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Bhatt M, Lazzarin E, Alberto-Silva AS, Domingo G, Zerlotti R, Gradisch R, Bazzone A, Sitte HH, Stockner T, Bossi E. Unveiling the crucial role of betaine: modulation of GABA homeostasis via SLC6A1 transporter (GAT1). Cell Mol Life Sci 2024; 81:269. [PMID: 38884791 DOI: 10.1007/s00018-024-05309-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 06/18/2024]
Abstract
Betaine is an endogenous osmolyte that exhibits therapeutic potential by mitigating various neurological disorders. However, the underlying cellular and molecular mechanisms responsible for its neuroprotective effects remain puzzling.In this study, we describe a possible mechanism behind the positive impact of betaine in preserving neurons from excitotoxicity. Here we demonstrate that betaine at low concentration modulates the GABA uptake by GAT1 (slc6a1), the predominant GABA transporter in the central nervous system. This modulation occurs through the temporal inhibition of the transporter, wherein prolonged occupancy by betaine impedes the swift transition of the transporter to the inward conformation. Importantly, the modulatory effect of betaine on GAT1 is reversible, as the blocking of GAT1 disappears with increased extracellular GABA. Using electrophysiology, mass spectroscopy, radiolabelled cellular assay, and molecular dynamics simulation we demonstrate that betaine has a dual role in GAT1: at mM concentration acts as a slow substrate, and at µM as a temporal blocker of GABA, when it is below its K0.5. Given this unique modulatory characteristic and lack of any harmful side effects, betaine emerges as a promising neuromodulator of the inhibitory pathways improving GABA homeostasis via GAT1, thereby conferring neuroprotection against excitotoxicity.
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Affiliation(s)
- Manan Bhatt
- Department of Biotechnology and Life Science, Laboratory of Cellular and Molecular Physiology, University of Insubria, Via J. H. Dunant 3, 21100, Varese, Italy
| | - Erika Lazzarin
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Ana Sofia Alberto-Silva
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Guido Domingo
- Department of Biotechnology and Life Science, Laboratory of Cellular and Molecular Physiology, University of Insubria, Via J. H. Dunant 3, 21100, Varese, Italy
| | - Rocco Zerlotti
- Nanion Technologies GmbH, Ganghoferstr. 70a, 80339, Munich, Germany
| | - Ralph Gradisch
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Andre Bazzone
- Nanion Technologies GmbH, Ganghoferstr. 70a, 80339, Munich, Germany
| | - Harald H Sitte
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
- Hourani Center for Applied Scientific Research, Al-Ahliyya Amman University, Amman, 19328, Jordan
- Center for Addiction Research and Science, Medical University of Vienna, 1090, Vienna, Austria
| | - Thomas Stockner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Elena Bossi
- Department of Biotechnology and Life Science, Laboratory of Cellular and Molecular Physiology, University of Insubria, Via J. H. Dunant 3, 21100, Varese, Italy.
- Centre for Neuroscience, University of Insubria, 21100, Varese, Italy.
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2
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Silva DB, Trinidad M, Ljungdahl A, Revalde JL, Berguig GY, Wallace W, Patrick CS, Bomba L, Arkin M, Dong S, Estrada K, Hutchinson K, LeBowitz JH, Schlessinger A, Johannesen KM, Møller RS, Giacomini KM, Froelich S, Sanders SJ, Wuster A. Haploinsufficiency underlies the neurodevelopmental consequences of SLC6A1 variants. Am J Hum Genet 2024; 111:1222-1238. [PMID: 38781976 PMCID: PMC11179425 DOI: 10.1016/j.ajhg.2024.04.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 04/26/2024] [Accepted: 04/26/2024] [Indexed: 05/25/2024] Open
Abstract
Heterozygous variants in SLC6A1, encoding the GAT-1 GABA transporter, are associated with seizures, developmental delay, and autism. The majority of affected individuals carry missense variants, many of which are recurrent germline de novo mutations, raising the possibility of gain-of-function or dominant-negative effects. To understand the functional consequences, we performed an in vitro GABA uptake assay for 213 unique variants, including 24 control variants. De novo variants consistently resulted in a decrease in GABA uptake, in keeping with haploinsufficiency underlying all neurodevelopmental phenotypes. Where present, ClinVar pathogenicity reports correlated well with GABA uptake data; the functional data can inform future reports for the remaining 72% of unscored variants. Surface localization was assessed for 86 variants; two-thirds of loss-of-function missense variants prevented GAT-1 from being present on the membrane while GAT-1 was on the surface but with reduced activity for the remaining third. Surprisingly, recurrent de novo missense variants showed moderate loss-of-function effects that reduced GABA uptake with no evidence for dominant-negative or gain-of-function effects. Using linear regression across multiple missense severity scores to extrapolate the functional data to all potential SLC6A1 missense variants, we observe an abundance of GAT-1 residues that are sensitive to substitution. The extent of this missense vulnerability accounts for the clinically observed missense enrichment; overlap with hypermutable CpG sites accounts for the recurrent missense variants. Strategies to increase the expression of the wild-type SLC6A1 allele are likely to be beneficial across neurodevelopmental disorders, though the developmental stage and extent of required rescue remain unknown.
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Affiliation(s)
- Dina Buitrago Silva
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Marena Trinidad
- BioMarin Pharmaceutical Inc., Novato, CA, USA; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Alicia Ljungdahl
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA; Institute of Developmental and Regenerative Medicine, Department of Paediatrics, University of Oxford, Oxford OX3 7TY, UK
| | - Jezrael L Revalde
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
| | | | | | - Cory S Patrick
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | | | - Michelle Arkin
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
| | - Shan Dong
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | | | - Keino Hutchinson
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | - Avner Schlessinger
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Katrine M Johannesen
- Department of Regional Health Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Rikke S Møller
- Department of Regional Health Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark; Department of Epilepsy Genetics and Personalized Medicine, Member of ERN Epicare, Danish Epilepsy Centre, Dianalund, Denmark
| | - Kathleen M Giacomini
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | | | - Stephan J Sanders
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA; Institute of Developmental and Regenerative Medicine, Department of Paediatrics, University of Oxford, Oxford OX3 7TY, UK.
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3
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Raut S, Singh K, Sanghvi S, Loyo-Celis V, Varghese L, Singh E, Gururaja Rao S, Singh H. Chloride ions in health and disease. Biosci Rep 2024; 44:BSR20240029. [PMID: 38573803 PMCID: PMC11065649 DOI: 10.1042/bsr20240029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 04/06/2024] Open
Abstract
Chloride is a key anion involved in cellular physiology by regulating its homeostasis and rheostatic processes. Changes in cellular Cl- concentration result in differential regulation of cellular functions such as transcription and translation, post-translation modifications, cell cycle and proliferation, cell volume, and pH levels. In intracellular compartments, Cl- modulates the function of lysosomes, mitochondria, endosomes, phagosomes, the nucleus, and the endoplasmic reticulum. In extracellular fluid (ECF), Cl- is present in blood/plasma and interstitial fluid compartments. A reduction in Cl- levels in ECF can result in cell volume contraction. Cl- is the key physiological anion and is a principal compensatory ion for the movement of the major cations such as Na+, K+, and Ca2+. Over the past 25 years, we have increased our understanding of cellular signaling mediated by Cl-, which has helped in understanding the molecular and metabolic changes observed in pathologies with altered Cl- levels. Here, we review the concentration of Cl- in various organs and cellular compartments, ion channels responsible for its transportation, and recent information on its physiological roles.
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Affiliation(s)
- Satish K. Raut
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Kulwinder Singh
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Shridhar Sanghvi
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
- Department of Molecular Cellular and Developmental Biology, The Ohio State University, Columbus, OH, U.S.A
| | - Veronica Loyo-Celis
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Liyah Varghese
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Ekam R. Singh
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | | | - Harpreet Singh
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
- Department of Molecular Cellular and Developmental Biology, The Ohio State University, Columbus, OH, U.S.A
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4
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Huang Y, Liu Y, Xiao X, Guo D, Zeng W, Luo Z. Evaluation of quality consistency between dispensing granules and traditional decoction of Bombyx batryticatus based on peptidomics and in silico simulations. Biomed Chromatogr 2024:e5906. [PMID: 38807034 DOI: 10.1002/bmc.5906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 04/16/2024] [Accepted: 05/09/2024] [Indexed: 05/30/2024]
Abstract
The application of traditional Chinese medicine dispensing granules is becoming increasingly prevalent. However, the consistency of dispensing granules with traditional decoction remains controversial. In this study, the consistency of peptide composition and pharmacodynamics between dispensing granules and traditional decoction of Bombyx batryticatus (BB) were assessed. A peptidomics method based on LC-tandem mass spectrometry technology was used to evaluate peptide composition similarity between BB traditional decoction and dispensing granules. The results revealed notable differences in peptide sequences between the two dosage forms, with only 8.55% of peptides shared between them. To evaluate the potential pharmacodynamic effects of the two dosage forms on epilepsy, virtual screening was used to identify potential active peptides, including blood-brain barrier permeability, toxicity prediction, and molecular docking. BB traditional decoction demonstrated a higher number and greater abundance of potential active peptides than BB dispensing granules, suggesting that BB traditional decoction may have a more favorable effect in treating epilepsy compared with BB dispensing granules. Moreover, molecular docking and molecular dynamics simulation studies confirmed the mechanism of action of active peptides to γ-aminobutyric acid transporter 1 (GAT-1). This study provides a scientific basis for the evaluation of quality consistency between BB traditional decoction and dispensing granules.
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Affiliation(s)
- Yayang Huang
- School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Yaxiong Liu
- NMPA Key Laboratory of Rapid Drug Inspection Technology, Guangzhou, China
- Guangdong Biomedical Technology Collaborative Innovation Center, Guangzhou, China
- Guangdong Institute for Drug Control, Guangzhou, China
| | - Xiaotong Xiao
- School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Dong Guo
- Guangdong Institute for Drug Control, Guangzhou, China
| | - Wenjie Zeng
- School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Zhuoya Luo
- NMPA Key Laboratory of Rapid Drug Inspection Technology, Guangzhou, China
- Guangdong Biomedical Technology Collaborative Innovation Center, Guangzhou, China
- Guangdong Institute for Drug Control, Guangzhou, China
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5
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Tran NL, Senko S, Lucier KW, Farwell AC, Silva SM, Dip PV, Poweleit N, Scapin G, Catalano C. High-Resolution Cryo-Electron Microscopy Structure Determination of Haemophilus influenzae Tellurite-Resistance Protein A via 200 kV Transmission Electron Microscopy. Int J Mol Sci 2024; 25:4528. [PMID: 38674110 PMCID: PMC11050165 DOI: 10.3390/ijms25084528] [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: 03/29/2024] [Revised: 04/16/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024] Open
Abstract
Membrane proteins constitute about 20% of the human proteome and play crucial roles in cellular functions. However, a complete understanding of their structure and function is limited by their hydrophobic nature, which poses significant challenges in purification and stabilization. Detergents, essential in the isolation process, risk destabilizing or altering the proteins' native conformations, thus affecting stability and functionality. This study leverages single-particle cryo-electron microscopy to elucidate the structural nuances of membrane proteins, focusing on the SLAC1 bacterial homolog from Haemophilus influenzae (HiTehA) purified with diverse detergents, including n-dodecyl β-D-maltopyranoside (DDM), glycodiosgenin (GDN), β-D-octyl-glucoside (OG), and lauryl maltose neopentyl glycol (LMNG). This research not only contributes to the understanding of membrane protein structures but also addresses detergent effects on protein purification. By showcasing that the overall structural integrity of the channel is preserved, our study underscores the intricate interplay between proteins and detergents, offering insightful implications for drug design and membrane biology.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Claudio Catalano
- NanoImaging Services, 4940 Carroll Canyon Road, Suite 115, San Diego, CA 92121, USA; (N.L.T.); (K.W.L.); (A.C.F.)
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6
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Galetin A, Brouwer KLR, Tweedie D, Yoshida K, Sjöstedt N, Aleksunes L, Chu X, Evers R, Hafey MJ, Lai Y, Matsson P, Riselli A, Shen H, Sparreboom A, Varma MVS, Yang J, Yang X, Yee SW, Zamek-Gliszczynski MJ, Zhang L, Giacomini KM. Membrane transporters in drug development and as determinants of precision medicine. Nat Rev Drug Discov 2024; 23:255-280. [PMID: 38267543 DOI: 10.1038/s41573-023-00877-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2023] [Indexed: 01/26/2024]
Abstract
The effect of membrane transporters on drug disposition, efficacy and safety is now well recognized. Since the initial publication from the International Transporter Consortium, significant progress has been made in understanding the roles and functions of transporters, as well as in the development of tools and models to assess and predict transporter-mediated activity, toxicity and drug-drug interactions (DDIs). Notable advances include an increased understanding of the effects of intrinsic and extrinsic factors on transporter activity, the application of physiologically based pharmacokinetic modelling in predicting transporter-mediated drug disposition, the identification of endogenous biomarkers to assess transporter-mediated DDIs and the determination of the cryogenic electron microscopy structures of SLC and ABC transporters. This article provides an overview of these key developments, highlighting unanswered questions, regulatory considerations and future directions.
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Affiliation(s)
- Aleksandra Galetin
- Centre for Applied Pharmacokinetic Research, School of Health Sciences, The University of Manchester, Manchester, UK.
| | - Kim L R Brouwer
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Kenta Yoshida
- Clinical Pharmacology, Genentech Research and Early Development, South San Francisco, CA, USA
| | - Noora Sjöstedt
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Lauren Aleksunes
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA
| | - Xiaoyan Chu
- Department of Pharmacokinetics, Dynamics, Metabolism, and Bioanalytics, Merck & Co., Inc., Rahway, NJ, USA
| | - Raymond Evers
- Preclinical Sciences and Translational Safety, Johnson & Johnson, Janssen Pharmaceuticals, Spring House, PA, USA
| | - Michael J Hafey
- Department of Pharmacokinetics, Dynamics, Metabolism, and Bioanalytics, Merck & Co., Inc., Rahway, NJ, USA
| | - Yurong Lai
- Drug Metabolism, Gilead Sciences Inc., Foster City, CA, USA
| | - Pär Matsson
- Department of Pharmacology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Andrew Riselli
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Hong Shen
- Department of Drug Metabolism and Pharmacokinetics, Bristol Myers Squibb Research and Development, Princeton, NJ, USA
| | - Alex Sparreboom
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH, USA
| | - Manthena V S Varma
- Pharmacokinetics, Dynamics and Metabolism, Medicine Design, Worldwide R&D, Pfizer Inc, Groton, CT, USA
| | - Jia Yang
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Xinning Yang
- Office of Clinical Pharmacology, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Sook Wah Yee
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | | | - Lei Zhang
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Kathleen M Giacomini
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA.
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7
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Li SY, Shi WJ, Ma DD, Zhang JG, Lu ZJ, Long XB, Liu X, Huang CS, Ying GG. Effects of New Psychoactive Substance Esketamine on Behaviors and Transcription of Genes in Dopamine and GABA Pathways in Zebrafish Larvae. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2024; 112:51. [PMID: 38556558 DOI: 10.1007/s00128-024-03883-0] [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] [Received: 10/20/2023] [Accepted: 03/07/2024] [Indexed: 04/02/2024]
Abstract
Esketamine (ESK) is the S-enantiomer of ketamine racemate (a new psychoactive substance) that can result in illusions, and alter hearing, vision, and proprioception in human and mouse. Up to now, the neurotoxicity caused by ESK at environmental level in fish is still unclear. This work studied the effects of ESK on behaviors and transcriptions of genes in dopamine and GABA pathways in zebrafish larvae at ranging from 12.4 ng L- 1 to 11141.1 ng L- 1 for 7 days post fertilization (dpf). The results showed that ESK at 12.4 ng L- 1 significantly reduced the touch response of the larvae at 48 hpf. ESK at 12.4 ng L- 1 also reduced the time and distance of larvae swimming at the outer zone during light period, which implied that ESK might potentially decrease the anxiety level of larvae. In addition, ESK increased the transcription of th, ddc, drd1a, drd3 and drd4a in dopamine pathway. Similarly, ESK raised the transcription of slc6a1b, slc6a13 and slc12a2 in GABA pathway. This study suggested that ESK could affect the heart rate and behaviors accompanying with transcriptional alterations of genes in DA and GABA pathways at early-staged zebrafish, which resulted in neurotoxicity in zebrafish larvae.
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Affiliation(s)
- Si-Ying Li
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, SCNU Environmental Research Institute, South China Normal University, Guangzhou, 510006, China
- School of Environment, South China Normal University, University Town, Guangzhou, 510006, China
| | - Wen-Jun Shi
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, SCNU Environmental Research Institute, South China Normal University, Guangzhou, 510006, China.
- School of Environment, South China Normal University, University Town, Guangzhou, 510006, China.
| | - Dong-Dong Ma
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, SCNU Environmental Research Institute, South China Normal University, Guangzhou, 510006, China
- School of Environment, South China Normal University, University Town, Guangzhou, 510006, China
| | - Jin-Ge Zhang
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, SCNU Environmental Research Institute, South China Normal University, Guangzhou, 510006, China
- School of Environment, South China Normal University, University Town, Guangzhou, 510006, China
| | - Zhi-Jie Lu
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, SCNU Environmental Research Institute, South China Normal University, Guangzhou, 510006, China
- School of Environment, South China Normal University, University Town, Guangzhou, 510006, China
| | - Xiao-Bing Long
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, SCNU Environmental Research Institute, South China Normal University, Guangzhou, 510006, China
- School of Environment, South China Normal University, University Town, Guangzhou, 510006, China
| | - Xin Liu
- Anti-Drug Technology Center of Guangdong Province and National Anti-Drug Laboratory Guangdong Regional Center, Guangdong Provincial Key Laboratory of Psychoactive Substances Monitoring and Safety, Guangzhou, 510230, China
| | - Chu-Shu Huang
- Anti-Drug Technology Center of Guangdong Province and National Anti-Drug Laboratory Guangdong Regional Center, Guangdong Provincial Key Laboratory of Psychoactive Substances Monitoring and Safety, Guangzhou, 510230, China
| | - Guang-Guo Ying
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, SCNU Environmental Research Institute, South China Normal University, Guangzhou, 510006, China.
- School of Environment, South China Normal University, University Town, Guangzhou, 510006, China.
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8
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Wei Y, Li R, Meng Y, Hu T, Zhao J, Gao Y, Bai Q, Li N, Zhao Y. Transport mechanism and pharmacology of the human GlyT1. Cell 2024; 187:1719-1732.e14. [PMID: 38513663 DOI: 10.1016/j.cell.2024.02.026] [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: 10/02/2023] [Revised: 12/09/2023] [Accepted: 02/21/2024] [Indexed: 03/23/2024]
Abstract
The glycine transporter 1 (GlyT1) plays a crucial role in the regulation of both inhibitory and excitatory neurotransmission by removing glycine from the synaptic cleft. Given its close association with glutamate/glycine co-activated NMDA receptors (NMDARs), GlyT1 has emerged as a central target for the treatment of schizophrenia, which is often linked to hypofunctional NMDARs. Here, we report the cryo-EM structures of GlyT1 bound with substrate glycine and drugs ALX-5407, SSR504734, and PF-03463275. These structures, captured at three fundamental states of the transport cycle-outward-facing, occluded, and inward-facing-enable us to illustrate a comprehensive blueprint of the conformational change associated with glycine reuptake. Additionally, we identified three specific pockets accommodating drugs, providing clear insights into the structural basis of their inhibitory mechanism and selectivity. Collectively, these structures offer significant insights into the transport mechanism and recognition of substrate and anti-schizophrenia drugs, thus providing a platform to design small molecules to treat schizophrenia.
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Affiliation(s)
- Yiqing Wei
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Renjie Li
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yufei Meng
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tuo Hu
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Zhao
- Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, Shandong 261000, China
| | - Yiwei Gao
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qinru Bai
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Na Li
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China
| | - Yan Zhao
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
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9
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Tu G, Fu T, Zheng G, Xu B, Gou R, Luo D, Wang P, Xue W. Computational Chemistry in Structure-Based Solute Carrier Transporter Drug Design: Recent Advances and Future Perspectives. J Chem Inf Model 2024; 64:1433-1455. [PMID: 38294194 DOI: 10.1021/acs.jcim.3c01736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Solute carrier transporters (SLCs) are a class of important transmembrane proteins that are involved in the transportation of diverse solute ions and small molecules into cells. There are approximately 450 SLCs within the human body, and more than a quarter of them are emerging as attractive therapeutic targets for multiple complex diseases, e.g., depression, cancer, and diabetes. However, only 44 unique transporters (∼9.8% of the SLC superfamily) with 3D structures and specific binding sites have been reported. To design innovative and effective drugs targeting diverse SLCs, there are a number of obstacles that need to be overcome. However, computational chemistry, including physics-based molecular modeling and machine learning- and deep learning-based artificial intelligence (AI), provides an alternative and complementary way to the classical drug discovery approach. Here, we present a comprehensive overview on recent advances and existing challenges of the computational techniques in structure-based drug design of SLCs from three main aspects: (i) characterizing multiple conformations of the proteins during the functional process of transportation, (ii) identifying druggability sites especially the cryptic allosteric ones on the transporters for substrates and drugs binding, and (iii) discovering diverse small molecules or synthetic protein binders targeting the binding sites. This work is expected to provide guidelines for a deep understanding of the structure and function of the SLC superfamily to facilitate rational design of novel modulators of the transporters with the aid of state-of-the-art computational chemistry technologies including artificial intelligence.
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Affiliation(s)
- Gao Tu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Tingting Fu
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | | | - Binbin Xu
- Chengdu Sintanovo Biotechnology Co., Ltd., Chengdu 610200, China
| | - Rongpei Gou
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Ding Luo
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Panpan Wang
- College of Chemistry and Pharmaceutical Engineering, Huanghuai University, Zhumadian 463000, China
| | - Weiwei Xue
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
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10
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Schmidt SG, Nygaard A, Mindell JA, Loland CJ. Exploring the K + binding site and its coupling to transport in the neurotransmitter:sodium symporter LeuT. eLife 2024; 12:RP87985. [PMID: 38271216 PMCID: PMC10945697 DOI: 10.7554/elife.87985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2024] Open
Abstract
The neurotransmitter:sodium symporters (NSSs) are secondary active transporters that couple the reuptake of substrate to the symport of one or two sodium ions. One bound Na+ (Na1) contributes to the substrate binding, while the other Na+ (Na2) is thought to be involved in the conformational transition of the NSS. Two NSS members, the serotonin transporter (SERT) and the Drosophila dopamine transporter (dDAT), also couple substrate uptake to the antiport of K+ by a largely undefined mechanism. We have previously shown that the bacterial NSS homologue, LeuT, also binds K+, and could therefore serve as a model protein for the exploration of K+ binding in NSS proteins. Here, we characterize the impact of K+ on substrate affinity and transport as well as on LeuT conformational equilibrium states. Both radioligand binding assays and transition metal ion FRET (tmFRET) yielded similar K+ affinities for LeuT. K+ binding was specific and saturable. LeuT reconstituted into proteoliposomes showed that intra-vesicular K+ dose-dependently increased the transport velocity of [3H]alanine, whereas extra-vesicular K+ had no apparent effect. K+ binding induced a LeuT conformation distinct from the Na+- and substrate-bound conformation. Conservative mutations of the Na1 site residues affected the binding of Na+ and K+ to different degrees. The Na1 site mutation N27Q caused a >10-fold decrease in K+ affinity but at the same time a ~3-fold increase in Na+ affinity. Together, the results suggest that K+ binding to LeuT modulates substrate transport and that the K+ affinity and selectivity for LeuT is sensitive to mutations in the Na1 site, pointing toward the Na1 site as a candidate site for facilitating the interaction with K+ in some NSSs.
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Affiliation(s)
- Solveig G Schmidt
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Nygaard
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Joseph A Mindell
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Claus J Loland
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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11
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Addis P, Bali U, Baron F, Campbell A, Harborne S, Jagger L, Milne G, Pearce M, Rosethorne EM, Satchell R, Swift D, Young B, Unitt JF. Key aspects of modern GPCR drug discovery. SLAS DISCOVERY : ADVANCING LIFE SCIENCES R & D 2024; 29:1-22. [PMID: 37625784 DOI: 10.1016/j.slasd.2023.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 08/07/2023] [Accepted: 08/22/2023] [Indexed: 08/27/2023]
Abstract
G-protein-coupled receptors (GPCRs) are the largest and most versatile cell surface receptor family with a broad repertoire of ligands and functions. We've learned an enormous amount about discovering drugs of this receptor class since the first GPCR was cloned and expressed in 1986, such that it's now well-recognized that GPCRs are the most successful target class for approved drugs. Here we take the reader through a GPCR drug discovery journey from target to the clinic, highlighting the key learnings, best practices, challenges, trends and insights on discovering drugs that ultimately modulate GPCR function therapeutically in patients. The future of GPCR drug discovery is inspiring, with more desirable drug mechanisms and new technologies enabling the delivery of better and more successful drugs.
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Affiliation(s)
- Phil Addis
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Utsav Bali
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Frank Baron
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Adrian Campbell
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Steven Harborne
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Liz Jagger
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Gavin Milne
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Martin Pearce
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Elizabeth M Rosethorne
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Rupert Satchell
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Denise Swift
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - Barbara Young
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK
| | - John F Unitt
- Bioscience, Medicinal Chemistry, Pharmacology and Protein Science Departments, Sygnature Discovery Ltd, BioCity, Pennyfoot Street, Nottingham NG1 1GR, UK.
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12
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Clarke A, Farr CV, El-Kasaby A, Szöllősi D, Freissmuth M, Sucic S, Stockner T. Probing binding and occlusion of substrate in the human creatine transporter-1 by computation and mutagenesis. Protein Sci 2024; 33:e4842. [PMID: 38032325 PMCID: PMC10751730 DOI: 10.1002/pro.4842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 11/16/2023] [Accepted: 11/18/2023] [Indexed: 12/01/2023]
Abstract
In chordates, energy buffering is achieved in part through phosphocreatine, which requires cellular uptake of creatine by the membrane-embedded creatine transporter (CRT1/SLC6A8). Mutations in human slc6a8 lead to creatine transporter deficiency syndrome, for which there is only limited treatment. Here, we used a combined homology modeling, molecular dynamics, and experimental approach to generate a structural model of CRT1. Our observations support the following conclusions: contrary to previous proposals, C144, a key residue in the substrate binding site, is not present in a charged state. Similarly, the side chain D458 must be present in a protonated form to maintain the structural integrity of CRT1. Finally, we identified that the interaction chain Y148-creatine-Na+ is essential to the process of occlusion, which occurs via a "hold-and-pull" mechanism. The model should be useful to study the impact of disease-associated point mutations on the folding of CRT1 and identify approaches which correct folding-deficient mutants.
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Affiliation(s)
- Amy Clarke
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Clemens V Farr
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Ali El-Kasaby
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Daniel Szöllősi
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Sonja Sucic
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Thomas Stockner
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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13
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Delpire E, Terker AS, Gagnon KB. Pharmacology of Compounds Targeting Cation-Chloride Cotransporter Physiology. Handb Exp Pharmacol 2024; 283:249-284. [PMID: 37563251 PMCID: PMC10823342 DOI: 10.1007/164_2023_692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Transporters of the solute carrier family 12 (SLC12) carry inorganic cations such as Na+ and/or K+ alongside Cl across the plasma membrane of cells. These tightly coupled, electroneutral, transporters are expressed in almost all tissues/organs in the body where they fulfil many critical functions. The family includes two key transporters participating in salt reabsorption in the kidney: the Na-K-2Cl cotransporter-2 (NKCC2), expressed in the loop of Henle, and the Na-Cl cotransporter (NCC), expressed in the distal convoluted tubule. NCC and NKCC2 are the targets of thiazides and "loop" diuretics, respectively, drugs that are widely used in clinical medicine to treat hypertension and edema. Bumetanide, in addition to its effect as a loop diuretic, has recently received increasing attention as a possible therapeutic agent for neurodevelopmental disorders. This chapter also describes how over the past two decades, the pharmacology of Na+ independent transporters has expanded significantly to provide novel tools for research. This work has indeed led to the identification of compounds that are 100-fold to 1000-fold more potent than furosemide, the first described inhibitor of K-Cl cotransport, and identified compounds that possibly directly stimulate the function of the K-Cl cotransporter. Finally, the recent cryo-electron microscopy revolution has begun providing answers as to where and how pharmacological agents bind to and affect the function of the transporters.
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Affiliation(s)
- Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN, USA.
| | - Andrew S Terker
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Kenneth B Gagnon
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
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14
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Li M, Zhang X, Chen S, Liu H, Zhang YW. Unique Substrate Recognition and Sodium-Substrate Binding Stoichiometry in a Bacterial Serotonin Transporter, TuriSERT. Int J Mol Sci 2023; 24:17112. [PMID: 38069433 PMCID: PMC10707687 DOI: 10.3390/ijms242317112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/27/2023] [Accepted: 12/02/2023] [Indexed: 12/18/2023] Open
Abstract
All resolved high-resolution structures of the transporters in the neurotransmitter sodium symporter (NSS) family revealed that the NSS members share common structural and mechanistic features for substrate and ion binding and transport. However, a recently reported bacterial orthologue of the human serotonin transporter (hSERT), TuriSERT, possesses a structural characteristic specific for amino acid substrate binding but does transport a biogenic amine. The unique structural feature of TuriSERT requires a novel configuration for coordinating its substrate and ions. In the present study, we characterized TuriSERT expressed in Escherichia coli cells with a fluorescent substrate by biochemical, structural, and pharmacological approaches. Substrate transport by TuriSERT requires Na+ but not Cl-. Replacement of Asp262 by asparagine renders TuriSERT Cl--dependent. Substitutions of the corresponding Na1 residues did not alter Na+ dependence on substrate transport, whereas the mutation of a Na2 site residue led to a loss of transport activity, suggesting that Na+ binds only to the Na2 site in TuriSERT. In addition, substitutions of several residues essential for recognizing 5-hydroxytryptamine (5-HT) in hSERT had little effect on 5-HT displacement potency in transport assay for TuriSERT. In contrast, mutations of the residues that are proposed to coordinate with 5-HT in our docking model dramatically reduced 5-HT displacement. Furthermore, our results indicated that all tested antidepressants showed a weak inhibitory effect on TuriSERT. The present study demonstrated the existence of a unique substrate binding site and 1:1 stoichiometry of sodium-substrate binding in TuriSERT, a novel structural finding for the NSS transporters.
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Affiliation(s)
| | | | | | | | - Yuan-Wei Zhang
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China; (M.L.); (X.Z.); (S.C.); (H.L.)
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15
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Alshial EE, Abdulghaney MI, Wadan AHS, Abdellatif MA, Ramadan NE, Suleiman AM, Waheed N, Abdellatif M, Mohammed HS. Mitochondrial dysfunction and neurological disorders: A narrative review and treatment overview. Life Sci 2023; 334:122257. [PMID: 37949207 DOI: 10.1016/j.lfs.2023.122257] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 10/27/2023] [Accepted: 11/07/2023] [Indexed: 11/12/2023]
Abstract
Mitochondria play a vital role in the nervous system, as they are responsible for generating energy in the form of ATP and regulating cellular processes such as calcium (Ca2+) signaling and apoptosis. However, mitochondrial dysfunction can lead to oxidative stress (OS), inflammation, and cell death, which have been implicated in the pathogenesis of various neurological disorders. In this article, we review the main functions of mitochondria in the nervous system and explore the mechanisms related to mitochondrial dysfunction. We discuss the role of mitochondrial dysfunction in the development and progression of some neurological disorders including Parkinson's disease (PD), multiple sclerosis (MS), Alzheimer's disease (AD), depression, and epilepsy. Finally, we provide an overview of various current treatment strategies that target mitochondrial dysfunction, including pharmacological treatments, phototherapy, gene therapy, and mitotherapy. This review emphasizes the importance of understanding the role of mitochondria in the nervous system and highlights the potential for mitochondrial-targeted therapies in the treatment of neurological disorders. Furthermore, it highlights some limitations and challenges encountered by the current therapeutic strategies and puts them in future perspective.
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Affiliation(s)
- Eman E Alshial
- Biochemistry Department, Faculty of Science, Damanhour University, Al Buhayrah, Egypt
| | | | - Al-Hassan Soliman Wadan
- Department of Oral Biology, Faculty of Dentistry, Sinai University, Arish, North Sinai, Egypt
| | | | - Nada E Ramadan
- Department of Biotechnology, Faculty of Science, Tanta University, Gharbia, Egypt
| | | | - Nahla Waheed
- Biochemistry Department, Faculty of Science, Mansoura University, Egypt
| | | | - Haitham S Mohammed
- Biophysics Department, Faculty of Science, Cairo University, Giza, Egypt.
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16
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Stefanski A, Pérez-Palma E, Brünger T, Montanucci L, Gati C, Klöckner C, Johannesen KM, Goodspeed K, Macnee M, Deng AT, Aledo-Serrano Á, Borovikov A, Kava M, Bouman AM, Hajianpour MJ, Pal DK, Engelen M, Hagebeuk EEO, Shinawi M, Heidlebaugh AR, Oetjens K, Hoffman TL, Striano P, Freed AS, Futtrup L, Balslev T, Abulí A, Danvoye L, Lederer D, Balci T, Nouri MN, Butler E, Drewes S, van Engelen K, Howell KB, Khoury J, May P, Trinidad M, Froelich S, Lemke JR, Tiller J, Freed AN, Kang JQ, Wuster A, Møller RS, Lal D. SLC6A1 variant pathogenicity, molecular function and phenotype: a genetic and clinical analysis. Brain 2023; 146:5198-5208. [PMID: 37647852 PMCID: PMC10689929 DOI: 10.1093/brain/awad292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/05/2023] [Accepted: 07/08/2023] [Indexed: 09/01/2023] Open
Abstract
Genetic variants in the SLC6A1 gene can cause a broad phenotypic disease spectrum by altering the protein function. Thus, systematically curated clinically relevant genotype-phenotype associations are needed to understand the disease mechanism and improve therapeutic decision-making. We aggregated genetic and clinical data from 172 individuals with likely pathogenic/pathogenic (lp/p) SLC6A1 variants and functional data for 184 variants (14.1% lp/p). Clinical and functional data were available for a subset of 126 individuals. We explored the potential associations of variant positions on the GAT1 3D structure with variant pathogenicity, altered molecular function and phenotype severity using bioinformatic approaches. The GAT1 transmembrane domains 1, 6 and extracellular loop 4 (EL4) were enriched for patient over population variants. Across functionally tested missense variants (n = 156), the spatial proximity from the ligand was associated with loss-of-function in the GAT1 transporter activity. For variants with complete loss of in vitro GABA uptake, we found a 4.6-fold enrichment in patients having severe disease versus non-severe disease (P = 2.9 × 10-3, 95% confidence interval: 1.5-15.3). In summary, we delineated associations between the 3D structure and variant pathogenicity, variant function and phenotype in SLC6A1-related disorders. This knowledge supports biology-informed variant interpretation and research on GAT1 function. All our data can be interactively explored in the SLC6A1 portal (https://slc6a1-portal.broadinstitute.org/).
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Affiliation(s)
- Arthur Stefanski
- Genomic Medicine Institute and Epilepsy Center, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Eduardo Pérez-Palma
- Universidad del Desarrollo, Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Santiago de Chile 7610658, Chile
| | - Tobias Brünger
- Cologne Center for Genomics (CCG), Medical Faculty of the University of Cologne, University Hospital of Cologne, Cologne 50931, Germany
| | - Ludovica Montanucci
- Genomic Medicine Institute and Epilepsy Center, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Cornelius Gati
- Department of Biological Sciences, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA 90089, USA
| | - Chiara Klöckner
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig 04103, Germany
| | - Katrine M Johannesen
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre, Dianalund 4293, Denmark
- Department of Genetics, University Hospital of Copenhagen, Rigshispitalet, Copenhagen 2100, Denmark
| | - Kimberly Goodspeed
- Children’s Health, Medical Center, Dallas, TX 75235, USA
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marie Macnee
- Cologne Center for Genomics (CCG), Medical Faculty of the University of Cologne, University Hospital of Cologne, Cologne 50931, Germany
| | - Alexander T Deng
- Clinical Genetics, Guys and St Thomas NHS Trust, London SE19RT, UK
| | - Ángel Aledo-Serrano
- Epilepsy Program, Neurology Department, Hospital Ruber Internacional, Madrid 28034, Spain
| | - Artem Borovikov
- Research and Counseling Department, Research Centre for Medical Genetics, Moscow 115478, Russia
| | - Maina Kava
- Department of Neurology and Metabolic Medicine, Perth Children’s Hospital, Perth 6009, Australia
- School of Paediatrics and Child Health, UWA Medical School, University of Western Australia, Perth 6009, Australia
| | - Arjan M Bouman
- Department of Clinical Genetics, Erasmus MC, University Medical Center, Rotterdam 3015GD, The Netherlands
| | - M J Hajianpour
- Department of Pediatrics, Division of Medical Genetics and Genomics, Albany Medical College, Albany Med Health System, Albany, NY 12208, USA
| | - Deb K Pal
- Department of Basic and Clinical Neurosciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College, London SE58AF, UK
- Department of Basic and Clinical Neurosciences, King’s College Hospital, London SE59RS, UK
| | - Marc Engelen
- Department of Pediatric Neurology, Amsterdam Public Health, Amsterdam University Medical Center, Amsterdam 1081HV, The Netherlands
| | - Eveline E O Hagebeuk
- Department of Pediatric Neurology, Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede and Zwolle 2103SW, The Netherlands
| | - Marwan Shinawi
- Division of Genetics and Genomic Medicine, Department of Pediatrics, St.Louis Children’s Hospital, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | - Kathryn Oetjens
- Autism and Developmental Medicine Institute, Geisinger, Danville, PA 17837, USA
| | - Trevor L Hoffman
- Department of Regional Genetics, Anaheim, Southern California Kaiser Permanente Medical Group, CA 92806, USA
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa 16147, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa 16132, Italy
| | - Amanda S Freed
- Department of Clinical Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA 91101, USA
| | - Line Futtrup
- Department of Paediatrics, Regional Hospital of Central Jutland, Viborg 8800, Denmark
| | - Thomas Balslev
- Department of Paediatrics, Regional Hospital of Central Jutland, Viborg 8800, Denmark
- Centre for Educational Development, Aarhus University, Aarhus 8200, Denmark
| | - Anna Abulí
- Department of Clinical and Molecular Genetics and Medicine Genetics Group, VHIR, University Hospital Vall d’Hebron, Barcelona 08035, Spain
| | - Leslie Danvoye
- Department of Neurology, Université catholique de Louvain, Cliniques universitaires Saint-Luc, Brussels 1200, Belgium
| | - Damien Lederer
- Centre for Human Genetics, Institute for Pathology and Genetics, Gosselies 6041, Belgium
| | - Tugce Balci
- Department of Pediatrics, Division of Medical Genetics, Western University, London, ON N6A3K7, Canada
- Medical Genetics Program of Southwestern Ontario, London Health Sciences Centre and Children's Health Research Institute, London, ON N6A5A5, Canada
| | - Maryam Nabavi Nouri
- Department of Paediatrics, Division of Pediatric Neurology, London Health Sciences Centre, London, ON N6A5W9, Canada
| | | | - Sarah Drewes
- Department of Medical Genetics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Kalene van Engelen
- Medical Genetics Program of Southwestern Ontario, London Health Sciences Centre, London, ON N6A5W9, Canada
| | - Katherine B Howell
- Department of Neurology, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
- Department of Pediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
- Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia
| | - Jean Khoury
- Genomic Medicine Institute and Epilepsy Center, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Patrick May
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette 4362, Luxembourg
| | - Marena Trinidad
- Translational Genomics, BioMarin Pharmaceutical Inc., Novato, CA 94949, USA
| | - Steven Froelich
- Translational Genomics, BioMarin Pharmaceutical Inc., Novato, CA 94949, USA
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig 04103, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig 04103, Germany
| | | | | | - Jing-Qiong Kang
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37240, USA
- Neuroscience Graduate Program, Vanderbilt University, Nashville, TN 37235, USA
- Department of Neurology, Vanderbilt Brain Institute, Nashville, TN 37235, USA
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
- Vanderbilt Kennedy Center of Human Development, Nashville, TN 37203, USA
| | - Arthur Wuster
- Translational Genomics, BioMarin Pharmaceutical Inc., Novato, CA 94949, USA
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre, Dianalund 4293, Denmark
- Department of Regional Health Research, University of Southern Denmark, Odense 5000, Denmark
| | - Dennis Lal
- Genomic Medicine Institute and Epilepsy Center, Cleveland Clinic, Cleveland, OH 44195, USA
- Stanley Center of Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Neurology, University of Texas Health Sciences Center at Houston, Houston, TX 77030, USA
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17
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Tu J, Adhikari B, Brennan MA, Bai W, Cheng P, Brennan CS. Shiitake polysaccharides acted as a non-competitive inhibitor to α-glucosidase and inhibited glucose transport of digested starch from Caco-2 cells monolayer. Food Res Int 2023; 173:113268. [PMID: 37803584 DOI: 10.1016/j.foodres.2023.113268] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 07/09/2023] [Accepted: 07/11/2023] [Indexed: 10/08/2023]
Abstract
The inhibition mechanism of shitake mushroom polysaccharides (Lentinula edodes polysaccharides, LEP) against α-glucosidase was studied by enzyme kinetic assay, fluorescence quenching and molecular docking. The effect of LEP on glucose transport of digested starch was investigated via an in vitro digestion/Caco-2 transwell model. LEP exhibited a stronger inhibiting effect (IC50 = 0.66 mg/mL) than acarbose and presented a non-competitive inhibition mechanism. The interaction between LEP and α-glucosidase primarily involved electrostatic interaction and hydrogen bonding. Molecular docking modelling showed that the four structures of LEP were bound to the allosteric tunnel or adjacent pocket of α-glucosidase via electrostatic force and hydrogen bonds. The (1 → 6)-linkages in LEP structures favoured its binding affinity to the α-glucosidase. The α-glucosidase inhibiting activity of LEP was also found to emanate from the reduction in glucose transport of digested starch as deducted from the in vitro digestion/Caco-2 transwell data. The release of glucose from digested starch cooked with LEP was significantly reduced (33.7%) compared to the digested starch without LEP. The findings from the current study suggest that LEP could be a promising ingredient to inhibit α-glucosidase activity as well as control the level of postprandial blood glucose when incorporated into starchy foods.
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Affiliation(s)
- Juncai Tu
- School of Science, RMIT University, GPO Box 2474, Melbourne, VIC 3001, Australia
| | - Benu Adhikari
- School of Science, RMIT University, GPO Box 2474, Melbourne, VIC 3001, Australia.
| | - Margaret Anne Brennan
- School of Science, RMIT University, GPO Box 2474, Melbourne, VIC 3001, Australia; Department of Wine, Food and Molecular Biosciences, Lincoln University, PO Box 84, Lincoln 7647, Christchurch, New Zealand
| | - Weidong Bai
- College of Light Industry and Food Sciences, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Ping Cheng
- College of Light Industry and Food Sciences, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
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18
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Ali I, Silva J, Casillas-Espinosa PM, Braine E, Yamakawa GR, Hudson MR, Brady RD, Major B, Thergarajan P, Haskali MB, Wright DK, Jupp B, Vivash L, Shultz SR, Mychasiuk R, Kwan P, Jones NC, Fukushima K, Sachdev P, Cheng JY, O'Brien TJ. E2730, an uncompetitive γ-aminobutyric acid transporter-1 inhibitor, suppresses epileptic seizures in a rat model of chronic mesial temporal lobe epilepsy. Epilepsia 2023; 64:2806-2817. [PMID: 37539645 DOI: 10.1111/epi.17735] [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: 03/21/2023] [Revised: 08/01/2023] [Accepted: 08/01/2023] [Indexed: 08/05/2023]
Abstract
OBJECTIVE More than one third of mesial temporal lobe epilepsy (MTLE) patients are resistant to current antiseizure medications (ASMs), and half experience mild-to-moderate adverse effects of ASMs. There is therefore a strong need to develop and test novel ASMs. The objective of this work is to evaluate the pharmacokinetics and neurological toxicity of E2730, a novel uncompetitive inhibitor of γ-aminobutyric acid transporter-1, and to test its seizure suppression effects in a rat model of chronic MTLE. METHODS We first examined plasma levels and adverse neurological effects of E2730 in healthy Wistar rats. Adult male rats were implanted with osmotic pumps delivering either 10, 20, or 100 mg/kg/day of E2730 subcutaneously for 1 week. Blood sampling and behavioral assessments were performed at several timepoints. We next examined whether E2730 suppressed seizures in rats with chronic MTLE. These rats were exposed to kainic acid-induced status epilepticus, and 9 weeks later, when chronic epilepsy was established, were assigned to receive one of the three doses of E2730 or vehicle for 1 week in a randomized crossover design. Continuous video-electroencephalographic monitoring was acquired during the treatment period to evaluate epileptic seizures. RESULTS Plasma levels following continuous infusion of E2730 showed a clear dose-related increase in concentration. The drug was well tolerated at all doses, and any sedation or neuromotor impairment was mild and transient, resolving within 48 h of treatment initiation. Remarkably, E2730 treatment in chronically epileptic rats led to seizure suppression in a dose-dependent manner, with 65% of rats becoming seizure-free at the highest dose tested. Mean seizure class did not differ between the treatment groups. SIGNIFICANCE This study shows that continuous subcutaneous infusion of E2730 over 7 days results in a marked, dose-dependent suppression of spontaneous recurrent seizures, with minimal adverse neurological effects, in a rat model of chronic MTLE. E2730 shows strong promise as an effective new ASM to be translated into clinical trials.
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Affiliation(s)
- Idrish Ali
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | - Juliana Silva
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | - Emma Braine
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Glenn R Yamakawa
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Matthew R Hudson
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Rhys D Brady
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Brendan Major
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | | | - Mohammad B Haskali
- Radiopharmaceutical Research Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - David K Wright
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Bianca Jupp
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Lucy Vivash
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Patrick Kwan
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Nigel C Jones
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | | | | | | | - Terence J O'Brien
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
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Yu J, Yao X, Zhang X, Hao J. New insights of metabolite abnormalities in the thalamus of rats with iminodiproprionitrile-induced tic disorders. Front Neurosci 2023; 17:1201294. [PMID: 37841690 PMCID: PMC10570423 DOI: 10.3389/fnins.2023.1201294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 09/15/2023] [Indexed: 10/17/2023] Open
Abstract
Introduction This study aimed to investigate pathological changes in the "Glutamate (Glu)-γ-aminobutyric acid (GABA)" loop and apply widely targeted metabolomic analysis technology to comprehensively explore metabolite abnormalities/ in the thalamus of rats with tic disorders (TD). Methods Wistar rats were randomized into control, TD, and tiapride (Tia) groups. Iminodipropionitrile (IDPN) was used to induce TD in rats. The Tia group was administered tiapride. Neurotransmitter levels in the thalamus of rats in the three groups were measured using UPLC-3Q MS. And, the protein expression levels of Glu decarboxylase (GAD65/67) and GABA transporter protein (GAD-T) were measured using western blotting. The mRNA expression levels of these genes were evaluated using real-time polymerase chain reaction. Lastly, other metabolites in the thalamus were detected by widely targeted metabolomic analysis between TD and Control group rats. Results The Glu level, Glu/GABA ratio, and Asp level in the TD group were significantly higher (all p < 0.001) than those of the Control group, whereas the GABA and Gly levels were lower (p < 0.001 and p = 0.009, respectively). The Tia group exhibited a significant reduction in the Glu level (p = 0.001) compared with the TD group. The protein expression level of GAD67 in TD group was higher (p = 0.009) and the mRNA expression levels of GAD65, GAD67, and GAT-1 were lower (p < 0.05) than those of the Control group. The Tia group did not display any differences in GAD65, GAD67, or GAT-1 expression. Widely targeted metabolomic analysis revealed that 34 substances were abnornal between the TD and Control groups (9 upregulated and 25 downregulated). Neurosteroids (progesterone, corticosterone) exhibited distinct differences. Metabolite analysis using the Kyoto encyclopedia for genes and genomes indicated that the steroid hormone biosynthesis pathway may be involved in TD pathogenesis. Conclusion This study revealed metabolic abnormalities in the thalamus of rats with TD. The interaction between neurotransmitters and neurosteroid biosynthesis represents a new direction for future studies.
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Affiliation(s)
- Jingru Yu
- School of Medicine, Shaoxing University, Shaoxing, China
| | - Xuan Yao
- School of Medicine, Shaoxing University, Shaoxing, China
| | - Xin Zhang
- Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Juanjuan Hao
- School of Medicine, Shaoxing University, Shaoxing, China
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Fukushima K, Higashiyama H, Kazuta Y, Hashimoto K, Watanabe N, Furuya Y, Ito Y, Wu T, Kosasa T, Talos DM, Song Y, Roberts NS, Jensen FE, Hanada T, Ido K. Discovery of E2730, a novel selective uncompetitive GAT1 inhibitor, as a candidate for anti-seizure medication. Epilepsia Open 2023; 8:834-845. [PMID: 37052238 PMCID: PMC10472371 DOI: 10.1002/epi4.12741] [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: 12/12/2022] [Accepted: 04/08/2023] [Indexed: 04/14/2023] Open
Abstract
OBJECTIVE As of 2022, 36 anti-seizure medications (ASMs) have been licensed for the treatment of epilepsy, however, adverse effects (AEs) are commonly reported. Therefore, ASMs with a wide margin between therapeutic effects and AEs are preferred over ASMs that are associated with a narrow margin between efficacy and risk of AEs. E2730 was discovered using in vivo phenotypic screening and characterized as an uncompetitive, yet selective, inhibitor of γ-aminobutyric acid (GABA) transporter 1 (GAT1). Here, we describe the preclinical characteristics of E2730. METHODS Anti-seizure effects of E2730 were evaluated in several animal models of epilepsy: corneal kindling, 6 Hz-44 mA psychomotor seizure, amygdala kindling, Fragile X syndrome, and Dravet syndrome models. Effects of E2730 on motor coordination were assessed in accelerating rotarod tests. The mechanism of action of E2730 was explored by [3 H]E2730 binding assay. The GAT1-selectivity over other GABA transporters was examined by GABA uptake assay of GAT1, GAT2, GAT3, or betaine/GABA transporter 1 (BGT-1) stably expressing HEK293 cells. To further investigate the mechanism for E2730-mediated inhibition of GAT1, in vivo microdialysis and in vitro GABA uptake assays were conducted under conditions of different GABA concentrations. RESULTS E2730 showed anti-seizure effects in the assessed animal models with an approximately >20-fold margin between efficacy and motor incoordination. [3 H]E2730 binding on brain synaptosomal membrane was abolished in GAT1-deficient mice, and E2730 selectively inhibited GAT1-mediated GABA uptake over other GABA transporters. In addition, results of GABA uptake assays showed that E2730-mediated inhibition of GAT1 positively correlated to the level of ambient GABA in vitro. E2730 also increased extracellular GABA concentration in hyperactivated conditions but not under basal levels in vivo. SIGNIFICANCE E2730 is a novel, selective, uncompetitive GAT1 inhibitor, which acts selectively under the condition of increasing synaptic activity, contributing to a wide margin between therapeutic effect and motor incoordination.
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Affiliation(s)
| | | | - Yuji Kazuta
- Deep Human Biology LearningEisai Co., Ltd.TsukubaIbarakiJapan
| | | | - Naoto Watanabe
- Deep Human Biology LearningEisai Co., Ltd.TsukubaIbarakiJapan
| | - Yoshiaki Furuya
- Deep Human Biology LearningEisai Co., Ltd.TsukubaIbarakiJapan
| | - Yoshimasa Ito
- Neurology Business GroupEisai Co., Ltd.TsukubaIbarakiJapan
| | - Ting Wu
- Alzheimer's Disease and Brain HealthEisai Co., Ltd.TsukubaIbarakiJapan
| | - Takashi Kosasa
- Neurology Business GroupEisai Co., Ltd.TsukubaIbarakiJapan
| | - Delia M. Talos
- Department of Neurology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Yeri Song
- Department of Neurology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Nicholas S. Roberts
- Department of Neurology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Frances E. Jensen
- Department of Neurology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Takahisa Hanada
- Deep Human Biology LearningEisai Co., Ltd.TsukubaIbarakiJapan
| | - Katsutoshi Ido
- Neurology Business GroupEisai Co., Ltd.TsukubaIbarakiJapan
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Liang F, Du L, Rao X, Li Y, Long W, Tian J, Zhu X, Zou A, Lu W, Wan B. Effect of electroacupuncture at ST36 on the cerebral metabolic kinetics of rheumatoid arthritis rats. Brain Res Bull 2023; 201:110700. [PMID: 37414302 DOI: 10.1016/j.brainresbull.2023.110700] [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: 02/25/2023] [Revised: 06/27/2023] [Accepted: 07/03/2023] [Indexed: 07/08/2023]
Abstract
Electroacupuncture (EA) has been shown to enhance the recovery of symptoms in rheumatoid arthritis (RA); however, the underlying mechanism remains unclear. Both the pathogenesis of RA and the therapeutic effects of EA are closely associated with the metabolic activity of the brain. In this study, we investigated the effect of EA at the "Zusanli" acupoint (ST36) on a rat model of collagen-induced rheumatoid arthritis (CIA). The results demonstrated that EA effectively alleviated joint swelling, synovial hyperplasia, cartilage erosion, and bone destruction in CIA rats. Additionally, the metabolic kinetics study revealed a significant increase in the 13C enrichment of GABA2 and Glu4 in the midbrain of CIA rats treated with EA. Correlation network analysis showed that changes in Gln4 levels in the hippocampus were strongly associated with the severity of rheumatoid arthritis. Immunofluorescence staining of c-Fos in the midbrain's periaqueductal gray matter (PAG) and hippocampus demonstrated increased c-Fos expression in these regions following EA treatment. These findings suggest that GABAergic and glutamatergic neurons in the midbrain, along with astrocytes in the hippocampus, may play vital roles in the beneficial effects of EA on RA. Furthermore, the PAG and hippocampus brain regions hold potential as critical targets for future RA treatments. Overall, this study provides valuable insights into the specific mechanism of EA in treating RA by elucidating the perspective of cerebral metabolism.
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Affiliation(s)
- Fangyuan Liang
- College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
| | - Lei Du
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xiaoping Rao
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan, China
| | - Ying Li
- College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
| | - Wei Long
- College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
| | - Jiaxuan Tian
- College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
| | - Xuanai Zhu
- College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
| | - Aijia Zou
- College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
| | - Wei Lu
- Clinical College of Chinese Medicine, Hubei University of Chinese Medicine, Wuhan, China.
| | - Bijiang Wan
- College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China; Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan, China.
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Schlessinger A, Zatorski N, Hutchinson K, Colas C. Targeting SLC transporters: small molecules as modulators and therapeutic opportunities. Trends Biochem Sci 2023; 48:801-814. [PMID: 37355450 PMCID: PMC10525040 DOI: 10.1016/j.tibs.2023.05.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/26/2023]
Abstract
Solute carrier (SLCs) transporters mediate the transport of a broad range of solutes across biological membranes. Dysregulation of SLCs has been associated with various pathologies, including metabolic and neurological disorders, as well as cancer and rare diseases. SLCs are therefore emerging as key targets for therapeutic intervention with several recently approved drugs targeting these proteins. Unlocking this large and complex group of proteins is essential to identifying unknown SLC targets and developing next-generation SLC therapeutics. Recent progress in experimental and computational techniques has significantly advanced SLC research, including drug discovery. Here, we review emerging topics in therapeutic discovery of SLCs, focusing on state-of-the-art approaches in structural, chemical, and computational biology, and discuss current challenges in transporter drug discovery.
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Affiliation(s)
- Avner Schlessinger
- Department of Pharmacological Sciences Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Nicole Zatorski
- Department of Pharmacological Sciences Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Keino Hutchinson
- Department of Pharmacological Sciences Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Claire Colas
- University of Vienna, Department of Pharmaceutical Chemistry, Vienna, Austria.
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23
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Zhu A, Huang J, Kong F, Tan J, Lei J, Yuan Y, Yan C. Molecular basis for substrate recognition and transport of human GABA transporter GAT1. Nat Struct Mol Biol 2023:10.1038/s41594-023-00983-z. [PMID: 37400655 DOI: 10.1038/s41594-023-00983-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 03/31/2023] [Indexed: 07/05/2023]
Abstract
γ-Aminobutyric acid (GABA), an important inhibitory neurotransmitter in the central nervous system, is recycled through specific GABA transporters (GATs). GAT1, which is mainly expressed in the presynaptic terminals of axons, is a potential drug target of neurological disorders due to its essential role in GABA transport. Here we report four cryogenic electron microscopy structures of human GAT1, at resolutions of 2.2-3.2 Å. GAT1 in substrate-free form or in complex with the antiepileptic drug tiagabine exhibits an inward-open conformation. In the presence of GABA or nipecotic acid, inward-occluded structures are captured. The GABA-bound structure reveals an interaction network bridged by hydrogen bonds and ion coordination for GABA recognition. The substrate-free structure unwinds the last helical turn of transmembrane helix TM1a to release sodium ions and substrate. Complemented by structure-guided biochemical analyses, our studies reveal detailed mechanism of GABA recognition and transport, and elucidate mode of action of the inhibitors, nipecotic acid and tiagabine.
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Affiliation(s)
- Angqi Zhu
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Junhao Huang
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Fang Kong
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jiaxin Tan
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jianlin Lei
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yafei Yuan
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
| | - Chuangye Yan
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
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24
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Shahsavar A, Wellendorph P. GABA transport cycle: beyond a GAT feeling. Nat Struct Mol Biol 2023:10.1038/s41594-023-01032-5. [PMID: 37400656 DOI: 10.1038/s41594-023-01032-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Affiliation(s)
- Azadeh Shahsavar
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
| | - Petrine Wellendorph
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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25
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Nayak SR, Joseph D, Höfner G, Dakua A, Athreya A, Wanner KT, Kanner BI, Penmatsa A. Cryo-EM structure of GABA transporter 1 reveals substrate recognition and transport mechanism. Nat Struct Mol Biol 2023; 30:1023-1032. [PMID: 37400654 PMCID: PMC10352132 DOI: 10.1038/s41594-023-01011-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 05/04/2023] [Indexed: 07/05/2023]
Abstract
The inhibitory neurotransmitter γ-aminobutyric acid (GABA) is cleared from the synaptic cleft by the sodium- and chloride-coupled GABA transporter GAT1. Inhibition of GAT1 prolongs the GABAergic signaling at the synapse and is a strategy to treat certain forms of epilepsy. In this study, we present the cryo-electron microscopy structure of Rattus norvegicus GABA transporter 1 (rGAT1) at a resolution of 3.1 Å. The structure elucidation was facilitated by epitope transfer of a fragment-antigen binding (Fab) interaction site from the Drosophila dopamine transporter (dDAT) to rGAT1. The structure reveals rGAT1 in a cytosol-facing conformation, with a linear density in the primary binding site that accommodates a molecule of GABA, a displaced ion density proximal to Na site 1 and a bound chloride ion. A unique insertion in TM10 aids the formation of a compact, closed extracellular gate. Besides yielding mechanistic insights into ion and substrate recognition, our study will enable the rational design of specific antiepileptics.
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Affiliation(s)
| | - Deepthi Joseph
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX, USA
| | - Georg Höfner
- Department of Pharmacy, Center for Drug Research, Ludwig Maximilians University of Munich, Munich, Germany
| | - Archishman Dakua
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
- Biophysics Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Arunabh Athreya
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Klaus T Wanner
- Department of Pharmacy, Center for Drug Research, Ludwig Maximilians University of Munich, Munich, Germany
| | - Baruch I Kanner
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University, Hadassah Medical School, Jerusalem, Israel
| | - Aravind Penmatsa
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India.
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Dvorak V, Superti-Furga G. Structural and functional annotation of solute carrier transporters: implication for drug discovery. Expert Opin Drug Discov 2023; 18:1099-1115. [PMID: 37563933 DOI: 10.1080/17460441.2023.2244760] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/01/2023] [Indexed: 08/12/2023]
Abstract
INTRODUCTION Solute carriers (SLCs) represent the largest group of membrane transporters in the human genome. They play a central role in controlling the compartmentalization of metabolism and most of this superfamily is linked to human disease. Despite being in general considered druggable and attractive therapeutic targets, many SLCs remain poorly annotated, both functionally and structurally. AREAS COVERED The aim of this review is to provide an overview of functional and structural parameters of SLCs that play important roles in their druggability. To do this, the authors provide an overview of experimentally solved structures of human SLCs, with emphasis on structures solved in complex with chemical modulators. From the functional annotations, the authors focus on SLC localization and SLC substrate annotations. EXPERT OPINION Recent progress in the structural and functional annotations allows to refine the SLC druggability index. Particularly the increasing number of experimentally solved structures of SLCs provides insights into mode-of-action of a significant number of chemical modulators of SLCs.
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Affiliation(s)
- Vojtech Dvorak
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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Liu J, Ke P, Guo H, Gu J, Liu Y, Tian X, Wang X, Xiao F. Activation of TLR7-mediated autophagy increases epileptic susceptibility via reduced KIF5A-dependent GABA A receptor transport in a murine model. Exp Mol Med 2023; 55:1159-1173. [PMID: 37258573 PMCID: PMC10317981 DOI: 10.1038/s12276-023-01000-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 06/02/2023] Open
Abstract
The pathophysiological mechanisms underlying epileptogenesis are poorly understood but are considered to actively involve an imbalance between excitatory and inhibitory synaptic transmission. Excessive activation of autophagy, a cellular pathway that leads to the removal of proteins, is known to aggravate the disease. Toll-like receptor (TLR) 7 is an innate immune receptor that regulates autophagy in infectious and noninfectious diseases. However, the relationship between TLR7, autophagy, and synaptic transmission during epileptogenesis remains unclear. We found that TLR7 was activated in neurons in the early stage of epileptogenesis. TLR7 knockout significantly suppressed seizure susceptibility and neuronal excitability. Furthermore, activation of TLR7 induced autophagy and decreased the expression of kinesin family member 5 A (KIF5A), which influenced interactions with γ-aminobutyric acid type A receptor (GABAAR)-associated protein and GABAARβ2/3, thus producing abnormal GABAAR-mediated postsynaptic transmission. Our results indicated that TLR7 is an important factor in regulating epileptogenesis, suggesting a possible therapeutic target for epilepsy.
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Affiliation(s)
- Jing Liu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, 400016, China
- Department of Neurology, Chongqing University Three Gorges Hospital, 165 Xincheng Road, Chongqing, 404100, China
| | - Pingyang Ke
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, 400016, China
| | - Haokun Guo
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, 400016, China
| | - Juan Gu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, 400016, China
| | - Yan Liu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, 400016, China
| | - Xin Tian
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, 400016, China
| | - Xuefeng Wang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, 400016, China.
| | - Fei Xiao
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, 400016, China.
- Institute for Brain Science and Disease of Chongqing Medical University, Chongqing, 400016, China.
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28
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Zhang B, Zhang P, L T, Cao Y, Chen T, Chen C, Zhang Z, Zhong Q. P2X7 Receptor in microglia contributes to propofol-induced unconsciousness by regulating synaptic plasticity in mice. Neuroscience 2023:S0306-4522(23)00223-3. [PMID: 37211083 DOI: 10.1016/j.neuroscience.2023.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 04/16/2023] [Accepted: 05/14/2023] [Indexed: 05/23/2023]
Abstract
Propofol infusion is processed through the wake-sleep cycle in neural connections, and the ionotropic purine type 2X7 receptor (P2X7R) is a nonspecific cation channel implicated in sleep regulation and synaptic plasticity through its regulation of electric activity in the brain. Here, we explored the potential roles of P2X7R of microglia in propofol-induced unconsciousness. Propofol induced loss of the righting reflex in male C57BL/6 wild-type mice and increased spectral power of the slow wave and delta wave of the medial prefrontal cortex (mPFC), all of which were reversed with P2X7R antagonist A-740003 and strengthened with P2X7R agonist Bz-ATP. Propofol increased the P2X7R expression level and P2X7R immunoreactivity with microglia in the mPFC, induced mild synaptic injury and increased GABA release in the mPFC, and these changes were less severe when treated with A-740003 and were more obvious when treated with Bz-ATP. Electrophysiological approaches showed that propofol induced a decreased frequency of sEPSCs and an increased frequency of sIPSCs, A-740003 decrease frequency of sEPSCs and sIPSCs and Bz-ATP increase frequency of sEPSCs and sIPSCs under propofol anesthesia. These findings indicated that P2X7R in microglia regulates synaptic plasticity and may contribute to propofol-mediated unconsciousness.
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Affiliation(s)
- Bo Zhang
- Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China, 430022
| | - Panpan Zhang
- Department of Anesthesiology, Zhongnan Hospital, Wuhan University, East Lake Road, Wuhan, Hubei, China, 430071; Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China, 430022
| | - Tingting L
- Department of Anesthesiology, Zhongnan Hospital, Wuhan University, East Lake Road, Wuhan, Hubei, China, 430071
| | - Yue Cao
- Department of Anesthesiology, Zhongnan Hospital, Wuhan University, East Lake Road, Wuhan, Hubei, China, 430071
| | - Ting Chen
- Department of Anesthesiology, Zhongnan Hospital, Wuhan University, East Lake Road, Wuhan, Hubei, China, 430071
| | - Chang Chen
- Department of Anesthesiology, Zhongnan Hospital, Wuhan University, East Lake Road, Wuhan, Hubei, China, 430071
| | - Zongze Zhang
- Department of Anesthesiology, Zhongnan Hospital, Wuhan University, East Lake Road, Wuhan, Hubei, China, 430071.
| | - Qi Zhong
- Department of Anesthesiology, Zhongnan Hospital, Wuhan University, East Lake Road, Wuhan, Hubei, China, 430071.
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29
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Fogarty MJ. Inhibitory Synaptic Influences on Developmental Motor Disorders. Int J Mol Sci 2023; 24:ijms24086962. [PMID: 37108127 PMCID: PMC10138861 DOI: 10.3390/ijms24086962] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
During development, GABA and glycine play major trophic and synaptic roles in the establishment of the neuromotor system. In this review, we summarise the formation, function and maturation of GABAergic and glycinergic synapses within neuromotor circuits during development. We take special care to discuss the differences in limb and respiratory neuromotor control. We then investigate the influences that GABAergic and glycinergic neurotransmission has on two major developmental neuromotor disorders: Rett syndrome and spastic cerebral palsy. We present these two syndromes in order to contrast the approaches to disease mechanism and therapy. While both conditions have motor dysfunctions at their core, one condition Rett syndrome, despite having myriad symptoms, has scientists focused on the breathing abnormalities and their alleviation-to great clinical advances. By contrast, cerebral palsy remains a scientific quagmire or poor definitions, no widely adopted model and a lack of therapeutic focus. We conclude that the sheer abundance of diversity of inhibitory neurotransmitter targets should provide hope for intractable conditions, particularly those that exhibit broad spectra of dysfunction-such as spastic cerebral palsy and Rett syndrome.
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Affiliation(s)
- Matthew J Fogarty
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN 55902, USA
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30
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Piniella D, Zafra F. Functional crosstalk of the glycine transporter GlyT1 and NMDA receptors. Neuropharmacology 2023; 232:109514. [PMID: 37003571 DOI: 10.1016/j.neuropharm.2023.109514] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/10/2023] [Accepted: 03/20/2023] [Indexed: 04/03/2023]
Abstract
NMDA-type glutamate receptors (NMDARs) constitute one of the main glutamate (Glu) targets in the central nervous system and are involved in synaptic plasticity, which is the molecular substrate of learning and memory. Hypofunction of NMDARs has been associated with schizophrenia, while overstimulation causes neuronal death in neurodegenerative diseases or in stroke. The function of NMDARs requires coincidental binding of Glu along with other cellular signals such as neuronal depolarization, and the presence of other endogenous ligands that modulate their activity by allosterism. Among these allosteric modulators are zinc, protons and Gly, which is an obligatory co-agonist. These characteristics differentiate NMDARs from other receptors, and their structural bases have begun to be established in recent years. In this review we focus on the crosstalk between Glu and glycine (Gly), whose concentration in the NMDAR microenvironment is maintained by various Gly transporters that remove or release it into the medium in a regulated manner. The GlyT1 transporter is particularly involved in this task, and has become a target of great interest for the treatment of schizophrenia since its inhibition leads to an increase in synaptic Gly levels that enhances the activity of NMDARs. However, the only drug that has completed phase III clinical trials did not yield the expected results. Notwithstanding, there are additional drugs that continue to be investigated, and it is hoped that knowledge gained from the recently published 3D structure of GlyT1 may allow the rational design of more effective new drugs.
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Affiliation(s)
- Dolores Piniella
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Institute of Health Carlos III (ISCIII), Spain
| | - Francisco Zafra
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Institute of Health Carlos III (ISCIII), Spain.
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31
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Stary D, Bajda M. Taurine and Creatine Transporters as Potential Drug Targets in Cancer Therapy. Int J Mol Sci 2023; 24:ijms24043788. [PMID: 36835201 PMCID: PMC9964810 DOI: 10.3390/ijms24043788] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
Cancer cells are characterized by uncontrolled growth, proliferation, and impaired apoptosis. Tumour progression could be related to poor prognosis and due to this fact, researchers have been working on novel therapeutic strategies and antineoplastic agents. It is known that altered expression and function of solute carrier proteins from the SLC6 family could be associated with severe diseases, including cancers. These proteins were noticed to play important physiological roles through transferring nutrient amino acids, osmolytes, neurotransmitters, and ions, and many of them are necessary for survival of the cells. Herein, we present the potential role of taurine (SLC6A6) and creatine (SLC6A8) transporters in cancer development as well as therapeutic potential of their inhibitors. Experimental data indicate that overexpression of analyzed proteins could be connected with colon or breast cancers, which are the most common types of cancers. The pool of known inhibitors of these transporters is limited; however, one ligand of SLC6A8 protein is currently tested in the first phase of clinical trials. Therefore, we also highlight structural aspects useful for ligand development. In this review, we discuss SLC6A6 and SLC6A8 transporters as potential biological targets for anticancer agents.
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Affiliation(s)
- Dorota Stary
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688 Cracow, Poland
- Doctoral School of Medical and Health Sciences, Jagiellonian University Medical College, św. Łazarza 16 St., 31-530 Cracow, Poland
| | - Marek Bajda
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688 Cracow, Poland
- Correspondence:
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32
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Kasture AS, Fischer FP, Kunert L, Burger ML, Burgstaller AC, El-Kasaby A, Hummel T, Sucic S. Drosophila melanogaster as a model for unraveling unique molecular features of epilepsy elicited by human GABA transporter 1 variants. Front Neurosci 2023; 16:1074427. [PMID: 36741049 PMCID: PMC9893286 DOI: 10.3389/fnins.2022.1074427] [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] [Received: 10/19/2022] [Accepted: 12/21/2022] [Indexed: 01/20/2023] Open
Abstract
Mutations in the human γ-aminobutyric acid (GABA) transporter 1 (hGAT-1) can instigate myoclonic-atonic and other generalized epilepsies in the afflicted individuals. We systematically examined fifteen hGAT-1 disease variants, all of which dramatically reduced or completely abolished GABA uptake activity. Many of these loss-of-function variants were absent from their regular site of action at the cell surface, due to protein misfolding and/or impaired trafficking machinery (as verified by confocal microscopy and de-glycosylation experiments). A modest fraction of the mutants displayed correct targeting to the plasma membrane, but nonetheless rendered the mutated proteins devoid of GABA transport, possibly due to structural alterations in the GABA binding site/translocation pathway. We here focused on a folding-deficient A288V variant. In flies, A288V reiterated its impeded expression pattern, closely mimicking the ER-retention demonstrated in transfected HEK293 cells. Functionally, A288V presented a temperature-sensitive seizure phenotype in fruit flies. We employed diverse small molecules to restore the expression and activity of folding-deficient hGAT-1 epilepsy variants, in vitro (in HEK293 cells) and in vivo (in flies). We identified three compounds (chemical and pharmacological chaperones) conferring moderate rescue capacity for several variants. Our data grant crucial new insights into: (i) the molecular basis of epilepsy in patients harboring hGAT-1 mutations, and (ii) a proof-of-principle that protein folding deficits in disease-associated hGAT-1 variants can be corrected using the pharmacochaperoning approach. Such innovative pharmaco-therapeutic prospects inspire the rational design of novel drugs for alleviating the clinical symptoms triggered by the numerous emerging pathogenic mutations in hGAT-1.
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Affiliation(s)
- Ameya S. Kasture
- Institute of Pharmacology, Medical University of Vienna, Vienna, Austria,Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria
| | - Florian P. Fischer
- Institute of Pharmacology, Medical University of Vienna, Vienna, Austria,Department of Epileptology and Neurology, University of Aachen, Aachen, Germany
| | - Lisa Kunert
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria
| | - Melanie L. Burger
- Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | | | - Ali El-Kasaby
- Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Thomas Hummel
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria
| | - Sonja Sucic
- Institute of Pharmacology, Medical University of Vienna, Vienna, Austria,*Correspondence: Sonja Sucic,
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33
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Experimental and Bioinformatic Insights into the Effects of Epileptogenic Variants on the Function and Trafficking of the GABA Transporter GAT-1. Int J Mol Sci 2023; 24:ijms24020955. [PMID: 36674476 PMCID: PMC9862756 DOI: 10.3390/ijms24020955] [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] [Received: 11/29/2022] [Revised: 12/27/2022] [Accepted: 12/31/2022] [Indexed: 01/06/2023] Open
Abstract
In this article, we identified a novel epileptogenic variant (G307R) of the gene SLC6A1, which encodes the GABA transporter GAT-1. Our main goal was to investigate the pathogenic mechanisms of this variant, located near the neurotransmitter permeation pathway, and compare it with other variants located either in the permeation pathway or close to the lipid bilayer. The mutants G307R and A334P, close to the gates of the transporter, could be glycosylated with variable efficiency and reached the membrane, albeit inactive. Mutants located in the center of the permeation pathway (G297R) or close to the lipid bilayer (A128V, G550R) were retained in the endoplasmic reticulum. Applying an Elastic Network Model, to these and to other previously characterized variants, we found that G307R and A334P significantly perturb the structure and dynamics of the intracellular gate, which can explain their reduced activity, while for A228V and G362R, the reduced translocation to the membrane quantitatively accounts for the reduced activity. The addition of a chemical chaperone (4-phenylbutyric acid, PBA), which improves protein folding, increased the activity of GAT-1WT, as well as most of the assayed variants, including G307R, suggesting that PBA might also assist the conformational changes occurring during the alternative access transport cycle.
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34
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Li RQ, Zhao XH, Zhu Q, Liu T, Hondermarck H, Thorne RF, Zhang XD, Gao JN. Exploring neurotransmitters and their receptors for breast cancer prevention and treatment. Theranostics 2023; 13:1109-1129. [PMID: 36793869 PMCID: PMC9925324 DOI: 10.7150/thno.81403] [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] [Received: 11/30/2022] [Accepted: 01/18/2023] [Indexed: 02/04/2023] Open
Abstract
While psychological factors have long been linked to breast cancer pathogenesis and outcomes, accumulating evidence is revealing how the nervous system contributes to breast cancer development, progression, and treatment resistance. Central to the psychological-neurological nexus are interactions between neurotransmitters and their receptors expressed on breast cancer cells and other types of cells in the tumor microenvironment, which activate various intracellular signaling pathways. Importantly, the manipulation of these interactions is emerging as a potential avenue for breast cancer prevention and treatment. However, an important caveat is that the same neurotransmitter can exert multiple and sometimes opposing effects. In addition, certain neurotransmitters can be produced and secreted by non-neuronal cells including breast cancer cells that similarly activate intracellular signaling upon binding to their receptors. In this review we dissect the evidence for the emerging paradigm linking neurotransmitters and their receptors with breast cancer. Foremost, we explore the intricacies of such neurotransmitter-receptor interactions, including those that impinge on other cellular components of the tumor microenvironment, such as endothelial cells and immune cells. Moreover, we discuss findings where clinical agents used to treat neurological and/or psychological disorders have exhibited preventive/therapeutic effects against breast cancer in either associative or pre-clinical studies. Further, we elaborate on the current progress to identify druggable components of the psychological-neurological nexus that can be exploited for the prevention and treatment of breast cancer as well as other tumor types. We also provide our perspectives regarding future challenges in this field where multidisciplinary cooperation is a paramount requirement.
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Affiliation(s)
- Ruo Qi Li
- General Surgery Department, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, China.,These authors contributed equally to this work
| | - Xiao Hong Zhao
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, New South Wales, Australia.,These authors contributed equally to this work
| | - Qin Zhu
- General Surgery Department, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, China
| | - Tao Liu
- Children's Cancer Institute Australia for Medical Research, The University of New South Wales, Sydney, NSW, Australia
| | - Hubert Hondermarck
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, New South Wales, Australia
| | - Rick F Thorne
- Translational Research Institute, Henan Provincial and Zhengzhou City Key laboratory of Non-coding RNA and Cancer Metabolism, Henan International Joint Laboratory of Non-coding RNA and Metabolism in Cancer, Zhengzhou University People's Hospital and Henan Provincial People's Hospital, Academy of Medical Sciences, Zhengzhou University, Henan, China
| | - Xu Dong Zhang
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, New South Wales, Australia.,Translational Research Institute, Henan Provincial and Zhengzhou City Key laboratory of Non-coding RNA and Cancer Metabolism, Henan International Joint Laboratory of Non-coding RNA and Metabolism in Cancer, Zhengzhou University People's Hospital and Henan Provincial People's Hospital, Academy of Medical Sciences, Zhengzhou University, Henan, China
| | - Jin Nan Gao
- General Surgery Department, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, China
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35
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Kanner BI, Dayan-Alon O. GABA transport goes structural. Trends Pharmacol Sci 2023; 44:4-6. [PMID: 35985875 DOI: 10.1016/j.tips.2022.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/29/2022] [Accepted: 08/03/2022] [Indexed: 12/27/2022]
Abstract
The γ-aminobutyric acid transporter 1 (GAT1) is a transporter which clears the inhibitory neurotransmitter γ-aminobutyric acid (GABA) from the synaptic cleft. The paper by Motiwala et al. documents a structure of GAT1 in complex with the antiepileptic drug tiagabine. This study will enable structure-based docking of large chemical libraries for the discovery of novel antiepileptics.
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Affiliation(s)
- Baruch I Kanner
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University, Hadassah Medical School, Jerusalem 91120, Israel.
| | - Oshrat Dayan-Alon
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University, Hadassah Medical School, Jerusalem 91120, Israel
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36
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Bhatt M, Gauthier-Manuel L, Lazzarin E, Zerlotti R, Ziegler C, Bazzone A, Stockner T, Bossi E. A comparative review on the well-studied GAT1 and the understudied BGT-1 in the brain. Front Physiol 2023; 14:1145973. [PMID: 37123280 PMCID: PMC10137170 DOI: 10.3389/fphys.2023.1145973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/30/2023] [Indexed: 05/02/2023] Open
Abstract
γ-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system (CNS). Its homeostasis is maintained by neuronal and glial GABA transporters (GATs). The four GATs identified in humans are GAT1 (SLC6A1), GAT2 (SLC6A13), GAT3 (SLC6A11), and betaine/GABA transporter-1 BGT-1 (SLC6A12) which are all members of the solute carrier 6 (SLC6) family of sodium-dependent transporters. While GAT1 has been investigated extensively, the other GABA transporters are less studied and their role in CNS is not clearly defined. Altered GABAergic neurotransmission is involved in different diseases, but the importance of the different transporters remained understudied and limits drug targeting. In this review, the well-studied GABA transporter GAT1 is compared with the less-studied BGT-1 with the aim to leverage the knowledge on GAT1 to shed new light on the open questions concerning BGT-1. The most recent knowledge on transporter structure, functions, expression, and localization is discussed along with their specific role as drug targets for neurological and neurodegenerative disorders. We review and discuss data on the binding sites for Na+, Cl-, substrates, and inhibitors by building on the recent cryo-EM structure of GAT1 to highlight specific molecular determinants of transporter functions. The role of the two proteins in GABA homeostasis is investigated by looking at the transport coupling mechanism, as well as structural and kinetic transport models. Furthermore, we review information on selective inhibitors together with the pharmacophore hypothesis of transporter substrates.
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Affiliation(s)
- Manan Bhatt
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
- Centre for Neuroscience—University of Insubria, Varese, Italy
| | - Laure Gauthier-Manuel
- Department of Biophysics II/Structural Biology, University of Regensburg, Regensburg, Germany
| | - Erika Lazzarin
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Waehringerstr, Vienna
| | - Rocco Zerlotti
- Department of Biophysics II/Structural Biology, University of Regensburg, Regensburg, Germany
- Nanion Technologies GmbH, Munich, Germany
| | - Christine Ziegler
- Department of Biophysics II/Structural Biology, University of Regensburg, Regensburg, Germany
| | | | - Thomas Stockner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Waehringerstr, Vienna
- *Correspondence: Thomas Stockner, ; Elena Bossi,
| | - Elena Bossi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
- Centre for Neuroscience—University of Insubria, Varese, Italy
- *Correspondence: Thomas Stockner, ; Elena Bossi,
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37
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Anderson CMH, Edwards N, Watson AK, Althaus M, Thwaites DT. Reshaping the Binding Pocket of the Neurotransmitter:Solute Symporter (NSS) Family Transporter SLC6A14 (ATB 0,+) Selectively Reduces Access for Cationic Amino Acids and Derivatives. Biomolecules 2022; 12:biom12101404. [PMID: 36291613 PMCID: PMC9599917 DOI: 10.3390/biom12101404] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 09/25/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022] Open
Abstract
SLC6A14 (ATB0,+) is unique among SLC proteins in its ability to transport 18 of the 20 proteinogenic (dipolar and cationic) amino acids and naturally occurring and synthetic analogues (including anti-viral prodrugs and nitric oxide synthase (NOS) inhibitors). SLC6A14 mediates amino acid uptake in multiple cell types where increased expression is associated with pathophysiological conditions including some cancers. Here, we investigated how a key position within the core LeuT-fold structure of SLC6A14 influences substrate specificity. Homology modelling and sequence analysis identified the transmembrane domain 3 residue V128 as equivalent to a position known to influence substrate specificity in distantly related SLC36 and SLC38 amino acid transporters. SLC6A14, with and without V128 mutations, was heterologously expressed and function determined by radiotracer solute uptake and electrophysiological measurement of transporter-associated current. Substituting the amino acid residue occupying the SLC6A14 128 position modified the binding pocket environment and selectively disrupted transport of cationic (but not dipolar) amino acids and related NOS inhibitors. By understanding the molecular basis of amino acid transporter substrate specificity we can improve knowledge of how this multi-functional transporter can be targeted and how the LeuT-fold facilitates such diversity in function among the SLC6 family and other SLC amino acid transporters.
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Affiliation(s)
- Catriona M. H. Anderson
- School of Natural & Environmental Sciences, Faculty of Science, Engineering & Agriculture, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
- Correspondence: (C.M.H.A.); (D.T.T.)
| | - Noel Edwards
- Biosciences Institute, Faculty of Medical Sciences, Framlington Place, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Andrew K. Watson
- Biosciences Institute, Faculty of Medical Sciences, Framlington Place, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Mike Althaus
- School of Natural & Environmental Sciences, Faculty of Science, Engineering & Agriculture, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
- Department of Natural Sciences & Institute for Functional Gene Analytics, Bonn-Rhein-Sieg University of Applied Sciences, 53359 Rheinbach, Germany
| | - David T. Thwaites
- Biosciences Institute, Faculty of Medical Sciences, Framlington Place, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Correspondence: (C.M.H.A.); (D.T.T.)
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38
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Del Alamo D, Meiler J, Mchaourab HS. Principles of Alternating Access in LeuT-fold Transporters: Commonalities and Divergences. J Mol Biol 2022; 434:167746. [PMID: 35843285 DOI: 10.1016/j.jmb.2022.167746] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/08/2022] [Accepted: 07/09/2022] [Indexed: 11/15/2022]
Abstract
Found in all domains of life, transporters belonging to the LeuT-fold class mediate the import and exchange of hydrophilic and charged compounds such as amino acids, metals, and sugar molecules. Nearly two decades of investigations on the eponymous bacterial transporter LeuT have yielded a library of high-resolution snapshots of its conformational cycle linked by solution-state experimental data obtained from multiple techniques. In parallel, its topology has been observed in symporters and antiporters characterized by a spectrum of substrate specificities and coupled to gradients of distinct ions. Here we review and compare mechanistic models of transport for LeuT, its well-studied homologs, as well as functionally distant members of the fold, emphasizing the commonalities and divergences in alternating access and the corresponding energy landscapes. Our integrated summary illustrates how fold conservation, a hallmark of the LeuT fold, coincides with divergent choreographies of alternating access that nevertheless capitalize on recurrent structural motifs. In addition, it highlights the knowledge gap that hinders the leveraging of the current body of research into detailed mechanisms of transport for this important class of membrane proteins.
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Affiliation(s)
- Diego Del Alamo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA; Department of Chemistry, Vanderbilt University, Nashville, TN, USA. https://twitter.com/DdelAlamo
| | - Jens Meiler
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA; Institute for Drug Discovery, Leipzig University, Leipzig, DE, USA. https://twitter.com/MeilerLab
| | - Hassane S Mchaourab
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
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