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Piacentini R, Grassi C. Interleukin 1β receptor and synaptic dysfunction in recurrent brain infection with Herpes simplex virus type-1. Neural Regen Res 2025; 20:416-423. [PMID: 38819045 DOI: 10.4103/nrr.nrr-d-23-01690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 03/21/2024] [Indexed: 06/01/2024] Open
Abstract
Several experimental evidence suggests a link between brain Herpes simplex virus type-1 infection and the occurrence of Alzheimer's disease. However, the molecular mechanisms underlying this association are not completely understood. Among the molecular mediators of synaptic and cognitive dysfunction occurring after Herpes simplex virus type-1 infection and reactivation in the brain neuroinflammatory cytokines seem to occupy a central role. Here, we specifically reviewed literature reports dealing with the impact of neuroinflammation on synaptic dysfunction observed after recurrent Herpes simplex virus type-1 reactivation in the brain, highlighting the role of interleukins and, in particular, interleukin 1β as a possible target against Herpes simplex virus type-1-induced neuronal dysfunctions.
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Affiliation(s)
- Roberto Piacentini
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
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2
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Ma Y, Qiao Y, Gao X. Potential role of hippocampal neurogenesis in spinal cord injury induced post-trauma depression. Neural Regen Res 2024; 19:2144-2156. [PMID: 38488549 PMCID: PMC11034606 DOI: 10.4103/1673-5374.392855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 11/02/2023] [Accepted: 11/29/2023] [Indexed: 04/24/2024] Open
Abstract
It has been reported both in clinic and rodent models that beyond spinal cord injury directly induced symptoms, such as paralysis, neuropathic pain, bladder/bowel dysfunction, and loss of sexual function, there are a variety of secondary complications, including memory loss, cognitive decline, depression, and Alzheimer's disease. The large-scale longitudinal population-based studies indicate that post-trauma depression is highly prevalent in spinal cord injury patients. Yet, few basic studies have been conducted to address the potential molecular mechanisms. One of possible factors underlying the depression is the reduction of adult hippocampal neurogenesis which may come from less physical activity, social isolation, chronic pain, and elevated neuroinflammation after spinal cord injury. However, there is no clear consensus yet. In this review, we will first summarize the alteration of hippocampal neurogenesis post-spinal cord injury. Then, we will discuss possible mechanisms underlie this important spinal cord injury consequence. Finally, we will outline the potential therapeutic options aimed at enhancing hippocampal neurogenesis to ameliorate depression.
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Affiliation(s)
- Ying Ma
- Spinal Cord and Brain Injury Research Group, Stark Neuroscience Research Institute, Indianapolis, IN, USA
- Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Yue Qiao
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Xiang Gao
- Spinal Cord and Brain Injury Research Group, Stark Neuroscience Research Institute, Indianapolis, IN, USA
- Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
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3
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Qian H, Chen A, Lin D, Deng J, Gao F, Wei J, Wu X, Huang Y, Cai D, Chen X, Zheng X. Activation of the CD200/CD200R1 axis improves cognitive impairment by enhancing hippocampal neurogenesis via suppression of M1 microglial polarization and neuroinflammation in hypoxic-ischemic neonatal rats. Int Immunopharmacol 2024; 128:111532. [PMID: 38237226 DOI: 10.1016/j.intimp.2024.111532] [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: 08/31/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 02/08/2024]
Abstract
Following hypoxic-ischemic brain damage (HIBD), there is a decline in cognitive function; however, there are no effective treatment strategies for this condition in neonates. This study aimed to evaluate the role of the cluster of differentiation 200 (CD200)/CD200R1 axis in cognitive function following HIBD using an established model of HIBD in postnatal day 7 rats. Western blotting analysis was conducted to evaluate the protein expression levels of CD200, CD200R1, proteins associated with the PI3K/Akt-NF-κB pathway, and inflammatory factors such as TNF-α, IL-1β, and IL-6 in the hippocampus. Additionally, double-immunofluorescence labeling was utilized to evaluate M1 microglial polarization and neurogenesis in the hippocampus. To assess the learning and memory function of the experimental rats, the Morris water maze (MWM) test was conducted. HIBDleads to a decrease in the expression of CD200 and CD200R1 proteins in the neonatal rat hippocampus, while simultaneously increasing the expression of TNF-α, IL-6, and IL-1β proteins, ultimately resulting in cognitive impairment. The administration of CD200Fc, a fusion protein of CD200, was found to enhance the expression of p-PI3K and p-Akt, but reduce the expression of p-NF-κB. Additionally, CD200Fc inhibited M1 polarization of microglia, reduced neuroinflammation, improved hippocampal neurogenesis, and mitigated cognitive impairment caused by HIBD in neonatal rats. In contrast, blocking the interaction between CD200 and CD200R1 with the anti-CD200R1 antibody (CD200R1 Ab) exerted the opposite effect. Furthermore, the PI3K specific activator, 740Y-P, significantly increased the expression of p-PI3K and p-Akt, but reduced p-NF-κB expression. It also inhibited M1 polarization of microglia, reduced neuroinflammation, and improved hippocampal neurogenesis and cognitive function in neonatal rats with HIBD. Our findings illustrate that activation of the CD200/CD200R1 axis inhibits the NF-κB-mediated M1 polarization of microglia to improve HIBD-induced cognitive impairment and hippocampal neurogenesis disorder via the PI3K/Akt signaling pathway.
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Affiliation(s)
- Haitao Qian
- Shengli Clinical Medical College of Fujian Medical University, Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou, China
| | - Andi Chen
- Shengli Clinical Medical College of Fujian Medical University, Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou, China
| | - Daoyi Lin
- Shengli Clinical Medical College of Fujian Medical University, Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou, China
| | - Jianhui Deng
- Shengli Clinical Medical College of Fujian Medical University, Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou, China
| | - Fei Gao
- Shengli Clinical Medical College of Fujian Medical University, Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou, China
| | - Jianjie Wei
- Shengli Clinical Medical College of Fujian Medical University, Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou, China
| | - Xuyang Wu
- College of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Yongxin Huang
- Shengli Clinical Medical College of Fujian Medical University, Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou, China
| | - Dingliang Cai
- Shengli Clinical Medical College of Fujian Medical University, Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou, China
| | - Xiaohui Chen
- Shengli Clinical Medical College of Fujian Medical University, Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou, China.
| | - Xiaochun Zheng
- Shengli Clinical Medical College of Fujian Medical University, Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou, China; Fujian Emergency Medical Center, Fujian Provincial Key Laboratory of Critical Care Medicine, Fujian Provincial Co-Constructed Laboratory of "Belt and Road", Fuzhou, China.
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The Dialogue Between Neuroinflammation and Adult Neurogenesis: Mechanisms Involved and Alterations in Neurological Diseases. Mol Neurobiol 2023; 60:923-959. [PMID: 36383328 DOI: 10.1007/s12035-022-03102-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 10/23/2022] [Indexed: 11/18/2022]
Abstract
Adult neurogenesis occurs mainly in the subgranular zone of the hippocampal dentate gyrus and the subventricular zone of the lateral ventricles. Evidence supports the critical role of adult neurogenesis in various conditions, including cognitive dysfunction, Alzheimer's disease (AD), and Parkinson's disease (PD). Several factors can alter adult neurogenesis, including genetic, epigenetic, age, physical activity, diet, sleep status, sex hormones, and central nervous system (CNS) disorders, exerting either pro-neurogenic or anti-neurogenic effects. Compelling evidence suggests that any insult or injury to the CNS, such as traumatic brain injury (TBI), infectious diseases, or neurodegenerative disorders, can provoke an inflammatory response in the CNS. This inflammation could either promote or inhibit neurogenesis, depending on various factors, such as chronicity and severity of the inflammation and underlying neurological disorders. Notably, neuroinflammation, driven by different immune components such as activated glia, cytokines, chemokines, and reactive oxygen species, can regulate every step of adult neurogenesis, including cell proliferation, differentiation, migration, survival of newborn neurons, maturation, synaptogenesis, and neuritogenesis. Therefore, this review aims to present recent findings regarding the effects of various components of the immune system on adult neurogenesis and to provide a better understanding of the role of neuroinflammation and neurogenesis in the context of neurological disorders, including AD, PD, ischemic stroke (IS), seizure/epilepsy, TBI, sleep deprivation, cognitive impairment, and anxiety- and depressive-like behaviors. For each disorder, some of the most recent therapeutic candidates, such as curcumin, ginseng, astragaloside, boswellic acids, andrographolide, caffeine, royal jelly, estrogen, metformin, and minocycline, have been discussed based on the available preclinical and clinical evidence.
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Environmental Enrichment Protects Offspring of a Rat Model of Preeclampsia from Cognitive Decline. Cell Mol Neurobiol 2023; 43:381-394. [PMID: 35119541 DOI: 10.1007/s10571-022-01192-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 01/07/2022] [Indexed: 01/07/2023]
Abstract
Preeclampsia affects 5-7% of all pregnancies and contributes to adverse pregnancy and birth outcomes. In addition to the short-term effects of preeclampsia, preeclampsia can exert long-term adverse effects on offspring. Numerous studies have demonstrated that offspring of preeclamptic women exhibit cognitive deficits from childhood to old age. However, effective ways to improve the cognitive abilities of these offspring remain to be investigated. The aim of this study was to explore whether environmental enrichment in early life could restore the cognitive ability of the offspring of a rat model of preeclampsia and to investigate the cellular and molecular mechanisms by which EE improves cognitive ability. L-NAME was used to establish a rat model of preeclampsia. The spatial learning and memory abilities and recognition memory of 56-day-old offspring were evaluated by the Morris water maze and Novel object recognition (NOR) task. Immunofluorescence was performed to evaluate cell proliferation and apoptosis in the DG region of the hippocampus. qRT-PCR was performed to examine the expression levels of neurogenesis-associated genes, pre- and postsynaptic proteins and inflammatory cytokines. An enzyme-linked immune absorbent assay was performed to evaluate the concentration of vascular endothelial growth factor (VEGF) and inflammatory cytokines in the hippocampus. The administration of L-NAME led to increased systolic blood pressure and urine protein levels in pregnant rats. Offspring in the L-NAME group exhibited impaired spatial learning ability and memory as well as NOR memory. Hippocampal neurogenesis and synaptic plasticity were impaired in offspring from the L-NAME group. Furthermore, cell apoptosis in the hippocampus was increased in the L-NAME group. The hippocampus was skewed to a proinflammatory profile, as shown by increased inflammatory cytokine levels. EE improved the cognitive ability of offspring in the L-NAME group and resulted in increased hippocampal neurogenesis and synaptic protein expression levels and decreased apoptosis and inflammatory cytokine levels. Environmental enrichment resolves cognitive impairment in the offspring of a rat model of preeclampsia by improving hippocampal neurogenesis and synaptic plasticity and normalizing the apoptosis level and the inflammatory balance.
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Saikarthik J, Saraswathi I, Alarifi A, Al-Atram AA, Mickeymaray S, Paramasivam A, Shaikh S, Jeraud M, Alothaim AS. Role of neuroinflammation mediated potential alterations in adult neurogenesis as a factor for neuropsychiatric symptoms in Post-Acute COVID-19 syndrome-A narrative review. PeerJ 2022; 10:e14227. [PMID: 36353605 PMCID: PMC9639419 DOI: 10.7717/peerj.14227] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 09/22/2022] [Indexed: 11/06/2022] Open
Abstract
Persistence of symptoms beyond the initial 3 to 4 weeks after infection is defined as post-acute COVID-19 syndrome (PACS). A wide range of neuropsychiatric symptoms like anxiety, depression, post-traumatic stress disorder, sleep disorders and cognitive disturbances have been observed in PACS. The review was conducted based on PRISMA-S guidelines for literature search strategy for systematic reviews. A cytokine storm in COVID-19 may cause a breach in the blood brain barrier leading to cytokine and SARS-CoV-2 entry into the brain. This triggers an immune response in the brain by activating microglia, astrocytes, and other immune cells leading to neuroinflammation. Various inflammatory biomarkers like inflammatory cytokines, chemokines, acute phase proteins and adhesion molecules have been implicated in psychiatric disorders and play a major role in the precipitation of neuropsychiatric symptoms. Impaired adult neurogenesis has been linked with a variety of disorders like depression, anxiety, cognitive decline, and dementia. Persistence of neuroinflammation was observed in COVID-19 survivors 3 months after recovery. Chronic neuroinflammation alters adult neurogenesis with pro-inflammatory cytokines supressing anti-inflammatory cytokines and chemokines favouring adult neurogenesis. Based on the prevalence of neuropsychiatric symptoms/disorders in PACS, there is more possibility for a potential impairment in adult neurogenesis in COVID-19 survivors. This narrative review aims to discuss the various neuroinflammatory processes during PACS and its effect on adult neurogenesis.
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Affiliation(s)
- Jayakumar Saikarthik
- Department of Basic Medical Sciences, College of Dentistry, Al Zulfi, Majmaah University, Al-Majmaah, Riyadh, Kingdom of Saudi Arabia,Department of Medical Education, College of Dentistry, Al Zulfi, Majmaah University, Al Majmaah, Riyadh, Kingdom of Saudi Arabia
| | - Ilango Saraswathi
- Department of Physiology, Madha Medical College and Research Institute, Chennai, Tamil Nadu, India
| | - Abdulaziz Alarifi
- Department of Basic Sciences, College of Science and Health Professions, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia,King Abdullah International Medical Research Centre, Riyadh, Saudi Arabia
| | - Abdulrahman A. Al-Atram
- Department of Psychiatry, College of Medicine, Majmaah University, Al Majmaah, Riyadh, Kingdom of Saudi Arabia
| | - Suresh Mickeymaray
- Department of Biology, College of Science, Al Zulfi, Majmaah University, Al Majmaah, Riyadh, Kingdom of Saudi Arabia
| | - Anand Paramasivam
- Department of Physiology, RVS Dental College and Hospital, Kumaran Kottam Campus, Kannampalayan, Coimbatore, Tamilnadu, India
| | - Saleem Shaikh
- Department of Medical Education, College of Dentistry, Al Zulfi, Majmaah University, Al Majmaah, Riyadh, Kingdom of Saudi Arabia,Department of Maxillofacial Surgery and Diagnostic Sciences, College of Dentistry, Al Zulfi, Majmaah University, Al Majmaah, Riyadh, Kingdom of Saudi Arabia
| | - Mathew Jeraud
- Department of Physiology, Ibn Sina National College for Medical Studies, Jeddah, Saudi Arabia
| | - Abdulaziz S. Alothaim
- Department of Biology, College of Science, Al Zulfi, Majmaah University, Al Majmaah, Riyadh, Kingdom of Saudi Arabia
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McNerlin C, Guan F, Bronk L, Lei K, Grosshans D, Young DW, Gaber MW, Maletic-Savatic M. Targeting hippocampal neurogenesis to protect astronauts' cognition and mood from decline due to space radiation effects. LIFE SCIENCES IN SPACE RESEARCH 2022; 35:170-179. [PMID: 36336363 DOI: 10.1016/j.lssr.2022.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/30/2022] [Accepted: 07/26/2022] [Indexed: 06/16/2023]
Abstract
Neurogenesis is an essential, lifelong process during which neural stem cells generate new neurons within the hippocampus, a center for learning, memory, and mood control. Neural stem cells are vulnerable to environmental insults spanning from chronic stress to radiation. These insults reduce their numbers and diminish neurogenesis, leading to memory decline, anxiety, and depression. Preserving neural stem cells could thus help prevent these neurogenesis-associated pathologies, an outcome particularly important for long-term space missions where environmental exposure to radiation is significantly higher than on Earth. Multiple developments, from mechanistic discoveries of radiation injury on hippocampal neurogenesis to new platforms for the development of selective, specific, effective, and safe small molecules as neurogenesis-protective agents hold great promise to minimize radiation damage on neurogenesis. In this review, we summarize the effects of space-like radiation on hippocampal neurogenesis. We then focus on current advances in drug discovery and development and discuss the nuclear receptor TLX/NR2E1 (oleic acid receptor) as an example of a neurogenic target that might rescue neurogenesis following radiation.
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Affiliation(s)
- Clare McNerlin
- Georgetown University School of Medicine, 3900 Reservoir Rd NW, Washington D.C. 20007, United States of America
| | - Fada Guan
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, 06510, United States of America
| | - Lawrence Bronk
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, United States of America
| | - Kevin Lei
- Graduate School for Biomedical Sciences, Baylor College of Medicine, Houston, Texas, 77030, United States of America; Jan and Dan Duncan Neurological Research Institute, 1250 Moursund St. Houston, TX 77030, United States of America
| | - David Grosshans
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, United States of America
| | - Damian W Young
- Jan and Dan Duncan Neurological Research Institute, 1250 Moursund St. Houston, TX 77030, United States of America; Center for Drug Discovery, Department of Pathology and Immunology Baylor College of Medicine, Houston, Texas, 77030, United States of America; Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas 77030, United States of America
| | - M Waleed Gaber
- Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, United States of America.
| | - Mirjana Maletic-Savatic
- Jan and Dan Duncan Neurological Research Institute, 1250 Moursund St. Houston, TX 77030, United States of America; Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, United States of America; Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, United States of America.
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Neuroprotective Effect of Bcl-2 on Lipopolysaccharide-Induced Neuroinflammation in Cortical Neural Stem Cells. Int J Mol Sci 2022; 23:ijms23126399. [PMID: 35742844 PMCID: PMC9223771 DOI: 10.3390/ijms23126399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 11/17/2022] Open
Abstract
Neuroinflammation is involved in the pathogenesis of neurodegenerative diseases due to increased levels of pro-inflammatory cytokines in the central nervous system (CNS). Chronic neuroinflammation induced by neurotoxic molecules accelerates neuronal damage. B-cell lymphoma 2 (Bcl-2) is generally accepted to be an important anti-apoptotic factor. However, the role of Bcl-2 in neuroprotection against neuroinflammation remains to be determined. The purpose of this study was to investigate the neuroprotective effect of Bcl-2 on lipopolysaccharide (LPS)-induced neuroinflammation in cortical neural stem cells (NSCs). LPS decreased mRNA and protein levels of Tuj-1, a neuron marker, and also suppressed neurite outgrowth, indicating that LPS results in inhibition of neuronal differentiation of NSCs. Furthermore, LPS treatment inhibited Bcl-2 expression during neuronal differentiation; inhibition of neuronal differentiation by LPS was rescued by Bcl-2 overexpression. LPS-induced pro-inflammatory cytokines, including interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α), were decreased by Bcl-2 overexpression. Conversely, Bcl-2 siRNA increased the LPS-induced levels of IL-6 and TNF-α, and decreased neuronal differentiation of NSCs, raising the possibility that Bcl-2 mediates neuronal differentiation by inhibiting the LPS-induced inflammatory response in NSC. These results suggest that Bcl-2 has a neuroprotective effect by inhibiting the LPS-induced inflammatory response in NSCs.
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Chronic IL-10 overproduction disrupts microglia-neuron dialogue similar to aging, resulting in impaired hippocampal neurogenesis and spatial memory. Brain Behav Immun 2022; 101:231-245. [PMID: 34990747 DOI: 10.1016/j.bbi.2021.12.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 12/24/2021] [Accepted: 12/29/2021] [Indexed: 11/21/2022] Open
Abstract
The subgranular zone of the dentate gyrus is an adult neurogenic niche where new neurons are continuously generated. A dramatic hippocampal neurogenesis decline occurs with increasing age, contributing to cognitive deficits. The process of neurogenesis is intimately regulated by the microenvironment, with inflammation being considered a strong negative factor for this process. Thus, we hypothesize that the reduction of new neurons in the aged brain could be attributed to the age-related microenvironmental changes towards a pro-inflammatory status. In this work, we evaluated whether an anti-inflammatory microenvironment could counteract the negative effect of age on promoting new hippocampal neurons. Surprisingly, our results show that transgenic animals chronically overexpressing IL-10 by astrocytes present a decreased hippocampal neurogenesis in adulthood. This results from an impairment in the survival of neural newborn cells without differences in cell proliferation. In parallel, hippocampal-dependent spatial learning and memory processes were affected by IL-10 overproduction as assessed by the Morris water maze test. Microglial cells, which are key players in the neurogenesis process, presented a different phenotype in transgenic animals characterized by high activation together with alterations in receptors involved in neuronal communication, such as CD200R and CX3CR1. Interestingly, the changes described in adult transgenic animals were similar to those observed by the effect of normal aging. Thus, our data suggest that chronic IL-10 overproduction mimics the physiological age-related disruption of the microglia-neuron dialogue, resulting in hippocampal neurogenesis decrease and spatial memory impairment.
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Ma Y, Yang S, He Q, Zhang D, Chang J. The Role of Immune Cells in Post-Stroke Angiogenesis and Neuronal Remodeling: The Known and the Unknown. Front Immunol 2022; 12:784098. [PMID: 34975872 PMCID: PMC8716409 DOI: 10.3389/fimmu.2021.784098] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 11/29/2021] [Indexed: 12/12/2022] Open
Abstract
Following a cerebral ischemic event, substantial alterations in both cellular and molecular activities occur due to ischemia-induced cerebral pathology. Mounting evidence indicates that the robust recruitment of immune cells plays a central role in the acute stage of stroke. Infiltrating peripheral immune cells and resident microglia mediate neuronal cell death and blood-brain barrier disruption by releasing inflammation-associated molecules. Nevertheless, profound immunological effects in the context of the subacute and chronic recovery phase of stroke have received little attention. Early attempts to curtail the infiltration of immune cells were effective in mitigating brain injury in experimental stroke studies but failed to exert beneficial effects in clinical trials. Neural tissue damage repair processes include angiogenesis, neurogenesis, and synaptic remodeling, etc. Post-stroke inflammatory cells can adopt divergent phenotypes that influence the aforementioned biological processes in both endothelial and neural stem cells by either alleviating acute inflammatory responses or secreting a variety of growth factors, which are substantially involved in the process of angiogenesis and neurogenesis. To better understand the multiple roles of immune cells in neural tissue repair processes post stroke, we review what is known and unknown regarding the role of immune cells in angiogenesis, neurogenesis, and neuronal remodeling. A comprehensive understanding of these inflammatory mechanisms may help identify potential targets for the development of novel immunoregulatory therapeutic strategies that ameliorate complications and improve functional rehabilitation after stroke.
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Affiliation(s)
- Yinzhong Ma
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Shilun Yang
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Qianyan He
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Dianhui Zhang
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Junlei Chang
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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IL-1 reprogramming of adult neural stem cells limits neurocognitive recovery after viral encephalitis by maintaining a proinflammatory state. Brain Behav Immun 2022; 99:383-396. [PMID: 34695572 DOI: 10.1016/j.bbi.2021.10.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 02/07/2023] Open
Abstract
Innate immune responses to emerging RNA viruses are increasingly recognized as having significant contributions to neurologic sequelae, especially memory disorders. Using a recovery model of West Nile virus (WNV) encephalitis, we show that, while macrophages deliver the antiviral and anti-neurogenic cytokine IL-1β during acute infection; viral recovery is associated with continued astrocyte inflammasome-mediated production of inflammatory levels of IL-1β, which is maintained by hippocampal astrogenesis via IL-1R1 signaling in neural stem cells (NSC). Accordingly, aberrant astrogenesis is prevented in the absence of IL-1 signaling in NSC, indicating that only newly generated astrocytes exert neurotoxic effects, preventing synapse repair and promoting spatial learning deficits. Ex vivo evaluation of IL-1β-treated adult hippocampal NSC revealed the upregulation of developmental differentiation pathways that derail adult neurogenesis in favor of astrogenesis, following viral infection. We conclude that NSC-specific IL-1 signaling within the hippocampus during viral encephalitis prevents synapse recovery and promotes spatial learning defects via altered fates of NSC progeny that maintain inflammation.
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12
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Han KM, Ham BJ. How Inflammation Affects the Brain in Depression: A Review of Functional and Structural MRI Studies. J Clin Neurol 2021; 17:503-515. [PMID: 34595858 PMCID: PMC8490908 DOI: 10.3988/jcn.2021.17.4.503] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 08/30/2021] [Accepted: 08/30/2021] [Indexed: 12/27/2022] Open
Abstract
This narrative review discusses how peripheral and central inflammation processes affect brain function and structure in depression, and reports on recent peripheral inflammatory marker-based functional and structural magnetic resonance imaging (MRI) studies from the perspective of neural-circuit dysfunction in depression. Chronic stress stimulates the activity of microglial cells, which increases the production of pro-inflammatory cytokines in the brain. In addition, microglial activation promotes a shift from the synthesis of serotonin to the synthesis of neurotoxic metabolites of the kynurenine pathway, which induces glutamate-mediated excitotoxicity in neurons. Furthermore, the region specificity of microglial activation is hypothesized to contribute to the vulnerability of specific brain regions in the depression-related neural circuits to inflammation-mediated brain injury. MRI studies are increasingly investigating how the blood levels of inflammatory markers such as C-reactive protein, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α are associated with functional and structural neuroimaging markers in depression. Functional MRI studies have found that peripheral inflammatory markers are associated with aberrant activation patterns and altered functional connectivity in neural circuits involved in emotion regulation, reward processing, and cognitive control in depression. Structural MRI studies have suggested that peripheral inflammatory markers are related to reduced cortical gray matter and subcortical volumes, cortical thinning, and decreased integrity of white matter tracts within depression-related neural circuits. These neuroimaging findings may improve our understanding of the relationships between neuroinflammatory processes at the molecular level and macroscale in vivo neuralcircuit dysfunction in depression.
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Affiliation(s)
- Kyu Man Han
- Department of Psychiatry, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea
| | - Byung Joo Ham
- Department of Psychiatry, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea.
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Parkitny L, Maletic-Savatic M. Glial PAMPering and DAMPening of Adult Hippocampal Neurogenesis. Brain Sci 2021; 11:1299. [PMID: 34679362 PMCID: PMC8533961 DOI: 10.3390/brainsci11101299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 09/16/2021] [Accepted: 09/22/2021] [Indexed: 12/24/2022] Open
Abstract
Adult neurogenesis represents a mature brain's capacity to integrate newly generated neurons into functional circuits. Impairment of neurogenesis contributes to the pathophysiology of various mood and cognitive disorders such as depression and Alzheimer's Disease. The hippocampal neurogenic niche hosts neural progenitors, glia, and vasculature, which all respond to intrinsic and environmental cues, helping determine their current state and ultimate fate. In this article we focus on the major immune communication pathways and mechanisms through which glial cells sense, interact with, and modulate the neurogenic niche. We pay particular attention to those related to the sensing of and response to innate immune danger signals. Receptors for danger signals were first discovered as a critical component of the innate immune system response to pathogens but are now also recognized to play a crucial role in modulating non-pathogenic sterile inflammation. In the neurogenic niche, viable, stressed, apoptotic, and dying cells can activate danger responses in neuroimmune cells, resulting in neuroprotection or neurotoxicity. Through these mechanisms glial cells can influence hippocampal stem cell fate, survival, neuronal maturation, and integration. Depending on the context, such responses may be appropriate and on-target, as in the case of learning-associated synaptic pruning, or excessive and off-target, as in neurodegenerative disorders.
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Affiliation(s)
- Luke Parkitny
- Baylor College of Medicine and Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA;
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14
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Abstract
Interleukin-1 (IL-1) is an inflammatory cytokine that has been shown to modulate neuronal signaling in homeostasis and diseases. In homeostasis, IL-1 regulates sleep and memory formation, whereas in diseases, IL-1 impairs memory and alters affect. Interestingly, IL-1 can cause long-lasting changes in behavior, suggesting IL-1 can alter neuroplasticity. The neuroplastic effects of IL-1 are mediated via its cognate receptor, Interleukin-1 Type 1 Receptor (IL-1R1), and are dependent on the distribution and cell type(s) of IL-1R1 expression. Recent reports found that IL-1R1 expression is restricted to discrete subpopulations of neurons, astrocytes, and endothelial cells and suggest IL-1 can influence neural circuits directly through neuronal IL-1R1 or indirectly via non-neuronal IL-1R1. In this review, we analyzed multiple mechanisms by which IL-1/IL-1R1 signaling might impact neuroplasticity based upon the most up-to-date literature and provided potential explanations to clarify discrepant and confusing findings reported in the past.
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Affiliation(s)
- Daniel P. Nemeth
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
- Department of Biomedical Science, Charles E. Schmidt College of Medicine and Brain Institute, Florida Atlantic University, Jupiter, FL, USA
| | - Ning Quan
- Department of Biomedical Science, Charles E. Schmidt College of Medicine and Brain Institute, Florida Atlantic University, Jupiter, FL, USA
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15
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Asl SS, Jalili C, Artimani T, Ramezani M, Mirzaei F. Inflammasome can Affect Adult Neurogenesis: A Review Article. Open Neurol J 2021. [DOI: 10.2174/1874205x02115010025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adult neurogenesis is the process of producing new neurons in the adult brain and is limited to two major areas: the hippocampal dentate gyrus and the Subventricular Zone (SVZ). Adult neurogenesis is affected by some physiological, pharmacological, and pathological factors. The inflammasome is a major signalling platform that regulates caspase-1 and induces proinflammatory cytokines production such as interleukin-1β (IL1-β) and IL-18.
Inflammasomes may be stimulated through multiple signals, and some of these signaling factors can affect neurogenesis. In the current review, “adult neurogenesis and inflammasome” were searched in PubMed, Scopus, and Google Scholar. Reviewing various research works showed correlations between inflammasome and neurogenesis by different intermediate factors, such as interferons (IFN), interleukins (IL), α-synuclein, microRNAs, and natural compounds. Concerning the significant role of neurogenesis in the health of the nervous system and memory, understanding factors inducing neurogenesis is crucial for identifying new therapeutic aims. Hence in this review, we will discuss the different mechanisms by which inflammasome influences adult neurogenesis.
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16
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Sefiani A, Geoffroy CG. The Potential Role of Inflammation in Modulating Endogenous Hippocampal Neurogenesis After Spinal Cord Injury. Front Neurosci 2021; 15:682259. [PMID: 34220440 PMCID: PMC8249862 DOI: 10.3389/fnins.2021.682259] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/17/2021] [Indexed: 12/24/2022] Open
Abstract
Currently there are approximately 291,000 people suffering from a spinal cord injury (SCI) in the United States. SCI is associated with traumatic changes in mobility and neuralgia, as well as many other long-term chronic health complications, including metabolic disorders, diabetes mellitus, non-alcoholic steatohepatitis, osteoporosis, and elevated inflammatory markers. Due to medical advances, patients with SCI survive much longer than previously. This increase in life expectancy exposes them to novel neurological complications such as memory loss, cognitive decline, depression, and Alzheimer's disease. In fact, these usually age-associated disorders are more prevalent in people living with SCI. A common factor of these disorders is the reduction in hippocampal neurogenesis. Inflammation, which is elevated after SCI, plays a major role in modulating hippocampal neurogenesis. While there is no clear consensus on the mechanism of the decline in hippocampal neurogenesis and cognition after SCI, we will examine in this review how SCI-induced inflammation could modulate hippocampal neurogenesis and provoke age-associated neurological disorders. Thereafter, we will discuss possible therapeutic options which may mitigate the influence of SCI associated complications on hippocampal neurogenesis.
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17
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Exercise alters LPS-induced glial activation in the mouse brain. Neuronal Signal 2020; 4:NS20200003. [PMID: 33304620 PMCID: PMC7711064 DOI: 10.1042/ns20200003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 10/23/2020] [Accepted: 11/05/2020] [Indexed: 12/11/2022] Open
Abstract
Experimental and epidemiological evidence suggest that modifiable lifestyle factors, including physical exercise, can build structural and cognitive reserve in the brain, increasing resilience to injury and insult. Accordingly, exercise can reduce the increased expression of proinflammatory cytokines in the brain associated with ageing or experimentally induced neuroinflammation. However, the cellular mechanisms by which exercise exerts this effect are unknown, including the effects of exercise on classic or alternative activation of astrocytes and microglia. In the present study, we assess the effects of nine consecutive days of treadmill running on the glial cell response to a single systemic injection of lipopolysaccharide (LPS) and, in parallel, the effects on spatial learning and memory. We show that prior exercise protects against LPS-induced impairment of performance in the object displacement task concomitant with attenuation of IL-1β, TNFα and IL-10 mRNA expression in the hippocampus. Assessment of isolated astrocytes and microglia revealed that LPS induced a proinflammatory response in these cells that was not observed in cells prepared from the brains of mice who had undergone prior exercise. The results suggest that exercise modulates neuroinflammation by reducing the proinflammatory microglial response, suggesting a mechanism by which exercise may be neuroprotective.
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18
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Wang P, Liang Y, Chen K, Yau SY, Sun X, Cheng KKY, Xu A, So KF, Li A. Potential Involvement of Adiponectin Signaling in Regulating Physical Exercise-Elicited Hippocampal Neurogenesis and Dendritic Morphology in Stressed Mice. Front Cell Neurosci 2020; 14:189. [PMID: 32774242 PMCID: PMC7381385 DOI: 10.3389/fncel.2020.00189] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 05/29/2020] [Indexed: 12/12/2022] Open
Abstract
Adiponectin, a cytokine secreted by mature adipocytes, proves to be neuroprotective. We have previously reported that running triggers adiponectin up-regulation which subsequently promotes generation of hippocampal neurons and thereby alleviates depression-like behaviors in non-stressed mice. However, under the stressing condition, whether adiponectin could still exert antidepressant-like effects following exercise remained unexplored. In this study, by means of repeated corticosterone injections to mimic stress insult and voluntary wheel running as physical exercise intervention, we examined whether exercise-elicited antidepressive effects might involve adiponectin's regulation on hippocampal neurogenesis and dendritic plasticity in stressed mice. Here we show that repeated injections of corticosterone inhibited hippocampal neurogenesis and impaired dendritic morphology of neurons in the dentate gyrus of both wild-type and adiponectin-knockout mice comparably, which subsequently evoked depression-like behaviors. Voluntary wheel running attenuated corticosterone-suppressed neurogenesis and enhanced dendritic plasticity in the hippocampus, ultimately reducing depression-like behaviors in wild-type, but not adiponectin-knockout mice. We further demonstrate that such proneurogenic effects were potentially achieved through activation of the AMP-dependent kinase (AMPK) pathway. Our study provides the first evidence that adiponectin signaling is essential for physical exercise-triggered effects on stress-elicited depression by retaining the normal proliferation of neural progenitors and dendritic morphology of neurons in the hippocampal dentate gyrus, which may depend on activation of the AMPK pathway.
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Affiliation(s)
- Pingjie Wang
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Joint International Research Laboratory of CNS Regeneration Ministry of Education, Jinan University, Guangzhou, China
| | - Yiyao Liang
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Joint International Research Laboratory of CNS Regeneration Ministry of Education, Jinan University, Guangzhou, China
| | - Kai Chen
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Joint International Research Laboratory of CNS Regeneration Ministry of Education, Jinan University, Guangzhou, China
| | - Suk-Yu Yau
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Xin Sun
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Joint International Research Laboratory of CNS Regeneration Ministry of Education, Jinan University, Guangzhou, China
| | - Kenneth King-Yip Cheng
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Aimin Xu
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong.,Department of Pharmacy and Pharmacology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong.,State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Pokfulam, Hong Kong
| | - Kwok-Fai So
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Joint International Research Laboratory of CNS Regeneration Ministry of Education, Jinan University, Guangzhou, China.,State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong.,Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Ang Li
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Joint International Research Laboratory of CNS Regeneration Ministry of Education, Jinan University, Guangzhou, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
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19
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Troubat R, Barone P, Leman S, Desmidt T, Cressant A, Atanasova B, Brizard B, El Hage W, Surget A, Belzung C, Camus V. Neuroinflammation and depression: A review. Eur J Neurosci 2020; 53:151-171. [DOI: 10.1111/ejn.14720] [Citation(s) in RCA: 225] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 02/20/2020] [Accepted: 03/03/2020] [Indexed: 02/06/2023]
Affiliation(s)
| | - Pascal Barone
- UMR 1253 iBrain Université de Tours Inserm Tours France
| | - Samuel Leman
- UMR 1253 iBrain Université de Tours Inserm Tours France
| | - Thomas Desmidt
- UMR 1253 iBrain Université de Tours Inserm Tours France
- CHRU de Tours Tours France
| | | | | | - Bruno Brizard
- UMR 1253 iBrain Université de Tours Inserm Tours France
| | - Wissam El Hage
- UMR 1253 iBrain Université de Tours Inserm Tours France
- CHRU de Tours Tours France
| | | | | | - Vincent Camus
- UMR 1253 iBrain Université de Tours Inserm Tours France
- CHRU de Tours Tours France
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20
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Pawley LC, Hueston CM, O'Leary JD, Kozareva DA, Cryan JF, O'Leary OF, Nolan YM. Chronic intrahippocampal interleukin-1β overexpression in adolescence impairs hippocampal neurogenesis but not neurogenesis-associated cognition. Brain Behav Immun 2020; 83:172-179. [PMID: 31604142 DOI: 10.1016/j.bbi.2019.10.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/02/2019] [Accepted: 10/05/2019] [Indexed: 02/06/2023] Open
Abstract
Both neuroinflammation and adult hippocampal neurogenesis (AHN) are implicated in many neurodegenerative disorders as well as in neuropsychiatric disorders, which often become symptomatic during adolescence. A better knowledge of the impact that chronic neuroinflammation has on the hippocampus during the adolescent period could lead to the discovery of new therapeutics for some of these disorders. The hippocampus is particularly vulnerable to altered concentrations of the pro-inflammatory cytokine interleukin-1β (IL-1β), with elevated levels implicated in the aetiology of neurodegenerative disorders such as Alzheimer's and Parkinson's, and stress-related disorders such as depression. The effect of acutely and chronically elevated concentrations of hippocampal IL-1β have been shown to reduce AHN in adult rodents. However, the effect of exposure to chronic overexpression of hippocampal IL-1β during adolescence, a time of increased vulnerability, hasn't been fully interrogated. Thus, in this study we utilized a lentiviral approach to induce chronic overexpression of IL-1β in the dorsal hippocampus of adolescent male Sprague Dawley rats for 5 weeks, during which time its impact on cognition and hippocampal neurogenesis were examined. A reduction in hippocampal neurogenesis was observed along with a reduced level of neurite branching on hippocampal neurons. However, there was no effect of IL-1β overexpression on performance in pattern separation, novel object recognition or spontaneous alternation in the Y maze. Our study has highlighted that chronic IL-1β overexpression in the hippocampus during the adolescent period exerts a negative impact on neurogenesis independent of cognitive performance, and suggests a degree of resilience of the adolescent hippocampus to inflammatory insult.
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Affiliation(s)
- Lauren C Pawley
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Cara M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - James D O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Danka A Kozareva
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - Olivia F O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland.
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21
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Xiong Q, Wu Y, Yang M, Wu G, Wang Y, Wang H, Feng J, Song L, Tong B, He G, Xu Y. Nr2e1 ablation impairs liver glucolipid metabolism and induces inflammation, high-fat diets amplify the damage. Biomed Pharmacother 2019; 120:109503. [DOI: 10.1016/j.biopha.2019.109503] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 09/17/2019] [Accepted: 09/26/2019] [Indexed: 02/08/2023] Open
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22
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Cruz-Pereira JS, Rea K, Nolan YM, O'Leary OF, Dinan TG, Cryan JF. Depression's Unholy Trinity: Dysregulated Stress, Immunity, and the Microbiome. Annu Rev Psychol 2019; 71:49-78. [PMID: 31567042 DOI: 10.1146/annurev-psych-122216-011613] [Citation(s) in RCA: 146] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Depression remains one of the most prevalent psychiatric disorders, with many patients not responding adequately to available treatments. Chronic or early-life stress is one of the key risk factors for depression. In addition, a growing body of data implicates chronic inflammation as a major player in depression pathogenesis. More recently, the gut microbiota has emerged as an important regulator of brain and behavior and also has been linked to depression. However, how this holy trinity of risk factors interact to maintain physiological homeostasis in the brain and body is not fully understood. In this review, we integrate the available data from animal and human studies on these three factors in the etiology and progression of depression. We also focus on the processes by which this microbiota-immune-stress matrix may influence centrally mediated events and on possible therapeutic interventions to correct imbalances in this triune.
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Affiliation(s)
- Joana S Cruz-Pereira
- APC Microbiome Ireland, University College Cork, Cork T12 K8AF, Ireland; , , , , , .,Department of Anatomy and Neuroscience, University College Cork, Cork T12 K8AF, Ireland
| | - Kieran Rea
- APC Microbiome Ireland, University College Cork, Cork T12 K8AF, Ireland; , , , , ,
| | - Yvonne M Nolan
- APC Microbiome Ireland, University College Cork, Cork T12 K8AF, Ireland; , , , , , .,Department of Anatomy and Neuroscience, University College Cork, Cork T12 K8AF, Ireland
| | - Olivia F O'Leary
- APC Microbiome Ireland, University College Cork, Cork T12 K8AF, Ireland; , , , , , .,Department of Anatomy and Neuroscience, University College Cork, Cork T12 K8AF, Ireland
| | - Timothy G Dinan
- APC Microbiome Ireland, University College Cork, Cork T12 K8AF, Ireland; , , , , , .,Department of Psychiatry and Neurobehavioral Science, University College Cork, Cork T12 K8AF, Ireland
| | - John F Cryan
- APC Microbiome Ireland, University College Cork, Cork T12 K8AF, Ireland; , , , , , .,Department of Anatomy and Neuroscience, University College Cork, Cork T12 K8AF, Ireland
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23
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The orphan nuclear receptor TLX: an emerging master regulator of cross-talk between microglia and neural precursor cells. Neuronal Signal 2019; 3:NS20180208. [PMID: 32271856 PMCID: PMC7104320 DOI: 10.1042/ns20180208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/11/2019] [Accepted: 05/13/2019] [Indexed: 12/12/2022] Open
Abstract
Neuroinflammation and neurogenesis have both been the subject of intensive investigation over the past 20 years. The sheer complexity of their regulation and their ubiquity in various states of health and disease have sometimes obscured the progress that has been made in unraveling their mechanisms and regulation. A recent study by Kozareva et al. (Neuronal Signaling (2019) 3), provides evidence that the orphan nuclear receptor TLX is central to communication between microglia and neural precursor cells and could help us understand how inflammation, mediated by microglia, influences the development of new neurons in the adult hippocampus. Here, we put recent studies on TLX into the context of what is known about adult neurogenesis and microglial activation in the brain, along with the many hints that these processes must be inter-related.
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Hill JD, Zuluaga-Ramirez V, Gajghate S, Winfield M, Sriram U, Persidsky Y, Persidsky Y. Activation of GPR55 induces neuroprotection of hippocampal neurogenesis and immune responses of neural stem cells following chronic, systemic inflammation. Brain Behav Immun 2019; 76:165-181. [PMID: 30465881 PMCID: PMC6398994 DOI: 10.1016/j.bbi.2018.11.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 11/13/2018] [Accepted: 11/18/2018] [Indexed: 12/12/2022] Open
Abstract
New neurons are continuously produced by neural stem cells (NSCs) within the adult hippocampus. Numerous diseases, including major depressive disorder and HIV-1 associated neurocognitive disorder, are associated with decreased rates of adult neurogenesis. A hallmark of these conditions is a chronic release of neuroinflammatory mediators by activated resident glia. Recent studies have shown a neuroprotective role on NSCs of cannabinoid receptor activation. Yet, little is known about the effects of GPR55, a candidate cannabinoid receptor, activation on reductions of neurogenesis in response to inflammatory insult. In the present study, we examined NSCs exposed to IL-1β in vitro to assess inflammation-caused effects on NSC differentiation and the ability of GPR55 agonists to attenuate NSC injury. NSC differentiation and neurogenesis was determined via immunofluorescence and flow cytometric analysis of NSC markers (Nestin, Sox2, DCX, S100β, βIII Tubulin, GFAP). GPR55 agonist treatment protected against IL-1β induced reductions in neurogenesis rates. Moreover, inflammatory cytokine receptor mRNA expression was down regulated by GPR55 activation in a neuroprotective manner. To determine inflammatory responses in vivo, we treated C57BL/6 and GPR55-/- mice with LPS (0.2 mg/kg/day) continuously for 14 days via osmotic mini-pump. Reductions in NSC survival (as determined by BrdU incorporation), immature neurons, and neuroblast formation due to LPS were attenuated by concurrent direct intrahippocampal administration of the GPR55 agonist, O-1602 (4 µg/kg/day). Molecular analysis of the hippocampal region showed a suppressed ability to regulate immune responses by GPR55-/- animals manifesting in a prolonged inflammatory response (IL-1β, IL-6, TNFα) after chronic, systemic inflammation as compared to C57BL/6 animals. Taken together, these results suggest a neuroprotective role of GPR55 activation on NSCs in vitro and in vivo and that GPR55 provides a novel therapeutic target against negative regulation of hippocampal neurogenesis by inflammatory insult.
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Affiliation(s)
- Jeremy D. Hill
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA,Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Viviana Zuluaga-Ramirez
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Sachin Gajghate
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Malika Winfield
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Uma Sriram
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Yuri Persidsky
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA; Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA.
| | - Yuri Persidsky
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA; Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA.
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25
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Zuo Y, Wang J, Enkhjargal B, Doycheva D, Yan X, Zhang JH, Liu F. Neurogenesis changes and the fate of progenitor cells after subarachnoid hemorrhage in rats. Exp Neurol 2019; 311:274-284. [PMID: 30359565 DOI: 10.1016/j.expneurol.2018.10.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 10/16/2018] [Accepted: 10/20/2018] [Indexed: 11/27/2022]
Abstract
BACKGROUND Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular disease that leads to poor outcomes. Neurogenesis, an essential recovery mechanism after brain injury, has not been fully elucidated after SAH. METHODS A total of 122 SD rats were used in this study. For experiment one, the rats were randomly divided into six groups: sham and SAH with different time points (1,3,5,7,14 days) (n = 12/group). An endovascular perforation method was conducted for SAH model. Rats were injected with 5-Bromo-2'-deoxyuridine (BrdU, 50 mg/kg) 24 h before euthanasia at different time points after SAH. The BrdU labeled cells were detected by immunohistochemistry; Doublecortin (DCX) and glial fibrillary acidic protein (GFAP) were measured by western blot and immunohistochemistry. For experiment two, rats were randomly divided into five groups: sham and SAH with different time points (1, 2, 4, 8 weeks) (n = 6/group). Rats received BrdU (50 mg/kg) once daily for 7 days after the induction of SAH. Double immunofluorescence staining was used to verify proliferation, differentiation and migration of progenitor cells. Rotarod test and water maze used to test the neurobehavioral recovery. RESULTS Our results showed that BrdU positive cells in hippocampus changed overtime after SAH. BrdU positive cells decreased as early as 1 day reaching lowest levels at 3 days after SAH, after which it gradually recovered. Similar change patterns were observed with DCX, which was reversed with GFAP. In addition, BrdU did not co-localize with cleaved caspase-3. The BrdU positive cells mainly differentiated into immature neurons for short-term fate, whereas they differentiated into mature neurons for long-term fate but not astrocytes, which facilitated neurobehavioral recovery after SAH. CONCLUSION Neurogenesis in the hippocampus changes overtime after SAH. The neuronal progenitor cells may play an essential role in the neurobehavioral recovery after brain injury induced by SAH, since short-term progenitors helped with the recovery of immature neurons in the hippocampus, whereas long-term progenitors differentiated into mature neurons.
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Affiliation(s)
- Yuchun Zuo
- Department of Neurosurgery, The third XiangYa Hospital, Central South University, Changsha 410013, China
| | - Jikai Wang
- Department of Neurosurgery, The third XiangYa Hospital, Central South University, Changsha 410013, China
| | - Budbazar Enkhjargal
- Department of Physiology and Pharmacology, Loma Linda University, CA 92354, USA
| | - Desislava Doycheva
- Department of Physiology and Pharmacology, Loma Linda University, CA 92354, USA
| | - Xiaoxin Yan
- Department of Anatomy, XiangYa Medical School, Central South University, Changsha 410013, China
| | - John H Zhang
- Department of Physiology and Pharmacology, Loma Linda University, CA 92354, USA.
| | - Fei Liu
- Department of Neurosurgery, The third XiangYa Hospital, Central South University, Changsha 410013, China.
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26
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Zuo Y, Wang J, Liao F, Yan X, Li J, Huang L, Liu F. Inhibition of Heat Shock Protein 90 by 17-AAG Reduces Inflammation via P2X7 Receptor/NLRP3 Inflammasome Pathway and Increases Neurogenesis After Subarachnoid Hemorrhage in Mice. Front Mol Neurosci 2018; 11:401. [PMID: 30459553 PMCID: PMC6232389 DOI: 10.3389/fnmol.2018.00401] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/12/2018] [Indexed: 12/23/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) is a life-threatening cerebrovascular disease that usually has a poor prognosis. Heat shock proteins (HSPs) have been implicated in the mechanisms of SAH-associated damage, including increased inflammation and reduced neurogenesis. The aim of this study was to investigate the effects of HSP90 inhibition on inflammation and neurogenesis in a mouse model of experimental SAH induced by endovascular surgery. Western blotting showed HSP90 levels to be decreased, while neurogenesis, evaluated by 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry, was decreased in the hippocampuses of SAH mice. SAH also induced pro-inflammatory factors such as interleukin-1β (IL-1β), capase-1 and the NLRP3 inflammasome. However, intraperitoneal administration of the specific HSP90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) reduced the levels of HSP90, NLRP3, ASC, caspase-1 and IL-1β, while increasing the levels of brain-derived neurotrophic factor and doublecortin (DCX), as well as the number of BrdU-positive cells in SAH mice. In addition, 17-AGG improved short- and long-term neurobehavioral outcomes. The neuroprotective and anti-inflammatory effects of 17-AGG were reversed by recombinant HSP90 (rHSP90); this detrimental effect of HSP90 was inhibited by the specific P2X7 receptor (P2X7R) inhibitor A438079, indicating that SAH-induced inflammation and inhibition of neurogenesis were likely mediated by HSP90 and the P2X7R/NLRP3 inflammasome pathway. HSP90 inhibition by 17-AAG may be a promising therapeutic strategy for the treatment of SAH.
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Affiliation(s)
- Yuchun Zuo
- Department of Neurosurgery, Third XiangYa Hospital, Central South University, Changsha, China
| | - Jikai Wang
- Department of Neurosurgery, Third XiangYa Hospital, Central South University, Changsha, China
| | - Fan Liao
- Department of Neurosurgery, Third XiangYa Hospital, Central South University, Changsha, China
| | - Xiaoxin Yan
- Department of Anatomy, XiangYa Medical School, Central South University, Changsha, China
| | - Jianming Li
- Neuroscience Research Center, Changsha Medical University, Changsha, China
| | - Lei Huang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, United States.,Department of Neurosurgery, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Fei Liu
- Department of Neurosurgery, Third XiangYa Hospital, Central South University, Changsha, China
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Hueston CM, O'Leary JD, Hoban AE, Kozareva DA, Pawley LC, O'Leary OF, Cryan JF, Nolan YM. Chronic interleukin-1β in the dorsal hippocampus impairs behavioural pattern separation. Brain Behav Immun 2018; 74:252-264. [PMID: 30217534 DOI: 10.1016/j.bbi.2018.09.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/31/2018] [Accepted: 09/10/2018] [Indexed: 02/04/2023] Open
Abstract
Understanding the long-term consequences of chronic inflammation in the hippocampus may help to develop therapeutic targets for the treatment of cognitive disorders related to stress, ageing and neurodegeneration. The hippocampus is particularly vulnerable to increases in the pro-inflammatory cytokine interleukin-1β (IL-1β), a mediator of neuroinflammation, with elevated levels implicated in the aetiology of neurodegenerative diseases such as Alzheimer's and Parkinson's, and in stress-related disorders such as depression. Acute increases in hippocampal IL-1β have been shown to impair cognition and reduce adult hippocampal neurogenesis, the birth of new neurons. However, the impact of prolonged increases in IL-1β, as evident in clinical conditions, on cognition has not been fully explored. Therefore, the present study utilized a lentiviral approach to induce long-term overexpression of IL-1β in the dorsal hippocampus of adult male Sprague Dawley rats and examine its impact on cognition. Following three weeks of viral integration, pattern separation, a process involving hippocampal neurogenesis, was impaired in IL-1β-treated rats in both object-location and touchscreen operant paradigms. This was coupled with a decrease in the number and neurite complexity of immature neurons in the hippocampus. Conversely, tasks involving the hippocampus, but not sensitive to disruption of hippocampal neurogenesis, including spontaneous alternation, novel object and location recognition were unaffected. Touchscreen operant visual discrimination, a cognitive task involving the prefrontal cortex, was largely unaffected by IL-1β overexpression. In conclusion, these findings suggest that chronically elevated IL-1β in the hippocampus selectively impairs pattern separation. Inflammatory-mediated disruption of adult hippocampal neurogenesis may contribute to the cognitive decline associated with neurodegenerative and stress-related disorders.
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Affiliation(s)
- Cara M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - James D O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Alan E Hoban
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Danka A Kozareva
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Lauren C Pawley
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Olivia F O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland.
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Chandwani MN, Creisher PS, O'Donnell LA. Understanding the Role of Antiviral Cytokines and Chemokines on Neural Stem/Progenitor Cell Activity and Survival. Viral Immunol 2018; 32:15-24. [PMID: 30307795 DOI: 10.1089/vim.2018.0091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Viral infections of the central nervous system are accompanied by the expression of cytokines and chemokines that can be critical for the control of viral replication in the brain. The outcomes of cytokine/chemokine signaling in neural cells vary widely, with cell-specific effects on cellular activity, proliferation, and survival. Neural stem/progenitor cells (NSPCs) are often altered during viral infections, through direct infection by the virus or by the influence of immune cell activity or cytokine/chemokine signaling. However, it has been challenging to dissect the contribution of the virus and specific inflammatory mediators during an infection. In addition to initiating an antiviral program in infected NSPCs, cytokines/chemokines can induce multiple changes in NSPC behavior that can perturb NSPC numbers, differentiation into other neural cells, and migration to sites of injury, and ultimately brain development and repair. The focus of this review was to dissect the effects of common antiviral cytokines and chemokines on NSPC activity, and to consider the subsequent pathological consequences for the host from changes in NSPC function.
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Affiliation(s)
- Manisha N Chandwani
- Department of Pharmaceutical, Administrative, and Social Sciences, Graduate School of Pharmaceutical Sciences, Duquesne University School of Pharmacy , Pittsburgh, Pennsylvania
| | - Patrick S Creisher
- Department of Pharmaceutical, Administrative, and Social Sciences, Graduate School of Pharmaceutical Sciences, Duquesne University School of Pharmacy , Pittsburgh, Pennsylvania
| | - Lauren A O'Donnell
- Department of Pharmaceutical, Administrative, and Social Sciences, Graduate School of Pharmaceutical Sciences, Duquesne University School of Pharmacy , Pittsburgh, Pennsylvania
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29
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Park SY, Kang MJ, Han JS. Interleukin-1 beta promotes neuronal differentiation through the Wnt5a/RhoA/JNK pathway in cortical neural precursor cells. Mol Brain 2018; 11:39. [PMID: 29973222 PMCID: PMC6033214 DOI: 10.1186/s13041-018-0383-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/26/2018] [Indexed: 02/07/2023] Open
Abstract
Pro-inflammatory cytokine interleukin-1 beta (IL-1β) is a key mediator of inflammation and stress in the central nervous system (CNS), and is highly expressed in the developing brain. In this study, we investigated the possible role of IL-1β in neuronal differentiation of cortical neural precursor cells (NPCs). We showed that stimulation with IL-1β increased expression levels of neurotrophin-3 (NT3) and neurogenin 1 (Ngn1) and promoted neurite outgrowth. We also found that IL-1β increased mRNA and protein levels of Wnt5a. Knockdown of Wnt5a by transfection with Wnt5a siRNA inhibited IL-1β-induced neuronal differentiation. Moreover, IL-1β-induced Wnt5a expression was regulated by nuclear factor kappa B (NF-κB) activation, which is involved in IL-1β-mediated neuronal differentiation. To examine the role of Wnt5a in neuronal differentiation of NPCs, we exogenously added Wnt5a. We found that exogenous Wnt5a promotes neuronal differentiation, and activates the RhoA/Rho-associated kinase (ROCK)/c-jun N-terminal kinase (JNK) pathway. In addition, Wnt5a-induced neuronal differentiation was blocked by RhoA siRNA, as well as by a specific Rho-kinase inhibitor (Y27632) or a SAPK/JNK inhibitor (SP600125). Furthermore, treatment with RhoA siRNA, Y27632, or SP600125 suppressed the IL-1β-induced neuronal differentiation. Therefore, these results suggest that the sequential Wnt5a/RhoA/ROCK/JNK pathway is involved in IL-1β-induced neuronal differentiation of NPCs.
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Affiliation(s)
- Shin-Young Park
- Biomedical Research Institute and Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea
| | - Min-Jeong Kang
- Biomedical Research Institute and Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea
| | - Joong-Soo Han
- Biomedical Research Institute and Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea.
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30
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Ó'Léime CS, Hoban AE, Hueston CM, Stilling R, Moloney G, Cryan JF, Nolan YM. The orphan nuclear receptor TLX regulates hippocampal transcriptome changes induced by IL-1β. Brain Behav Immun 2018. [PMID: 29518529 DOI: 10.1016/j.bbi.2018.03.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
TLX is an orphan nuclear receptor highly expressed within neural progenitor cells (NPCs) in the hippocampus where is regulates proliferation. Inflammation has been shown to have negative effects on hippocampal function as well as on NPC proliferation. Specifically, the pro-inflammatory cytokine IL-1β suppresses NPC proliferation as well as TLX expression in the hippocampus. However, it is unknown whether TLX itself is involved in regulating the inflammatory response in the hippocampus. To explore the role of TLX in inflammation, we assessed changes in the transcriptional landscape of the hippocampus of TLX knockout mice (TLX-/-) compared to wildtype (WT) littermate controls with and without intrahippocampal injection of IL-1β using a whole transcriptome RNA sequencing approach. We demonstrated that there is an increase in the transcription of genes involved in the promotion of inflammation and regulation of cell chemotaxis (Tnf, Il1b, Cxcr1, Cxcr2, Tlr4) and a decrease in the expression of genes relating to synaptic signalling (Lypd1, Syt4, Cplx2) in cannulated TLX-/- mice compared to WT controls. We demonstrate that mice lacking in TLX share a similar increase in 176 genes involved in regulating inflammation (e.g. Cxcl1, Tnf, Il1b) as WT mice injected with IL-1β into the hippocampus. Moreover, TLX-/- mice injected with IL-1β displayed a blunted transcriptional profile compared to WT mice injected with IL-1β. Thus, TLX-/- mice, which already have an exaggerated inflammatory profile after cannulation surgery, are primed to respond differently to an inflammatory stimulus such as IL-1β. Together, these results demonstrate that TLX regulates hippocampal inflammatory transcriptome response to brain injury (in this case cannulation surgery) and cytokine stimulation.
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Affiliation(s)
- Ciarán S Ó'Léime
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Alan E Hoban
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Cara M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Roman Stilling
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Gerard Moloney
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland.
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31
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Henneghan AM, Palesh O, Harrison M, Kesler SR. Identifying cytokine predictors of cognitive functioning in breast cancer survivors up to 10 years post chemotherapy using machine learning. J Neuroimmunol 2018; 320:38-47. [PMID: 29759139 DOI: 10.1016/j.jneuroim.2018.04.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/28/2018] [Accepted: 04/17/2018] [Indexed: 12/20/2022]
Abstract
INTRODUCTION The purpose of this study is to explore 13 cytokine predictors of chemotherapy-related cognitive impairment (CRCI) in breast cancer survivors (BCS) 6 months to 10 years after chemotherapy completion using a multivariate, non-parametric approach. METHODS Cross sectional data collection included completion of a survey, cognitive testing, and non-fasting blood from 66 participants. Data were analyzed using random forest regression to identify the most significant predictors for each of the cognitive test scores. RESULTS A different cytokine profile predicted each cognitive test. Adjusted R2 for each model ranged from 0.71-0.77 (p's < 9.50-10). The relationships between all the cytokine predictors and cognitive test scores were non-linear. CONCLUSIONS Our findings are unique to the field of CRCI and suggest non-linear cytokine specificity to neural networks underlying cognitive functions assessed in this study.
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Affiliation(s)
- Ashley M Henneghan
- University of Texas MD Anderson Cancer Center, Neuro-Oncology, USA; University of Texas at Austin School of Nursing, USA.
| | - Oxana Palesh
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford University Cancer Institute, USA
| | | | - Shelli R Kesler
- University of Texas MD Anderson Cancer Center, Neuro-Oncology, USA
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32
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Ó’Léime CS, Kozareva DA, Hoban AE, Long‐Smith CM, Cryan JF, Nolan YM. TLX is an intrinsic regulator of the negative effects of IL‐1β on proliferating hippocampal neural progenitor cells. FASEB J 2018; 32:613-624. [DOI: 10.1096/fj.201700495r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Ciarán S. Ó’Léime
- Department of Anatomy and NeuroscienceUniversity College CorkCorkIreland
| | - Danka A. Kozareva
- Department of Anatomy and NeuroscienceUniversity College CorkCorkIreland
| | - Alan E. Hoban
- Department of Anatomy and NeuroscienceUniversity College CorkCorkIreland
| | - Caitriona M. Long‐Smith
- Department of Anatomy and NeuroscienceUniversity College CorkCorkIreland
- Alimentary Pharmabiotic Centre (APC) Microbiome InstituteUniversity College CorkCorkIreland
| | - John F. Cryan
- Department of Anatomy and NeuroscienceUniversity College CorkCorkIreland
- Alimentary Pharmabiotic Centre (APC) Microbiome InstituteUniversity College CorkCorkIreland
| | - Yvonne M. Nolan
- Department of Anatomy and NeuroscienceUniversity College CorkCorkIreland
- Alimentary Pharmabiotic Centre (APC) Microbiome InstituteUniversity College CorkCorkIreland
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33
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Chen JJ, Wang T, An CD, Jiang CY, Zhao J, Li S. Brain-derived neurotrophic factor: a mediator of inflammation-associated neurogenesis in Alzheimer's disease. Rev Neurosci 2018; 27:793-811. [PMID: 27508959 DOI: 10.1515/revneuro-2016-0017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/29/2016] [Indexed: 12/11/2022]
Abstract
In early- or late-onset Alzheimer's disease (AD), inflammation, which is triggered by pathologic conditions, influences the progression of neurodegeneration. Brain-derived neurotrophic factor (BDNF) has emerged as a crucial mediator of neurogenesis, because it exhibits a remarkable activity-dependent regulation of expression, which suggests that it may link inflammation to neurogenesis. Emerging evidence suggests that acute and chronic inflammation in AD differentially modulates neurotrophin functions, which are related to the roles of inflammation in neuroprotection and neurodegeneration. Recent studies also indicate novel mechanisms of BDNF-mediated neuroprotection, including the modulation of autophagy. Numerous research studies have demonstrated reverse parallel alterations between proinflammatory cytokines and BDNF during neurodegeneration; thus, we hypothesize that one mechanism that underlies the negative impact of chronic inflammation on neurogenesis is the reduction of BDNF production and function by proinflammatory cytokines.
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34
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Hueston CM, Cryan JF, Nolan YM. Adolescent social isolation stress unmasks the combined effects of adolescent exercise and adult inflammation on hippocampal neurogenesis and behavior. Neuroscience 2017; 365:226-236. [DOI: 10.1016/j.neuroscience.2017.09.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 08/21/2017] [Accepted: 09/12/2017] [Indexed: 12/14/2022]
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35
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Gkikas D, Tsampoula M, Politis PK. Nuclear receptors in neural stem/progenitor cell homeostasis. Cell Mol Life Sci 2017; 74:4097-4120. [PMID: 28638936 PMCID: PMC11107725 DOI: 10.1007/s00018-017-2571-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/06/2017] [Accepted: 06/13/2017] [Indexed: 12/13/2022]
Abstract
In the central nervous system, embryonic and adult neural stem/progenitor cells (NSCs) generate the enormous variety and huge numbers of neuronal and glial cells that provide structural and functional support in the brain and spinal cord. Over the last decades, nuclear receptors and their natural ligands have emerged as critical regulators of NSC homeostasis during embryonic development and adult life. Furthermore, substantial progress has been achieved towards elucidating the molecular mechanisms of nuclear receptors action in proliferative and differentiation capacities of NSCs. Aberrant expression or function of nuclear receptors in NSCs also contributes to the pathogenesis of various nervous system diseases. Here, we review recent advances in our understanding of the regulatory roles of steroid, non-steroid, and orphan nuclear receptors in NSC fate decisions. These studies establish nuclear receptors as key therapeutic targets in brain diseases.
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Affiliation(s)
- Dimitrios Gkikas
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, 4 Soranou Efesiou Str, 115 27, Athens, Greece
| | - Matina Tsampoula
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, 4 Soranou Efesiou Str, 115 27, Athens, Greece
| | - Panagiotis K Politis
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, 4 Soranou Efesiou Str, 115 27, Athens, Greece.
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36
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O'Léime CS, Cryan JF, Nolan YM. Nuclear deterrents: Intrinsic regulators of IL-1β-induced effects on hippocampal neurogenesis. Brain Behav Immun 2017; 66:394-412. [PMID: 28751020 DOI: 10.1016/j.bbi.2017.07.153] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/15/2017] [Accepted: 07/23/2017] [Indexed: 12/11/2022] Open
Abstract
Hippocampal neurogenesis, the process by which new neurons are born and develop into the host circuitry, begins during embryonic development and persists throughout adulthood. Over the last decade considerable insights have been made into the role of hippocampal neurogenesis in cognitive function and the cellular mechanisms behind this process. Additionally, an increasing amount of evidence exists on the impact of environmental factors, such as stress and neuroinflammation on hippocampal neurogenesis and subsequent impairments in cognition. Elevated expression of the pro-inflammatory cytokine interleukin-1β (IL-1β) in the hippocampus is established as a significant contributor to the neuronal demise evident in many neurological and psychiatric disorders and is now known to negatively regulate hippocampal neurogenesis. In order to prevent the deleterious effects of IL-1β on neurogenesis it is necessary to identify signalling pathways and regulators of neurogenesis within neural progenitor cells that can interact with IL-1β. Nuclear receptors are ligand regulated transcription factors that are involved in modulating a large number of cellular processes including neurogenesis. In this review we focus on the signalling mechanisms of specific nuclear receptors involved in regulating neurogenesis (glucocorticoid receptors, peroxisome proliferator activated receptors, estrogen receptors, and nuclear receptor subfamily 2 group E member 1 (NR2E1 or TLX)). We propose that these nuclear receptors could be targeted to inhibit neuroinflammatory signalling pathways associated with IL-1β. We discuss their potential to be therapeutic targets for neuroinflammatory disorders affecting hippocampal neurogenesis and associated cognitive function.
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Affiliation(s)
- Ciarán S O'Léime
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland.
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37
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Kozareva DA, Hueston CM, Ó'Léime CS, Crotty S, Dockery P, Cryan JF, Nolan YM. Absence of the neurogenesis-dependent nuclear receptor TLX induces inflammation in the hippocampus. J Neuroimmunol 2017; 331:87-96. [PMID: 28844503 DOI: 10.1016/j.jneuroim.2017.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/18/2017] [Accepted: 08/18/2017] [Indexed: 12/25/2022]
Abstract
The orphan nuclear receptor TLX (Nr2e1) is a key regulator of hippocampal neurogenesis. Impaired adult hippocampal neurogenesis has been reported in neurodegenerative and psychiatric conditions including dementia and stress-related depression. Neuroinflammation is also implicated in the neuropathology of these disorders, and has been shown to negatively affect hippocampal neurogenesis. To investigate a role for TLX in hippocampal neuroinflammation, we assessed microglial activation in the hippocampus of mice with a spontaneous deletion of TLX. Results from our study suggest that a lack of TLX is implicated in deregulation of microglial phenotype and that consequently, the survival and function of newborn cells in the hippocampus is impaired. TLX may be an important target in understanding inflammatory-associated impairments in neurogenesis.
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Affiliation(s)
- Danka A Kozareva
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Cara M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Ciarán S Ó'Léime
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Suzanne Crotty
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Peter Dockery
- Department of Anatomy, National University of Ireland, Galway, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland.
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38
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Maheu ME, Ressler KJ. Developmental pathway genes and neural plasticity underlying emotional learning and stress-related disorders. ACTA ACUST UNITED AC 2017; 24:492-501. [PMID: 28814475 PMCID: PMC5580529 DOI: 10.1101/lm.044271.116] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 05/18/2017] [Indexed: 11/24/2022]
Abstract
The manipulation of neural plasticity as a means of intervening in the onset and progression of stress-related disorders retains its appeal for many researchers, despite our limited success in translating such interventions from the laboratory to the clinic. Given the challenges of identifying individual genetic variants that confer increased risk for illnesses like depression and post-traumatic stress disorder, some have turned their attention instead to focusing on so-called “master regulators” of plasticity that may provide a means of controlling these potentially impaired processes in psychiatric illnesses. The mammalian homolog of Tailless (TLX), Wnt, and the homeoprotein Otx2 have all been proposed to constitute master regulators of different forms of plasticity which have, in turn, each been implicated in learning and stress-related disorders. In the present review, we provide an overview of the changing distribution of these genes and their roles both during development and in the adult brain. We further discuss how their distinct expression profiles provide clues as to their function, and may inform their suitability as candidate drug targets in the treatment of psychiatric disorders.
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Affiliation(s)
- Marissa E Maheu
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, Massachusetts 02478, USA
| | - Kerry J Ressler
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, Massachusetts 02478, USA
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39
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Hueston CM, Cryan JF, Nolan YM. Stress and adolescent hippocampal neurogenesis: diet and exercise as cognitive modulators. Transl Psychiatry 2017; 7:e1081. [PMID: 28375209 PMCID: PMC5416690 DOI: 10.1038/tp.2017.48] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 01/04/2017] [Accepted: 02/01/2017] [Indexed: 02/08/2023] Open
Abstract
Adolescence is a critical period for brain maturation. Deciphering how disturbances to the central nervous system at this time affect structure, function and behavioural outputs is important to better understand any long-lasting effects. Hippocampal neurogenesis occurs during development and continues throughout life. In adulthood, integration of these new cells into the hippocampus is important for emotional behaviour, cognitive function and neural plasticity. During the adolescent period, maturation of the hippocampus and heightened levels of hippocampal neurogenesis are observed, making alterations to neurogenesis at this time particularly consequential. As stress negatively affects hippocampal neurogenesis, and adolescence is a particularly stressful time of life, it is important to investigate the impact of stressor exposure at this time on hippocampal neurogenesis and cognitive function. Adolescence may represent not only a time for which stress can have long-lasting effects, but is also a critical period during which interventions, such as exercise and diet, could ameliorate stress-induced changes to hippocampal function. In addition, intervention at this time may also promote life-long behavioural changes that would aid in fostering increased hippocampal neurogenesis and cognitive function. This review addresses both the acute and long-term stress-induced alterations to hippocampal neurogenesis and cognition during the adolescent period, as well as changes to the stress response and pubertal hormones at this time which may result in differential effects than are observed in adulthood. We hypothesise that adolescence may represent an optimal time for healthy lifestyle changes to have a positive and long-lasting impact on hippocampal neurogenesis, and to protect against stress-induced deficits. We conclude that future research into the mechanisms underlying the susceptibility of the adolescent hippocampus to stress, exercise and diet and the consequent effect on cognition may provide insight into why adolescence may be a vital period for correct conditioning of future hippocampal function.
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Affiliation(s)
- C M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - J F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Y M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
- APC Microbiome Institute, University College Cork, Cork, Ireland
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40
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Vasic V, Schmidt MHH. Resilience and Vulnerability to Pain and Inflammation in the Hippocampus. Int J Mol Sci 2017; 18:ijms18040739. [PMID: 28362320 PMCID: PMC5412324 DOI: 10.3390/ijms18040739] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 03/17/2017] [Accepted: 03/27/2017] [Indexed: 02/07/2023] Open
Abstract
Increasing evidence demonstrates the importance of hippocampal neurogenesis, a fundamental mechanism of neuroplasticity associated with cognition and emotion, in correlation to neurodegenerative and psychiatric disorders. Neuropsychiatric disorders are often a result of chronic stress or pain followed by inflammation; all these conditions manifest cognitive deficits and impairments in neurogenesis. However, while some individuals are more susceptible to stress, others are able to adapt to new environments via mechanisms of resilience. In light of this emerging field and based on extensive research, the role of neurogenesis is summarized and presented as a potentially powerful therapeutic tool.
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Affiliation(s)
- Verica Vasic
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn²), Johannes Gutenberg University, School of Medicine, Mainz 55131, Germany.
| | - Mirko H H Schmidt
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn²), Johannes Gutenberg University, School of Medicine, Mainz 55131, Germany.
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41
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Dioscin relieves endotoxemia induced acute neuro-inflammation and protect neurogenesis via improving 5-HT metabolism. Sci Rep 2017; 7:40035. [PMID: 28059131 PMCID: PMC5216397 DOI: 10.1038/srep40035] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 11/30/2016] [Indexed: 12/16/2022] Open
Abstract
Sepsis, in addition to causing fatality, is an independent risk factor for cognitive impairment among sepsis survivors. The pathologic mechanism of endotoxemia induced acute neuro-inflammation still has not been fully understood. For the first time, we found the disruption of neurotransmitters 5-HT, impaired neurogenesis and activation of astrocytes coupled with concomitant neuro-inflammation were the potential pathogenesis of endotoxemia induced acute neuro-inflammation in sepsis survivors. In addition, dioscin a natural steroidal saponin isolated from Chinese medicinal herbs, enhanced the serotonergic system and produced anti-depressant effect by enhancing 5-HT levels in hippocampus. What is more, this finding was verified by metabolic analyses of hippocampus, indicating 5-HT related metabolic pathway was involved in the pathogenesis of endotoxemia induced acute neuro-inflammation. Moreover, neuro-inflammation and neurogenesis within hippocampus were indexed using quantitative immunofluorescence analysis of GFAP DCX and Ki67, as well as real-time RT-PCR analysis of some gene expression levels in hippocampus. Our in vivo and in vitro studies show dioscin protects hippocampus from endotoxemia induced cascade neuro-inflammation through neurotransmitter 5-HT and HMGB-1/TLR4 signaling pathway, which accounts for the dioscin therapeutic effect in behavioral tests. Therefore, the current findings suggest that dioscin could be a potential approach for the therapy of endotoxemia induced acute neuro-inflammation.
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Horgusluoglu E, Nudelman K, Nho K, Saykin AJ. Adult neurogenesis and neurodegenerative diseases: A systems biology perspective. Am J Med Genet B Neuropsychiatr Genet 2017; 174:93-112. [PMID: 26879907 PMCID: PMC4987273 DOI: 10.1002/ajmg.b.32429] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 01/29/2016] [Indexed: 12/21/2022]
Abstract
New neurons are generated throughout adulthood in two regions of the brain, the olfactory bulb and dentate gyrus of the hippocampus, and are incorporated into the hippocampal network circuitry; disruption of this process has been postulated to contribute to neurodegenerative diseases including Alzheimer's disease and Parkinson's disease. Known modulators of adult neurogenesis include signal transduction pathways, the vascular and immune systems, metabolic factors, and epigenetic regulation. Multiple intrinsic and extrinsic factors such as neurotrophic factors, transcription factors, and cell cycle regulators control neural stem cell proliferation, maintenance in the adult neurogenic niche, and differentiation into mature neurons; these factors act in networks of signaling molecules that influence each other during construction and maintenance of neural circuits, and in turn contribute to learning and memory. The immune system and vascular system are necessary for neuronal formation and neural stem cell fate determination. Inflammatory cytokines regulate adult neurogenesis in response to immune system activation, whereas the vasculature regulates the neural stem cell niche. Vasculature, immune/support cell populations (microglia/astrocytes), adhesion molecules, growth factors, and the extracellular matrix also provide a homing environment for neural stem cells. Epigenetic changes during hippocampal neurogenesis also impact memory and learning. Some genetic variations in neurogenesis related genes may play important roles in the alteration of neural stem cells differentiation into new born neurons during adult neurogenesis, with important therapeutic implications. In this review, we discuss mechanisms of and interactions between these modulators of adult neurogenesis, as well as implications for neurodegenerative disease and current therapeutic research. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Emrin Horgusluoglu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Radiology and Imaging Sciences, Center for Neuroimaging, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kelly Nudelman
- Department of Radiology and Imaging Sciences, Center for Neuroimaging, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kwangsik Nho
- Department of Radiology and Imaging Sciences, Center for Neuroimaging, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Andrew J. Saykin
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Radiology and Imaging Sciences, Center for Neuroimaging, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana
- Indiana Alzheimer Disease Center, Indiana University School of Medicine, Indianapolis, Indiana
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O'Leary JD, O'Leary OF, Cryan JF, Nolan YM. Regulation of behaviour by the nuclear receptor TLX. GENES BRAIN AND BEHAVIOR 2016; 17:e12357. [PMID: 27790850 DOI: 10.1111/gbb.12357] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 09/15/2016] [Accepted: 10/25/2016] [Indexed: 01/10/2023]
Abstract
The orphan nuclear receptor Tlx (Nr2e1) is a key regulator of both embryonic and adult hippocampal neurogenesis. Several different mouse models have been developed which target Tlx in vivo including spontaneous deletion models (from birth) and targeted and conditional knockouts. Although some conflicting findings have been reported, for the most part studies have demonstrated that Tlx is important in regulating processes that underlie neurogenesis, spatial learning, anxiety-like behaviour and interestingly, aggression. More recent data have demonstrated that disrupting Tlx during early life induces hyperactivity and that Tlx plays a role in emotional regulation. Moreover, there are sex- and age-related differences in some behaviours in Tlx knockout mice during adolescence and adulthood. Here, we discuss the role of Tlx in motor-, cognitive-, aggressive- and anxiety-related behaviours during adolescence and adulthood. We examine current evidence which provides insight into Tlx during neurodevelopment, and offer our thoughts on the function of Tlx in brain and behaviour. We further hypothesize that Tlx is a key target in understanding the emergence of neurobiological disorders during adolescence and early adulthood.
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Affiliation(s)
- J D O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - O F O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Institute, University College Cork, Cork, Ireland
| | - J F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Y M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
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Dyall SC, Mandhair HK, Fincham REA, Kerr DM, Roche M, Molina-Holgado F. Distinctive effects of eicosapentaenoic and docosahexaenoic acids in regulating neural stem cell fate are mediated via endocannabinoid signalling pathways. Neuropharmacology 2016; 107:387-395. [PMID: 27044662 DOI: 10.1016/j.neuropharm.2016.03.055] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 03/30/2016] [Accepted: 03/31/2016] [Indexed: 11/29/2022]
Abstract
Emerging evidence suggests a complex interplay between the endocannabinoid system, omega-3 fatty acids and the immune system in the promotion of brain self-repair. However, it is unknown if all omega-3 fatty acids elicit similar effects on adult neurogenesis and if such effects are mediated or regulated by interactions with the endocannabinoid system. This study investigated the effects of DHA and EPA on neural stem cell (NSC) fate and the role of the endocannabinoid signalling pathways in these effects. EPA, but not DHA, significantly increased proliferation of NSCs compared to controls, an effect associated with enhanced levels of the endocannabinoid 2-arachidonylglycerol (2-AG) and p-p38 MAPK, effects attenuated by pre-treatment with CB1 (AM251) or CB2 (AM630) receptor antagonists. Furthermore, in NSCs derived from IL-1β deficient mice, EPA significantly decreased proliferation and p-p38 MAPK levels compared to controls, suggesting a key role for IL-1β signalling in the effects observed. Although DHA similarly increased 2-AG levels in wild-type NSCs, there was no concomitant increase in proliferation or p-p38 MAPK activity. In addition, in NSCs from IL-1β deficient mice, DHA significantly increased proliferation without effects on p-P38 MAPK, suggesting effects of DHA are mediated via alternative signalling pathways. These results provide crucial new insights into the divergent effects of EPA and DHA in regulating NSC proliferation and the pathways involved, and highlight the therapeutic potential of their interplay with endocannabinoid signalling in brain repair.
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Affiliation(s)
- S C Dyall
- Department of Life Sciences, University of Roehampton, Whitelands College, London, UK; Faculty of Health and Social Sciences, Bournemouth University, Dorset, UK.
| | - H K Mandhair
- Department of Life Sciences, University of Roehampton, Whitelands College, London, UK
| | - R E A Fincham
- Department of Life Sciences, University of Roehampton, Whitelands College, London, UK
| | - D M Kerr
- Physiology, School of Medicine, National University of Ireland, Galway, Ireland; Pharmacology and Therapeutics, School of Medicine, National University of Ireland, Galway, Ireland; NCBES Centre for Pain Research and Neuroscience Centre, National University of Ireland, Galway, Ireland
| | - M Roche
- Physiology, School of Medicine, National University of Ireland, Galway, Ireland; NCBES Centre for Pain Research and Neuroscience Centre, National University of Ireland, Galway, Ireland
| | - F Molina-Holgado
- Department of Life Sciences, University of Roehampton, Whitelands College, London, UK
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Abstract
Immunomodulators regulate stem cell activity at all stages of development as well as during adulthood. Embryonic stem cell (ESC) proliferation as well as neurogenic processes during embryonic development are controlled by factors of the immune system. We review here immunophenotypic expression patterns of different stem cell types, including ESC, neural (NSC) and tissue-specific mesenchymal stem cells (MSC), and focus on immunodulatory properties of these cells. Immune and inflammatory responses, involving actions of cytokines as well as toll-like receptor (TLR) signaling are known to affect the differentiation capacity of NSC and MSC. Secretion of pro- and anti-inflammatory messengers by MSC have been observed as the consequence of TLR and cytokine activation and promotion of differentiation into specified phenotypes. As result of augmented differentiation capacity, stem cells secrete angiogenic factors including vascular endothelial growth factor, resulting in multifactorial actions in tissue repair. Immunoregulatory properties of tissue specific adult stem cells are put into the context of possible clinical applications.
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Neuroinflammation negatively affects adult hippocampal neurogenesis and cognition: can exercise compensate? Neurosci Biobehav Rev 2016; 61:121-31. [DOI: 10.1016/j.neubiorev.2015.12.004] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 11/20/2015] [Accepted: 12/09/2015] [Indexed: 01/09/2023]
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TLX-Its Emerging Role for Neurogenesis in Health and Disease. Mol Neurobiol 2016; 54:272-280. [PMID: 26738856 PMCID: PMC5219886 DOI: 10.1007/s12035-015-9608-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 12/03/2015] [Indexed: 02/07/2023]
Abstract
The orphan nuclear receptor TLX, also called NR2E1, is a factor important in the regulation of neural stem cell (NSC) self-renewal, neurogenesis, and maintenance. As a transcription factor, TLX is vital for the expression of genes implicated in neurogenesis, such as DNA replication, cell cycle, adhesion and migration. It acts by way of repressing or activating target genes, as well as controlling protein-protein interactions. Growing evidence suggests that dysregulated TLX acts in the initiation and progression of human disorders of the nervous system. This review describes recent knowledge about TLX expression, structure, targets, and biological functions, relevant to maintaining adult neural stem cells related to both neuropsychiatric conditions and certain nervous system tumours.
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The role of inflammatory cytokines as key modulators of neurogenesis. Trends Neurosci 2015; 38:145-57. [PMID: 25579391 DOI: 10.1016/j.tins.2014.12.006] [Citation(s) in RCA: 249] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 10/20/2014] [Accepted: 12/08/2014] [Indexed: 12/20/2022]
Abstract
Neurogenesis is an important process in the regulation of brain function and behaviour, highly active in early development and continuing throughout life. Recent studies have shown that neurogenesis is modulated by inflammatory cytokines in response to an activated immune system. To disentangle the effects of the different cytokines on neurogenesis, here we summarise and discuss in vitro studies on individual cytokines. We show that inflammatory cytokines have both a positive and negative role on proliferation and neuronal differentiation. Hence, this strengthens the notion that inflammation is involved in molecular and cellular mechanisms associated with complex cognitive processes and, therefore, that alterations in brain-immune communication are relevant to the development of neuropsychiatric disorders.
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Paniagua-Torija B, Arevalo-Martin A, Molina-Holgado E, Molina-Holgado F, Garcia-Ovejero D. Spinal cord injury induces a long-lasting upregulation of interleukin-1β in astrocytes around the central canal. Neuroscience 2014; 284:283-289. [PMID: 25453765 DOI: 10.1016/j.neuroscience.2014.10.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/23/2014] [Accepted: 10/08/2014] [Indexed: 01/25/2023]
Abstract
Under inflammatory conditions, interleukin-1β (IL-1β) modulates neural stem cells at neurogenic niches. Here we show that spinal cord injury in rats increases IL-1β expression in astrocytes located around the spinal cord ependyma, a region that also holds a neurogenic potential. IL-1β increases from day 1 after lesion, reaches maximal levels between days 3 and 7, and declines from 14 days to low levels after 28 days. At the time of maximal expression, periependymal upregulation of IL-1β extends beyond 5 mm from the epicenter of the lesion both rostral and caudally. Since IL-1β controls proliferation and cell fate of neural stem/precursor cells, its modulation in periependymal astrocytes might create an appropriate environment for cell replacement after injury.
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Affiliation(s)
- B Paniagua-Torija
- Laboratory of Neuroinflammation, Unidad de Neurologia Experimental, Hospital Nacional de Paraplejicos (SESCAM), 45071 Toledo, Spain.
| | - A Arevalo-Martin
- Laboratory of Neuroinflammation, Unidad de Neurologia Experimental, Hospital Nacional de Paraplejicos (SESCAM), 45071 Toledo, Spain.
| | - E Molina-Holgado
- Laboratory of Neuroinflammation, Unidad de Neurologia Experimental, Hospital Nacional de Paraplejicos (SESCAM), 45071 Toledo, Spain.
| | - F Molina-Holgado
- Neural Stem Cell Laboratory, Department of Life Sciences, Health Sciences Research Centre, University of Roehampton, London SW15 4JD, UK.
| | - D Garcia-Ovejero
- Laboratory of Neuroinflammation, Unidad de Neurologia Experimental, Hospital Nacional de Paraplejicos (SESCAM), 45071 Toledo, Spain.
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Islam MM, Zhang CL. TLX: A master regulator for neural stem cell maintenance and neurogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:210-6. [PMID: 24930777 DOI: 10.1016/j.bbagrm.2014.06.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/22/2014] [Accepted: 06/05/2014] [Indexed: 10/25/2022]
Abstract
The orphan nuclear receptor TLX, also known as NR2E1, is an essential regulator of neural stem cell (NSC) self-renewal, maintenance, and neurogenesis. In vertebrates, TLX is specifically localized to the neurogenic regions of the forebrain and retina throughout development and adulthood. TLX regulates the expression of genes involved in multiple pathways, such as the cell cycle, DNA replication, and cell adhesion. These roles are primarily performed through the transcriptional repression or activation of downstream target genes. Emerging evidence suggests that the misregulation of TLX might play a role in the onset and progression of human neurological disorders making this factor an ideal therapeutic target. Here, we review the current understanding of TLX function, expression, regulation, and activity significant to NSC maintenance, adult neurogenesis, and brain plasticity. This article is part of a Special Issue entitled: Nuclear receptors in animal development.
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Affiliation(s)
- Mohammed M Islam
- Department of Molecular Biology, 6000 Harry Hines Blvd., Dallas, TX 75390, USA
| | - Chun-Li Zhang
- Department of Molecular Biology, 6000 Harry Hines Blvd., Dallas, TX 75390, USA.
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