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Mackie PM, Koshy J, Bhogade M, Hammoor T, Hachmeister W, Lloyd GM, Paterno G, Bolen M, Tansey MG, Giasson BI, Khoshbouei H. Complement C1q-dependent engulfment of alpha-synuclein induces ENS-resident macrophage exhaustion and accelerates Parkinson's-like gut pathology. bioRxiv 2023:2023.10.24.563832. [PMID: 37961460 PMCID: PMC10634831 DOI: 10.1101/2023.10.24.563832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Deposition of misfolded α-synuclein (αsyn) in the enteric nervous system (ENS) is found in multiple neurodegenerative diseases. It is hypothesized that ENS synucleinopathy contributes to both the pathogenesis and non-motor morbidity in Parkinson's Disease (PD), but the cellular and molecular mechanisms that shape enteric histopathology and dysfunction are poorly understood. Here, we demonstrate that ENS-resident macrophages, which play a critical role in maintaining ENS homeostasis, initially respond to enteric neuronal αsyn pathology by upregulating machinery for complement-mediated engulfment. Pharmacologic depletion of ENS-macrophages or genetic deletion of C1q enhanced enteric neuropathology. Conversely, C1q deletion ameliorated gut dysfunction, indicating that complement partially mediates αsyn-induced gut dysfunction. Internalization of αsyn led to increased endo-lysosomal stress that resulted in macrophage exhaustion and temporally correlated with the progression of ENS pathology. These novel findings highlight the importance of enteric neuron-macrophage interactions in removing toxic protein aggregates that putatively shape the earliest stages of PD in the periphery.
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Affiliation(s)
- P M Mackie
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
| | - J Koshy
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
| | - M Bhogade
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
| | - T Hammoor
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
| | - W Hachmeister
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
| | - G M Lloyd
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
- Center for Translational Research in Neurodegenerative Disease, University of Florida College of Medicine. Gainesville, FL, 32610
| | - G Paterno
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
- Center for Translational Research in Neurodegenerative Disease, University of Florida College of Medicine. Gainesville, FL, 32610
| | - M Bolen
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
- Center for Translational Research in Neurodegenerative Disease, University of Florida College of Medicine. Gainesville, FL, 32610
| | - M G Tansey
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
- Center for Translational Research in Neurodegenerative Disease, University of Florida College of Medicine. Gainesville, FL, 32610
- Department of Neurology and Fixel Institute for Neurological Diseases, University of Florida Health, Gainesville, Florida, 32610
| | - B I Giasson
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
- Center for Translational Research in Neurodegenerative Disease, University of Florida College of Medicine. Gainesville, FL, 32610
| | - H Khoshbouei
- Department of Neuroscience, University of Florida College of Medicine. Gainesville, FL, 32610
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Gopinath A, Mackie PM, Phan LT, Mirabel R, Smith AR, Miller E, Franks S, Syed O, Riaz T, Law BK, Urs N, Khoshbouei H. Who Knew? Dopamine Transporter Activity Is Critical in Innate and Adaptive Immune Responses. Cells 2023; 12:cells12020269. [PMID: 36672204 PMCID: PMC9857305 DOI: 10.3390/cells12020269] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/22/2022] [Accepted: 01/04/2023] [Indexed: 01/12/2023] Open
Abstract
The dopamine transporter (DAT) regulates the dimension and duration of dopamine transmission. DAT expression, its trafficking, protein-protein interactions, and its activity are conventionally studied in the CNS and within the context of neurological diseases such as Parkinson's Diseases and neuropsychiatric diseases such as drug addiction, attention deficit hyperactivity and autism. However, DAT is also expressed at the plasma membrane of peripheral immune cells such as monocytes, macrophages, T-cells, and B-cells. DAT activity via an autocrine/paracrine signaling loop regulates macrophage responses to immune stimulation. In a recent study, we identified an immunosuppressive function for DAT, where blockade of DAT activity enhanced LPS-mediated production of IL-6, TNF-α, and mitochondrial superoxide levels, demonstrating that DAT activity regulates macrophage immune responses. In the current study, we tested the hypothesis that in the DAT knockout mice, innate and adaptive immunity are perturbed. We found that genetic deletion of DAT (DAT-/-) results in an exaggerated baseline inflammatory phenotype in peripheral circulating myeloid cells. In peritoneal macrophages obtained from DAT-/- mice, we identified increased MHC-II expression and exaggerated phagocytic response to LPS-induced immune stimulation, suppressed T-cell populations at baseline and following systemic endotoxemia and exaggerated memory B cell expansion. In DAT-/- mice, norepinephrine and dopamine levels are increased in spleen and thymus, but not in circulating serum. These findings in conjunction with spleen hypoplasia, increased splenic myeloid cells, and elevated MHC-II expression, in DAT-/- mice further support a critical role for DAT activity in peripheral immunity. While the current study is only focused on identifying the role of DAT in peripheral immunity, our data point to a much broader implication of DAT activity than previously thought. This study is dedicated to the memory of Dr. Marc Caron who has left an indelible mark in the dopamine transporter field.
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Affiliation(s)
- Adithya Gopinath
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
- Correspondence: (A.G.); (H.K.)
| | - Phillip M. Mackie
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Leah T. Phan
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Rosa Mirabel
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32611, USA
| | - Aidan R. Smith
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Emily Miller
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Stephen Franks
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Ohee Syed
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Tabish Riaz
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Brian K. Law
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32611, USA
| | - Nikhil Urs
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32611, USA
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
- Correspondence: (A.G.); (H.K.)
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Mackie PM, Gopinath A, Montas DM, Nielsen A, Smith A, Nolan RA, Runner K, Matt SM, McNamee J, Riklan JE, Adachi K, Doty A, Ramirez-Zamora A, Yan L, Gaskill PJ, Streit WJ, Okun MS, Khoshbouei H. Functional characterization of the biogenic amine transporters on human macrophages. JCI Insight 2022; 7:151892. [PMID: 35015729 PMCID: PMC8876465 DOI: 10.1172/jci.insight.151892] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 01/05/2022] [Indexed: 11/17/2022] Open
Abstract
Monocyte-derived macrophages are key players in tissue homeostasis and diseases regulated by a variety of signaling molecules. Recent literature has highlighted the ability for biogenic amines to regulate macrophage functions, but the mechanisms governing biogenic amine signaling in and around immune cells remains nebulous. In the central nervous system (CNS), biogenic amine transporters are regarded as the master regulators of neurotransmitter signaling. While we and others have shown that macrophages express these transporters, relatively little is known of their function in these cells. To address these knowledge gaps, we investigated the function of norepinephrine (NET) and dopamine (DAT) transporters on human monocyte-derived macrophages. We found that both NET and DAT are present and can uptake substrate from the extracellular space at baseline. Not only was DAT expressed in cultured monocyte-derived macrophages (MDMs), but it was also detected in a subset of intestinal macrophages in situ. Surprisingly, we discovered a NET-independent, DAT-mediated immuno-modulatory mechanism in response to lipopolysaccharide (LPS). LPS induced reverse transport of dopamine through DAT, engaging an autocrine/paracrine signaling loop that regulated the macrophage response. Removing this signaling loop enhanced the pro-inflammatory response to LPS. Collectively, our data introduce a potential role for DAT in the regulation of innate immunity.
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Affiliation(s)
- Phillip M Mackie
- Department of Neuroscience, University of Florida, Gainesville, United States of America
| | - Adithya Gopinath
- Department of Neuroscience, McKnight Brain Insitute, University of Florida College of Medicine, Gainesville, United States of America
| | - Dominic M Montas
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Alyssa Nielsen
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Aidan Smith
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Rachel A Nolan
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, United States of America
| | - Kaitlyn Runner
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, United States of America
| | - Stephanie M Matt
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, United States of America
| | - John McNamee
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Joshua E Riklan
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Kengo Adachi
- Neuronal Signal Transduction Group, Max Plank Florida Institute for Neuroscience, Jupiter, United States of America
| | - Andria Doty
- Flow Cytometry Core Facility, University of Florida College of Medicine, Gainesville, United States of America
| | - Adolfo Ramirez-Zamora
- Department of Neurology, University of Florida College of Medicine, Gainesville, United States of America
| | - Long Yan
- Neuronal Signal Transduction Group, Max Plank Florida Institute for Neuroscience, Jupiter, United States of America
| | - Peter J Gaskill
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, United States of America
| | - Wolfgang J Streit
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
| | - Michael S Okun
- University of Florida College of Medicine, Gainesville, United States of America
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, United States of America
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Lin M, Mackie PM, Shaerzadeh F, Gamble-George J, Miller DR, Martyniuk CJ, Khoshbouei H. In Parkinson's patient-derived dopamine neurons, the triplication of α-synuclein locus induces distinctive firing pattern by impeding D2 receptor autoinhibition. Acta Neuropathol Commun 2021; 9:107. [PMID: 34099060 PMCID: PMC8185945 DOI: 10.1186/s40478-021-01203-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 05/17/2021] [Indexed: 12/12/2022] Open
Abstract
Pathophysiological changes in dopamine neurons precede their demise and contribute to the early phases of Parkinson's disease (PD). Intracellular pathological inclusions of the protein α-synuclein within dopaminergic neurons are a cardinal feature of PD, but the mechanisms by which α-synuclein contributes to dopaminergic neuron vulnerability remain unknown. The inaccessibility to diseased tissue has been a limitation in studying progression of pathophysiology prior to degeneration of dopamine neurons. To address these issues, we differentiated induced pluripotent stem cells (iPSCs) from a PD patient carrying the α-synuclein triplication mutation (AST) and an unaffected first-degree relative (NAS) into dopaminergic neurons. In human-like dopamine neurons α-synuclein overexpression reduced the functional availability of D2 receptors, resulting in a stark dysregulation in firing activity, dopamine release, and neuronal morphology. We back-translated these findings into primary mouse neurons overexpressing α-synuclein and found a similar phenotype, supporting the causal role for α-synuclein. Importantly, application of D2 receptor agonist, quinpirole, restored the altered firing activity of AST-derived dopaminergic neurons to normal levels. These results provide novel insights into the pre-degenerative pathophysiological neuro-phenotype induced by α-synuclein overexpression and introduce a potential mechanism for the long-established clinical efficacy of D2 receptor agonists in the treatment of PD.
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Affiliation(s)
- Min Lin
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA
| | - Phillip M Mackie
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA
| | - Fatima Shaerzadeh
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA
| | | | - Douglas R Miller
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA
| | - Chris J Martyniuk
- Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA.
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5
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Abstract
Proper normalization of RT-qPCR data is pivotal to the interpretation of results and accuracy of scientific conclusions. Though different approaches may be taken, normalization against multiple reference genes is now standard practice. Genes traditionally used and deemed constitutively expressed have demonstrated variability in expression under different experimental conditions, necessitating the proper validation of reference genes prior to utilization. Considering the wide use of fibroblasts in research and scientific applications, it is imperative that suitable reference genes for fibroblasts of different animal origins and conditions be elucidated. Previous studies on bovine fibroblasts have tested limited genes and/or samples. Herein, we present an extensive study investigating the expression stability of 16 candidate reference genes across 7 untreated bovine fibroblast cell lines subjected to controlled conditions. Data were analysed using various statistical tools and algorithms, including geNorm, NormFinder, BestKeeper, and RefFinder. A combined use of GUSB and RPL13A was determined to be the best approach for data normalization in untreated bovine fibroblasts.
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Affiliation(s)
- T Toorani
- Reproductive Sciences, Toronto Zoo, Scarborough, ON, M1B 5K7, Canada
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - P M Mackie
- Reproductive Sciences, Toronto Zoo, Scarborough, ON, M1B 5K7, Canada
| | - G F Mastromonaco
- Reproductive Sciences, Toronto Zoo, Scarborough, ON, M1B 5K7, Canada.
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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Gopinath A, Doty A, Mackie PM, Hashimi B, Francis M, Saadatpour L, Saha K, Shaw G, Ramirez-Zamora A, Okun MS, Streit WJ, Khoshbouei H. A novel approach to study markers of dopamine signaling in peripheral immune cells. J Immunol Methods 2019; 476:112686. [PMID: 31634479 DOI: 10.1016/j.jim.2019.112686] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 01/01/2023]
Abstract
Human monocytes express known markers of dopamine synthesis, storage and clearance, including dopamine transporter (DAT), tyrosine hydroxylase (TH), all subtypes of dopamine receptors and vesicular monoamine transporter 2 (VMAT2). Immunohistochemical and immunofluorescent methodologies have traditionally been employed to determine DAT and TH expression in the CNS, their detection in the blood and specifically in the peripheral monocytes has not been studied by flow cytometry. Flow cytometry assays are widely used in medicine and in basic, preclinical or clinical research to quantify physical and chemical characteristics of target cell populations. Here, we have established a highly sensitive and reproducible flow cytometry panel to detect and quantify DAT and TH expression in freshly isolated or cryopreserved human peripheral monocytes. In healthy humans (n = 41 biological replicates), we show baseline DAT and TH expressing monocytes constitute ~12% of the peripheral blood mononuclear cell (PBMC) fraction when examined in fresh isolation from whole blood. Using an identical flow cytometry panel, we found that cryopreservation of PBMCs using multiple techniques resulted in altered PBMC populations as compared to fresh isolation and relative to one another. Among these, we identified an optimum cryopreservation method for detecting TH and DAT in cryopreserved PBMCs. Our data provide a sensitive and reproducible approach to examine dopamine signaling in peripheral human immune cells. This approach can be applied to study peripheral dopamine signaling under healthy and potentially under disease conditions. The use of dopamine signaling could also be explored as a technique to monitor therapeutic interventions particularly those targeting DAT and TH in the periphery.
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Affiliation(s)
- Adithya Gopinath
- Department of Neuroscience, University of Florida College of Medicine, United States of America
| | - Andria Doty
- ICBR Flow Cytometry, University of Florida, United States of America
| | - Phillip M Mackie
- Department of Neuroscience, University of Florida College of Medicine, United States of America
| | - Basil Hashimi
- Department of Neuroscience, University of Florida College of Medicine, United States of America
| | - Madison Francis
- Department of Neuroscience, University of Florida College of Medicine, United States of America
| | - Leila Saadatpour
- Department of Neuroscience, University of Florida College of Medicine, United States of America
| | - Kaustuv Saha
- Department of Neuroscience, University of Florida College of Medicine, United States of America
| | - Gerry Shaw
- Department of Neuroscience, University of Florida College of Medicine, United States of America
| | - Adolfo Ramirez-Zamora
- Department of Neurology, Fixel Institute for Neurological Diseases, Center for Movement Disorders and Neurorestoration, University of Florida College of Medicine, United States of America
| | - Michael S Okun
- Department of Neurology, Fixel Institute for Neurological Diseases, Center for Movement Disorders and Neurorestoration, University of Florida College of Medicine, United States of America
| | - Wolfgang J Streit
- Department of Neuroscience, University of Florida College of Medicine, United States of America
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida College of Medicine, United States of America.
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Lebowitz JJ, Pino JA, Mackie PM, Lin M, Hurst C, Divita K, Collins AT, Koutzoumis DN, Torres GE, Khoshbouei H. Clustered Kv2.1 decreases dopamine transporter activity and internalization. J Biol Chem 2019; 294:6957-6971. [PMID: 30824538 DOI: 10.1074/jbc.ra119.007441] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/26/2019] [Indexed: 01/16/2023] Open
Abstract
The dopamine transporter (DAT) regulates dopamine neurotransmission via reuptake of dopamine released into the extracellular space. Interactions with partner proteins alter DAT function and thereby dynamically shape dopaminergic tone important for normal brain function. However, the extent and nature of these interactions are incompletely understood. Here, we describe a novel physical and functional interaction between DAT and the voltage-gated K+ channel Kv2.1 (potassium voltage-gated channel subfamily B member 1 or KCNB1). To examine the functional consequences of this interaction, we employed a combination of immunohistochemistry, immunofluorescence live-cell microscopy, co-immunoprecipitation, and electrophysiological approaches. Consistent with previous reports, we found Kv2.1 is trafficked to membrane-bound clusters observed both in vivo and in vitro in rodent dopamine neurons. Our data provide evidence that clustered Kv2.1 channels decrease DAT's lateral mobility and inhibit its internalization, while also decreasing canonical transporter activity by altering DAT's conformational equilibrium. These results suggest that Kv2.1 clusters exert a spatially discrete homeostatic braking mechanism on DAT by inducing a relative increase in inward-facing transporters. Given recent reports of Kv2.1 dysregulation in neurological disorders, it is possible that alterations in the functional interaction between DAT and Kv2.1 affect dopamine neuron activity.
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Affiliation(s)
- Joseph J Lebowitz
- From the Departments of Neuroscience and.,T32 in Movement Disorders and Neurorestoration, Fixel Center for Neurological Diseases, UF Health, Gainesville, Florida 32610
| | - Jose A Pino
- Pharmacology and Experimental Therapeutics, College of Medicine, University of Florida, Gainesville, Florida 32610 and
| | | | - Min Lin
- From the Departments of Neuroscience and
| | | | | | | | - Dimitri N Koutzoumis
- Pharmacology and Experimental Therapeutics, College of Medicine, University of Florida, Gainesville, Florida 32610 and
| | - Gonzalo E Torres
- Pharmacology and Experimental Therapeutics, College of Medicine, University of Florida, Gainesville, Florida 32610 and
| | - Habibeh Khoshbouei
- From the Departments of Neuroscience and .,T32 in Movement Disorders and Neurorestoration, Fixel Center for Neurological Diseases, UF Health, Gainesville, Florida 32610
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