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Salerno JA, Rehen S. Human pluripotent stem cells as a translational toolkit in psychedelic research in vitro. iScience 2024; 27:109631. [PMID: 38628967 PMCID: PMC11019282 DOI: 10.1016/j.isci.2024.109631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2024] Open
Abstract
Psychedelics, recognized for their impact on perception, are resurging as promising treatments with rapid onset for mood and substance use disorders. Despite increasing evidence from clinical trials, questions persist about the cellular and molecular mechanisms and their precise correlation with treatment outcomes. Murine neurons and immortalized non-neural cell lines harboring overexpressed constructs have shed light on neuroplastic changes mediated by the serotonin 2A receptor (5-HT2AR) as the primary mechanism. However, limitations exist in capturing human- and disease-specific traits. Here, we discuss current accomplishments and prospects for incorporating human pluripotent stem cells (PSCs) to complement these models. PSCs can differentiate into various brain cell types, mirroring endogenous expression patterns and cell identities to recreate disease phenotypes. Brain organoids derived from PSCs resemble cell diversity and patterning, while region-specific organoids simulate circuit-level phenotypes. PSC-based models hold significant promise to illuminate the cellular and molecular substrates of psychedelic-induced phenotypic recovery in neuropsychiatric disorders.
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Affiliation(s)
- José Alexandre Salerno
- D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil
- Graduate Program in Morphological Sciences, Institute of Biomedical Sciences, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Department of Morphological Sciences, Biomedical Institute, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
| | - Stevens Rehen
- D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil
- Department of Genetics, Institute of Biology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Usona Institute, Fitchburg, WI, USA
- Promega Corporation, Madison, WI, USA
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Transition from Animal-Based to Human Induced Pluripotent Stem Cells (iPSCs)-Based Models of Neurodevelopmental Disorders: Opportunities and Challenges. Cells 2023; 12:cells12040538. [PMID: 36831205 PMCID: PMC9954744 DOI: 10.3390/cells12040538] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/25/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023] Open
Abstract
Neurodevelopmental disorders (NDDs) arise from the disruption of highly coordinated mechanisms underlying brain development, which results in impaired sensory, motor and/or cognitive functions. Although rodent models have offered very relevant insights to the field, the translation of findings to clinics, particularly regarding therapeutic approaches for these diseases, remains challenging. Part of the explanation for this failure may be the genetic differences-some targets not being conserved between species-and, most importantly, the differences in regulation of gene expression. This prompts the use of human-derived models to study NDDS. The generation of human induced pluripotent stem cells (hIPSCs) added a new suitable alternative to overcome species limitations, allowing for the study of human neuronal development while maintaining the genetic background of the donor patient. Several hIPSC models of NDDs already proved their worth by mimicking several pathological phenotypes found in humans. In this review, we highlight the utility of hIPSCs to pave new paths for NDD research and development of new therapeutic tools, summarize the challenges and advances of hIPSC-culture and neuronal differentiation protocols and discuss the best way to take advantage of these models, illustrating this with examples of success for some NDDs.
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Fries GR, Saldana VA, Finnstein J, Rein T. Molecular pathways of major depressive disorder converge on the synapse. Mol Psychiatry 2023; 28:284-297. [PMID: 36203007 PMCID: PMC9540059 DOI: 10.1038/s41380-022-01806-1] [Citation(s) in RCA: 104] [Impact Index Per Article: 104.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 09/07/2022] [Accepted: 09/14/2022] [Indexed: 01/07/2023]
Abstract
Major depressive disorder (MDD) is a psychiatric disease of still poorly understood molecular etiology. Extensive studies at different molecular levels point to a high complexity of numerous interrelated pathways as the underpinnings of depression. Major systems under consideration include monoamines, stress, neurotrophins and neurogenesis, excitatory and inhibitory neurotransmission, mitochondrial dysfunction, (epi)genetics, inflammation, the opioid system, myelination, and the gut-brain axis, among others. This review aims at illustrating how these multiple signaling pathways and systems may interact to provide a more comprehensive view of MDD's neurobiology. In particular, considering the pattern of synaptic activity as the closest physical representation of mood, emotion, and conscience we can conceptualize, each pathway or molecular system will be scrutinized for links to synaptic neurotransmission. Models of the neurobiology of MDD will be discussed as well as future actions to improve the understanding of the disease and treatment options.
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Affiliation(s)
- Gabriel R. Fries
- grid.267308.80000 0000 9206 2401Translational Psychiatry Program, Faillace Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston, 1941 East Rd, Houston, TX 77054 USA ,grid.240145.60000 0001 2291 4776Neuroscience Graduate Program, The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, 6767 Bertner Ave, Houston, TX 77030 USA
| | - Valeria A. Saldana
- grid.262285.90000 0000 8800 2297Frank H. Netter MD School of Medicine at Quinnipiac University, 370 Bassett Road, North Haven, CT 06473 USA
| | - Johannes Finnstein
- grid.419548.50000 0000 9497 5095Department of Translational Research in Psychiatry, Project Group Molecular Pathways of Depression, Max Planck Institute of Psychiatry, Kraepelinstr. 10, 80804 Munich, Germany
| | - Theo Rein
- Department of Translational Research in Psychiatry, Project Group Molecular Pathways of Depression, Max Planck Institute of Psychiatry, Kraepelinstr. 10, 80804, Munich, Germany.
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Hingorani M, Viviani AML, Sanfilippo JE, Janušonis S. High-resolution spatiotemporal analysis of single serotonergic axons in an in vitro system. Front Neurosci 2022; 16:994735. [PMID: 36353595 PMCID: PMC9638127 DOI: 10.3389/fnins.2022.994735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 09/28/2022] [Indexed: 12/04/2022] Open
Abstract
Vertebrate brains have a dual structure, composed of (i) axons that can be well-captured with graph-theoretical methods and (ii) axons that form a dense matrix in which neurons with precise connections operate. A core part of this matrix is formed by axons (fibers) that store and release 5-hydroxytryptamine (5-HT, serotonin), an ancient neurotransmitter that supports neuroplasticity and has profound implications for mental health. The self-organization of the serotonergic matrix is not well understood, despite recent advances in experimental and theoretical approaches. In particular, individual serotonergic axons produce highly stochastic trajectories, fundamental to the construction of regional fiber densities, but further advances in predictive computer simulations require more accurate experimental information. This study examined single serotonergic axons in culture systems (co-cultures and monolayers), by using a set of complementary high-resolution methods: confocal microscopy, holotomography (refractive index-based live imaging), and super-resolution (STED) microscopy. It shows that serotonergic axon walks in neural tissue may strongly reflect the stochastic geometry of this tissue and it also provides new insights into the morphology and branching properties of serotonergic axons. The proposed experimental platform can support next-generation analyses of the serotonergic matrix, including seamless integration with supercomputing approaches.
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Disturbance of phylogenetic layer-specific adaptation of human brain gene expression in Alzheimer's disease. Sci Rep 2021; 11:20200. [PMID: 34642398 PMCID: PMC8511061 DOI: 10.1038/s41598-021-99760-5] [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: 08/09/2021] [Accepted: 09/28/2021] [Indexed: 11/08/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder with typical neuropathological hallmarks, such as neuritic plaques and neurofibrillary tangles, preferentially found at layers III and V. The distribution of both hallmarks provides the basis for the staging of AD, following a hierarchical pattern throughout the cerebral cortex. To unravel the background of this layer-specific vulnerability, we evaluated differential gene expression of supragranular and infragranular layers and subcortical white matter in both healthy controls and AD patients. We identified AD-associated layer-specific differences involving protein-coding and non-coding sequences, most of those present in the subcortical white matter, thus indicating a critical role for long axons and oligodendrocytes in AD pathomechanism. In addition, GO analysis identified networks containing synaptic vesicle transport, vesicle exocytosis and regulation of neurotransmitter levels. Numerous AD-associated layer-specifically expressed genes were previously reported to undergo layer-specific switches in recent hominid brain evolution between layers V and III, i.e., those layers that are most vulnerable to AD pathology. Against the background of our previous finding of accelerated evolution of AD-specific gene expression, here we suggest a critical role in AD pathomechanism for this phylogenetic layer-specific adaptation of gene expression, which is most prominently seen in the white matter compartment.
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Tate K, Kirk B, Tseng A, Ulffers A, Litwa K. Effects of the Selective Serotonin Reuptake Inhibitor Fluoxetine on Developing Neural Circuits in a Model of the Human Fetal Cortex. Int J Mol Sci 2021; 22:10457. [PMID: 34638815 PMCID: PMC8508811 DOI: 10.3390/ijms221910457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/23/2021] [Accepted: 09/23/2021] [Indexed: 02/02/2023] Open
Abstract
The developing prenatal brain is particularly susceptible to environmental disturbances. During prenatal brain development, synapses form between neurons, resulting in neural circuits that support complex cognitive functions. In utero exposure to environmental factors such as pharmaceuticals that alter the process of synapse formation increases the risk of neurodevelopmental abnormalities. However, there is a lack of research into how specific environmental factors directly impact the developing neural circuitry of the human brain. For example, selective serotonin reuptake inhibitors are commonly used throughout pregnancy to treat depression, yet their impact on the developing fetal brain remains unclear. Recently, human brain models have provided unprecedented access to the critical window of prenatal brain development. In the present study, we used human neurons and cortical spheroids to determine whether the selective serotonin reuptake inhibitor fluoxetine alters neurite and synapse formation and the development of spontaneous activity within neural circuits. We demonstrate that cortical spheroids express serotonin transporter, thus recapitulating the early developmental expression of serotonin transporter associated with cortical pyramidal neurons. Cortical spheroids also appropriately express serotonin receptors, such as synaptic 5-HT2A and glial 5-HT5A. To determine whether fluoxetine can affect developing neural circuits independent of serotonergic innervation from the dorsal and medial raphe nuclei, we treated cortical neurons and spheroids with fluoxetine. Fluoxetine alters neurite formation in a dose-dependent fashion. Intriguingly, in cortical spheroids, neither acute nor chronic fluoxetine significantly altered excitatory synapse formation. However, only acute, but not chronic fluoxetine exposure altered inhibitory synaptogenesis. Finally, fluoxetine reversibly suppresses neuronal activity in a dose-dependent manner. These results demonstrate that fluoxetine can acutely alter synaptic function in developing neural circuits, but the effects were not long-lasting. This work provides a foundation for future studies to combine serotonergic innervation with cortical spheroids and assess the contributions of fluoxetine-induced alterations in serotonin levels to brain development.
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Affiliation(s)
- Kinsley Tate
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (K.T.); (B.K.); (A.T.); (A.U.)
- Graduate Program in Biomedical Engineering, Department of Engineering, College of Engineering and Technology, East Carolina University, Greenville, NC 27834, USA
| | - Brenna Kirk
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (K.T.); (B.K.); (A.T.); (A.U.)
| | - Alisia Tseng
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (K.T.); (B.K.); (A.T.); (A.U.)
| | - Abigail Ulffers
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (K.T.); (B.K.); (A.T.); (A.U.)
| | - Karen Litwa
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (K.T.); (B.K.); (A.T.); (A.U.)
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Newman-Tancredi A, Depoortère RY, Kleven MS, Kołaczkowski M, Zimmer L. Translating biased agonists from molecules to medications: Serotonin 5-HT 1A receptor functional selectivity for CNS disorders. Pharmacol Ther 2021; 229:107937. [PMID: 34174274 DOI: 10.1016/j.pharmthera.2021.107937] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/01/2021] [Accepted: 06/17/2021] [Indexed: 12/18/2022]
Abstract
Biased agonism (or "functional selectivity") at G-protein-coupled receptors has attracted rapidly increasing interest as a means to improve discovery of more efficacious and safer pharmacotherapeutics. However, most studies are limited to in vitro tests of cellular signaling and few biased agonists have progressed to in vivo testing. As concerns 5-HT1A receptors, which exert a major control of serotonergic signaling in diverse CNS regions, study of biased agonism has previously been limited by the poor target selectivity and/or partial agonism of classically available ligands. However, a new generation of highly selective, efficacious and druggable agonists has advanced the study of biased agonism at this receptor and created new therapeutic opportunities. These novel agonists show differential properties for G-protein signaling, cellular signaling (particularly pERK), electrophysiological effects, neurotransmitter release, neuroimaging by PET and pharmacoMRI, and behavioral tests of mood, motor activity and side effects. Overall, NLX-101 (a.k.a. F15599) exhibits preferential activation of cortical and brain stem 5-HT1A receptors, whereas NLX-112 (a.k.a. befiradol or F13640) shows prominent activation of 5-HT1A autoreceptors in Raphe nuclei and in regions associated with motor control. Accordingly, NLX-101 is potently active in rodent models of depression and respiratory control, whereas NLX-112 shows promising activity in models of Parkinson's disease across several species - rat, marmoset and macaque. Moreover, NLX-112 has also been labeled with 18F to produce the first agonist PET radiopharmaceutical (known as [18F]-F13640) for investigation of the active state of 5-HT1A receptors in rodent, primate and human. The structure-functional activity relationships of biased agonists have been investigated by receptor modeling and novel compounds have been identified which exhibit increased affinity at 5-HT1A receptors and new profiles of cellular signaling bias, notably for β-arrestin recruitment versus pERK. Taken together, the data suggest that 5-HT1A receptor biased agonists constitute potentially superior pharmacological agents for treatment of CNS disorders involving serotonergic mechanisms.
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Affiliation(s)
| | | | | | | | - Luc Zimmer
- Université Claude Bernard Lyon1, Lyon, France; Hospices Civils de Lyon, Lyon, France; Lyon Neuroscience Research Center, CNRS-INSERM, France
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