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Bode A, Kowal M, Cannas Aghedu F, Kavanagh PS. SSRI use is not associated with the intensity of romantic love, obsessive thinking about a loved one, commitment, or sexual frequency in a sample of young adults experiencing romantic love. J Affect Disord 2025; 375:472-477. [PMID: 39848471 DOI: 10.1016/j.jad.2025.01.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 09/28/2024] [Accepted: 01/17/2025] [Indexed: 01/25/2025]
Abstract
For >15 years, researchers have speculated that selective serotonin reuptake inhibitor (SSRI) use is associated with negative romantic love outcomes. No one has empirically investigated this, however. Drawing on 810 participants from the Romantic Love Survey 2022, we used binary logistic regression to identify differences between young adults experiencing romantic love who were and were not taking SSRIs. Predictor variables were biological sex, mental health problems, intensity of romantic love, obsessive thinking about a loved one, commitment, and frequency of sex. Only biological sex and mental health problems were associated with SSRI use. None of our romantic love variables were associated with SSRI use. This is the first evidence to demonstrate that SSRI use is not associated with some features of romantic love in a sample of young adults experiencing romantic love. The findings have implications for clinical practice and can be used to allay some concerns among individuals considering commencing SSRIs for common mental health problems.
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Affiliation(s)
- Adam Bode
- School of Archaeology and Anthropology, The Australian National University, Canberra, ACT, Australia.
| | - Marta Kowal
- IDN Being Human Lab - Institute of Psychology, University of Wrocław, Wrocław, Poland
| | - Fabio Cannas Aghedu
- Emotions, Neurocognition and Therapeutic Behavioral Approaches (ENACT) Team, University of Nîmes, France
| | - Phillip S Kavanagh
- Discipline of Psychology, Faculty of Health, University of Canberra, Bruce, ACT, Australia; Justice and Society, University of South Australia, Magill, SA, Australia
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2
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Brown CR, Foster JD. Modulation of autism-associated serotonin transporters by palmitoylation: Insights into the molecular pathogenesis and targeted therapies for autism spectrum disorder. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.03.12.642908. [PMID: 40161745 PMCID: PMC11952500 DOI: 10.1101/2025.03.12.642908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 04/02/2025]
Abstract
Background Autism spectrum disorder (ASD) is a developmental disorder of the nervous system characterized by a deficiency in interpersonal communication skills, a pathologic tendency for repetitive behaviors, and highly restrictive interests. The spectrum is a gradient-based construct used to categorize the widely varying degrees of ASD phenotypes, and has been linked to a genetic etiology in 25% of cases. Prior studies have revealed that 30% of ASD patients exhibit hyperserotonemia, or elevated whole blood serotonin, implicating the serotonergic system in the pathogenesis of ASD. Likewise, escitalopram, a selective-serotonin reuptake inhibitor (SSRI), has been demonstrated to improve aberrant behavior and irritability in ASD patients, potentially by modulating abnormal brain activation. Prior studies have uncovered proband patients with rare mutations in the human serotonin transporter (hSERT) that manifest enhanced surface expression and transport capacity, suggesting that abnormal enhancement of hSERT function may be involved in the pathogenesis of ASD. Methods HEK-293 cells stably expressing WT, C109A, I425L, F465L, L550V, or K605N hSERT were subject to analysis for palmitoylation via Acyl-Biotin Exchange followed with hSERT immunoblotting. F465L functional enhancement was confirmed by surface analysis via biotinylation and saturation analysis via 5HT transport. F465L palmitoylation, surface expression and transport capacity were then assessed following treatment with 2-bromopalmitate or escitalopram. Results Here, we reveal that palmitoylation is enhanced in the ASD hSERT F465L and L550V coding variants, and confirm prior reports of enhanced kinetic activity and surface expression of F465L. Subsequently, treatment of F465L with the irreversible palmitoyl acyl-transferase inhibitor, 2-bromopalmitate (2BP), or escitalopram, rectified enhanced F465L palmitoylation, surface expression, and transport capacity to basal WT levels. Limitations Tests assessing L550V for surface expression, transport capacity, and reactivity to inhibition of palmitoylation was not assessed. In addition, further characterization is necessary for internalization rates, degradative mechanisms, the impact of cysteine-mediated substitutions, and other SSRIs on these processes. Conclusions Overall, our results implicate disordered hSERT palmitoylation in the pathogenesis of serotonergic ASD subtypes, with basal recovery of these processes following escitalopram providing insight into its molecular utility as an ASD therapeutic.
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Affiliation(s)
- Christopher R. Brown
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202-9037
| | - James D. Foster
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202-9037
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3
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Prange S, Metereau E, Klinger H, Huddlestone M, De Oliveira M, Duperrier S, Courault P, Redoute J, Tremblay L, Sgambato V, Lancelot S, Thobois S. Serotonergic dysfunction in patients with impulse control disorders in Parkinson's disease. Brain 2025:awaf087. [PMID: 40042882 DOI: 10.1093/brain/awaf087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2024] [Revised: 01/05/2025] [Accepted: 02/16/2025] [Indexed: 05/14/2025] Open
Abstract
Impulse control disorders (ICDs) are frequent and particularly distressing neuropsychiatric symptoms in patients with Parkinson's disease (PD) which are related to impaired behavioural inhibition. Multiple PET imaging studies indicate that striatal dopaminergic abnormalities contribute to hyperdopaminergic functioning in PD patients with ICD (PDICD+) and to the dysregulation of the limbic fronto-striatal networks which are critical for reward-related decision impulsivity. However, the serotonergic system is central to response inhibition and plays a critical role in neuropsychiatric symptoms in PD, but its role remains undetermined in PDICD. We hypothesized that PDICD+ patients exhibit serotonergic dysfunction within the cortico-striato-pallido-thalamic circuits involved in the inhibitory control of behaviour and decided to investigate the pre- and post-synaptic serotonergic innervation using two highly-specific PET tracers for the serotonin transporter (SERT) using [11C]DASB and the 5-HT2A receptor using [18F]altanserin. In this prospective, case-control, double-tracer PET study, we recruited 15 PDICD+ patients, 15 PDICD- patients and 15 healthy controls, matched for age and sex, and compared the availability of [11C]DASB and [18F]altanserin using permutation-based analysis. PDICD+ patients had one (n=9) or multiple ICDs (n=6), consisting in hypersexuality (n=8), compulsive eating (n=6), compulsive shopping (n=5) and pathological gambling (n=4) and were characterized by greater choice impulsivity (impaired delay discounting for monetary rewards) and greater urgency with more severe depressive and anxious symptoms. We demonstrate that PDICD+ patients had greater [11C]DASB binding in the posterior putamen and pallidum in comparison to PDICD- patients, corresponding to relatively preserved presynaptic SERT availability within the subcortical sensorimotor network involved in response inhibition. In addition, cortical [18F]altanserin binding was greater in PDICD+ patients in the bilateral supplementary motor area, precentral gyrus and right dorsolateral prefrontal cortex, involving the sensorimotor and associative networks which regulate behavioural inhibition. Furthermore, we show that pre- and post-synaptic serotonergic dysfunction subserving action versus decision impulsivity in PD patients specifically followed the distinctive functional organization of the sensorimotor and associative fronto-striatal networks. Altogether, we demonstrate that serotonergic dysfunction related to ICDs in PD specifically involve the sensorimotor and associative cortico-striato-pallido-thalamic circuits involved in inhibitory control. Thus, serotonergic dysfunction contributes to the mechanisms related to the vulnerability and development of ICDs in PD patients, beyond the known dopaminergic abnormalities in the limbic fronto-striatal circuit.
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Affiliation(s)
- Stéphane Prange
- Univ Lyon, Lyon Neuroscience Research Center (CRNL), CNRS UMR 5292, INSERM U1028, F- 69675 Bron, France
- Hospices Civils de Lyon, Hôpital Neurologique Pierre Wertheimer, Service de Neurologie C, Centre Expert Parkinson NS-PARK/FCRIN network, F-69500 Bron, France
- Univ Lyon, Université Claude Bernard Lyon 1, Faculté de Médecine et de Maïeutique Lyon Sud Charles Mérieux, F-69600 Oullins, France
| | - Elise Metereau
- Univ Lyon, Lyon Neuroscience Research Center (CRNL), CNRS UMR 5292, INSERM U1028, F- 69675 Bron, France
- Hospices Civils de Lyon, Hôpital Neurologique Pierre Wertheimer, Service de Neurologie C, Centre Expert Parkinson NS-PARK/FCRIN network, F-69500 Bron, France
| | - Hélène Klinger
- Hospices Civils de Lyon, Hôpital Neurologique Pierre Wertheimer, Service de Neurologie C, Centre Expert Parkinson NS-PARK/FCRIN network, F-69500 Bron, France
| | - Marine Huddlestone
- Hospices Civils de Lyon, Hôpital Neurologique Pierre Wertheimer, Service de Neurologie C, Centre Expert Parkinson NS-PARK/FCRIN network, F-69500 Bron, France
| | - Melinda De Oliveira
- Hospices Civils de Lyon, Hôpital Neurologique Pierre Wertheimer, Service de Neurologie C, Centre Expert Parkinson NS-PARK/FCRIN network, F-69500 Bron, France
| | - Sandra Duperrier
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5284, INSERM U1314, MeLiS, F-69008 Lyon, France
| | - Pierre Courault
- Univ Lyon, Lyon Neuroscience Research Center (CRNL), CNRS UMR 5292, INSERM U1028, F- 69675 Bron, France
- Hospices Civils de Lyon (HCL), F-69002 Lyon, France
- CERMEP-Imaging platform, Groupement Hospitalier Est, F- 69677 Bron, France
| | - Jérôme Redoute
- Univ Lyon, Lyon Neuroscience Research Center (CRNL), CNRS UMR 5292, INSERM U1028, F- 69675 Bron, France
- CERMEP-Imaging platform, Groupement Hospitalier Est, F- 69677 Bron, France
| | - Léon Tremblay
- Univ Lyon, Institut des Sciences Cognitives Marc Jeannerod, CNRS UMR 5229, F- 69675 Bron, France
| | - Véronique Sgambato
- Univ Lyon, Institut des Sciences Cognitives Marc Jeannerod, CNRS UMR 5229, F- 69675 Bron, France
| | - Sophie Lancelot
- Univ Lyon, Lyon Neuroscience Research Center (CRNL), CNRS UMR 5292, INSERM U1028, F- 69675 Bron, France
- Hospices Civils de Lyon (HCL), F-69002 Lyon, France
- CERMEP-Imaging platform, Groupement Hospitalier Est, F- 69677 Bron, France
| | - Stéphane Thobois
- Univ Lyon, Lyon Neuroscience Research Center (CRNL), CNRS UMR 5292, INSERM U1028, F- 69675 Bron, France
- Hospices Civils de Lyon, Hôpital Neurologique Pierre Wertheimer, Service de Neurologie C, Centre Expert Parkinson NS-PARK/FCRIN network, F-69500 Bron, France
- Univ Lyon, Université Claude Bernard Lyon 1, Faculté de Médecine et de Maïeutique Lyon Sud Charles Mérieux, F-69600 Oullins, France
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Koban F, Freissmuth M. The cell cycle protein MAD2 facilitates endocytosis of the serotonin transporter in the neuronal soma. EMBO Rep 2023; 24:e53408. [PMID: 37530743 PMCID: PMC10561363 DOI: 10.15252/embr.202153408] [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: 06/09/2021] [Revised: 06/23/2023] [Accepted: 07/14/2023] [Indexed: 08/03/2023] Open
Abstract
Monoamine transporters retrieve serotonin (SERT), dopamine (DAT), and norepinephrine (NET) from the synaptic cleft. Transporter internalization contributes to the regulation of their surface expression. Clathrin-mediated endocytosis of plasma membrane proteins requires adaptor protein-2 (AP2), which recruits cargo to the nascent clathrin cage. However, the intracellular portions of monoamine transporters are devoid of a conventional AP2-binding site. Here, we identify a MAD2 (mitotic arrest deficient-2) interaction motif in the C-terminus of SERT, which binds the closed conformation of MAD2 and allows for the recruitment of two additional mitotic spindle assembly checkpoint (SAC) proteins, BubR1 and p31comet , and of AP2. We visualize MAD2, BubR1, and p31comet in dorsal raphe neurons, and depletion of MAD2 in primary serotonergic rat neurons decreases SERT endocytosis in the soma. Our findings do not only provide mechanistic insights into transporter internalization but also allow for rationalizing why SAC proteins are present in post-mitotic neurons.
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Affiliation(s)
- Florian Koban
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and PharmacologyMedical University of ViennaViennaAustria
| | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and PharmacologyMedical University of ViennaViennaAustria
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5
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Bruzzone SEP, Nasser A, Aripaka SS, Spies M, Ozenne B, Jensen PS, Knudsen GM, Frokjaer VG, Fisher PM. Genetic contributions to brain serotonin transporter levels in healthy adults. Sci Rep 2023; 13:16426. [PMID: 37777558 PMCID: PMC10542378 DOI: 10.1038/s41598-023-43690-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 09/27/2023] [Indexed: 10/02/2023] Open
Abstract
The serotonin transporter (5-HTT) critically shapes serotonin neurotransmission by regulating extracellular brain serotonin levels; it remains unclear to what extent 5-HTT levels in the human brain are genetically determined. Here we applied [11C]DASB positron emission tomography to image brain 5-HTT levels and evaluated associations with five common serotonin-related genetic variants that might indirectly regulate 5-HTT levels (BDNF rs6265, SLC6A4 5-HTTLPR, HTR1A rs6295, HTR2A rs7333412, and MAOA rs1137070) in 140 healthy volunteers. In addition, we explored whether these variants could predict in vivo 5-HTT levels using a five-fold cross-validation random forest framework. MAOA rs1137070 T-carriers showed significantly higher brain 5-HTT levels compared to C-homozygotes (2-11% across caudate, putamen, midbrain, thalamus, hippocampus, amygdala and neocortex). We did not observe significant associations for the HTR1A rs6295 and HTR2A rs7333412 genotypes. Our previously observed lower subcortical 5-HTT availability for rs6265 met-carriers remained in the presence of these additional variants. Despite this significant association, our prediction models showed that genotype moderately improved prediction of 5-HTT in caudate, but effects were not statistically significant after adjustment for multiple comparisons. Our observations provide additional evidence that serotonin-related genetic variants modulate adult human brain serotonin neurotransmission.
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Affiliation(s)
- Silvia Elisabetta Portis Bruzzone
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Arafat Nasser
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Sagar Sanjay Aripaka
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marie Spies
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Brice Ozenne
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Public Health, Section of Biostatistics, University of Copenhagen, Copenhagen, Denmark
| | - Peter Steen Jensen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Vibe Gedsoe Frokjaer
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Psychiatric Centre Copenhagen, Copenhagen, Denmark
| | - Patrick MacDonald Fisher
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
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6
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West AM, Holleran KM, Jones SR. Kappa Opioid Receptors Reduce Serotonin Uptake and Escitalopram Efficacy in the Mouse Substantia Nigra Pars Reticulata. Int J Mol Sci 2023; 24:2080. [PMID: 36768403 PMCID: PMC9916942 DOI: 10.3390/ijms24032080] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
The serotonin and kappa opioid receptor (KOR) systems are strongly implicated in disorders of negative affect, such as anxiety and depression. KORs expressed on axon terminals inhibit the release of neurotransmitters, including serotonin. The substantia nigra pars reticulata (SNr) is involved in regulating affective behaviors. It receives the densest serotonergic innervation in the brain and has high KOR expression; however, the influence of KORs on serotonin transmission in this region is yet to be explored. Here, we used ex vivo fast-scan cyclic voltammetry (FSCV) to investigate the effects of a KOR agonist, U50, 488 (U50), and a selective serotonin reuptake inhibitor, escitalopram, on serotonin release and reuptake in the SNr. U50 alone reduced serotonin release and uptake, and escitalopram alone augmented serotonin release and slowed reuptake, while pretreatment with U50 blunted both the release and uptake effects of escitalopram. Here, we show that the KOR influences serotonin signaling in the SNr in multiple ways and short-term activation of the KOR alters serotonin responses to escitalopram. These interactions between KORs and serotonin may contribute to the complexity in the responses to treatments for disorders of negative affect. Ultimately, the KOR system may prove to be a promising pharmacological target, alongside traditional antidepressant treatments.
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Affiliation(s)
| | | | - Sara R. Jones
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Blvd, Winston Salem, NC 27157, USA
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7
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Lim J, Bang Y, Kim KM, Choi HJ. Differentiated HT22 cells as a novel model for in vitro screening of serotonin reuptake inhibitors. Front Pharmacol 2023; 13:1062650. [PMID: 36703746 PMCID: PMC9871236 DOI: 10.3389/fphar.2022.1062650] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 12/13/2022] [Indexed: 01/12/2023] Open
Abstract
The mouse hippocampal neuronal cell line HT22 is frequently used as an in vitro model to investigate the role of hippocampal cholinergic neurons in cognitive functions. HT22 cells are derived from hippocampal neuronal HT4 cells. However, whether these cells exhibit the serotonergic neuronal phenotype observed in mature hippocampal neurons has not been determined yet. In this present study, we examined whether the differentiation of HT22 cells enhances the serotonergic neuronal phenotype, and if so, whether it can be used for antidepressant screening. Our results show that differentiation of HT22 cells promoted neurite outgrowth and upregulation of N-methyl-D-aspartate receptor and choline acetyltransferase, which is similar to that observed in primary cultured hippocampal neurons. Furthermore, proteins required for serotonergic neurotransmission, such as tryptophan hydroxylase 2, serotonin (5-hydroxytryptamine, 5-HT)1a receptor, and serotonin transporter (SERT), were significantly upregulated in differentiated HT22 cells. The transcription factor Pet-1 was upregulated during HT22 differentiation and was responsible for the regulation of the serotonergic neuronal phenotype. Differentiation also enhanced the functional serotonergic properties of HT22 cells, as evidenced by increase in intracellular 5-HT levels, serotonin transporter SERT glycosylation, and 5-HT reuptake activity. The sensitivity of 5-HT reuptake inhibition by venlafaxine in differentiated HT22 cells (IC50, 27.21 nM) was comparable to that in HEK293 cells overexpressing serotonin transporter SERT (IC50, 30.65 nM). These findings suggest that the differentiation of HT22 cells enhances their functional serotonergic properties, and these cells could be a potential in vitro system for assessing the efficacy of antidepressant 5-HT reuptake inhibitors.
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Affiliation(s)
- Juhee Lim
- College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon, Gyeonggi-do, South Korea,College of Pharmacy and Research Institute of Pharmaceutical Sciences, Woosuk University, Wanju, Jeollabuk-do, South Korea
| | - Yeojin Bang
- College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon, Gyeonggi-do, South Korea
| | - Kyeong-Man Kim
- College of Pharmacy, Chonnam National University, Gwangju, South Korea
| | - Hyun Jin Choi
- College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon, Gyeonggi-do, South Korea,*Correspondence: Hyun Jin Choi,
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8
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González Delgado S, Garza-Veloz I, Trejo-Vazquez F, Martinez-Fierro ML. Interplay between Serotonin, Immune Response, and Intestinal Dysbiosis in Inflammatory Bowel Disease. Int J Mol Sci 2022; 23:ijms232415632. [PMID: 36555276 PMCID: PMC9779345 DOI: 10.3390/ijms232415632] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
Inflammatory Bowel Disease (IBD) is a chronic gastrointestinal disorder characterized by periods of activity and remission. IBD includes Crohn's disease (CD) and ulcerative colitis (UC), and even though IBD has not been considered as a heritable disease, there are genetic variants associated with increased risk for the disease. 5-Hydroxytriptamine (5-HT), or serotonin, exerts a wide range of gastrointestinal effects under both normal and pathological conditions. Furthermore, Serotonin Transporter (SERT) coded by Solute Carrier Family 6 Member 4 (SLC6A4) gene (located in the 17q11.1-q12 chromosome), possesses genetic variants, such as Serotonin Transporter Gene Variable Number Tandem Repeat in Intron 2 (STin2-VNTR) and Serotonin-Transporter-linked promoter region (5-HTTLPR), which have an influence over the functionality of SERT in the re-uptake and bioavailability of serotonin. The intestinal microbiota is a crucial actor in normal human gut physiology, exerting effects on serotonin, SERT function, and inflammatory processes. As a consequence of abnormal serotonin signaling and SERT function under these inflammatory processes, the use of selective serotonin re-uptake inhibitors (SSRIs) has been seen to improve disease activity and extraintestinal manifestations, such as depression and anxiety. The aim of this study is to integrate scientific data linking the intestinal microbiota as a regulator of gut serotonin signaling and re-uptake, as well as its role in the pathogenesis of IBD. We performed a narrative review, including a literature search in the PubMed database of both review and original articles (no date restriction), as well as information about the SLC6A4 gene and its genetic variants obtained from the Ensembl website. Scientific evidence from in vitro, in vivo, and clinical trials regarding the use of selective serotonin reuptake inhibitors as an adjuvant therapy in patients with IBD is also discussed. A total of 194 articles were used between reviews, in vivo, in vitro studies, and clinical trials.
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9
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Deo N, Redpath G. Serotonin Receptor and Transporter Endocytosis Is an Important Factor in the Cellular Basis of Depression and Anxiety. Front Cell Neurosci 2022; 15:804592. [PMID: 35280519 PMCID: PMC8912961 DOI: 10.3389/fncel.2021.804592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/16/2021] [Indexed: 11/13/2022] Open
Abstract
Depression and anxiety are common, debilitating psychiatric conditions affecting millions of people throughout the world. Current treatments revolve around selective serotonin reuptake inhibitors (SSRIs), yet these drugs are only moderately effective at relieving depression. Moreover, up to 30% of sufferers are SSRI non-responders. Endocytosis, the process by which plasma membrane and extracellular constituents are internalized into the cell, plays a central role in the regulation of serotonin (5-hydroxytryptophan, 5-HT) signaling, SSRI function and depression and anxiety pathogenesis. Despite their therapeutic potential, surprisingly little is known about the endocytosis of the serotonin receptors (5-HT receptors) or the serotonin transporter (SERT). A subset of 5-HT receptors are endocytosed by clathrin-mediated endocytosis following serotonin binding, while for the majority of 5-HT receptors the endocytic regulation is not known. SERT internalizes serotonin from the extracellular space into the cell to limit the availability of serotonin for receptor binding and signaling. Endocytosis of SERT reduces serotonin uptake, facilitating serotonin signaling. SSRIs predominantly inhibit SERT, preventing serotonin uptake to enhance 5-HT receptor signaling, while hallucinogenic compounds directly activate specific 5-HT receptors, altering their interaction with endocytic adaptor proteins to induce alternate signaling outcomes. Further, multiple polymorphisms and transcriptional/proteomic alterations have been linked to depression, anxiety, and SSRI non-response. In this review, we detail the endocytic regulation of 5-HT receptors and SERT and outline how SSRIs and hallucinogenic compounds modulate serotonin signaling through endocytosis. Finally, we will examine the deregulated proteomes in depression and anxiety and link these with 5-HT receptor and SERT endocytosis. Ultimately, in attempting to integrate the current studies on the cellular biology of depression and anxiety, we propose that endocytosis is an important factor in the cellular basis of depression and anxiety. We will highlight how a thorough understanding 5-HT receptor and SERT endocytosis is integral to understanding the biological basis of depression and anxiety, and to facilitate the development of a next generation of specific, efficacious antidepressant treatments.
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Affiliation(s)
- Nikita Deo
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Gregory Redpath
- European Molecular Biology Lab (EMBL) Australia Node in Single Molecule Science, School of Medical Sciences and the Australian Research Council (ARC) Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, NSW, Australia
- *Correspondence: Gregory Redpath
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Trézéguet V, Fatrouni H, Merched AJ. Immuno-Metabolic Modulation of Liver Oncogenesis by the Tryptophan Metabolism. Cells 2021; 10:cells10123469. [PMID: 34943977 PMCID: PMC8700200 DOI: 10.3390/cells10123469] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 11/25/2021] [Accepted: 12/01/2021] [Indexed: 01/06/2023] Open
Abstract
Metabolic rewiring in tumor cells is a major hallmark of oncogenesis. Some of the oncometabolites drive suppressive and tolerogenic signals from the immune system, which becomes complicit to the advent and the survival of neoplasia. Tryptophan (TRP) catabolism through the kynurenine (KYN) pathway was reported to play immunosuppressive actions across many types of cancer. Extensive debate of whether the culprit of immunosuppression was the depletion of TRP or rather KYN accumulation in the tumor microenvironment has been ongoing for years. Results from clinical trials assessing the benefit of inhibiting key limiting enzymes of this pathway such as indoleamine 2,3-dioxygenase (IDO1) or tryptophan 2,3-dioxygenase (TDO2) failed to meet the expectations. Bearing in mind the complexity of the tumoral terrain and the existence of different cancers with IDO1/TDO2 expressing and non-expressing tumoral cells, here we present a comprehensive analysis of the TRP global metabolic hub and the driving potential of the process of oncogenesis with the main focus on liver cancers.
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11
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Tomlinson ID, Kovtun O, Torres R, Bellocchio LG, Josephs T, Rosenthal SJ. A Novel Biotinylated Homotryptamine Derivative for Quantum Dot Imaging of Serotonin Transporter in Live Cells. Front Cell Neurosci 2021; 15:667044. [PMID: 34867196 PMCID: PMC8637195 DOI: 10.3389/fncel.2021.667044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 10/19/2021] [Indexed: 11/21/2022] Open
Abstract
The serotonin transporter (SERT) is the primary target for selective serotonin reuptake inhibitor (SSRI) antidepressants that are thought to exert their therapeutic effects by increasing the synaptic concentration of serotonin. Consequently, probes that can be utilized to study cellular trafficking of SERT are valuable research tools. We have developed a novel ligand (IDT785) that is composed of a SERT antagonist (a tetrahydro pyridyl indole derivative) conjugated to a biotinylated poly ethylene glycol (PEG) via a phenethyl linker. This compound was determined to be biologically active and inhibited SERT-mediated reuptake of IDT307 with the half-maximal inhibitory concentration of 7.2 ± 0.3 μM. We demonstrated that IDT785 enabled quantum dot (QD) labeling of membrane SERT in transfected HEK-293 cultures that could be blocked using the high affinity serotonin reuptake inhibitor paroxetine. Molecular docking studies suggested that IDT785 might be binding to the extracellular vestibule binding site rather than the orthosteric substrate binding site, which could be attributable to the hydrophilicity of the PEG chain and the increased loss of degrees of freedom that would be required to penetrate into the orthosteric binding site. Using IDT785, we were able to study the membrane localization and membrane dynamics of YFP-SERT heterologously expressed in HEK-293 cells and demonstrated that SERT expression was enriched in the membrane edge and in thin cellular protrusions.
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Affiliation(s)
- Ian D. Tomlinson
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Oleg Kovtun
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Ruben Torres
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States
| | | | - Travis Josephs
- Neuroscience Program, Vanderbilt University, Nashville, TN, United States
| | - Sandra J. Rosenthal
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Nashville, TN, United States
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12
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Bode A, Kushnick G. Proximate and Ultimate Perspectives on Romantic Love. Front Psychol 2021; 12:573123. [PMID: 33912094 PMCID: PMC8074860 DOI: 10.3389/fpsyg.2021.573123] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 03/12/2021] [Indexed: 12/20/2022] Open
Abstract
Romantic love is a phenomenon of immense interest to the general public as well as to scholars in several disciplines. It is known to be present in almost all human societies and has been studied from a number of perspectives. In this integrative review, we bring together what is known about romantic love using Tinbergen’s “four questions” framework originating from evolutionary biology. Under the first question, related to mechanisms, we show that it is caused by social, psychological mate choice, genetic, neural, and endocrine mechanisms. The mechanisms regulating psychopathology, cognitive biases, and animal models provide further insights into the mechanisms that regulate romantic love. Under the second question, related to development, we show that romantic love exists across the human lifespan in both sexes. We summarize what is known about its development and the internal and external factors that influence it. We consider cross-cultural perspectives and raise the issue of evolutionary mismatch. Under the third question, related to function, we discuss the fitness-relevant benefits and costs of romantic love with reference to mate choice, courtship, sex, and pair-bonding. We outline three possible selective pressures and contend that romantic love is a suite of adaptions and by-products. Under the fourth question, related to phylogeny, we summarize theories of romantic love’s evolutionary history and show that romantic love probably evolved in concert with pair-bonds in our recent ancestors. We describe the mammalian antecedents to romantic love and the contribution of genes and culture to the expression of modern romantic love. We advance four potential scenarios for the evolution of romantic love. We conclude by summarizing what Tinbergen’s four questions tell us, highlighting outstanding questions as avenues of potential future research, and suggesting a novel ethologically informed working definition to accommodate the multi-faceted understanding of romantic love advanced in this review.
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Affiliation(s)
- Adam Bode
- Human Behavioural Ecology Research Group, School of Archaeology and Anthropology, ANU College of Arts and Social Sciences, The Australian National University, Canberra, ACT, Australia
| | - Geoff Kushnick
- Human Behavioural Ecology Research Group, School of Archaeology and Anthropology, ANU College of Arts and Social Sciences, The Australian National University, Canberra, ACT, Australia
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13
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Gopaldas M, Zanderigo F, Zhan S, Ogden RT, Miller JM, Rubin-Falcone H, Cooper TB, Oquendo MA, Sullivan G, Mann JJ, Sublette ME. Brain serotonin transporter binding, plasma arachidonic acid and depression severity: A positron emission tomography study of major depression. J Affect Disord 2019; 257:495-503. [PMID: 31319341 PMCID: PMC6886679 DOI: 10.1016/j.jad.2019.07.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 06/11/2019] [Accepted: 07/04/2019] [Indexed: 11/17/2022]
Abstract
BACKGROUND Serotonin transporter (5-HTT) binding and polyunsaturated fatty acids (PUFAs) are implicated in major depressive disorder (MDD). Links between the two systems in animal models have not been investigated in humans. METHODS Using positron emission tomography (PET) and [11C]DASB, we studied relationships between 5-HTT binding potential and plasma levels of PUFAs docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (AA) in medication-free MDD patients (n = 21). PUFAs were quantified using transesterification and gas chromatography. Binding potential BPP, and alternative outcome measures BPF and BPND, were determined for [11C]DASB in six a priori brain regions of interest (ROIs) using likelihood estimation in graphical analysis (LEGA) to calculate radioligand total distribution volume (VT), and a validated hybrid deconvolution approach (HYDECA) that estimates radioligand non-displaceable distribution volume (VND) without a reference region. Linear mixed models used PUFA levels as predictors and binding potential measures as outcomes across the specified ROIs; age and sex as fixed effects; and subject as random effect to account for across-region binding correlations. As nonlinear relationships were observed, a quadratic term was added to final models. RESULTS AA predicted both 5-HTT BPP and depression severity nonlinearly, described by an inverted U-shaped curve. 5-HTT binding potential mediated the relationship between AA and depression severity. LIMITATIONS Given the small sample and multiple comparisons, results require replication. CONCLUSIONS Our findings suggest that AA status may impact depression pathophysiology through effects on serotonin transport. Future studies should examine whether these relationships explain therapeutic effects of PUFAs in the treatment of MDD.
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Affiliation(s)
- Manesh Gopaldas
- Department of Psychiatry, Columbia University, New York, NY, USA,Molecular Imaging & Neuropathology Area, New York State Psychiatric Institute, New York, NY, USA,Department of Psychiatry & Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN
| | - Francesca Zanderigo
- Department of Psychiatry, Columbia University, New York, NY, USA,Molecular Imaging & Neuropathology Area, New York State Psychiatric Institute, New York, NY, USA
| | - Serena Zhan
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY
| | - R. Todd Ogden
- Department of Psychiatry, Columbia University, New York, NY, USA,Molecular Imaging & Neuropathology Area, New York State Psychiatric Institute, New York, NY, USA,Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY
| | - Jeffrey M. Miller
- Department of Psychiatry, Columbia University, New York, NY, USA,Molecular Imaging & Neuropathology Area, New York State Psychiatric Institute, New York, NY, USA
| | - Harry Rubin-Falcone
- Department of Psychiatry, Columbia University, New York, NY, USA,Molecular Imaging & Neuropathology Area, New York State Psychiatric Institute, New York, NY, USA
| | - Thomas B. Cooper
- Department of Psychiatry, Columbia University, New York, NY, USA,Molecular Imaging & Neuropathology Area, New York State Psychiatric Institute, New York, NY, USA,Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Maria A. Oquendo
- Psychiatry Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - J. John Mann
- Department of Psychiatry, Columbia University, New York, NY, USA,Molecular Imaging & Neuropathology Area, New York State Psychiatric Institute, New York, NY, USA,Department of Radiology, Columbia University, New York, NY, USA
| | - M. Elizabeth Sublette
- Department of Psychiatry, Columbia University, New York, NY, USA,Molecular Imaging & Neuropathology Area, New York State Psychiatric Institute, New York, NY, USA,To whom correspondence should be addressed: New York State Psychiatric Institute, 1051 Riverside Drive, Unit 42, New York, NY 10032, Tel: 646 774-7514, Fax: 646 774-7589,
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14
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Saponara E, Visentin M, Baschieri F, Seleznik G, Martinelli P, Esposito I, Buschmann J, Chen R, Parrotta R, Borgeaud N, Bombardo M, Malagola E, Caflisch A, Farhan H, Graf R, Sonda S. Serotonin uptake is required for Rac1 activation in Kras-induced acinar-to-ductal metaplasia in the pancreas. J Pathol 2018; 246:352-365. [PMID: 30058725 DOI: 10.1002/path.5147] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 07/03/2018] [Accepted: 07/26/2018] [Indexed: 02/06/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDAC), which is the primary cause of pancreatic cancer mortality, is poorly responsive to currently available interventions. Identifying new targets that drive PDAC formation and progression is critical for developing alternative therapeutic strategies to treat this lethal malignancy. Using genetic and pharmacological approaches, we investigated in vivo and in vitro whether uptake of the monoamine serotonin [5-hydroxytryptamine (5-HT)] is required for PDAC development. We demonstrated that pancreatic acinar cells have the ability to readily take up 5-HT in a transport-mediated manner. 5-HT uptake promoted activation of the small GTPase Ras-related C3 botulinum toxin substrate 1 (Rac1), which is required for transdifferentiation of acinar cells into acinar-to-ductal metaplasia (ADM), a key determinant in PDAC development. Consistent with the central role played by Rac1 in ADM formation, inhibition of the 5-HT transporter Sert (Slc6a4) with fluoxetine reduced ADM formation both in vitro and in vivo in a cell-autonomous manner. In addition, fluoxetine treatment profoundly compromised the stromal reaction and affected the proliferation and lipid metabolism of malignant PDAC cells. We propose that Sert is a promising therapeutic target to counteract the early event of ADM, with the potential to stall the initiation and progression of pancreatic carcinogenesis. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Enrica Saponara
- Department of Visceral and Transplant Surgery, University Hospital of Zurich, Zurich, Switzerland
| | - Michele Visentin
- Department of Clinical Pharmacology and Toxicology, University Hospital of Zurich, Zurich, Switzerland
| | - Francesco Baschieri
- Institute Gustave Roussy, Institut National de la Santé et de la Recherche Médicale (INSERM), Villejuif, France
| | - Gitta Seleznik
- Department of Visceral and Transplant Surgery, University Hospital of Zurich, Zurich, Switzerland
| | - Paola Martinelli
- Institute for Cancer Research, Medical University, Wien, Austria
| | - Irene Esposito
- Institut für Pathologie, University Hospital of Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany
| | - Johanna Buschmann
- Division of Plastic and Hand Surgery, University Hospital Zurich, Zurich, Switzerland
| | - Rong Chen
- Department of Visceral and Transplant Surgery, University Hospital of Zurich, Zurich, Switzerland
| | - Rossella Parrotta
- Laboratory of Molecular Oncology, Thorax und Lungen Tumor Zentrum, University Hospital of Zurich, Zurich, Switzerland
| | - Nathalie Borgeaud
- Department of Visceral and Transplant Surgery, University Hospital of Zurich, Zurich, Switzerland
| | - Marta Bombardo
- Department of Visceral and Transplant Surgery, University Hospital of Zurich, Zurich, Switzerland
| | - Ermanno Malagola
- Department of Visceral and Transplant Surgery, University Hospital of Zurich, Zurich, Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Hesso Farhan
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Rolf Graf
- Department of Visceral and Transplant Surgery, University Hospital of Zurich, Zurich, Switzerland.,Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Sabrina Sonda
- Department of Visceral and Transplant Surgery, University Hospital of Zurich, Zurich, Switzerland.,Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
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15
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Liu JJ, Hezghia A, Shaikh SR, Cenido JF, Stark RE, Mann JJ, Sublette ME. Regulation of monoamine transporters and receptors by lipid microdomains: implications for depression. Neuropsychopharmacology 2018; 43:2165-2179. [PMID: 30022062 PMCID: PMC6135777 DOI: 10.1038/s41386-018-0133-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 05/24/2018] [Accepted: 06/18/2018] [Indexed: 12/16/2022]
Abstract
Lipid microdomains ("rafts") are dynamic, nanoscale regions of the plasma membrane enriched in cholesterol and glycosphingolipids, that possess distinctive physicochemical properties including higher order than the surrounding membrane. Lipid microdomain integrity is thought to affect neurotransmitter signaling by regulating membrane-bound protein signaling. Among the proteins potentially affected are monoaminergic receptors and transporters. As dysfunction of monoaminergic neurotransmission is implicated in major depressive disorder and other neuropsychiatric conditions, interactions with lipid microdomains may be of clinical importance. This systematic review evaluates what is known about the molecular relationships of monoamine transporter and receptor regulation to lipid microdomains. The PubMed/MeSH database was searched for original studies published in English through August 2017 concerning relationships between lipid microdomains and serotonin, dopamine and norepinephrine transporters and receptors. Fifty-seven publications were identified and assessed. Strong evidence implicates lipid microdomains in the regulation of serotonin and norepinephrine transporters; serotonin 1A, 2A, 3A, and 7A receptors; and dopamine D1 and β2 adrenergic receptors. Results were conflicting or more complex regarding lipid microdomain associations with the dopamine transporter, D2, D3, and D5 receptors; and negative with respect to β1 adrenergic receptors. Indirect evidence suggests that antidepressants, lipid-lowering drugs, and polyunsaturated fatty acids may exert effects on depression and suicide by altering the lipid milieu, thereby affecting monoaminergic transporter and receptor signaling. The lipid composition of membrane subdomains is involved in localization and trafficking of specific monoaminergic receptors and transporters. Elucidating precise mechanisms whereby lipid microdomains modulate monoamine neurotransmission in clinical contexts can have critical implications for pharmacotherapeutic targeting.
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Affiliation(s)
- Joanne J Liu
- Department of Molecular Imaging & Neuropathology, New York State Psychiatric Institute, New York, NY, USA
- Chestnut Hill Hospital, Philadelphia, PA, USA
| | - Adrienne Hezghia
- Department of Molecular Imaging & Neuropathology, New York State Psychiatric Institute, New York, NY, USA
- Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Saame Raza Shaikh
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Joshua F Cenido
- Department of Molecular Imaging & Neuropathology, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Charles R. Drew University of Medicine and Science, Los Angeles, CA, USA
| | - Ruth E Stark
- Department of Chemistry and Biochemistry and CUNY Institute for Macromolecular Assemblies, The City College of New York, New York, NY, USA
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, USA
| | - J John Mann
- Department of Molecular Imaging & Neuropathology, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, USA
- Department of Radiology, Columbia University, New York, NY, USA
| | - M Elizabeth Sublette
- Department of Molecular Imaging & Neuropathology, New York State Psychiatric Institute, New York, NY, USA.
- Department of Psychiatry, Columbia University, New York, NY, USA.
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16
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Kliman HJ, Quaratella SB, Setaro AC, Siegman EC, Subha ZT, Tal R, Milano KM, Steck TL. Pathway of Maternal Serotonin to the Human Embryo and Fetus. Endocrinology 2018; 159:1609-1629. [PMID: 29381782 DOI: 10.1210/en.2017-03025] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/22/2017] [Indexed: 12/16/2022]
Abstract
Serotonin [5-hydroxytryptamine (5-HT)] is essential to intrauterine development, but its source is debated. We used immunocytochemistry to gauge 5-HT, its biosynthetic enzyme tryptophan hydroxylase 1 (TPH1); an importer (serotonin transporter, 5-HTT/SERT/SLC6A); other transporters [P-glycoprotein 1 (P-gp/ABCB1), OCT3/SLC22A3, and gap junction connexin-43]; and the 5-HT degradative enzyme monoamine oxidase A (MAOA) in sections of placentas. In humans, 5-HT was faintly stained only in first-trimester trophoblasts, whereas TPH1 was not seen at any stage. SERT was expressed in syncytiotrophoblasts and, more strongly, in cytotrophoblasts. MAOA was prominent in syncytiotrophoblasts, OCT3 and gap junctions were stained in cytotrophoblasts, and P-gp was present at the apical surfaces of both epithelia. 5-HT added to cultured placental explants accumulated in the trophoblast epithelium and reached the villus core vessels. Trophoblast uptake was blocked by the SERT inhibitor escitalopram. Inhibition of gap junctions with heptanol prevented the accumulation of 5-HT in cytotrophoblasts, whereas blocking OCT3 with decynium-22 and P-gp with mitotane led to its accumulation in cytotrophoblasts. Reducing 5-HT destruction by inhibiting MAOA with clorgyline increased the accumulation of 5-HT throughout the villus. In the mouse fetus, intravascular platelets stained prominently for 5-HT at day 13.5, whereas the placenta and yolk sac endoderm were both negative. TPH1 was not detected, but SERT was prominent in these mouse tissues. We conclude that serotonin is conveyed from the maternal blood stream through syncytiotrophoblasts, cytotrophoblasts and the villus core to the fetus through a physiological pathway that involves at least SERT, gap junctions, P-gp, OCT3, and MAOA.
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Affiliation(s)
- Harvey J Kliman
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut
| | | | | | | | | | - Reshef Tal
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut
| | - Kristin M Milano
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut
| | - Theodore L Steck
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois
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17
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D'Ascola A, Bruschetta G, Zanghì G, Campo S, Medica P, Campana S, Ferlazzo G, Gibbs BF, Ferlazzo AM. Changes in plasma 5-HT levels and equine leukocyte SERT expression in response to treadmill exercise. Res Vet Sci 2018. [PMID: 29518708 DOI: 10.1016/j.rvsc.2018.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Serotonin (5-HT) is a neurohormone transported from plasma into platelets and leukocytes by a specific transporter (SERT). While it is known that the brain 5-HT system is modulated by physical exercise, the peripheral serotoninergic response to exercise is not yet fully elucidated. In particular, this study aimed to evaluate changes in plasma 5-HT levels and equine leukocyte SERT expression in response to treadmill exercise in untrained horses. Analyses were carried out pre- and post-treadmill exercise. 5-HT plasma levels were analysed by HPLC. Leukocytes and platelets were isolated to perform Real Time PCR for the evaluation of SERT mRNA levels. Western blot was conducted for the detection of SERT protein levels. The presence of SERT in leukocytes was analysed by flow cytometry. The functionality of SERT on leukocytes was investigated by using paroxetine as inhibitor of 5-HT reuptake. Results showed a significant decrease in SERT levels after exercise in both leukocytes and platelets and a significant increase in plasma 5-HT levels. Flow cytometry revealed that SERT is functional in one specific horse leukocyte subpopulation, still not identified, and paroxetine was able to block 5-HT reuptake into leukocytes. The exercise may have induced an increased mobilization of free-tryptophan and a release of 5-HT from the stores in the blood. High concentrations of plasma 5-HT could have caused a reduction in SERT expression affecting cellular 5-HT storage/uptake. The increase of cortisol levels after treadmill exercise was not significant. Exercise modulates the peripheral serotonin metabolism. More research is needed to assess its physiological implications.
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Affiliation(s)
- Angela D'Ascola
- Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, Via Consolare Valeria 1, 98124 Messina, Italy.
| | - Giuseppe Bruschetta
- Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
| | - Gabriella Zanghì
- Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy
| | - Salvatore Campo
- Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, Via Consolare Valeria 1, 98124 Messina, Italy.
| | - Pietro Medica
- Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
| | - Stefania Campana
- Department of Human Pathology, University of Messina, Via Consolare Valeria 1, 98124 Messina, Italy
| | - Guido Ferlazzo
- Department of Human Pathology, University of Messina, Via Consolare Valeria 1, 98124 Messina, Italy.
| | - Bernhard F Gibbs
- Medway School of Pharmacy, University of Kent, ME4 4TB Chatham Maritime, United Kingdom.
| | - Alida Maria Ferlazzo
- Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
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18
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Oxytocin and Serotonin Brain Mechanisms in the Nonhuman Primate. J Neurosci 2017; 37:6741-6750. [PMID: 28607170 DOI: 10.1523/jneurosci.0659-17.2017] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 05/31/2017] [Accepted: 06/01/2017] [Indexed: 01/29/2023] Open
Abstract
Oxytocin (OT) is increasingly studied for its therapeutic potential in psychiatric disorders, which are associated with the deregulation of several neurotransmission systems. Studies in rodents demonstrated that the interaction between OT and serotonin (5-HT) is critical for several aspects of social behavior. Using PET scan in humans, we have recently found that 5-HT 1A receptor (5-HT1AR) function is modified after intranasal oxytocin intake. However, the underlying mechanism between OT and 5-HT remains unclear. To understand this interaction, we tested 3 male macaque monkeys using both [11C]DASB and [18F]MPPF, two PET radiotracers, marking the serotonin transporter and the 5-HT1AR, respectively. Oxytocin (1 IU in 20 μl of ACSF) or placebo was injected into the brain lateral ventricle 45 min before scans. Additionally, we performed postmortem autoradiography. Compared with placebo, OT significantly reduced [11C]DASB binding potential in right amygdala, insula, and hippocampus, whereas [18F]MPPF binding potential increased in right amygdala and insula. Autoradiography revealed that [11C]DASB was sensitive to physiological levels of 5-HT modification, and that OT does not act directly on the 5-HT1AR. Our results show that oxytocin administration in nonhuman primates influences serotoninergic neurotransmission via at least two ways: (1) by provoking a release of serotonin in key limbic regions; and (2) by increasing the availability of 5-HT1AR receptors in the same limbic areas. Because these two molecules are important for social behavior, our study sheds light on the specific nature of their interaction, therefore helping to develop new mechanisms-based therapies for psychiatric disorders.SIGNIFICANCE STATEMENT Social behavior is largely controlled by brain neuromodulators, such as oxytocin and serotonin. While these are currently targeted in the context of psychiatric disorders such as autism and schizophrenia, a new promising pharmaceutical strategy is to study the interaction between these systems. Here we depict the interplay between oxytocin and serotonin in the nonhuman primate brain. We found that oxytocin provokes the release of serotonin, which in turn impacts on the serotonin 1A receptor system, by modulating its availability. This happens in several key brain regions for social behavior, such as the amygdala and insula. This novel finding can open ways to advance treatments where drugs are combined to influence several neurotransmission networks.
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Oosting RS, Chan JS, Olivier B, Banerjee P, Choi YK, Tarazi F. Differential effects of vilazodone versus citalopram and paroxetine on sexual behaviors and serotonin transporter and receptors in male rats. Psychopharmacology (Berl) 2016; 233:1025-34. [PMID: 26758283 PMCID: PMC4759230 DOI: 10.1007/s00213-015-4198-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 12/04/2015] [Indexed: 12/23/2022]
Abstract
RATIONALE Sexual side effects are commonly associated with selective serotonin reuptake inhibitor (SSRI) treatment. Some evidence suggest that activation of 5-HT1A receptors attenuates SSRI-induced sexual dysfunction. OBJECTIVE This study in male rats compared the effects of vilazodone, an antidepressant with SSRI and 5-HT1A receptor partial agonist activity, with other prototypical SSRIs (citalopram and paroxetine) on sexual behaviors and 5-HT receptors (5-HT1A and 5-HT2A) and transporter (5-HTT) levels in select forebrain regions of the limbic system using quantitative autoradiography. METHODS Rats received vilazodone (1, 3, and 10 mg/kg), citalopram (10 and 30 mg/kg), or paroxetine (10 mg/kg) treatment for 14 days. Sexual behaviors (frequency and latency of mounts, intromissions, and ejaculations) were measured in the presence of an estrous female rat on days 1 (acute), 7 (subchronic), and 14 (chronic). RESULTS Vilazodone-treated rats exhibited no sexual dysfunction compared with controls; in contrast, the citalopram- and paroxetine-treated rats exhibited impaired copulatory and ejaculatory behaviors after subchronic and chronic treatments. Chronic vilazodone treatment markedly decreased 5-HT1A receptor levels in cortical and hippocampal regions, while the SSRIs increased levels of this receptor in similar regions. All chronic treatments reduced 5-HTT levels across the forebrain; however, the magnitude of the decrease was considerably smaller for vilazodone than for the SSRIs. CONCLUSIONS The current studies showed that chronic treatment with vilazodone, in contrast to citalopram and paroxetine, was not associated with diminished sexual behaviors in male rats, which may be related to the differential effects of vilazodone on 5-HT1A receptor and 5-HTT levels relative to conventional SSRIs.
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Affiliation(s)
- Ronald S Oosting
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands.
| | - Johnny S Chan
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Berend Olivier
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | | | - Yong Kee Choi
- Department of Psychiatry and Neuroscience Harvard Medical School and McLean Hospital, Belmont, MA, USA
| | - Frank Tarazi
- Department of Psychiatry and Neuroscience Harvard Medical School and McLean Hospital, Belmont, MA, USA
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Finnema SJ, Halldin C, Bang-Andersen B, Bundgaard C, Farde L. Serotonin transporter occupancy by escitalopram and citalopram in the non-human primate brain: a [(11)C]MADAM PET study. Psychopharmacology (Berl) 2015; 232:4159-67. [PMID: 25980484 DOI: 10.1007/s00213-015-3961-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/05/2015] [Indexed: 11/29/2022]
Abstract
RATIONALE A number of serotonin receptor positron emission tomography (PET) radioligands have been shown to be sensitive to changes in extracellular serotonin concentration, in a generalization of the well-known dopamine competition model. High doses of selective serotonin reuptake inhibitors (SSRIs) decrease serotonin receptor availability in monkey brain, consistent with increased serotonin concentrations. However, two recent studies on healthy human subjects, using a single, lower and clinically relevant SSRI dose, showed increased cortical serotonin receptor radioligand binding, suggesting potential decreases in serotonin concentration in projection regions when initiating treatment. OBJECTIVES The cross-species differential SSRI effect may be partly explained by serotonin transporter (SERT) occupancy in monkey brain being higher than is clinically relevant. We here determine SERT occupancy after single doses of escitalopram or citalopram by conducting PET measurements with [(11)C]MADAM in monkeys. Relationships between dose, plasma concentration and SERT occupancy were estimated by one-site binding analyses. Binding affinity was expressed as dose (ID50) or plasma concentration (K i) where 50 % SERT occupancy was achieved. RESULTS Estimated ID50 and K i values were 0.020 mg/kg and 9.6 nmol/L for escitalopram and 0.059 mg/kg and 9.7 nmol/L for citalopram, respectively. Obtained K i values are comparable to values reported in humans. CONCLUSIONS Escitalopram or citalopram doses nearly saturated SERT in previous monkey studies which examined serotonin sensitivity of receptor radioligands. PET-measured cross-species differential effects of SSRI on cortical serotonin concentration may thus be related to SSRI dose. Future monkey studies using SSRI doses inducing clinically relevant SERT occupancy may further illuminate the delayed onset of SSRI therapeutic effects.
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Affiliation(s)
- Sjoerd J Finnema
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Building R5:02, SE-17176, Stockholm, Sweden. .,Department of Diagnostic Radiology, Yale University, New Haven, CT, USA.
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Building R5:02, SE-17176, Stockholm, Sweden
| | | | | | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Building R5:02, SE-17176, Stockholm, Sweden.,AstraZeneca, Translational Science Center at Karolinska Institutet, Stockholm, Sweden
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Subramanian VS, Ghosal A, Kapadia R, Nabokina SM, Said HM. Molecular Mechanisms Mediating the Adaptive Regulation of Intestinal Riboflavin Uptake Process. PLoS One 2015; 10:e0131698. [PMID: 26121134 PMCID: PMC4484800 DOI: 10.1371/journal.pone.0131698] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/04/2015] [Indexed: 12/16/2022] Open
Abstract
The intestinal absorption process of vitamin B2 (riboflavin, RF) is carrier-mediated, and all three known human RF transporters, i.e., hRFVT-1, -2, and -3 (products of the SLC52A1, 2 & 3 genes, respectively) are expressed in the gut. We have previously shown that the intestinal RF uptake process is adaptively regulated by substrate level, but little is known about the molecular mechanism(s) involved. Using human intestinal epithelial NCM460 cells maintained under RF deficient and over-supplemented (OS) conditions, we now show that the induction in RF uptake in RF deficiency is associated with an increase in expression of the hRFVT-2 & -3 (but not hRFVT-1) at the protein and mRNA levels. Focusing on hRFVT-3, the predominant transporter in the intestine, we also observed an increase in the level of expression of its hnRNA and activity of its promoter in the RF deficiency state. An increase in the level of expression of the nuclear factor Sp1 (which is important for activity of the SLC52A3 promoter) was observed in RF deficiency, while mutating the Sp1/GC site in the SLC52A3 promoter drastically decreased the level of induction in SLC52A3 promoter activity in RF deficiency. We also observed specific epigenetic changes in the SLC52A3 promoter in RF deficiency. Finally, an increase in hRFVT-3 protein expression at the cell surface was observed in RF deficiency. Results of these investigations show, for the first time, that transcriptional and post-transcriptional mechanisms are involved in the adaptive regulation of intestinal RF uptake by the prevailing substrate level.
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Affiliation(s)
- Veedamali S. Subramanian
- Department of Medicine, University of California, Irvine, California, United States of America
- VAMC, Long Beach, California, United States of America
| | - Abhisek Ghosal
- Department of Medicine, University of California, Irvine, California, United States of America
- VAMC, Long Beach, California, United States of America
| | - Rubina Kapadia
- Department of Medicine, University of California, Irvine, California, United States of America
- VAMC, Long Beach, California, United States of America
| | - Svetlana M. Nabokina
- Department of Medicine, University of California, Irvine, California, United States of America
- VAMC, Long Beach, California, United States of America
| | - Hamid M. Said
- Department of Medicine, University of California, Irvine, California, United States of America
- Department of Physiology/Biophysics, University of California, Irvine, California, United States of America
- VAMC, Long Beach, California, United States of America
- * E-mail:
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