title: Prolonged treatment with pramipexole promotes physical interaction of striatal dopamine D3 autoreceptors with dopamine transporters to reduce dopamine uptake.
abstract: The dopamine (DA) transporter (DAT), a membrane glycoprotein expressed in dopaminergic neurons, clears DA from extracellular space and is regulated by diverse presynaptic proteins like protein kinases, α-synuclein, D2 and D3 autoreceptors. DAT dysfunction is implicated in Parkinson's disease and depression, which are therapeutically treated by dopaminergic D2/D3 receptor (D2/D3R) agonists. It is, then, important to improve our understanding of interactions between D3R and DAT. We show that prolonged administration of pramipexole (0.1mg/kg/day, 6 to 21 days), a preferential D3R agonist, leads to a decrease in DA uptake in mouse striatum that reflects a reduction in DAT affinity for DA in the absence of any change in DAT density or subcellular distribution. The effect of pramipexole was absent in mice with genetically-deleted D3R (D3R(-/-)), yet unaffected in mice genetically deprived of D2R (D2R(-/-)). Pramipexole treatment induced a physical interaction between D3R and DAT, as assessed by co-immunoprecipitation and in situ proximity ligation assay. Furthermore, it promoted the formation of DAT dimers and DAT association with both D2R and α-synuclein, effects that were abolished in D3R(-/-) mice, yet unaffected in D2R(-/-) mice, indicating dependence upon D3R. Collectively, these data suggest that prolonged treatment with dopaminergic D3 agonists provokes a reduction in DA reuptake by dopaminergic neurons related to a hitherto-unsuspected modification of the DAT interactome. These observations provide novel insights into the long-term antiparkinson, antidepressant and additional clinical actions of pramipexole and other D3R agonists.
authors.affiliation: Departamento de Anatomía, Facultad de Medicina, Instituto de Tecnologías Biomédicas (ITB, CIBICAN), Universidad de La Laguna, Tenerife, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Castro-Hernández
authors.affiliation: Departamento de Anatomía, Facultad de Medicina, Instituto de Tecnologías Biomédicas (ITB, CIBICAN), Universidad de La Laguna, Tenerife, Spain.
authors.forename: Domingo
authors.initials: D
authors.lastname: Afonso-Oramas
authors.affiliation: Departamento de Anatomía, Facultad de Medicina, Instituto de Tecnologías Biomédicas (ITB, CIBICAN), Universidad de La Laguna, Tenerife, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Cruz-Muros
authors.affiliation: Departamento de Anatomía, Facultad de Medicina, Instituto de Tecnologías Biomédicas (ITB, CIBICAN), Universidad de La Laguna, Tenerife, Spain.
authors.forename: Josmar
authors.initials: J
authors.lastname: Salas-Hernández
authors.affiliation: Departamento de Anatomía, Facultad de Medicina, Instituto de Tecnologías Biomédicas (ITB, CIBICAN), Universidad de La Laguna, Tenerife, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Barroso-Chinea
authors.affiliation: Departamento de Biología Funcional y de Sistemas, Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain; Centro de investigación Biomédica en Red sobre enfermedades neurodegenerativas, CIBERNED, Instituto de Salud Carlos III, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Moratalla
authors.affiliation: Pole of Innovation in Neuropsychopharmacology, Institut de Recherches Servier, 78290 Croissy sur Seine, France.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Millan
authors.affiliation: Departamento de Anatomía, Facultad de Medicina, Instituto de Tecnologías Biomédicas (ITB, CIBICAN), Universidad de La Laguna, Tenerife, Spain; Centro de investigación Biomédica en Red sobre enfermedades neurodegenerativas, CIBERNED, Instituto de Salud Carlos III, Spain. Electronic address: tgonhern@ull.es.
authors.forename: Tomás
authors.initials: T
authors.lastname: González-Hernández
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology; D000978:Antiparkinson Agents / Q000494:pharmacology; D017660:Autoreceptors / Q000378:metabolism*; D052160:Benzothiazoles / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D019281:Dimerization; D004298:Dopamine / Q000378:metabolism*; D018491:Dopamine Agonists / Q000494:pharmacology*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D000077487:Pramipexole; D050637:Receptors, Dopamine D3 / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D051844:alpha-Synuclein / Q000378:metabolism
chemical_list: D000928:Antidepressive Agents; D000978:Antiparkinson Agents; D017660:Autoreceptors; D052160:Benzothiazoles; D018491:Dopamine Agonists; D050483:Dopamine Plasma Membrane Transport Proteins; C493594:Drd3 protein, mouse; D050637:Receptors, Dopamine D3; C497605:Snca protein, mouse; D051844:alpha-Synuclein; D000077487:Pramipexole; D004298:Dopamine
keywords: D(2)R; D(3)R; Depression; Dopamine autoreceptor; Dopamine transporter; Multi-protein complex; Neuroprotection; Parkinson's disease