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Waddell J, Lin S, Carter K, Truong T, Hebert M, Ojeda N, Fan LW, Bhatt A, Pang Y. Early Postnatal Neuroinflammation Produces Key Features of Diffuse Brain White Matter Injury in Rats. Brain Sci 2024; 14:976. [PMID: 39451991 PMCID: PMC11505921 DOI: 10.3390/brainsci14100976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2024] [Revised: 09/20/2024] [Accepted: 09/24/2024] [Indexed: 10/26/2024] Open
Abstract
BACKGROUND Perinatal infection is a major risk factor for diffuse white matter injury (dWMI), which remains the most common form of neurological disability among very preterm infants. The disease primarily targets oligodendrocytes (OL) lineage cells in the white matter but also involves injury and/or dysmaturation of neurons of the gray matter. This study aimed to investigate whether neuroinflammation preferentially affects the cellular compositions of the white matter or gray matter. METHOD Neuroinflammation was initiated by intracerebral administration of lipopolysaccharide (LPS) to rat pups at postnatal (P) day 5, and neurobiological and behavioral outcomes were assessed between P6 and P21. RESULTS LPS challenge rapidly activates microglia and astrocytes, which is associated with the inhibition of OL and neuron differentiation leading to myelination deficits. Specifically, neuroinflammation reduces the immature OLs but not progenitors and causes acute axonal injury (β-amyloid precursor protein immunopositivity) and impaired dendritic maturation (reduced MAP2+ neural fiber density) in the cortical area at P7. Neuroinflammation also reduces the expression of doublecortin in the hippocampus, suggesting compromise in neurogenesis. Utilizing a battery of behavioral assessments, we found that LPS-exposed animals exhibited deficits in sensorimotor, neuromuscular, and cognitive domains. CONCLUSION Our overall results indicate that neuroinflammation alone in the early postnatal period can produce cardinal neuropathological features of dWMI.
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Affiliation(s)
- John Waddell
- Division of Neonatology, Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA; (J.W.); (K.C.); (N.O.); (L.-W.F.); (A.B.)
| | - Shuying Lin
- Department of Physical Therapy, School of Health-Related Professionals, University of Mississippi Medical Center, Jackson, MS 39216, USA;
| | - Kathleen Carter
- Division of Neonatology, Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA; (J.W.); (K.C.); (N.O.); (L.-W.F.); (A.B.)
| | - Tina Truong
- Undergraduate Summer Research Program, University of Mississippi Medical Center, Jackson, MS 39216, USA; (T.T.)
| | - May Hebert
- Undergraduate Summer Research Program, University of Mississippi Medical Center, Jackson, MS 39216, USA; (T.T.)
| | - Norma Ojeda
- Division of Neonatology, Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA; (J.W.); (K.C.); (N.O.); (L.-W.F.); (A.B.)
| | - Lir-Wan Fan
- Division of Neonatology, Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA; (J.W.); (K.C.); (N.O.); (L.-W.F.); (A.B.)
| | - Abhay Bhatt
- Division of Neonatology, Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA; (J.W.); (K.C.); (N.O.); (L.-W.F.); (A.B.)
| | - Yi Pang
- Division of Neonatology, Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA; (J.W.); (K.C.); (N.O.); (L.-W.F.); (A.B.)
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Rong J, Yang Y, Liang M, Zhong H, Li Y, Zhu Y, Sha S, Chen L, Zhou R. Neonatal inflammation increases hippocampal KCC2 expression through methylation-mediated TGF-β1 downregulation leading to impaired hippocampal cognitive function and synaptic plasticity in adult mice. J Neuroinflammation 2023; 20:15. [PMID: 36691035 PMCID: PMC9872321 DOI: 10.1186/s12974-023-02697-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 01/12/2023] [Indexed: 01/25/2023] Open
Abstract
The mechanisms by which neonatal inflammation leads to cognitive deficits in adulthood remain poorly understood. Inhibitory GABAergic synaptic transmission plays a vital role in controlling learning, memory and synaptic plasticity. Since early-life inflammation has been reported to adversely affect the GABAergic synaptic transmission, the aim of this study was to investigate whether and how neonatal inflammation affects GABAergic synaptic transmission resulting in cognitive impairment. Neonatal mice received a daily subcutaneous injection of lipopolysaccharide (LPS, 50 μg/kg) or saline on postnatal days 3-5. It was found that blocking GABAergic synaptic transmission reversed the deficit in hippocampus-dependent memory or the induction failure of long-term potentiation in the dorsal CA1 in adult LPS mice. An increase of mIPSCs amplitude was further detected in adult LPS mice indicative of postsynaptic potentiation of GABAergic transmission. Additionally, neonatal LPS resulted in the increased expression and function of K+-Cl--cotransporter 2 (KCC2) and the decreased expression of transforming growth factor-beta 1 (TGF-β1) in the dorsal CA1 during adulthood. The local TGF-β1 overexpression improved KCC2 expression and function, synaptic plasticity and memory of adult LPS mice. Adult LPS mice show hypermethylation of TGFb1 promoter and negatively correlate with reduced TGF-β1 transcripts. 5-Aza-deoxycytidine restored the changes in TGFb1 promoter methylation and TGF-β1 expression. Altogether, the results suggest that hypermethylation-induced reduction of TGF-β1 leads to enhanced GABAergic synaptic inhibition through increased KCC2 expression, which is a underlying mechanism of neonatal inflammation-induced hippocampus-dependent memory impairment in adult mice.
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Affiliation(s)
- Jing Rong
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Yang Yang
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Min Liang
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Haiquan Zhong
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Yingchun Li
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Yichao Zhu
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Sha Sha
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Lei Chen
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Rong Zhou
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
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Zhong H, Rong J, Yang Y, Liang M, Li Y, Zhou R. Neonatal inflammation via persistent TGF-β1 downregulation decreases GABA AR expression in basolateral amygdala leading to the imbalance of the local excitation-inhibition circuits and anxiety-like phenotype in adult mice. Neurobiol Dis 2022; 169:105745. [PMID: 35513229 DOI: 10.1016/j.nbd.2022.105745] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 11/29/2022] Open
Abstract
Neonatal inflammation can increase the risk of anxiety disorder in adulthood. The balance between glutamatergic excitatory and GABAergic inhibitory transmissions in the basolateral amygdala (BLA) plays a vital role in controlling anxiety state. Based on the reports that early-life inflammation had adverse effects on GABAergic system, the aim of this study was to investigate whether and how neonatal inflammation affects excitatory-inhibitory circuits in the BLA resulting in anxiety disorder. Neonatal mice received a daily subcutaneous injection of lipopolysaccharide (LPS, 50 μg/kg) or saline on postnatal days 3-5. LPS-treated mice developed anxiety behaviors accompanied by the hyperactivity of adrenal axis in adulthood. Electrophysiological study revealed the increase of postsynaptic neuronal excitability in the cortical-BLA excitatory synapses of LPS mice which could be recovered by bath-application of GABAAR agonist suggesting the impairment of GABAergic system in LPS mice. Compared with controls, GABAARα2 subunit expression and density of GABA-evoked current in BLA principal neurons were reduced in LPS mice. Additionally, neonatal LPS treatment resulted in the down-regulation of transforming growth factor-beta 1 (TGF-β1) expression and PKC signaling pathway in the adult BLA. The local TGF-β1 overexpression in the BLA improved GABAARα2 expression via up-regulating the activity of PKC signaling, which corrected GABAAR-mediated inhibition leading to the abolishment of anxiety-like change in adrenal axis regulation and behaviors in LPS mice. These data suggest the persistent TGF-β1deficit induces the down-regulation of GABAARα2 expression and subsequent disruption of the excitation-inhibition balance in the BLA circuits, which is the important mechanisms of neonatal inflammation-induced anxiety disorder.
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Affiliation(s)
- Haiquan Zhong
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Jing Rong
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Yang Yang
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Min Liang
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Yingchun Li
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Rong Zhou
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China.
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Early Life Events and Maturation of the Dentate Gyrus: Implications for Neurons and Glial Cells. Int J Mol Sci 2022; 23:ijms23084261. [PMID: 35457079 PMCID: PMC9031216 DOI: 10.3390/ijms23084261] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/08/2022] [Accepted: 04/11/2022] [Indexed: 12/15/2022] Open
Abstract
The dentate gyrus (DG), an important part of the hippocampus, plays a significant role in learning, memory, and emotional behavior. Factors potentially influencing normal development of neurons and glial cells in the DG during its maturation can exert long-lasting effects on brain functions. Early life stress may modify maturation of the DG and induce lifelong alterations in its structure and functioning, underlying brain pathologies in adults. In this paper, maturation of neurons and glial cells (microglia and astrocytes) and the effects of early life events on maturation processes in the DG have been comprehensively reviewed. Early postnatal interventions affecting the DG eventually result in an altered number of granule neurons in the DG, ectopic location of neurons and changes in adult neurogenesis. Adverse events in early life provoke proinflammatory changes in hippocampal glia at cellular and molecular levels immediately after stress exposure. Later, the cellular changes may disappear, though alterations in gene expression pattern persist. Additional stressful events later in life contribute to manifestation of glial changes and behavioral deficits. Alterations in the maturation of neuronal and glial cells induced by early life stress are interdependent and influence the development of neural nets, thus predisposing the brain to the development of cognitive and psychiatric disorders.
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Nicolas S, McGovern AJ, Hueston CM, O'Mahony SM, Cryan JF, O'Leary OF, Nolan YM. Prior maternal separation stress alters the dendritic complexity of new hippocampal neurons and neuroinflammation in response to an inflammatory stressor in juvenile female rats. Brain Behav Immun 2022; 99:327-338. [PMID: 34732365 DOI: 10.1016/j.bbi.2021.10.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 10/19/2021] [Accepted: 10/23/2021] [Indexed: 12/11/2022] Open
Abstract
Stress during critical periods of neurodevelopment is associated with an increased risk of developing stress-related psychiatric disorders, which are more common in women than men. Hippocampal neurogenesis (the birth of new neurons) is vulnerable to maternal separation (MS) and inflammatory stressors, and emerging evidence suggests that hippocampal neurogenesis is more sensitive to stress in the ventral hippocampus (vHi) than in the dorsal hippocampus (dHi). Although research into the effects of MS stress on hippocampal neurogenesis is well documented in male rodents, the effect in females remains underexplored. Similarly, reports on the impact of inflammatory stressors on hippocampal neurogenesis in females are limited, especially when female bias in the prevalence of stress-related psychiatric disorders begins to emerge. Thus, in this study we investigated the effects of MS followed by an inflammatory stressor (lipopolysaccharide, LPS) in early adolescence on peripheral and hippocampal inflammatory responses and hippocampal neurogenesis in juvenile female rats. We show that MS enhanced an LPS-induced increase in the pro-inflammatory cytokine IL-1β in the vHi but not in the dHi. However, microglial activation was similar following LPS alone or MS alone in both hippocampal regions, while MS prior to LPS reduced microglial activation in both dHi and vHi. The production of new neurons was unaffected by MS and LPS. MS and LPS independently reduced the dendritic complexity of new neurons, and MS exacerbated LPS-induced reductions in the complexity of distal dendrites of new neurons in the vHi but not dHi. These data highlight that MS differentially primes the physiological response to LPS in the juvenile female rat hippocampus.
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Affiliation(s)
- Sarah Nicolas
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Andrew J McGovern
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Cara M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Siobhain M O'Mahony
- 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
| | - 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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Shim SY, Cho SJ, Park EA. Neurodevelopmental Outcomes at 18-24 Months of Corrected Age in Very Low Birth Weight Infants with Late-onset Sepsis. J Korean Med Sci 2021; 36:e205. [PMID: 34490752 PMCID: PMC8422039 DOI: 10.3346/jkms.2021.36.e205] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 07/09/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Preterm infants are prone to sepsis owing to their immature innate immunity and prolonged hospitalization. We aimed to evaluate the association between late-onset sepsis (LOS) during hospitalization and neurodevelopmental delay at 18-24 months of corrected age in very low birth weight infants (VLBWIs), and to ascertain this association when adjusted for perinatal risk factors. METHODS This is a population-based study of VLBWIs born at 23-32 weeks of gestation between January 2014 and December 2017 who were enrolled in the Korean Neonatal Network. Bayley scales of infant development were evaluated at 18-24 months of corrected age in 2,098 infants. To test for LOS as a risk factor for neurodevelopmental delay, multiple logistic regression was used and adjusted for parental education status and clinical variables. RESULTS Blood culture positive LOS was identified in 419 (20.0%) infants. Cognitive and motor delays were found in 392 (18.7%) and 347 (16.5%) infants, respectively. When multivariate analysis was performed, LOS had a significant association with cognitive delay (odds ratio, 1.48; 95% confidence interval, 1.02-2.16), but no association with motor delay in VLBWIs. Both delays were significantly more frequent in cases of intraventricular hemorrhage (IVH) ≥ grade 3, periventricular leukomalacia (PVL), and intrauterine growth restriction (IUGR) and duration of mechanical ventilation. Male sex and necrotizing enterocolitis ≥ grade 2 had an effect on motor delay, whereas paternal college graduation affected cognitive delay. CONCLUSION In VLBWIs with LOS, there is a heightened risk of cognitive delays at 18-24 months of corrected age. Brain injury, such as severe IVH and PVL, duration of mechanical ventilation, and IUGR, were also associated with cognitive and motor delays.
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Affiliation(s)
- So-Yeon Shim
- Division of Neonatology, Department of Pediatrics, Ewha Womans University College of Medicine, Seoul, Korea.
| | - Su Jin Cho
- Division of Neonatology, Department of Pediatrics, Ewha Womans University College of Medicine, Seoul, Korea
| | - Eun Ae Park
- Division of Neonatology, Department of Pediatrics, Ewha Womans University College of Medicine, Seoul, Korea
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Leschik J, Lutz B, Gentile A. Stress-Related Dysfunction of Adult Hippocampal Neurogenesis-An Attempt for Understanding Resilience? Int J Mol Sci 2021; 22:7339. [PMID: 34298958 PMCID: PMC8305135 DOI: 10.3390/ijms22147339] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 12/16/2022] Open
Abstract
Newborn neurons in the adult hippocampus are regulated by many intrinsic and extrinsic cues. It is well accepted that elevated glucocorticoid levels lead to downregulation of adult neurogenesis, which this review discusses as one reason why psychiatric diseases, such as major depression, develop after long-term stress exposure. In reverse, adult neurogenesis has been suggested to protect against stress-induced major depression, and hence, could serve as a resilience mechanism. In this review, we will summarize current knowledge about the functional relation of adult neurogenesis and stress in health and disease. A special focus will lie on the mechanisms underlying the cascades of events from prolonged high glucocorticoid concentrations to reduced numbers of newborn neurons. In addition to neurotransmitter and neurotrophic factor dysregulation, these mechanisms include immunomodulatory pathways, as well as microbiota changes influencing the gut-brain axis. Finally, we discuss recent findings delineating the role of adult neurogenesis in stress resilience.
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Affiliation(s)
- Julia Leschik
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, 55128 Mainz, Germany;
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, 55128 Mainz, Germany;
- Leibniz Institute for Resilience Research (LIR), 55122 Mainz, Germany
| | - Antonietta Gentile
- Synaptic Immunopathology Lab, IRCCS San Raffaele Pisana, 00166 Rome, Italy;
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Wang G, Zhang H, Sun J, Zhang Y, He F, Zou J. Cyclosporin A impairs neurogenesis and cognitive abilities in brain development via the IFN-γ-Shh-BDNF pathway. Int Immunopharmacol 2021; 96:107744. [PMID: 33993101 DOI: 10.1016/j.intimp.2021.107744] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/15/2021] [Accepted: 04/29/2021] [Indexed: 01/07/2023]
Abstract
A wealth of evidence indicate that the peripheral immune activation alters brain development. However, it is still largely unclear whether and how peripheral immunosuppression affects neurodevelopment. Here, we found that the immunosuppressant cyclosporin A (CsA) decreased the number of BrdU+, BrdU+/DCX+, BrdU+/NeuN + cells in the hippocampus, impaired learning and memory and inhibited protein levels of the shh signaling pathway, including Shh, Smo and Gli1. However, the shh pathway receptor agonist SAG could block the impairment of cognitive ability and the decrease of hippocampal neurogenesis and brain-derived neurotrophic factor (BDNF) level induced by CsA. We also found that CsA decreased the level of interferon-gamma (IFN-γ), while up-regulation of IFN-γ altered the inhibitory effect of the shh signaling pathway and the decrease of BDNF induced by CsA. Collectively, these data indicate that peripheral CsA impairs neurogenesis and cognition in brain development through downregulating the IFN-γ-Shh-BDNF pathway. The present study guides us to correctly apply immunomodulatory drugs in early life and suggests that the IFN-γ-Shh-BDNF pathway may represent a novel protective target for neurodevelopment under the condition of immunosuppression.
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Affiliation(s)
- Ge Wang
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China; Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, 200032 Shanghai, People's Republic of China
| | - Hongyang Zhang
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Jiancong Sun
- Department of Radiation Oncology, First Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Yuwei Zhang
- Department of Anatomy, Wannan Medical College, Wuhu, Anhui, People's Republic of China
| | - Fen He
- Department of Radiation Oncology, First Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China.
| | - Juntao Zou
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China.
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Li W, Ali T, He K, Liu Z, Shah FA, Ren Q, Liu Y, Jiang A, Li S. Ibrutinib alleviates LPS-induced neuroinflammation and synaptic defects in a mouse model of depression. Brain Behav Immun 2021; 92:10-24. [PMID: 33181270 DOI: 10.1016/j.bbi.2020.11.008] [Citation(s) in RCA: 147] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/14/2020] [Accepted: 11/05/2020] [Indexed: 01/24/2023] Open
Abstract
Previous studies have demonstrated a close association between an altered immune system and major depressive disorders, and inhibition of neuroinflammation may represent an alternative mechanism to treat depression. Recently, the anti-inflammatory activity of ibrutinib has been reported. However, the effect of ibrutinib on neuroinflammation-induced depression and its underlying mechanism has not been comprehensively studied. Therefore, we aimed to elucidate the potential anti-depressive role and mechanism of ibrutinib against neuroinflammation-induced depression and synaptic defects. Our results showed that ibrutinib treatment significantly reduced lipopolysaccharide (LPS)-induced depressive-like behaviors and neuroinflammation via inhibiting NF-kB activation, decreasing proinflammatory cytokine levels, and normalizing redox signaling and its downstream components, including Nrf2, HO-1, and SOD2, as well as glial cell activation markers, such as Iba-1 and GFAP. Further, ibrutinib treatment inhibited LPS-activated inflammasome activation by targeting NLRP3/P38/Caspase-1 signaling. Interestingly, LPS reduced the number of dendritic spines and expression of BDNF, and synaptic-related markers, including PSD95, snap25, and synaptophysin, were improved by ibrutinib treatment in the hippocampal area of the mouse brain. In conclusion, our findings suggest that ibrutinib can alleviate neuroinflammation and synaptic defects, suggesting it has antidepressant potential against LPS-induced neuroinflammation and depression.
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Affiliation(s)
- Weifen Li
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
| | - Tahir Ali
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
| | - Kaiwu He
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Zizhen Liu
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
| | - Fawad Ali Shah
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China; Riphah Institute of Pharmaceutical Sciences, Riphah International University, Islamabad, Pakistan.
| | - Qingguo Ren
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China.
| | - Yan Liu
- The Seventh Affiliated Hospital of Sun Yat-Sen University, 628 Zhenyuan Rd., Guangming Dist., Shenzhen 518107, China.
| | - Anlong Jiang
- Department of Physiology, University of Toronto, Toronto, ON, Canada.
| | - Shupeng Li
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China; Campbell Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
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Zubareva OE, Postnikova TY, Grifluk AV, Schwarz AP, Smolensky IV, Karepanov AA, Vasilev DS, Veniaminova EA, Rotov AY, Kalemenev SV, Zaitsev AV. Exposure to bacterial lipopolysaccharidein early life affects the expression of ionotropic glutamate receptor genes and is accompanied by disturbances in long-term potentiation and cognitive functions in young rats. Brain Behav Immun 2020; 90:3-15. [PMID: 32726683 DOI: 10.1016/j.bbi.2020.07.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/21/2020] [Accepted: 07/22/2020] [Indexed: 01/20/2023] Open
Abstract
Infections in childhood play an essential role in the pathogenesis of cognitive and psycho-emotional disorders. One of the possible mechanisms of these impairments is changes in the functional properties of NMDA and AMPA glutamate receptors in the brain. We suggest that bacterial infections during the early life period, which is critical for excitatory synapse maturation, can affect the subunit composition of NMDA and AMPA receptors. In the present study, we investigated the effect of repetitive lipopolysaccharide (LPS) intraperitoneal (i.p.) administration (25 μg/kg/day on P14, 16, and 18), mimicking an infectious disease, on the expression of subunits of NMDA and AMPA receptors in young rats. We revealed a substantial decrease of GluN2B subunit expression in the hippocampus at P23 using Western blot analysis and real-time polymerase chain reaction assay. Moderate changes were also found in GluN1, GluN2A, and GluA1 mRNA expression. The LPS-treated rats exhibited decreased exploratory and locomotor activity in the open field test and the impairment of spatial learning in the Morris water maze. Behavioral impairments were accompanied by a significant reduction in long-term hippocampal synaptic potentiation. Our data indicate that LPS-treatment in the critical period for excitatory synapse maturation alters ionotropic glutamate receptor gene expression, disturbs synaptic plasticity, and alters behavior.
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Affiliation(s)
- Olga E Zubareva
- Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia; Laboratory of Neurobiology of the Brain Integrative Functions, Pavlov Department of Physiology, Institute of Experimental Medicine, St. Petersburg, Russia
| | - Tatyana Y Postnikova
- Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Alexandra V Grifluk
- Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Alexander P Schwarz
- Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Ilya V Smolensky
- Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Anton A Karepanov
- Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Dmitry S Vasilev
- Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Ekaterina A Veniaminova
- Laboratory of Neurobiology of the Brain Integrative Functions, Pavlov Department of Physiology, Institute of Experimental Medicine, St. Petersburg, Russia
| | - Alexander Y Rotov
- Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Sergey V Kalemenev
- Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Aleksey V Zaitsev
- Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.
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Kudryashova I, Stepanichev M, Manolova A, Gulyaeva N. Deficit of Long-Term Potentiation Induction, but Not Maintenance, in the Juvenile Hippocampus after Neonatal Proinflammatory Stress. Dev Neurosci 2020; 41:318-326. [PMID: 32369803 DOI: 10.1159/000507347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 03/19/2020] [Indexed: 11/19/2022] Open
Abstract
CA3-CA1 long-term potentiation (LTP) in the hippocampal slices from juvenile Wistar rats was studied to reveal factors potentially contributing to different sensitivity to neonatal proinflammatory stress (NPS). NPS was induced by intra-peritoneal injections of bacterial lipopolysaccharide (LPS) to neonatal rats (two injections of LPS, or saline in the control group, consecutively on postnatal days 3 and 5 [PND3 and PND5]). In females, a significant effect of NPS on hippocampus development was associated with modifications of long-term synaptic plasticity, the synapses becoming more resistant to LTP induction. LTP deficit in the slices of the NPS group was not associated with a decrease in LTP maintenance, since late LTP generally corresponded to early LTP magnitude, similar in all groups. Moreover, partial correlation revealed significantly higher residual LTP 1 h after high-frequency stimulation in the NPS groups compared to the corresponding value of early LTP in the control groups, suggesting improved consolidation. Both effects were evident in NPS females. A number of males responded to NPS similarly to females, while others were relatively resistant to NPS exposure, a significant increase in variability of LTP magnitude being revealed in NPS males compared to respective females and the control groups. We suggest that postnatal development of long-term plasticity after NPS is similar in animals of both sexes; however, additional specific factor(s) may promote a relative resistance of the male brain.
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Affiliation(s)
- Irina Kudryashova
- Laboratory of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Mikhail Stepanichev
- Laboratory of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russian Federation,
| | - Anna Manolova
- Laboratory of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Natalia Gulyaeva
- Laboratory of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russian Federation
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12
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Liang M, Zhong H, Rong J, Li Y, Zhu C, Zhou L, Zhou R. Postnatal Lipopolysaccharide Exposure Impairs Adult Neurogenesis and Causes Depression-like Behaviors Through Astrocytes Activation Triggering GABAA Receptor Downregulation. Neuroscience 2019; 422:21-31. [DOI: 10.1016/j.neuroscience.2019.10.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 09/30/2019] [Accepted: 10/14/2019] [Indexed: 01/20/2023]
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13
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Noailles A, Kutsyr O, Maneu V, Ortuño-Lizarán I, Campello L, de Juan E, Gómez-Vicente V, Cuenca N, Lax P. The Absence of Toll-Like Receptor 4 Mildly Affects the Structure and Function in the Adult Mouse Retina. Front Cell Neurosci 2019; 13:59. [PMID: 30873007 PMCID: PMC6401850 DOI: 10.3389/fncel.2019.00059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/05/2019] [Indexed: 12/26/2022] Open
Abstract
The innate immune Toll-like receptor (TLR) family plays essential roles in cell proliferation, survival and function of the central nervous system. However, the way in which TLRs contribute to the development and maintenance of proper retinal structure and function remains uncertain. In this work, we assess the effect of genetic TLR4 deletion on the morphology and function of the retina in mice. Visual acuity and retinal responsiveness were evaluated in TLR4 knockout and wild type C57BL/6J control mice by means of an optomotor test and electroretinography, respectively, from P20 to P360. Retinal structure was also analyzed in both strains using confocal and electron microscopy. ERG data showed impaired retinal responsiveness in TLR4 KO mice, in comparison to wild type animals. The amplitudes of the scotopic a-waves were less pronounced in TLR4-deficient mice than in wild-type animals from P30 to P360, and TLR4 KO mice presented scotopic b-wave amplitudes smaller than those of age-matched control mice at all ages studied (P20 to P360). Visual acuity was also relatively poorer in TLR4 KO as compared to C57BL/6J mice from P20 to P360, with significant differences at P30 and P60. Immunohistochemical analysis of retinal vertical sections showed no differences between TLR4 KO and C57BL/6J mice, in terms of either photoreceptor number or photoreceptor structure. Horizontal cells also demonstrated no morphological differences between TLR4 KO and wild-type mice. However, TLR4 KO mice exhibited a lower density of bipolar cells (15% less at P30) and thus fewer bipolar cell dendrites than the wild type control mouse, even though both confocal and electron microscopy images showed no morphologic abnormalities in the synaptic contacts between the photoreceptors and second order neurons. Microglial cell density was significantly lower (26% less at P30) in TLR4 KO mice as compared to wild-type control mice. These results suggest that TLR4 deletion causes functional alterations in terms of visual response and acuity, probably through the loss of bipolar cells and microglia, but this receptor is not essential for the processing of visual information in the retina.
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Affiliation(s)
- Agustina Noailles
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Oksana Kutsyr
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Isabel Ortuño-Lizarán
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Laura Campello
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Emilio de Juan
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Violeta Gómez-Vicente
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain.,Institute Ramón Margalef, University of Alicante, Alicante, Spain
| | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
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14
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Cai B, Seong KJ, Bae SW, Kook MS, Chun C, Lee JH, Choi WS, Jung JY, Kim WJ. Water-Soluble Arginyl–Diosgenin Analog Attenuates Hippocampal Neurogenesis Impairment Through Blocking Microglial Activation Underlying NF-κB and JNK MAPK Signaling in Adult Mice Challenged by LPS. Mol Neurobiol 2019; 56:6218-6238. [DOI: 10.1007/s12035-019-1496-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 01/15/2019] [Indexed: 12/20/2022]
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15
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Thei L, Rocha-Ferreira E, Peebles D, Raivich G, Hristova M. Extracellular signal-regulated kinase 2 has duality in function between neuronal and astrocyte expression following neonatal hypoxic-ischaemic cerebral injury. J Physiol 2018; 596:6043-6062. [PMID: 29873394 PMCID: PMC6265549 DOI: 10.1113/jp275649] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 05/29/2018] [Indexed: 01/08/2023] Open
Abstract
Key points This study identifies phosphorylated extracellular signal‐regulated kinase (ERK) to be immediately diminished followed by a rapid if transient increase for up to 4 h following hypoxic–ischaemic insult (HI) in the neonatal mouse. Phosphorylated ERK up‐regulation was prevented with systemic injection of the mitogen‐activated protein kinase kinase (MEK) inhibitor SL327. Treatment with SL327 both pre‐ and post‐HI gave a strong reduction in the number of dying cells and microgliosis. By utilising transgenic mouse mutations, we observe that neuronal ERK2 significantly contributes to tissue damage, while ERK1 and astrocytic ERK2 are neuroprotective. Compared to global inactivation, selective cell‐specific interference with ERK activity could result in stronger neuroprotection.
Abstract Hypoxia–ischaemia (HI) is a major cause of neonatal brain injury resulting in cerebral palsy, epilepsy, cognitive impairment and other neurological disabilities. The role of extracellular signal‐regulated kinase (ERK) isoforms and their mitogen‐activated protein kinase kinase (MEK)‐dependent phosphorylation in HI has previously been explored but remains unresolved at cellular level. This is pertinent given the growing awareness of the role of non‐neuronal cells in neuroprotection. Using a modified Rice–Vannucci model of HI in the neonatal mouse we observed time‐ and cell‐dependent ERK phosphorylation (pERK), with strongly up‐regulated pERK immunoreactivity first in periventricular white matter axons within 15–45 min of HI, followed by forebrain astrocytes and neurons (1–4 h post‐HI), and return to baseline by 16 h. We explored the effects of pharmacological ERK blockade through the MEK inhibitor SL327 on neonatal HI‐brain damage following HI alone (30 or 60 min) or lipopolysaccharide (LPS)‐sensitised HI insult (30 min). Global inhibition of ERK phosphorylation with systemically applied SL327 abolished forebrain pERK immunoreactivity, and significantly reduced cell death and associated microglial activation at 48 h post‐HI. We then explored the effects of cell‐specific ERK2 deletion alone or in combination with global ERK1 knockout under the same conditions of HI insult. Neuronal ERK2 deletion strongly decreased infarct size, neuronal cell death and microglial activation in grey matter following both HI alone or LPS‐sensitised HI. ERK1 deletion attenuated the protective effect of neuronal ERK2 deletion. Removal of astroglial ERK2 produced a reverse response, with a 3‐ to 4‐fold increase in microglial activation and cell death. Our data suggest a cell‐specific and time‐dependent role of ERK in neonatal HI, with a predominant, neurotoxic effect of neuronal ERK2, which is counteracted by neuroprotection by ERK1 and astrocytic ERK2. Overall, global pharmacological inhibition of ERK phosphorylation is strongly neuroprotective. This study identifies phosphorylated extracellular signal‐regulated kinase (ERK) to be immediately diminished followed by a rapid if transient increase for up to 4 h following hypoxic–ischaemic insult (HI) in the neonatal mouse. Phosphorylated ERK up‐regulation was prevented with systemic injection of the mitogen‐activated protein kinase kinase (MEK) inhibitor SL327. Treatment with SL327 both pre‐ and post‐HI gave a strong reduction in the number of dying cells and microgliosis. By utilising transgenic mouse mutations, we observe that neuronal ERK2 significantly contributes to tissue damage, while ERK1 and astrocytic ERK2 are neuroprotective. Compared to global inactivation, selective cell‐specific interference with ERK activity could result in stronger neuroprotection.
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Affiliation(s)
- Laura Thei
- UCL Institute for Women's Health, Maternal and Fetal Medicine, Perinatal Brain Repair Group, London, WC1E 6HX, UK.,School of Pharmacy, University of Reading, Reading, RG6 6UA, UK
| | - Eridan Rocha-Ferreira
- UCL Institute for Women's Health, Maternal and Fetal Medicine, Perinatal Brain Repair Group, London, WC1E 6HX, UK.,Institute of Clinical Sciences, University of Gothenburg, Gothenburg, SE 416 85, Sweden
| | - Donald Peebles
- UCL Institute for Women's Health, Maternal and Fetal Medicine, Perinatal Brain Repair Group, London, WC1E 6HX, UK
| | - Gennadij Raivich
- UCL Institute for Women's Health, Maternal and Fetal Medicine, Perinatal Brain Repair Group, London, WC1E 6HX, UK
| | - Mariya Hristova
- UCL Institute for Women's Health, Maternal and Fetal Medicine, Perinatal Brain Repair Group, London, WC1E 6HX, UK
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16
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Wang G, He F, Xu Y, Zhang Y, Wang X, Zhou C, Huang Y, Zou J. Immunopotentiator Thymosin Alpha-1 Promotes Neurogenesis and Cognition in the Developing Mouse via a Systemic Th1 Bias. Neurosci Bull 2017; 33:675-684. [PMID: 28780644 DOI: 10.1007/s12264-017-0162-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 05/03/2017] [Indexed: 01/19/2023] Open
Abstract
In early life, the immune system plays an essential role in brain development. In our study, the immunopotentiator thymosin alpha-1 (Ta1) was peripherally administered to neonatal mice to explore whether the peripheral immunopotentiator affects neurodevelopment and cognition, and to further investigate the relevant mechanism. Compared with the control group, the Ta1 mice displayed better cognitive abilities in early life. The numbers of 5-bromodeoxyuridine (BrdU)+, nestin+, T-box transcription factor 2 (Tbr2)+, BrdU+/doublecortin (DCX)+, BrdU+/ionized calcium-binding adaptor molecule 1 (Iba1)+, and BrdU+/neuronal nuclei (NeuN)+ cells in the hippocampus were increased in the Ta1 group, accompanied by increased interleukin-4 (IL-4), interferon-gamma, brain-derived neurotrophic factor, nerve growth factor, and insulin-like growth factor-1 as well as decreased IL-6 and tumor necrosis factor-α. Furthermore, the Ta1-group showed a Th1-polarized immune response, and the neurotrophic factors were positively associated with the Th1/Th2 ratio. More importantly, administration of Ta1 blocked lipopolysaccharide-induced impairment of hippocampal neurogenesis in early life. These findings suggest that peripheral Ta1 contributes to neurogenesis and cognition probably through a systemic Th1 bias, as well as neuroprotection against LPS infection by Ta1.
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Affiliation(s)
- Ge Wang
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Fen He
- Department of Radiation Oncology, First Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510120, China
| | - Yunlong Xu
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.,South China Research Center for Acupuncture and Moxibustion, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Yuwei Zhang
- Department of Anatomy, Wannan Medical College, Wuhu, 241002, China
| | - Xiao Wang
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Chunhua Zhou
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Yihong Huang
- Department of Neurology, The Fifth Affiliated Hospital of Southern Medical University, Guangzhou, 510900, China.
| | - Juntao Zou
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.
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17
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Mottahedin A, Ardalan M, Chumak T, Riebe I, Ek J, Mallard C. Effect of Neuroinflammation on Synaptic Organization and Function in the Developing Brain: Implications for Neurodevelopmental and Neurodegenerative Disorders. Front Cell Neurosci 2017; 11:190. [PMID: 28744200 PMCID: PMC5504097 DOI: 10.3389/fncel.2017.00190] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/20/2017] [Indexed: 12/27/2022] Open
Abstract
The brain is a plastic organ where both the intrinsic CNS milieu and extrinsic cues play important roles in shaping and wiring neural connections. The perinatal period constitutes a critical time in central nervous system development with extensive refinement of neural connections, which are highly sensitive to fetal and neonatal compromise, such as inflammatory challenges. Emerging evidence suggests that inflammatory cells in the brain such as microglia and astrocytes are pivotal in regulating synaptic structure and function. In this article, we will review the role of glia cells in synaptic physiology and pathophysiology, including microglia-mediated elimination of synapses. We propose that activation of the immune system dynamically affects synaptic organization and function in the developing brain. We will discuss the role of neuroinflammation in altered synaptic plasticity following perinatal inflammatory challenges and potential implications for neurodevelopmental and neurodegenerative disorders.
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Affiliation(s)
- Amin Mottahedin
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
| | - Maryam Ardalan
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
| | - Tetyana Chumak
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
| | - Ilse Riebe
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
| | - Joakim Ek
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
| | - Carina Mallard
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
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18
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ALCAR promote adult hippocampal neurogenesis by regulating cell-survival and cell death-related signals in rat model of Parkinson's disease like-phenotypes. Neurochem Int 2017; 108:388-396. [PMID: 28577987 DOI: 10.1016/j.neuint.2017.05.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/24/2017] [Accepted: 05/30/2017] [Indexed: 12/25/2022]
Abstract
Parkinson's disease (PD) is characterized by the degeneration of dopaminergic neurons in the nigrostriatal pathway that leading to progressive motor and nonmotor symptoms. The formation of newborn neurons in the adult hippocampus is affected by many factors such as anxiety, depression and impairment in learning and memory that are commonly observed nonmotor symptoms in PD, indicating the role of adult neurogenesis in PD pathophysiology. Acetyl-l-carnitine (ALCAR), regulate mitochondrial metabolism and has been reported to improve cognitive functions in different neurodegenerative disorders through an unknown mechanism. For the first time, we investigated the effect of ALCAR on adult neurogenesis in the 6-hydroxydopamine (6-OHDA) induced rat model of PD-like phenotypes and also explored the possible underlying mechanism of action. A single unilateral administration of 6-OHDA into the medial forebrain bundle reduced neural progenitor cell (NPC) proliferation, long-term survival and neuronal differentiation in the hippocampus. Interestingly, chronic treatment with ALCAR (100 mg/kg/day, i.p) potentially enhanced proliferation, long term survival and neuronal differentiation of NPCs in rat model of PD-like phenotypes. ALCAR treatment stimulates cell survival related signals (AKT and BCL-2) by inhibiting cell death related cues (GSK-3β and BAX) which might be responsible for a neuroprotective effect of ALCAR in rat model of PD-like phenotypes. We conclude that ALCAR exerts neuroprotective effects against 6-OHDA-induced impairment in hippocampal neurogenesis by regulating cell survival and cell death-related signals.
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19
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Postnatal LPS Challenge Impacts Escape Learning and Expression of Plasticity Factors Mmp9 and Timp1 in Rats: Effects of Repeated Training. Neurotox Res 2017; 32:175-186. [PMID: 28421528 PMCID: PMC5493723 DOI: 10.1007/s12640-017-9720-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 03/01/2017] [Accepted: 03/03/2017] [Indexed: 10/24/2022]
Abstract
Bacterial intoxication associated with inflammatory conditions during development can impair brain functions, in particular evolutionarily novel forms of memory, such as explicit learning. Little is known about the dangers of early-life inflammation on more basic forms of learning, for example, the acquisition of motor escape abilities, which are generally better preserved under pathological conditions. To address this limitation in knowledge, an inflammatory response was elicited in Wistar pups by lipopolysaccharide (LPS) injections (25 μg/kg) on postnatal days P15, P18 and P21. The acquisition of escape behaviour was tested from P77 by active avoidance footshock model and water maze. Open-field behaviour and blood corticosterone levels were also measured. Rat brain tissue was collected from pups 2 h post-injection and from adult rats which either underwent escape training on P77-P81 or remained untrained. mRNA levels of developmental brain plasticity factors MMP-9 and TIMP-1 were investigated in the medial prefrontal cortex and ventral/dorsal hippocampus. LPS-challenged rats displayed moderately deficient escape responses in both memory tests, increased freezing behaviour and, surprisingly, reduced blood cortisol levels. Mmp9 and Timp1, and their ratio to one another, were differentially altered in pups versus adult untrained rats but remained unchanged overall in rats trained in either learning task. Together, our data indicate that systemic pro-inflammatory response during early postnatal development has long-lasting effects, including on the acquisition of motor escape abilities and plasticity factor expression, into adulthood. Our data suggest that altered stress response could possibly mediate these deviations and repeated training might generate positive effects on plasticity under the employed conditions.
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20
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Pierre WC, Smith PLP, Londono I, Chemtob S, Mallard C, Lodygensky GA. Neonatal microglia: The cornerstone of brain fate. Brain Behav Immun 2017; 59:333-345. [PMID: 27596692 DOI: 10.1016/j.bbi.2016.08.018] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/30/2016] [Accepted: 08/29/2016] [Indexed: 12/16/2022] Open
Abstract
Microglia, mainly known for their role in innate immunity and modulation of neuroinflammation, play an active role in central nervous system development and homeostasis. Depending on the context and environmental stimuli, microglia adopt a broad spectrum of activation status from pro-inflammatory, associated with neurotoxicity, to anti-inflammatory linked to neuroprotection. Pro-inflammatory microglial activation is a key hallmark of white matter injury in preterm infants and is involved in developmental origin of adult neurological diseases. Characterization of neonatal microglia function in brain development and inflammation has allowed the investigation of promising therapeutic targets with potential long-lasting neuroprotective effects. True prevention of neuro-degenerative diseases might eventually occur as early as the perinatal period.
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Affiliation(s)
- Wyston C Pierre
- Sainte-Justine Hospital and Research Center, Department of Pediatrics, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, Canada
| | - Peter L P Smith
- Perinatal Center, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Irène Londono
- Sainte-Justine Hospital and Research Center, Department of Pediatrics, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, Canada
| | - Sylvain Chemtob
- Sainte-Justine Hospital and Research Center, Department of Pediatrics, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, Canada; Departments of Ophtalmology, Université de Montréal, Montreal, Quebec, Canada; Departments of Pharmacology, Université de Montréal, Montreal, Quebec, Canada
| | - Carina Mallard
- Perinatal Center, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Gregory A Lodygensky
- Sainte-Justine Hospital and Research Center, Department of Pediatrics, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, Canada; Montreal Heart Institute, 5000 Rue Bélanger, Montreal, Quebec, Canada; Department of Neuroscience, Université de Montréal, Montreal, Quebec, Canada; Departments of Pharmacology, Université de Montréal, Montreal, Quebec, Canada.
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21
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Saavedra LM, Fenton Navarro B, Torner L. Early Life Stress Activates Glial Cells in the Hippocampus but Attenuates Cytokine Secretion in Response to an Immune Challenge in Rat Pups. Neuroimmunomodulation 2017; 24:242-255. [PMID: 29332092 DOI: 10.1159/000485383] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 10/04/2017] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE Early life stress (ELS) increases the vulnerability to developing psychopathological disorders in adulthood that are accompanied by brain inflammatory processes. However, it is not known how a combined double hit (stress and immune) at an early age affects the response of the neuroimmune system. Here we investigated the effect of periodic maternal separation (MS) followed by administration of lipopolysaccharide (LPS) on glial cells in the CA3 region and hilus of the hippocampus and on cytokine release on postnatal day (PN) 15. METHODS Male rat pups were subjected to MS (3 h/day, PN1-14). MS and control pups received a single LPS injection (1 mg/kg of body weight) on PN14. They were subjected to an open field test 1 h later. The pups were sacrificed 90 min after LPS injection (PN14) or on PN15 for cytokine or immunohistological analyses, respectively. RESULTS LPS reduced the locomotion and induced high corticosterone levels in treated pups. MS or LPS reduced microglial density and activated microglial cells in the hippocampal CA3 and hilus regions. Microglial activation was highest in MS-LPS pups. The astrocyte density was mildly reduced by MS or LPS in the CA3 region and hilus, but the reduction was maximal in MS-LPS pups. LPS increased the secretion of plasmatic interleukin (IL)-1β, tumor necrosis factor-α, and IL-6, and of hippocampal IL-1β protein, but these were attenuated in MS-LPS pups. CONCLUSION Although MS and LPS activate neuroimmune cells, stress attenuates the hippocampal and peripheral cytokine response to LPS through an as-yet unidentified adaptive mechanism. These results provide information regarding the neurobiology of stress and inflammation.
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Affiliation(s)
- Luis Miguel Saavedra
- Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social, Morelia, Mexico
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22
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Saito M, Chakraborty G, Hui M, Masiello K, Saito M. Ethanol-Induced Neurodegeneration and Glial Activation in the Developing Brain. Brain Sci 2016; 6:brainsci6030031. [PMID: 27537918 PMCID: PMC5039460 DOI: 10.3390/brainsci6030031] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 08/05/2016] [Accepted: 08/12/2016] [Indexed: 11/16/2022] Open
Abstract
Ethanol induces neurodegeneration in the developing brain, which may partially explain the long-lasting adverse effects of prenatal ethanol exposure in fetal alcohol spectrum disorders (FASD). While animal models of FASD show that ethanol-induced neurodegeneration is associated with glial activation, the relationship between glial activation and neurodegeneration has not been clarified. This review focuses on the roles of activated microglia and astrocytes in neurodegeneration triggered by ethanol in rodents during the early postnatal period (equivalent to the third trimester of human pregnancy). Previous literature indicates that acute binge-like ethanol exposure in postnatal day 7 (P7) mice induces apoptotic neurodegeneration, transient activation of microglia resulting in phagocytosis of degenerating neurons, and a prolonged increase in glial fibrillary acidic protein-positive astrocytes. In our present study, systemic administration of a moderate dose of lipopolysaccharides, which causes glial activation, attenuates ethanol-induced neurodegeneration. These studies suggest that activation of microglia and astrocytes by acute ethanol in the neonatal brain may provide neuroprotection. However, repeated or chronic ethanol can induce significant proinflammatory glial reaction and neurotoxicity. Further studies are necessary to elucidate whether acute or sustained glial activation caused by ethanol exposure in the developing brain can affect long-lasting cellular and behavioral abnormalities observed in the adult brain.
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Affiliation(s)
- Mariko Saito
- Division of Neurochemisty, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA.
- Department of Psychiatry, New York University Langone Medical Center, 550 First Avenue, New York, NY 10016, USA.
| | - Goutam Chakraborty
- Division of Neurochemisty, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA.
| | - Maria Hui
- Division of Neurochemisty, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA.
| | - Kurt Masiello
- Division of Neurochemisty, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA.
| | - Mitsuo Saito
- Department of Psychiatry, New York University Langone Medical Center, 550 First Avenue, New York, NY 10016, USA.
- Division of Analytical Psychopharmacology, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA.
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23
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The Developing Microbiome of the Preterm Infant. Clin Ther 2016; 38:733-9. [PMID: 26947798 DOI: 10.1016/j.clinthera.2016.02.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 02/03/2016] [Accepted: 02/03/2016] [Indexed: 12/26/2022]
Abstract
PURPOSE To determine the importance of the neonatal microbiome in intestinal and overall health. METHOD A review of existing literature. FINDINGS AND IMPLICATIONS The microbiome is increasingly understood to have a significant role in health and disease. However, the microbiome of the preterm infant is unique, with simple microbial communities exposed to a consistent diet in a regulated environment, and development from naive to stable under the influence of the neonatal intensive care unit. This early microbiome encounters a still developing host and thus has the potential to program fundamental pathways with implications for neonatal and later outcomes.
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Majidi J, Kosari-Nasab M, Salari AA. Developmental minocycline treatment reverses the effects of neonatal immune activation on anxiety- and depression-like behaviors, hippocampal inflammation, and HPA axis activity in adult mice. Brain Res Bull 2016; 120:1-13. [DOI: 10.1016/j.brainresbull.2015.10.009] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/22/2015] [Accepted: 10/23/2015] [Indexed: 12/13/2022]
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Cardoso FL, Herz J, Fernandes A, Rocha J, Sepodes B, Brito MA, McGavern DB, Brites D. Systemic inflammation in early neonatal mice induces transient and lasting neurodegenerative effects. J Neuroinflammation 2015; 12:82. [PMID: 25924675 PMCID: PMC4440597 DOI: 10.1186/s12974-015-0299-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 04/10/2015] [Indexed: 12/11/2022] Open
Abstract
Background The inflammatory mediator lipopolysaccharide (LPS) has been shown to induce acute gliosis in neonatal mice. However, the progressive effects on the murine neurodevelopmental program over the week that follows systemic inflammation are not known. Thus, we investigated the effects of repeated LPS administration in the first postnatal week in mice, a condition mimicking sepsis in late preterm infants, on the developing central nervous system (CNS). Methods Systemic inflammation was induced by daily intraperitoneal administration (i.p.) of LPS (6 mg/kg) in newborn mice from postnatal day (PND) 4 to PND6. The effects on neurodevelopment were examined by staining the white matter and neurons with Luxol Fast Blue and Cresyl Violet, respectively. The inflammatory response was assessed by quantifying the expression/activity of matrix metalloproteinases (MMP), toll-like receptor (TLR)-4, high mobility group box (HMGB)-1, and autotaxin (ATX). In addition, B6 CX3CR1gfp/+ mice combined with cryo-immunofluorescence were used to determine the acute, delayed, and lasting effects on myelination, microglia, and astrocytes. Results LPS administration led to acute body and brain weight loss as well as overt structural changes in the brain such as cerebellar hypoplasia, neuronal loss/shrinkage, and delayed myelination. The impaired myelination was associated with alterations in the proliferation and differentiation of NG2 progenitor cells early after LPS administration, rather than with excessive phagocytosis by CNS myeloid cells. In addition to disruptions in brain architecture, a robust inflammatory response to LPS was observed. Quantification of inflammatory biomarkers revealed decreased expression of ATX with concurrent increases in HMGB1, TLR-4, and MMP-9 expression levels. Acute astrogliosis (GFAP+ cells) in the brain parenchyma and at the microvasculature interface together with parenchymal microgliosis (CX3CR1+ cells) were also observed. These changes preceded the migration/proliferation of CX3CR1+ cells around the vessels at later time points and the subsequent loss of GFAP+ astrocytes. Conclusion Collectively, our study has uncovered a complex innate inflammatory reaction and associated structural changes in the brains of neonatal mice challenged peripherally with LPS. These findings may explain some of the neurobehavioral abnormalities that develop following neonatal sepsis.
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Affiliation(s)
- Filipa L Cardoso
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal.
| | - Jasmin Herz
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, 10 Center Drive, Bethesda, MD, 20892-1430, USA.
| | - Adelaide Fernandes
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal. .,Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal.
| | - João Rocha
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal.
| | - Bruno Sepodes
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal.
| | - Maria A Brito
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal. .,Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal.
| | - Dorian B McGavern
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, 10 Center Drive, Bethesda, MD, 20892-1430, USA.
| | - Dora Brites
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal. .,Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal.
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Veniaminova EA, Zubareva OE. The changes in exploratory behavior and Fgf2 gene expression in cells of the rat brain after the early postnatal administration of bacterial lipopolysaccharide. NEUROCHEM J+ 2015. [DOI: 10.1134/s1819712415020105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Lajud N, Torner L. Early life stress and hippocampal neurogenesis in the neonate: sexual dimorphism, long term consequences and possible mediators. Front Mol Neurosci 2015; 8:3. [PMID: 25741234 PMCID: PMC4327304 DOI: 10.3389/fnmol.2015.00003] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/15/2015] [Indexed: 01/01/2023] Open
Abstract
Adverse early life experience decreases adult hippocampal neurogenesis and results in increased vulnerability to neuropsychiatric disorders. Despite that the effects of postnatal stress on neurogenesis have been widely studied in adult individuals, few efforts have been done to evaluate its immediate effects on the developing hippocampus. Moreover, it is not clear whether postnatal stress causes a differential impact in hippocampus development in male and female neonates that could be related to emotional deficits in adulthood. It has been proposed that the long term effects of early stress exposure rise from a persistent HPA axis activation during sensitive time windows; nevertheless the exact mechanisms and mediators remain unknown. Here, we summarize the immediate and late effects of early life stress on hippocampal neurogenesis in male and female rat pups, compare its later consequences in emotionality, and highlight some relevant mediator peptides that could be potentially involved in programming.
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Affiliation(s)
- Naima Lajud
- División de Neurociencias, Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social Morelia, Mexico
| | - Luz Torner
- División de Neurociencias, Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social Morelia, Mexico
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Early postnatal respiratory viral infection alters hippocampal neurogenesis, cell fate, and neuron morphology in the neonatal piglet. Brain Behav Immun 2015; 44:82-90. [PMID: 25176574 PMCID: PMC4275372 DOI: 10.1016/j.bbi.2014.08.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 08/18/2014] [Accepted: 08/18/2014] [Indexed: 01/08/2023] Open
Abstract
Respiratory viral infections are common during the neonatal period in humans, but little is known about how early-life infection impacts brain development. The current study used a neonatal piglet model as piglets have a gyrencephalic brain with growth and development similar to human infants. Piglets were inoculated with porcine reproductive and respiratory syndrome virus (PRRSV) to evaluate how chronic neuroinflammation affects hippocampal neurogenesis and neuron morphology. Piglets in the neurogenesis study received one bromodeoxyuridine injection on postnatal day (PD) 7 and then were inoculated with PRRSV. Piglets were sacrificed at PD 28 and the number of BrdU+ cells and cell fate were quantified in the dentate gyrus. PRRSV piglets showed a 24% reduction in the number of newly divided cells forming neurons. Approximately 15% of newly divided cells formed microglia, but this was not affected by sex or PRRSV. Additionally, there was a sexual dimorphism of new cell survival in the dentate gyrus where males had more cells than females, and PRRSV infection caused a decreased survival in males only. Golgi impregnation was used to characterize dentate granule cell morphology. Sholl analysis revealed that PRRSV caused a change in inner granule cell morphology where the first branch point was extended further from the cell body. Males had more complex dendritic arbors than females in the outer granule cell layer, but this was not affected by PRRSV. There were no changes to dendritic spine density or morphology distribution. These findings suggest that early-life viral infection can impact brain development.
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Hoeijmakers L, Lucassen PJ, Korosi A. The interplay of early-life stress, nutrition, and immune activation programs adult hippocampal structure and function. Front Mol Neurosci 2015; 7:103. [PMID: 25620909 PMCID: PMC4288131 DOI: 10.3389/fnmol.2014.00103] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 12/16/2014] [Indexed: 01/08/2023] Open
Abstract
Early-life adversity increases the vulnerability to develop psychopathologies and cognitive decline later in life. This association is supported by clinical and preclinical studies. Remarkably, experiences of stress during this sensitive period, in the form of abuse or neglect but also early malnutrition or an early immune challenge elicit very similar long-term effects on brain structure and function. During early-life, both exogenous factors like nutrition and maternal care, as well as endogenous modulators, including stress hormones and mediator of immunological activity affect brain development. The interplay of these key elements and their underlying molecular mechanisms are not fully understood. We discuss here the hypothesis that exposure to early-life adversity (specifically stress, under/malnutrition and infection) leads to life-long alterations in hippocampal-related cognitive functions, at least partly via changes in hippocampal neurogenesis. We further discuss how these different key elements of the early-life environment interact and affect one another and suggest that it is a synergistic action of these elements that shapes cognition throughout life. Finally, we consider different intervention studies aiming to prevent these early-life adversity induced consequences. The emerging evidence for the intriguing interplay of stress, nutrition, and immune activity in the early-life programming calls for a more in depth understanding of the interaction of these elements and the underlying mechanisms. This knowledge will help to develop intervention strategies that will converge on a more complete set of changes induced by early-life adversity.
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Affiliation(s)
- Lianne Hoeijmakers
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Paul J Lucassen
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Aniko Korosi
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
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Low-grade inflammation disrupts structural plasticity in the human brain. Neuroscience 2014; 275:81-8. [DOI: 10.1016/j.neuroscience.2014.06.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 05/26/2014] [Accepted: 06/03/2014] [Indexed: 01/24/2023]
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Abstract
Microglia, the resident innate immune cells in the brain, have long been understood to be crucial to maintenance in the nervous system, by clearing debris, monitoring for infiltration of infectious agents, and mediating the brain's inflammatory and repair response to traumatic injury, stroke, or neurodegeneration. A wave of new research has shown that microglia are also active players in many basic processes in the healthy brain, including cell proliferation, synaptic connectivity, and physiology. Microglia, both in their capacity as phagocytic cells and via secretion of many neuroactive molecules, including cytokines and growth factors, play a central role in early brain development, including sexual differentiation of the brain. In this review, we present the vast roles microglia play in normal brain development and how perturbations in the normal neuroimmune environment during development may contribute to the etiology of brain-based disorders. There are notable differences between microglia and neuroimmune signaling in the male and female brain throughout the life span, and these differences may contribute to the vast differences in the incidence of neuropsychiatric and neurological disorders between males and females.
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Affiliation(s)
- Kathryn M Lenz
- Department of Psychology and Department of Neuroscience, The Ohio State University, Columbus, OH, USA
| | - Margaret M McCarthy
- Department of Pharmacology and Program in Neuroscience, The University of Maryland School of Medicine, Baltimore, MD, USA
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Modulation of adult hippocampal neurogenesis by early-life environmental challenges triggering immune activation. Neural Plast 2014; 2014:194396. [PMID: 24891958 PMCID: PMC4033517 DOI: 10.1155/2014/194396] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 04/11/2014] [Indexed: 02/03/2023] Open
Abstract
The immune system plays an important role in the communication between the human body and the environment, in early development as well as in adulthood. Per se, research has shown that factors such as maternal stress and nutrition as well as maternal infections can activate the immune system in the infant. A rising number of research studies have shown that activation of the immune system in early life can augment the risk of some psychiatric disorders in adulthood, such as schizophrenia and depression. The mechanisms of such a developmental programming effect are unknown; however some preliminary evidence is emerging in the literature, which suggests that adult hippocampal neurogenesis may be involved. A growing number of studies have shown that pre- and postnatal exposure to an inflammatory stimulus can modulate the number of proliferating and differentiating neural progenitors in the adult hippocampus, and this can have an effect on behaviours of relevance to psychiatric disorders. This review provides a summary of these studies and highlights the evidence supporting a neurogenic hypothesis of immune developmental programming.
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Green HF, Nolan YM. Inflammation and the developing brain: Consequences for hippocampal neurogenesis and behavior. Neurosci Biobehav Rev 2014; 40:20-34. [DOI: 10.1016/j.neubiorev.2014.01.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 01/12/2014] [Accepted: 01/13/2014] [Indexed: 02/06/2023]
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