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Boudries R, Williams H, Paquereau-Gaboreau S, Bashir S, Hojjat Jodaylami M, Chisanga M, Trudeau LÉ, Masson JF. Surface-Enhanced Raman Scattering Nanosensing and Imaging in Neuroscience. ACS NANO 2024; 18:22620-22647. [PMID: 39088751 DOI: 10.1021/acsnano.4c05200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/03/2024]
Abstract
Monitoring neurochemicals and imaging the molecular content of brain tissues in vitro, ex vivo, and in vivo is essential for enhancing our understanding of neurochemistry and the causes of brain disorders. This review explores the potential applications of surface-enhanced Raman scattering (SERS) nanosensors in neurosciences, where their adoption could lead to significant progress in the field. These applications encompass detecting neurotransmitters or brain disorders biomarkers in biofluids with SERS nanosensors, and imaging normal and pathological brain tissues with SERS labeling. Specific studies highlighting in vitro, ex vivo, and in vivo analysis of brain disorders using fit-for-purpose SERS nanosensors will be detailed, with an emphasis on the ability of SERS to detect clinically pertinent levels of neurochemicals. Recent advancements in designing SERS-active nanomaterials, improving experimentation in biofluids, and increasing the usage of machine learning for interpreting SERS spectra will also be discussed. Furthermore, we will address the tagging of tissues presenting pathologies with nanoparticles for SERS imaging, a burgeoning domain of neuroscience that has been demonstrated to be effective in guiding tumor removal during brain surgery. The review also explores future research applications for SERS nanosensors in neuroscience, including monitoring neurochemistry in vivo with greater penetration using surface-enhanced spatially offset Raman scattering (SESORS), near-infrared lasers, and 2-photon techniques. The article concludes by discussing the potential of SERS for investigating the effectiveness of therapies for brain disorders and for integrating conventional neurochemistry techniques with SERS sensing.
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Affiliation(s)
- Ryma Boudries
- Department of Chemistry, Institut Courtois, Quebec Center for Advanced Materials (QCAM), and Regroupement Québécois sur les Matériaux de Pointe (RQMP), Université de Montréal, C.P. 6128 Succ. Centre-Ville, Montréal, Quebec H3C 3J7, Canada
| | - Hannah Williams
- Department of Chemistry, Institut Courtois, Quebec Center for Advanced Materials (QCAM), and Regroupement Québécois sur les Matériaux de Pointe (RQMP), Université de Montréal, C.P. 6128 Succ. Centre-Ville, Montréal, Quebec H3C 3J7, Canada
| | - Soraya Paquereau-Gaboreau
- Department of Chemistry, Institut Courtois, Quebec Center for Advanced Materials (QCAM), and Regroupement Québécois sur les Matériaux de Pointe (RQMP), Université de Montréal, C.P. 6128 Succ. Centre-Ville, Montréal, Quebec H3C 3J7, Canada
- Department of Pharmacology and Physiology, Department of Neurosciences, Faculty of Medicine, Université de Montréal, C.P. 6128 Succ. Centre-ville, Montréal, Quebec H3C 3J7, Canada
- Neural Signalling and Circuitry Research Group (SNC), Center for Interdisciplinary Research on the Brain and Learning (CIRCA), Université de Montréal, C.P. 6128 Succ. Centre-ville, Montréal, Quebec H3C 3J7, Canada
| | - Saba Bashir
- Department of Chemistry, Institut Courtois, Quebec Center for Advanced Materials (QCAM), and Regroupement Québécois sur les Matériaux de Pointe (RQMP), Université de Montréal, C.P. 6128 Succ. Centre-Ville, Montréal, Quebec H3C 3J7, Canada
| | - Maryam Hojjat Jodaylami
- Department of Chemistry, Institut Courtois, Quebec Center for Advanced Materials (QCAM), and Regroupement Québécois sur les Matériaux de Pointe (RQMP), Université de Montréal, C.P. 6128 Succ. Centre-Ville, Montréal, Quebec H3C 3J7, Canada
| | - Malama Chisanga
- Department of Chemistry, Institut Courtois, Quebec Center for Advanced Materials (QCAM), and Regroupement Québécois sur les Matériaux de Pointe (RQMP), Université de Montréal, C.P. 6128 Succ. Centre-Ville, Montréal, Quebec H3C 3J7, Canada
| | - Louis-Éric Trudeau
- Department of Pharmacology and Physiology, Department of Neurosciences, Faculty of Medicine, Université de Montréal, C.P. 6128 Succ. Centre-ville, Montréal, Quebec H3C 3J7, Canada
- Neural Signalling and Circuitry Research Group (SNC), Center for Interdisciplinary Research on the Brain and Learning (CIRCA), Université de Montréal, C.P. 6128 Succ. Centre-ville, Montréal, Quebec H3C 3J7, Canada
| | - Jean-Francois Masson
- Department of Chemistry, Institut Courtois, Quebec Center for Advanced Materials (QCAM), and Regroupement Québécois sur les Matériaux de Pointe (RQMP), Université de Montréal, C.P. 6128 Succ. Centre-Ville, Montréal, Quebec H3C 3J7, Canada
- Neural Signalling and Circuitry Research Group (SNC), Center for Interdisciplinary Research on the Brain and Learning (CIRCA), Université de Montréal, C.P. 6128 Succ. Centre-ville, Montréal, Quebec H3C 3J7, Canada
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Chen SJ, Cho RL, Yeh SHH, Tsai MC, Chuang YP, Lien CF, Chiu CH, Yeh YW, Lin CS, Ma KH. Pitavastatin attenuates hypercholesterolemia-induced decline in serotonin transporter availability. Lipids Health Dis 2024; 23:250. [PMID: 39154177 PMCID: PMC11330603 DOI: 10.1186/s12944-024-02236-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 08/01/2024] [Indexed: 08/19/2024] Open
Abstract
INTRODUCTION Hypercholesterolemia is associated with increased inflammation and impaired serotonin neurotransmission, potentially contributing to depressive symptoms. However, the role of statins, particularly pitavastatin, in modulating serotonin transporter (SERT) function within this context remains underexplored. This study aimed to investigate whether pitavastatin counteracts the neurobiological effects of hypercholesterolemia. METHODS Low-density lipoprotein receptor knockout (LDLR-/-) mice on a C57BL/6 background were assigned to three groups: a control group fed a standard chow diet, a group fed a high-fat diet (HFD), and a third group fed a high-fat diet supplemented with pitavastatin (HFD + Pita). We evaluated the effects of HFD with or without pitavastatin on lipid profiles, inflammatory markers, and SERT availability using small-animal positron emission tomography (PET) scans with the radioligand 4-[18F]-ADAM over a 20-week period. RESULTS Pitavastatin treatment in HFD-fed mice significantly reduced both total cholesterol and LDL cholesterol levels in HFD-fed mice compared to those on HFD alone. Elevated inflammatory markers such as IL-1α, MCP-1/CCL2, and TNF-α in HFD mice were notably decreased in the HFD + Pita group. PET scans showed reduced SERT availability in the brains of HFD mice; however, pitavastatin improved this in brain regions associated with mood regulation, suggesting enhanced serotonin neurotransmission. Additionally, the sucrose preference test showed a trend towards increased preference in the HFD + Pita group compared to the HFD group, indicating a potential reduction in depressive-like behavior. CONCLUSION Our findings demonstrate that pitavastatin not only lowers cholesterol and reduces inflammation but also enhances SERT availability, suggesting a potential role in alleviating depressive symptoms associated with hypercholesterolemia. These results highlight the multifaceted benefits of pitavastatin, extending beyond its lipid-lowering effects to potentially improving mood regulation and neurotransmitter function.
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Affiliation(s)
- Sy-Jou Chen
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, 114, Taiwan.
| | - Rou-Ling Cho
- Division of Cardiology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, 114, Taiwan
| | - Skye Hsin-Hsien Yeh
- School of Medicine, National Defense Medical Center, Taipei, Taiwan
- Brain Research Center, National Yang Ming Chaio Tung University, Taipei, Taiwan
| | - Min-Chien Tsai
- Department of Physiology and Biophysics, Graduate Institute of Physiology, National Defense Medical Center, Taipei, Taiwan
| | - Yi-Ping Chuang
- Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan
- Graduate Institute of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan
| | - Chih-Feng Lien
- Division of Cardiology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, 114, Taiwan
| | - Chuang-Hsin Chiu
- Department of Nuclear Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yi-Wei Yeh
- Department of Psychiatry, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chin-Sheng Lin
- Division of Cardiology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, 114, Taiwan.
| | - Kuo-Hsing Ma
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, 114, Taiwan.
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Chan MC, Procko E, Shukla D. Structural Rearrangement of the Serotonin Transporter Intracellular Gate Induced by Thr276 Phosphorylation. ACS Chem Neurosci 2022; 13:933-945. [PMID: 35258286 DOI: 10.1021/acschemneuro.1c00714] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The reuptake of the neurotransmitter serotonin from the synaptic cleft by the serotonin transporter, SERT, is essential for proper neurological signaling. Biochemical studies have shown that Thr276 of transmembrane helix 5 is a site of PKG-mediated SERT phosphorylation, which has been proposed to shift the SERT conformational equilibria to promote inward-facing states, thus enhancing 5-HT transport. Recent structural and simulation studies have provided insights into the conformation transitions during substrate transport but have not shed light on SERT regulation via post-translational modifications. Using molecular dynamics simulations and Markov state models, we investigate how Thr276 phosphorylation impacts the SERT mechanism and its role in enhancing transporter stability and function. Our simulations show that Thr276 phosphorylation alters the hydrogen-bonding network involving residues on transmembrane helix 5. This in turn decreases the free energy barriers for SERT to transition to the inward-facing state, thus facilitating 5-HT import. The results provide atomistic insights into in vivo SERT regulation and can be extended to other pharmacologically important transporters in the solute carrier family.
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Affiliation(s)
- Matthew C. Chan
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Erik Procko
- Department of Biochemistry, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Center for Biophysics and Quantitative Biology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Neuroscience Program, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Cancer Center at Illinois, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Diwakar Shukla
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Center for Biophysics and Quantitative Biology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Cancer Center at Illinois, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- National Center for Supercomputing Applications, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Department of Bioengineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
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Tomlinson ID, Kovtun O, Torres R, Bellocchio LG, Josephs T, Rosenthal SJ. A Novel Biotinylated Homotryptamine Derivative for Quantum Dot Imaging of Serotonin Transporter in Live Cells. Front Cell Neurosci 2021; 15:667044. [PMID: 34867196 PMCID: PMC8637195 DOI: 10.3389/fncel.2021.667044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 10/19/2021] [Indexed: 11/21/2022] Open
Abstract
The serotonin transporter (SERT) is the primary target for selective serotonin reuptake inhibitor (SSRI) antidepressants that are thought to exert their therapeutic effects by increasing the synaptic concentration of serotonin. Consequently, probes that can be utilized to study cellular trafficking of SERT are valuable research tools. We have developed a novel ligand (IDT785) that is composed of a SERT antagonist (a tetrahydro pyridyl indole derivative) conjugated to a biotinylated poly ethylene glycol (PEG) via a phenethyl linker. This compound was determined to be biologically active and inhibited SERT-mediated reuptake of IDT307 with the half-maximal inhibitory concentration of 7.2 ± 0.3 μM. We demonstrated that IDT785 enabled quantum dot (QD) labeling of membrane SERT in transfected HEK-293 cultures that could be blocked using the high affinity serotonin reuptake inhibitor paroxetine. Molecular docking studies suggested that IDT785 might be binding to the extracellular vestibule binding site rather than the orthosteric substrate binding site, which could be attributable to the hydrophilicity of the PEG chain and the increased loss of degrees of freedom that would be required to penetrate into the orthosteric binding site. Using IDT785, we were able to study the membrane localization and membrane dynamics of YFP-SERT heterologously expressed in HEK-293 cells and demonstrated that SERT expression was enriched in the membrane edge and in thin cellular protrusions.
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Affiliation(s)
- Ian D. Tomlinson
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Oleg Kovtun
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Ruben Torres
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States
| | | | - Travis Josephs
- Neuroscience Program, Vanderbilt University, Nashville, TN, United States
| | - Sandra J. Rosenthal
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Nashville, TN, United States
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Kovtun O, Torres R, Ferguson RS, Josephs T, Rosenthal SJ. Single Quantum Dot Tracking Unravels Agonist Effects on the Dopamine Receptor Dynamics. Biochemistry 2021; 60:1031-1043. [PMID: 32584548 DOI: 10.1021/acs.biochem.0c00360] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
D2 dopamine receptors (DRD2s) belong to a family of G protein-coupled receptors that modulate synaptic dopaminergic tone via regulation of dopamine synthesis, storage, and synaptic release. DRD2s are the primary target for traditional antipsychotic medications; dysfunctional DRD2 signaling has been linked to major depressive disorder, attention-deficit hyperactivity disorder, addiction, Parkinson's, and schizophrenia. DRD2 lateral diffusion appears to be an important post-translational regulatory mechanism; however, the dynamic response of DRD2s to ligand-induced activation is poorly understood. Dynamic imaging of the long isoform of DRD2 (D2L) fused to an N-terminal antihemagglutinin (HA) epitope and transiently expressed in HEK-293 cells was achieved through a combination of a high-affinity biotinylated anti-HA antigen-binding fragment (Fab) and streptavidin-conjugated quantum dots (QD). Significant reduction (∼40%) in the rate of lateral diffusion of QD-tagged D2L proteins was observed under agonist (quinpirole; QN)-stimulated conditions compared to basal conditions. QN-induced diffusional slowing was accompanied by an increase in frequency, lifetime, and confinement of temporary arrest of lateral diffusion (TALL), an intrinsic property of single receptor lateral motion. The role of the actin cytoskeleton in QN-induced diffusional slowing of D2L was also explored. The observed dynamic changes appear to be a sensitive indicator of the receptor activity status and might also spatially and temporally shape the receptor-mediated downstream signaling. This dynamic information could potentially be useful in informing drug discovery efforts based on single-molecule pharmacology.
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Affiliation(s)
- Oleg Kovtun
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Ruben Torres
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Riley S Ferguson
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Travis Josephs
- Neuroscience Program, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Sandra J Rosenthal
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37240, United States
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37240, United States
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37240, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
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Quantitative Analysis of Single Quantum Dot Trajectories. Methods Mol Biol 2020. [PMID: 32246331 DOI: 10.1007/978-1-0716-0463-2_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Single quantum dot tracking (SQDT) is a powerful technique for interrogating biomolecular dynamics in living cells and tissue. SQDT has particularly excelled in driving discovery at the single-molecule level in the fields of neuronal communication, plasma membrane organization, viral infection, and immune system response. Here, we briefly characterize various elements of the SQDT analytical framework and provide the reader with a detailed set of executable commands to implement commonly used algorithms for SQDT data processing.
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Thal LB, Mann VR, Sprinzen D, McBride JR, Reid KR, Tomlinson ID, McMahon DG, Cohen BE, Rosenthal SJ. Ligand-conjugated quantum dots for fast sub-diffraction protein tracking in acute brain slices. Biomater Sci 2020; 8:837-845. [PMID: 31790090 PMCID: PMC7002256 DOI: 10.1039/c9bm01629e] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Semiconductor quantum dots (QDs) have demonstrated utility in long-term single particle tracking of membrane proteins in live cells in culture. To extend the superior optical properties of QDs to more physiologically relevant cell platforms, such as acute brain slices, we examine the photophysics of compact ligand-conjugated CdSe/CdS QDs using both ensemble and single particle analysis in brain tissue media. We find that symmetric core passivation is critical for both photostability in oxygenated media and for prolonged single particle imaging in brain slices. We then demonstrate the utility of these QDs by imaging single dopamine transporters in acute brain slices, achieving 20 nm localization precision at 10 Hz frame rates. These findings detail design requirements needed for new QD probes in complex living environments, and open the door to physiologically relevant studies that capture the utility of QD probes in acute brain slices.
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Affiliation(s)
- Lucas B Thal
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA.
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Thal LB, Kovtun O, Rosenthal SJ. Labeling Neuronal Proteins with Quantum Dots for Single-Molecule Imaging. Methods Mol Biol 2020; 2135:169-177. [PMID: 32246334 DOI: 10.1007/978-1-0716-0463-2_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Single-molecule imaging has illuminated dynamics and kinetics of neuronal proteins in their native membranes helping us understand their effective roles in the brain. Here, we describe how nanometer-sized fluorescent semiconductors called quantum dots (QD) can be used to label neuronal proteins in a single QD imaging format. We detail two generalizable protocols accompanied by experimental considerations giving the user options in approach tailored to the materials and equipment available. These protocols can be modified for experiments to verify target specificity, as well as single molecule analysis such as single particle tracking and protein clustering.
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Affiliation(s)
- Lucas B Thal
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
| | - Oleg Kovtun
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Sandra J Rosenthal
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA.
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA.
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, USA.
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA.
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Kovtun O, Tomlinson ID, Ferguson RS, Rosenthal SJ. Quantum dots reveal heterogeneous membrane diffusivity and dynamic surface density polarization of dopamine transporter. PLoS One 2019; 14:e0225339. [PMID: 31751387 PMCID: PMC6872175 DOI: 10.1371/journal.pone.0225339] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/01/2019] [Indexed: 12/11/2022] Open
Abstract
The presynaptic dopamine transporter mediates rapid reuptake of synaptic dopamine. Although cell surface DAT trafficking recently emerged as an important component of DAT regulation, it has not been systematically investigated. Here, we apply our single quantum dot (Qdot) tracking approach to monitor DAT plasma membrane dynamics in several heterologous expression cell hosts with nanometer localization accuracy. We demonstrate that Qdot-tagged DAT proteins exhibited highly heterogeneous membrane diffusivity dependent on the local membrane topography. We also show that Qdot-tagged DATs were localized away from the flat membrane regions and were dynamically retained in the membrane protrusions and cell edges for the duration of imaging. Single quantum dot tracking of wildtype DAT and its conformation-defective coding variants (R60A and W63A) revealed a significantly accelerated rate of dysfunctional DAT membrane diffusion. We believe our results warrant an in-depth investigation as to whether compromised membrane dynamics is a common feature of brain disorder-derived DAT mutants.
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Affiliation(s)
- Oleg Kovtun
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Ian D. Tomlinson
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Riley S. Ferguson
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Sandra J. Rosenthal
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail:
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Quinlan MA, Krout D, Katamish RM, Robson MJ, Nettesheim C, Gresch PJ, Mash DC, Keith Henry L, Blakely RD. Human Serotonin Transporter Coding Variation Establishes Conformational Bias with Functional Consequences. ACS Chem Neurosci 2019; 10:3249-3260. [PMID: 30668912 PMCID: PMC6640095 DOI: 10.1021/acschemneuro.8b00689] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The antidepressant-sensitive serotonin (5-HT) transporter (SERT) dictates rapid, high-affinity clearance of the neurotransmitter in both the brain and periphery. In a study of families with multiple individuals diagnosed with autism spectrum disorder (ASD), we previously identified several, rare, missense coding variants that impart elevated 5-HT transport activity, relative to wild-type SERT, upon heterologous expression as well as in ASD subject lymphoblasts. The most common of these variants, SERT Ala56, located in the transporter's cytosolic N-terminus, has been found to confer in transgenic mice hyperserotonemia, an ASD-associated biochemical trait, an elevated brain 5-HT clearance rate, and ASD-aligned behavioral changes. Hyperfunction of SERT Ala56 has been ascribed to a change in 5-HT KM, though the physical basis of this change has yet to be elucidated. Through assessments of fluorescence resonance energy transfer (FRET) between cytosolic N- and C-termini, sensitivity to methanethiosulfonates, and capacity for N-terminal tryptic digestion, we obtain evidence for mutation-induced conformational changes that support an open-outward 5-HT binding conformation in vitro and in vivo. Aspects of these findings were also evident with another naturally occurring C-terminal SERT coding variant identified in our ASD study, Asn605. We conclude that biased conformations of surface resident transporters that can impact transporter function and regulation are an unappreciated consequence of heritable and disease-associated SERT coding variation.
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Affiliation(s)
- Meagan A. Quinlan
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN
- Department of Biomedical Science, Charles E. Schmidt College of Medicine
| | - Danielle Krout
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND
| | - Rania M. Katamish
- Department of Biomedical Science, Charles E. Schmidt College of Medicine
| | - Matthew J. Robson
- Division of Pharmaceutical Sciences, University of Cincinnati, Cincinnati, OH
| | | | - Paul J. Gresch
- Department of Biomedical Science, Charles E. Schmidt College of Medicine
- Brain Institute, Florida Atlantic University, Jupiter, FL
| | - Deborah C. Mash
- Dr. Kiran Patel College of Allopathic Medicine, Nova Southeastern University, Davie, FL
| | - L. Keith Henry
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND
| | - Randy D. Blakely
- Department of Biomedical Science, Charles E. Schmidt College of Medicine
- Brain Institute, Florida Atlantic University, Jupiter, FL
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Tomlinson ID, Kovtun O, Crescentini TM, Rosenthal SJ. Biotinylated-spiperone ligands for quantum dot labeling of the dopamine D2 receptor in live cell cultures. Bioorg Med Chem Lett 2019; 29:959-964. [DOI: 10.1016/j.bmcl.2019.02.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/19/2019] [Accepted: 02/21/2019] [Indexed: 12/26/2022]
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Abstract
Quantum dots are nanometer-sized semiconductors that have size-tunable, narrow emission bands, high quantum yields, and are resistant to photobleaching. Ligand-conjugated quantum dots enable the real time visualization of membrane proteins and have revealed that membrane diffusion dynamics are intrinsic to protein regulation, are susceptible to the level of membrane cholesterol, and are altered in genetic variants linked to disease, suggesting a mise en place approach to neuropsychopharmacology.
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Affiliation(s)
- Sandra J. Rosenthal
- Department of Chemistry, Department of Physics and Astronomy, Department of Pharmacology, and the Department of Chemical and Biomolecular Engineering, and Vanderbilt Institute of Nanoscale Science and Engineering Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, United States
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Thal LB, Tomlinson ID, Quinlan MA, Kovtun O, Blakely RD, Rosenthal SJ. Single Quantum Dot Imaging Reveals PKCβ-Dependent Alterations in Membrane Diffusion and Clustering of an Attention-Deficit Hyperactivity Disorder/Autism/Bipolar Disorder-Associated Dopamine Transporter Variant. ACS Chem Neurosci 2019; 10:460-471. [PMID: 30153408 PMCID: PMC6411462 DOI: 10.1021/acschemneuro.8b00350] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The dopamine transporter (DAT) is a transmembrane protein that terminates dopamine signaling in the brain by driving rapid dopamine reuptake into presynaptic nerve terminals. Several lines of evidence indicate that DAT dysfunction is linked to neuropsychiatric disorders such as attention-deficit/hyperactivity disorder (ADHD), bipolar disorder (BPD), and autism spectrum disorder (ASD). Indeed, individuals with these disorders have been found to express the rare, functional DAT coding variant Val559, which confers anomalous dopamine efflux (ADE) in vitro and in vivo. To elucidate the impact of the DAT Val559 variant on membrane diffusion dynamics, we implemented our antagonist-conjugated quantum dot (QD) labeling approach to monitor the lateral mobility of single particle-labeled transporters in transfected HEK-293 and SK-N-MC cells. Our results demonstrate significantly higher diffusion coefficients of DAT Val559 compared to those of DAT Ala559, effects likely determined by elevated N-terminal transporter phosphorylation. We also provide pharmacological evidence that PKCβ-mediated signaling supports enhanced DAT Val559 membrane diffusion rates. Additionally, our results are complimented with diffusion rates of phosphomimicked and phosphorylation-occluded DAT variants. Furthermore, we show DAT Val559 has a lower propensity for membrane clustering, which may be caused by a mutation-derived shift out of membrane microdomains leading to faster lateral membrane diffusion rates. These findings further demonstrate a functional impact of DAT Val559 and suggest that changes in transporter localization and lateral mobility may sustain ADE and contribute to alterations in dopamine signaling underlying multiple neuropsychiatric disorders.
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