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Snelleksz M, Dean B. Higher levels of AKT-interacting protein in the frontal pole from people with schizophrenia are limited to a sub-group who have a marked deficit in cortical muscarinic M1 receptors. Psychiatry Res 2024; 341:116156. [PMID: 39236366 DOI: 10.1016/j.psychres.2024.116156] [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: 11/20/2023] [Revised: 06/29/2024] [Accepted: 07/03/2024] [Indexed: 09/07/2024]
Abstract
We are studying the molecular pathology of a sub-group within schizophrenia (∼ 25 %: termed Muscarinic Receptor Deficit subgroup of Schizophrenia (MRDS)) who can be separated because they have very low levels of cortical muscarinic M1 receptors (CHRM1). Based on our transcriptomic data from Brodmann's area ((BA) 9, 10 and 33 (controls, schizophrenia and mood disorders) and the cortex of the CHRM1-/- mouse (a molecular model of aberrant CHRM1 signaling), we predicted levels of AKT interacting protein (AKTIP), but not tubulin alpha 1b (TUBA1B) or AKT serine/threonine kinase 1 (AKT1) and pyruvate dehydrogenase kinase 1 (PDK1) (two AKTIP-functionally associated proteins), would be changed in MRDS. Hence, we used Western blotting to measure AKTIP (BA 10: controls, schizophrenia and mood disorders; BA 9: controls and schizophrenia) plus TUBA1B, AKT1 and PDK1 (BA 10: controls and schizophrenia) proteins. The only significant change with diagnosis was higher levels of AKTIP protein in BA 10 (Cohen's d = 0.73; p = 0.02) in schizophrenia compared to controls due to higher levels of AKTIP only in people with MRDS (Cohen's d = 0.80; p = 0.03). As AKTIP is involved in AKT1 signaling, our data suggests that signaling pathway is particularly disturbed in BA 10 in MRDS.
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Affiliation(s)
- Megan Snelleksz
- The Molecular Psychiatry Laboratory, The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.
| | - Brian Dean
- The Molecular Psychiatry Laboratory, The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
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Desideri F, Grazzi A, Lisi M, Setti A, Santini T, Colantoni A, Proietti G, Carvelli A, Tartaglia GG, Ballarino M, Bozzoni I. CyCoNP lncRNA establishes cis and trans RNA-RNA interactions to supervise neuron physiology. Nucleic Acids Res 2024; 52:9936-9952. [PMID: 38989616 PMCID: PMC11381359 DOI: 10.1093/nar/gkae590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 05/30/2024] [Accepted: 07/03/2024] [Indexed: 07/12/2024] Open
Abstract
The combination of morphogenetic and transcription factors together with the synergic aid of noncoding RNAs and their cognate RNA binding proteins contribute to shape motor neurons (MN) identity. Here, we extend the noncoding perspective of human MN, by detailing the molecular and biological activity of CyCoNP (as Cytoplasmic Coordinator of Neural Progenitors) a highly expressed and MN-enriched human lncRNA. Through in silico prediction, in vivo RNA purification and loss of function experiments followed by RNA-sequencing, we found that CyCoNP sustains a specific neuron differentiation program, required for the physiology of both neuroblastoma cells and hiPSC-derived MN, which mainly involves miR-4492 and NCAM1 mRNA. We propose a novel lncRNA-mediated 'dual mode' of action, in which CyCoNP acts in trans as a classical RNA sponge by sequestering miR-4492 from its pro-neuronal targets, including NCAM1 mRNA, and at the same time it plays an additional role in cis by interacting with NCAM1 mRNA and regulating the availability and localization of the miR-4492 in its proximity. These data highlight novel insights into the noncoding RNA-mediated control of human neuron physiology and point out the importance of lncRNA-mediated interactions for the spatial distribution of regulatory molecules.
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Affiliation(s)
- Fabio Desideri
- Center for Life Nano- & Neuro-Science of Istituto Italiano di Tecnologia (IIT), 00161 Rome, Italy
| | - Alessandro Grazzi
- Center for Life Nano- & Neuro-Science of Istituto Italiano di Tecnologia (IIT), 00161 Rome, Italy
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy
| | - Michela Lisi
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy
| | - Adriano Setti
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy
| | - Tiziana Santini
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy
| | - Alessio Colantoni
- Center for Life Nano- & Neuro-Science of Istituto Italiano di Tecnologia (IIT), 00161 Rome, Italy
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy
| | - Gabriele Proietti
- Centre for Human Technologies (CHT), Istituto Italiano di Tecnologia (IIT), 16152 Genova, Italy
| | - Andrea Carvelli
- Department of Neuroscience, The Scripps Research institute, La Jolla, CA 92037, USA
| | - Gian Gaetano Tartaglia
- Centre for Human Technologies (CHT), Istituto Italiano di Tecnologia (IIT), 16152 Genova, Italy
| | - Monica Ballarino
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy
| | - Irene Bozzoni
- Center for Life Nano- & Neuro-Science of Istituto Italiano di Tecnologia (IIT), 00161 Rome, Italy
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy
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Dean B, Hopper S, Scarr E. Changes in levels of the zinc transporter SLC39A12 in Brodmann's area 44: Effects of sex, suicide, CNS pH and schizophrenia. J Psychiatr Res 2024; 177:177-184. [PMID: 39024742 DOI: 10.1016/j.jpsychires.2024.07.017] [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: 04/29/2024] [Revised: 07/04/2024] [Accepted: 07/11/2024] [Indexed: 07/20/2024]
Abstract
Disturbed CNS zinc homeostasis is suggested as part of the pathophysiology of schizophrenia. Our data, from multiple studies, suggests levels of cortical RNA for the solute carrier family 39 member 12 (SLC39A12), a putative zinc transporter, is higher in people with schizophrenia and is more perturbed in a sub-group of people with the disorder that can be separated because they have very low levels of muscarinic M1 receptors (MRDS). In this study qPCR was used to measure levels of two RNA splice variants of SLC39A12 (a and b) in Brodmann's area (BA) 44 from new cohorts of controls and people with schizophrenia. For the first time, in our study cohort as a whole, we report levels of both splice variants of SLC39A12 are lower in females compared to males and there are correlations between levels of SLC39A12 a and b and CNS pH. Levels of both splice variants were also lower in people with schizophrenia who were suicide completers compared to those who were not. Accounting for these factors, we showed levels of SLC39A12 a and b were higher in BA 44 in schizophrenia compared to controls. In further analyses, with and without our previous data on SLC39A12 a and b, we confirmed changes in levels of SLC39A12 RNAs were more profound in MRDS. In conclusion, our study argues there are higher levels of SLC39A12 a and b in BA 44 in schizophrenia which could be contributing to the breakdown in CNS zinc homeostasis suggested as part of the pathophysiology of schizophrenia, particularly in those with MRDS.
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Affiliation(s)
- Brian Dean
- The Molecular Psychiatry Laboratory, The Florey, Parkville, Victoria, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia.
| | - Shaun Hopper
- The Molecular Psychiatry Laboratory, The Florey, Parkville, Victoria, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Elizabeth Scarr
- The Department of Psychiatry, The University of Melbourne, Parkville, Victoria, Australia
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Guo P, Meng C, Zhang S, Cai Y, Huang J, Shu J, Wang J, Cai C. Network-based analysis on the genes and their interactions reveals link between schizophrenia and Alzheimer's disease. Neuropharmacology 2024; 244:109802. [PMID: 38043643 DOI: 10.1016/j.neuropharm.2023.109802] [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: 07/17/2023] [Revised: 10/25/2023] [Accepted: 11/26/2023] [Indexed: 12/05/2023]
Abstract
Schizophrenia (SCZ) is a heterogeneous psychiatric disorder marked by impaired thinking, emotions, and behaviors. Studies have suggested a strong connection between SCZ and Alzheimer's disease (AD), however, controversies exist and the underlying mechanisms linking these two disorders remain largely unknown. Therefore, systematic studies of SCZ- and AD-related genes will provide valuable insights into the molecular features of these two diseases and their comorbidities. In this study, we obtained 331 SCZ-related genes, 650 AD-related genes, 65 shared genes between SCZ and AD. Enrichment analysis shown that these 65 shared genes were mainly involved in cognition, neural development, synaptic transmission, drug reactions, metabolic processes and immune related processes, suggesting a complex mechanism for the co-existence of SCZ and AD. In addition, we performed pathway enrichment analysis and found a total of 57 common pathways between SCZ and AD, which could be largely grouped into three modules: immune module, neurodevelopment module and cancer module. We eventually identified the potential disease-related genes whose interactions provide clues to the overlapping symptoms between SCZ and AD.
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Affiliation(s)
- Pan Guo
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Chao Meng
- Department of Medical Laboratory, Tianjin Second People's Hospital, No.7 South Sudi Road, Nankai District, Tianjin, 300192, China
| | - Shuyue Zhang
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Yingzi Cai
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Junkai Huang
- Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, No.22 Qixiangtai Road, Heping District, Tianjin, 300070, China
| | - Jianbo Shu
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Ju Wang
- School of Biomedical Engineering, Tianjin Medical University, No. 22 Qixiangtai Road, Heping District, Tianjin, 300070, China.
| | - Chunquan Cai
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China.
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Dean B, Duce J, Li QX, Masters CL, Scarr E. Lower levels of soluble β-amyloid precursor protein, but not β-amyloid, in the frontal cortex in schizophrenia. Psychiatry Res 2024; 331:115656. [PMID: 38071879 DOI: 10.1016/j.psychres.2023.115656] [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: 08/18/2023] [Revised: 11/28/2023] [Accepted: 12/01/2023] [Indexed: 01/02/2024]
Abstract
We identified a sub-group (25%) of people with schizophrenia (muscarinic receptor deficit schizophrenia (MRDS)) that are characterised because of markedly lower levels of cortical muscarinic M1 receptors (CHRM1) compared to most people with the disorder (non-MRDS). Notably, bioinformatic analyses of our cortical gene expression data shows a disturbance in the homeostasis of a biochemical pathway that regulates levels of CHRM1. A step in this pathway is the processing of β-amyloid precursor protein (APP) and therefore we postulated there would be altered levels of APP in the frontal cortex from people with MRDS. Here we measure levels of CHRM1 using [3H]pirenzepine binding, soluble APP (sAPP) using Western blotting and amyloid beta peptides (Aβ1-40 and Aβ1-42) using ELISA in the frontal cortex (Brodmann's area 6: BA 6; MRDS = 14, non-MRDS = 14, controls = 14). We confirmed the MRDS cohort in this study had the expected low levels of [3H]pirenzepine binding. In addition, we showed that people with schizophrenia, independent of their sub-group status, had lower levels of sAPP compared to controls but did not have altered levels of Aβ1-40 or Aβ1-42. In conclusion, whilst changes in sAPP are not restricted to MRDS our data could indicate a role of APP, which is important in axonal and synaptic pruning, in the molecular pathology of the syndrome of schizophrenia.
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Affiliation(s)
- Brian Dean
- The Florey, Parkville, Victoria, Australia; The University of Melbourne of Melbourne Florey Department of Neuroscience and Mental Health, Parkville, Victoria, Australia.
| | - James Duce
- MSD Discovery Centre, 120 Moorgate, London, UK
| | - Qiao-Xin Li
- The Florey, Parkville, Victoria, Australia; The University of Melbourne of Melbourne Florey Department of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Colin L Masters
- The Florey, Parkville, Victoria, Australia; The University of Melbourne of Melbourne Florey Department of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Elizabeth Scarr
- The Department of Psychiatry, The University of Melbourne, Parkville, Victoria, Australia
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Dean B, Scarr E. Common changes in rat cortical gene expression after valproate or lithium treatment particularly affect pre- and post-synaptic pathways that regulate four neurotransmitters systems. World J Biol Psychiatry 2024; 25:54-64. [PMID: 37722808 DOI: 10.1080/15622975.2023.2258972] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/11/2023] [Indexed: 09/20/2023]
Abstract
OBJECTIVES We have postulated that common changes in gene expression after treatment with different therapeutic classes of psychotropic drugs contribute to their common therapeutic mechanisms of action. METHODS To test this hypothesis, we measured levels of cortical coding and non-coding RNA using GeneChip® Rat Exon 1.0 ST Array after treatment with vehicle (chow only), chow containing 1.8 g lithium carbonate/kg (n = 10) or chow containing 12 g sodium valproate/kg (n = 10) for 28 days. Differences in levels of RNA were identified using JMP Genomics 13 and the Panther Gene Ontology Classification System was used to identify potential consequences of RNA. RESULTS Compared to vehicle treatment, levels of cortical RNA for 543 and 583 coding and non-coding RNAs were different after treatment with valproate and lithium, respectively. Moreover, levels of 323 coding and non-coding RNAs were altered in a highly correlated way by treatment with valproate and lithium, changes that would impact on cholinergic, glutamatergic, serotonergic and dopaminergic neurotransmission as well as on voltage gated ion channels. CONCLUSIONS Our study suggests that treating with mood stabilisers cause many common changes in levels of RNA which will impact on CNS function, particularly affecting post-synaptic muscarinic receptor functioning and the release of multiple neurotransmitters.
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Affiliation(s)
- Brian Dean
- The Molecular Psychiatry Laboratory, The Florey Institute for Neuroscience and Mental Health, Parkville, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Elizabeth Scarr
- The Department of Psychiatry, The University of Melbourne, Parkville, Victoria, Australia
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Dean B. Muscarinic M1 and M4 receptor agonists for schizophrenia: promising candidates for the therapeutic arsenal. Expert Opin Investig Drugs 2023; 32:1113-1121. [PMID: 37994870 DOI: 10.1080/13543784.2023.2288074] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 11/22/2023] [Indexed: 11/24/2023]
Abstract
INTRODUCTION Successful phase 3 trials of KarXT in people with schizophrenia herald a new era of treating the disorder with drugs that do not target the dopamine D2 receptor. The active component of KarXT is xanomeline, a muscarinic (CHRM) M1 and M4 agonist, making muscarinic receptors a viable target for treating schizophrenia. AREAS COVERED This review covers the process of taking drugs that activate the muscarinic M1 and M4 receptors from conceptualization to the clinic and details the mechanisms by which activating the CHRM1 and 4 can affect the broad spectrum of symptoms experienced by people with schizophrenia. EXPERT OPINION Schizophrenia is a syndrome which means drugs that activate muscarinic M1 and M4 receptors, as was the case for antipsychotic drugs acting on the dopamine D2 receptor, will not give optimal outcomes in everyone within the syndrome. Thus, it would be ideal to identify people who are responsive to drugs activating the CHRM1 and 4. Given knowledge of the actions of these receptors, it is possible treatment non-response could be restricted to sub-groups within the syndrome who have deficits in cortical CHRM1 or those with one of the cognitive endophenotypes that may be identifiable by changes in the blood transcriptome.
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Affiliation(s)
- Brian Dean
- The Synaptic Biology and Cognition Laboratory, The Florey, Parkville, Victoria, Australia
- Florey Department of Neuroscience and Mental Health, Parkville, Victoria, Australia
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Sabbir MG, Swanson M, Albensi BC. Loss of cholinergic receptor muscarinic 1 impairs cortical mitochondrial structure and function: implications in Alzheimer's disease. Front Cell Dev Biol 2023; 11:1158604. [PMID: 37274741 PMCID: PMC10233041 DOI: 10.3389/fcell.2023.1158604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 05/04/2023] [Indexed: 06/06/2023] Open
Abstract
Introduction: Cholinergic Receptor Muscarinic 1 (CHRM1) is a G protein-coupled acetylcholine (ACh) receptor predominantly expressed in the cerebral cortex. In a retrospective postmortem brain tissues-based study, we demonstrated that severely (≥50% decrease) reduced CHRM1 proteins in the temporal cortex of Alzheimer's patients significantly correlated with poor patient outcomes. The G protein-mediated CHRM1 signal transduction cannot sufficiently explain the mechanistic link between cortical CHRM1 loss and the appearance of hallmark Alzheimer's pathophysiologies, particularly mitochondrial structural and functional abnormalities. Therefore, the objective of this study was to analyze the molecular, ultrastructural, and functional properties of cortical mitochondria using CHRM1 knockout (Chrm1-/-) and wild-type mice to identify mitochondrial abnormalities. Methods: Isolated and enriched cortical mitochondrial fractions derived from wild-type and Chrm1-/- mice were assessed for respiratory deficits (oxygen consumption) following the addition of different substrates. The supramolecular assembly of mitochondrial oxidative phosphorylation (OXPHOS)-associated protein complexes (complex I-V) and cortical mitochondrial ultrastructure were investigated by blue native polyacrylamide gel electrophoresis and transmission electron microscopy (TEM), respectively. A cocktail of antibodies, specific to Ndufb8, Sdhb, Uqcrc2, Mtco1, and Atp5a proteins representing different subunits of complexes I-V, respectively was used to characterize different OXPHOS-associated protein complexes. Results: Loss of Chrm1 led to a significant reduction in cortical mitochondrial respiration (oxygen consumption) concomitantly associated with reduced oligomerization of ATP synthase (complex V) and supramolecular assembly of complexes I-IV (Respirasome). Overexpression of Chrm1 in transformed cells (lacking native Chrm1) significantly increased complex V oligomerization and respirasome assembly leading to enhanced respiration. TEM analysis revealed that Chrm1 loss led to mitochondrial ultrastructural defects and alteration in the tinctorial properties of cortical neurons causing a significant increase in the abundance of dark cortical neurons (Chrm1-/- 85% versus wild-type 2%). Discussion: Our findings indicate a hitherto unknown effect of Chrm1 deletion in cortical neurons affecting mitochondrial function by altering multiple interdependent factors including ATP synthase oligomerization, respirasome assembly, and mitochondrial ultrastructure. The appearance of dark neurons in Chrm1-/- cortices implies potentially enhanced glutamatergic signaling in pyramidal neurons under Chrm1 loss condition. The findings provide novel mechanistic insights into Chrm1 loss with the appearance of mitochondrial pathophysiological deficits in Alzheimer's disease.
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Affiliation(s)
- Mohammad Golam Sabbir
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
- Alzo Biosciences Inc, SanDiego, CA, United States
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
- Barry & Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, United States
| | - Mamiko Swanson
- Alzo Biosciences Inc, SanDiego, CA, United States
- Barry & Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, United States
| | - Benedict C. Albensi
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
- Barry & Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, United States
- Department of Pharmacology & Therapeutics, University of Manitoba, Winnipeg, MB, Canada
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Dean B, Haroutunian V, Scarr E. Lower levels of cortical [ 3H]pirenzepine binding to postmortem tissue defines a sub-group of older people with schizophrenia with less severe cognitive deficits. Schizophr Res 2023; 255:274-282. [PMID: 37079947 DOI: 10.1016/j.schres.2023.03.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 02/15/2023] [Accepted: 03/18/2023] [Indexed: 04/22/2023]
Abstract
Multiple lines of evidence argue for lower levels of cortical muscarinic M1 receptors (CHRM1) in people with schizophrenia which is possibly due to a sub-group within the disorder who have a marked loss of CHRM1 (muscarinic receptor deficit sub-group (MRDS)). In this study we sought to determine if the lower levels of CHRM1 was apparent in older people with schizophrenia and whether the loss of CHRM1 was associated with symptom severity by measuring levels of cortical [3H]pirenzepine binding to CHRM1 from 56 people with schizophrenia and 43 controls. Compared to controls (173 ± 6.3 fmol / mg protein), there were lower levels of cortical [3H]pirenzepine binding in the people with schizophrenia (mean ± SEM: 153 ± 6.0 fmol / mg protein; p = 0.02; Cohen's d = - 0.46). [3H]pirenzepine binding in the people with schizophrenia, but not controls, was not normally distributed and best fitted a two-population solution. The nadir of binding separating the two groups of people with schizophrenia was 121 fmol / mg protein and levels of [3H]pirenzepine binding below this value had a 90.7 % specificity for the disorder. Compared to controls, the score from the Clinical Dementia Rating Scale (CDR) did not differ significantly in MRDS but were significantly higher in the sub-group with normal radioligand binding. Positive and Negative Syndrome Scale scores did not differ between the two sub-groups with schizophrenia. Our current study replicates and earlier finding showing a MRDS within schizophrenia and, for the first time, suggest this sub-group have less severe cognitive deficits others with schizophrenia.
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Affiliation(s)
- Brian Dean
- The Synaptic Biology and Cognition Laboratory, The Florey Institute for Neuroscience and Mental Health, Parkville, Victoria, Australia; Florey Department of Neuroscience and Mental Health, the University of Melbourne, Parkville, Victoria, Australia.
| | - Vahram Haroutunian
- Departments of Psychiatry and Neuroscience, The Icahn School of Medicine at Mount Sinai, New York, NY, USA; The Mental Illness Research, Education and Clinical Centers, JJ Peters VA Medical Center, Bronx, NY, USA
| | - Elizabeth Scarr
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
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Camci M, Karali N. Bioisosterism: 1,2,4-Oxadiazole Rings. ChemMedChem 2023; 18:e202200638. [PMID: 36772857 DOI: 10.1002/cmdc.202200638] [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: 11/23/2022] [Revised: 02/10/2023] [Accepted: 02/10/2023] [Indexed: 02/12/2023]
Abstract
Although studies in drug discovery have gained momentum in recent years, the conversion of drugs in use today into less toxic derivatives with pharmacologically superior properties is still of great importance in drug research. Bioisosterism facilitates the conversion of drugs into derivatives that present more positive pharmacological and toxicological profiles by changing existing groups in the drug structure within the framework of certain criteria that have been expanded today. The 1,2,4-oxadiazole ring is used as a bioisostere for ester and amide groups due to its resistance to hydrolysis. However, this ring is not limited to esters and amides, but can also be used as a bioisostere for other functional groups. In this review, cases in which the 1,2,4-oxadiazole ring is used as a bioisostere for various functional groups are discussed. Herein we shed light on 1,2,4-oxadiazole bioisosterism in the development of new drug candidates and in enhancing the pharmacological profiles of currently available drugs.
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Affiliation(s)
- Merve Camci
- Istanbul University, Faculty of Pharmacy Department of Pharmaceutical Chemistry, 34134 Beyazıt, Istanbul, Turkey
| | - Nilgün Karali
- Istanbul University, Faculty of Pharmacy Department of Pharmaceutical Chemistry, 34134 Beyazıt, Istanbul, Turkey
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Dean B, Bakker G, Ueda HR, Tobin AB, Brown A, Kanaan RAA. A growing understanding of the role of muscarinic receptors in the molecular pathology and treatment of schizophrenia. Front Cell Neurosci 2023; 17:1124333. [PMID: 36909280 PMCID: PMC9992992 DOI: 10.3389/fncel.2023.1124333] [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: 12/15/2022] [Accepted: 02/06/2023] [Indexed: 02/24/2023] Open
Abstract
Pre-clinical models, postmortem and neuroimaging studies all support a role for muscarinic receptors in the molecular pathology of schizophrenia. From these data it was proposed that activation of the muscarinic M1 and/or M4 receptor would reduce the severity of the symptoms of schizophrenia. This hypothesis is now supported by results from two clinical trials which indicate that activating central muscarinic M1 and M4 receptors can reduce the severity of positive, negative and cognitive symptoms of the disorder. This review will provide an update on a growing body of evidence that argues the muscarinic M1 and M4 receptors have critical roles in CNS functions that are dysregulated by the pathophysiology of schizophrenia. This realization has been made possible, in part, by the growing ability to visualize and quantify muscarinic M1 and M4 receptors in the human CNS using molecular neuroimaging. We will discuss how these advances have provided evidence to support the notion that there is a sub-group of patients within the syndrome of schizophrenia that have a unique molecular pathology driven by a marked loss of muscarinic M1 receptors. This review is timely, as drugs targeting muscarinic receptors approach clinical use for the treatment of schizophrenia and here we outline the background biology that supported development of such drugs to treat the disorder.
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Affiliation(s)
- Brian Dean
- Synaptic Biology and Cognition Laboratory, The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | | | - Hiroki R Ueda
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research, Osaka, Japan
| | - Andrew B Tobin
- Advanced Research Centre (ARC), School of Molecular Bioscience, University of Glasgow, Glasgow, United Kingdom
| | | | - Richard A A Kanaan
- Department of Psychiatry, Austin Health, The University of Melbourne, Heidelberg, VIC, Australia
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