maturation and promoting an A9 phenotype. Early improvement of L-DOPA-induced dyskinesia suggests that grafts may support the handling of exogenously supplied dopamine earlier than improvements in amphetamine-induced behaviours indicate. Given that one of the protocols will be employed in the production of cells for the European STEM-PD clinical trial, this is vital information for the management of patients and achieving optimal outcomes following transplantation of hESC-derived grafts for PD.
Collapse
Affiliation(s)
- Osama F Elabi
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| | - Rachel Pass
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| | - Irene Sormonta
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| | - Sara Nolbrant
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Nicola Drummond
- Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Agnete Kirkeby
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Lund University, Lund, Sweden
- Department of Neuroscience and The Novo Nordisk Foundation Center for Stem Cell Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Tilo Kunath
- Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Malin Parmar
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Emma L Lane
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| |
Collapse
|
4
|
Elabi OF, Davies JS, Lane EL. L-dopa-Dependent Effects of GLP-1R Agonists on the Survival of Dopaminergic Cells Transplanted into a Rat Model of Parkinson Disease. Int J Mol Sci 2021; 22:ijms222212346. [PMID: 34830228 PMCID: PMC8618072 DOI: 10.3390/ijms222212346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/05/2021] [Accepted: 11/12/2021] [Indexed: 12/27/2022] Open
Abstract
Cell therapy is a promising treatment for Parkinson's disease (PD), however clinical trials to date have shown relatively low survival and significant patient-to-patient variability. Glucagon Like Peptide-1 receptor (GLP-1R) agonists have potential neuroprotective effects on endogenous dopaminergic neurons. This study explores whether these agents could similarly support the growth and survival of newly transplanted neurons. 6-OHDA lesioned Sprague Dawley rats received intra-striatal grafts of dopaminergic ventral mesencephalic cells from embryonic day 14 Wistar rat embryos. Transplanted rats then received either saline or L-dopa (12 mg/kg) administered every 48 h prior to, and following cell transplantation. Peripheral GLP-1R agonist administration (exendin-4, 0.5 μg/kg twice daily or liraglutide, 100 μg/kg once daily) commenced immediately after cell transplantation and was maintained throughout the study. Graft survival increased under administration of exendin-4, with motor function improving significantly following treatment with both exendin-4 and liraglutide. However, this effect was not observed in rats administered with L-dopa. In contrast, L-dopa treatment with liraglutide increased graft volume, with parallel increases in motor function. However, this improvement was accompanied by an increase in leukocyte infiltration around the graft. The co-administration of L-dopa and exendin-4 also led to indicators of insulin resistance not seen with liraglutide, which may underpin the differential effects observed between the two GLP1-R agonists. Overall, there may be some benefit to the supplementation of grafted patients with GLP-1R agonists but the potential interaction with other pharmacological treatments needs to be considered in more depth.
Collapse
Affiliation(s)
- Osama F. Elabi
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK
- Correspondence: (O.F.E.); (E.L.L.)
| | - Jeffrey S. Davies
- Institute of Life Sciences, School of Medicine, Swansea University, Swansea SA2 8PP, UK;
| | - Emma L. Lane
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK
- Correspondence: (O.F.E.); (E.L.L.)
| |
Collapse
|
5
|
Hutny M, Hofman J, Klimkowicz-Mrowiec A, Gorzkowska A. Current Knowledge on the Background, Pathophysiology and Treatment of Levodopa-Induced Dyskinesia-Literature Review. J Clin Med 2021; 10:jcm10194377. [PMID: 34640395 PMCID: PMC8509231 DOI: 10.3390/jcm10194377] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/02/2021] [Accepted: 09/22/2021] [Indexed: 02/07/2023] Open
Abstract
Levodopa remains the primary drug for controlling motor symptoms in Parkinson’s disease through the whole course, but over time, complications develop in the form of dyskinesias, which gradually become more frequent and severe. These abnormal, involuntary, hyperkinetic movements are mainly characteristic of the ON phase and are triggered by excess exogenous levodopa. They may also occur during the OFF phase, or in both phases. Over the past 10 years, the issue of levodopa-induced dyskinesia has been the subject of research into both the substrate of this pathology and potential remedial strategies. The purpose of the present study was to review the results of recent research on the background and treatment of dyskinesia. To this end, databases were reviewed using a search strategy that included both relevant keywords related to the topic and appropriate filters to limit results to English language literature published since 2010. Based on the selected papers, the current state of knowledge on the morphological, functional, genetic and clinical features of levodopa-induced dyskinesia, as well as pharmacological, genetic treatment and other therapies such as deep brain stimulation, are described.
Collapse
Affiliation(s)
- Michał Hutny
- Students’ Scientific Society, Department of Neurorehabilitation, Faculty of Medical Sciences in Katowice, Medical University of Silesia, 40-752 Katowice, Poland;
- Correspondence:
| | - Jagoda Hofman
- Students’ Scientific Society, Department of Neurorehabilitation, Faculty of Medical Sciences in Katowice, Medical University of Silesia, 40-752 Katowice, Poland;
| | - Aleksandra Klimkowicz-Mrowiec
- Department of Internal Medicine and Gerontology, Faculty of Medicine, Medical College, Jagiellonian University, 30-688 Kraków, Poland;
| | - Agnieszka Gorzkowska
- Department of Neurorehabilitation, Faculty of Medical Sciences, School of Medicine, Medical University of Silesia, 40-752 Katowice, Poland;
| |
Collapse
|
6
|
The immunogenicity of midbrain dopaminergic neurons and the implications for neural grafting trials in Parkinson's disease. Neuronal Signal 2021; 5:NS20200083. [PMID: 34552761 PMCID: PMC8438115 DOI: 10.1042/ns20200083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/10/2021] [Accepted: 08/16/2021] [Indexed: 11/17/2022] Open
Abstract
Dopaminergic (DA) cell replacement therapies are a promising experimental treatment for Parkinson’s disease (PD) and a number of different types of DA cell-based therapies have already been trialled in patients. To date, the most successful have been allotransplants of foetal ventral midbrain but even then, the results have been inconsistent. This coupled to the ethical and logistical problems with using this tissue has meant that an alternative cell source has been sought of which human pluripotent stem cells (hPSCs) sources have proven very attractive. Robust protocols for making mesencephalic DA (mesDA) progenitor cells from hPSCs now exist and the first in-human clinical trials have or are about to start. However, while their safety and efficacy are well understood, relatively little is known about their immunogenicity and in this review, we briefly summarise this with reference mainly to the limited literature on human foetal DA cells.
Collapse
|
7
|
Percie du Sert N, Ahluwalia A, Alam S, Avey MT, Baker M, Browne WJ, Clark A, Cuthill IC, Dirnagl U, Emerson M, Garner P, Holgate ST, Howells DW, Hurst V, Karp NA, Lazic SE, Lidster K, MacCallum CJ, Macleod M, Pearl EJ, Petersen OH, Rawle F, Reynolds P, Rooney K, Sena ES, Silberberg SD, Steckler T, Würbel H. Reporting animal research: Explanation and elaboration for the ARRIVE guidelines 2.0. PLoS Biol 2020; 18:e3000411. [PMID: 32663221 PMCID: PMC7360025 DOI: 10.1371/journal.pbio.3000411] [Citation(s) in RCA: 989] [Impact Index Per Article: 247.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Improving the reproducibility of biomedical research is a major challenge. Transparent and accurate reporting is vital to this process; it allows readers to assess the reliability of the findings and repeat or build upon the work of other researchers. The ARRIVE guidelines (Animal Research: Reporting In Vivo Experiments) were developed in 2010 to help authors and journals identify the minimum information necessary to report in publications describing in vivo experiments. Despite widespread endorsement by the scientific community, the impact of ARRIVE on the transparency of reporting in animal research publications has been limited. We have revised the ARRIVE guidelines to update them and facilitate their use in practice. The revised guidelines are published alongside this paper. This explanation and elaboration document was developed as part of the revision. It provides further information about each of the 21 items in ARRIVE 2.0, including the rationale and supporting evidence for their inclusion in the guidelines, elaboration of details to report, and examples of good reporting from the published literature. This document also covers advice and best practice in the design and conduct of animal studies to support researchers in improving standards from the start of the experimental design process through to publication.
Collapse
Affiliation(s)
| | - Amrita Ahluwalia
- The William Harvey Research Institute, London, United Kingdom
- Barts Cardiovascular CTU, Queen Mary University of London, London, United Kingdom
| | - Sabina Alam
- Taylor & Francis Group, London, United Kingdom
| | - Marc T. Avey
- Health Science Practice, ICF, Durham, North Carolina, United States of America
| | - Monya Baker
- Nature, San Francisco, California, United States of America
| | | | | | - Innes C. Cuthill
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Ulrich Dirnagl
- QUEST Center for Transforming Biomedical Research, Berlin Institute of Health & Department of Experimental Neurology, Charite Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Emerson
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Paul Garner
- Centre for Evidence Synthesis in Global Health, Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Stephen T. Holgate
- Clinical and Experimental Sciences, University of Southampton, Southampton, United Kingdom
| | - David W. Howells
- Tasmanian School of Medicine, University of Tasmania, Hobart, Australia
| | | | - Natasha A. Karp
- Data Sciences & Quantitative Biology, Discovery Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | | | | | | | - Malcolm Macleod
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Ole H. Petersen
- Academia Europaea Knowledge Hub, Cardiff University, Cardiff, United Kingdom
| | | | - Penny Reynolds
- Statistics in Anesthesiology Research (STAR) Core, Department of Anesthesiology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Kieron Rooney
- Discipline of Exercise and Sport Science, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Emily S. Sena
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Shai D. Silberberg
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States of America
| | | | - Hanno Würbel
- Veterinary Public Health Institute, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| |
Collapse
|
8
|
Cell therapy for Parkinson′s disease is coming of age: current challenges and future prospects with a focus on immunomodulation. Gene Ther 2019; 27:6-14. [DOI: 10.1038/s41434-019-0077-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 03/12/2019] [Accepted: 03/20/2019] [Indexed: 12/17/2022]
|
9
|
Cambeiro-Pérez N, Hidalgo-Cantabrana C, Moro-García MA, Alonso-Arias R, Simal-Gándara J, Sánchez B, Martínez-Carballo E. A Metabolomics Approach Reveals Immunomodulatory Effects of Proteinaceous Molecules Derived From Gut Bacteria Over Human Peripheral Blood Mononuclear Cells. Front Microbiol 2018; 9:2701. [PMID: 30524384 PMCID: PMC6262353 DOI: 10.3389/fmicb.2018.02701] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 10/23/2018] [Indexed: 01/24/2023] Open
Abstract
There are strong evidences that probiotics influence the immune status of the host, in a strain-specific manner, acting in the gastrointestinal tract. On the hypothesis that certain extracellular proteins and peptides from gut bacteria may mediate part of this immunomodulation and assuming they are able to diffuse through the mucus layer and interact with immune cells we have developed this work. Our study attempts to understand the immunomodulatory mechanisms of (i) Pext, the extracellular protein fraction of Lactobacillus acidophilus DSM20079T, (ii) HM14, a peptide encrypted in an extracellular glycoside hydrolase from Bifidobacterium longum NCIMB 8809 and (iii) Escherichia coli O111:B4 lipopolysaccharide (LPS), a well-known pro-inflammatory molecule, over human peripheral blood mononuclear cells (PBMCs). An untargeted LC-ESI-QTOF-MS metabolomics approach was applied to reveal intracellular changes in treated-PBMCs isolated from healthy donors. Differences in NADH arrest, NAD+ concentration reduction, as well as increases in palmitic acid and methanephrin were observed in HM14 and Pext treated-cells compared to those stimulated with LPS. This would support an anti-inflammatory molecular mechanism of action of such proteinaceous molecules. Moreover, this methodology has confirms the importance of metabolomics approaches to better understanding immune cell responses to gut bacterial-derived molecules.
Collapse
Affiliation(s)
- Noelia Cambeiro-Pérez
- Nutrition and Bromatology Group, Department of Analytical and Food Chemistry, Faculty of Food Science, University of Vigo, Ourense, Spain
| | - Claudio Hidalgo-Cantabrana
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas, Villaviciosa, Spain.,Department of Immunology, Hospital Universitario Central de Asturias, Oviedo, Spain
| | - Marco A Moro-García
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas, Villaviciosa, Spain.,Department of Immunology, Hospital Universitario Central de Asturias, Oviedo, Spain
| | - Rebeca Alonso-Arias
- Department of Immunology, Hospital Universitario Central de Asturias, Oviedo, Spain
| | - Jesús Simal-Gándara
- Nutrition and Bromatology Group, Department of Analytical and Food Chemistry, Faculty of Food Science, University of Vigo, Ourense, Spain
| | - Borja Sánchez
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas, Villaviciosa, Spain
| | - Elena Martínez-Carballo
- Nutrition and Bromatology Group, Department of Analytical and Food Chemistry, Faculty of Food Science, University of Vigo, Ourense, Spain
| |
Collapse
|
10
|
Lane EL. L-DOPA for Parkinson's disease-a bittersweet pill. Eur J Neurosci 2018; 49:384-398. [PMID: 30118169 DOI: 10.1111/ejn.14119] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/23/2018] [Accepted: 07/30/2018] [Indexed: 01/02/2023]
Abstract
3,4-dihydroxy-L-phenylalanine (L-DOPA) is the gold standard treatment for Parkinson's disease. It has earned that title through its highly effective treatment of some of the motor symptoms in the early stages of the disease but it is a far from perfect drug. The inevitable long-term treatment that comes with this chronic neurodegenerative condition raises the risk significantly of the development of motor fluctuations including disabling L-DOPA-induced dyskinesia. Being unsurpassed as a therapy means that understanding the mechanisms of dyskinesia priming and induction is vital to the search for therapies to treat these side effects and allow optimal use of L-DOPA. However, L-DOPA use may also have consequences (positive or negative) for the development of other interventions, such as cell transplantation, which are designed to treat or repair the ailing brain. This review looks at the issues around the use of L-DOPA with a focus on its potential impact on advanced reparative interventions.
Collapse
Affiliation(s)
- Emma L Lane
- Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| |
Collapse
|
11
|
Mackie P, Lebowitz J, Saadatpour L, Nickoloff E, Gaskill P, Khoshbouei H. The dopamine transporter: An unrecognized nexus for dysfunctional peripheral immunity and signaling in Parkinson's Disease. Brain Behav Immun 2018; 70:21-35. [PMID: 29551693 PMCID: PMC5953824 DOI: 10.1016/j.bbi.2018.03.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 02/06/2023] Open
Abstract
The second-most common neurodegenerative disease, Parkinson's Disease (PD) has three hallmarks: dysfunctional dopamine transmission due, at least in part, to dopamine neuron degeneration; intracellular inclusions of α-synuclein aggregates; and neuroinflammation. The origin and interplay of these features remains a puzzle, as does the underlying mechanism of PD pathogenesis and progression. When viewed in the context of neuroimmunology, dopamine also plays a role in regulating peripheral immune cells. Intriguingly, plasma dopamine levels are altered in PD, suggesting collateral dysregulation of peripheral dopamine transmission. The dopamine transporter (DAT), the main regulator of dopaminergic tone in the CNS, is known to exist in lymphocytes and monocytes/macrophages, but little is known about peripheral DAT biology or how DAT regulates the dopaminergic tone, much less how peripheral DAT alters immune function. Our review is guided by the hypothesis that dysfunctional peripheral dopamine signaling might be linked to the dysfunctional immune responses in PD and thereby suggests a potential bidirectional communication between central and peripheral dopamine systems. This review seeks to foster new perspectives concerning PD pathogenesis and progression.
Collapse
Affiliation(s)
- Phillip Mackie
- University of Florida College of Medicine, Department of Neuroscience, Gainesville, FL 32611, United States
| | - Joe Lebowitz
- University of Florida College of Medicine, Department of Neuroscience, Gainesville, FL 32611, United States
| | - Leila Saadatpour
- University of Florida College of Medicine, Department of Neuroscience, Gainesville, FL 32611, United States
| | - Emily Nickoloff
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, United States
| | - Peter Gaskill
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, United States
| | - Habibeh Khoshbouei
- University of Florida College of Medicine, Department of Neuroscience, Gainesville, FL 32611, United States.
| |
Collapse
|