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Belelli D, Lambert JJ, Wan MLY, Monteiro AR, Nutt DJ, Swinny JD. From bugs to brain: unravelling the GABA signalling networks in the brain-gut-microbiome axis. Brain 2025; 148:1479-1506. [PMID: 39716883 PMCID: PMC12074267 DOI: 10.1093/brain/awae413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2024] [Revised: 11/21/2024] [Accepted: 12/01/2024] [Indexed: 12/25/2024] Open
Abstract
Convergent data across species paint a compelling picture of the critical role of the gut and its resident microbiota in several brain functions and disorders. The chemicals mediating communication along these sophisticated highways of the brain-gut-microbiome (BGM) axis include both microbiota metabolites and classical neurotransmitters. Amongst the latter, GABA is fundamental to brain function, mediating most neuronal inhibition. Until recently, GABA's role and specific molecular targets in the periphery within the BGM axis had received limited attention. Yet, GABA is produced by neuronal and non-neuronal elements of the BGM, and recently, GABA-modulating bacteria have been identified as key players in GABAergic gut systems, indicating that GABA-mediated signalling is likely to transcend physiological boundaries and species. We review the available evidence to better understand how GABA facilitates the integration of molecularly and functionally disparate systems to bring about overall homeostasis and how GABA perturbations within the BGM axis can give rise to multi-system medical disorders, thereby magnifying the disease burden and the challenges for patient care. Analysis of transcriptomic databases revealed significant overlaps between GABAAR subunits expressed in the human brain and gut. However, in the gut, there are notable expression profiles for a select number of subunits that have received limited attention to date but could be functionally relevant for BGM axis homeostasis. GABAergic signalling, via different receptor subtypes, directly regulates BGM homeostasis by modulating the excitability of neurons within brain centres responsible for gastrointestinal (GI) function in a sex-dependent manner, potentially revealing mechanisms underlying the greater prevalence of GI disturbances in females. Apart from such top-down regulation of the BGM axis, a diverse group of cell types, including enteric neurons, glia, enteroendocrine cells, immune cells and bacteria, integrate peripheral GABA signals to influence brain functions and potentially contribute to brain disorders. We propose several priorities for this field, including the exploitation of available technologies to functionally dissect components of these GABA pathways within the BGM, with a focus on GI and brain-behaviour-disease. Furthermore, in silico ligand-receptor docking analyses using relevant bacterial metabolomic datasets, coupled with advances in knowledge of GABAAR 3D structures, could uncover new ligands with novel therapeutic potential. Finally, targeted design of dietary interventions is imperative to advancing their therapeutic potential to support GABA homeostasis across the BGM axis.
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Affiliation(s)
- Delia Belelli
- GABA Labs (Research) Ltd., Hemel Hempstead HP2 5HD, UK
- Division of Neuroscience, School of Medicine, Medical Sciences Institute, Dundee University, Dundee DD1 5HL, UK
- School of Medicine, Pharmacy & Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK
| | - Jeremy J Lambert
- Division of Neuroscience, School of Medicine, Medical Sciences Institute, Dundee University, Dundee DD1 5HL, UK
| | - Murphy Lam Yim Wan
- School of Medicine, Pharmacy & Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK
| | - Ana Rita Monteiro
- School of Medicine, Pharmacy & Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK
| | - David J Nutt
- GABA Labs (Research) Ltd., Hemel Hempstead HP2 5HD, UK
- Division of Psychiatry, Department of Brain Sciences, Imperial College London, London W12 0NN, UK
| | - Jerome D Swinny
- School of Medicine, Pharmacy & Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK
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2
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Lopez SMM, Lee JR, Lin WC. A subtype-selective photoswitchable agonist for precise manipulation of GABA A receptors. Br J Pharmacol 2025. [PMID: 40288764 DOI: 10.1111/bph.70066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 02/19/2025] [Accepted: 03/16/2025] [Indexed: 04/29/2025] Open
Abstract
BACKGROUND AND PURPOSE Neuronal inhibition is largely mediated by type-A GABA receptors (GABAARs), a family of ligand-gated chloride-permeable channels, which can be sub-classified by their subunit composition. Unravelling the function and distribution of each GABAAR subtype is essential for a holistic understanding of GABAergic inhibition in health and diseases. Photopharmacology, a technique that utilises light-sensitive compounds to precisely manipulate endogenous proteins, is powerful for this purpose. To resolve the molecular complexity of neuronal inhibition, we aimed to develop subtype-selective photoswitchable agonists for GABAARs. EXPERIMENTAL APPROACH Inspired by THIP (gaboxadol), an agonist selective for δ subunit-containing GABAARs (δ-GABAARs), we merged a photoswitch moiety (azobenzene) with an analogue of THIP (isoguvacine) to construct Az-IGU. Using whole-cell voltage-clamp recording, Az-IGU was tested on 13 GABAAR subtypes expressed in human embryonic kidney (HEK) cells. Optical activation of endogenous GABAARs was examined via electrophysiology in cultured cortical neurons. KEY RESULTS In HEK cells, Az-IGU exerted reversible photo-agonism selectively for α4β3δ and α6β3δ GABAARs, two major mediators of tonic inhibition. Pharmacological and mutagenesis studies suggested that activation of the α4β3δ GABAAR involves interaction between Az-IGU and the GABA-binding pocket and is strongly correlated with the spontaneous activity of the receptor. In cultured cortical neurons, photoisomerisation of Az-IGU triggered responses that enabled reversible control of action potential firing. CONCLUSIONS AND IMPLICATIONS GABAARs are potential therapeutic targets for many disorders. However, their physiological and pathophysiological roles remain largely unexplored. Az-IGU may enable photopharmacological studies of α4/6β3δ GABAARs, providing new opportunities for biomedical and neurobiological applications.
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Affiliation(s)
- Simon Miguel M Lopez
- Taiwan International Graduate Program in Molecular Medicine, National Yang Ming Chiao Tung University and Academia Sinica, Taipei, Taiwan
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Jay-Ron Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Wan-Chen Lin
- Taiwan International Graduate Program in Molecular Medicine, National Yang Ming Chiao Tung University and Academia Sinica, Taipei, Taiwan
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
- Neuroscience Program of Academia Sinica (NPAS), Academia Sinica, Taipei, Taiwan
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3
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Michałowski MA, Kłopotowski K, Wiera G, Czyżewska MM, Mozrzymas JW. Molecular mechanisms of the GABA type A receptor function. Q Rev Biophys 2025; 58:e3. [PMID: 39806800 DOI: 10.1017/s0033583524000179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2025]
Abstract
The GABA type A receptor (GABAAR) belongs to the family of pentameric ligand-gated ion channels and plays a key role in inhibition in adult mammalian brains. Dysfunction of this macromolecule may lead to epilepsy, anxiety disorders, autism, depression, and schizophrenia. GABAAR is also a target for multiple physiologically and clinically relevant modulators, such as benzodiazepines (BDZs), general anesthetics, and neurosteroids. The first GABAAR structure appeared in 2014, but the past years have brought a particularly abundant surge in structural data for these receptors with various ligands and modulators. Although the open conformation remains elusive, this novel information has pushed the structure-function studies to an unprecedented level. Electrophysiology, mutagenesis, photolabeling, and in silico simulations, guided by novel structural information, shed new light on the molecular mechanisms of receptor functioning. The main goal of this review is to present the current knowledge of GABAAR functional and structural properties. The review begins with an outline of the functional and structural studies of GABAAR, accompanied by some methodological considerations, especially biophysical methods, enabling the reader to follow how major breakthroughs in characterizing GABAAR features have been achieved. The main section provides a comprehensive analysis of the functional significance of specific structural elements in GABAARs. We additionally summarize the current knowledge on the binding sites for major GABAAR modulators, referring to the molecular underpinnings of their action. The final chapter of the review moves beyond examining GABAAR as an isolated macromolecule and describes the interactions of the receptor with other proteins in a broader context of inhibitory plasticity. In the final section, we propose a general conclusion that agonist binding to the orthosteric binding sites appears to rely on local interactions, whereas conformational transitions of bound macromolecule (gating) and allosteric modulation seem to reflect more global phenomena involving vast portions of the macromolecule.
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Affiliation(s)
- Michał A Michałowski
- Faculty of Medicine, Department of Biophysics and Neuroscience, Wroclaw Medical University, Wrocław, Poland
| | - Karol Kłopotowski
- Faculty of Medicine, Department of Biophysics and Neuroscience, Wroclaw Medical University, Wrocław, Poland
| | - Grzegorz Wiera
- Faculty of Medicine, Department of Biophysics and Neuroscience, Wroclaw Medical University, Wrocław, Poland
| | - Marta M Czyżewska
- Faculty of Medicine, Department of Biophysics and Neuroscience, Wroclaw Medical University, Wrocław, Poland
| | - Jerzy W Mozrzymas
- Faculty of Medicine, Department of Biophysics and Neuroscience, Wroclaw Medical University, Wrocław, Poland
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Aroniadou-Anderjaska V, Figueiredo TH, De Araujo Furtado M, Pidoplichko VI, Lumley LA, Braga MFM. Alterations in GABA A receptor-mediated inhibition triggered by status epilepticus and their role in epileptogenesis and increased anxiety. Neurobiol Dis 2024; 200:106633. [PMID: 39117119 DOI: 10.1016/j.nbd.2024.106633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 07/31/2024] [Accepted: 08/05/2024] [Indexed: 08/10/2024] Open
Abstract
The triggers of status epilepticus (SE) in non-epileptic patients can vary widely, from idiopathic causes to exposure to chemoconvulsants. Regardless of its etiology, prolonged SE can cause significant brain damage, commonly resulting in the development of epilepsy, which is often accompanied by increased anxiety. GABAA receptor (GABAAR)-mediated inhibition has a central role among the mechanisms underlying brain damage and the ensuing epilepsy and anxiety. During SE, calcium influx primarily via ionotropic glutamate receptors activates signaling cascades which trigger a rapid internalization of synaptic GABAARs; this weakens inhibition, exacerbating seizures and excitotoxicity. GABAergic interneurons are more susceptible to excitotoxic death than principal neurons. During the latent period of epileptogenesis, the aberrant reorganization in synaptic interactions that follow interneuronal loss in injured brain regions, leads to the formation of hyperexcitable, seizurogenic neuronal circuits, along with disturbances in brain oscillatory rhythms. Reduction in the spontaneous, rhythmic "bursts" of IPSCs in basolateral amygdala neurons is likely to play a central role in anxiogenesis. Protecting interneurons during SE is key to preventing both epilepsy and anxiety. Antiglutamatergic treatments, including antagonism of calcium-permeable AMPA receptors, can be expected to control seizures and reduce excitotoxicity not only by directly suppressing hyperexcitation, but also by counteracting the internalization of synaptic GABAARs. Benzodiazepines, as delayed treatment of SE, have low efficacy due to the reduction and dispersion of their targets (the synaptic GABAARs), but also because themselves contribute to further reduction of available GABAARs at the synapse; furthermore, benzodiazepines may be completely ineffective in the immature brain.
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Affiliation(s)
- Vassiliki Aroniadou-Anderjaska
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA; Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
| | - Taiza H Figueiredo
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
| | - Marcio De Araujo Furtado
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Volodymyr I Pidoplichko
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
| | - Lucille A Lumley
- U.S. Army Medical Research Institute of Chemical Defense, Aberdeen, Proving Ground, MD, USA.
| | - Maria F M Braga
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA; Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
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Mitchell SJ, Phillips GD, Tench B, Li Y, Belelli D, Martin SJ, Swinny JD, Kelly L, Atack JR, Paradowski M, Lambert JJ. Neurosteroid Modulation of Synaptic and Extrasynaptic GABA A Receptors of the Mouse Nucleus Accumbens. Biomolecules 2024; 14:460. [PMID: 38672476 PMCID: PMC11048561 DOI: 10.3390/biom14040460] [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: 02/14/2024] [Revised: 03/29/2024] [Accepted: 04/04/2024] [Indexed: 04/28/2024] Open
Abstract
The recent approval of formulations of the endogenous neurosteroid allopregnanolone (brexanolone) and the synthetic neuroactive steroid SAGE-217 (zuranolone) to treat postpartum depression (PPD) has encouraged further research to elucidate why these potent enhancers of GABAAR function are clinically effective in this condition. Dopaminergic projections from the ventral tegmental area (VTA) to the nucleus accumbens are associated with reward/motivation and brain imaging studies report that individuals with PPD show reduced activity of this pathway in response to reward and infant engagement. However, the influence of neurosteroids on GABA-ergic transmission in the nucleus accumbens has received limited attention. Here, we investigate, in the medium spiny neurons (MSNs) of the mouse nucleus accumbens core, the effect of allopregnanolone, SAGE-217 and other endogenous and synthetic steroids of interest on fast phasic and tonic inhibition mediated by synaptic (α1/2βγ2) and extrasynaptic (α4βδ) GABAARs, respectively. We present evidence suggesting the resident tonic current results from the spontaneous opening of δ-GABAARs, where the steroid-enhanced tonic current is GABA-dependent. Furthermore, we demonstrate local neurosteroid synthesis in the accumbal slice preparation and reveal that GABA-ergic neurotransmission of MSNs is influenced by an endogenous neurosteroid tone. Given the dramatic fluctuations in allopregnanolone levels during pregnancy and postpartum, this neurosteroid-mediated local fine-tuning of GABAergic transmission in the MSNs will probably be perturbed.
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Affiliation(s)
- Scott J. Mitchell
- Division of Cellular & Systems Medicine, School of Medicine, Medical Sciences Institute, Dundee University, Dow Street, Dundee DD1 5HL, UK; (S.J.M.); (G.D.P.); (B.T.); (Y.L.); (D.B.); (S.J.M.)
| | - Grant D. Phillips
- Division of Cellular & Systems Medicine, School of Medicine, Medical Sciences Institute, Dundee University, Dow Street, Dundee DD1 5HL, UK; (S.J.M.); (G.D.P.); (B.T.); (Y.L.); (D.B.); (S.J.M.)
| | - Becks Tench
- Division of Cellular & Systems Medicine, School of Medicine, Medical Sciences Institute, Dundee University, Dow Street, Dundee DD1 5HL, UK; (S.J.M.); (G.D.P.); (B.T.); (Y.L.); (D.B.); (S.J.M.)
| | - Yunkai Li
- Division of Cellular & Systems Medicine, School of Medicine, Medical Sciences Institute, Dundee University, Dow Street, Dundee DD1 5HL, UK; (S.J.M.); (G.D.P.); (B.T.); (Y.L.); (D.B.); (S.J.M.)
| | - Delia Belelli
- Division of Cellular & Systems Medicine, School of Medicine, Medical Sciences Institute, Dundee University, Dow Street, Dundee DD1 5HL, UK; (S.J.M.); (G.D.P.); (B.T.); (Y.L.); (D.B.); (S.J.M.)
| | - Stephen J. Martin
- Division of Cellular & Systems Medicine, School of Medicine, Medical Sciences Institute, Dundee University, Dow Street, Dundee DD1 5HL, UK; (S.J.M.); (G.D.P.); (B.T.); (Y.L.); (D.B.); (S.J.M.)
| | - Jerome D. Swinny
- School of Pharmacy & Biomedical Sciences, St. Michael’s Building, University of Portsmouth, White Swan Road, Portsmouth PO1 2DT, UK; (J.D.S.); (L.K.)
| | - Louise Kelly
- School of Pharmacy & Biomedical Sciences, St. Michael’s Building, University of Portsmouth, White Swan Road, Portsmouth PO1 2DT, UK; (J.D.S.); (L.K.)
| | - John R. Atack
- Main Building, Medicines Discovery Institute, Park Place, Cardiff University, Cardiff, CF10 3AT, UK; (J.R.A.); (M.P.)
| | - Michael Paradowski
- Main Building, Medicines Discovery Institute, Park Place, Cardiff University, Cardiff, CF10 3AT, UK; (J.R.A.); (M.P.)
| | - Jeremy J. Lambert
- Division of Cellular & Systems Medicine, School of Medicine, Medical Sciences Institute, Dundee University, Dow Street, Dundee DD1 5HL, UK; (S.J.M.); (G.D.P.); (B.T.); (Y.L.); (D.B.); (S.J.M.)
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6
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Tessier CJG, Emlaw JR, Sturgeon RM, daCosta CJB. Derepression may masquerade as activation in ligand-gated ion channels. Nat Commun 2023; 14:1907. [PMID: 37019877 PMCID: PMC10076327 DOI: 10.1038/s41467-023-36770-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 02/16/2023] [Indexed: 04/07/2023] Open
Abstract
Agonists are ligands that bind to receptors and activate them. In the case of ligand-gated ion channels, such as the muscle-type nicotinic acetylcholine receptor, mechanisms of agonist activation have been studied for decades. Taking advantage of a reconstructed ancestral muscle-type β-subunit that forms spontaneously activating homopentamers, here we show that incorporation of human muscle-type α-subunits appears to repress spontaneous activity, and furthermore that the presence of agonist relieves this apparent α-subunit-dependent repression. Our results demonstrate that rather than provoking channel activation/opening, agonists may instead 'inhibit the inhibition' of intrinsic spontaneous activity. Thus, agonist activation may be the apparent manifestation of agonist-induced derepression. These results provide insight into intermediate states that precede channel opening and have implications for the interpretation of agonism in ligand-gated ion channels.
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Affiliation(s)
- Christian J G Tessier
- Department of Chemistry and Biomolecular Sciences, Centre for Chemical and Synthetic Biology, University of Ottawa, Ottawa, ON, Canada
| | - Johnathon R Emlaw
- Department of Chemistry and Biomolecular Sciences, Centre for Chemical and Synthetic Biology, University of Ottawa, Ottawa, ON, Canada
| | - Raymond M Sturgeon
- Department of Chemistry and Biomolecular Sciences, Centre for Chemical and Synthetic Biology, University of Ottawa, Ottawa, ON, Canada
| | - Corrie J B daCosta
- Department of Chemistry and Biomolecular Sciences, Centre for Chemical and Synthetic Biology, University of Ottawa, Ottawa, ON, Canada.
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7
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Menzikov SA, Zaichenko DM, Moskovtsev AA, Morozov SG, Kubatiev AA. Zinc Inhibits the GABA AR/ATPase during Postnatal Rat Development: The Role of Cysteine Residue. Int J Mol Sci 2023; 24:ijms24032764. [PMID: 36769085 PMCID: PMC9917249 DOI: 10.3390/ijms24032764] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/24/2023] [Accepted: 01/26/2023] [Indexed: 02/04/2023] Open
Abstract
Zinc ions (Zn2+) are concentrated in various brain regions and can act as a neuromodulator, targeting a wide spectrum of postsynaptic receptors and enzymes. Zn2+ inhibits the GABAARs, and its potency is profoundly affected by the subunit composition and neuronal developmental stage. Although the extracellular amino acid residues of the receptor's hetero-oligomeric structure are preferred for Zn2+ binding, there are intracellular sites that, in principle, could coordinate its potency. However, their role in modulating the receptor function during postembryonic development remains unclear. The GABAAR possesses an intracellular ATPase that enables the energy-dependent anion transport via a pore. Here, we propose a mechanistic and molecular basis for the inhibition of intracellular GABAAR/ATPase function by Zn2+ in neonatal and adult rats. The enzymes within the scope of GABAAR performance as Cl-ATPase and then as Cl-, HCO3-ATPase form during the first week of postnatal rat development. In addition, we have shown that the Cl-ATPase form belongs to the β1 subunit, whereas the β3 subunit preferably possesses the Cl-, HCO3-ATPase activity. We demonstrated that a Zn2+ with variable efficacy inhibits the GABAAR as well as the ATPase activities of immature or mature neurons. Using fluorescence recording in the cortical synaptoneurosomes (SNs), we showed a competitive association between Zn2+ and NEM in parallel changes both in the ATPase activity and the GABAAR-mediated Cl- and HCO3- fluxes. Finally, by site-directed mutagenesis, we identified in the M3 domain of β subunits the cysteine residue (C313) that is essential for the manifestation of Zn2+ potency.
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8
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Tessier CJG, Sturgeon RM, Emlaw JR, McCluskey GD, Pérez-Areales FJ, daCosta CJB. Ancestral acetylcholine receptor β-subunit forms homopentamers that prime before opening spontaneously. eLife 2022; 11:76504. [PMID: 35781368 PMCID: PMC9365395 DOI: 10.7554/elife.76504] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
Human adult muscle-type acetylcholine receptors are heteropentameric ion channels formed from two α-subunits, and one each of the β-, d-, and e-subunits. To form functional channels, the subunits must assemble with one another in a precise stoichiometry and arrangement. Despite being different, the four subunits share a common ancestor that is presumed to have formed homopentamers. The extent to which the properties of the modern-day receptor result from its subunit complexity is unknown. Here we discover that a reconstructed ancestral muscle-type β-subunit can form homopentameric ion channels. These homopentamers open spontaneously and display single-channel hallmarks of muscle-type acetylcholine receptor activity. Our findings attest to the homopentameric origin of the muscle-type acetylcholine receptor, and demonstrate that signature features of its function are both independent of agonist and do not necessitate the complex heteropentameric architecture of the modern-day protein.
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Affiliation(s)
| | - R Michel Sturgeon
- Center for Chemical and Synthetic Biology, University of Ottawa, Ottawa, Canada
| | - Johnathon R Emlaw
- Center for Chemical and Synthetic Biology, University of Ottawa, Ottawa, Canada
| | - Gregory D McCluskey
- Center for Chemical and Synthetic Biology, University of Ottawa, Ottawa, Canada
| | | | - Corrie J B daCosta
- Center for Chemical and Synthetic Biology, University of Ottawa, Ottawa, Canada
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9
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Vien TN, Ackley MA, Doherty JJ, Moss SJ, Davies PA. Preventing Phosphorylation of the GABAAR β3 Subunit Compromises the Behavioral Effects of Neuroactive Steroids. Front Mol Neurosci 2022; 15:817996. [PMID: 35431797 PMCID: PMC9009507 DOI: 10.3389/fnmol.2022.817996] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 03/09/2022] [Indexed: 11/26/2022] Open
Abstract
Neuroactive steroids (NASs) have potent anxiolytic, anticonvulsant, sedative, and hypnotic actions, that reflect in part their efficacy as GABAAR positive allosteric modulators (PAM). In addition to this, NAS exert metabotropic effects on GABAergic inhibition via the activation of membrane progesterone receptors (mPRs), which are G-protein coupled receptors. mPR activation enhances the phosphorylation of residues serine 408 and 409 (S408/9) in the β3 subunit of GABAARs, increasing their accumulation in the plasma membrane leading to a sustained increase in tonic inhibition. To explore the significance of NAS-induced phosphorylation of GABAARs, we used mice in which S408/9 in the β3 subunit have been mutated to alanines, mutations that prevent the metabotropic actions of NASs on GABAAR function while preserving NAS allosteric potentiation of GABAergic current. While the sedative actions of NAS were comparable to WT, their anxiolytic actions were reduced in S408/9A mice. Although the induction of hypnosis by NAS were maintained in the mutant mice the duration of the loss of righting reflex was significantly shortened. Finally, ability of NAS to terminate diazepam pharmacoresistant seizures was abolished in S408/9A mice. In conclusion, our results suggest that S408/9 in the GABAAR β3 subunit contribute to the anxiolytic and anticonvulsant efficacy of NAS, in addition to their ability to regulate the loss of righting reflex.
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Affiliation(s)
- Thuy N. Vien
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Michael A. Ackley
- Research and Non-clinical Development, Sage Therapeutics, Inc., Cambridge, MA, United States
| | - James J. Doherty
- Research and Non-clinical Development, Sage Therapeutics, Inc., Cambridge, MA, United States
| | - Stephen J. Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
- *Correspondence: Stephen J. Moss,
| | - Paul A. Davies
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
- Paul A. Davies,
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10
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Yadav D, Kumar P. Restoration and targeting of aberrant neurotransmitters in Parkinson's disease therapeutics. Neurochem Int 2022; 156:105327. [PMID: 35331828 DOI: 10.1016/j.neuint.2022.105327] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/18/2022] [Accepted: 03/17/2022] [Indexed: 12/13/2022]
Abstract
Neurotransmitters are considered as a fundamental regulator in the process of neuronal growth, differentiation and survival. Parkinson's Disease (PD) occurs due to extensive damage of dopamine-producing neurons; this causes dopamine deficits in the midbrain, followed by the alternation of various other neurotransmitters (glutamate, GABA, serotonin, etc.). It has been observed that fluctuation of neurotransmission in the basal ganglia exhibits a great impact on the pathophysiology of PD. Dopamine replacement therapy, such as the use of L-DOPA, can increase the dopamine level, but it majorly ameliorates the motor symptoms and is also associated with long-term complications (for e.g., LID). While the non-dopaminergic system can efficiently target non-motor symptoms, for instance, the noradrenergic system regulates the synthesis of BDNF via the MAPK pathway, which is important in learning and memory. Herein, we briefly discuss the role of different neurotransmitters, implementation of neurotransmitter receptors in PD. We also illustrate the recent advances of neurotransmitter-based drugs, which are currently under in vivo and clinical studies. Reinstating normal neurotransmitter levels has been believed to be advantageous in the treatment of PD. Thus, there is an increasing demand for drugs that can specifically target the neurotransmission system and reinstate the normal levels of neurotransmitters, which might prevent or delay neurodegeneration in PD.
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Affiliation(s)
- Divya Yadav
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi, India; Delhi Technological University (Formerly Delhi College of Engineering), Delhi, 110042, India
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi, India; Delhi Technological University (Formerly Delhi College of Engineering), Delhi, 110042, India.
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11
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Sun X, Chen X, Zhao J, Ma C, Yan C, Liswaniso S, Xu R, Qin N. Transcriptome comparative analysis of ovarian follicles reveals the key genes and signaling pathways implicated in hen egg production. BMC Genomics 2021; 22:899. [PMID: 34911438 PMCID: PMC8672471 DOI: 10.1186/s12864-021-08213-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 11/26/2021] [Indexed: 01/19/2023] Open
Abstract
Background Ovarian follicle development plays an important role in determination of poultry egg production. The follicles at the various developmental stages possess their own distinct molecular genetic characteristics and have different biological roles in chicken ovary development and function. In the each stage, several genes of follicle-specific expression and biological pathways are involved in the vary-sized follicular development and physiological events. Identification of the pivotal genes and signaling pathways that control the follicular development is helpful for understanding their exact regulatory functions and molecular mechanisms underlying egg-laying traits of laying hens. Results The comparative mRNA transcriptomic analysis of ovarian follicles at three key developmental stages including slow growing white follicles (GWF), small yellow follicles (SYF) of recruitment into the hierarchy, and differentiated large yellow follicles (LYF), was accomplished in the layers with lower and higher egg production. Totally, 137, 447, and 229 of up-regulated differentially expressed genes (DEGs), and 99, 97, and 157 of down-regulated DEGs in the GWF, SYF and LYF follicles, including VIPR1, VIPR2, ADRB2, and HSD17B1 were identified, respectively. Moreover, NDUFAB1 and GABRA1 genes, two most promising candidates potentially associated with egg-laying performance were screened out from the 13 co-expressed DEGs in the GWF, SYF and LYF samples. We further investigated the biological effects of NDUFAB1 and GABRA1 on ovarian follicular development and found that NDUFAB1 promotes follicle development by stimulating granulosa cell (GC) proliferation and decreasing cell apoptosis, increases the expression of CCND1 and BCL-2 but attenuates the expression of caspase-3, and facilitates steroidogenesis by enhancing the expression of STAR and CYP11A1. In contrast, GABRA1 inhibits GC proliferation and stimulates cell apoptosis, decreases the expression of CCND1, BCL-2, STAR, and CYP11A1 but elevates the expression of caspase-3. Furthermore, the three crucial signaling pathways such as PPAR signaling pathway, cAMP signaling pathway and neuroactive ligand-receptor interaction were significantly enriched, which may play essential roles in ovarian follicle growth, differentiation, follicle selection, and maturation. Conclusions The current study provided new molecular data for insight into the regulatory mechanism underlying ovarian follicle development associated with egg production in chicken. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08213-w.
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Affiliation(s)
- Xue Sun
- Joint Laboratory of Modern Agricultural Technology International Cooperation, Ministry of Education, Jilin Agricultural University, Changchun, 130118, China.,Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China
| | - Xiaoxia Chen
- Joint Laboratory of Modern Agricultural Technology International Cooperation, Ministry of Education, Jilin Agricultural University, Changchun, 130118, China.,Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China
| | - Jinghua Zhao
- Joint Laboratory of Modern Agricultural Technology International Cooperation, Ministry of Education, Jilin Agricultural University, Changchun, 130118, China.,Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China
| | - Chang Ma
- Joint Laboratory of Modern Agricultural Technology International Cooperation, Ministry of Education, Jilin Agricultural University, Changchun, 130118, China.,Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China
| | - Chunchi Yan
- Joint Laboratory of Modern Agricultural Technology International Cooperation, Ministry of Education, Jilin Agricultural University, Changchun, 130118, China.,Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China
| | - Simushi Liswaniso
- Joint Laboratory of Modern Agricultural Technology International Cooperation, Ministry of Education, Jilin Agricultural University, Changchun, 130118, China.,Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China
| | - Rifu Xu
- Joint Laboratory of Modern Agricultural Technology International Cooperation, Ministry of Education, Jilin Agricultural University, Changchun, 130118, China. .,Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China.
| | - Ning Qin
- Joint Laboratory of Modern Agricultural Technology International Cooperation, Ministry of Education, Jilin Agricultural University, Changchun, 130118, China. .,Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China.
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