Dopamine D2 Long Receptors Are Critical for Caveolae-Mediated α-Synuclein Uptake in Cultured Dopaminergic Neurons
Ichiro Kawahata,
Tomoki Sekimori,
Haoyang Wang,
Yanyan Wang,
Toshikuni Sasaoka,
Luc Bousset,
Ronald Melki,
Tomohiro Mizobata,
Yasushi Kawata,
Kohji Fukunaga
Affiliations
Ichiro Kawahata
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
Tomoki Sekimori
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
Haoyang Wang
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
Yanyan Wang
Department of Pharmaceutical Sciences, Ben and Maytee Fisch College of Pharmacy, University of Texas at Tyler, 3900 University Blvd, Tyler, TX 75799, USA
Toshikuni Sasaoka
Department of Comparative and Experimental Medicine, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
Luc Bousset
Laboratory of Neurodegenerative Diseases, Institut François Jacob (MIRcen), Centre National de la Recherche Scientifique (CNRS), Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA), 18 Route du Panorama, 92265 Fontenay-aux-Roses, France
Ronald Melki
Laboratory of Neurodegenerative Diseases, Institut François Jacob (MIRcen), Centre National de la Recherche Scientifique (CNRS), Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA), 18 Route du Panorama, 92265 Fontenay-aux-Roses, France
Tomohiro Mizobata
Department of Chemistry and Biotechnology, Graduate School of Engineering Tottori University, Tottori 680-8550, Japan
Yasushi Kawata
Department of Chemistry and Biotechnology, Graduate School of Engineering Tottori University, Tottori 680-8550, Japan
Kohji Fukunaga
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
α-synuclein accumulation into dopaminergic neurons is a pathological hallmark of Parkinson’s disease. We previously demonstrated that fatty acid-binding protein 3 (FABP3) is critical for α-synuclein uptake and propagation to accumulate in dopaminergic neurons. FABP3 is abundant in dopaminergic neurons and interacts with dopamine D2 receptors, specifically the long type (D2L). Here, we investigated the importance of dopamine D2L receptors in the uptake of α-synuclein monomers and their fibrils. We employed mesencephalic neurons derived from dopamine D2L−/−, dopamine D2 receptor null (D2 null), FABP3−/−, and wild type C57BL6 mice, and analyzed the uptake ability of fluorescence-conjugated α-synuclein monomers and fibrils. We found that D2L receptors are co-localized with FABP3. Immunocytochemistry revealed that TH+ D2L−/− or D2 null neurons do not take up α-synuclein monomers. The deletion of α-synuclein C-terminus completely abolished the uptake to dopamine neurons. Likewise, dynasore, a dynamin inhibitor, and caveolin-1 knockdown also abolished the uptake. D2L and FABP3 were also critical for α-synuclein fibrils uptake. D2L and accumulated α-synuclein fibrils were well co-localized. These data indicate that dopamine D2L with a caveola structure coupled with FABP3 is critical for α-synuclein uptake by dopaminergic neurons, suggesting a novel pathogenic mechanism of synucleinopathies, including Parkinson’s disease.
