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Goldim MP, Danielski LG, Rodrigues JF, Joaquim L, Garbossa L, de Oliveira Junior AN, Metzker KLL, Giustina AD, Cardoso T, Barichello T, Petronilho F. Oxidative stress in the choroid plexus contributes to blood–cerebrospinal fluid barrier disruption during sepsis development. Microvasc Res 2019; 123:19-24. [DOI: 10.1016/j.mvr.2018.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 11/07/2018] [Accepted: 12/12/2018] [Indexed: 11/15/2022]
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Rodent Models of Developmental Ischemic Stroke for Translational Research: Strengths and Weaknesses. Neural Plast 2019; 2019:5089321. [PMID: 31093271 PMCID: PMC6476045 DOI: 10.1155/2019/5089321] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 12/19/2018] [Accepted: 02/06/2019] [Indexed: 12/25/2022] Open
Abstract
Cerebral ischemia can occur at any stage in life, but clinical consequences greatly differ depending on the developmental stage of the affected brain structures. Timing of the lesion occurrence seems to be critical, as it strongly interferes with neuronal circuit development and determines the way spontaneous plasticity takes place. Translational stroke research requires the use of animal models as they represent a reliable tool to understand the pathogenic mechanisms underlying the generation, progression, and pathological consequences of a stroke. Moreover, in vivo experiments are instrumental to investigate new therapeutic strategies and the best temporal window of intervention. Differently from adults, very few models of the human developmental stroke have been characterized, and most of them have been established in rodents. The models currently used provide a better understanding of the molecular factors involved in the effects of ischemia; however, they still hold many limitations due to matching developmental stages across different species and the complexity of the human disorder that hardly can be described by segregated variables. In this review, we summarize the key factors contributing to neonatal brain vulnerability to ischemic strokes and we provide an overview of the advantages and limitations of the currently available models to recapitulate different aspects of the human developmental stroke.
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Mallard C, Ek CJ, Vexler ZS. The myth of the immature barrier systems in the developing brain: role in perinatal brain injury. J Physiol 2018. [PMID: 29528501 DOI: 10.1113/jp274938] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Central nervous system homeostasis is maintained by cellular barriers that protect the brain from external environmental changes and protect the CNS from harmful molecules and pathogens in the blood. Historically, for many years these barriers were thought of as immature, with limited functions, during brain development. In this review, we will present advances in the understanding of the barrier systems during development and evidence to show that in fact the barriers serve many important neurodevelopmental functions and that fetal and newborn brains are well protected. We will also discuss how ischaemic injury or systemic inflammation may breach the integrity of the barriers in the developing brain.
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Affiliation(s)
- Carina Mallard
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - C Joakim Ek
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Zinaida S Vexler
- Department of Neurology, University California San Francisco, USA
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Xiang J, Routhe LJ, Wilkinson DA, Hua Y, Moos T, Xi G, Keep RF. The choroid plexus as a site of damage in hemorrhagic and ischemic stroke and its role in responding to injury. Fluids Barriers CNS 2017; 14:8. [PMID: 28351417 PMCID: PMC5371201 DOI: 10.1186/s12987-017-0056-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/08/2017] [Indexed: 12/13/2022] Open
Abstract
While the impact of hemorrhagic and ischemic strokes on the blood–brain barrier has been extensively studied, the impact of these types of stroke on the choroid plexus, site of the blood-CSF barrier, has received much less attention. The purpose of this review is to examine evidence of choroid plexus injury in clinical and preclinical studies of intraventricular hemorrhage, subarachnoid hemorrhage, intracerebral hemorrhage and ischemic stroke. It then discusses evidence that the choroid plexuses are important in the response to brain injury, with potential roles in limiting damage. The overall aim of the review is to highlight deficiencies in our knowledge on the impact of hemorrhagic and ischemic strokes on the choroid plexus, particularly with reference to intraventricular hemorrhage, and to suggest that a greater understanding of the response of the choroid plexus to stroke may open new avenues for brain protection.
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Affiliation(s)
- Jianming Xiang
- Department of Neurosurgery, University of Michigan, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
| | - Lisa J Routhe
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - D Andrew Wilkinson
- Department of Neurosurgery, University of Michigan, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
| | - Ya Hua
- Department of Neurosurgery, University of Michigan, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
| | - Torben Moos
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA. .,Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, USA.
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Kaur C, Rathnasamy G, Ling EA. The Choroid Plexus in Healthy and Diseased Brain. J Neuropathol Exp Neurol 2016; 75:198-213. [DOI: 10.1093/jnen/nlv030] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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CSF Nrf2 and HSPA8 in Parkinson's disease patients with and without LRRK2 gene mutations. J Neural Transm (Vienna) 2015; 123:179-87. [PMID: 26526034 DOI: 10.1007/s00702-015-1479-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 10/23/2015] [Indexed: 10/22/2022]
Abstract
Leucine-rich repeat kinase 2 (LRRK2) gene mutations are the most common genetic cause of Parkinson's disease (PD). CSF specimens from LRRK2 + PD patients and healthy LRRK2 mutation carriers are, therefore, useful for biomarker studies. This study examined the hypothesis that differences are present between subjects with sporadic PD (sPD), PD carriers of LRRK2 mutations (LRRK2 + PD), healthy control subjects lacking LRRK2 mutations (CTL), and LRRK2 mutation-carrying healthy controls (LRRK2 + CTL) for CSF concentrations of six potential PD biomarkers. Two of these proteins, nuclear factor (erythroid-derived 2)-like 2 ("Nrf2") and heat shock 70 kDa protein 8 ("HSPA8"), were detected in preliminary ELISAs, then measured in a larger cohort (60 sPD, 10 LRRK2 + PD, 23 CTL, 31 LRRK2 + CTL). No statistically significant differences were found between the groups (Nrf2 p = 0.13, HSPA8 p = 0.21). Nrf2 concentrations in LRRK2 + PD subjects were strongly positively associated with Unified Parkinson's Disease Rating Scale (UPDRS) total and motor scores [Spearman rho = 0.77 (p = 0.012) and 0.83 (p = 0.005)] and negatively associated with Montreal Cognitive Assessment (MoCA) scores (rho = -0.57; p = 0.11). Partial correlation coefficient calculations indicated that disease duration contributed to the associations of Nrf2 levels with UPDRS scores and with MoCA scores in this group. While CSF Nrf2 and HSPA8 do not appear to offer diagnostic biomarkers for PD, the associations between Nrf2 levels and UPDRS scores in LRRK2 + PD patients merit further investigation.
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Jin C, Londono I, Mallard C, Lodygensky GA. New means to assess neonatal inflammatory brain injury. J Neuroinflammation 2015; 12:180. [PMID: 26407958 PMCID: PMC4583178 DOI: 10.1186/s12974-015-0397-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 09/10/2015] [Indexed: 01/23/2023] Open
Abstract
Preterm infants are especially vulnerable to infection-induced white matter injury, associated with cerebral palsy, cognitive and psychomotor impairment, and other adverse neurological outcomes. The etiology of such lesions is complex and multifactorial. Furthermore, timing and length of exposure to infection also influence neurodevelopmental outcomes. Different mechanisms have been posited to mediate the observed brain injury including microglial activation followed by subsequent release of pro-inflammatory species, glutamate-induced excitotoxicity, and vulnerability of developing oligodendrocytes to cerebral insults. The prevalence of such neurological impairments requires an urgent need for early detection and effective neuroprotective strategies. Accordingly, noninvasive methods of monitoring disease progression and therapy effectiveness are essential. While diagnostic tools using biomarkers from bodily fluids may provide useful information regarding potential risks of developing neurological diseases, the use of magnetic resonance imaging/spectroscopy has emerged as a promising candidate for such purpose. Various pharmacological agents have demonstrated protective effects in the immature brain in animal models; however, few studies have progressed to clinical trials with promising results.
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Affiliation(s)
- Chen Jin
- Department of Pediatrics, Sainte-Justine Hospital and Research Center, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada.
| | - Irene Londono
- Department of Pediatrics, Sainte-Justine Hospital and Research Center, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada.
| | - Carina Mallard
- Perinatal Center, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 405 30, Gothenburg, Sweden.
| | - Gregory A Lodygensky
- Department of Pediatrics, Sainte-Justine Hospital and Research Center, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada. .,Montreal Heart Institute, 5000 Rue Bélanger, Montréal, Québec, Canada. .,Department of Neuroscience and Pharmacology, Université de Montréal, Montréal, Québec, Canada.
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Ek CJ, D'Angelo B, Lehner C, Nathanielsz P, Li C, Mallard C. Expression of tight junction proteins and transporters for xenobiotic metabolism at the blood-CSF barrier during development in the nonhuman primate (P. hamadryas). Reprod Toxicol 2015; 56:32-44. [PMID: 26092209 DOI: 10.1016/j.reprotox.2015.06.047] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 06/04/2015] [Accepted: 06/05/2015] [Indexed: 10/23/2022]
Abstract
The choroid plexus (CP) is rich in barrier mechanisms including transporters and enzymes which can influence drug disposition between blood and brain. We have limited knowledge of their state in fetus. We have studied barrier mechanisms along with metabolism and transporters influencing xenobiotics, using RNAseq and protein analysis, in the CP during the second-half of gestation in a nonhuman primate (Papio hamadryas). There were no differences in the expression of the tight-junctions at the CP suggesting a well-formed fetal blood-CSF barrier during this period of gestation. Further, the fetal CP express many enzymes for phase I-III metabolisms as well as transporters suggesting that it can greatly influence drug disposition and has a significant machinery to deactivate reactive molecules with only minor gestational changes. In summary, the study suggests that from, at least, midgestation, the CP in the nonhuman primate is restrictive and express most known genes associated with barrier function and transport.
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Affiliation(s)
- C Joakim Ek
- Institute for Neuroscience and Physiology, Department of Physiology, Sahlgrenska Academy, University of Gothenburg, 40530 Gothenburg, Sweden.
| | - Barbara D'Angelo
- Institute for Neuroscience and Physiology, Department of Physiology, Sahlgrenska Academy, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Christine Lehner
- Institute of Tendon and Bone Regeneration, Paracelsus Medical University, Spinal Cord Injury and Tissue Regeneration Center Salzburg, Salzburg, Austria; Department of Traumatology and Sports Injuries, Paracelsus Medical University Salzburg, Austria; Austrian Cluster for Tissue Regeneration Vienna, Austria
| | - Peter Nathanielsz
- Wyoming Pregnancy and Life Course Health Center, University of Wyoming, Laramie, WY 82071, United States
| | - Cun Li
- Department of Traumatology and Sports Injuries, Paracelsus Medical University Salzburg, Austria
| | - Carina Mallard
- Institute for Neuroscience and Physiology, Department of Physiology, Sahlgrenska Academy, University of Gothenburg, 40530 Gothenburg, Sweden
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Ek CJ, D'Angelo B, Baburamani AA, Lehner C, Leverin AL, Smith PLP, Nilsson H, Svedin P, Hagberg H, Mallard C. Brain barrier properties and cerebral blood flow in neonatal mice exposed to cerebral hypoxia-ischemia. J Cereb Blood Flow Metab 2015; 35:818-27. [PMID: 25627141 PMCID: PMC4420855 DOI: 10.1038/jcbfm.2014.255] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 12/05/2014] [Accepted: 12/08/2014] [Indexed: 11/09/2022]
Abstract
Insults to the developing brain often result in irreparable damage resulting in long-term deficits in motor and cognitive functions. The only treatment today for hypoxic-ischemic encephalopathy (HIE) in newborns is hypothermia, which has limited clinical benefit. We have studied changes to the blood-brain barriers (BBB) as well as regional cerebral blood flow (rCBF) in a neonatal model of HIE to further understand the underlying pathologic mechanisms. Nine-day old mice pups, brain roughly equivalent to the near-term human fetus, were subjected to hypoxia-ischemia. Hypoxia-ischemia increased BBB permeability to small and large molecules within hours after the insult, which normalized in the following days. The opening of the BBB was associated with changes to BBB protein expression whereas gene transcript levels were increased showing direct molecular damage to the BBB but also suggesting compensatory mechanisms. Brain pathology was closely related to reductions in rCBF during the hypoxia as well as the areas with compromised BBB showing that these are intimately linked. The transient opening of the BBB after the insult is likely to contribute to the pathology but at the same time provides an opportunity for therapeutics to better reach the infarcted areas in the brain.
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Affiliation(s)
- C Joakim Ek
- Department of Physiology, Institute for Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Barbara D'Angelo
- Department of Physiology, Institute for Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ana A Baburamani
- 1] Department of Physiology, Institute for Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden [2] Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK
| | - Christine Lehner
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Department of Traumatology and Sport Injuries, Institute of Tendon and Bone Regeneration, Paracelsus Medical University, Salzburg, Austria; Austrian Cluster for Tissue Regeneration
| | - Anna-Lena Leverin
- Department of Physiology, Institute for Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Peter L P Smith
- Department of Physiology, Institute for Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Holger Nilsson
- Department of Physiology, Institute for Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Pernilla Svedin
- Department of Physiology, Institute for Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Henrik Hagberg
- 1] Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK [2] Departments of Obstetrics and Gynecology, Institute for Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Carina Mallard
- Department of Physiology, Institute for Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Strazielle N, Ghersi-Egea JF. Efflux transporters in blood-brain interfaces of the developing brain. Front Neurosci 2015; 9:21. [PMID: 25698917 PMCID: PMC4318338 DOI: 10.3389/fnins.2015.00021] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 01/13/2015] [Indexed: 01/16/2023] Open
Abstract
The cerebral microvessel endothelium forming the blood-brain barrier (BBB) and the epithelium of the choroid plexuses forming the blood-CSF barrier (BCSFB) operate as gatekeepers for the central nervous system. Exposure of the vulnerable developing brain to chemical insults can have dramatic consequences for brain maturation and lead to life-long neurological diseases. The ability of blood-brain interfaces to efficiently protect the immature brain is therefore an important pathophysiological issue. This is also key to our understanding of drug entry into the brain of neonatal and pediatric patients. Non-specific paracellular diffusion through barriers is restricted early during development, but other neuroprotective properties of these interfaces differ between the developing and adult brains. This review focuses on the developmental expression and function of various classes of efflux transporters. These include the multispecific transporters of the ATP-binding cassette transporter families ABCB, ABCC, ABCG, the organic anion and cation transporters of the solute carrier families SLC21/SLCO and SLC22, and the peptide transporters of the SLC15 family. These transporters play a key role in preventing brain entry of blood-borne molecules such as drugs, environmental toxicants, and endogenous metabolites, or else in increasing the clearance of potentially harmful organic ions from the brain. The limited data available for laboratory animals and human highlight transporter-specific developmental patterns of expression and function, which differ between blood-brain interfaces. The BCSFB achieves an adult phenotype earlier than BBB. Efflux transporters at the BBB appear to be regulated by various factors subsequently secreted by neural progenitors and astrocytes during development. Their expression is also modulated by oxidative stress, inflammation, and exposure to xenobiotic inducers. A better understanding of these regulatory pathways during development, in particular the signaling pathways triggered by oxidative stress and xenobiotics, may open new opportunities to therapeutic manipulation in view to improve or restore neuroprotective functions of the blood-brain interfaces in the context of perinatal injuries.
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Affiliation(s)
- Nathalie Strazielle
- Brain-i Lyon, France ; Oncoflam Team, Lyon Neuroscience Research Center, INSERM, U1028, CNRS, UMR5292, Université Lyon 1 Lyon, France
| | - Jean-François Ghersi-Egea
- Oncoflam Team, Lyon Neuroscience Research Center, INSERM, U1028, CNRS, UMR5292, Université Lyon 1 Lyon, France ; BIP Platform, Lyon Neuroscience Research Center, INSERM, U1028, CNRS, UMR5292, Université Lyon 1 Lyon, France
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11
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Hagberg H, Ek C. Targeting the vasculature for cerebroprotection in the immature brain. Exp Neurol 2014; 261:551-2. [DOI: 10.1016/j.expneurol.2014.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 08/05/2014] [Indexed: 11/29/2022]
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Aliaghaei A, Khodagholi F, Ahmadiani A. Conditioned media of choroid plexus epithelial cells induces Nrf2-activated phase II antioxidant response proteins and suppresses oxidative stress-induced apoptosis in PC12 cells. J Mol Neurosci 2014; 53:617-25. [PMID: 24488602 DOI: 10.1007/s12031-014-0228-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 01/01/2014] [Indexed: 12/01/2022]
Abstract
Based on the critical role of the choroid plexus (CP) in detoxification processes in the central nervous system (CNS), herein we investigated the effect of choroid plexus epithelial cells conditioned media (CPECs-CM) under oxidative conditions. CPECs were isolated from rat brains, cultured, and the conditioned media were collected. Then pheochromocytoma neuron-like cells (PC12) were treated simultaneously with CPECs-CM and H2O2 as the oxidative stressor. Next, the effect of CPECs-CM on neurite outgrowth and cell differentiation in the presence of H2O2 was determined. Our results showed that CPECs-CM improved the expansion of neurites and differentiation in PC12 cells under oxidative stress conditions. Changes in apoptotic factors, nuclear factor erythroid 2-related factor 2 (Nrf2) and γ-glutamylcysteine synthetase as the highlighted pathway in the antioxidant defense system were determined by western blot. Also, the activity of antioxidant enzymes and lipid peroxidation level were determined. CPECs-CM-treated PC12 cells could survive after exposure to H2O2 by reduction of caspase-3 cleavage and Bax level and elevation of anti-apoptotic factor Bcl2. Our data also revealed that Nrf2 activation, and consequently its downstream protein levels, increased in the presence of CPECs-CM. Based on our data, we can conclude that CPECs-CM protects PC12 cells against oxidative stress and apoptosis. It seems that CPECs secrete antioxidative agents and neurotrophic factors that have a role in the health of the CNS.
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Affiliation(s)
- Abbas Aliaghaei
- NeuroBiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Sandberg M, Patil J, D'Angelo B, Weber SG, Mallard C. NRF2-regulation in brain health and disease: implication of cerebral inflammation. Neuropharmacology 2013; 79:298-306. [PMID: 24262633 DOI: 10.1016/j.neuropharm.2013.11.004] [Citation(s) in RCA: 281] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/17/2013] [Accepted: 11/08/2013] [Indexed: 12/13/2022]
Abstract
The nuclear factor erythroid 2 related factor 2 (NRF2) is a key regulator of endogenous inducible defense systems in the body. Under physiological conditions NRF2 is mainly located in the cytoplasm. However, in response to oxidative stress, NRF2 translocates to the nucleus and binds to specific DNA sites termed "anti-oxidant response elements" or "electrophile response elements" to initiate transcription of cytoprotective genes. Acute oxidative stress to the brain, such as stroke and traumatic brain injury is increased in animals that are deficient in NRF2. Insufficient NRF2 activation in humans has been linked to chronic diseases such as Parkinson's disease, Alzheimer's disease and amyotrophic lateral sclerosis. New findings have also linked activation of the NRF2 system to anti-inflammatory effects via interactions with NF-κB. Here we review literature on cellular mechanisms of NRF2 regulation, how to maintain and restore NRF2 function and the relationship between NRF2 regulation and brain damage. We bring forward the hypothesis that inflammation via prolonged activation of key kinases (p38 and GSK-3β) and activation of histone deacetylases gives rise to dysregulation of the NRF2 system in the brain, which contributes to oxidative stress and injury.
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Affiliation(s)
- Mats Sandberg
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Jaspal Patil
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Barbara D'Angelo
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Stephen G Weber
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Carina Mallard
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden.
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Regulation of Toll-like receptors in the choroid plexus in the immature brain after systemic inflammatory stimuli. Transl Stroke Res 2013; 4:220-7. [PMID: 23741282 PMCID: PMC3664758 DOI: 10.1007/s12975-012-0248-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 12/21/2012] [Accepted: 12/25/2012] [Indexed: 12/18/2022]
Abstract
The choroid plexus is the site of the blood–cerebrospinal fluid (CSF) barrier (BCSFB) and has also been considered as a possible route for peripheral immune signals and cells to transfer to the central nervous system. Infection/inflammation stimulates innate and subsequent adaptive immune responses via Toll-like receptors (TLRs). In this study, we have investigated the mRNA expression of TLRs, cytokines, and tight junction proteins in the choroid plexus in the immature brain after systemic inflammation, as well as accumulation of immune cells into the CSF. Specific ligands for TLR-1/2, TLR-3, and TLR-4 were administered to postnatal day 8 mice and mRNA expression for the targeted genes was examined in the choroid plexus. We found that mRNA for all four TLRs was detected in the choroid plexus under control conditions. Following immune stimulation, expression of all the TLRs was upregulated by their respective ligands, except for TLR-4 mRNA, which was downregulated by Pam3CSK4 (PAM; a TLR-1/2 ligand). In addition, we investigated BCSFB regulation after TLR stimulation and found that TLR-1/2 and TLR-4 activation was associated with changes in mRNA expression of the tight junction protein occludin in the choroid plexus. PAM induced choroid plexus transcription of TNF-α and resulted in the most dramatic increase in numbers of white blood cells in the CSF. The data suggest a possible mechanism whereby systemic inflammation stimulates TLRs in the choroid plexus, which may lead to disturbances in choroid plexus barrier function, as well as infiltration of immune cells through the plexus.
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