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Evidence that the pituitary gland connects type 2 diabetes mellitus and schizophrenia based on large-scale trans-ethnic genetic analyses. J Transl Med 2022; 20:501. [PMID: 36329495 PMCID: PMC9632150 DOI: 10.1186/s12967-022-03704-0] [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: 08/30/2022] [Revised: 10/05/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Previous studies on European (EUR) samples have obtained inconsistent results regarding the genetic correlation between type 2 diabetes mellitus (T2DM) and Schizophrenia (SCZ). A large-scale trans-ethnic genetic analysis may provide additional evidence with enhanced power. OBJECTIVE We aimed to explore the genetic basis for both T2DM and SCZ based on large-scale genetic analyses of genome-wide association study (GWAS) data from both East Asian (EAS) and EUR subjects. METHODS A range of complementary approaches were employed to cross-validate the genetic correlation between T2DM and SCZ at the whole genome, autosomes (linkage disequilibrium score regression, LDSC), loci (Heritability Estimation from Summary Statistics, HESS), and causal variants (MiXeR and Mendelian randomization, MR) levels. Then, genome-wide and transcriptome-wide cross-trait/ethnic meta-analyses were performed separately to explore the effective shared organs, cells and molecular pathways. RESULTS A weak genome-wide negative genetic correlation between SCZ and T2DM was found for the EUR (rg = - 0.098, P = 0.009) and EAS (rg =- 0.053 and P = 0.032) populations, which showed no significant difference between the EUR and EAS populations (P = 0.22). After Bonferroni correction, the rg remained significant only in the EUR population. Similar results were obtained from analyses at the levels of autosomes, loci and causal variants. 25 independent variants were firstly identified as being responsible for both SCZ and T2DM. The variants associated with the two disorders were significantly correlated to the gene expression profiles in the brain (P = 1.1E-9) and pituitary gland (P = 1.9E-6). Then, 61 protein-coding and non-coding genes were identified as effective genes in the pituitary gland (P < 9.23E-6) and were enriched in metabolic pathways related to glutathione mediated arsenate detoxification and to D-myo-inositol-trisphosphate. CONCLUSION Here, we show that a negative genetic correlation exists between SCZ and T2DM at the whole genome, autosome, locus and causal variant levels. We identify pituitary gland as a common effective organ for both diseases, in which non-protein-coding effective genes, such as lncRNAs, may be responsible for the negative genetic correlation. This highlights the importance of molecular metabolism and neuroendocrine modulation in the pituitary gland, which may be responsible for the initiation of T2DM in SCZ patients.
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Osuch E, Ursano R, Li H, Webster M, Hough C, Fullerton C, Leskin G. Brain Environment Interactions: Stress, Posttraumatic Stress Disorder, and the Need for a Postmortem Brain Collection. Psychiatry 2022; 85:113-145. [PMID: 35588486 DOI: 10.1080/00332747.2022.2068916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Stress, especially the extreme stress of traumatic events, can alter both neurobiology and behavior. Such extreme environmental situations provide a useful model for understanding environmental influences on human biology and behavior. This paper will review some of the evidence of brain alterations that occur with exposure to environmental stress. This will include recent studies using neuroimaging and will address the need for histological confirmation of imaging study results. We will review the current scientific approaches to understanding brain environment interactions, and then make the case for the collection and study of postmortem brain tissue for the advancement of our understanding of the effects of environment on the brain.Creating a brain tissue collection specifically for the investigation of the effects of extreme environmental stressors fills a gap in the current research; it will provide another of the important pieces to the puzzle that constitutes the scientific investigation of negative effects of environmental exposures. Such a resource will facilitate new discoveries related to the psychiatric illnesses of acute stress disorder and posttraumatic stress disorder, and can enable scientists to correlate structural and functional imaging findings with tissue abnormalities, which is essential to validate the results of recent imaging studies.
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Mueed Z, Mehta D, Rai PK, Kamal MA, Poddar NK. Cross-Interplay between Osmolytes and mTOR in Alzheimer's Disease Pathogenesis. Curr Pharm Des 2021; 26:4699-4711. [PMID: 32418522 DOI: 10.2174/1381612826666200518112355] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/15/2020] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease, categorized by the piling of amyloid-β (Aβ), hyperphosphorylated tau, PHFs, NFTs and mTOR hyperactivity, is a neurodegenerative disorder, affecting people across the globe. Osmolytes are known for osmoprotectants and play a pivotal role in protein folding, function and protein stability, thus, preventing proteins aggregation, and counteracting effects of denaturing solutes on proteins. Osmolytes (viz., sorbitol, inositol, and betaine) perform a pivotal function of maintaining homeostasis during hyperosmotic stress. The selective advantage of utilising osmolytes over inorganic ions by cells is in maintaining cell volume without compromising cell function, which is important for organs such as the brain. Osmolytes have been documented not only as neuroprotectors but they also seem to act as neurodegenerators. Betaine, sucrose and trehalose supplementation has been seen to induce autophagy thereby inhibiting the accumulation of Aβ. In contrast, sucrose has also been associated with mTOR hyperactivity, a hallmark of AD pathology. The neuroprotective action of taurine is revealed when taurine supplementation is seen to inhibit neural damage, apoptosis and oxidative damage. Inositol stereoisomers (viz., scyllo-inositol and myo-inositol) have also been seen to inhibit Aβ production and plaque formation in the brain, inhibiting AD pathogenesis. However, TMAO affects the aging process adversely by deregulating the mTOR signalling pathway and then kindling cognitive dysfunction via degradation of chemical synapses and synaptic plasticity. Thus, it can be concluded that osmolytes may act as a probable therapeutic approach for neurodevelopmental disorders. Here, we have reviewed and focussed upon the impact of osmolytes on mTOR signalling pathway and thereby its role in AD pathogenesis.
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Affiliation(s)
- Zeba Mueed
- Department of Biotechnology, Invertis University, Bareilly, Uttar Pradesh, India
| | - Devanshu Mehta
- Kusuma School of Biological Sciences, Indian Institute of Technology, Delhi, India
| | - Pankaj K Rai
- Department of Biotechnology, Invertis University, Bareilly, Uttar Pradesh, India
| | - Mohammad A Kamal
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia,Enzymoics; Novel Global Community Educational Foundation, 7 Peterlee Place, Hebersham, NSW 2770, Australia
| | - Nitesh K Poddar
- Department of Biosciences, Manipal University Jaipur, Rajasthan, India
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Watkins OC, Yong HEJ, Sharma N, Chan SY. A review of the role of inositols in conditions of insulin dysregulation and in uncomplicated and pathological pregnancy. Crit Rev Food Sci Nutr 2020; 62:1626-1673. [PMID: 33280430 DOI: 10.1080/10408398.2020.1845604] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Inositols, a group of 6-carbon polyols, are highly bioactive molecules derived from diet and endogenous synthesis. Inositols and their derivatives are involved in glucose and lipid metabolism and participate in insulin-signaling, with perturbations in inositol processing being associated with conditions involving insulin resistance, dysglycemia and dyslipidemia such as polycystic ovary syndrome and diabetes. Pregnancy is similarly characterized by substantial and complex changes in glycemic and lipidomic regulation as part of maternal adaptation and is also associated with physiological alterations in inositol processing. Disruptions in maternal adaptation are postulated to have a critical pathophysiological role in pregnancy complications such as gestational diabetes and pre-eclampsia. Inositol supplementation has shown promise as an intervention for the alleviation of symptoms in conditions of insulin resistance and for gestational diabetes prevention. However, the mechanisms behind these affects are not fully understood. In this review, we explore the role of inositols in conditions of insulin dysregulation and in pregnancy, and identify priority areas for research. We particularly examine the role and function of inositols within the maternal-placental-fetal axis in both uncomplicated and pathological pregnancies. We also discuss how inositols may mediate maternal-placental-fetal cross-talk, and regulate fetal growth and development, and suggest that inositols play a vital role in promoting healthy pregnancy.
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Affiliation(s)
- Oliver C Watkins
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Hannah E J Yong
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
| | - Neha Sharma
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Shiao-Yng Chan
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
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Kubota M, Moriguchi S, Takahata K, Nakajima S, Horita N. Treatment effects on neurometabolite levels in schizophrenia: A systematic review and meta-analysis of proton magnetic resonance spectroscopy studies. Schizophr Res 2020; 222:122-132. [PMID: 32505446 DOI: 10.1016/j.schres.2020.03.069] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 01/29/2020] [Accepted: 03/29/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Although there is growing evidence of alterations in the neurometabolite status associated with the pathophysiology of schizophrenia, how treatments influence these metabolite levels in patients with schizophrenia remains poorly studied. METHODS We conducted a literature search using Embase, Medline, and PsycINFO to identify proton magnetic resonance spectroscopy studies that compared neurometabolite levels before and after treatment in patients with schizophrenia. Six neurometabolites (glutamate, glutamine, glutamate + glutamine, gamma-aminobutyric acid, N-acetylaspartate, myo-inositol) and six regions of interest (frontal cortex, temporal cortex, parieto-occipital cortex, thalamus, basal ganglia, hippocampus) were investigated. RESULTS Thirty-two studies (n = 773 at follow-up) were included in our meta-analysis. Our results demonstrated that the frontal glutamate + glutamine level was significantly decreased (14 groups; n = 292 at follow-up; effect size = -0.35, P = 0.0003; I2 = 22%) and the thalamic N-acetylaspartate level was significantly increased (7 groups; n = 184 at follow-up; effect size = 0.47, P < 0.00001; I2 = 0%) after treatment in schizophrenia patients. No significant associations were found between neurometabolite changes and age, gender, duration of illness, duration of treatment, or baseline symptom severity. CONCLUSIONS The current results suggest that glutamatergic neurometabolite levels in the frontal cortex and neuronal integrity in the thalamus in schizophrenia might be modified following treatment.
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Affiliation(s)
- Manabu Kubota
- Department of Functional Brain Imaging, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Department of Psychiatry, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
| | - Sho Moriguchi
- Department of Functional Brain Imaging, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T1R8, Canada
| | - Keisuke Takahata
- Department of Functional Brain Imaging, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Department of Neuropsychiatry, Keio University Graduate School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Shinichiro Nakajima
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T1R8, Canada; Department of Neuropsychiatry, Keio University Graduate School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Nobuyuki Horita
- Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
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Jupp B, Sawiak SJ, van der Veen B, Lemstra S, Toschi C, Barlow RL, Pekcec A, Bretschneider T, Nicholson JR, Robbins TW, Dalley JW. Diminished Myoinositol in Ventromedial Prefrontal Cortex Modulates the Endophenotype of Impulsivity. Cereb Cortex 2020; 30:3392-3402. [PMID: 31897490 PMCID: PMC7197196 DOI: 10.1093/cercor/bhz317] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 11/24/2019] [Accepted: 11/28/2019] [Indexed: 02/02/2023] Open
Abstract
Maladaptive impulsivity manifests in a variety of disorders, including attention-deficit hyperactivity disorder (ADHD), depression, and substance use disorder. However, the etiological mechanisms of impulsivity remain poorly understood. In the present study, we used in-vivo proton magnetic resonance spectroscopy (1H-MRS) to investigate neurometabolite content in the prefrontal cortex (PFC) and striatum of rats exhibiting low- versus high-impulsive (LI, HI) behavior on a visual attentional task. We validated our 1H-MRS findings using regionally resolved ex-vivo mass spectroscopy, transcriptomics, and site-directed RNA interference in the ventromedial PFC. We report a significant reduction in myoinositol levels in the PFC but not the striatum of HI rats compared with LI rats. Reduced myoinositol content was localized to the infralimbic (IL) cortex, where significant reductions in transcript levels of key proteins involved in the synthesis and recycling of myoinositol (IMPase1) were also present. Knockdown of IMPase1in the IL cortex increased impulsivity in nonimpulsive rats when the demand on inhibitory response control was increased. We conclude that diminished myoinositol levels in ventromedial PFC causally mediate a specific form of impulsivity linked to vulnerability for stimulant addiction in rodents. Myoinositol and related signaling substrates may thus offer novel opportunities for treating neuropsychiatric disorders comorbid with impulsive symptomology.
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Affiliation(s)
- Bianca Jupp
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
| | - Steve J Sawiak
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | | | - Suzanne Lemstra
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
| | - Chiara Toschi
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
| | - Rebecca L Barlow
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss 88397, Germany
| | - Anton Pekcec
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss 88397, Germany
| | - Tom Bretschneider
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss 88397, Germany
| | - Janet R Nicholson
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss 88397, Germany
| | - Trevor W Robbins
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
| | - Jeffrey W Dalley
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK,Department of Psychiatry, Addenbrooke’s Hospital, University of Cambridge, Cambridge CB2 2QQ, UK,Address correspondence to Professor Jeffrey W. Dalley, Department of Psychology, University of Cambridge, Downing St, Cambridge CB2 3EB, UK.
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Yuan C, Yang P, Wang J, Jiang L. Myo-inositol utilization by Citrobacter koseri promotes brain infection. Biochem Biophys Res Commun 2019; 517:427-432. [PMID: 31376937 DOI: 10.1016/j.bbrc.2019.07.112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 07/28/2019] [Indexed: 10/26/2022]
Abstract
Citrobacter species are opportunistic bacterial pathogens that are implicated in both nosocomial and community-acquired infections. Among the Citrobacter species, Citrobacter koseri is often isolated from clinical material, and it can cause meningitis and brain abscesses in neonates and immunocompromised individuals, thus posing a great threat to human health. However, the virulence determinants of C. koseri remain largely unknown. Myo-inositol is an abundant carbohydrate in the environment and in certain organs of the human body, especially the brain. The C. koseri genome harbors a cluster of genes, QCQ70420.1 to QCQ70429.1 (named the Ino-cluster in this study), which encode IolBCDE, MmsA, and an ATP-binding cassette transporter. The gene cluster may be involved in the utilization of myo-inositol. To investigate the functions of the Ino-cluster in C. koseri, we constructed a mutant strain by deleting the Ino-cluster and found that the mutant could not use myo-inositol as the sole carbon source, confirming that this cluster is responsible for myo-inositol utilization. Moreover, we investigated the function of the Ino-cluster and myo-inositol utilization in C. koseri pathogenicity. Deletion of the Ino-cluster significantly impaired C. koseri colonization of the brain of infected Sprague-Dawley (SD) rats and BALB/c mice, and this increased the survival rate of the infected animals, indicating that the Ino-cluster and the ability to use myo-inositol are essential for C. koseri pathogenicity. Taken together, our findings suggest that using the Ino-cluster products, C. koseri can exploit the abundant myo-inositol in the brain as a carbon source for growth, thus promoting colonization and virulence.
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Affiliation(s)
- Chao Yuan
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, PR China; TEDA Institue of Biological Sciences and Biotechnology, Nankai University, Tianjin, PR China; Tianjin Research Center for Functional Genomics and Biochips, TEDA College, Nankai University, Tianjin, PR China; Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin, PR China; College of Life Sciences, Nankai University, Tianjin, PR China
| | - Pan Yang
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, PR China; TEDA Institue of Biological Sciences and Biotechnology, Nankai University, Tianjin, PR China; Tianjin Research Center for Functional Genomics and Biochips, TEDA College, Nankai University, Tianjin, PR China; Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin, PR China; College of Life Sciences, Nankai University, Tianjin, PR China
| | - Junyue Wang
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, PR China; TEDA Institue of Biological Sciences and Biotechnology, Nankai University, Tianjin, PR China; Tianjin Research Center for Functional Genomics and Biochips, TEDA College, Nankai University, Tianjin, PR China; Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin, PR China; College of Life Sciences, Nankai University, Tianjin, PR China
| | - Lingyan Jiang
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, PR China; TEDA Institue of Biological Sciences and Biotechnology, Nankai University, Tianjin, PR China; Tianjin Research Center for Functional Genomics and Biochips, TEDA College, Nankai University, Tianjin, PR China; Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin, PR China.
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8
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Maeba R, Araki A, Fujiwara Y. Serum Ethanolamine Plasmalogen and Urine Myo-Inositol as Cognitive Decline Markers. Adv Clin Chem 2018; 87:69-111. [PMID: 30342713 DOI: 10.1016/bs.acc.2018.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Recent studies have suggested that metabolic disorders, particularly type 2 diabetes mellitus (T2DM), and dementia, including Alzheimer's disease (AD), were linked at the clinical and molecular levels. Brain insulin deficiency and resistance may be key events in AD pathology mechanistically linking AD to T2DM. Ethanolamine plasmalogens (PlsEtns) are abundant in the brain and play essential roles in neuronal function and myelin formation. As such, PlsEtn deficiency may be pathologically relevant in some neurodegenerative disorders such as AD. Decreased brain PlsEtn associated with dementia may reflect serum PlsEtn deficiency. We hypothesized that myo-inositol plays a role in myelin formation through its facilitation of PlsEtn biosynthesis. Excessive urinary myo-inositol (UMI) loss would likely result in PlsEtn deficiency potentially leading to demyelinating diseases such as dementia. Accordingly, measurement of both serum PlsEtn and baseline UMI excretion could improve the detection of cognitive impairment (CI) in a more specific and reliable manner. To verify our hypothesis, we conducted a clinical observational study of memory clinic outpatients (MCO) and cognitively normal elderly (NE) for nearly 4.5years. We demonstrated that serum PlsEtn concentration associated with UMI excretion was useful for predicting advancing dementia in patients with mild CI. Because hyperglycemia and associated insulin resistance might be a leading cause of increased baseline UMI excretion, serum PlsEtn quantitation would be useful in detecting CI among the elderly with hyperglycemia. Our findings suggest that myo-inositol is a novel candidate molecule linking T2DM to AD.
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Affiliation(s)
- Ryouta Maeba
- Department of Biochemistry, Teikyo University School of Medicine, Tokyo, Japan
| | - Atsushi Araki
- Department of Diabetes, Metabolism and Endocrinology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan
| | - Yoshinori Fujiwara
- Research Team for Social Participation and Community Health, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
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Chiu PW, Lui SSY, Hung KSY, Chan RCK, Chan Q, Sham PC, Cheung EFC, Mak HKF. In vivo gamma-aminobutyric acid and glutamate levels in people with first-episode schizophrenia: A proton magnetic resonance spectroscopy study. Schizophr Res 2018; 193:295-303. [PMID: 28751130 DOI: 10.1016/j.schres.2017.07.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 07/07/2017] [Accepted: 07/07/2017] [Indexed: 12/23/2022]
Abstract
BACKGROUND Gamma-aminobutyric acid (GABA) dysfunction and its consequent imbalance are implicated in the pathophysiology of schizophrenia. Reduced GABA production would lead to a disinhibition of glutamatergic neurons and subsequently cause a disruption of the modulation between GABAergic interneurons and glutamatergic neurons. In this study, levels of GABA, Glx (summation of glutamate and glutamine), and other metabolites in the anterior cingulate cortex were measured and compared between first-episode schizophrenia subjects and healthy controls (HC). Diagnostic potential of GABA and Glx as upstream biomarkers for schizophrenia was explored. METHODS Nineteen first-episode schizophrenia subjects and fourteen HC participated in this study. Severity of clinical symptoms of patients was measured with Positive and Negative Syndrome Scale (PANSS). Metabolites were measured using proton magnetic resonance spectroscopy, and quantified using internal water as reference. RESULTS First-episode schizophrenia subjects revealed reduced GABA and myo-inositol (mI), and increased Glx and choline (Cho), compared to HC. No significant correlation was found between metabolite levels and PANSS scores. Receiver operator characteristics analyses showed Glx had higher sensitivity and specificity (84.2%, 92.9%) compared to GABA (73.7%, 64.3%) for differentiating schizophrenia patients from HC. Combined model of both GABA and Glx revealed the best sensitivity and specificity (89.5%, 100%). CONCLUSION This study simultaneously showed reduction in GABA and elevation in Glx in first-episode schizophrenia subjects, and this might provide insights on explaining the disruption of modulation between GABAergic interneurons and glutamatergic neurons. Elevated Cho might indicate increased membrane turnover; whereas reduced mI might reflect dysfunction of the signal transduction pathway. In vivo Glx and GABA revealed their diagnostic potential for schizophrenia.
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Affiliation(s)
- P W Chiu
- Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, China; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Simon S Y Lui
- Castle Peak Hospital, Hong Kong, China; Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | | | - Raymond C K Chan
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, China; Department of Psychiatry, The University of Hong Kong, Hong Kong, China
| | | | - P C Sham
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China; Department of Psychiatry, The University of Hong Kong, Hong Kong, China
| | | | - Henry K F Mak
- Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, China; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China; Alzheimer's Disease Research Network, The University of Hong Kong, Hong Kong, China.
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10
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Das TK, Dey A, Sabesan P, Javadzadeh A, Théberge J, Radua J, Palaniyappan L. Putative Astroglial Dysfunction in Schizophrenia: A Meta-Analysis of 1H-MRS Studies of Medial Prefrontal Myo-Inositol. Front Psychiatry 2018; 9:438. [PMID: 30298023 PMCID: PMC6160540 DOI: 10.3389/fpsyt.2018.00438] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 08/24/2018] [Indexed: 11/22/2022] Open
Abstract
Background: Several lines of evidence support a role for astroglial pathology in schizophrenia. Myo-inositol is particularly abundant in astroglia. Many small sized studies have reported on myo-inositol concentration in schizophrenia, but to date these have not been pooled to estimate a collective effect size. Methods: We reviewed all proton magnetic resonance spectroscopy (1H-MRS) studies reporting myo-inositol values for patients satisfying DSM or ICD based criteria for schizophrenia in comparison to a healthy controls group in the medial prefrontal cortex published until February 2018. A random-effects model was used to calculate the pooled effect size using metafor package. A meta-regression analysis of moderator variables was also undertaken. Results: The literature search identified 19 studies published with a total sample size of 585 controls, 561 patients with schizophrenia. Patients with schizophrenia had significantly reduced medial prefrontal myo-inositol compared to controls (RFX standardized mean difference = 0.19, 95% CI [0.05-0.32], z = 2.72, p = 0.0067; heterogeneity p = 0.09). Studies with more female patients reported more notable schizophrenia-related reduction in myo-inositol (z = 2.53, p = 0.011). Discussion: We report a small, but significant reduction in myo-inositol concentration in the medial prefrontal cortex in schizophrenia. The size of the reported effect indicates that the biological pathways affecting the astroglia are likely to operate only in a subset of patients with schizophrenia. MRS myo-inositol could be a useful tool to stratify and investigate such patients.
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Affiliation(s)
- Tushar Kanti Das
- Department of Psychiatry, University of Western Ontario, London, ON, Canada.,Robarts Research Institute, London, ON, Canada.,Lawson Health Research Institute, London, ON, Canada
| | - Avyarthana Dey
- Department of Psychiatry, University of Western Ontario, London, ON, Canada.,Robarts Research Institute, London, ON, Canada
| | | | - Alborz Javadzadeh
- Department of Psychiatry, University of Western Ontario, London, ON, Canada
| | - Jean Théberge
- Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, University of Western Ontario, London, ON, Canada
| | - Joaquim Radua
- FIDMAG Germanes Hospitalàries, CIBERSAM, Sant Boi de Llobregat & Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Lena Palaniyappan
- Department of Psychiatry, University of Western Ontario, London, ON, Canada.,Robarts Research Institute, London, ON, Canada.,Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, University of Western Ontario, London, ON, Canada
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11
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Tipping the scales: Lessons from simple model systems on inositol imbalance in neurological disorders. Eur J Cell Biol 2017; 96:154-163. [PMID: 28153412 DOI: 10.1016/j.ejcb.2017.01.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/18/2017] [Accepted: 01/21/2017] [Indexed: 11/20/2022] Open
Abstract
Inositol and inositol-containing compounds have signalling and regulatory roles in many cellular processes, suggesting that inositol imbalance may lead to wide-ranging changes in cellular functions. Indeed, changes in inositol-dependent signalling have been implicated in various diseases and cellular functions such as autophagy, and these changes have often been proposed as therapeutic targets. However, few studies have highlighted the links between inositol depletion and the downstream effects on inositol phosphates and phosphoinositides in disease states. For this research, many advances have employed simple model systems that include the social amoeba D. discoideum and the yeast S. cerevisiae, since these models enable a range of experimental approaches that are not possible in mammalian models. In this review, we discuss recent findings initiated in simple model systems and translated to higher model organisms where the effect of altered inositol, inositol phosphate and phosphoinositide levels impact on bipolar disorder, Alzheimer disease, epilepsy and autophagy.
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Li J, Huang S, Dai HR, Wang J, Lin LH, Xiao H, Peng X, Li F, Wang YP, Yuan JM, Li L. A promoter polymorphism rs2075824 within IMPA2 gene affecting the transcription activity: possible relationship with schizophrenia. J Cell Mol Med 2016; 21:658-664. [PMID: 27748550 PMCID: PMC5345638 DOI: 10.1111/jcmm.13009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 09/11/2016] [Indexed: 01/24/2023] Open
Abstract
Previous studies with biological and genetic evidence indicate that the myo‐inositol monophosphatase 2 (IMPA2) gene may influence schizophrenia. We performed a genetic association study in Han Chinese cohorts. Five single nucleotide polymorphisms within IMPA2 promoter region (rs971363, rs971362, rs2075824, rs111410794 and rs111610121), as well as one (rs45442994, in intron 1) that was positively associated in another study, were selected for genotyping in 1397 patients with schizophrenia and 1285 mentally healthy controls. Genotype and allele frequencies were assessed by gender stratification. Interestingly, rs2075824 showed a strong association with schizophrenia (P = 4.1 × 10−4), and the T allele was more frequent in cases than controls [P = 5.6 × 10−5, OR (95% CI) = 1.26 (1.13–1.41)]. In vitro promoter assay showed that the transcription activity of the T allele promoter was higher than that of the C allele promoter and the T allele of rs2075824 contributed to risk for schizophrenia. By stratifying males and females, we found a gender‐specific association for IMPA2 and schizophrenia: the T allele of rs2075824 was more frequent in male cases compared with male controls [P = 1.4 × 10−4, OR (95% CI) = 1.33 (1.15–1.55)]. Our data suggest that a promoter polymorphism of IMPA2 possibly contributed to risk for schizophrenia by elevating transcription activity in Han Chinese individuals.
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Affiliation(s)
- Jia Li
- Department of Laboratory Medicine, School of Medicine, Shanghai General Hospital, Shanghai JiaoTong University, Shanghai, China
| | - Sheng Huang
- Department of Laboratory Medicine, School of Medicine, Shanghai General Hospital, Shanghai JiaoTong University, Shanghai, China
| | - Hui-Rong Dai
- Department of Laboratory Medicine, School of Medicine, Shanghai General Hospital, Shanghai JiaoTong University, Shanghai, China
| | - Juan Wang
- Department of Laboratory Medicine, School of Medicine, Shanghai General Hospital, Shanghai JiaoTong University, Shanghai, China
| | - Li-Hui Lin
- Department of Laboratory Medicine, School of Medicine, Shanghai General Hospital, Shanghai JiaoTong University, Shanghai, China
| | - Hui Xiao
- Department of Laboratory Medicine, School of Medicine, Shanghai General Hospital, Shanghai JiaoTong University, Shanghai, China
| | - Xia Peng
- Department of Laboratory Medicine, School of Medicine, Shanghai General Hospital, Shanghai JiaoTong University, Shanghai, China
| | - Fei Li
- Department of Laboratory Medicine, School of Medicine, Shanghai General Hospital, Shanghai JiaoTong University, Shanghai, China
| | - Yu-Ping Wang
- Department of Laboratory Medicine, School of Medicine, Shanghai General Hospital, Shanghai JiaoTong University, Shanghai, China
| | - Jian-Min Yuan
- Department of Central Laboratory, Wuxi Mental Health Center, Wuxi, Jiangsu, China
| | - Li Li
- Department of Laboratory Medicine, School of Medicine, Shanghai General Hospital, Shanghai JiaoTong University, Shanghai, China
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Frej AD, Clark J, Le Roy CI, Lilla S, Thomason PA, Otto GP, Churchill G, Insall RH, Claus SP, Hawkins P, Stephens L, Williams RSB. The Inositol-3-Phosphate Synthase Biosynthetic Enzyme Has Distinct Catalytic and Metabolic Roles. Mol Cell Biol 2016; 36:1464-79. [PMID: 26951199 PMCID: PMC4859692 DOI: 10.1128/mcb.00039-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 02/19/2016] [Accepted: 03/03/2016] [Indexed: 12/24/2022] Open
Abstract
Inositol levels, maintained by the biosynthetic enzyme inositol-3-phosphate synthase (Ino1), are altered in a range of disorders, including bipolar disorder and Alzheimer's disease. To date, most inositol studies have focused on the molecular and cellular effects of inositol depletion without considering Ino1 levels. Here we employ a simple eukaryote, Dictyostelium discoideum, to demonstrate distinct effects of loss of Ino1 and inositol depletion. We show that loss of Ino1 results in an inositol auxotrophy that can be rescued only partially by exogenous inositol. Removal of inositol supplementation from the ino1(-) mutant resulted in a rapid 56% reduction in inositol levels, triggering the induction of autophagy, reduced cytokinesis, and substrate adhesion. Inositol depletion also caused a dramatic generalized decrease in phosphoinositide levels that was rescued by inositol supplementation. However, loss of Ino1 triggered broad metabolic changes consistent with the induction of a catabolic state that was not rescued by inositol supplementation. These data suggest a metabolic role for Ino1 that is independent of inositol biosynthesis. To characterize this role, an Ino1 binding partner containing SEL1L1 domains (Q54IX5) and having homology to mammalian macromolecular complex adaptor proteins was identified. Our findings therefore identify a new role for Ino1, independent of inositol biosynthesis, with broad effects on cell metabolism.
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Affiliation(s)
- Anna D Frej
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, United Kingdom
| | - Jonathan Clark
- The Babraham Institute, Cambridge, Cambridgeshire, United Kingdom
| | - Caroline I Le Roy
- Department of Food and Nutritional Sciences, The University of Reading, Reading, Berkshire, United Kingdom
| | - Sergio Lilla
- Cancer Research UK Beatson Institute, Bearsden, Glasgow, United Kingdom
| | - Peter A Thomason
- Cancer Research UK Beatson Institute, Bearsden, Glasgow, United Kingdom
| | - Grant P Otto
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, United Kingdom
| | - Grant Churchill
- Department of Pharmacology, University of Oxford, Oxford, Oxfordshire, United Kingdom
| | - Robert H Insall
- Cancer Research UK Beatson Institute, Bearsden, Glasgow, United Kingdom
| | - Sandrine P Claus
- Department of Food and Nutritional Sciences, The University of Reading, Reading, Berkshire, United Kingdom
| | - Phillip Hawkins
- The Babraham Institute, Cambridge, Cambridgeshire, United Kingdom
| | - Len Stephens
- The Babraham Institute, Cambridge, Cambridgeshire, United Kingdom
| | - Robin S B Williams
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, United Kingdom
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Evaluation of Myo-Inositol as a Potential Biomarker for Depression in Schizophrenia. Neuropsychopharmacology 2015; 40:2157-64. [PMID: 25722115 PMCID: PMC4613604 DOI: 10.1038/npp.2015.57] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 02/11/2015] [Accepted: 02/16/2015] [Indexed: 12/31/2022]
Abstract
Depression is highly prevalent in patients with schizophrenia and is associated with significant clinical consequences, but there is no known biomarker for depression in schizophrenia. One of the putative neurochemical biomarkers for depression in major depressive disorder (MDD) is reduced cerebral concentration of myo-Inositol. We examined whether myo-Inositol levels provide a potential marker for depressive symptoms in schizophrenia similar to that in MDD and are informative regarding causal biological pathways underlying both depression and schizophrenia. We used proton magnetic resonance spectroscopy to examine myo-Inositol levels in the anterior cingulate cortex (ACC) in 59 schizophrenia spectrum disorder (SSD) patients and 69 matched community comparison participants. Participants completed the Maryland Trait and State Depression (MTSD) scale to measure symptoms of depression experienced around time of assessment ('State' subscale) and longitudinally ('Trait' subscale). Myo-Inositol in the ACC was negatively correlated with MTSD-Trait scores in both patients (ρ=-0.336, p=0.009) and community comparison samples (ρ=-0.328, p=0.006). Furthermore, patients with a diagnosis of schizoaffective disorder or a history of at least one major depressive episode had lower levels of myo-Inositol compared with schizophrenia patients without a current or past affective diagnosis (p=0.012). Since reduced brain myo-Inositol is associated with MDD, myo-Inositol may be a biochemical marker of depressive mood symptoms across diagnostic boundaries. If confirmed, this finding may aid investigation of the pathophysiology and therapeutics of depression common between depression, schizophrenia and other psychiatric diagnoses.
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Yan G, Xuan Y, Dai Z, Shen Z, Zhang G, Xu H, Wu R. Brain metabolite changes in subcortical regions after exposure to cuprizone for 6 weeks: potential implications for schizophrenia. Neurochem Res 2015; 40:49-58. [PMID: 25347963 DOI: 10.1007/s11064-014-1464-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 09/29/2014] [Accepted: 10/23/2014] [Indexed: 02/05/2023]
Abstract
Cuprizone is a copper chelating agent able to selectively damage the white matter in the mouse brain. Recent studies have reported behavioral abnormalities relevant to some of schizophrenia symptoms. While associating white matter damage to the behavioral abnormalities, these previous studies did not rule out the possible impairment in neuronal functions in cuprizone-exposed mice. The aim of this study was to examine brain metabolites of the cuprizone-exposed mice by proton magnetic resonance spectroscopy ((1)H-MRS). The examined brain regions were the caudoputamen, midbrain, and thalamus; these subcortical regions showed different susceptibilities to cuprizone in terms of demyelination and oligodendrocyte loss in previous studies. Young C57BL/6 mice were fed a standard rodent chow without or with cuprizone (0.2 %) for 6 weeks. At the end, open-field and Y-maze tests were performed to measure the emotional and cognitive behaviors of the animals, followed by (1)H-MRS procedure to evaluate the brain metabolites. Cuprizone-exposure increased anxiety levels and impaired spatial working memory. The same treatment increased T2 signal intensity in the cerebral cortex, hippocampus, and caudoputamen, but not in the thalamus. Cuprizone-exposure decreased the concentrations of NAA and NAA+NAAG in caudoputamen, but not in thalamus and midbrain. It decreased levels of Cr+PCr, GPC+PCh and myo-inositol in all the three brain regions. These results provided neurochemical evidence for the impairment in neuronal functions by cuprizone treatment.
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Affiliation(s)
- Gen Yan
- Department of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou, 515041, Guangdong, China
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16
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Matsumoto J, Sugiura Y, Yuki D, Hayasaka T, Goto-Inoue N, Zaima N, Kunii Y, Wada A, Yang Q, Nishiura K, Akatsu H, Hori A, Hashizume Y, Yamamoto T, Ikemoto K, Setou M, Niwa SI. Abnormal phospholipids distribution in the prefrontal cortex from a patient with schizophrenia revealed by matrix-assisted laser desorption/ionization imaging mass spectrometry. Anal Bioanal Chem 2011; 400:1933-43. [PMID: 21461619 PMCID: PMC3098351 DOI: 10.1007/s00216-011-4909-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 03/08/2011] [Accepted: 03/12/2011] [Indexed: 12/29/2022]
Abstract
Schizophrenia is one of the major psychiatric disorders, and lipids have focused on the important roles in this disorder. In fact, lipids related to various functions in the brain. Previous studies have indicated that phospholipids, particularly ones containing polyunsaturated fatty acyl residues, are deficient in postmortem brains from patients with schizophrenia. However, due to the difficulties in handling human postmortem brains, particularly the large size and complex structures of the human brain, there is little agreement regarding the qualitative and quantitative abnormalities of phospholipids in brains from patients with schizophrenia, particularly if corresponding brain regions are not used. In this study, to overcome these problems, we employed matrix-assisted laser desorption/ionization imaging mass spectrometry (IMS), enabling direct microregion analysis of phospholipids in the postmortem brain of a patient with schizophrenia via brain sections prepared on glass slides. With integration of traditional histochemical examination, we could analyze regions of interest in the brain at the micrometric level. We found abnormal phospholipid distributions within internal brain structures, namely, the frontal cortex and occipital cortex. IMS revealed abnormal distributions of phosphatidylcholine molecular species particularly in the cortical layer of frontal cortex region. In addition, the combined use of liquid chromatography/electrospray ionization tandem mass spectrometry strengthened the capability for identification of numerous lipid molecular species. Our results are expected to further elucidate various metabolic processes in the neural system.
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Affiliation(s)
- Junya Matsumoto
- Department of Neuropsychiatry, School of Medicine, Fukushima Medical University, 1 Hikarigaoka, Fukushima, Fukushima, 960-1295, Japan
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17
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Al-Khairi I, Baharnoori M, Kamath A, Bhardwaj SK, Srivastava LK. Altered expression and alpha-1 adrenergic receptor mediated activity of protein kinase C in the prefrontal cortex of rats with neonatal ventral hippocampus lesions. Synapse 2009; 63:1051-9. [DOI: 10.1002/syn.20691] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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18
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Tayoshi S, Sumitani S, Taniguchi K, Shibuya-Tayoshi S, Numata S, Iga JI, Nakataki M, Ueno SI, Harada M, Ohmori T. Metabolite changes and gender differences in schizophrenia using 3-Tesla proton magnetic resonance spectroscopy (1H-MRS). Schizophr Res 2009; 108:69-77. [PMID: 19097753 DOI: 10.1016/j.schres.2008.11.014] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2008] [Revised: 11/10/2008] [Accepted: 11/10/2008] [Indexed: 10/21/2022]
Abstract
A change in the glutamatergic system is thought to play an important role in the pathophysiology of schizophrenia. The aim of this study was to investigate the changes in metabolites, including glutamate (Glu), in the anterior cingulate cortex (ACC) and the left basal ganglia (ltBG) of patients with chronic schizophrenia using proton magnetic resonance spectroscopy ((1)H-MRS). In addition, since gender differences in this illness were known, we examined the effects of gender on these metabolites. The (1)H-MRS was performed on the ACC and ltBG of 30 patients with schizophrenia and 25 healthy individuals who acted as the control group. The levels of Glu, glutamine (Gln), creatine plus phosphocreatine (Cre), myo-inositol (mI), N-acetylaspartate (NAA), and choline-containing compounds (Cho) were measured. Two-way analysis of variance revealed that the illness significantly affected the levels of Glu and mI in the ACC; both metabolites were lower in the patients with schizophrenia as compared to the control subjects. The results also revealed that gender significantly affected the level of Gln in the ACC and the levels of Cre and NAA in the ltBG; the level of Gln in the ACC were higher in male subjects versus female subjects, whereas Cre and NAA levels in the ltBG were lower in male subjects as compared to female subjects. These results confirmed a change in the glutamatergic system and suggested an involvement of mI in the pathophysiology of schizophrenia.
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Affiliation(s)
- Shin'Ya Tayoshi
- Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, University of Tokushima Graduate School, Japan.
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McNamara RK, Ostrander M, Abplanalp W, Richtand NM, Benoit SC, Clegg DJ. Modulation of phosphoinositide-protein kinase C signal transduction by omega-3 fatty acids: implications for the pathophysiology and treatment of recurrent neuropsychiatric illness. Prostaglandins Leukot Essent Fatty Acids 2006; 75:237-57. [PMID: 16935483 DOI: 10.1016/j.plefa.2006.07.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The phosphoinositide (PI)-protein kinase C (PKC) signal transduction pathway is initiated by pre- and postsynaptic Galphaq-coupled receptors, and regulates several clinically relevant neurochemical events, including neurotransmitter release efficacy, monoamine receptor function and trafficking, monoamine transporter function and trafficking, axonal myelination, and gene expression. Mounting evidence for PI-PKC signaling hyperactivity in the peripheral (platelets) and central (premortem and postmortem brain) tissues of patients with schizophrenia, bipolar disorder, and major depressive disorder, coupled with evidence that PI-PKC signal transduction is down-regulated in rat brain following chronic, but not acute, treatment with antipsychotic, mood-stabilizer, and antidepressant medications, suggest that PI-PKC hyperactivity is central to an underlying pathophysiology. Evidence that membrane omega-3 fatty acids act as endogenous antagonists of the PI-PKC signal transduction pathway, coupled with evidence that omega-3 fatty acid deficiency is observed in peripheral and central tissues of patients with schizophrenia, bipolar disorder, and major depressive disorder, support the hypothesis that omega-3 fatty acid deficiency may contribute to elevated PI-PKC activity in these illnesses. The data reviewed in this paper outline a potential molecular mechanism by which omega-3 fatty acids could contribute to the pathophysiology and treatment of recurrent neuropsychiatric illness.
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Affiliation(s)
- Robert K McNamara
- Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0559, USA.
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Kim H, McGrath BM, Silverstone PH. A review of the possible relevance of inositol and the phosphatidylinositol second messenger system (PI-cycle) to psychiatric disorders--focus on magnetic resonance spectroscopy (MRS) studies. Hum Psychopharmacol 2005; 20:309-26. [PMID: 15880397 DOI: 10.1002/hup.693] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Myo-inositol is an important part of the phosphatidylinositol second messenger system (PI-cycle). Abnormalities in nerve cell myo-inositol levels and/or PI-cycle regulation has been suggested as being involved in the pathophysiology and/or treatment of many psychiatric disorders including bipolar disorder, major depressive disorder, panic disorder, obsessive-compulsive disorder, eating disorders and schizophrenia. This review examines the metabolism and biochemical importance of myo-inositol and the PI-cycle. It relates this to the current in vivo evidence for myo-inositol and PI-cycle involvement in these psychiatric disorders, particularly focusing upon the magnetic resonance spectroscopy (MRS) findings in patient studies to date. From this review it is concluded that while the evidence suggests probable relevance to the pathophysiology and/or treatment of bipolar disorder, there is much less support for a significant role for the PI-cycle or myo-inositol in any other psychiatric disorder. More definitive investigation is required before PI-cycle dysfunction can be considered specific to bipolar disorder.
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Affiliation(s)
- Hyeonjin Kim
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
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Osuch E, Ursano R, Li H, Webster M, Hough C, Fullerton C, Leskin G. Brain environment interactions: stress, posttraumatic stress disorder, and the need for a postmortem brain collection. Psychiatry 2004; 67:353-83. [PMID: 15801377 DOI: 10.1521/psyc.67.4.353.56565] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Stress, especially the extreme stress of traumatic events, can alter both neurobiology and behavior. Such extreme environmental situations provide a useful model for understanding environmental influences on human biology and behavior. This paper will review some of the evidence of brain alterations that occur with exposure to environmental stress. This will include recent studies using neuroimaging and will address the need for histological confirmation of imaging study results. We will review the current scientific approaches to understanding brain environment interactions, and then make the case for the collection and study of postmortem brain tissue for the advancement of our understanding of the effects of environment on the brain. Creating a brain tissue collection specifically for the investigation of the effects of extreme environmental stressors fills a gap in the current research; it will provide another of the important pieces to the puzzle that constitutes the scientific investigation of negative effects of environmental exposures. Such a resource will facilitate new discoveries related to the psychiatric illnesses of acute stress disorder and posttraumatic stress disorder, and can enable scientists to correlate structural and functional imaging findings with tissue abnormalities, which is essential to validate the results of recent imaging studies.
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MESH Headings
- Acoustic Stimulation/adverse effects
- Axons/physiology
- Brain/metabolism
- Brain/pathology
- Brain/physiopathology
- Environment
- Epinephrine/blood
- Epinephrine/urine
- Humans
- Limbic System/anatomy & histology
- Limbic System/metabolism
- Limbic System/pathology
- Limbic System/physiopathology
- Norepinephrine/blood
- Norepinephrine/urine
- Reflex, Startle
- Stress Disorders, Post-Traumatic/metabolism
- Stress Disorders, Post-Traumatic/physiopathology
- Stress Disorders, Post-Traumatic/psychology
- Stress Disorders, Traumatic, Acute/metabolism
- Stress Disorders, Traumatic, Acute/physiopathology
- Stress Disorders, Traumatic, Acute/psychology
- Tissue Banks
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Affiliation(s)
- Elizabeth Osuch
- Department of Psychiatry, Uniformed Services Universityof the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
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Stopkova P, Saito T, Fann CSJ, Papolos DF, Vevera J, Paclt I, Zukov I, Stryjer R, Strous RD, Lachman HM. Polymorphism screening of PIP5K2A: a candidate gene for chromosome 10p-linked psychiatric disorders. Am J Med Genet B Neuropsychiatr Genet 2003; 123B:50-8. [PMID: 14582145 DOI: 10.1002/ajmg.b.20012] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Lithium is a potent noncompetitive inhibitor of inositol monophosphatases, enzymes involved in phosphoinositide (PI) and inositol phosphate metabolism. A critical component of the PI pathway is phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P(2)), which is hydrolyzed to second messengers and has a direct role in synaptic vesicle function. Interestingly, a number of genes involved in the synthesis and dephosphorylation of PtdIns(4,5)P(2) are found in regions of the genome previously mapped in bipolar disorder (BD) including 10p12, 21q22, and 22q11, among others. Some of these regions overlap with loci mapped in schizophrenia (SZ). One gene involved in PI metabolism that maps to a region of interest is 10p12-linked PIP5K2A, a member of the phosphatidylinositol 4-phosphate 5-kinase family. Polymorphism screening revealed the existence of an imperfect CT repeat polymorphism located near the exon 9-intron 9 splice donor site. A modest difference was found in the distribution of alleles from this highly polymorphic variant when bipolar and schizophrenic subjects were compared with controls; relatively rare short repeat variants were found more commonly in patients and homozygosity for a common long repeat variant was found more commonly in controls. These data suggest that the imperfect CT repeat in PIP5K2A intron 9 should be further investigated as a possible candidate allele for 10p12-linked psychiatric disorders.
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Affiliation(s)
- Pavla Stopkova
- Department of Psychiatry and Behavioral Sciences, Division of Psychiatry Research, Albert Einstein College of Medicine, New York 10461, USA
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Arranz B, Rosel P, Sarró S, Ramirez N, Dueñas R, Cano R, María Sanchez J, San L. Altered platelet serotonin 5-HT2A receptor density but not second messenger inositol trisphosphate levels in drug-free schizophrenic patients. Psychiatry Res 2003; 118:165-74. [PMID: 12798981 DOI: 10.1016/s0165-1781(03)00073-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The 5-HT2A receptor binding parameters using [3H]ketanserine and its intracellular signal inositol 1,4,5 trisphosphate (IP3) concentrations were determined in platelets from schizophrenic patients so as to assess differences with respect to a control group and to a standardized antipsychotic drug treatment. Seventy-five antipsychotic-free patients with a DSM-IV diagnosis of paranoid schizophrenia were included in the study. Blood samples were collected before the onset of antipsychotic treatment (baseline values) and after 3 weeks of treatment. Antipsychotic-free schizophrenic patients showed significantly increased basal 5-HT2A densities in comparison to the control group, together with a significantly increase (23%) in the 5-HT2A binding density in those patients treated with risperidone. These changes could be attributed to an up-regulation of 5-HT2A receptors caused by previous treatment with antipsychotic drugs, which is consistent with the chronic effect of 5-HT2A antagonists to up-regulate the number of binding sites. With regard to second messenger IP3 concentrations, basal concentrations in schizophrenic patients were not significantly different from control values, nor was there any significant difference between basal vs. posttreatment values. These results are possibly related to failure of second messenger systems of 'translating' extracellular messages generated presynaptically into effective neurotransmitter signals in schizophrenic patients.
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Affiliation(s)
- Belén Arranz
- Benito Menni, Mental Health Care Institute, Antoni Pujadas 38, 08830 Sant Boi de Llobregat, Barcelona, Spain
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Fisher SK, Novak JE, Agranoff BW. Inositol and higher inositol phosphates in neural tissues: homeostasis, metabolism and functional significance. J Neurochem 2002; 82:736-54. [PMID: 12358779 DOI: 10.1046/j.1471-4159.2002.01041.x] [Citation(s) in RCA: 465] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Inositol phospholipids and inositol phosphates mediate well-established functions in signal transduction and in Ca2+ homeostasis in the CNS and non-neural tissues. More recently, there has been renewed interest in other roles that both myo-inositol and its highly phosphorylated forms may play in neural function. We review evidence that myo-inositol serves as a clinically relevant osmolyte in the CNS, and that its hexakisphosphate and pyrophosphorylated derivatives may play roles in such diverse cellular functions as DNA repair, nuclear RNA export and synaptic membrane trafficking.
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Affiliation(s)
- Stephen K Fisher
- Mental Health Research Institute, and Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, USA.
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25
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Belmaker RH, Shapiro J, Vainer E, Nemanov L, Ebstein RP, Agam G. Reduced inositol content in lymphocyte-derived cell lines from bipolar patients. Bipolar Disord 2002; 4:67-9. [PMID: 12047497 DOI: 10.1034/j.1399-5618.2002.00108.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES The study aimed to determine whether low inositol content and uptake previously reported in brain and peripheral tissue of bipolar patients are also reflected in lymphocyte-derived cell lines from these patients. METHODS Inositol content and uptake were studied in lymphocyte-derived cell lines grown in vitro for at least five generations to eliminate influences of drug treatment. Inositol content was studied gas chromatographically and inositol uptake by following 3H-inositol incorporation at various concentrations. RESULTS Inositol levels of cell lines derived from bipolar patients were significantly lower than those of cell lines from controls. CONCLUSIONS Low inositol content in lymphocyte-derived cell lines from bipolar patients corroborates previous findings in frontal cortex and in lymphoblastoid cell lines and are consistent with the notion that the phosphatidylinositol signaling system is involved in the pathophysiology of this disorder.
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Affiliation(s)
- R H Belmaker
- Stanley Foundation Research Center, Ben-Gurion University of the Negev, Beersheva, Israel
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Affiliation(s)
| | - Scott E. Hemby
- Corresponding author: Yerkes Regional Primate Center 954 Gatewood Road, NE Atlanta, GA 30329 Telephone: (404) 727-5988 Fax: (404) 727-8756
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Auer DP, Wilke M, Grabner A, Heidenreich JO, Bronisch T, Wetter TC. Reduced NAA in the thalamus and altered membrane and glial metabolism in schizophrenic patients detected by 1H-MRS and tissue segmentation. Schizophr Res 2001; 52:87-99. [PMID: 11595395 DOI: 10.1016/s0920-9964(01)00155-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Functional and structural abnormalities in the thalamus as well as a generalized phospholipid membrane disorder have been implicated in the pathogenesis of schizophrenic psychosis. To determine whether thalamic neuronal abnormalities and altered membrane-associated metabolites can be detected in schizophrenic patients, we used in vivo proton magnetic resonance spectroscopy (1H-MRS) in 32 acutely-ill, medicated schizophrenic patients and 17 age-matched controls. Thalamic and white matter metabolite concentrations (myo-inositol (mI), choline-containing compounds (Cho), total creatine (Cr) and N-acetylaspartate (NAA)) were estimated and corrected for atrophy (CSF) and gray and white matter contributions (GM, WM) by use of image-based voxel segmentation. Thalamic NAA was significantly reduced in schizophrenic patients, whereas Cho and mI were significantly increased in the parietal white matter. White matter Cr was significantly elevated in patients and correlated positively with the brief psychiatric rating scores (BPRS). Regional metabolite levels were inversely associated with GM and WM content reaching significance for mI and Cr in the thalamus and Cho and NAA in the white matter. Reduced NAA in the left thalamus of schizophrenic patients confirms and extends previous spectroscopic data and agrees well with histologic and imaging findings of reduced neuronal density and volume. Elevated Cho in line with 31P-MRS studies suggests increased myelin degradation thus further supporting a generalized membrane disorder in schizophrenic patients. In addition, we demonstrate the need to correct metabolite concentrations for regional tissue composition in studies employing patients with altered brain morphology.
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Affiliation(s)
- D P Auer
- Max Planck Institute of Psychiatry, Kraepelinstrasse 10, 80804, München, Germany.
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Shaltiel G, Shamir A, Nemanov L, Yaroslavsky Y, Nemets B, Ebstein RP, Belmaker RH, Agam G. Inositol monophosphatase activity in brain and lymphocyte-derived cell lines of bipolar patients. World J Biol Psychiatry 2001; 2:95-8. [PMID: 12587191 DOI: 10.3109/15622970109027499] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Inositol monophosphatase (IMPase) activity was reported to be low in lymphocyte-derived cell lines of bipolar patients. METHODS IMPase activity was measured spectrophotometrically as inorganic phosphate liberated from inositol-1-phosphate. RESULTS The previously reported reduction was replicated in a new, small group of bipolar patients. The reduction is not present in cell lines of unipolar or schizophrenic patients. IMPase activity in postmortem frontal and occipital cortical samples of unipolar, bipolar and schizophrenic patients was not different from controls. CONCLUSIONS A reduction in lymphocyte-derived IMPase activity without a parallel reduction in cortical IMPase activity could be due to the fact that most leukocyte IMPase activity is the product of the IMPA-2 gene.
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Affiliation(s)
- G Shaltiel
- Stanley Research Center, Department of Clinical Biochemistry, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beersheva, Israel
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Yoshikawa T, Kikuchi M, Saito K, Watanabe A, Yamada K, Shibuya H, Nankai M, Kurumaji A, Hattori E, Ishiguro H, Shimizu H, Okubo Y, Toru M, Detera-Wadleigh SD. Evidence for association of the myo-inositol monophosphatase 2 (IMPA2) gene with schizophrenia in Japanese samples. Mol Psychiatry 2001; 6:202-10. [PMID: 11317223 DOI: 10.1038/sj.mp.4000835] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2000] [Revised: 09/17/2000] [Accepted: 09/20/2000] [Indexed: 11/09/2022]
Abstract
In our search for candidate genes for affective disorder on the short arm of chromosome 18, we cloned IMPA2, a previously unreported myo-inositol monophosphatase gene, that maps to 18p11.2. We determined its genomic structure and detected three new single nucleotide polymorphisms (SNPs). In the present study, we screened the gene further to search for additional polymorphisms in Japanese samples and identified seven other SNPs, including a novel missense mutation. These polymorphisms clustered into three regions of the gene. Three relatively informative SNPs, 58G>A, IVS1--15G>A and 800C>T from clusters 1, 2 and 3, respectively, were selected for association tests using a case-control design. The Japanese cohort included 302 schizophrenics, 205 patients with affective disorder and 308 controls. Genotyping was done either by melting curve analysis on the LightCycler or by sequencing. All three SNPs showed significant genotypic association (nominal P = 0.031--0.0001) with schizophrenia, but not with affective disorder. These findings increase the relevance of 18p11.2 to schizophrenia susceptibility because GNAL, which has been shown previously to be implicated in schizophrenia in an independent study, is in close physical proximity to IMPA2. Our findings suggest that IMPA2 or a gene nearby may contribute to the overall genetic risk for schizophrenia among Japanese.
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Affiliation(s)
- T Yoshikawa
- Laboratory for Molecular Psychiatry, Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan.
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Mirnics K, Middleton FA, Marquez A, Lewis DA, Levitt P. Molecular characterization of schizophrenia viewed by microarray analysis of gene expression in prefrontal cortex. Neuron 2000; 28:53-67. [PMID: 11086983 DOI: 10.1016/s0896-6273(00)00085-4] [Citation(s) in RCA: 728] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Microarray expression profiling of prefrontal cortex from matched pairs of schizophrenic and control subjects and hierarchical data analysis revealed that transcripts encoding proteins involved in the regulation of presynaptic function (PSYN) were decreased in all subjects with schizophrenia. Genes of the PSYN group showed a different combination of decreased expression across subjects. Over 250 other gene groups did not show altered expression. Selected PSYN microarray observations were verified by in situ hybridization. Two of the most consistently changed transcripts in the PSYN functional gene group, N-ethylmaleimide sensitive factor and synapsin II, were decreased in ten of ten and nine of ten subjects with schizophrenia, respectively. The combined data suggest that subjects with schizophrenia share a common abnormality in presynaptic function. We set forth a predictive, testable model.
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Affiliation(s)
- K Mirnics
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pennsylvania 15261, USA. karoly+@pitt.edu
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Chengappa KN, Levine J, Gershon S, Mallinger AG, Hardan A, Vagnucci A, Pollock B, Luther J, Buttenfield J, Verfaille S, Kupfer DJ. Inositol as an add-on treatment for bipolar depression. Bipolar Disord 2000; 2:47-55. [PMID: 11254020 DOI: 10.1034/j.1399-5618.2000.020107.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Inositol is a constituent of the intracellular phosphatidyl inositol (PI) second messenger system, which is linked to various neurotransmitter receptors. Inositol crosses the blood-brain barrier in pharmacological doses, and has shown efficacy in a small double-blind study of unipolar depression. This pilot study evaluated its potential efficacy and safety in bipolar depression. METHODS Twenty-four consenting adult men and women with DSM-IV bipolar depression (bipolar I = 21; bipolar II = 3) were randomly assigned to receive either 12 g of inositol or D-glucose as placebo for 6 weeks. Efficacy and safety ratings were done weekly. Thymoleptic medications (lithium, valproate, carbamazepine) in stable doses and at therapeutic levels at study entry were continued unchanged. RESULTS Two subjects receiving placebo dropped out early due to worsening or non-adherence to the protocol. Among the 22 subjects who completed the trial, six (50%) of the inositol-treated subjects responded with a 50% or greater decrease in the baseline Hamilton Depression Rating Scale (HAM-D) score and a Clinical Global Improvement (CGI) scale score change of 'much' or 'very much' improved, as compared to three (30%) subjects assigned to placebo, a statistically nonsignificant difference. On the Montgomery-Asberg Depression Rating Scale (MADRS), eight (67%) of twelve inositol-treated subjects had a 50% or greater decrease in the baseline MADRS scores compared to four (33%) of twelve subjects assigned to placebo (p = 0.10). Inositol was well tolerated with minimal side effects, and thymoleptic blood levels were unaltered. CONCLUSIONS These pilot data suggest a controlled study with an adequate sample size, and the appropriate rating scale may demonstrate efficacy for inositol in bipolar depression. The tolerability and the 'natural substance' aspect of inositol may be particularly appealing to subjects with bipolar depression.
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Affiliation(s)
- K N Chengappa
- Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, PA, USA.
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