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Klausing AD, Fukuwatari T, DeAngeli N, Bucci DJ, Schwarcz R. Adrenalectomy exacerbates stress-induced impairment in fear discrimination: A causal role for kynurenic acid? Biochem Pharmacol 2024; 228:116350. [PMID: 38852644 DOI: 10.1016/j.bcp.2024.116350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/28/2024] [Accepted: 06/06/2024] [Indexed: 06/11/2024]
Abstract
Impaired activity of the hypothalamic-pituitary axis and reduced blood levels of glucocorticoids (GCs) are signature features of stress-related maladies. Recent evidence suggests a possible role of the tryptophan metabolite kynurenic acid (KYNA) in this context. Here we investigated possible causal relationships in adult male rats, using stress-induced fear discrimination as a translationally relevant behavioral outcome measure. One week following adrenalectomy (ADX) or sham surgery, animals were for 2 h either physically restrained or exposed to a predator odor, which caused a much milder stress response. Extracellular KYNA levels were determined before, during and after stress by in vivo microdialysis in the prefrontal cortex. Separate cohorts underwent a fear discrimination procedure starting immediately after stress termination. Different auditory conditioned stimuli (CS) were either paired with a foot shock (CS+) or non-reinforced (CS-). One week later, fear was assessed by re-exposing the animals to each CS. Separate groups of rats were treated with the KYNA synthesis inhibitor BFF-816 prior to stress initiation to test a causal role of KYNA in fear discrimination. Restraint stress raised extracellular KYNA levels by ∼85 % in ADX rats for several hours, and these animals were unable to discriminate between CS+ and CS-. Both effects were prevented by BFF-816 and were not observed after exposure to predator odor or in sham-operated rats. These findings suggest that a causal connection exists between adrenal function, stress-induced KYNA increases, and behavioral deficits. Pharmacological inhibition of KYNA synthesis may therefore be an attractive, novel option for the treatment of stress-related disorders.
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Affiliation(s)
- Alex D Klausing
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Tsutomu Fukuwatari
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Nicole DeAngeli
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, USA
| | - David J Bucci
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, USA
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA.
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2
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Gary NC, Misganaw B, Hammamieh R, Gautam A. Exploring metabolomic dynamics in acute stress disorder: amino acids, lipids, and carbohydrates. Front Genet 2024; 15:1394630. [PMID: 39119583 PMCID: PMC11306072 DOI: 10.3389/fgene.2024.1394630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 07/04/2024] [Indexed: 08/10/2024] Open
Abstract
Acute Stress Disorder (ASD) is a psychiatric condition that can develop shortly after trauma exposure. Although molecular studies of ASD are only beginning, groups of metabolites have been found to be significantly altered with acute stress phenotypes in various pre-clinical and clinical studies. ASD implicated metabolites include amino acids (β-hydroxybutyrate, glutamate, 5-aminovalerate, kynurenine and aspartate), ketone bodies (β-hydroxybutyrate), lipids (cortisol, palmitoylethanomide, and N-palmitoyl taurine) and carbohydrates (glucose and mannose). Network and pathway analysis with the most prominent metabolites shows that Extracellular signal-regulated kinases and c-AMP response element binding (CREB) protein can be crucial players. After highlighting main recent findings on the role of metabolites in ASD, we will discuss potential future directions and challenges that need to be tackled. Overall, we aim to showcase that metabolomics present a promising opportunity to advance our understanding of ASD pathophysiology as well as the development of novel biomarkers and therapeutic targets.
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Affiliation(s)
- Nicholas C. Gary
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, United States
- The Geneva Foundation, Tacoma, WA, United States
| | - Burook Misganaw
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, United States
- Culmen International, Alexandria, VA, United States
| | - Rasha Hammamieh
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Aarti Gautam
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, United States
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3
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Pivac N, Vuic B, Sagud M, Nedic Erjavec G, Nikolac Perkovic M, Konjevod M, Tudor L, Svob Strac D, Uzun S, Kozumplik O, Uzun S, Mimica N. PTSD, Immune System, and Inflammation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1411:225-262. [PMID: 36949313 DOI: 10.1007/978-981-19-7376-5_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
Posttraumatic stress disorder (PTSD) is a severe trauma and stress-related disorder associated with different somatic comorbidities, especially cardiovascular and metabolic disorders, and with chronic low-grade inflammation. Altered balance of the hypothalamic-pituitary-adrenal (HPA) axis, cytokines and chemokines, C-reactive protein, oxidative stress markers, kynurenine pathways, and gut microbiota might be involved in the alterations of certain brain regions regulating fear conditioning and memory processes, that are all altered in PTSD. In addition to the HPA axis, the gut microbiota maintains the balance and interaction of the immune, CNS, and endocrine pathways forming the gut-brain axis. Disbalance in the HPA axis, gut-brain axis, oxidative stress pathways and kynurenine pathways, altered immune signaling and disrupted homeostasis, as well as the association of the PTSD with the inflammation and disrupted cognition support the search for novel strategies for treatment of PTSD. Besides potential anti-inflammatory treatment, dietary interventions or the use of beneficial bacteria, such as probiotics, can potentially improve the composition and the function of the bacterial community in the gut. Therefore, bacterial supplements and controlled dietary changes, with exercise, might have beneficial effects on the psychological and cognitive functions in patients with PTSD. These new treatments should be aimed to attenuate inflammatory processes and consequently to reduce PTSD symptoms but also to improve cognition and reduce cardio-metabolic disorders associated so frequently with PTSD.
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Affiliation(s)
- Nela Pivac
- Division of Molecular Medicine, Laboratory for Molecular Neuropsychiatry, Rudjer Boskovic Institute, Zagreb, Croatia.
| | - Barbara Vuic
- Division of Molecular Medicine, Laboratory for Molecular Neuropsychiatry, Rudjer Boskovic Institute, Zagreb, Croatia
| | - Marina Sagud
- Department of Psychiatry, University Hospital Center Zagreb, Zagreb, Croatia
- University of Zagreb School of Medicine, Zagreb, Croatia
| | - Gordana Nedic Erjavec
- Division of Molecular Medicine, Laboratory for Molecular Neuropsychiatry, Rudjer Boskovic Institute, Zagreb, Croatia
| | - Matea Nikolac Perkovic
- Division of Molecular Medicine, Laboratory for Molecular Neuropsychiatry, Rudjer Boskovic Institute, Zagreb, Croatia
| | - Marcela Konjevod
- Division of Molecular Medicine, Laboratory for Molecular Neuropsychiatry, Rudjer Boskovic Institute, Zagreb, Croatia
| | - Lucija Tudor
- Division of Molecular Medicine, Laboratory for Molecular Neuropsychiatry, Rudjer Boskovic Institute, Zagreb, Croatia
| | - Dubravka Svob Strac
- Division of Molecular Medicine, Laboratory for Molecular Neuropsychiatry, Rudjer Boskovic Institute, Zagreb, Croatia
| | - Suzana Uzun
- University of Zagreb School of Medicine, Zagreb, Croatia
- University Psychiatric Hospital Vrapce, Zagreb, Croatia
| | | | - Sandra Uzun
- Department for Anesthesiology, Reanimatology, and Intensive Care, University Hospital Center Zagreb, Zagreb, Croatia
| | - Ninoslav Mimica
- University of Zagreb School of Medicine, Zagreb, Croatia
- University Psychiatric Hospital Vrapce, Zagreb, Croatia
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4
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Moravcová S, Spišská V, Pačesová D, Hrubcová L, Kubištová A, Novotný J, Bendová Z. Circadian control of kynurenine pathway enzymes in the rat pineal gland, liver, and heart and tissue- and enzyme-specific responses to lipopolysaccharide. Arch Biochem Biophys 2022; 722:109213. [DOI: 10.1016/j.abb.2022.109213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 03/10/2022] [Accepted: 04/07/2022] [Indexed: 11/26/2022]
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5
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Ugwu PI, Ben-Azu B, Ugwu SU, Uruaka CI, Nworgu CC, Okorie PO, Okafor KO, Anachuna KK, Elendu MU, Ugwu AO, Anyaehie UB, Nwankwo AA, Osim EE. Putative mechanisms involved in the psychopathologies of mice passively coping with psychosocial defeat stress by quercetin. Brain Res Bull 2022; 183:127-141. [DOI: 10.1016/j.brainresbull.2022.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 02/15/2022] [Accepted: 03/07/2022] [Indexed: 12/14/2022]
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6
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Herhaus B, Joisten N, Wessels I, Zimmer P, Petrowski K. How acute physical and psychological stress differentially influence the kynurenine pathway: A randomized cross-over trial. Psychoneuroendocrinology 2021; 134:105433. [PMID: 34695711 DOI: 10.1016/j.psyneuen.2021.105433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/30/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022]
Abstract
Psychological stress is associated with the pathogenesis of several neuropsychiatric disorders. In contrast, physical stress, as provoked by exercise, counteracts symptoms and potentially also disease progression. The kynurenine pathway, which is imbalanced in neuropsychiatric disorders, responds to both psychological and physical stress. Here, we compared the acute effects of psychological versus physical stress on the kynurenine pathway and inflammatory mediators. Thirty-five healthy males (mean age: 24.09±3.39 years) underwent both the Trier Social Stress Test (psychological stressor) and the Wingate-Test (physical stressor). The kinetics of tryptophan and its metabolites as well as cytokines IL-6, IFN-γ, TNF-α, and IL-10 were measured before and after the two stress conditions. After both stressors, there was a significant change over time for the kinetics of tryptophan metabolites and for cytokines. Furthermore, the reactivity of kynurenine pathway metabolite ratios and cytokines was statistically greater after physical stress than after psychological stress. The increased metabolic flux towards kynurenic acid following acute physical stress suggests an exercise-induced neuroprotective mechanism. Despite the paradoxical influence of both stressors on neuropsychiatric diseases, the acute kynurenine pathway reactivity appears to be similar, although effects were more pronounced in response to physical stress.
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Affiliation(s)
- Benedict Herhaus
- Medical Psychology and Medical Sociology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Niklas Joisten
- Division of Performance and Health (Sports Medicine), Department for Sport and Sport Science, TU Dortmund University, Dortmund, Germany.
| | - Inga Wessels
- Institute of Immunology, Medical Faculty, RWTH Aachen University, Aachen, Nordrhein-Westfalen, Germany
| | - Philipp Zimmer
- Division of Performance and Health (Sports Medicine), Department for Sport and Sport Science, TU Dortmund University, Dortmund, Germany
| | - Katja Petrowski
- Medical Psychology and Medical Sociology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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7
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Strzelewicz AR, Vecchiarelli HA, Rondón-Ortiz AN, Raneri A, Hill MN, Kentner AC. Interactive effects of compounding multidimensional stressors on maternal and male and female rat offspring outcomes. Horm Behav 2021; 134:105013. [PMID: 34171577 PMCID: PMC8403628 DOI: 10.1016/j.yhbeh.2021.105013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 10/21/2022]
Abstract
Exposure to adverse childhood experiences (ACEs) is a risk factor for the development of psychiatric disorders in addition to cardiovascular associated diseases. This risk is elevated when the cumulative burden of ACEs is increased. Laboratory animals can be used to model the changes (as well as the underlying mechanisms) that result in response to adverse events. In this study, using male and female Sprague Dawley rats, we examined the impact of increasing stress burden, utilizing both two adverse early life experiences (parental/offspring high fat diet + limited bedding exposure) and three adverse early life experiences (parental/offspring high fat diet + limited bedding exposure + neonatal inflammation), on maternal care quality and offspring behavior. Additionally, we measured hormones and hippocampal gene expression related to stress. We found that the adverse perinatal environment led to a compensatory increase in maternal care. Moreover, these dams had reduced maternal expression of oxytocin receptor, compared to standard housed dams, in response to acute stress on postnatal day (P)22. In offspring, the two-hit and three-hit models resulted in a hyperlocomotor phenotype and increased body weights. Plasma leptin and hippocampal gene expression of corticotropin releasing hormone (Chrh)1 and Crhr2 were elevated (males) while expression of oxytocin was reduced (females) following acute stress. On some measures (e.g., hyperlocomotion, leptin), the magnitude of change was lower in the three-hit compared to the two-hit model. This suggests that multiple early adverse events can have interactive, and often unpredictable, impacts, highlighting the importance of modeling complex interactions amongst stressors during development.
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Affiliation(s)
- Arielle R Strzelewicz
- School of Pharmacy, Massachusetts College of Pharmacy and Health Sciences, Boston, MA 02115, United States
| | - Haley A Vecchiarelli
- Divisions of Medical Sciences, University of Victoria, BC V8P 5C2, Canada; Neuroscience Graduate Program, Hotchkiss Brain Institute, Mathison Centre for Mental Health, Research and Education, Cumming School of Medicine, University of Calgary, AB T2N 1N4, Canada
| | - Alejandro N Rondón-Ortiz
- School of Pharmacy, Massachusetts College of Pharmacy and Health Sciences, Boston, MA 02115, United States
| | - Anthony Raneri
- School of Arts & Sciences, Massachusetts College of Pharmacy and Health Sciences, Boston, MA 02115, United States
| | - Matthew N Hill
- Neuroscience Graduate Program, Hotchkiss Brain Institute, Mathison Centre for Mental Health, Research and Education, Cumming School of Medicine, University of Calgary, AB T2N 1N4, Canada
| | - Amanda C Kentner
- School of Arts & Sciences, Massachusetts College of Pharmacy and Health Sciences, Boston, MA 02115, United States.
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8
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Sanguino‐Gómez J, Buurstede JC, Abiega O, Fitzsimons CP, Lucassen PJ, Eggen BJL, Lesuis SL, Meijer OC, Krugers HJ. An emerging role for microglia in stress‐effects on memory. Eur J Neurosci 2021; 55:2491-2518. [PMID: 33724565 PMCID: PMC9373920 DOI: 10.1111/ejn.15188] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 02/13/2021] [Accepted: 03/03/2021] [Indexed: 12/14/2022]
Abstract
Stressful experiences evoke, among others, a rapid increase in brain (nor)epinephrine (NE) levels and a slower increase in glucocorticoid hormones (GCs) in the brain. Microglia are key regulators of neuronal function and contain receptors for NE and GCs. These brain cells may therefore potentially be involved in modulating stress effects on neuronal function and learning and memory. In this review, we discuss that stress induces (1) an increase in microglial numbers as well as (2) a shift toward a pro‐inflammatory profile. These microglia have (3) impaired crosstalk with neurons and (4) disrupted glutamate signaling. Moreover, microglial immune responses after stress (5) alter the kynurenine pathway through metabolites that impair glutamatergic transmission. All these effects could be involved in the impairments in memory and in synaptic plasticity caused by (prolonged) stress, implicating microglia as a potential novel target in stress‐related memory impairments.
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Affiliation(s)
| | - Jacobus C. Buurstede
- Department of Medicine Division of Endocrinology Leiden University Medical Center Leiden The Netherlands
| | - Oihane Abiega
- Brain Plasticity Group SILS‐CNS University of Amsterdam Amsterdam The Netherlands
| | - Carlos P. Fitzsimons
- Brain Plasticity Group SILS‐CNS University of Amsterdam Amsterdam The Netherlands
| | - Paul J. Lucassen
- Brain Plasticity Group SILS‐CNS University of Amsterdam Amsterdam The Netherlands
| | - Bart J. L. Eggen
- Department of Biomedical Sciences of Cells & Systems Section Molecular Neurobiology University of Groningen University Medical Center Groningen Groningen The Netherlands
| | - Sylvie L. Lesuis
- Brain Plasticity Group SILS‐CNS University of Amsterdam Amsterdam The Netherlands
- Program in Neurosciences and Mental Health Hospital for Sick Children Toronto ON Canada
| | - Onno C. Meijer
- Department of Medicine Division of Endocrinology Leiden University Medical Center Leiden The Netherlands
| | - Harm J. Krugers
- Brain Plasticity Group SILS‐CNS University of Amsterdam Amsterdam The Netherlands
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9
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Vecchiarelli HA, Morena M, Keenan CM, Chiang V, Tan K, Qiao M, Leitl K, Santori A, Pittman QJ, Sharkey KA, Hill MN. Comorbid anxiety-like behavior in a rat model of colitis is mediated by an upregulation of corticolimbic fatty acid amide hydrolase. Neuropsychopharmacology 2021; 46:992-1003. [PMID: 33452437 PMCID: PMC8115350 DOI: 10.1038/s41386-020-00939-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/11/2020] [Accepted: 12/06/2020] [Indexed: 01/29/2023]
Abstract
Peripheral inflammatory conditions, including those localized to the gastrointestinal tract, are highly comorbid with psychiatric disorders such as anxiety and depression. These behavioral symptoms are poorly managed by conventional treatments for inflammatory diseases and contribute to quality of life impairments. Peripheral inflammation is associated with sustained elevations in circulating glucocorticoid hormones, which can modulate central processes, including those involved in the regulation of emotional behavior. The endocannabinoid (eCB) system is exquisitely sensitive to these hormonal changes and is a significant regulator of emotional behavior. The impact of peripheral inflammation on central eCB function, and whether this is related to the development of these behavioral comorbidities remains to be determined. To examine this, we employed the trinitrobenzene sulfonic acid-induced model of colonic inflammation (colitis) in adult, male, Sprague Dawley rats to produce sustained peripheral inflammation. Colitis produced increases in behavioral measures of anxiety and elevations in circulating corticosterone. These alterations were accompanied by elevated hydrolytic activity of the enzyme fatty acid amide hydrolase (FAAH), which hydrolyzes the eCB anandamide (AEA), throughout multiple corticolimbic brain regions. This elevation of FAAH activity was associated with broad reductions in the content of AEA, whose decline was driven by central corticotropin releasing factor type 1 receptor signaling. Colitis-induced anxiety was reversed following acute central inhibition of FAAH, suggesting that the reductions in AEA produced by colitis contributed to the generation of anxiety. These data provide a novel perspective for the pharmacological management of psychiatric comorbidities of chronic inflammatory conditions through modulation of eCB signaling.
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Affiliation(s)
- Haley A. Vecchiarelli
- grid.22072.350000 0004 1936 7697Neuroscience Graduate Program, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB T2N4N1 Canada
| | - Maria Morena
- grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Psychiatry, University of Calgary, Calgary, AB T2N4N1 Canada
| | - Catherine M. Keenan
- grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N4N1 Canada
| | - Vincent Chiang
- grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Psychiatry, University of Calgary, Calgary, AB T2N4N1 Canada
| | - Kaitlyn Tan
- grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Psychiatry, University of Calgary, Calgary, AB T2N4N1 Canada
| | - Min Qiao
- grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Psychiatry, University of Calgary, Calgary, AB T2N4N1 Canada
| | - Kira Leitl
- grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Psychiatry, University of Calgary, Calgary, AB T2N4N1 Canada
| | - Alessia Santori
- grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Psychiatry, University of Calgary, Calgary, AB T2N4N1 Canada
| | - Quentin J. Pittman
- grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N4N1 Canada
| | - Keith A. Sharkey
- grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N4N1 Canada
| | - Matthew N. Hill
- grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB T2N4N1 Canada ,grid.22072.350000 0004 1936 7697Department of Psychiatry, University of Calgary, Calgary, AB T2N4N1 Canada
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10
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Gonçalves de Andrade E, Šimončičová E, Carrier M, Vecchiarelli HA, Robert MÈ, Tremblay MÈ. Microglia Fighting for Neurological and Mental Health: On the Central Nervous System Frontline of COVID-19 Pandemic. Front Cell Neurosci 2021; 15:647378. [PMID: 33737867 PMCID: PMC7961561 DOI: 10.3389/fncel.2021.647378] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 01/15/2021] [Indexed: 12/15/2022] Open
Abstract
Coronavirus disease 2019 (COVID-19) is marked by cardio-respiratory alterations, with increasing reports also indicating neurological and psychiatric symptoms in infected individuals. During COVID-19 pathology, the central nervous system (CNS) is possibly affected by direct severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invasion, exaggerated systemic inflammatory responses, or hypoxia. Psychosocial stress imposed by the pandemic further affects the CNS of COVID-19 patients, but also the non-infected population, potentially contributing to the emergence or exacerbation of various neurological or mental health disorders. Microglia are central players of the CNS homeostasis maintenance and inflammatory response that exert their crucial functions in coordination with other CNS cells. During homeostatic challenges to the brain parenchyma, microglia modify their density, morphology, and molecular signature, resulting in the adjustment of their functions. In this review, we discuss how microglia may be involved in the neuroprotective and neurotoxic responses against CNS insults deriving from COVID-19. We examine how these responses may explain, at least partially, the neurological and psychiatric manifestations reported in COVID-19 patients and the general population. Furthermore, we consider how microglia might contribute to increased CNS vulnerability in certain groups, such as aged individuals and people with pre-existing conditions.
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Affiliation(s)
| | - Eva Šimončičová
- Division of Medical Science, University of Victoria, Victoria, BC, Canada
| | - Micaël Carrier
- Division of Medical Science, University of Victoria, Victoria, BC, Canada.,Axe Neurosciences, Centre de Recherche du CHU de Québec, Université de Laval, Québec City, QC, Canada
| | | | - Marie-Ève Robert
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université de Laval, Québec City, QC, Canada
| | - Marie-Ève Tremblay
- Division of Medical Science, University of Victoria, Victoria, BC, Canada.,Axe Neurosciences, Centre de Recherche du CHU de Québec, Université de Laval, Québec City, QC, Canada.,Neurology and Neurosurgery Department, McGill University, Montréal, QC, Canada.,Department of Molecular Medicine, Université de Laval, Québec City, QC, Canada.,Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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11
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Tubbs JD, Ding J, Baum L, Sham PC. Systemic neuro-dysregulation in depression: Evidence from genome-wide association. Eur Neuropsychopharmacol 2020; 39:1-18. [PMID: 32896454 DOI: 10.1016/j.euroneuro.2020.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 06/10/2020] [Accepted: 08/17/2020] [Indexed: 12/16/2022]
Abstract
Depression is the world's leading cause of disability. Greater understanding of the neurobiological basis of depression is necessary for developing novel treatments with improved efficacy and acceptance. Recently, major advances have been made in the search for genetic variants associated with depression which may help to elucidate etiological mechanisms. The present review has two major objectives. First, we offer a brief review of two major biological systems with strong evidence for involvement in depression pathology: neurotransmitter systems and the stress response. Secondly, we provide a synthesis of the functions of the 269 genes implicated by the most recent genome-wide meta-analysis, supporting the importance of these systems in depression and providing insights into other possible mechanisms involving neurodevelopment, neurogenesis, and neurodegeneration. Our goal is to undertake a broad, preliminary stock-taking of the most recent hypothesis-free findings and examine the weight of the evidence supporting these existing theories and highlighting novel directions. This qualitative review and accompanying gene function table provides a valuable resource and guide for basic and translational researchers, with suggestions for future mechanistic research, leveraging genetics to prioritize studies on the neurobiological processes involved in depression etiology and treatment.
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Affiliation(s)
- Justin D Tubbs
- Department of Psychiatry, The University of Hong Kong, Hong Kong
| | - Jiahong Ding
- Department of Psychiatry, The University of Hong Kong, Hong Kong
| | - Larry Baum
- Department of Psychiatry, The University of Hong Kong, Hong Kong; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong
| | - Pak C Sham
- Department of Psychiatry, The University of Hong Kong, Hong Kong; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong; Centre of PanorOmic Sciences, The University of Hong Kong, Hong Kong.
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12
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Klausing AD, Fukuwatari T, Bucci DJ, Schwarcz R. Stress-induced impairment in fear discrimination is causally related to increased kynurenic acid formation in the prefrontal cortex. Psychopharmacology (Berl) 2020; 237:1931-1941. [PMID: 32215686 PMCID: PMC7308198 DOI: 10.1007/s00213-020-05507-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 03/10/2020] [Indexed: 12/11/2022]
Abstract
RATIONALE Stress is related to cognitive impairments which are observed in most major brain diseases. Prior studies showed that the brain concentration of the tryptophan metabolite kynurenic acid (KYNA) is modulated by stress, and that changes in cerebral KYNA levels impact cognition. However, the link between these phenomena has not been tested directly so far. OBJECTIVES To investigate a possible causal relationship between acute stress, KYNA, and fear discrimination. METHODS Adult rats were exposed to one of three acute stressors-predator odor, restraint, or inescapable foot shocks (ISS)-and KYNA in the prefrontal cortex was measured using microdialysis. Corticosterone was analyzed in a subset of rats. Another cohort underwent a fear discrimination procedure immediately after experiencing stress. Different auditory conditioned stimuli (CSs) were either paired with foot shock (CS+) or were non-reinforced (CS-). One week later, fear was assessed by re-exposing rats to each CS. Finally, to test whether stress-induced changes in KYNA causally impacted fear discrimination, a group of rats that received ISS were pre-treated with the selective KYNA synthesis inhibitor PF-04859989. RESULTS ISS caused the greatest increase in circulating corticosterone levels and raised extracellular KYNA levels by ~ 85%. The two other stressors affected KYNA much less (< 25% increase). Moreover, only rats that received ISS were unable to discriminate between CS+ and CS-. PF-04859989 abolished the stress-induced KYNA increase and also prevented the impairment in fear discrimination in animals that experienced ISS. CONCLUSIONS These findings demonstrate a causal connection between stress-induced KYNA increases and cognitive deficits. Pharmacological manipulation of KYNA synthesis therefore offers a novel approach to modulate cognitive processes in stress-related disorders.
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Affiliation(s)
- Alex D Klausing
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, 55 Wade Avenue, Baltimore, MD, 21228, USA
| | - Tsutomu Fukuwatari
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, 55 Wade Avenue, Baltimore, MD, 21228, USA
- Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga, 522-8533, Japan
| | - David J Bucci
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, USA
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, 55 Wade Avenue, Baltimore, MD, 21228, USA.
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13
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Reduced adolescent risk-assessment and lower nicotinic beta-2 expression in rats exposed to nicotine through lactation by forcedly drinking dams. Neuroscience 2019; 413:64-76. [DOI: 10.1016/j.neuroscience.2019.06.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 06/07/2019] [Accepted: 06/10/2019] [Indexed: 01/06/2023]
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14
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Strzelewicz AR, Ordoñes Sanchez E, Rondón-Ortiz AN, Raneri A, Famularo ST, Bangasser DA, Kentner AC. Access to a high resource environment protects against accelerated maturation following early life stress: A translational animal model of high, medium and low security settings. Horm Behav 2019; 111:46-59. [PMID: 30708031 PMCID: PMC6527488 DOI: 10.1016/j.yhbeh.2019.01.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 12/18/2018] [Accepted: 01/10/2019] [Indexed: 12/21/2022]
Abstract
Early life exposure to a low security setting, characterized by a scarcity of resources and limited food access, increases the risk for psychiatric illness and metabolic dysfunction. We utilized a translational rat model to mimic a low security environment and determined how this manipulation affected offspring behavior, metabolism, and puberty. Because food insecurity in humans is associated with reduced access to healthy food options the "low security" rat manipulation combined a Western diet with exposure to a limited bedding and nesting manipulation (WD-LB). In this setting, dams were provided with limited nesting materials during the pups' early life (P2-P10). This manipulation was contrasted with standard rodent caging (SD) and environmental enrichment (EE), to model "medium security" and "high security" environments, respectively. To determine if transitioning from a low to high security environment improved outcomes, some juvenile WD-LB offspring were exposed to EE. Maternal care was impacted by these environments such that EE dams engaged in high quality care when on the nest, but spent less time on the nest than SD dams. Although WD-LB dams excessively chased their tails, they were very attentive to their pups, perhaps to compensate for limited resources. Offspring exposed to WD-LB only displayed subtle changes in behavior. However, WD-LB exposure resulted in significant metabolic dysfunction characterized by increased body weight, precocious puberty and alterations in the hypothalamic kisspeptin system. These negative effects of WD-LB on puberty and weight regulation were mitigated by EE exposure. Collectively, these studies suggest that both compensatory maternal care and juvenile enrichment can reduce the impact of a low security environment. Moreover, they highlight how utilizing diverse models of resource (in)stability can reveal mechanisms that confer vulnerability and resilience to early life stress.
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Affiliation(s)
- Arielle R Strzelewicz
- School of Pharmacy, Massachusetts College of Pharmacy and Health Sciences, Boston,MA 02115, United States
| | | | - Alejandro N Rondón-Ortiz
- School of Pharmacy, Massachusetts College of Pharmacy and Health Sciences, Boston,MA 02115, United States
| | - Anthony Raneri
- School of Arts & Sciences, Health Psychology Program, Massachusetts College of Pharmacy and Health Sciences, Boston, MA 02115, United States
| | - Sydney T Famularo
- Department of Psychology, Temple University, Philadelphia, PA 19122, United States
| | - Debra A Bangasser
- Department of Psychology, Temple University, Philadelphia, PA 19122, United States
| | - Amanda C Kentner
- School of Arts & Sciences, Health Psychology Program, Massachusetts College of Pharmacy and Health Sciences, Boston, MA 02115, United States.
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15
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The ‘Yin’ and the ‘Yang’ of the kynurenine pathway: excitotoxicity and neuroprotection imbalance in stress-induced disorders. Behav Pharmacol 2019; 30:163-186. [DOI: 10.1097/fbp.0000000000000477] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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16
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Dostal CR, Gamsby NS, Lawson MA, McCusker RH. Glia- and tissue-specific changes in the Kynurenine Pathway after treatment of mice with lipopolysaccharide and dexamethasone. Brain Behav Immun 2018; 69:321-335. [PMID: 29241670 PMCID: PMC5857427 DOI: 10.1016/j.bbi.2017.12.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 12/09/2017] [Accepted: 12/09/2017] [Indexed: 12/31/2022] Open
Abstract
Behavioral symptoms associated with mood disorders have been intimately linked with immunological and psychological stress. Induction of immune and stress pathways is accompanied by increased tryptophan entry into the Kynurenine (Kyn) Pathway as governed by the rate-limiting enzymes indoleamine/tryptophan 2,3-dioxygenases (DO's: Ido1, Ido2, Tdo2). Indeed, elevated DO expression is associated with inflammation- and stress-related depression symptoms. Here we examined central (brain, astrocyte and microglia) and peripheral (lung, liver and spleen) DO expression in mice treated intraperitoneally with lipopolysaccharide (LPS) and dexamethasone (DEX) to model the response of the Kyn Pathway to inflammation and glucocorticoids. LPS-induced expression of cytokines in peripheral tissues was attenuated by DEX, confirming inflammatory and anti-inflammatory responses, respectively. Increased Kyn levels following LPS and DEX administration verified Kyn Pathway activation. Expression of multiple mRNA isoforms for each DO, which we have shown to be differentially utilized and regulated, were quantified including reference/full-length (FL) and variant (v) transcripts. LPS increased Ido1-FL in brain (∼1000-fold), a response paralleled by increased expression in both astrocytes and microglia. Central Ido1-FL was not changed by DEX; however, LPS-induced Ido1-FL was decreased by DEX in peripheral tissues. In contrast, DEX increased Ido1-v1 expression by astrocytes and microglia, but not peripheral tissues. In comparison, brain Ido2 was minimally induced by LPS or DEX. Uniquely, Ido2-v6 was LPS- and DEX-inducible in astrocytes, suggesting a unique role for astrocytes in response to inflammation and glucocorticoids. Only DEX increased central Tdo2 expression; however, peripheral Tdo2 was upregulated by either LPS or DEX. In summary, specific DO isoforms are increased by LPS and DEX, but LPS-dependent Ido1 and Ido2 induction are attenuated by DEX only in the periphery indicating that elevated DO expression and Kyn production within the brain can occur independent of the periphery. These findings demonstrate a plausible interaction between immune activation and glucocorticoids associated with depression.
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Affiliation(s)
- Carlos R. Dostal
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States,Medical Scholars Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States,Integrative Immunology and Behavior Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States
| | - Nicolaus S. Gamsby
- School of Earth, Society and Environment, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States
| | - Marcus A. Lawson
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States,Integrative Immunology and Behavior Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States,Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States
| | - Robert H. McCusker
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States,Integrative Immunology and Behavior Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States,Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States,Department of Pathology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States
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17
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Dostal CR, Carson Sulzer M, Kelley KW, Freund GG, M cCusker RH. Glial and tissue-specific regulation of Kynurenine Pathway dioxygenases by acute stress of mice. Neurobiol Stress 2017; 7:1-15. [PMID: 29520368 PMCID: PMC5840960 DOI: 10.1016/j.ynstr.2017.02.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 01/10/2017] [Accepted: 02/07/2017] [Indexed: 01/11/2023] Open
Abstract
Stressors activate the hypothalamic-pituitary-adrenal (HPA) axis and immune system eliciting changes in cognitive function, mood and anxiety. An important link between stress and altered behavior is stimulation of the Kynurenine Pathway which generates neuroactive and immunomodulatory kynurenines. Tryptophan entry into this pathway is controlled by rate-limiting indoleamine/tryptophan 2,3-dioxygenases (DOs: Ido1, Ido2, Tdo2). Although implicated as mediating changes in behavior, detecting stress-induced DO expression has proven inconsistent. Thus, C57BL/6J mice were used to characterize DO expression in brain-regions, astrocytes and microglia to characterize restraint-stress-induced DO expression. Stress increased kynurenine in brain and plasma, demonstrating increased DO activity. Of three Ido1 transcripts, only Ido1-v1 expression was increased by stress and within astrocytes, not microglia, indicating transcript- and glial-specificity. Stress increased Ido1-v1 only in frontal cortex and hypothalamus, indicating brain-region specificity. Of eight Ido2 transcripts, Ido2-v3 expression was increased by stress, again only within astrocytes. Likewise, stress increased Tdo2-FL expression in astrocytes, not microglia. Interestingly, Ido2 and Tdo2 transcripts were not correspondingly induced in Ido1-knockout (Ido1KO) mice, suggesting that Ido1 is necessary for the central DO response to acute stress. Unlike acute inflammatory models resulting in DO induction within microglia, only astrocyte DO expression was increased by acute restraint-stress, defining their unique role during stress-dependent activation of the Kynurenine Pathway.
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Affiliation(s)
- Carlos R. Dostal
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Medical Scholars Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Megan Carson Sulzer
- School of Molecular and Cellular Biology, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Keith W. Kelley
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Animal Sciences, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Pathology, University of Illinois at Urbana-Champaign, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Gregory G. Freund
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Animal Sciences, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Pathology, University of Illinois at Urbana-Champaign, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Robert H. McCusker
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Animal Sciences, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Pathology, University of Illinois at Urbana-Champaign, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
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18
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Psychosocial stress on neuroinflammation and cognitive dysfunctions in Alzheimer's disease: the emerging role for microglia? Neurosci Biobehav Rev 2017; 77:148-164. [PMID: 28185874 DOI: 10.1016/j.neubiorev.2017.01.046] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 01/20/2017] [Accepted: 01/31/2017] [Indexed: 01/22/2023]
Abstract
Chronic psychosocial stress is increasingly recognized as a risk factor for late-onset Alzheimer's disease (LOAD) and associated cognitive deficits. Chronic stress also primes microglia and induces inflammatory responses in the adult brain, thereby compromising synapse-supportive roles of microglia and deteriorating cognitive functions during aging. Substantial evidence demonstrates that failure of microglia to clear abnormally accumulating amyloid-beta (Aβ) peptide contributes to neuroinflammation and neurodegeneration in AD. Moreover, genome-wide association studies have linked variants in several immune genes, such as TREM2 and CD33, the expression of which in the brain is restricted to microglia, with cognitive dysfunctions in LOAD. Thus, inflammation-promoting chronic stress may create a vicious cycle of aggravated microglial dysfunction accompanied by increased Aβ accumulation, collectively exacerbating neurodegeneration. Surprisingly, however, little is known about whether and how chronic stress contributes to microglia-mediated neuroinflammation that may underlie cognitive impairments in AD. This review aims to summarize the currently available clinical and preclinical data and outline potential molecular mechanisms linking stress, microglia and neurodegeneration, to foster future research in this field.
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Matsuoka K, Kato K, Takao T, Ogawa M, Ishii Y, Shimizu F, Masuda J, Takada A. Concentrations of various tryptophan metabolites are higher in patients with diabetes mellitus than in healthy aged male adults. Diabetol Int 2016; 8:69-75. [PMID: 30603309 DOI: 10.1007/s13340-016-0282-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/31/2016] [Indexed: 10/21/2022]
Abstract
Tryptophan metabolites in plasma samples from 20 male subjects with type 2 diabetes mellitus (T2DM) and 20 nondiabetic reference males were analyzed by ultra high performance liquid chromatography. Tryptophan levels in the diabetic subjects were significantly lower than those in nondiabetic subjects. The concentrations of 5-hydroxytryptophan, 5-hydroxyindoleacetic acid, kynurenic acid, 3-hydroxykynurenine, 3-hydroxyanthranilic acid, and xanthurenic acid were found to be higher in the diabetic patients. When the diabetic patients were divided into higher- and lower-tryptophan groups, the concentrations of 5-hydroxytryptophan, indole-3-acetic acid, kynurenine, 5-hydroxykynurenine, and kynurenic acid were found to be higher in the diabetic patients with higher tryptophan levels. However, diabetic patients with lower plasma tryptophan levels had higher levels of 5-hydroxyindoleacetic acid than the patients with higher tryptophan levels. These results suggest that tryptophan was metabolized more in T2DM patients than in nondiabetic subjects. In the kynurenine pathway, the degradation of tryptophan seems to be accelerated in patients with higher plasma levels of tryptophan than in patients with lower levels of tryptophan. In the serotonin pathway, when the level of tryptophan is low, the conversion of serotonin to 5-hydroxyindoleacetic acid appears to be accelerated. In conclusion, our results suggest that T2DM patients may be exposed to stress constantly.
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Affiliation(s)
| | - Kiyoe Kato
- Medical Services, Saiseikai Shibuya Clinic, Tokyo, Japan
| | - Tetsuya Takao
- Faculty of Human Life and Environmental Sciences, Showa Womens University, Tokyo, Japan
| | - Mutsumi Ogawa
- Faculty of Human Life and Environmental Sciences, Showa Womens University, Tokyo, Japan
| | - Yukie Ishii
- Faculty of Human Life and Environmental Sciences, Showa Womens University, Tokyo, Japan
| | - Fumiko Shimizu
- Faculty of Human Life and Environmental Sciences, Showa Womens University, Tokyo, Japan
| | - Junichi Masuda
- 3Global Application Development Center, Shimadzu Corporation, Yokohama, Kanagawaken Japan
| | - Akikazu Takada
- NPO "International Projects on Food and Health", Sumidaku Ishiwara 1-30-6-802, Tokyo, 130-0011 Japan
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