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Sočan V, Dolinar K, Kržan M. Kinetic Properties and Pharmacological Modulation of High- and Low-Affinity Dopamine Transport in Striatal Astrocytes of Adult Rats. Int J Mol Sci 2024; 25:5135. [PMID: 38791173 PMCID: PMC11121484 DOI: 10.3390/ijms25105135] [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: 04/03/2024] [Revised: 05/06/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
Astrocytes actively participate in neurotransmitter homeostasis by bidirectional communication with neuronal cells, a concept named the tripartite synapse, yet their role in dopamine (DA) homeostasis remains understudied. In the present study, we investigated the kinetic and molecular mechanisms of DA transport in cultured striatal astrocytes of adult rats. Kinetic uptake experiments were performed using radiolabeled [3H]-DA, whereas mRNA expression of the dopamine, norepinephrine, organic cation and plasma membrane monoamine transporters (DAT, NET, OCTs and PMAT) and DA receptors D1 and D2 was determined by qPCR. Additionally, astrocyte cultures were subjected to a 24 h treatment with the DA receptor agonist apomorphine, the DA receptor antagonist haloperidol and the DA precursor L-DOPA. [3H]-DA uptake exhibited temperature, concentration and sodium dependence, with potent inhibition by desipramine, nortriptyline and decynium-22, suggesting the involvement of multiple transporters. qPCR revealed prominent mRNA expression of the NET, the PMAT and OCT1, alongside lower levels of mRNA for OCT2, OCT3 and the DAT. Notably, apomorphine significantly altered NET, PMAT and D1 mRNA expression, while haloperidol and L-DOPA had a modest impact. Our findings demonstrate that striatal astrocytes aid in DA clearance by multiple transporters, which are influenced by dopaminergic drugs. Our study enhances the understanding of regional DA uptake, paving the way for targeted therapeutic interventions in dopaminergic disorders.
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Affiliation(s)
- Vesna Sočan
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | - Klemen Dolinar
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | - Mojca Kržan
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
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Sočan V, Dolinar K, Kržan M. Transporters involved in adult rat cortical astrocyte dopamine uptake: Kinetics, expression and pharmacological modulation. Eur J Neurosci 2024; 59:1296-1310. [PMID: 38054361 DOI: 10.1111/ejn.16202] [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: 09/01/2023] [Revised: 11/03/2023] [Accepted: 11/10/2023] [Indexed: 12/07/2023]
Abstract
Astrocytes, glial cells in the central nervous system, perform a multitude of homeostatic functions and are in constant bidirectional communication with neuronal cells, a concept named the tripartite synapse; however, their role in the dopamine homeostasis remains unexplored. The aim of this study was to clarify the pharmacological and molecular characteristics of dopamine transport in cultured cortical astrocytes of adult rats. In addition, we were interested in the expression of mRNA of dopamine transporters as well as dopamine receptors D1 and D2 and in the effect of dopaminergic drugs on the expression of these transporters and receptors. We have found that astrocytes possess both Na+-dependent and Na+-independent transporters. Uptake of radiolabelled dopamine was time-, temperature- and concentration-dependent and was inhibited by decynium-22, a plasma membrane monoamine transporter inhibitor, tricyclic antidepressants desipramine and nortriptyline, both inhibitors of the norepinephrine transporter. Results of transporter mRNA expression indicate that the main transporters involved in cortical astrocyte dopamine uptake are the norepinephrine transporter and plasma membrane monoamine transporter. Both dopamine receptor subtypes were identified in cortical astrocyte cultures. Twenty-four-hour treatment of astrocyte cultures with apomorphine, a D1/D2 agonist, induced upregulation of D1 receptor, norepinephrine transporter and plasma membrane monoamine transporter, whereas the latter was downregulated by haloperidol and L-DOPA. Astrocytes take up dopamine by multiple transporters and express dopamine receptors, which are sensitive to dopaminergic drugs. The findings of this study could open a promising area of research for the fine-tuning of existing therapeutic strategies.
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Affiliation(s)
- Vesna Sočan
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Klemen Dolinar
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Mojca Kržan
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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Sočan V, Dolinar K, Kržan M. Cortical and Striatal Astrocytes of Neonatal Rats Display Distinct Molecular and Pharmacological Characteristics of Dopamine Uptake. Int J Mol Sci 2024; 25:911. [PMID: 38255983 PMCID: PMC10815805 DOI: 10.3390/ijms25020911] [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: 12/12/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Astrocytes are crucial in the regulation of neurotransmitter homeostasis, and while their involvement in the dopamine (DA) tripartite synapse is acknowledged, it necessitates a more comprehensive investigation. In the present study, experiments were conducted on primary astrocyte cultures from the striatum and cortex of neonatal rats. The pharmacological intricacies of DA uptake, including dependence on time, temperature, and concentration, were investigated using radiolabelled [3H]-DA. The mRNA expression of transporters DAT, NET, PMAT, and OCTs was evaluated by qPCR. Notably, astrocytes from both brain regions exhibited prominent mRNA expression of NET and PMAT, with comparatively lower expression of DAT and OCTs. The inhibition of DA uptake by the DAT inhibitor, GBR12909, and NET inhibitors, desipramine and nortriptyline, impeded DA uptake in striatal astrocytes more than in cortical astrocytes. The mRNA expression of NET and PMAT was significantly upregulated in cortical astrocytes in response to the DA receptor agonist apomorphine, while only the mRNA expression of NET exhibited changes in striatal astrocytes. Haloperidol, a DA receptor antagonist, and L-DOPA, a DA precursor, did not induce significant alterations in transporter mRNA expression. These findings underscore the intricate and region-specific mechanisms governing DA uptake in astrocytes, emphasizing the need for continued exploration to unravel the nuanced dynamics of astrocytic involvement in the DA tripartite synapse.
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Affiliation(s)
- Vesna Sočan
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | - Klemen Dolinar
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | - Mojca Kržan
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
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Vieira LS, Zhang Y, López Quiñones AJ, Hu T, Singh DK, Stevens J, Prasad B, Park JR, Wang J. The Plasma Membrane Monoamine Transporter is Highly Expressed in Neuroblastoma and Functions as an mIBG Transporter. J Pharmacol Exp Ther 2023; 387:239-248. [PMID: 37541765 PMCID: PMC10658915 DOI: 10.1124/jpet.123.001672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/27/2023] [Accepted: 07/06/2023] [Indexed: 08/06/2023] Open
Abstract
Neuroblastoma (NB) is a pediatric cancer with low survival rates in high-risk patients. 131I-mIBG has emerged as a promising therapy for high-risk NB and kills tumor cells by radiation. Consequently, 131I-mIBG tumor uptake and retention are major determinants for its therapeutic efficacy. mIBG enters NB cells through the norepinephrine transporter (NET), and accumulates in mitochondria through unknown mechanisms. Here we evaluated the expression of monoamine and organic cation transporters in high-risk NB tumors and explored their relationship with MYCN amplification and patient survival. We found that NB mainly expresses NET, the plasma membrane monoamine transporter (PMAT), and the vesicular membrane monoamine transporter 1/2 (VMAT1/2), and that the expression of these transporters is significantly reduced in MYCN-amplified tumor samples. PMAT expression is the highest and correlates with overall survival in high-risk NB patients without MYCN amplification. Immunostaining showed that PMAT resides intracellularly in NB cells and co-localizes with mitochondria. Using cells expressing PMAT, mIBG was identified as a PMAT substrate. In mitochondria isolated from NB cell lines, mIBG uptake was reduced by ∼50% by a PMAT inhibitor. Together, our data suggest that PMAT is a previously unrecognized transporter highly expressed in NB and could impact intracellular transport and therapeutic response to 131I-mIBG. SIGNIFICANCE STATEMENT: This study identified that plasma membrane monoamine transporter (PMAT) is a novel transporter highly expressed in neuroblastoma and its expression level is associated with overall survival rate in high-risk patients without MYCN amplification. PMAT is expressed intracellularly in neuroblastoma cells, transports meta-iodobenzylguanidine (mIBG) and thus could impact tumor retention and response to 131I-mIBG therapy. These findings have important clinical implications as PMAT could represent a novel molecular marker to help inform disease prognosis and predict response to 131I-mIBG therapy.
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Affiliation(s)
- Letícia Salvador Vieira
- Department of Pharmaceutics, University of Washington, Seattle, Washington (L.S.V., Y.Z., A.J.L.Q., T.H., J.W.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (D.K.S., B.P.); and Seattle Children's Hospital, Seattle, Washington (J.S., J.R.P.)
| | - Yuchen Zhang
- Department of Pharmaceutics, University of Washington, Seattle, Washington (L.S.V., Y.Z., A.J.L.Q., T.H., J.W.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (D.K.S., B.P.); and Seattle Children's Hospital, Seattle, Washington (J.S., J.R.P.)
| | - Antonio J López Quiñones
- Department of Pharmaceutics, University of Washington, Seattle, Washington (L.S.V., Y.Z., A.J.L.Q., T.H., J.W.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (D.K.S., B.P.); and Seattle Children's Hospital, Seattle, Washington (J.S., J.R.P.)
| | - Tao Hu
- Department of Pharmaceutics, University of Washington, Seattle, Washington (L.S.V., Y.Z., A.J.L.Q., T.H., J.W.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (D.K.S., B.P.); and Seattle Children's Hospital, Seattle, Washington (J.S., J.R.P.)
| | - Dilip Kumar Singh
- Department of Pharmaceutics, University of Washington, Seattle, Washington (L.S.V., Y.Z., A.J.L.Q., T.H., J.W.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (D.K.S., B.P.); and Seattle Children's Hospital, Seattle, Washington (J.S., J.R.P.)
| | - Jeffrey Stevens
- Department of Pharmaceutics, University of Washington, Seattle, Washington (L.S.V., Y.Z., A.J.L.Q., T.H., J.W.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (D.K.S., B.P.); and Seattle Children's Hospital, Seattle, Washington (J.S., J.R.P.)
| | - Bhagwat Prasad
- Department of Pharmaceutics, University of Washington, Seattle, Washington (L.S.V., Y.Z., A.J.L.Q., T.H., J.W.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (D.K.S., B.P.); and Seattle Children's Hospital, Seattle, Washington (J.S., J.R.P.)
| | - Julie R Park
- Department of Pharmaceutics, University of Washington, Seattle, Washington (L.S.V., Y.Z., A.J.L.Q., T.H., J.W.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (D.K.S., B.P.); and Seattle Children's Hospital, Seattle, Washington (J.S., J.R.P.)
| | - Joanne Wang
- Department of Pharmaceutics, University of Washington, Seattle, Washington (L.S.V., Y.Z., A.J.L.Q., T.H., J.W.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (D.K.S., B.P.); and Seattle Children's Hospital, Seattle, Washington (J.S., J.R.P.)
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5
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Evers R. Is Overexpression of the Plasma Membrane Transporter ( SLC29A4) a New Option to Stratify Patients with High-Risk Neuroblastoma for Treatment with 131I-mIBG? J Pharmacol Exp Ther 2023; 387:236-238. [PMID: 37967896 DOI: 10.1124/jpet.123.001875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 08/23/2023] [Indexed: 11/17/2023] Open
Affiliation(s)
- Raymond Evers
- Preclinical Sciences and Translational Safety, Janssen Pharmaceuticals, Spring House, Pennsylvania
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Weber BL, Beaver JN, Gilman TL. Summarizing studies using constitutive genetic deficiency to investigate behavioural influences of uptake 2 monoamine transporters. Basic Clin Pharmacol Toxicol 2023; 133:439-458. [PMID: 36316031 PMCID: PMC10657738 DOI: 10.1111/bcpt.13810] [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: 08/05/2022] [Revised: 10/14/2022] [Accepted: 10/24/2022] [Indexed: 11/27/2022]
Abstract
Burgeoning literature demonstrates that monoamine transporters with high transport capacity but lower substrate affinity (i.e., uptake 2) contribute meaningfully to regulation of monoamine neurotransmitter signalling. However, studying behavioural influences of uptake 2 is hindered by an absence of selective inhibitors largely free of off-target, confounding effects. This contrasts with study of monoamine transporters with low transport capacity but high substrate affinity (i.e., uptake 1), for which there are many reasonably selective inhibitors. To circumvent this dearth of pharmacological tools for studying uptake 2, researchers have instead employed mice with constitutive genetic deficiency in three separate transporters. By studying baseline behavioural shifts, plus behavioural responses to environmental and pharmacological manipulations-the latter primarily targeting uptake 1-investigators have been creatively characterizing the behavioural, and often sex-specific, influences of uptake 2. This non-systematic mini review summarizes current uptake 2 behaviour literature, highlighting emphases on stress responsivity in organic cation transporter 2 (OCT2) work, psychostimulant responsivity in OCT3 and plasma membrane monoamine transporter (PMAT) investigations, and antidepressant responsivity in all three. Collectively, this small but growing body of work reiterates the necessity for development of selective uptake 2-inhibiting drugs, with reviewed studies suggesting that these might advance personalized treatment approaches.
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Affiliation(s)
- Brady L Weber
- Department of Psychological Sciences & Brain Health Research Institute, Kent State University, Kent, Ohio, USA
| | - Jasmin N Beaver
- Department of Psychological Sciences & Brain Health Research Institute, Kent State University, Kent, Ohio, USA
| | - T Lee Gilman
- Department of Psychological Sciences & Brain Health Research Institute, Kent State University, Kent, Ohio, USA
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Alwindi M, Bizanti A. Vesicular monoamine transporter (VMAT) regional expression and roles in pathological conditions. Heliyon 2023; 9:e22413. [PMID: 38034713 PMCID: PMC10687066 DOI: 10.1016/j.heliyon.2023.e22413] [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: 11/14/2022] [Revised: 09/28/2023] [Accepted: 11/10/2023] [Indexed: 12/02/2023] Open
Abstract
Vesicular monoamine transporters (VMATs) are key regulators of neurotransmitter release responsible for controlling numerous physiological, cognitive, emotional, and behavioral functions. They represent important therapeutic targets for numerous pathological conditions. There are two isoforms of VMAT transporter proteins that function as secondary active transporters into the vesicle for storage and release via exocytosis: VMAT1 (SLC18A1) and VMAT2 (SLC18A2) which differ in their function, quantity, and regional expression. VMAT2 has gained considerable interest as a therapeutic target and diagnostic marker. Inhibitors of VMAT2 have been used as an effective therapy for a range of pathological conditions. Additionally, the functionality and phenotypic classification of classical and nonclassical catecholaminergic neurons are identified by the presence of VMAT2 in catecholaminergic neurons. Dysregulation of VMAT2 is also implicated in many neuropsychiatric diseases. Despite the complex role of VMAT2, many aspects of its function remain unclear. Therefore, our aim is to expand our knowledge of the role of VMAT with a special focus on VMAT2 in different systems and cellular pathways which may potentially facilitate development of novel, more specific therapeutic targets. The current review provides a summary demonstrating the mechanism of action of VMAT, its functional role, and its contribution to disease progression and utilization as therapeutic targets.
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Affiliation(s)
- Malik Alwindi
- St George's University Hospital, London SW17 0QT, United Kingdom
| | - Ariege Bizanti
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA
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Grand-Guillaume J, Mansi R, Gaonkar RH, Zanger S, Fani M, Eugster PJ, Beck Popovic M, Grouzmann E, Abid K. CUDC-907, a dual PI3K/histone deacetylase inhibitor, increases meta-iodobenzylguanidine uptake ( 123/131I-mIBG) in vitro and in vivo: a promising candidate for advancing theranostics in neuroendocrine tumors. J Transl Med 2023; 21:604. [PMID: 37679770 PMCID: PMC10485979 DOI: 10.1186/s12967-023-04466-z] [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: 04/24/2023] [Accepted: 08/22/2023] [Indexed: 09/09/2023] Open
Abstract
BACKGROUND Neuroblastoma (NB) and pheochromocytoma/paraganglioma (PHEO/PGL) are neuroendocrine tumors. Imaging of these neoplasms is performed by scintigraphy after injection of radiolabeled meta-iodobenzylguanidine (mIBG), a norepinephrine analog taken up by tumoral cells through monoamine transporters. The pharmacological induction of these transporters is a promising approach to improve the imaging and therapy (theranostics) of these tumors. METHODS Transporters involved in mIBG internalization were identified by using transfected Human Embryonic Kidney (HEK) cells. Histone deacetylase inhibitors (HDACi) and inhibitors of the PI3K/AKT/mTOR pathway were tested in cell lines to study their effect on mIBG internalization. Studies in xenografted mice were performed to assess the effect of the most promising HDACi on 123I-mIBG uptake. RESULTS Transfected HEK cells demonstrated that the norepinephrine and dopamine transporter (NET and DAT) avidly internalizes mIBG. Sodium-4-phenylbutyrate (an HDACi), CUDC-907 (a dual HDACi and PI3K inhibitor), BGT226 (a PI3K inhibitor) and VS-5584 and rapamycin (two inhibitors of mTOR) increased mIBG internalization in a neuroblastoma cell line (IGR-NB8) by 2.9-, 2.1-, 2.5-, 1.5- and 1.3-fold, respectively, compared with untreated cells. CUDC-907 also increased mIBG internalization in two other NB cell lines and in one PHEO cell line. We demonstrated that mIBG internalization occurs primarily through the NET. In xenografted mice with IGR-NB8 cells, oral treatment with 5 mg/kg of CUDC-907 increased the tumor uptake of 123I-mIBG by 2.3- and 1.9-fold at 4 and 24 h post-injection, respectively, compared to the untreated group. CONCLUSIONS Upregulation of the NET by CUDC-907 lead to a better internalization of mIBG in vitro and in vivo.
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Affiliation(s)
- Joana Grand-Guillaume
- Catecholamine and Peptides Laboratory, Service of Clinical Pharmacology and Toxicology, Lausanne University Hospital and University of Lausanne, 1011, Lausanne, Switzerland
| | - Rosalba Mansi
- Division of Radiopharmaceutical Chemistry, Clinic of Radiology and Nuclear Medicine, University Hospital Basel, 4031, Basel, Switzerland
| | - Raghuvir H Gaonkar
- Division of Radiopharmaceutical Chemistry, Clinic of Radiology and Nuclear Medicine, University Hospital Basel, 4031, Basel, Switzerland
| | - Sandra Zanger
- Division of Radiopharmaceutical Chemistry, Clinic of Radiology and Nuclear Medicine, University Hospital Basel, 4031, Basel, Switzerland
| | - Melpomeni Fani
- Division of Radiopharmaceutical Chemistry, Clinic of Radiology and Nuclear Medicine, University Hospital Basel, 4031, Basel, Switzerland
| | - Philippe J Eugster
- Catecholamine and Peptides Laboratory, Service of Clinical Pharmacology and Toxicology, Lausanne University Hospital and University of Lausanne, 1011, Lausanne, Switzerland
| | - Maja Beck Popovic
- Pediatric Hematology-Oncology Unit, Woman-Mother-Child Department, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Eric Grouzmann
- Catecholamine and Peptides Laboratory, Service of Clinical Pharmacology and Toxicology, Lausanne University Hospital and University of Lausanne, 1011, Lausanne, Switzerland
| | - Karim Abid
- Catecholamine and Peptides Laboratory, Service of Clinical Pharmacology and Toxicology, Lausanne University Hospital and University of Lausanne, 1011, Lausanne, Switzerland.
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Pérez-Gómez N, Fernández-Ortega MD, Elizari-Roncal M, Santos-Mazo E, la Maza-Pereg LD, Calvo S, Alcaraz R, Sanz-Solas A, Vinuesa R, Saiz-Rodríguez M. Identification of clinical and pharmacogenetic factors influencing metformin response in Type 2 diabetes mellitus. Pharmacogenomics 2023; 24:651-663. [PMID: 37610884 DOI: 10.2217/pgs-2023-0109] [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: 08/25/2023] Open
Abstract
Metformin, a hypoglycemic drug for Type 2 diabetes mellitus, shows variability in pharmacokinetics and response due to membrane transporters. This study followed 34 Type 2 diabetes mellitus patients on metformin treatment. Genetic variants in 11 metformin transport-related genes were analyzed, revealing associations. Specifically, SLC47A1 rs2289669 A/A and SLC22A4 rs1050152 T/T genotypes correlated with glycated hemoglobin values at 6 months. SLC47A1 rs2289669 G/A genotype influenced glucose levels at 6 months, while SLC29A4 rs3889348 A/A, SLC47A1 rs2289669 A/A, SLC22A4 rs1050152 C/T and SLC47A2 rs12943590 A/A genotypes were linked to glucose levels at 12 months. Additionally, ABCB1 rs2032582 C/A and ABCG2 rs2231137 C/T genotypes impacted cholesterol levels at 12 months. These findings shed light on metformin response determinants, offering insights for further research.
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Affiliation(s)
- Noelia Pérez-Gómez
- Department of Health Sciences, University of Burgos, Burgos, Spain
- Research Unit, Fundación Burgos por la Investigación de la Salud (FBIS), Hospital Universitario de Burgos, Burgos, Spain
| | | | - Miren Elizari-Roncal
- Health Center Jose Luis Santamaría, Burgos Primary Health Care Management, Burgos, Spain
| | | | | | - Sara Calvo
- Research Unit, Fundación Burgos por la Investigación de la Salud (FBIS), Hospital Universitario de Burgos, Burgos, Spain
| | - Raquel Alcaraz
- Research Unit, Fundación Burgos por la Investigación de la Salud (FBIS), Hospital Universitario de Burgos, Burgos, Spain
| | - Antonio Sanz-Solas
- Research Unit, Fundación Burgos por la Investigación de la Salud (FBIS), Hospital Universitario de Burgos, Burgos, Spain
| | - Raquel Vinuesa
- Research Unit, Fundación Burgos por la Investigación de la Salud (FBIS), Hospital Universitario de Burgos, Burgos, Spain
| | - Miriam Saiz-Rodríguez
- Department of Health Sciences, University of Burgos, Burgos, Spain
- Research Unit, Fundación Burgos por la Investigación de la Salud (FBIS), Hospital Universitario de Burgos, Burgos, Spain
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10
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Torres-Vergara P, Rivera R, Escudero C, Penny J. Maternal and Fetal Expression of ATP-Binding Cassette and Solute Carrier Transporters Involved in the Brain Disposition of Drugs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1428:149-177. [PMID: 37466773 DOI: 10.1007/978-3-031-32554-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Evidence from preclinical and clinical studies demonstrate that pregnancy is a physiological state capable of modifying drug disposition. Factors including increased hepatic metabolism and renal excretion are responsible for impacting disposition, and the role of membrane transporters expressed in biological barriers, including the placental- and blood-brain barriers, has received considerable attention. In this regard, the brain disposition of drugs in the mother and fetus has been the subject of studies attempting to characterize the mechanisms by which pregnancy could alter the expression of ATP-binding cassette (ABC) and solute carrier (SLC) transporters. This chapter will summarize findings of the influence of pregnancy on the maternal and fetal expression of ABC and SLC transporters in the brain and the consequences of such changes on the disposition of therapeutic drugs.
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Affiliation(s)
- Pablo Torres-Vergara
- Departamento de Farmacia, Facultad de Farmacia, Universidad de Concepción, Concepción, Chile.
- Grupo de Investigación Vascular (GRIVAS), Universidad del Bio-Bio, Chillán, Chile.
| | - Robin Rivera
- Departamento de Farmacia, Facultad de Farmacia, Universidad de Concepción, Concepción, Chile
| | - Carlos Escudero
- Grupo de Investigación Vascular (GRIVAS), Universidad del Bio-Bio, Chillán, Chile
- Laboratorio de Fisiología Vascular, Facultad de Ciencias Básicas, Universidad del Bio Bio, Chillán, Chile
| | - Jeffrey Penny
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Health and Medicine, The University of Manchester, Manchester, UK
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11
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Sarkar S, Saika-Voivod I, Berry MD. Modelling of p-tyramine transport across human intestinal epithelial cells predicts the presence of additional transporters. Front Physiol 2022; 13:1009320. [PMID: 36505075 PMCID: PMC9733674 DOI: 10.3389/fphys.2022.1009320] [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: 08/01/2022] [Accepted: 09/22/2022] [Indexed: 11/12/2022] Open
Abstract
p-Tyramine (TYR) is an endogenous trace amine, which can also be synthesized by intestinal microbiota, and is present in commonly consumed diets. TYR is an agonist for the intracellular trace amine-associated receptor 1, which has been implicated in psychiatric, metabolic, and immune-related disorders. We have previously demonstrated TYR readily diffuses across lipid bilayers, while transport across Caco-2 cell membranes involves Organic Cation Transporter 2 (OCT2) and a Na+-dependent active transporter. Here we developed mathematical models to determine whether known kinetics for these processes are sufficient to explain observed transcellular TYR passage. Ordinary differential equations were developed for known TYR transport processes to predict concentration-time relationships. Michaelis-Menten kinetics were assumed for all transporter-mediated processes and a one phase exponential function used for simple diffusion. Modelled concentration-time plots were compared to published experimental results. Additional transporter functions were sequentially added to models to improve consistency, and a least squares error minimization approach utilized to determine added transporter kinetics. Finally, possible TYR compartmentalization was also modelled. Following apical loading, transport across the apical, but not the basolateral, membrane was modelled without additional transporters, suggesting a basolateral transporter was missing. Consistent with this, models of basolateral compartment loading did not match experimental observations, indicating missing basolateral transporters were bidirectional. Addition of a transporter with the kinetic characteristics of OCT2 did not improve models. Varying the kinetic parameters of the added transporter improved models of basolateral, but worsened apical, loading models, suggesting the need for either a directional preference in transporters, or intracellular TYR compartmentalization. Experimental parameters were recapitulated by introducing asymmetry into the apical OCT2 (Kt_OCT2_apicaltocell = 110.4 nM, Kt_OCT2_celltoapical = 1,227.9 nM), and a symmetric basolateral facilitated diffusion transporter (Vmax = 6.0 nM/s, Kt = 628.3 nM). The apparent directionality of OCT2 may reflect altered TYR ionization due to known pH differences between compartments. Models for asymmetry and compartmentalization were compared by root mean square deviation from experimental data, and it was found that TYR compartmentalization could only partially replace the need for asymmetry of OCT2. In conclusion, modelling indicates that known TYR transport processes are insufficient to explain experimental concentration-time profiles and that asymmetry of the apical membrane OCT2 combined with additional, low affinity, basolateral membrane facilitated diffusion transporters are required.
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Affiliation(s)
- Shreyasi Sarkar
- Department of Biochemistry, Memorial University of Newfoundland, St. John’s, NL, Canada,*Correspondence: Shreyasi Sarkar,
| | - Ivan Saika-Voivod
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Mark D. Berry
- Department of Biochemistry, Memorial University of Newfoundland, St. John’s, NL, Canada
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12
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Antioxidant and Neuroprotective Effects of Paeonol against Oxidative Stress and Altered Carrier-Mediated Transport System on NSC-34 Cell Lines. Antioxidants (Basel) 2022; 11:antiox11071392. [PMID: 35883881 PMCID: PMC9311606 DOI: 10.3390/antiox11071392] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/11/2022] [Accepted: 07/14/2022] [Indexed: 02/05/2023] Open
Abstract
Paeonol is a naturally occurring phenolic agent that attenuates neurotoxicity in neurodegenerative diseases. We aimed to investigate the antioxidant and protective effects of paeonol and determine its transport mechanism in wild-type (WT; NSC-34/hSOD1WT) and mutant-type (MT; NSC-34/hSOD1G93A) motor neuron-like amyotrophic lateral sclerosis (ALS) cell lines. Cytotoxicity induced by glutamate, lipopolysaccharides, and H2O2 reduced viability of cell; however, the addition of paeonol improved cell viability against neurotoxicity. The [3H]paeonol uptake was increased in the presence of H2O2 in both cell lines. Paeonol recovered ALS model cell lines by reducing mitochondrial oxidative stress induced by glutamate. The transport of paeonol was time-, concentration-, and pH-dependent in both NSC-34 cell lines. Kinetic parameters showed two transport sites with altered affinity and capacity in the MT cell line compared to the WT cell line. [3H]Paeonol uptake increased in the MT cell line transfected with organic anion transporter1 (Oat1)/Slc22a6 small interfering RNA compared to that in the control. Plasma membrane monoamine transporter (Pmat) was also involved in the uptake of paeonol by ALS model cell lines. Overall, paeonol exhibits neuroprotective activity via a carrier-mediated transport system and may be a beneficial therapy for preventing motor neuronal damage under ALS-like conditions.
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13
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Beaver JN, Weber BL, Ford MT, Anello AE, Kassis SK, Gilman TL. Uncovering Functional Contributions of PMAT ( Slc29a4) to Monoamine Clearance Using Pharmacobehavioral Tools. Cells 2022; 11:cells11121874. [PMID: 35741002 PMCID: PMC9220966 DOI: 10.3390/cells11121874] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/01/2022] [Accepted: 06/07/2022] [Indexed: 11/16/2022] Open
Abstract
Plasma membrane monoamine transporter (PMAT, Slc29a4) transports monoamine neurotransmitters, including dopamine and serotonin, faster than more studied monoamine transporters, e.g., dopamine transporter (DAT), or serotonin transporter (SERT), but with ~400–600-fold less affinity. A considerable challenge in understanding PMAT’s monoamine clearance contributions is that no current drugs selectively inhibit PMAT. To advance knowledge about PMAT’s monoamine uptake role, and to circumvent this present challenge, we investigated how drugs that selectively block DAT/SERT influence behavioral readouts in PMAT wildtype, heterozygote, and knockout mice of both sexes. Drugs typically used as antidepressants (escitalopram, bupropion) were administered acutely for readouts in tail suspension and locomotor tests. Drugs with psychostimulant properties (cocaine, D-amphetamine) were administered repeatedly to assess initial locomotor responses plus psychostimulant-induced locomotor sensitization. Though we hypothesized that PMAT-deficient mice would exhibit augmented responses to antidepressant and psychostimulant drugs due to constitutively attenuated monoamine uptake, we instead observed sex-selective responses to antidepressant drugs in opposing directions, and subtle sex-specific reductions in psychostimulant-induced locomotor sensitization. These results suggest that PMAT functions differently across sexes, and support hypotheses that PMAT’s monoamine clearance contribution emerges when frontline transporters (e.g., DAT, SERT) are absent, saturated, and/or blocked. Thus, known human polymorphisms that reduce PMAT function could be worth investigating as contributors to varied antidepressant and psychostimulant responses.
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14
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Hu T, Zha W, Sun A, Wang J. Live Tissue Imaging Reveals Distinct Transcellular Pathways for Organic Cations and Anions at the Blood-Cerebrospinal Fluid Barrier. Mol Pharmacol 2022; 101:334-342. [PMID: 35193935 PMCID: PMC9092482 DOI: 10.1124/molpharm.121.000439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 01/31/2022] [Indexed: 11/22/2022] Open
Abstract
Formed by the choroid plexus epithelial (CPE) cells, the blood-cerebrospinal fluid barrier (BCSFB) plays an active role in removing drugs, toxins, and metabolic wastes from the brain. Several organic cation and anion transporters are expressed in the CPE cells, but how they functionally mediate transepithelial transport of organic cations and anions remain unclear. In this study, we visualized the transcellular transport of fluorescent organic cation and organic anion probes using live tissue imaging in freshly isolated mouse choroid plexuses (CPs). The cationic probe, 4-[4-(dimethylamino)phenyl]-1-methylpyridinium iodide (IDT307) was transported into CPE cells at the apical membrane and highly accumulated in mitochondria. Consistent with the lack of expression of organic cation efflux transporters, there was little efflux of IDT307 into the blood capillary space. Furthermore, IDT307 uptake and intracellular accumulation was attenuated by approximately 70% in CP tissues from mice with targeted deletion of the plasma membrane monoamine transporter (Pmat). In contrast, the anionic probe fluorescein-methotrexate (FL-MTX) was rapidly transported across the CPE cells into the capillary space with little intracellular accumulation. Rifampicin, an inhibitor of organic anion transporting polypeptides (OATPs), completely blocked FL-MTX uptake into the CPE cells whereas MK-571, a pan-inhibitor of multidrug resistance associated proteins (MRPs), abolished basolateral efflux of FL-MTX. In summary, our results suggest distinct transcellular transport pathways for organic cations and anions at the BCSFB and reveal a pivotal role of PMAT, OATP and MRP transporters in organic cation and anion transport at the blood-cerebrospinal fluid interface. SIGNIFICANCE STATEMENT: Live tissue imaging revealed that while organic cations are transported from the cerebrospinal fluid (CSF) into the choroid plexus epithelial cells by plasma membrane monoamine transporter without efflux into the blood, amphipathic anions in the CSF are efficiently transported across the BCSFB through the collaborated function of apical organic anion transporting polypeptides and basolateral multidrug resistance associated proteins. These findings contribute to a mechanistic understanding of the molecular and cellular pathways for choroid plexus clearance of solutes from the brain.
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Affiliation(s)
- Tao Hu
- Department of Pharmaceutics, University of Washington, Seattle, Washington
| | - Weibin Zha
- Department of Pharmaceutics, University of Washington, Seattle, Washington
| | - Austin Sun
- Department of Pharmaceutics, University of Washington, Seattle, Washington
| | - Joanne Wang
- Department of Pharmaceutics, University of Washington, Seattle, Washington
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15
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Lopez Quiñones AJ, Vieira LS, Wang J. Clinical Applications and the Roles of Transporters in Disposition, Tumor Targeting, and Tissue Toxicity of meta-Iodobenzylguanidine (mIBG). Drug Metab Dispos 2022; 50:DMD-MR-2021-000707. [PMID: 35197314 PMCID: PMC9488973 DOI: 10.1124/dmd.121.000707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 02/01/2022] [Accepted: 02/17/2022] [Indexed: 11/22/2022] Open
Abstract
Transporters on the plasma membrane of tumor cells are promising molecular "Trojan horses" to deliver drugs and imaging agents into cancer cells. Radioiodine-labeled meta-iodobenzylguanidine (mIBG) is used as a diagnostic agent (123I-mIBG) and a targeted radiotherapy (131I-mIBG) for neuroendocrine cancers. mIBG enters cancer cells through the norepinephrine transporter (NET) where the radioactive decay of 131I causes DNA damage, cell death, and tumor necrosis. mIBG is predominantly eliminated unchanged by the kidney. Despite its selective uptake by neuroendocrine tumors, mIBG accumulates in several normal tissues and leads to tissue-specific radiation toxicities. Emerging evidences suggest that the polyspecific organic cation transporters play important roles in systemic disposition and tissue-specific uptake of mIBG. In particular, human organic cation transporter 2 (hOCT2) and toxin extrusion proteins 1 and 2-K (hMATE1/2-K) likely mediate renal secretion of mIBG whereas hOCT1 and hOCT3 may contribute to mIBG uptake into normal tissues such as the liver, salivary glands, and heart. This mini-review focuses on the clinical applications of mIBG in neuroendocrine cancers and the differential roles of NET, OCT and MATE transporters in mIBG disposition, response and toxicity. Understanding the molecular mechanisms governing mIBG transport in cancer and normal cells is a critical step for developing strategies to optimize the efficacy of 131I-mIBG while minimizing toxicity in normal tissues. Significance Statement Radiolabeled mIBG has been used as a diagnostic tool and as radiotherapy for neuroendocrine cancers and other diseases. NET, OCT and MATE transporters play differential roles in mIBG tumor targeting, systemic elimination, and accumulation in normal tissues. The clinical use of mIBG as a radiopharmaceutical in cancer diagnosis and treatment can be further improved by taking a holistic approach considering mIBG transporters in both cancer and normal tissues.
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Affiliation(s)
| | | | - Joanne Wang
- Dept. of Pharmaceutics, University of Washington, United States
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16
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Sex differences in the transcription of monoamine transporters in major depression. J Affect Disord 2021; 295:1215-1219. [PMID: 34706435 DOI: 10.1016/j.jad.2021.08.124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 08/03/2021] [Accepted: 08/29/2021] [Indexed: 11/20/2022]
Abstract
BACKGROUND Accumulating evidence indicates that reduced activity within the monoamine systems contributes to the pathophysiology of major depressive disorder (MDD) and suicide. In this study, we have tested the hypothesis that monoaminergic gene transcription is abnormally regulated in MDD and suicide. METHODS The transcription of specific monoaminergic genes was quantified by qPCR in the dorsolateral prefrontal cortex (DLPFC) of postmortem MDD subjects (n = 80) and non-psychiatric controls (CTRL, n = 32). We measured transcripts encoding monoaminergic transporters (the serotonin transporter (SERT), norepinephrine transporter (NET), dopamine transporter (DAT), plasma monoamine transporter (PMAT), vesicular monoamine transporter (VMAT)) in addition to the tryptophan hydroxylase (TPH) enzymes, TPH1 and TPH2. We tested for transcriptional differences between diagnostic groups and tested for differences in the depressed suicides. RESULTS Multivariate analysis of monoaminergic gene transcription revealed a sex by diagnosis interaction (F8,99 = 2.87, p = 0.007). We report lower VMAT1 and PMAT expression in depressed males, and conversely higher VMAT2, TPH2 and NET expression in depressed females, relative to controls of the same sex (p < 0.05). We did not detect differences in monoamine gene transcription between the depressed suicides and depressed non-suicides. LIMITATIONS Gene expression measures were not associated with the presence of antidepressant medication. Nevertheless, to minimize the impact of medication status and other potential confounding variables, these were included as covariates in our analyses. CONCLUSIONS We report sex differences in the transcription of monoaminergic genes in the DLPFC in MDD. Therefore abnormalities of monoaminergic gene expression may contribute to altered DLPFC activity exhibited in major depression.
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17
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Interaction Profiles of Central Nervous System Active Drugs at Human Organic Cation Transporters 1-3 and Human Plasma Membrane Monoamine Transporter. Int J Mol Sci 2021; 22:ijms222312995. [PMID: 34884800 PMCID: PMC8657792 DOI: 10.3390/ijms222312995] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/26/2021] [Accepted: 11/28/2021] [Indexed: 12/31/2022] Open
Abstract
Many psychoactive compounds have been shown to primarily interact with high-affinity and low-capacity solute carrier 6 (SLC6) monoamine transporters for norepinephrine (NET; norepinephrine transporter), dopamine (DAT; dopamine transporter) and serotonin (SERT; serotonin transporter). Previous studies indicate an overlap between the inhibitory capacities of substances at SLC6 and SLC22 human organic cation transporters (SLC22A1-3; hOCT1-3) and the human plasma membrane monoamine transporter (SLC29A4; hPMAT), which can be classified as high-capacity, low-affinity monoamine transporters. However, interactions between central nervous system active substances, the OCTs, and the functionally-related PMAT have largely been understudied. Herein, we report data from 17 psychoactive substances interacting with the SLC6 monoamine transporters, concerning their potential to interact with the human OCT isoforms and hPMAT by utilizing radiotracer-based in vitro uptake inhibition assays at stably expressing human embryonic kidney 293 cells (HEK293) cells. Many compounds inhibit substrate uptake by hOCT1 and hOCT2 in the low micromolar range, whereas only a few substances interact with hOCT3 and hPMAT. Interestingly, methylphenidate and ketamine selectively interact with hOCT1 or hOCT2, respectively. Additionally, 3,4-methylenedioxymethamphetamine (MDMA) is a potent inhibitor of hOCT1 and 2 and hPMAT. Enantiospecific differences of R- and S-α-pyrrolidinovalerophenone (R- and S-α-PVP) and R- and S-citalopram and the effects of aromatic substituents are explored. Our results highlight the significance of investigating drug interactions with hOCTs and hPMAT, due to their role in regulating monoamine concentrations and xenobiotic clearance.
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18
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Serotonin modulates melatonin synthesis as an autocrine neurotransmitter in the pineal gland. Proc Natl Acad Sci U S A 2021; 118:2113852118. [PMID: 34675083 DOI: 10.1073/pnas.2113852118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2021] [Indexed: 01/23/2023] Open
Abstract
The pineal gland secretes melatonin principally at night. Regulated by norepinephrine released from sympathetic nerve terminals, adrenergic receptors on pinealocytes activate aralkylamine N-acetyltransferase that converts 5-hydroxytryptamine (5-HT, serotonin) to N-acetylserotonin, the precursor of melatonin. Previous studies from our group and others reveal significant constitutive secretion of 5-HT from pinealocytes. Here, using mass spectrometry, we demonstrated that the 5-HT is secreted primarily via a decynium-22-sensitive equilibrative plasma membrane monoamine transporter instead of by typical exocytotic quantal secretion. Activation of the endogenous 5-HT receptors on pinealocytes evoked an intracellular Ca2+ rise that was blocked by RS-102221, an antagonist of 5-HT2C receptors. Applied 5-HT did not evoke melatonin secretion by itself, but it did potentiate melatonin secretion evoked by submaximal norepinephrine. In addition, RS-102221 reduced the norepinephrine-induced melatonin secretion in strips of pineal gland, even when no exogenous 5-HT was added, suggesting that the 5-HT that is constitutively released from pinealocytes accumulates enough in the tissue to act as an autocrine feedback signal sensitizing melatonin release.
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19
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Maximino C. Decynium-22 affects behavior in the zebrafish light/dark test. NEUROANATOMY AND BEHAVIOUR 2021. [DOI: 10.35430/nab.2021.e21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Decynium-22 (D-22) is an inhibitor of the uptake2 system of monoamine clearance, resulting in increased levels of dopamine and norepinephrine (and in some cases serotonin) in the nervous system and elsewhere. Uptake2 is mediated by low-affinity, high-capacity transporters that are inhibited by glucocorticoids, suggesting a mechanism of fast glucocorticoid-monoamine interaction in the brain and a possible target for antidepressants. D-22 dose-dependently increased anxiety-like behavior in adult zebrafish exposed to the light/dark test, monotonically increasing scototaxis (dark preference), but affecting risk assessment with an inverted-U-shaped response. These results suggest that the uptake2 system has a role in defensive behavior in zebrafish, presenting a novel mechanism by which stress and glucocorticoids could produce fast neurobehavioral adjustments in vertebrates.
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20
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Differential Serotonin Uptake Mechanisms at the Human Maternal-Fetal Interface. Int J Mol Sci 2021; 22:ijms22157807. [PMID: 34360573 PMCID: PMC8346107 DOI: 10.3390/ijms22157807] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/16/2021] [Accepted: 07/18/2021] [Indexed: 12/30/2022] Open
Abstract
Serotonin (5-HT) plays an extensive role during pregnancy in regulating both the placental physiology and embryonic/fetal development. The uptake of 5-HT into cells is central to the control of local concentrations of 5-HT near its molecular targets. Here, we investigated the mechanisms of 5-HT uptake into human primary placental cells and cord blood platelets, all isolated immediately after birth. Trophoblasts and cord blood platelets showed 5-HT uptake with similar Michaelis constant (Km) values (~0.6 μM), typical of the high-affinity serotonin transporter (SERT). The uptake of 5-HT into trophoblasts was efficiently inhibited by various SERT-targeting drugs. In contrast, the uptake of 5-HT into feto-placental endothelial cells was not inhibited by a SERT blocker and showed a Km value (~782 μM) in the low-affinity range. Consistent with this, SERT mRNAs were abundant in term trophoblasts but sparse in feto-placental endothelial cells, whereas the opposite was found for the low-affinity plasma membrane monoamine transporter (PMAT) mRNAs. Organic cation transporter (OCT) 1, 2, and 3 mRNAs were absent or sparse in both cell types. In summary, the results demonstrate, for the first time, the presence of functional 5-HT uptake systems in feto-placental endothelial cells and fetal platelets, cells that are in direct contact with fetal blood plasma. The data also highlight the sensitivity to various psychotropic drugs of 5-HT transport into trophoblasts facing the maternal blood. The multiple, high-, and low-affinity systems present for the cellular uptake of 5-HT underscore the importance of 5-HT homeostasis at the maternal-fetal interface.
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21
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Abstract
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed medications for psychiatric disorders, yet they leave the majority of patients without full symptom relief. Therefore, a major research challenge is to identify novel targets for the improved treatment of these disorders. SSRIs act by blocking the serotonin transporter (SERT), the high-affinity, low-capacity, uptake-1 transporter for serotonin. Other classes of antidepressant work by blocking the norepinephrine or dopamine transporters (NET and DAT), the high-affinity, low-capacity uptake-1 transporters for norepinephrine and dopamine, or by blocking combinations of SERT, NET, and DAT. It has been proposed that uptake-2 transporters, which include organic cation transporters (OCTs) and the plasma membrane monoamine transporter (PMAT), undermine the therapeutic utility of uptake-1 acting antidepressants. Uptake-2 transporters for monoamines have low affinity for these neurotransmitters, but a high capacity to transport them. Thus, activity of these transporters may limit the increase of extracellular monoamines thought to be essential for ultimate therapeutic benefit. Here preclinical evidence supporting a role for OCT2, OCT3, and PMAT in behaviors relevant to psychiatric disorders is presented. Importantly, preclinical evidence revealing these transporters as targets for the development of novel therapeutics for psychiatric disorders is discussed.
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22
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Koepsell H. Update on drug-drug interaction at organic cation transporters: mechanisms, clinical impact, and proposal for advanced in vitro testing. Expert Opin Drug Metab Toxicol 2021; 17:635-653. [PMID: 33896325 DOI: 10.1080/17425255.2021.1915284] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Introduction: Organic cation transporters collectively called OCTs belong to three gene families (SLC22A1 OCT1, SLC22A2 OCT2, SLC22A3 OCT3, SLC22A4 OCTN1, SLC22A5 OCTN2, SLC29A4 PMAT, SLC47A1 MATE1, and SLC47A1 MATE2-K). OCTs transport structurally diverse drugs with overlapping selectivity. Some OCTs were shown to be critically involved in pharmacokinetics and therapeutic efficacy of cationic drugs. Drug-drug interactions at individual OCTs were shown to result in clinical effects. Procedures for in vitro testing of drugs for interaction with OCT1, OCT2, MATE1, and MATE2-K have been recommended.Areas covered: An overview of functional properties, cation selectivity, location, and clinical impact of OCTs is provided. In addition, clinically relevant drug-drug interactions in OCTs are compiled. Because it was observed that the half maximal concentration of drugs to inhibit transport by OCTs (IC50) is dependent on the transported cation and its concentration, an advanced protocol for in vitro testing of drugs for interaction with OCTs is proposed. In addition, it is suggested to include OCT3 and PMAT for in vitro testing.Expert opinion: Research on clinical roles of OCTs should be reinforced including more transporters and drugs. An improvement of the in vitro testing protocol considering recent data is imperative for the benefit of patients.
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Affiliation(s)
- Hermann Koepsell
- Institute of Anatomy and Cell Biology, University Würzburg, Würzburg, Germany
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23
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Maier J, Rauter L, Rudin D, Niello M, Holy M, Schmid D, Wilson J, Blough BE, Gannon BM, Murnane KS, Sitte HH. α-PPP and its derivatives are selective partial releasers at the human norepinephrine transporter: A pharmacological characterization of interactions between pyrrolidinopropiophenones and high and low affinity monoamine transporters. Neuropharmacology 2021; 190:108570. [PMID: 33864800 DOI: 10.1016/j.neuropharm.2021.108570] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/31/2021] [Accepted: 04/12/2021] [Indexed: 12/31/2022]
Abstract
While classical cathinones, such as methcathinone, have been shown to be monoamine releasing agents at human monoamine transporters, the subgroup of α-pyrrolidinophenones has thus far solely been characterized as monoamine transporter reuptake inhibitors. Herein, we report data from previously undescribed α-pyrrolidinopropiophenone (α-PPP) derivatives and compare them with the pharmacologically well-researched α-PVP (α-pyrrolidinovalerophenone). Radiotracer-based in vitro uptake inhibition assays in HEK293 cells show that the investigated α-PPP derivatives inhibit the human high-affinity transporters of dopamine (hDAT) and norepinephrine (hNET) in the low micromolar range, with α-PVP being ten times more potent. Similar to α-PVP, no relevant pharmacological activity was found at the human serotonin transporter (hSERT). Unexpectedly, radiotracer-based in vitro release assays reveal α-PPP, MDPPP and 3Br-PPP, but not α-PVP, to be partial releasing agents at hNET (EC50 values in the low micromolar range). Furthermore, uptake inhibition assays at low-affinity monoamine transporters, i.e., the human organic cation transporters (hOCT) 1-3 and human plasma membrane monoamine transporter (hPMAT), bring to light that all compounds inhibit hOCT1 and 2 (IC50 values in the low micromolar range) while less potently interacting with hPMAT and hOCT3. In conclusion, this study describes (i) three new hybrid compounds that efficaciously block hDAT while being partial releasers at hNET, and (ii) highlights the interactions of α-PPP-derivatives with low-affinity monoamine transporters, giving impetus to further studies investigating the interaction of drugs of abuse with OCT1-3 and PMAT.
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Affiliation(s)
- Julian Maier
- Medical University of Vienna, Center for Physiology and Pharmacology, Institute of Pharmacology, Währingerstraße 13A, 1090, Vienna, Austria
| | - Laurin Rauter
- Medical University of Vienna, Center for Physiology and Pharmacology, Institute of Pharmacology, Währingerstraße 13A, 1090, Vienna, Austria
| | - Deborah Rudin
- Medical University of Vienna, Center for Physiology and Pharmacology, Institute of Pharmacology, Währingerstraße 13A, 1090, Vienna, Austria
| | - Marco Niello
- Medical University of Vienna, Center for Physiology and Pharmacology, Institute of Pharmacology, Währingerstraße 13A, 1090, Vienna, Austria
| | - Marion Holy
- Medical University of Vienna, Center for Physiology and Pharmacology, Institute of Pharmacology, Währingerstraße 13A, 1090, Vienna, Austria
| | - Diethart Schmid
- Medical University of Vienna, Center for Physiology and Pharmacology, Institute of Physiology, Währingerstraße 13A, 1090, Vienna, Austria
| | - Joseph Wilson
- Research Triangle Institute, Center for Drug Discovery, Research Triangle Park, NC, USA
| | - Bruce E Blough
- Research Triangle Institute, Center for Drug Discovery, Research Triangle Park, NC, USA
| | - Brenda M Gannon
- Mercer University College of Pharmacy, Mercer University Health Sciences Center, Department of Pharmaceutical Sciences, Atlanta, GA, USA; Louisiana State University Health Sciences Center, Shreveport, Department of Pharmacology Toxicology & Neuroscience and Louisiana Addiction Research Center, Shreveport, LA, USA
| | - Kevin S Murnane
- Mercer University College of Pharmacy, Mercer University Health Sciences Center, Department of Pharmaceutical Sciences, Atlanta, GA, USA; Louisiana State University Health Sciences Center, Shreveport, Department of Pharmacology Toxicology & Neuroscience and Louisiana Addiction Research Center, Shreveport, LA, USA
| | - Harald H Sitte
- Medical University of Vienna, Center for Physiology and Pharmacology, Institute of Pharmacology, Währingerstraße 13A, 1090, Vienna, Austria; AddRess Centre for Addiction Research and Science, Medical University of Vienna, Währingerstraße 13A, 1090, Vienna, Austria.
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24
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Abstract
Catecholamines, including dopamine, norepinephrine, and epinephrine, are modulatory transmitters released from specialized neurons throughout the brain. Collectively, catecholamines exert powerful regulation of mood, motivation, arousal, and plasticity. Transporter-mediated uptake determines the peak concentration, duration, and physical spread of released catecholamines, thus playing key roles in determining the magnitude and duration of their modulatory effects. Most studies of catecholamine clearance have focused on the presynaptic high-affinity, low-capacity dopamine (DAT), and norepinephrine (NET) transporters, which are members of the uptake1 family of monoamine transporters. However, recent studies have demonstrated that members of the uptake2 family of monoamine transporters, including organic cation transporter 2 (OCT2), OCT3, and the plasma membrane monoamine transporter (PMAT) are expressed widely throughout the brain. In contrast to DAT and NET, these transporters have higher capacity and lower affinity for catecholamines and are multi-specific, each with the capacity to transport all catecholamines. The expression of these transporters in the brain suggests that they play significant roles in regulating catecholamine homeostasis. This review summarizes studies describing the anatomical distribution of OCT2, OCT3, and PMAT, their cellular and subcellular localization, and their contribution to the regulation of the clearance of catecholamines in the brain.
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25
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Sweet DH. Organic Cation Transporter Expression and Function in the CNS. Handb Exp Pharmacol 2021; 266:41-80. [PMID: 33963461 DOI: 10.1007/164_2021_463] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB) represent major control checkpoints protecting the CNS, by exerting selective control over the movement of organic cations and anions into and out of the CNS compartment. In addition, multiple CNS cell types, e.g., astrocytes, ependymal cells, microglia, contribute to processes that maintain the status quo of the CNS milieu. To fulfill their roles, these barriers and cell types express a multitude of transporter proteins from dozens of different transporter families. Fundamental advances over the past few decades in our knowledge of transporter substrates, expression profiles, and consequences of loss of function are beginning to change basic theories regarding the contribution of various cell types and clearance networks to coordinated neuronal signaling, complex organismal behaviors, and overall CNS homeostasis. In particular, transporters belonging to the Solute Carrier (SLC) superfamily are emerging as major contributors, including the SLC22 organic cation/anion/zwitterion family of transporters (includes OCT1-3 and OCTN1-3), the SLC29 facilitative nucleoside family of transporters (includes PMAT), and the SLC47 multidrug and toxin extrusion family of transporters (includes MATE1-2). These transporters are known to interact with neurotransmitters, antidepressant and anxiolytic agents, and drugs of abuse. Clarifying their contributions to the underlying mechanisms regulating CNS permeation and clearance, as well as the health status of astrocyte, microglial and neuronal cell populations, will drive new levels of understanding as to maintenance of the CNS milieu and approaches to new therapeutics and therapeutic strategies in the treatment of CNS disorders. This chapter highlights organic cation transporters belonging to the SLC superfamily known to be expressed in the CNS, providing an overview of their identification, mechanism of action, CNS expression profile, interaction with neurotransmitters and antidepressant/antipsychotic drugs, and results from behavioral studies conducted in loss of function models (knockout/knockdown).
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Affiliation(s)
- Douglas H Sweet
- Department of Pharmaceutics, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, USA.
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26
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Sun A, Wang J. Choroid Plexus and Drug Removal Mechanisms. AAPS JOURNAL 2021; 23:61. [PMID: 33942198 DOI: 10.1208/s12248-021-00587-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/24/2021] [Indexed: 01/08/2023]
Abstract
Timely and efficient removal of xenobiotics and metabolites from the brain is crucial in maintaining the homeostasis and normal function of the brain. The choroid plexus (CP) forms the blood-cerebrospinal fluid barrier and vitally removes drugs and wastes from the brain through several co-existing clearance mechanisms. The CP epithelial (CPE) cells synthesize and secrete the cerebrospinal fluid (CSF). As the CSF passes through the ventricular and subarachnoid spaces and eventually drains into the general circulation, it collects and removes drugs, toxins, and metabolic wastes from the brain. This bulk flow of the CSF serves as a default and non-selective pathway for the removal of solutes and macromolecules from the brain interstitium. Besides clearance by CSF bulk flow, the CPE cells express several multispecific membrane transporters to actively transport substrates from the CSF side into the blood side. In addition, several phase I and II drug-metabolizing enzymes are expressed in the CPE cells, which enzymatically inactivate a broad spectrum of reactive or toxic substances. This review summarizes our current knowledge of the functional characteristics and key contributors to the various clearance pathways in the CP-CSF system, overviewing recent developments in our understanding of CSF flow dynamics and the functional roles of CP uptake and efflux transporters in influencing CSF drug concentrations.
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Affiliation(s)
- Austin Sun
- Department of Pharmaceutics, University of Washington, Health Science Building Room H-272J, Box 357610, Seattle, Washington, 98195-7610, USA
| | - Joanne Wang
- Department of Pharmaceutics, University of Washington, Health Science Building Room H-272J, Box 357610, Seattle, Washington, 98195-7610, USA.
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Wei R, Gust SL, Tandio D, Maheux A, Nguyen KH, Wang J, Bourque S, Plane F, Hammond JR. Deletion of murine slc29a4 modifies vascular responses to adenosine and 5-hydroxytryptamine in a sexually dimorphic manner. Physiol Rep 2021; 8:e14395. [PMID: 32170814 PMCID: PMC7070170 DOI: 10.14814/phy2.14395] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 12/15/2022] Open
Abstract
Equilibrative nucleoside transporter 4 (ENT4), encoded by SLC29A4, mediates the flux of both 5‐hydroxytryptamine (5‐HT) and adenosine across cell membranes. We hypothesized that loss of ENT4 function in mice would modify the effects of these established regulators of vascular function. Male and female wild‐type (WT) and slc29a4‐null (ENT4‐KO) mice were compared with respect to their hemodynamics and mesenteric vascular function. Male ENT4‐KO mice had a complete loss of myogenic tone in their mesenteric resistance arteries. This was accompanied by a decrease in blood flow in the superior mesenteric artery in the male ENT4‐KO mice, and a reduced responsiveness to 5‐HT. In contrast, endothelium‐dependent relaxations of mesenteric arteries from female ENT4‐KO mice were more sensitive to Ca2+‐activated K+ (KCa) channel blockade than WT mice. Female ENT4‐KO mice also demonstrated an enhanced vasodilatory response to adenosine in vivo that was not seen in males. Ketanserin (5‐HT2A inhibitor) and GR55562 (5‐HT1B/1D inhibitor) decreased 5‐HT‐induced tone, but only ketanserin inhibited the relaxant effect of 5‐HT in mesenteric arteries. 5‐HT‐evoked increases in tone were elevated in arteries from ENT4‐KO mice upon block of endothelial relaxant pathways, with arteries from female ENT4‐KO mice showing the greatest increase. Adenosine A2b receptor expression was decreased, while other adenosine transporter subtypes, as well as adenosine deaminase and adenosine kinase were increased in mesenteric arteries from male, but not female, ENT4‐KO mice. These findings indicate that deletion of slc29a4 leads to sex‐specific changes in vascular function with significant consequences for regulation of blood flow and pressure by adenosine and 5‐HT.
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Affiliation(s)
- Ran Wei
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Stephen L Gust
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - David Tandio
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Alexia Maheux
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Khanh H Nguyen
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Joanne Wang
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Stephane Bourque
- Department of Anaesthesia and Pain Medicine, University of Alberta, Edmonton, AB, Canada
| | - Frances Plane
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - James R Hammond
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
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Noguchi S, Takagi A, Tanaka T, Takahashi Y, Pan X, Kibayashi Y, Mizokami R, Nishimura T, Tomi M. Fluorouracil uptake in triple-negative breast cancer cells: Negligible contribution of equilibrative nucleoside transporters 1 and 2. Biopharm Drug Dispos 2021; 42:85-93. [PMID: 33426680 DOI: 10.1002/bdd.2261] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 12/15/2020] [Accepted: 12/20/2020] [Indexed: 01/07/2023]
Abstract
Equilibrative nucleoside transporters (ENTs) 1 and 2 reportedly accept fluorouracil as a substrate. Here, we evaluated ENT1/2 expression at the messenger RNA (mRNA), protein, and functional levels in a panel of four triple-negative breast cancer (TNBC) cell lines, BT-549, Hs578T, MDA-MB-231, and MDA-MB-435, and we examined the relationship of the observed profiles to fluorouracil sensitivity. Nitrobenzylthioinosine (NBMPR) at 0.1 μM inhibits only ENT1, while dipyridamole at 10 μM or NBMPR at 100 μM inhibits both ENT1 and ENT2. We found that the uptake of [3 H]uridine, a typical substrate of ENT1 and ENT2, was decreased to approximately 40% by 0.1 μM NBMPR. At 100 μM, NBMPR almost completely blocked the saturable uptake of [3 H]uridine, but this does not imply a functional role of ENT2, because 10 μM dipyridamole showed similar inhibition to 0.1 μM NBMPR. Expression of ENT1 mRNA was almost 1 order of magnitude higher than that of ENT2 in all TNBC cell lines. Liquid chromatography-tandem mass spectrometry(LC-MS/MS) LC-MS/MS-based targeted protein quantification showed that ENT1 protein levels were in the range of 9.3-30 fmol/μg protein in plasma membrane fraction of TNBC cell lines, whereas ENT2 protein was below the detection limit. [3 H]Fluorouracil uptake was insensitive to 0.1 μM NBMPR and 10 μM dipyridamole, suggesting a negligible contribution of ENT1 and ENT2 to fluorouracil uptake. The levels of ENT1 mRNA, ENT1 protein, ENT2 mRNA, and ENT1-mediated [3 H]uridine uptake in the four TNBC cell lines showed no correlation with fluorouracil sensitivity. These results indicate that neither ENT1 nor ENT2 contributes significantly to the fluorouracil sensitivity of TNBC cell lines.
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Affiliation(s)
- Saki Noguchi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Tokyo, Japan
| | - Akinori Takagi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Tokyo, Japan.,Laboratory of Applied Therapeutics, Showa Pharmaceutical University, Tokyo, Japan
| | - Takahiro Tanaka
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Tokyo, Japan
| | - Yu Takahashi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Tokyo, Japan
| | - Xiaole Pan
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Tokyo, Japan
| | - Yuka Kibayashi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Tokyo, Japan
| | - Ryo Mizokami
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Tokyo, Japan
| | - Tomohiro Nishimura
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Tokyo, Japan
| | - Masatoshi Tomi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Tokyo, Japan
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Maier J, Niello M, Rudin D, Daws LC, Sitte HH. The Interaction of Organic Cation Transporters 1-3 and PMAT with Psychoactive Substances. Handb Exp Pharmacol 2021; 266:199-214. [PMID: 33993413 DOI: 10.1007/164_2021_469] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Organic cation transporters 1-3 (OCT1-3, SLC22A1-3) and the plasma membrane monoamine transporter (PMAT, SLC29A4) play a major role in maintaining monoaminergic equilibrium in the central nervous system. With many psychoactive substances interacting with OCT1-3 and PMAT, a growing literature focuses on characterizing their properties via in vitro and in vivo studies. In vitro studies mainly aim at characterizing compounds as inhibitors or substrates of murine, rat, and human isoforms. The preponderance of studies has put emphasis on phenylalkylamine derivatives, but ketamine and opioids have also been investigated. Studies employing in vivo (knockout) models mostly concentrate on the interaction of psychoactive substances and OCT3, with an emphasis on stress and addiction, pharmacokinetics, and sensitization to psychoactive drugs. The results highlight the importance of OCT3 in the mechanism of action of psychoactive compounds. Concerning in vivo studies, a veritable research gap concerning OCT1, 2, and PMAT exists. This review provides an overview and summary of research conducted in this field of research.
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Affiliation(s)
- Julian Maier
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Marco Niello
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Deborah Rudin
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Lynette C Daws
- Department of Cellular and Integrative Physiology, University of Texas Health, San Antonio, TX, USA
- Department of Pharmacology, University of Texas Health, San Antonio, TX, USA
| | - Harald H Sitte
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria.
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Abstract
Inhibitors of Na+/Cl- dependent high affinity transporters for norepinephrine (NE), serotonin (5-HT), and/or dopamine (DA) represent frequently used drugs for treatment of psychological disorders such as depression, anxiety, obsessive-compulsive disorder, attention deficit hyperactivity disorder, and addiction. These transporters remove NE, 5-HT, and/or DA after neuronal excitation from the interstitial space close to the synapses. Thereby they terminate transmission and modulate neuronal behavioral circuits. Therapeutic failure and undesired central nervous system side effects of these drugs have been partially assigned to neurotransmitter removal by low affinity transport. Cloning and functional characterization of the polyspecific organic cation transporters OCT1 (SLC22A1), OCT2 (SLC22A2), OCT3 (SLC22A3) and the plasma membrane monoamine transporter PMAT (SLC29A4) revealed that every single transporter mediates low affinity uptake of NE, 5-HT, and DA. Whereas the organic transporters are all located in the blood brain barrier, OCT2, OCT3, and PMAT are expressed in neurons or in neurons and astrocytes within brain areas that are involved in behavioral regulation. Areas of expression include the dorsal raphe, medullary motoric nuclei, hypothalamic nuclei, and/or the nucleus accumbens. Current knowledge of the transport of monoamine neurotransmitters by the organic cation transporters, their interactions with psychotropic drugs, and their locations in the brain is reported in detail. In addition, animal experiments including behavior tests in wildtype and knockout animals are reported in which the impact of OCT2, OCT3, and/or PMAT on regulation of salt intake, depression, mood control, locomotion, and/or stress effect on addiction is suggested.
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Affiliation(s)
- Hermann Koepsell
- Institute of Anatomy and Cell Biology, University Würzburg, Würzburg, Germany.
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31
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Abstract
Precise control of monoamine neurotransmitter levels in the central nervous system (CNS) is crucial for proper brain function. Dysfunctional monoamine signaling is associated with several neuropsychiatric and neurodegenerative disorders. The plasma membrane monoamine transporter (PMAT) is a new polyspecific organic cation transporter encoded by the SLC29A4 gene. Capable of transporting monoamine neurotransmitters with low affinity and high capacity, PMAT represents a major uptake2 transporter in the brain. Broadly expressed in multiple brain regions, PMAT can complement the high-affinity, low-capacity monoamine uptake mediated by uptake1 transporters, the serotonin, dopamine, and norepinephrine transporters (SERT, DAT, and NET, respectively). This chapter provides an overview of the molecular and functional characteristics of PMAT together with its regional and cell-type specific expression in the mammalian brain. The physiological functions of PMAT in brain monoamine homeostasis are evaluated in light of its unique transport kinetics and brain location, and in comparison with uptake1 and other uptake2 transporters (e.g., OCT3) along with corroborating experimental evidences. Lastly, the possibility of PMAT's involvement in brain pathophysiological processes, such as autism, depression, and Parkinson's disease, is discussed in the context of disease pathology and potential link to aberrant monoamine pathways.
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Substrates and Inhibitors of Organic Cation Transporters (OCTs) and Plasma Membrane Monoamine Transporter (PMAT) and Therapeutic Implications. Handb Exp Pharmacol 2021; 266:119-167. [PMID: 34495395 DOI: 10.1007/164_2021_516] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The gene products of the SLC22A gene family (hOCT1, hOCT2, and hOCT3) and of the SLC29A4 gene (hPMAT or hENT4) are all polyspecific organic cation transporters. Human OCTs (including hPMAT) are expressed in peripheral tissues such as small intestine, liver, and kidney involved in the pharmacokinetics of drugs. In the human brain, all four transporters are expressed at the blood-brain barrier (BBB), hOCT2 is additionally expressed in neurons, and hOCT3 and hPMAT in glia. More than 40% of the presently used drugs are organic cations. This chapter lists and discusses all known drugs acting as substrates or inhibitors of these four organic cation transporters, independently of whether the transporter is expressed in the central nervous system (CNS) or in peripheral tissues. Of interest is their involvement in drug absorption, distribution, and excretion as well as potential OCT-associated drug-drug interactions (DDIs), with a focus on drugs that act in the CNS.
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Bhat S, El-Kasaby A, Freissmuth M, Sucic S. Functional and Biochemical Consequences of Disease Variants in Neurotransmitter Transporters: A Special Emphasis on Folding and Trafficking Deficits. Pharmacol Ther 2020; 222:107785. [PMID: 33310157 PMCID: PMC7612411 DOI: 10.1016/j.pharmthera.2020.107785] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/02/2020] [Indexed: 01/30/2023]
Abstract
Neurotransmitters, such as γ-aminobutyric acid, glutamate, acetyl choline, glycine and the monoamines, facilitate the crosstalk within the central nervous system. The designated neurotransmitter transporters (NTTs) both release and take up neurotransmitters to and from the synaptic cleft. NTT dysfunction can lead to severe pathophysiological consequences, e.g. epilepsy, intellectual disability, or Parkinson’s disease. Genetic point mutations in NTTs have recently been associated with the onset of various neurological disorders. Some of these mutations trigger folding defects in the NTT proteins. Correct folding is a prerequisite for the export of NTTs from the endoplasmic reticulum (ER) and the subsequent trafficking to their pertinent site of action, typically at the plasma membrane. Recent studies have uncovered some of the key features in the molecular machinery responsible for transporter protein folding, e.g., the role of heat shock proteins in fine-tuning the ER quality control mechanisms in cells. The therapeutic significance of understanding these events is apparent from the rising number of reports, which directly link different pathological conditions to NTT misfolding. For instance, folding-deficient variants of the human transporters for dopamine or GABA lead to infantile parkinsonism/dystonia and epilepsy, respectively. From a therapeutic point of view, some folding-deficient NTTs are amenable to functional rescue by small molecules, known as chemical and pharmacological chaperones.
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Affiliation(s)
- Shreyas Bhat
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 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, A-1090 Vienna, Austria
| | - 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, A-1090 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, A-1090 Vienna, Austria.
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Hirayama M, Hoshino Y, Yoshii K, Toda R, Kawabata Y, Nakanishi T, Tamai I. Identification of the Uptake Transporter Responsible for Distribution of Acotiamide into Stomach Tissue. Mol Pharm 2020; 17:1071-1078. [PMID: 32105080 DOI: 10.1021/acs.molpharmaceut.9b00894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The acetylcholinesterase inhibitor, acotiamide, improves gastric motility and is clinically used to treat functional dyspepsia. The present study aimed to identify the transporters involved in the distribution of acotiamide in stomach tissue. Acotiamide uptake by the gastric cancer-derived model cell line, Hs746 T, was Na+- and pH-independent. The initial uptake velocity of acotiamide was saturable with increasing concentrations of acotiamide and was inhibited by selective serotonin reuptake inhibitors, which are potent inhibitors of the plasma membrane monoamine transporter (PMAT). The uptake of acotiamide by PMAT gene-transfected HEK293 cells was saturable, with similar Km (197.9 μM) values to those of uptake by Hs 746T cells (106 μM). Moreover, immunoreactivity of PMAT was found in the gastric smooth muscle and vascular endothelial cells. These results suggest that PMAT contributes to the distribution of acotiamide in the stomach, where it exerts its pharmacological effects.
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Affiliation(s)
- Masamichi Hirayama
- Toxicology & Pharmacokinetics Research, Central Research Laboratories, Zeria Pharmaceutical Corporation Ltd., Saitama 360-0111, Japan.,Institute of Medical Pharmaceutical and Health Sciences, Faculty of Pharmacy, Kanazawa University, Kanazawa 920-1192, Japan
| | - Yusuke Hoshino
- Toxicology & Pharmacokinetics Research, Central Research Laboratories, Zeria Pharmaceutical Corporation Ltd., Saitama 360-0111, Japan
| | - Kazuyoshi Yoshii
- Toxicology & Pharmacokinetics Research, Central Research Laboratories, Zeria Pharmaceutical Corporation Ltd., Saitama 360-0111, Japan
| | - Ryoko Toda
- Toxicology & Pharmacokinetics Research, Central Research Laboratories, Zeria Pharmaceutical Corporation Ltd., Saitama 360-0111, Japan
| | - Yoshihiro Kawabata
- Toxicology & Pharmacokinetics Research, Central Research Laboratories, Zeria Pharmaceutical Corporation Ltd., Saitama 360-0111, Japan
| | - Takeo Nakanishi
- Institute of Medical Pharmaceutical and Health Sciences, Faculty of Pharmacy, Kanazawa University, Kanazawa 920-1192, Japan
| | - Ikumi Tamai
- Institute of Medical Pharmaceutical and Health Sciences, Faculty of Pharmacy, Kanazawa University, Kanazawa 920-1192, Japan
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Hasegawa N, Furugen A, Ono K, Koishikawa M, Miyazawa Y, Nishimura A, Umazume T, Narumi K, Kobayashi M, Iseki K. Cellular uptake properties of lamotrigine in human placental cell lines: Investigation of involvement of organic cation transporters (SLC22A1-5). Drug Metab Pharmacokinet 2020; 35:266-273. [PMID: 32303459 DOI: 10.1016/j.dmpk.2020.01.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 01/07/2020] [Accepted: 01/26/2020] [Indexed: 01/11/2023]
Abstract
Lamotrigine (LTG) is an important antiepileptic drug for the treatment of seizures in pregnant women with epilepsy. However, it is not known if the transport of LTG into placental cells occurs via a carrier-mediated pathway. The aim of this study was to investigate the uptake properties of LTG into placental cell lines (BeWo and JEG-3), and to determine the involvement of organic cation transporters (OCTs, SLC22A1-3) and organic cation/carnitine transporter (OCTNs, SLC22A4-5) in the uptake process. The uptake of LTG at 37 °C was higher than that at 4 °C. OCT1 and OCTNs were detected in both cell lines. The uptake of LTG was not greatly affected by the extracellular pH, Na+-free conditions, or the presence of l-carnitine, suggesting that OCTNs were not involved. Although several potent inhibitors of OCTs (chloroquine, imipramine, quinidine, and verapamil) inhibited LTG uptake, other typical inhibitors had no effect. In addition, siRNA targeted to OCT1 had no significant effect on LTG uptake. The mRNA expression in human term placenta followed the order OCTN2 > OCT3 > OCTN1 > OCT1 ≈ OCT2. These observations suggested that LTG uptake into placental cells was carrier-mediated, but that OCTs and OCTNs were not responsible for the placental transport process.
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Affiliation(s)
- Nami Hasegawa
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Japan
| | - Ayako Furugen
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Japan
| | - Kanako Ono
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Japan
| | - Mai Koishikawa
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Japan
| | - Yuki Miyazawa
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Japan
| | - Ayako Nishimura
- Department of Pharmacy, Hokkaido University Hospital, Sapporo, Japan
| | - Takeshi Umazume
- Department of Obstetrics, Hokkaido University Hospital, Sapporo, Japan
| | - Katsuya Narumi
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Japan
| | - Masaki Kobayashi
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Japan.
| | - Ken Iseki
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Japan.
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Sonobe T, Akiyama T, Du C, Pearson JT. Serotonin uptake via plasma membrane monoamine transporter during myocardial ischemia-reperfusion in the rat heart in vivo. Physiol Rep 2019; 7:e14297. [PMID: 31782271 PMCID: PMC6882957 DOI: 10.14814/phy2.14297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Serotonin (5-HT) accumulates in the heart during myocardial ischemia and induces deleterious effects on the cardiomyocytes through receptor-dependent and monoamine oxidase-dependent pathways. We aimed to clarify the involvement of extra-neuronal monoamine transporters in the clearance of 5-HT during ischemia and reperfusion in the heart. Using a microdialysis technique in the anesthetized Wistar rat heart, we monitored myocardial interstitial 5-HT and 5-hydroxyindole acetic acid (5-HIAA) concentration by means of electro-chemical detection coupled with high-performance liquid chromatography (HPLC-ECD). Effects of inhibitors of the plasma membrane monoamine transporter (PMAT) and the organic cation transporter 3 (OCT3) (decynium-22 and corticosterone) on the 5-HT and 5-HIAA concentrations during baseline, coronary occlusion, and reperfusion were investigated. Basal dialysate 5-HT concentration were increased by local administration of decynium-22, but not by corticosterone. Addition of fluoxetine, a serotonin transporter (SERT) inhibitor further increased the 5-HT concentration upon during administration of decynium-22. Decynium-22 elevated the background level of 5-HT during coronary occlusion and maintained 5-HT concentration at a high level during reperfusion. Production of 5-HIAA in the early reperfusion was significantly suppressed by decynium-22. These results indicate that PMAT and SERT independently regulate basal level of interstitial 5-HT, and PMAT plays a more important role in the clearance of 5-HT during reperfusion. These data suggest the involvement of PMAT in the monoamine oxidase-dependent deleterious pathway in the heart.
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Affiliation(s)
- Takashi Sonobe
- Department of Cardiac PhysiologyNational Cerebral and Cardiovascular Center Research InstituteSuitaOsakaJapan
| | - Tsuyoshi Akiyama
- Department of Cardiac PhysiologyNational Cerebral and Cardiovascular Center Research InstituteSuitaOsakaJapan
| | - Cheng‐Kun Du
- Department of Cardiac PhysiologyNational Cerebral and Cardiovascular Center Research InstituteSuitaOsakaJapan
| | - James T. Pearson
- Department of Cardiac PhysiologyNational Cerebral and Cardiovascular Center Research InstituteSuitaOsakaJapan
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Abebe BT, Weiss M, Modess C, Tadken T, Wegner D, Meyer MJ, Schwantes U, Neumeister C, Scheuch E, Schulz HU, Tzvetkov M, Siegmund W. Pharmacokinetic Drug-Drug Interactions Between Trospium Chloride and Ranitidine Substrates of Organic Cation Transporters in Healthy Human Subjects. J Clin Pharmacol 2019; 60:312-323. [PMID: 31542894 DOI: 10.1002/jcph.1523] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 08/21/2019] [Indexed: 12/30/2022]
Abstract
Trospium chloride, a muscarinic receptor blocker, is poorly absorbed with different rates from areas in the jejunum and the cecum/ascending colon. To evaluate whether organic cation transporter (OCT) 1, OCT2 and multidrug and toxin extrusion (MATE) 1 and MATE2-K are involved in pharmacokinetics, competitions with ranitidine, a probe inhibitor of the cation transporters, were evaluated in transfected HEK293 cells. Furthermore, a drug interaction study with trospium chloride after intravenous (2 mg) and oral dosing (30 mg) plus ranitidine (300 mg) was performed in 12 healthy subjects and evaluated by noncompartmental analysis and population pharmacokinetic modeling. Ranitidine inhibited OCT1, OCT2, MATE1, and MATE2-K with half maximal inhibitory concentration values of 186 ± 25 µM, 482 ± 105 µM, 134 ± 37 µM, and 35 ± 11 µM, respectively. In contrast to our hypothesis, coadministration of ranitidine did not significantly decrease oral absorption of trospium. Instead, renal clearance was lowered by ∼15% (530 ± 99 vs 460 ± 120 mL/min; P < .05). It is possible that ranitidine was not available in competitive concentrations at the major colonic absorption site, as the inhibitor is absorbed in the small intestine and undergoes degradation by microbiota. The renal effects apparently result from inhibition of MATE1 and/or MATE2-K by ranitidine as predicted by in vitro to in vivo extrapolation. However, all pharmacokinetic changes were not of clinical relevance for the drug with highly variable pharmacokinetics. Intravenous trospium significantly lowered mean absorption time and relative bioavailability of ranitidine, which was most likely caused by muscarinic receptor blocking effects on intestinal motility and water turnover.
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Affiliation(s)
- Bayew Tsega Abebe
- Department of Pharmacology, Center of Drug Absorption and Transport (C_DAT), University Medicine of Greifswald, Greifswald, Germany
| | - Michael Weiss
- Department of Pharmacology, Martin Luther University Halle-Wittenberg, Germany
| | - Christiane Modess
- Department of Pharmacology, Center of Drug Absorption and Transport (C_DAT), University Medicine of Greifswald, Greifswald, Germany
| | - Tobias Tadken
- Department of Pharmacology, Center of Drug Absorption and Transport (C_DAT), University Medicine of Greifswald, Greifswald, Germany
| | - Danilo Wegner
- Department of Pharmacology, Center of Drug Absorption and Transport (C_DAT), University Medicine of Greifswald, Greifswald, Germany
| | - Marleen J Meyer
- Department of Pharmacology, Center of Drug Absorption and Transport (C_DAT), University Medicine of Greifswald, Greifswald, Germany
| | - Ulrich Schwantes
- Department Medical Science/Clinical Research, Dr. Pfleger Arzneimittel GmbH, Bamberg, Germany
| | - Claudia Neumeister
- Department Medical Science/Clinical Research, Dr. Pfleger Arzneimittel GmbH, Bamberg, Germany
| | - Eberhard Scheuch
- Department of Pharmacology, Center of Drug Absorption and Transport (C_DAT), University Medicine of Greifswald, Greifswald, Germany
| | - Hans-Ulrich Schulz
- LAFAA Laboratory for Contract Research in Clinical Pharmacology and Biopharmaceutical Analytics GmbH, Bad Schwartau, Germany
| | - Mladen Tzvetkov
- Department of Pharmacology, Center of Drug Absorption and Transport (C_DAT), University Medicine of Greifswald, Greifswald, Germany
| | - Werner Siegmund
- Department of Pharmacology, Center of Drug Absorption and Transport (C_DAT), University Medicine of Greifswald, Greifswald, Germany
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Bidirectional transport of 2-chloroadenosine by equilibrative nucleoside transporter 4 (hENT4): Evidence for allosteric kinetics at acidic pH. Sci Rep 2019; 9:13555. [PMID: 31537831 PMCID: PMC6753126 DOI: 10.1038/s41598-019-49929-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 09/02/2019] [Indexed: 01/23/2023] Open
Abstract
Adenosine has been reported to be transported by equilibrative nucleoside transporter 4 (ENT4), encoded by the SLC29A4 gene, in an acidic pH-dependent manner. This makes hENT4 of interest as a therapeutic target in acidic pathologies where adenosine is protective (e.g. vascular ischaemia). We examined the pH-sensitivity of nucleoside influx and efflux by hENT4 using a recombinant transfection model that lacks the confounding influences of other nucleoside transporters (PK15-NTD). We established that [3H]2-chloroadenosine, which is resistant to metabolism by adenosine deaminase, is a substrate for hENT4. Transport of [3H]2-chloroadenosine at a pH of 6.0 in PK15-NTD cells stably transfected with SLC29A4 was biphasic, with a low capacity (Vmax ~ 30 pmol/mg/min) high-affinity component (Km ~ 50 µM) apparent at low substrate concentrations, which shifted to a high capacity (Vmax ~ 500 pmol/mg/min) low affinity system (Km > 600 µM) displaying positive cooperativity at concentrations above 200 µM. Only the low affinity component was observed at a neutral pH of 7.5 (Km ~ 2 mM). Efflux of [3H]2-chloroadenosine from these cells was also enhanced by more than 4-fold at an acidic pH. Enhanced influx and efflux of nucleosides by hENT4 under acidic conditions supports its potential as a therapeutic target in pathologies such as ischaemia-reperfusion injury.
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Nishimura T, Sano Y, Takahashi Y, Noguchi S, Uchida Y, Takagi A, Tanaka T, Katakura S, Nakashima E, Tachikawa M, Maruyama T, Terasaki T, Tomi M. Quantification of ENT1 and ENT2 Proteins at the Placental Barrier and Contribution of These Transporters to Ribavirin Uptake. J Pharm Sci 2019; 108:3917-3922. [PMID: 31520644 DOI: 10.1016/j.xphs.2019.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 09/02/2019] [Accepted: 09/06/2019] [Indexed: 12/28/2022]
Abstract
The aims of this study are to quantify the protein levels of nucleoside transporters in placental microvillous membranes (MVMs) and to clarify the contributions of these transporters to ribavirin uptake at the placental barrier. Placental MVMs of human and rat expressed equilibrative nucleoside transporter (ENT) 1 protein, whereas the expression of ENT2 protein was obscure. Maternal-to-fetal transfer of [3H]ribavirin in rats was much higher than that of [14C]sucrose. The uptake of [3H]ribavirin by rat placental trophoblast TR-TBT 18 d-1 cells, which functionally express both ENT1 and ENT2 proteins, was saturable, and was significantly inhibited by 0.1 μM nitrobenzylthioinosine, which selectively abolishes ENT1-mediated uptake. Dipyridamole at 10 μM is capable of inhibiting ENT2 as well as ENT1, but a degree of inhibition by 10 μM dipyridamole on [3H]ribavirin uptake was not much different from that by 0.1 μM nitrobenzylthioinosine (ENT1-specific inhibitor). Therefore, ENT2 may contribute little to [3H]ribavirin uptake by these cells. Rat ENT1 cRNA-injected oocytes showed increased [3H]ribavirin uptake compared with water-injected oocytes, while rat ENT2 cRNA-injected oocytes did not. In conclusion, ENT1 protein expressed in placental MVMs appears to play a predominant role in the uptake of ribavirin.
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Affiliation(s)
- Tomohiro Nishimura
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo 105-8512, Japan
| | - Yuichiro Sano
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo 105-8512, Japan
| | - Yu Takahashi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo 105-8512, Japan
| | - Saki Noguchi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo 105-8512, Japan
| | - Yasuo Uchida
- Division of Membrane Transport and Drug Targeting, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Akinori Takagi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo 105-8512, Japan; Laboratory of Applied Therapeutics, Center for Education and Research on Clinical Pharmacy, Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan
| | - Takahiro Tanaka
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo 105-8512, Japan
| | - Satomi Katakura
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Emi Nakashima
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo 105-8512, Japan
| | - Masanori Tachikawa
- Division of Membrane Transport and Drug Targeting, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Tetsuo Maruyama
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Tetsuya Terasaki
- Division of Membrane Transport and Drug Targeting, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Masatoshi Tomi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo 105-8512, Japan.
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Sardoiwala MN, Srivastava AK, Kaundal B, Karmakar S, Choudhury SR. Recuperative effect of metformin loaded polydopamine nanoformulation promoting EZH2 mediated proteasomal degradation of phospho-α-synuclein in Parkinson's disease model. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2019; 24:102088. [PMID: 31476446 DOI: 10.1016/j.nano.2019.102088] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 08/06/2019] [Accepted: 08/19/2019] [Indexed: 12/16/2022]
Abstract
Posttranslational modification and agglomeration of α-synuclein (α-Syn), mitochondrial dysfunction, oxidative stress and loss of dopaminergic neurons are hallmark of Parkinson's disease (PD). This paper evaluates neuroprotection efficacy of nature inspired biocompatible polydopamine nanocarrier for metformin delivery (Met encapsulated PDANPs) by crossing blood brain barrier in in vitro, 3D and in vivo experimental PD models. The neuroprotective potential was arbitrated by downregulation of phospho-serine 129 (pSer129) α-Syn, with reduction in oxidative stress, prevention of apoptosis and anti-inflammatory activities. The neuroprotective mechanism proved novel interaction of epigenetic regulator EZH2 mediated ubiquitination and proteasomal degradation of aggregated pSer129 α-Syn. In summary, this study divulges the neuroprotective role of Met loaded PDANPs by reversing the neurochemical deficits by confirming an epigenetic mediated nanotherapeutic approach for the PD prevention.
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Affiliation(s)
| | - Anup K Srivastava
- Institute of Nano Science and Technology, Habitat Centre, Mohali, Punjab, India
| | - Babita Kaundal
- Institute of Nano Science and Technology, Habitat Centre, Mohali, Punjab, India
| | - Surajit Karmakar
- Institute of Nano Science and Technology, Habitat Centre, Mohali, Punjab, India.
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Markowicz-Piasecka M, Huttunen J, Sikora J, Huttunen KM. Sulfenamide derivatives can improve transporter-mediated cellular uptake of metformin and induce cytotoxicity in human breast adenocarcinoma cell lines. Bioorg Chem 2019; 87:321-334. [PMID: 30913467 DOI: 10.1016/j.bioorg.2019.03.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/05/2019] [Accepted: 03/14/2019] [Indexed: 12/14/2022]
Abstract
Metformin, the most frequently administered oral anti-diabetic drug, is a substrate for organic cation transporters (OCTs). This determines not only its pharmacokinetic properties but also its biochemical effects in humans, including its recently-discovered antiproliferative properties. The aim of the study was to verify the hypothesis whether chemical modification of its biguanide backbone may increase the cellular uptake and antiproliferative efficacy of metformin. The study examines five sulfenamide derivatives of metformin with differing lengths of alkyl chains. It determines their cellular uptake and the role of OCTs in their transport in human breast adenocarcinoma cells (epithelial-like MCF-7, and MDA-MB-231). It also evaluates whether increased cellular uptake of metformin derivatives is associated with their cytotoxic properties. Sulfenamide derivatives were characterized by a greater ability to bind to OCTs than metformin. Compound 2 with n-octyl alkyl chain was found to possess the greatest affinity towards OCTs, as measured by determination of [14C]choline uptake inhibition (IC50 = 236.1 ± 1.28 μmol/L, and 217.4 ± 1.33 μmol/L, for MCF-7 and MDA-MB-231 respectively). Sulfenamides were also found to exhibit better cellular uptake in comparison with the parent drug, metformin. For instance, the uptake of cyclohexyl derivative 1 was 1.28 ± 0.19 nmol/min/mg of proteins and thus was 12-fold higher than the metformin in MCF-7 cells. Furthermore, higher uptake was associated with the greatest antiproliferative properties expressed as the lowest IC50 value i.e. inhibiting the growth of 50% of the cells (IC50 = 0.72 ± 1.31 μmol/L). Collectively, chemical modification of metformin into sulfenamides with different alkyl substituents obtains better substrates for OCTs, and subsequently higher cellular uptake in MCF-7 and MDA-MB-231 cells. Additionally, the length of alkyl chain introduced to the sulfenamides was found to influence selectivity and transport efficiency via OCT1 compared to other possible transporters, as well as potential intracellular activity and cytotoxicity.
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Affiliation(s)
- Magdalena Markowicz-Piasecka
- Laboratory of Bioanalysis, Department of Pharmaceutical Chemistry, Drug Analysis and Radiopharmacy, Medical University of Lodz, ul. Muszyńskiego1, 90-151 Lodz, Poland.
| | - Johanna Huttunen
- School Of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1C, POB 1627, 70211 Kuopio, Finland
| | - Joanna Sikora
- Laboratory of Bioanalysis, Department of Pharmaceutical Chemistry, Drug Analysis and Radiopharmacy, Medical University of Lodz, ul. Muszyńskiego1, 90-151 Lodz, Poland
| | - Kristiina M Huttunen
- School Of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1C, POB 1627, 70211 Kuopio, Finland.
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42
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Zhu S, Lei S, Zhou S, Jin L, Zeng S, Jiang H, Zhou H. Luteolin shows antidepressant-like effect by inhibiting and downregulating plasma membrane monoamine transporter (PMAT, Slc29a4). J Funct Foods 2019. [DOI: 10.1016/j.jff.2019.01.048] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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43
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Bowman MA, Daws LC. Targeting Serotonin Transporters in the Treatment of Juvenile and Adolescent Depression. Front Neurosci 2019; 13:156. [PMID: 30872996 PMCID: PMC6401641 DOI: 10.3389/fnins.2019.00156] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Accepted: 02/11/2019] [Indexed: 01/01/2023] Open
Abstract
Depression is a serious public health concern. Many patients are not effectively treated, but in children and adolescents this problem is compounded by limited pharmaceutical options. Currently, the Food and Drug Administration approves only two antidepressants for use in these young populations. Both are selective serotonin reuptake inhibitors (SSRIs). Compounding matters further, they are therapeutically less efficacious in children and adolescents than in adults. Here, we review clinical and preclinical literature describing the antidepressant efficacy of SSRIs in juveniles and adolescents. Since the high-affinity serotonin transporter (SERT) is the primary target of SSRIs, we then synthesize these reports with studies of SERT expression/function during juvenile and adolescent periods. Preclinical literature reveals some striking parallels with clinical studies, primary among them is that, like humans, juvenile and adolescent rodents show reduced antidepressant-like responses to SSRIs. These findings underscore the utility of preclinical assays designed to screen drugs for antidepressant efficacy across ages. There is general agreement that SERT expression/function is lower in juveniles and adolescents than in adults. It is well established that chronic SSRI treatment decreases SERT expression/function in adults, but strikingly, SERT expression/function in adolescents is increased following chronic treatment with SSRIs. Finally, we discuss a putative role for organic cation transporters and/or plasma membrane monoamine transporter in serotonergic homeostasis in juveniles and adolescents. Taken together, fundamental differences in SERT, and putatively in other transporters capable of serotonin clearance, may provide a mechanistic basis for the relative inefficiency of SSRIs to treat pediatric depression, relative to adults.
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Affiliation(s)
- Melodi A Bowman
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Lynette C Daws
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.,Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
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Xue Y, Ma C, Hanna I, Pan G. Intestinal Transporter-Associated Drug Absorption and Toxicity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1141:361-405. [DOI: 10.1007/978-981-13-7647-4_8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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45
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Electrophysiological Characterization of Novel Effects of the Uptake-2 Blocker Decynium-22 (D-22) on Dopaminergic Neurons in the Substantia Nigra Pars Compacta. Neuroscience 2019; 396:154-165. [PMID: 30447392 DOI: 10.1016/j.neuroscience.2018.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/23/2018] [Accepted: 11/07/2018] [Indexed: 01/11/2023]
Abstract
Extracellular levels of dopamine (DA) and other monoamines in the brain depend not only on the classic transporters encoded by SLC6A gene family such as DAT, NET and SERT, but also a more recently identified group of low-affinity/high-capacity 'Uptake-2' transporters, mainly OCT3 and PMAT. The most frequently used pharmacological tool in functional studies of Uptake-2 is decynium-22 (D-22) known to block these transporters. However, the effectiveness of this drug in enhancing extracellular DA remains uncertain. Our aim was to test the hypothesis that D-22 increases extracellular levels of DA released from the somatodendritic region of dopaminergic neurons in the substantia nigra pars compacta (SNc) by reducing the OCT3/PMAT-dependent component of DA uptake. Extracellular DA was assessed indirectly, by evoking D2-IPSCs in SNc neurons following stimulated release of this neurotransmitter in midbrain slices obtained from mice. Recordings were conducted after partial inhibition of DAT with nomifensine, and after application of L-DOPA which increased the releasable DA pool. Contrary to our expectations, D-22 reduced, rather than increased, the amplitude of D2-IPSCs. Other effects included inhibition of GABAB-IPSCs and Ih current, and a reduction in firing frequency of nigral neurons. These results show that in addition to the previously known non-specific inhibitory action on α1 adrenoceptors, D-22 exerts additional off-target effects by inhibiting dopaminergic and GABAergic synaptic transmission in the SNc and the spontaneous (pacemaker) activity of nigral neurons. It remains to be established if these novel effects contribute to a reduction in spontaneous locomotor activity reported in previous studies after systemic drug administration.
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46
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Costiniti V, Spera I, Menabò R, Palmieri EM, Menga A, Scarcia P, Porcelli V, Gissi R, Castegna A, Canton M. Monoamine oxidase-dependent histamine catabolism accounts for post-ischemic cardiac redox imbalance and injury. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3050-3059. [DOI: 10.1016/j.bbadis.2018.06.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 05/25/2018] [Accepted: 06/20/2018] [Indexed: 12/11/2022]
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Tsesmetzis N, Paulin CBJ, Rudd SG, Herold N. Nucleobase and Nucleoside Analogues: Resistance and Re-Sensitisation at the Level of Pharmacokinetics, Pharmacodynamics and Metabolism. Cancers (Basel) 2018; 10:cancers10070240. [PMID: 30041457 PMCID: PMC6071274 DOI: 10.3390/cancers10070240] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 07/18/2018] [Accepted: 07/20/2018] [Indexed: 02/07/2023] Open
Abstract
Antimetabolites, in particular nucleobase and nucleoside analogues, are cytotoxic drugs that, starting from the small field of paediatric oncology, in combination with other chemotherapeutics, have revolutionised clinical oncology and transformed cancer into a curable disease. However, even though combination chemotherapy, together with radiation, surgery and immunotherapy, can nowadays cure almost all types of cancer, we still fail to achieve this for a substantial proportion of patients. The understanding of differences in metabolism, pharmacokinetics, pharmacodynamics, and tumour biology between patients that can be cured and patients that cannot, builds the scientific basis for rational therapy improvements. Here, we summarise current knowledge of how tumour-specific and patient-specific factors can dictate resistance to nucleobase/nucleoside analogues, and which strategies of re-sensitisation exist. We revisit well-established hurdles to treatment efficacy, like the blood-brain barrier and reduced deoxycytidine kinase activity, but will also discuss the role of novel resistance factors, such as SAMHD1. A comprehensive appreciation of the complex mechanisms that underpin the failure of chemotherapy will hopefully inform future strategies of personalised medicine.
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Affiliation(s)
- Nikolaos Tsesmetzis
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, 171 77 Stockholm, Sweden.
| | - Cynthia B J Paulin
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden.
| | - Sean G Rudd
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden.
| | - Nikolas Herold
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, 171 77 Stockholm, Sweden.
- Paediatric Oncology, Theme of Children's and Women's Health, Karolinska University Hospital Solna, 171 76 Stockholm, Sweden.
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48
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Dickens D, Rädisch S, Chiduza GN, Giannoudis A, Cross MJ, Malik H, Schaeffeler E, Sison-Young RL, Wilkinson EL, Goldring CE, Schwab M, Pirmohamed M, Nies AT. Cellular Uptake of the Atypical Antipsychotic Clozapine Is a Carrier-Mediated Process. Mol Pharm 2018; 15:3557-3572. [PMID: 29944835 DOI: 10.1021/acs.molpharmaceut.8b00547] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The weak base antipsychotic clozapine is the most effective medication for treating refractory schizophrenia. The brain-to-plasma concentration of unbound clozapine is greater than unity, indicating transporter-mediated uptake, which has been insufficiently studied. This is important, because it could have a significant impact on clozapine's efficacy, drug-drug interaction, and safety profile. A major limitation of clozapine's use is the risk of clozapine-induced agranulocytosis/granulocytopenia (CIAG), which is a rare but severe hematological adverse drug reaction. We first studied the uptake of clozapine into human brain endothelial cells (hCMEC/D3). Clozapine uptake into cells was consistent with a carrier-mediated process, which was time-dependent and saturable ( Vmax = 3299 pmol/million cells/min, Km = 35.9 μM). The chemical inhibitors lamotrigine, quetiapine, olanzapine, prazosin, verapamil, indatraline, and chlorpromazine reduced the uptake of clozapine by up to 95%. This could in part explain the in vivo interactions observed in rodents or humans for these compounds. An extensive set of studies utilizing transporter-overexpressing cell lines and siRNA-mediated transporter knockdown in hCMEC/D3 cells showed that clozapine was not a substrate of OCT1 (SLC22A1), OCT3 (SLC22A3), OCTN1 (SLC22A4), OCTN2 (SLC22A5), ENT1 (SLC29A1), ENT2 (SLC29A2), and ENT4/PMAT (SLC29A4). In a recent genome-wide analysis, the hepatic uptake transporters SLCO1B1 (OATP1B1) and SLCO1B3 (OATP1B3) were identified as additional candidate transporters. We therefore also investigated clozapine transport into OATP1B-transfected cells and found that clozapine was neither a substrate nor an inhibitor of OATP1B1 and OATP1B3. In summary, we have identified a carrier-mediated process for clozapine uptake into brain, which may be partly responsible for clozapine's high unbound accumulation in the brain and its drug-drug interaction profile. Cellular clozapine uptake is independent from currently known drug transporters, and thus, molecular identification of the clozapine transporter will help to understand clozapine's efficacy and safety profile.
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Affiliation(s)
- David Dickens
- Department of Molecular and Clinical Pharmacology , University of Liverpool , Liverpool L69 3GL , U.K
| | - Steffen Rädisch
- Department of Molecular and Clinical Pharmacology , University of Liverpool , Liverpool L69 3GL , U.K
| | - George N Chiduza
- Department of Molecular and Clinical Pharmacology , University of Liverpool , Liverpool L69 3GL , U.K
| | - Athina Giannoudis
- Department of Molecular and Clinical Cancer Medicine , University of Liverpool , Liverpool L69 3BX , U.K
| | - Michael J Cross
- Department of Molecular and Clinical Pharmacology , University of Liverpool , Liverpool L69 3GL , U.K
| | - Hassan Malik
- Liverpool Hepatobiliary Unit , University Hospital Aintree , Liverpool L9 7AL , U.K
| | - Elke Schaeffeler
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology , 70376 Stuttgart , Germany.,University Tübingen , Tübingen , Germany
| | - Rowena L Sison-Young
- Department of Molecular and Clinical Pharmacology , University of Liverpool , Liverpool L69 3GL , U.K
| | - Emma L Wilkinson
- Department of Molecular and Clinical Pharmacology , University of Liverpool , Liverpool L69 3GL , U.K
| | - Christopher E Goldring
- Department of Molecular and Clinical Pharmacology , University of Liverpool , Liverpool L69 3GL , U.K
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology , 70376 Stuttgart , Germany.,Department of Clinical Pharmacology , University Hospital Tübingen , 72076 Tubingen , Germany.,Department of Pharmacy and Biochemistry , University Tübingen , 72076 Tübingen , Germany
| | - Munir Pirmohamed
- Department of Molecular and Clinical Pharmacology , University of Liverpool , Liverpool L69 3GL , U.K
| | - Anne T Nies
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology , 70376 Stuttgart , Germany.,University Tübingen , Tübingen , Germany
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49
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Clobenpropit, a histamine H 3 receptor antagonist/inverse agonist, inhibits [ 3 H]-dopamine uptake by human neuroblastoma SH-SY5Y cells and rat brain synaptosomes. Pharmacol Rep 2018; 70:146-155. [DOI: 10.1016/j.pharep.2017.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 08/12/2017] [Accepted: 08/22/2017] [Indexed: 12/19/2022]
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50
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Wimalasena K. Current Status, Gaps, and Weaknesses of the Mechanism of Selective Dopaminergic Toxicity of MPTP/MPP +. ADVANCES IN MOLECULAR TOXICOLOGY 2017. [DOI: 10.1016/b978-0-12-812522-9.00003-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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