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Burrack N, Yitzhaky A, Mizrahi L, Wang M, Stern S, Hertzberg L. Altered Expression of PDE4 Genes in Schizophrenia: Insights from a Brain and Blood Sample Meta-Analysis and iPSC-Derived Neurons. Genes (Basel) 2024; 15:609. [PMID: 38790238 PMCID: PMC11121586 DOI: 10.3390/genes15050609] [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: 06/04/2023] [Revised: 05/03/2024] [Accepted: 05/05/2024] [Indexed: 05/26/2024] Open
Abstract
Schizophrenia symptomatology includes negative symptoms and cognitive impairment. Several studies have linked schizophrenia with the PDE4 family of enzymes due to their genetic association and function in cognitive processes such as long-term potentiation. We conducted a systematic gene expression meta-analysis of four PDE4 genes (PDE4A-D) in 10 brain sample datasets (437 samples) and three blood sample datasets (300 samples). Subsequently, we measured mRNA levels in iPSC-derived hippocampal dentate gyrus neurons generated from fibroblasts of three groups: healthy controls, healthy monozygotic twins (MZ), and their MZ siblings with schizophrenia. We found downregulation of PDE4B in brain tissues, further validated by independent data of the CommonMind consortium (515 samples). Interestingly, the downregulation signal was present in a subgroup of the patients, while the others showed no differential expression or even upregulation. Notably, PDE4A, PDE4B, and PDE4D exhibited upregulation in iPSC-derived neurons compared to healthy controls, whereas in blood samples, PDE4B was found to be upregulated while PDE4A was downregulated. While the precise mechanism and direction of altered PDE4 expression necessitate further investigation, the observed multilevel differential expression across the brain, blood, and iPSC-derived neurons compellingly suggests the involvement of PDE4 genes in the pathophysiology of schizophrenia.
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Affiliation(s)
- Nitzan Burrack
- Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel;
- Clinical Research Center, Soroka University Medical Center, Beer-Sheva 84101, Israel
| | - Assif Yitzhaky
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Liron Mizrahi
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3103301, Israel
| | - Meiyan Wang
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Shani Stern
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3103301, Israel
| | - Libi Hertzberg
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
- Shalvata Mental Health Center, Affiliated with the Faculty of Medicine, Tel-Aviv University, 13 Aliat Hanoar St., Hod Hasharon 45100, Israel
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2
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A role for endothelial NMDA receptors in the pathophysiology of schizophrenia. Schizophr Res 2022; 249:63-73. [PMID: 33189520 DOI: 10.1016/j.schres.2020.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 12/14/2022]
Abstract
Numerous genetic and postmortem studies link N-methyl-d-aspartate receptor (NMDAR) dysfunction with schizophrenia, forming the basis of the popular glutamate hypothesis. Neuronal NMDAR abnormalities are consistently reported from both basic and clinical experiments, however, non-neuronal cells also contain NMDARs, and are rarely, if ever, considered in the discussion of glutamate action in schizophrenia. We offer an examination of recent discoveries elucidating the actions and consequences of NMDAR activation in the neuroendothelium. While there has been mixed literature regarding blood flow alterations in the schizophrenia brain, in this review, we posit that some common findings may be explained by neuroendothelial NMDAR dysfunction. In particular, we emphasize that endothelial NMDARs are key mediators of neurovascular coupling, where increased neuronal activity leads to increased blood flow. Based on the broad conclusions that hypoperfusion is a neuroanatomical finding in schizophrenia, we discuss potential mechanisms by which endothelial NMDARs contribute to this disorder. We propose that endothelial NMDAR dysfunction can be a primary cause of neurovascular abnormalities in schizophrenia. Importantly, functional MRI studies using BOLD signal as a proxy for neuron activity should be considered in a new light if neurovascular coupling is impaired in schizophrenia. This review is the first to propose that NMDARs in non-excitable cells play a role in schizophrenia.
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3
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Elevated endogenous GDNF induces altered dopamine signalling in mice and correlates with clinical severity in schizophrenia. Mol Psychiatry 2022; 27:3247-3261. [PMID: 35618883 PMCID: PMC9708553 DOI: 10.1038/s41380-022-01554-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 11/08/2022]
Abstract
Presynaptic increase in striatal dopamine is the primary dopaminergic abnormality in schizophrenia, but the underlying mechanisms are not understood. Here, we hypothesized that increased expression of endogenous GDNF could induce dopaminergic abnormalities that resemble those seen in schizophrenia. To test the impact of GDNF elevation, without inducing adverse effects caused by ectopic overexpression, we developed a novel in vivo approach to conditionally increase endogenous GDNF expression. We found that a 2-3-fold increase in endogenous GDNF in the brain was sufficient to induce molecular, cellular, and functional changes in dopamine signalling in the striatum and prefrontal cortex, including increased striatal presynaptic dopamine levels and reduction of dopamine in prefrontal cortex. Mechanistically, we identified adenosine A2a receptor (A2AR), a G-protein coupled receptor that modulates dopaminergic signalling, as a possible mediator of GDNF-driven dopaminergic abnormalities. We further showed that pharmacological inhibition of A2AR with istradefylline partially normalised striatal GDNF and striatal and cortical dopamine levels in mice. Lastly, we found that GDNF levels are increased in the cerebrospinal fluid of first episode psychosis patients, and in post-mortem striatum of schizophrenia patients. Our results reveal a possible contributor for increased striatal dopamine signalling in a subgroup of schizophrenia patients and suggest that GDNF-A2AR crosstalk may regulate dopamine function in a therapeutically targetable manner.
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Jeffries CD, Perkins DO, Fournier M, Do KQ, Cuenod M, Khadimallah I, Domenici E, Addington J, Bearden CE, Cadenhead KS, Cannon TD, Cornblatt BA, Mathalon DH, McGlashan TH, Seidman LJ, Tsuang M, Walker EF, Woods SW. Networks of blood proteins in the neuroimmunology of schizophrenia. Transl Psychiatry 2018; 8:112. [PMID: 29875399 PMCID: PMC5990539 DOI: 10.1038/s41398-018-0158-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 04/06/2018] [Accepted: 04/15/2018] [Indexed: 02/05/2023] Open
Abstract
Levels of certain circulating cytokines and related immune system molecules are consistently altered in schizophrenia and related disorders. In addition to absolute analyte levels, we sought analytes in correlation networks that could be prognostic. We analyzed baseline blood plasma samples with a Luminex platform from 72 subjects meeting criteria for a psychosis clinical high-risk syndrome; 32 subjects converted to a diagnosis of psychotic disorder within two years while 40 other subjects did not. Another comparison group included 35 unaffected subjects. Assays of 141 analytes passed early quality control. We then used an unweighted co-expression network analysis to identify highly correlated modules in each group. Overall, there was a striking loss of network complexity going from unaffected subjects to nonconverters and thence to converters (applying standard, graph-theoretic metrics). Graph differences were largely driven by proteins regulating tissue remodeling (e.g. blood-brain barrier). In more detail, certain sets of antithetical proteins were highly correlated in unaffected subjects (e.g. SERPINE1 vs MMP9), as expected in homeostasis. However, for particular protein pairs this trend was reversed in converters (e.g. SERPINE1 vs TIMP1, being synthetical inhibitors of remodeling of extracellular matrix and vasculature). Thus, some correlation signals strongly predict impending conversion to a psychotic disorder and directly suggest pharmaceutical targets.
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Affiliation(s)
- Clark D Jeffries
- Renaissance Computing Institute, University of North Carolina, Chapel Hill, NC, USA.
| | - Diana O Perkins
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - Margot Fournier
- Department of Psychiatry, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Kim Q Do
- Department of Psychiatry, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Michel Cuenod
- Department of Psychiatry, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Ines Khadimallah
- Department of Psychiatry, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Enrico Domenici
- Laboratory of Neurogenomic Biomarkers, Centre for Integrative Biology, and Microsoft Research, Centre for Computational Systems Biology, University of Trento, Trento, Italy
| | - Jean Addington
- Hotchkiss Brain Institute, Department of Psychiatry, University of Calgary, Calgary, AB, Canada
| | - Carrie E Bearden
- Departments of Psychiatry and Biobehavioral Sciences and Psychology, UCLA, Los Angeles, CA, USA
| | | | - Tyrone D Cannon
- Department of Psychology, Yale University, New Haven, CT, USA
| | | | - Daniel H Mathalon
- Department of Psychiatry, UCSF and San Francisco VA Healthcare System, San Francisco, CA, USA
| | | | - Larry J Seidman
- Department of Psychiatry, Harvard Medical School at Beth Israel Deaconess Medical Center and Massachusetts General Hospital, Boston, MA, USA
| | - Ming Tsuang
- Department of Psychiatry, Center for Behavioral Genomics UCSD, San Diego, CA, USA
| | - Elaine F Walker
- Departments of Psychology and Psychiatry, Emory University, Atlanta, GA, USA
| | - Scott W Woods
- Department of Psychology, Yale University, New Haven, CT, USA
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5
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Jin LE, Wang M, Yang ST, Yang Y, Galvin VC, Lightbourne TC, Ottenheimer D, Zhong Q, Stein J, Raja A, Paspalas CD, Arnsten AFT. mGluR2/3 mechanisms in primate dorsolateral prefrontal cortex: evidence for both presynaptic and postsynaptic actions. Mol Psychiatry 2017; 22:1615-1625. [PMID: 27502475 PMCID: PMC5298940 DOI: 10.1038/mp.2016.129] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 05/04/2016] [Accepted: 06/15/2016] [Indexed: 01/12/2023]
Abstract
Cognitive deficits in psychiatric and age-related disorders generally involve dysfunction of the dorsolateral prefrontal cortex (dlPFC), but there are few treatments for these debilitating symptoms. Group II metabotropic glutamate receptors (mGluR2/3), which couple to Gi/Go, have been a focus of therapeutics based on rodent research, where mGluR2/3 have been shown to reduce axonal glutamate release and increase glial glutamate uptake. However, this strategy has had mixed results in patients, and understanding mGluR2/3 mechanisms in primates will help guide therapeutic interventions. The current study examined mGluR2/3 localization and actions in the primate dlPFC layer III circuits underlying working memory, where the persistent firing of 'Delay cells' is mediated by N-methyl-d-aspartate receptors and weakened by cAMP-PKA-potassium channel signaling in dendritic spines. Immunoelectron microscopy identified postsynaptic mGluR2/3 in the spines, in addition to the traditional presynaptic and astrocytic locations. In vivo iontophoretic application of the mGluR2/3 agonists (2R, 4R)-APDC or LY379268 onto dlPFC Delay cells produced an inverted-U effect on working memory representation, with enhanced neuronal firing following low doses of mGluR2/3 agonists. The enhancing effects were reversed by an mGluR2/3 antagonist or by activating cAMP signaling, consistent with mGluR2/3 inhibiting postsynaptic cAMP signaling in spines. Systemic administration of these agonists to monkeys performing a working memory task also produced an inverted-U dose-response, where low doses improved performance but higher doses, similar to clinical trials, had mixed effects. Our data suggest that low doses of mGluR2/3 stimulation may have therapeutic effects through unexpected postsynaptic actions in dlPFC, strengthening synaptic connections and improving cognitive function.
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Affiliation(s)
- L E Jin
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - M Wang
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - S-T Yang
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Y Yang
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - V C Galvin
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - T C Lightbourne
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - D Ottenheimer
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Q Zhong
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - J Stein
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - A Raja
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - C D Paspalas
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA,Department of Neuroscience, Yale School of Medicine, Yale University, 333 Cedar Street, New Haven, CT 06520, USA. E-mail: or
| | - A F T Arnsten
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA,Department of Neuroscience, Yale School of Medicine, Yale University, 333 Cedar Street, New Haven, CT 06520, USA. E-mail: or
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Howes OD, McCutcheon R, Owen MJ, Murray RM. The Role of Genes, Stress, and Dopamine in the Development of Schizophrenia. Biol Psychiatry 2017; 81:9-20. [PMID: 27720198 PMCID: PMC5675052 DOI: 10.1016/j.biopsych.2016.07.014] [Citation(s) in RCA: 326] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 07/08/2016] [Accepted: 07/10/2016] [Indexed: 02/06/2023]
Abstract
The dopamine hypothesis is the longest standing pathoetiologic theory of schizophrenia. Because it was initially based on indirect evidence and findings in patients with established schizophrenia, it was unclear what role dopamine played in the onset of the disorder. However, recent studies in people at risk of schizophrenia have found elevated striatal dopamine synthesis capacity and increased dopamine release to stress. Furthermore, striatal dopamine changes have been linked to altered cortical function during cognitive tasks, in line with preclinical evidence that a circuit involving cortical projections to the striatum and midbrain may underlie the striatal dopamine changes. Other studies have shown that a number of environmental risk factors for schizophrenia, such as social isolation and childhood trauma, also affect presynaptic dopaminergic function. Advances in preclinical work and genetics have begun to unravel the molecular architecture linking dopamine, psychosis, and psychosocial stress. Included among the many genes associated with risk of schizophrenia are the gene encoding the dopamine D2 receptor and those involved in the upstream regulation of dopaminergic synthesis, through glutamatergic and gamma-aminobutyric acidergic pathways. A number of these pathways are also linked to the stress response. We review these new lines of evidence and present a model of how genes and environmental factors may sensitize the dopamine system so that it is vulnerable to acute stress, leading to progressive dysregulation and the onset of psychosis. Finally, we consider the implications for rational drug development, in particular regionally selective dopaminergic modulation, and the potential of genetic factors to stratify patients.
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Affiliation(s)
- Oliver D Howes
- Psychosis Studies, King's College London, London, United Kingdom; MRC Clinical Sciences Centre, Imperial College Hammersmith Hospital, London, United Kingdom.
| | - Robert McCutcheon
- Psychosis Studies, King's College London, London, United Kingdom; MRC Clinical Sciences Centre, Imperial College Hammersmith Hospital, London, United Kingdom
| | - Michael J Owen
- MRC Centre for Neuropsychiatric Genetics and Genomics, and Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, Wales, United Kingdom
| | - Robin M Murray
- Psychosis Studies, King's College London, London, United Kingdom
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7
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Hoirisch-Clapauch S, Amaral OB, Mezzasalma MAU, Panizzutti R, Nardi AE. Dysfunction in the coagulation system and schizophrenia. Transl Psychiatry 2016; 6:e704. [PMID: 26731441 PMCID: PMC5068878 DOI: 10.1038/tp.2015.204] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 10/22/2015] [Accepted: 10/26/2015] [Indexed: 01/24/2023] Open
Abstract
Although different hypotheses have been formulated to explain schizophrenia pathogenesis, the links between them are weak. The observation that five psychotic patients on chronic warfarin therapy for deep-vein thrombosis showed long-term remission of psychotic symptoms made us suspect that abnormalities in the coagulation pathway, specifically low tissue plasminogen activator (tPA) activity, could be one of the missing links. Our hypothesis is supported by a high prevalence of conditions affecting tPA activity in drug-naive schizophrenia, such as antiphospholipid antibodies, elevated cytokine levels, hyperinsulinemia and hyperhomocysteinemia. We recently screened a group of schizophrenia patients and controls for conditions affecting tPA activity. Free-protein S deficiency was highly prevalent among patients, but not found in controls. Free-protein S and functional protein C are natural anticoagulants that form complexes that inhibit tPA inhibitors. All participants had normal protein C levels, suggesting that protein S could have a role in schizophrenia, independent of protein C. Chronic patients and those studied during acute episodes had between three and six conditions affecting tPA and/or protein S activity, while patients in remission had up to two, which led us to postulate that multiple conditions affecting tPA and/or protein S activity could contribute to the full expression of schizophrenia phenotype. This paper describes the physiological roles of tPA and protein S, reviewing how their activity influences pathogenesis and comorbidity of schizophrenia. Next, it analyzes how activity of tPA and protein S is influenced by biochemical abnormalities found in schizophrenia. Last, it suggests future directions for research, such as studies on animal models and on therapeutic approaches for schizophrenia aiming at increasing tPA and protein S activity.
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Affiliation(s)
- S Hoirisch-Clapauch
- Department of Hematology, Hospital Federal dos Servidores do Estado, Ministry of Health, Rio de Janeiro, Brazil
| | - O B Amaral
- Department of Medical Biochemistry, Medical Biochemistry Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - M A U Mezzasalma
- Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute for Translational Medicine, Instituto Nacional de Ciência e Tecnologia - Translacional em Medicina, Rio de Janeiro, Brazil
| | - R Panizzutti
- Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Basic-Clinical Neuroscience Program, Biomedical Sciences Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - A E Nardi
- Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute for Translational Medicine, Instituto Nacional de Ciência e Tecnologia - Translacional em Medicina, Rio de Janeiro, Brazil
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8
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Arnsten AFT. Stress weakens prefrontal networks: molecular insults to higher cognition. Nat Neurosci 2015; 18:1376-85. [PMID: 26404712 DOI: 10.1038/nn.4087] [Citation(s) in RCA: 418] [Impact Index Per Article: 46.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/15/2015] [Indexed: 12/13/2022]
Abstract
A variety of cognitive disorders are worsened by stress exposure and involve dysfunction of the newly evolved prefrontal cortex (PFC). Exposure to acute, uncontrollable stress increases catecholamine release in PFC, reducing neuronal firing and impairing cognitive abilities. High levels of noradrenergic α1-adrenoceptor and dopaminergic D1 receptor stimulation activate feedforward calcium-protein kinase C and cyclic AMP-protein kinase A signaling, which open potassium channels to weaken synaptic efficacy in spines. In contrast, high levels of catecholamines strengthen the primary sensory cortices, amygdala and striatum, rapidly flipping the brain from reflective to reflexive control of behavior. These mechanisms are exaggerated by chronic stress exposure, where architectural changes lead to persistent loss of PFC function. Understanding these mechanisms has led to the successful translation of prazosin and guanfacine for treating stress-related disorders. Dysregulation of stress signaling pathways by genetic insults likely contributes to PFC deficits in schizophrenia, while age-related insults initiate interacting vicious cycles that increase vulnerability to Alzheimer's degeneration.
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Affiliation(s)
- Amy F T Arnsten
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, USA
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Weng X, Zhou D, Liu F, Zhang H, Ye J, Zhang Z, Zhang D, Wang Y, Tao L, Cao L, Kan M, Wang T, Feng G, Qin X, Sun J, He L, Liu Y. DNA methylation profiling in the thalamus and hippocampus of postnatal malnourished mice, including effects related to long-term potentiation. BMC Neurosci 2014; 15:31. [PMID: 24555847 PMCID: PMC3941971 DOI: 10.1186/1471-2202-15-31] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 02/11/2014] [Indexed: 02/06/2023] Open
Abstract
Background DNA methylation has been viewed as the most highly characterized epigenetic mark for genome regulation and development. Postnatal brains appear to exhibit stimulus-induced methylation changes because of factors such as environment, lifestyle, and diet (nutrition). The purpose of this study was to examine how extensively the brain DNA methylome is regulated by nutrition in early life. Results By quantifying the total amount of 5-methylcytosine (5mC) in the thalamus and the hippocampus of postnatal malnourished mice and normal mice, we found the two regions showed differences in global DNA methylation status. The methylation level in the thalamus was much higher than that in the hippocampus. Then, we used a next-generation sequencing (NGS)-based method (MSCC) to detect the whole genome methylation of the two regions in malnourished mice and normal mice. Notably, we found that in the thalamus, 500 discriminable variations existed and that approximately 60% were related to neuronal development or psychiatric diseases. Pathway analyses of the corresponding genes highlighted changes for 9 genes related to long-term potentiation (5.3-fold enrichment, P = 0.033). Conclusions Our findings may help to indicate the genome-wide DNA methylation status of different brain regions and the effects of malnutrition on brain DNA methylation. The results also indicate that postnatal malnutrition may increase the risk of psychiatric disorders.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Lin He
- Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, PR China.
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Arnsten AFT, Jin LE. Molecular influences on working memory circuits in dorsolateral prefrontal cortex. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 122:211-31. [PMID: 24484703 DOI: 10.1016/b978-0-12-420170-5.00008-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The working memory circuits of the primate dorsolateral prefrontal cortex (dlPFC) are modulated in a unique manner, often opposite to the molecular mechanisms needed for long-term memory consolidation. Working memory, our "mental sketch pad" is an ephemeral process, whereby transient, mental representations form the foundation for abstract thought. The microcircuits that generate mental representations are found in deep layer III of the dlPFC, where pyramidal cells excite each other to keep information "in mind" through NMDA receptor synapses on spines. The catecholaminergic and cholinergic arousal systems have rapid and flexible influences on the strength of these connections, thus allowing coordination between arousal and cognitive states. These modulators can rapidly weaken connectivity, for example, as occurs during uncontrollable stress, via feedforward calcium-cAMP signaling opening potassium (K(+)) channels near synapses on spines. Lower levels of calcium-cAMP-K(+) channel signaling provide negative feedback within recurrent excitatory circuits, and help to gate inputs to shape the contents of working memory. There are also explicit mechanisms to inhibit calcium-cAMP signaling and strengthen connectivity, for example, postsynaptic α2A-adrenoceptors on spines. This work has led to the development of the α2A agonist, guanfacine, for the treatment of a variety of dlPFC disorders. In mental illness, there are a variety of genetic insults to the molecules that normally serve to inhibit calcium-cAMP signaling in spines, thus explaining why so many genetic insults can lead to the same phenotype of impaired dlPFC cognitive function. Thus, the molecular mechanisms that provide mental flexibility may also confer vulnerability when dysregulated in cognitive disorders.
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Affiliation(s)
- Amy F T Arnsten
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Lu E Jin
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, USA
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11
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Cocchi E, Drago A, de Ronchi D, Serretti A. The genetics of vascular incidents associated with second-generation antipsychotic administration. Expert Rev Clin Pharmacol 2013; 7:75-90. [PMID: 24325740 DOI: 10.1586/17512433.2014.865515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Second-generation antipsychotics (SGA) have been associated with risk of stroke in elderly patients, but the molecular and genetic background under this association has been poorly investigated. The aim of the present study was to prioritize a list of genes with an SGA altered expression in order to characterize the genetic background of the SGA-associated stroke risk. Genes with evidence of an altered expression after SGA treatments in genome-wide investigations, both in animals and men, were identified. The Genetic Association Database (GAD) served to verify which of these genes had a proven positive association with an increased stroke risk, and along with it each evidence was tested and recorded. Seven hundred and forty five genes had evidence of a change of their expression profile after SGA administration in various studies. Nine out of them have also been significantly related to an increased strokes risk. We identified and described nine genes as potential candidates for future genetic studies aimed at identifying the genetic background of the SGA-related stroke risk. Further, we identify the molecular pathways in which these genes operate in order to provide a molecular framework to understand on which basis SGA may enhance the risk for stroke.
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Affiliation(s)
- Enrico Cocchi
- Department of Biomedical and NeuroMotor Sciences, University of Bologna, Italy
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12
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Arnsten AFT, Wang MJ, Paspalas CD. Neuromodulation of thought: flexibilities and vulnerabilities in prefrontal cortical network synapses. Neuron 2012; 76:223-39. [PMID: 23040817 PMCID: PMC3488343 DOI: 10.1016/j.neuron.2012.08.038] [Citation(s) in RCA: 384] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2012] [Indexed: 12/26/2022]
Abstract
This review describes unique neuromodulatory influences on working memory prefrontal cortical (PFC) circuits that coordinate cognitive strength with arousal state. Working memory arises from recurrent excitation within layer III PFC pyramidal cell NMDA circuits, which are afflicted in aging and schizophrenia. Neuromodulators rapidly and flexibly alter the efficacy of these synaptic connections, while leaving the synaptic architecture unchanged, a process called dynamic network connectivity (DNC). Increases in calcium-cAMP signaling open ion channels in long, thin spines, gating network connections. Inhibition of calcium-cAMP signaling by stimulating α2A-adrenoceptors on spines strengthens synaptic efficacy and increases network firing, whereas optimal stimulation of dopamine D1 receptors sculpts network inputs to refine mental representation. Generalized increases in calcium-cAMP signaling during fatigue or stress disengage dlPFC recurrent circuits, reduce firing and impair top-down cognition. Impaired DNC regulation contributes to age-related cognitive decline, while genetic insults to DNC proteins are commonly linked to schizophrenia.
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Affiliation(s)
- Amy F T Arnsten
- Department of Neurobiology, Yale Medical School, New Haven, CT 06510, USA.
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13
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Bosker FJ, Gladkevich AV, Pietersen CY, Kooi KA, Bakker PL, Gerbens F, den Boer JA, Korf J, te Meerman G. Comparison of brain and blood gene expression in an animal model of negative symptoms in schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2012; 38:142-8. [PMID: 22763037 DOI: 10.1016/j.pnpbp.2012.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 03/05/2012] [Accepted: 03/06/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVES To investigate the potential of white blood cells as probes for central processes we have measured gene expression in both the anterior cingulate cortex and white blood cells using a putative animal model of negative symptoms in schizophrenia. METHODS The model is based on the capability of ketamine to induce psychotic symptoms in healthy volunteers and to worsen such symptoms in schizophrenic patients. Classical fear conditioning is used to assess emotional processing and cognitive function in animals exposed to sub-chronic ketamine vs. controls. Gene expression was measured using a commercially sourced whole genome rat gene array. Data analyses were performed using ANOVA (Systat 11). RESULTS In both anterior cingulate cortex and white blood cells a significant interaction between ketamine and fear conditioning could be observed. The outcome is largely supported by our subsequent metagene analysis. Moreover, the correlation between gene expression in brain and blood is about constant when no ketamine is present (r~0.4). With ketamine, however, the correlation becomes very low (r~0.2) when there is no fear, but it increases to ~0.6 when fear and ketamine are both present. Our results show that under normal conditions ketamine lowers gene expression in the brain, but this effect is completely reversed in combination with fear conditioning, indicating a stimulatory action. CONCLUSION This paradoxical outcome indicates that extreme care must be taken when using gene expression data from white blood cells as marker for psychiatric disorders, especially when pharmacological and environmental interactions are at play.
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Affiliation(s)
- Fokko J Bosker
- University Centre of Psychiatry, University Medical Centre Groningen, University of Groningen, The Netherlands.
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Wu JQ, Wang X, Beveridge NJ, Tooney PA, Scott RJ, Carr VJ, Cairns MJ. Transcriptome sequencing revealed significant alteration of cortical promoter usage and splicing in schizophrenia. PLoS One 2012; 7:e36351. [PMID: 22558445 PMCID: PMC3338678 DOI: 10.1371/journal.pone.0036351] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 04/03/2012] [Indexed: 12/21/2022] Open
Abstract
Background While hybridization based analysis of the cortical transcriptome has provided important insight into the neuropathology of schizophrenia, it represents a restricted view of disease-associated gene activity based on predetermined probes. By contrast, sequencing technology can provide un-biased analysis of transcription at nucleotide resolution. Here we use this approach to investigate schizophrenia-associated cortical gene expression. Methodology/Principal Findings The data was generated from 76 bp reads of RNA-Seq, aligned to the reference genome and assembled into transcripts for quantification of exons, splice variants and alternative promoters in postmortem superior temporal gyrus (STG/BA22) from 9 male subjects with schizophrenia and 9 matched non-psychiatric controls. Differentially expressed genes were then subjected to further sequence and functional group analysis. The output, amounting to more than 38 Gb of sequence, revealed significant alteration of gene expression including many previously shown to be associated with schizophrenia. Gene ontology enrichment analysis followed by functional map construction identified three functional clusters highly relevant to schizophrenia including neurotransmission related functions, synaptic vesicle trafficking, and neural development. Significantly, more than 2000 genes displayed schizophrenia-associated alternative promoter usage and more than 1000 genes showed differential splicing (FDR<0.05). Both types of transcriptional isoforms were exemplified by reads aligned to the neurodevelopmentally significant doublecortin-like kinase 1 (DCLK1) gene. Conclusions This study provided the first deep and un-biased analysis of schizophrenia-associated transcriptional diversity within the STG, and revealed variants with important implications for the complex pathophysiology of schizophrenia.
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Affiliation(s)
- Jing Qin Wu
- Schizophrenia Research Institute, Sydney, Australia
- School of Biomedical Sciences and Pharmacy, Faculty of Health, Priority Research Centre for Translational Neuroscience and Mental Health, The University of Newcastle, New South Wales, Australia
- Hunter Medical Research Institute, New Lambton, New South Wales, Australia
| | - Xi Wang
- School of Biomedical Sciences and Pharmacy, Faculty of Health, Priority Research Centre for Translational Neuroscience and Mental Health, The University of Newcastle, New South Wales, Australia
- Hunter Medical Research Institute, New Lambton, New South Wales, Australia
| | - Natalie J. Beveridge
- Schizophrenia Research Institute, Sydney, Australia
- School of Biomedical Sciences and Pharmacy, Faculty of Health, Priority Research Centre for Translational Neuroscience and Mental Health, The University of Newcastle, New South Wales, Australia
- Hunter Medical Research Institute, New Lambton, New South Wales, Australia
| | - Paul A. Tooney
- Schizophrenia Research Institute, Sydney, Australia
- School of Biomedical Sciences and Pharmacy, Faculty of Health, Priority Research Centre for Translational Neuroscience and Mental Health, The University of Newcastle, New South Wales, Australia
- Hunter Medical Research Institute, New Lambton, New South Wales, Australia
| | - Rodney J. Scott
- School of Biomedical Sciences and Pharmacy, Faculty of Health, Priority Research Centre for Translational Neuroscience and Mental Health, The University of Newcastle, New South Wales, Australia
- Hunter Medical Research Institute, New Lambton, New South Wales, Australia
| | - Vaughan J. Carr
- Schizophrenia Research Institute, Sydney, Australia
- Research Unit for Schizophrenia Epidemiology, School of Psychiatry, University of New South Wales, St. Vincent's Hospital, Darlinghurst, New South Wales, Australia
| | - Murray J. Cairns
- Schizophrenia Research Institute, Sydney, Australia
- School of Biomedical Sciences and Pharmacy, Faculty of Health, Priority Research Centre for Translational Neuroscience and Mental Health, The University of Newcastle, New South Wales, Australia
- Hunter Medical Research Institute, New Lambton, New South Wales, Australia
- * E-mail:
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