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González Olmo BM, Bettes MN, DeMarsh JW, Zhao F, Askwith C, Barrientos RM. Short-term high-fat diet consumption impairs synaptic plasticity in the aged hippocampus via IL-1 signaling. NPJ Sci Food 2023; 7:35. [PMID: 37460765 DOI: 10.1038/s41538-023-00211-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 07/06/2023] [Indexed: 07/20/2023] Open
Abstract
More Americans are consuming diets higher in saturated fats and refined sugars than ever before. These trends could have serious consequences for the older population because high-fat diet (HFD) consumption, known to induce neuroinflammation, has been shown to accelerate and aggravate memory declines. We have previously demonstrated that short-term HFD consumption, which does not evoke obesity-related comorbidities, produced profound impairments to hippocampal-dependent memory in aged rats. These impairments were precipitated by increases in proinflammatory cytokines, primarily interleukin-1 beta (IL-1β). Here, we explored the extent to which short-term HFD consumption disrupts hippocampal synaptic plasticity, as measured by long-term potentiation (LTP), in young adult and aged rats. We demonstrated that (1) HFD disrupted late-phase LTP in the hippocampus of aged, but not young adult rats, (2) HFD did not disrupt early-phase LTP, and (3) blockade of the IL-1 receptor rescued L-LTP in aged HFD-fed rats. These findings suggest that hippocampal memory impairments in aged rats following HFD consumption occur through the deterioration of synaptic plasticity and that IL-1β is a critical driver of that deterioration.
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Affiliation(s)
- Brigitte M González Olmo
- Department of Biomedical Education & Anatomy, Ohio State University, Columbus, OH, USA
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA
| | - Menaz N Bettes
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA
| | - James W DeMarsh
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA
| | - Fangli Zhao
- Department of Neuroscience, The Ohio State University, Columbus, OH, USA
| | - Candice Askwith
- Department of Neuroscience, The Ohio State University, Columbus, OH, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA.
- Department of Neuroscience, The Ohio State University, Columbus, OH, USA.
- Department of Psychiatry and Behavioral Health, Ohio State University, Columbus, OH, USA.
- Chronic Brain Injury Program, The Ohio State University, Columbus, OH, USA.
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2
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Butler MJ, Sengupta S, Muscat SM, Amici SA, Biltz RG, Deems NP, Dravid P, Mackey-Alfonso S, Ijaz H, Bettes MN, Godbout JP, Kapoor A, Guerau-de-Arellano M, Barrientos RM. CD8 + T cells contribute to diet-induced memory deficits in aged male rats. Brain Behav Immun 2023; 109:235-250. [PMID: 36764399 PMCID: PMC10124165 DOI: 10.1016/j.bbi.2023.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/27/2023] [Accepted: 02/03/2023] [Indexed: 02/11/2023] Open
Abstract
We have previously shown that short-term (3-day) high fat diet (HFD) consumption induces a neuroinflammatory response and subsequent impairment of long-term memory in aged, but not young adult, male rats. However, the immune cell phenotypes driving this proinflammatory response are not well understood. Previously, we showed that microglia isolated from young and aged rats fed a HFD express similar levels of priming and proinflammatory transcripts, suggesting that additional factors may drive the exaggerated neuroinflammatory response selectively observed in aged HFD-fed rats. It is established that T cells infiltrate both the young and especially the aged central nervous system (CNS) and contribute to immune surveillance of the parenchyma. Thus, we investigated the modulating role of short-term HFD on T cell presence in the CNS in aged rats using bulk RNA sequencing and flow cytometry. RNA sequencing results indicate that aging and HFD altered the expression of genes and signaling pathways associated with T cell signaling, immune cell trafficking, and neuroinflammation. Moreover, flow cytometry data showed that aging alone increased CD4+ and CD8+ T cell presence in the brain and that CD8+, but not CD4+, T cells were further increased in aged rats fed a HFD. Based on these data, we selectively depleted circulating CD8+ T cells via an intravenous injection of an anti-CD8 antibody in aged rats prior to 3 days of HFD to infer the functional role these cells may be playing in long-term memory and neuroinflammation. Results indicate that peripheral depletion of CD8+ T cells lowered hippocampal cytokine levels and prevented the HFD-induced i) increase in brain CD8+ T cells, ii) memory impairment, and iii) alterations in pre- and post-synaptic structures in the hippocampus and amygdala. Together, these data indicate a substantial role for CD8+ T cells in mediating diet-induced memory impairments in aged male rats.
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Affiliation(s)
- Michael J Butler
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, USA.
| | - Shouvonik Sengupta
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Stephanie M Muscat
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Stephanie A Amici
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA
| | - Rebecca G Biltz
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Nicholas P Deems
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Piyush Dravid
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Sabrina Mackey-Alfonso
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Haanya Ijaz
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Menaz N Bettes
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Jonathan P Godbout
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA; Chronic Brain Injury Program, The Ohio State University, Columbus, OH 43210, USA
| | - Amit Kapoor
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Mireia Guerau-de-Arellano
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA; Chronic Brain Injury Program, The Ohio State University, Columbus, OH 43210, USA
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3
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Muscat SM, Deems NP, Butler MJ, Scaria EA, Bettes MN, Cleary SP, Bockbrader RH, Maier SF, Barrientos RM. Selective TLR4 Antagonism Prevents and Reverses Morphine-Induced Persistent Postoperative Cognitive Dysfunction, Dysregulation of Synaptic Elements, and Impaired BDNF Signaling in Aged Male Rats. J Neurosci 2023; 43:155-172. [PMID: 36384680 PMCID: PMC9838714 DOI: 10.1523/jneurosci.1151-22.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 11/07/2022] [Accepted: 11/10/2023] [Indexed: 11/18/2022] Open
Abstract
Perioperative neurocognitive disorders (PNDs) are characterized by confusion, difficulty with executive function, and episodic memory impairment in the hours to months following a surgical procedure. Postoperative cognitive dysfunction (POCD) represents such impairments that last beyond 30 d postsurgery and is associated with increased risk of comorbidities, progression to dementia, and higher mortality. While it is clear that neuroinflammation plays a key role in PND development, what factors underlie shorter self-resolving versus persistent PNDs remains unclear. We have previously shown that postoperative morphine treatment extends POCD from 4 d (without morphine) to at least 8 weeks (with morphine) in aged male rats, and that this effect is likely dependent on the proinflammatory capabilities of morphine via activation of toll-like receptor 4 (TLR4). Here, we extend these findings to show that TLR4 blockade, using the selective TLR4 antagonist lipopolysaccharide from the bacterium Rhodobacter sphaeroides (LPS-RS Ultrapure), ameliorates morphine-induced POCD in aged male rats. Using either a single central preoperative treatment or a 1 week postoperative central treatment regimen, we demonstrate that TLR4 antagonism (1) prevents and reverses the long-term memory impairment associated with surgery and morphine treatment, (2) ameliorates morphine-induced dysregulation of the postsynaptic proteins postsynaptic density 95 and synaptopodin, (3) mitigates reductions in mature BDNF, and (4) prevents decreased activation of the BDNF receptor TrkB (tropomyosin-related kinase B), all at 4 weeks postsurgery. We also reveal that LPS-RS Ultrapure likely exerts its beneficial effects by preventing endogenous danger signal HMGB1 (high-mobility group box 1) from activating TLR4, rather than by blocking continuous activation by morphine or its metabolites. These findings suggest TLR4 as a promising therapeutic target to prevent or treat PNDs.SIGNIFICANCE STATEMENT With humans living longer than ever, it is crucial that we identify mechanisms that contribute to aging-related vulnerability to cognitive impairment. Here, we show that the innate immune receptor toll-like receptor 4 (TLR4) is a key mediator of cognitive dysfunction in aged rodents following surgery and postoperative morphine treatment. Inhibition of TLR4 both prevented and reversed surgery plus morphine-associated memory impairment, dysregulation of synaptic elements, and reduced BDNF signaling. Together, these findings implicate TLR4 in the development of postoperative cognitive dysfunction, providing mechanistic insight and novel therapeutic targets for the treatment of cognitive impairments following immune challenges such as surgery in older individuals.
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Affiliation(s)
- Stephanie M Muscat
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio 43210
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, Ohio 43210
| | - Nicholas P Deems
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio 43210
- Neuroscience Graduate Program, The Ohio State University, Columbus, Ohio 43210
| | - Michael J Butler
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio 43210
| | - Emmanuel A Scaria
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio 43210
| | - Menaz N Bettes
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio 43210
| | - Sean P Cleary
- Campus Chemical Instrumentation Center, The Ohio State University, Columbus, Ohio 43210
| | - Ross H Bockbrader
- Pharmaceutical Sciences Graduate Program, Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio 43210
| | - Steven F Maier
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, Colorado 80309
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio 43210
- Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, Ohio 43210
- Department of Neuroscience, The Ohio State University, Columbus, Ohio 43210
- Chronic Brain Injury Program, The Ohio State University, Columbus, Ohio 43210
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Wang WZ, Liu X, Yang ZY, Wang YZ, Lu HT. Diffusion tensor imaging of the hippocampus reflects the severity of hippocampal injury induced by global cerebral ischemia/reperfusion injury. Neural Regen Res 2021; 17:838-844. [PMID: 34472484 PMCID: PMC8530111 DOI: 10.4103/1673-5374.322468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
At present, predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury (GCI/RI) is a clinical problem. After such an injury, clinical indicators that can directly reflect neurological dysfunction are lacking. The change in hippocampal microstructure is the key to memory formation and consolidation. Diffusion tensor imaging is a highly sensitive tool for visualizing injury to hippocampal microstructure. Although hippocampal microstructure, brain-derived neurotrophic factor (BDNF), and tropomyosin-related kinase B (TrkB) levels are closely related to nerve injury and the repair process after GCI/RI, whether these indicators can reflect the severity of such hippocampal injury remains unknown. To address this issue, we established rat models of GCI/RI using the four-vessel occlusion method. Diffusion tensor imaging parameters, BDNF, and TrkB levels were correlated with modified neurological severity scores. The results revealed that after GCI/RI, while neurological function was not related to BDNF and TrkB levels, it was related to hippocampal fractional anisotropy. These findings suggest that hippocampal fractional anisotropy can reflect the severity of hippocampal injury after global GCI/RI. The study was approved by the Institutional Animal Care and Use Committee of Capital Medical University, China (approval No. AEEI-2015-139) on November 9, 2015.
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Affiliation(s)
- Wen-Zhu Wang
- China Rehabilitation Science Institute, School of Rehabilitation Medicine, Capital Medical University, Beijing Bo'ai Hospital, China Rehabilitation Research Center; Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Xu Liu
- Department of Rehabilitation Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zheng-Yi Yang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Yi-Zheng Wang
- China Rehabilitation Science Institute, School of Rehabilitation Medicine, Capital Medical University, Beijing Bo'ai Hospital, China Rehabilitation Research Center, Beijing, China
| | - Hai-Tao Lu
- China Rehabilitation Science Institute, School of Rehabilitation Medicine, Capital Medical University, Beijing Bo'ai Hospital, China Rehabilitation Research Center, Beijing, China
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Muscat SM, Barrientos RM. The Perfect Cytokine Storm: How Peripheral Immune Challenges Impact Brain Plasticity & Memory Function in Aging. Brain Plast 2021; 7:47-60. [PMID: 34631420 PMCID: PMC8461734 DOI: 10.3233/bpl-210127] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Precipitous declines in cognitive function can occur in older individuals following a variety of peripheral immune insults, such as surgery, infection, injury, and unhealthy diet. Aging is associated with numerous changes to the immune system that shed some light on why this abrupt cognitive deterioration may occur. Normally, peripheral-to-brain immune signaling is tightly regulated and advantageous; communication between the two systems is bi-directional, via either humoral or neural routes. Following an immune challenge, production, secretion, and translocation of cytokines into the brain is critical to the development of adaptive sickness behaviors. However, aging is normally associated with neuroinflammatory priming, notably microglial sensitization. Microglia are the brain's innate immune cells and become sensitized with advanced age, such that upon immune stimulation they will mount more exaggerated neuroimmune responses. The resultant elevation of pro-inflammatory cytokine expression, namely IL-1β, has profound effects on synaptic plasticity and, consequentially, cognition. In this review, we (1) investigate the processes which lead to aberrantly elevated inflammatory cytokine expression in the aged brain and (2) examine the impact of the pro-inflammatory cytokine IL-1β on brain plasticity mechanisms, including its effects on BDNF, AMPA and NMDA receptor-mediated long-term potentiation.
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Affiliation(s)
- Stephanie M Muscat
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
- Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, USA
- Department of Neuroscience, The Ohio State University, Columbus, OH, USA
- Chronic Brain Injury Program, Discovery Themes Initiative, The Ohio State University, Columbus, OH, USA
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6
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Ji MH, He X, Shen JC, Yang JJ. Aging-Related Neural Disruption Might Predispose to Postoperative Cognitive Impairment Following Surgical Trauma. J Alzheimers Dis 2021; 81:1685-1699. [PMID: 33967044 DOI: 10.3233/jad-201590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Accumulating evidence has demonstrated that aging is associated with an exaggerated response to surgical trauma together with cognitive impairments. This has significant implications for the development of clinical phenotype such as perioperative neurocognitive disorders (PND), which is a common complication following surgery, especially for the elderly. However, the mechanism by which aging brain is vulnerable to surgical trauma remains to be elucidated. OBJECTIVE To test whether age-related alterations in hippocampal network activities contribute to increased risk of PND following surgery. METHODS Thirty-two adult and seventy-two aged male C57BL/6 mice undergone sevoflurane anesthesia and exploratory laparotomy were used to mimic human abdominal surgery. For the interventional study, mice were treated with minocycline. Behavioral tests were performed post-surgery with open field, novel object recognition and fear conditioning tests, respectively. The brain tissues were then harvested and subjected to biochemistry studies. Local field potential (LFP) recording was performed in another separate experiment. RESULTS Aged mice displayed signs of neuroinflammation, as reflected by significantly increased proinflammatory mediators in the hippocampus. Also, aged mice displayed persistently decreased oscillation activities under different conditions, both before and after surgery. Further correlation analysis suggested that theta power was positively associated with time with novel object, while γ oscillation activity was positively associated with freezing time to context. Of note, downregulation of neuroinflammation by microglia inhibitor minocycline reversed some of these abnormities. CONCLUSION Our study highlights that age-related hippocampal oscillation dysregulation increases the risk of PND incidence, which might provide diagnostic/prognostic biomarkers for PND and possible other neurodegenerative diseases.
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Affiliation(s)
- Mu-Huo Ji
- Department of Anesthesiology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xue He
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Jin-Chun Shen
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Jian-Jun Yang
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Muscat SM, Deems NP, D'Angelo H, Kitt MM, Grace PM, Andersen ND, Silverman SN, Rice KC, Watkins LR, Maier SF, Barrientos RM. Postoperative cognitive dysfunction is made persistent with morphine treatment in aged rats. Neurobiol Aging 2021; 98:214-224. [PMID: 33341652 PMCID: PMC7870544 DOI: 10.1016/j.neurobiolaging.2020.11.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/21/2020] [Accepted: 11/07/2020] [Indexed: 12/18/2022]
Abstract
Postoperative cognitive dysfunction (POCD) is the collection of cognitive impairments, lasting days to months, experienced by individuals following surgery. Persistent POCD is most commonly experienced by older individuals and is associated with a greater vulnerability to developing Alzheimer's disease, but the underlying mechanisms are not known. It is known that laparotomy (exploratory abdominal surgery) in aged rats produces memory impairments for 4 days. Here we report that postsurgical treatment with morphine extends this deficit to at least 2 months while having no effects in the absence of surgery. Indeed, hippocampal-dependent long-term memory was impaired 2, 4, and 8 weeks postsurgery only in aged, morphine-treated rats. Short-term memory remained intact. Morphine is known to have analgesic effects via μ-opioid receptor activation and neuroinflammatory effects through Toll-like receptor 4 activation. Here we demonstrate that persistent memory deficits were mediated independently of the μ-opioid receptor, suggesting that they were evoked through a neuroinflammatory mechanism and unrelated to pain modulation. In support of this, aged, laparotomized, and morphine-treated rats exhibited increased gene expression of various proinflammatory markers (IL-1β, IL-6, TNFα, NLRP3, HMGB1, TLR2, and TLR4) in the hippocampus at the 2-week time point. Furthermore, central blockade of IL-1β signaling with the specific IL-1 receptor antagonist (IL-1RA), at the time of surgery, completely prevented the memory impairment. Finally, synaptophysin and PSD95 gene expression were significantly dysregulated in the hippocampus of aged, laparotomized, morphine-treated rats, suggesting that impaired synaptic structure and/or function may play a key role in this persistent deficit. This instance of long-term memory impairment following surgery closely mirrors the timeline of persistent POCD in humans and may be useful for future treatment discoveries.
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Affiliation(s)
- Stephanie M Muscat
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Nicholas P Deems
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Heather D'Angelo
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Meagan M Kitt
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Peter M Grace
- Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Nathan D Andersen
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Shaelyn N Silverman
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Kenner C Rice
- Drug Design and Synthesis Section, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Linda R Watkins
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Steven F Maier
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA; Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA; Chronic Brain Injury Program, Discovery Themes Initiative, The Ohio State University, Columbus, OH, USA.
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Evolution of the Human Diet and Its Impact on Gut Microbiota, Immune Responses, and Brain Health. Nutrients 2021; 13:nu13010196. [PMID: 33435203 PMCID: PMC7826636 DOI: 10.3390/nu13010196] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/30/2020] [Accepted: 01/07/2021] [Indexed: 12/18/2022] Open
Abstract
The relatively rapid shift from consuming preagricultural wild foods for thousands of years, to consuming postindustrial semi-processed and ultra-processed foods endemic of the Western world less than 200 years ago did not allow for evolutionary adaptation of the commensal microbial species that inhabit the human gastrointestinal (GI) tract, and this has significantly impacted gut health. The human gut microbiota, the diverse and dynamic population of microbes, has been demonstrated to have extensive and important interactions with the digestive, immune, and nervous systems. Western diet-induced dysbiosis of the gut microbiota has been shown to negatively impact human digestive physiology, to have pathogenic effects on the immune system, and, in turn, cause exaggerated neuroinflammation. Given the tremendous amount of evidence linking neuroinflammation with neural dysfunction, it is no surprise that the Western diet has been implicated in the development of many diseases and disorders of the brain, including memory impairments, neurodegenerative disorders, and depression. In this review, we discuss each of these concepts to understand how what we eat can lead to cognitive and psychiatric diseases.
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9
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Alam JJ, Krakovsky M, Germann U, Levy A. Continuous administration of a p38α inhibitor during the subacute phase after transient ischemia-induced stroke in the rat promotes dose-dependent functional recovery accompanied by increase in brain BDNF protein level. PLoS One 2020; 15:e0233073. [PMID: 33275615 PMCID: PMC7717516 DOI: 10.1371/journal.pone.0233073] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 11/20/2020] [Indexed: 12/17/2022] Open
Abstract
There is unmet need for effective stroke therapies. Numerous neuroprotection attempts for acute cerebral ischemia have failed and as a result there is growing interest in developing therapies to promote functional recovery through increasing synaptic plasticity. For this research study, we hypothesized that in addition to its previously reported role in mediating cell death during the acute phase, the alpha isoform of p38 mitogen-activated protein kinase, p38α, may also contribute to interleukin-1β-mediated impairment of functional recovery during the subacute phase after acute ischemic stroke. Accordingly, an oral, brain-penetrant, small molecule p38α inhibitor, neflamapimod, was evaluated as a subacute phase stroke treatment to promote functional recovery. Neflamapimod administration to rats after transient middle cerebral artery occlusion at two dose levels was initiated outside of the previously characterized therapeutic window for neuroprotection of less than 24 hours for p38α inhibitors. Six-week administration of neflamapimod, starting at 48 hours after reperfusion, significantly improved behavioral outcomes assessed by the modified neurological severity score at Week 4 and at Week 6 post stroke in a dose-dependent manner. Neflamapimod demonstrated beneficial effects on additional measures of sensory and motor function. It also resulted in a dose-related increase in brain-derived neurotrophic factor (BDNF) protein levels, a previously reported potential marker of synaptic plasticity that was measured in brain homogenates at sacrifice. Taken together with literature evidence on the role of p38α-dependent suppression by interleukin-1β of BDNF-mediated synaptic plasticity and BDNF production, our findings support a mechanistic model in which inhibition of p38α promotes functional recovery after ischemic stroke by blocking the deleterious effects of interleukin-1β on synaptic plasticity. The dose-related in vivo efficacy of neflamapimod offers the possibility of having a therapy for stroke that could be initiated outside the short time window for neuroprotection and for improving recovery after a completed stroke.
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Affiliation(s)
- John J. Alam
- EIP Pharma, Inc., Boston, Massachusetts, United States of America
- * E-mail:
| | | | - Ursula Germann
- EIP Pharma, Inc., Boston, Massachusetts, United States of America
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Muscat SM, Barrientos RM. Lifestyle modifications with anti-neuroinflammatory benefits in the aging population. Exp Gerontol 2020; 142:111144. [PMID: 33152515 DOI: 10.1016/j.exger.2020.111144] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/18/2020] [Accepted: 10/28/2020] [Indexed: 01/03/2023]
Abstract
Aging-associated microglial priming results in the potential for an exaggerated neuroinflammatory response to a subsequent inflammatory challenge in regions of the brain known to support learning and memory. This excessive neuroinflammation in the aging brain is known to occur following a variety of peripheral insults, including infection and surgery, where it has been associated with precipitous declines in cognition and memory. As the average lifespan increases worldwide, identifying interventions to prevent and treat aging-associated excessive neuroinflammation and ensuing cognitive impairments is of critical importance. Lifestyle has emerged as a potential non-pharmacological target in this endeavor. Here, we review important and recent preclinical and clinical literature demonstrating the anti-inflammatory effects of lifestyle modifications such as exercise, diet, and environmental enrichment in the context of aging and memory. Importantly, we focus on research indicating that these lifestyle modifications do not need to be lifelong, suggesting that such interventions may be efficacious in the prevention and treatment of aging- and neuroinflammation-associated cognitive impairment, even when initiated in older age.
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Affiliation(s)
- Stephanie M Muscat
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA; Chronic Brain Injury Program, Discovery Themes Initiative, The Ohio State University, Columbus, OH, USA.
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11
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Bustamante AC, Opron K, Ehlenbach WJ, Larson EB, Crane PK, Keene CD, Standiford TJ, Singer BH. Transcriptomic Profiles of Sepsis in the Human Brain. Am J Respir Crit Care Med 2020; 201:861-863. [PMID: 31940219 PMCID: PMC7124721 DOI: 10.1164/rccm.201909-1713le] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
| | | | | | - Eric B. Larson
- Kaiser Permanente Washington Health Research InstituteSeattle, Washingtonand
| | - Paul K. Crane
- University of Washington School of MedicineSeattle, Washington
| | - C. Dirk Keene
- University of Washington School of MedicineSeattle, Washington
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Caracci F, Harary J, Simkovic S, Pasinetti GM. Grape-Derived Polyphenols Ameliorate Stress-Induced Depression by Regulating Synaptic Plasticity. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:1808-1815. [PMID: 31532659 DOI: 10.1021/acs.jafc.9b01970] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Major depressive disorder (MDD) is associated with stress-induced immune dysregulation and reduced brain-derived neurotrophic factor (BDNF) levels in sensitive brain regions associated with depression. Elevated levels of proinflammatory cytokines and reduced BDNF levels lead to impaired synaptic plasticity mechanisms that contribute to the pathophysiology of MDD. There is accumulating evidence that the administration of polyphenols at doses ranging from 5 to 180 mg/kg of body weight can normalize elevated levels of proinflammatory cytokines and abnormal levels of BDNF and, thus, restore impaired synaptic plasticity mechanisms that mediate depressive behavior in animal models of stress. This review will focus on the mechanisms by which grape-derived polyphenols normalize impaired synaptic plasticity and reduce depressive behavior in animal models of stress.
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Affiliation(s)
- Francesca Caracci
- Department of Neurology , Icahn School of Medicine at Mount Sinai , 1 Gustave L. Levy Place , Box 1137, New York , New York 10029 , United States
| | - Joyce Harary
- Department of Neurology , Icahn School of Medicine at Mount Sinai , 1 Gustave L. Levy Place , Box 1137, New York , New York 10029 , United States
| | - Sherry Simkovic
- Department of Neurology , Icahn School of Medicine at Mount Sinai , 1 Gustave L. Levy Place , Box 1137, New York , New York 10029 , United States
| | - Giulio Maria Pasinetti
- Department of Neurology , Icahn School of Medicine at Mount Sinai , 1 Gustave L. Levy Place , Box 1137, New York , New York 10029 , United States
- Geriatrics Research, Education and Clinical Center , JJ Peters VA Medical Center , Bronx , New York 10468 , United States
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Carr ZJ, Miller L, Ruiz-Velasco V, Kunselman AR, Karamchandani K. In a Model of Neuroinflammation Designed to Mimic Delirium, Quetiapine Reduces Cortisol Secretion and Preserves Reversal Learning in the Attentional Set Shifting Task. J Neuroimmune Pharmacol 2019; 14:383-390. [PMID: 31119596 DOI: 10.1007/s11481-019-09857-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 05/13/2019] [Indexed: 01/21/2023]
Abstract
Quetiapine, an atypical antipsychotic medication has lacked pre-clinical validation for its purported benefits in the treatment of delirium. This laboratory investigation examined the effects of quetiapine on the attentional set shifting task (ASST), a measure of cognitive flexibility and executive functioning, in a rodent model of lipopolysaccharide (LPS) mediated neuroinflammation. 19 Sprague Dawley female rats were randomly selected to receive intraperitoneal placebo (N = 5), LPS and placebo (N = 7) or LPS and quetiapine (n = 7) and performed the ASST. We measured trials to criterion, errors, non-locomotion episodes and latency to criterion, serum cortisol and tumor necrosis factor alpha (TNF-α) levels. TNF-α levels were not different between groups at 24 h. Cortisol levels in the LPS + Quetiapine group were reduced compared to LPS + Placebo (P < 0.001) and did not differ from the placebo group (P = 0.15). Analysis between LPS + Quetiapine and LPS + Placebo treated rats demonstrated improvement in the compound discrimination reversal (CD Rev1) (P = 0.016) and the intra-dimensional reversal (ID Rev2) (P = 0.007) discriminations on trials to criterion. LPS + Quetiapine treated rats had fewer errors than LPS + Placebo treated animals in the compound discrimination (CD) (P = 0.007), CD Rev1 (P = 0.005), ID Rev2 (P < 0.001) discriminations. There was no difference in non-locomotion frequency or latency to criterion between the three groups in all discriminations (P > 0.0167). We demonstrated preserved reversal learning, no effect on attentional set shifting and normalized cortisol levels in quetiapine-treated rats in this neuroinflammatory model of delirium. This suggests that quetiapine's beneficial effects in delirium may be related to the preservation of reversal learning and potential downstream effects related to reduction in cortisol production. Graphical Abstract.
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Affiliation(s)
- Zyad J Carr
- Department of Anesthesiology & Perioperative Medicine, Penn State Health Milton S. Hershey Medical Center, Hershey, PA, 17033, USA. .,Department of Medicine, Penn State Health Milton S. Hershey Medical Center, Hershey, PA, 17033, USA. .,Department of Anesthesiology & Perioperative Medicine, H187, 500 University Dr., Hershey, PA, 17078, USA.
| | - Lauren Miller
- Department of Anesthesiology & Perioperative Medicine, Penn State Health Milton S. Hershey Medical Center, Hershey, PA, 17033, USA
| | - Victor Ruiz-Velasco
- Department of Anesthesiology & Perioperative Medicine, Penn State Health Milton S. Hershey Medical Center, Hershey, PA, 17033, USA.,Department of Neural and Behavioral Sciences, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Allen R Kunselman
- Department of Public Health Sciences, Penn State College of Medicine, Penn State Health Milton S. Hershey Medical Center, Hershey, PA, 17033, USA
| | - Kunal Karamchandani
- Department of Anesthesiology & Perioperative Medicine, Penn State Health Milton S. Hershey Medical Center, Hershey, PA, 17033, USA
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Abstract
Survivors of sepsis and other forms of critical illness frequently experience significant and disabling cognitive and affective disorders. Inflammation, ischemia, and glial cell dysfunction contribute to this persistent brain injury. In this issue of the JCI, Hippensteel et al. show that endothelial injury in animal models of sepsis or endotoxemia leads to shedding of heparan fragments from the endothelial glycocalyx. These fragments directly sequester brain-derived neurotrophic factor and impair hippocampal long-term potentiation, an electrophysiologic correlate of memory. The authors further explore the specific characteristics of heparan fragments that bind neurotrophins and the presence of these fragments in the circulation of patients who survive sepsis. This study highlights an important mechanism by which vascular injury can impair brain function.
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