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Ophelders DR, Gussenhoven R, Klein L, Jellema RK, Westerlaken RJ, Hütten MC, Vermeulen J, Wassink G, Gunn AJ, Wolfs TG. Preterm Brain Injury, Antenatal Triggers, and Therapeutics: Timing Is Key. Cells 2020; 9:E1871. [PMID: 32785181 PMCID: PMC7464163 DOI: 10.3390/cells9081871] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/31/2020] [Accepted: 08/05/2020] [Indexed: 02/08/2023] Open
Abstract
With a worldwide incidence of 15 million cases, preterm birth is a major contributor to neonatal mortality and morbidity, and concomitant social and economic burden Preterm infants are predisposed to life-long neurological disorders due to the immaturity of the brain. The risks are inversely proportional to maturity at birth. In the majority of extremely preterm infants (<28 weeks' gestation), perinatal brain injury is associated with exposure to multiple inflammatory perinatal triggers that include antenatal infection (i.e., chorioamnionitis), hypoxia-ischemia, and various postnatal injurious triggers (i.e., oxidative stress, sepsis, mechanical ventilation, hemodynamic instability). These perinatal insults cause a self-perpetuating cascade of peripheral and cerebral inflammation that plays a critical role in the etiology of diffuse white and grey matter injuries that underlies a spectrum of connectivity deficits in survivors from extremely preterm birth. This review focuses on chorioamnionitis and hypoxia-ischemia, which are two important antenatal risk factors for preterm brain injury, and highlights the latest insights on its pathophysiology, potential treatment, and future perspectives to narrow the translational gap between preclinical research and clinical applications.
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Affiliation(s)
- Daan R.M.G. Ophelders
- Department of Pediatrics, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (D.R.M.G.O.); (R.G.); (L.K.); (R.K.J.); (R.J.J.W.); (M.C.H.)
- School for Oncology and Developmental Biology (GROW), Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Ruth Gussenhoven
- Department of Pediatrics, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (D.R.M.G.O.); (R.G.); (L.K.); (R.K.J.); (R.J.J.W.); (M.C.H.)
| | - Luise Klein
- Department of Pediatrics, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (D.R.M.G.O.); (R.G.); (L.K.); (R.K.J.); (R.J.J.W.); (M.C.H.)
- School for Mental Health and Neuroscience (MHeNS), Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Reint K. Jellema
- Department of Pediatrics, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (D.R.M.G.O.); (R.G.); (L.K.); (R.K.J.); (R.J.J.W.); (M.C.H.)
| | - Rob J.J. Westerlaken
- Department of Pediatrics, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (D.R.M.G.O.); (R.G.); (L.K.); (R.K.J.); (R.J.J.W.); (M.C.H.)
- School for Oncology and Developmental Biology (GROW), Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Matthias C. Hütten
- Department of Pediatrics, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (D.R.M.G.O.); (R.G.); (L.K.); (R.K.J.); (R.J.J.W.); (M.C.H.)
- School for Oncology and Developmental Biology (GROW), Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Jeroen Vermeulen
- Department of Pediatric Neurology, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands;
| | - Guido Wassink
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Private bag 92019, Auckland 1023, New Zealand; (G.W.); (A.J.G.)
| | - Alistair J. Gunn
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Private bag 92019, Auckland 1023, New Zealand; (G.W.); (A.J.G.)
| | - Tim G.A.M. Wolfs
- Department of Pediatrics, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands; (D.R.M.G.O.); (R.G.); (L.K.); (R.K.J.); (R.J.J.W.); (M.C.H.)
- School for Oncology and Developmental Biology (GROW), Maastricht University, 6229 ER Maastricht, The Netherlands
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DISDIER C, STONESTREET BS. Hypoxic-ischemic-related cerebrovascular changes and potential therapeutic strategies in the neonatal brain. J Neurosci Res 2020; 98:1468-1484. [PMID: 32060970 PMCID: PMC7242133 DOI: 10.1002/jnr.24590] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 01/20/2020] [Accepted: 01/28/2020] [Indexed: 12/11/2022]
Abstract
Perinatal hypoxic-ischemic (HI)-related brain injury is an important cause of morbidity and long-standing disability in newborns. The only currently approved therapeutic strategy available to reduce brain injury in the newborn is hypothermia. Therapeutic hypothermia can only be used to treat HI encephalopathy in full-term infants and survivors remain at high risk for a wide spectrum of neurodevelopmental abnormalities as a result of residual brain injury. Therefore, there is an urgent need for adjunctive therapeutic strategies. Inflammation and neurovascular damage are important factors that contribute to the pathophysiology of HI-related brain injury and represent exciting potential targets for therapeutic intervention. In this review, we address the role of each component of the neurovascular unit (NVU) in the pathophysiology of HI-related injury in the neonatal brain. Disruption of the blood-brain barrier (BBB) observed in the early hours after an HI-related event is associated with a response at the basal lamina level, which comprises astrocytes, pericytes, and immune cells, all of which could affect BBB function to further exacerbate parenchymal injury. Future research is required to determine potential drugs that could prevent or attenuate neurovascular damage and/or augment repair. However, some studies have reported beneficial effects of hypothermia, erythropoietin, stem cell therapy, anti-cytokine therapy and metformin in ameliorating several different facets of damage to the NVU after HI-related brain injury in the perinatal period.
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Affiliation(s)
- Clémence DISDIER
- Department of Pediatrics, Women & Infants Hospital of Rhode Island, The Alpert Medical School of Brown University, Providence, RI 02905, USA
| | - Barbara S STONESTREET
- Department of Pediatrics, Women & Infants Hospital of Rhode Island, The Alpert Medical School of Brown University, Providence, RI 02905, USA
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Bell AH, Miller SL, Castillo-Melendez M, Malhotra A. The Neurovascular Unit: Effects of Brain Insults During the Perinatal Period. Front Neurosci 2020; 13:1452. [PMID: 32038147 PMCID: PMC6987380 DOI: 10.3389/fnins.2019.01452] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 12/30/2019] [Indexed: 12/31/2022] Open
Abstract
The neurovascular unit (NVU) is a relatively recent concept in neuroscience that broadly describes the relationship between brain cells and their blood vessels. The NVU incorporates cellular and extracellular components involved in regulating cerebral blood flow and blood-brain barrier function. The NVU within the adult brain has attracted strong research interest and its structure and function is well described, however, the NVU in the developing brain over the fetal and neonatal period remains much less well known. One area of particular interest in perinatal brain development is the impact of known neuropathological insults on the NVU. The aim of this review is to synthesize existing literature to describe structure and function of the NVU in the developing brain, with a particular emphasis on exploring the effects of perinatal insults. Accordingly, a brief overview of NVU components and function is provided, before discussion of NVU development and how this may be affected by perinatal pathologies. We have focused this discussion around three common perinatal insults: prematurity, acute hypoxia, and chronic hypoxia. A greater understanding of processes affecting the NVU in the perinatal period may enable application of targeted therapies, as well as providing a useful basis for research as it expands further into this area.
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Affiliation(s)
- Alexander H. Bell
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Suzanne L. Miller
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Margie Castillo-Melendez
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Atul Malhotra
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Monash Newborn, Monash Children’s Hospital, Melbourne, VIC, Australia
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Sun M, Shinoda Y, Fukunaga K. KY-226 Protects Blood-brain Barrier Function Through the Akt/FoxO1 Signaling Pathway in Brain Ischemia. Neuroscience 2018; 399:89-102. [PMID: 30579831 DOI: 10.1016/j.neuroscience.2018.12.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 12/12/2018] [Accepted: 12/16/2018] [Indexed: 01/05/2023]
Abstract
KY-226 is a protein tyrosine phosphatase 1B (PTP1B) inhibitor that protects neurons from cerebral ischemic injury. KY-226 restores Akt (protein kinase B) phosphorylation and extracellular signal-regulated kinase (ERK) reduction in transient middle cerebral artery occlusion (tMCAO) damage. However, the mechanisms underlying the neuroprotective effects of KY-226 are unclear. To address this, the effects of KY-226 on blood-brain barrier (BBB) dysfunction were examined in tMCAO mice. KY-226 (10 mg/kg, i.p.) was administered to ICR mice 30 min after 2 h of tMCAO. To assess Akt or ERK involvement, wortmannin (i.c.v.) or U0126 (i.v.), selective inhibitors of PI3K and ERK, respectively, were administered to mice 30 min before ischemia. BBB integrity was assessed by Evans blue leakage 24 h post-reperfusion. The levels of tight junction (TJ) proteins, ZO-1 and occludin, were measured by western blotting; ZO-1 mRNA level was measured by RT-PCR. Compared to vehicle, KY-226 treatment prevented BBB breakdown and reduction in TJ protein levels. KY-226 treatment restored ZO-1 mRNA levels post-reperfusion. Pre-administration of wortmannin or U0126 blocked the protective effects of KY-226 on ZO-1 protein and mRNA reduction in tMCAO mice. In bEnd.3 cells, lipopolysaccharide treatment reduced mRNA and protein levels of ZO-1, an effect rescued by KY-226 treatment. Further, KY-226 treatment restored phosphorylation of pAkt (T308) and its downstream target forkhead box protein O1 (FoxO1) (S256) in bEnd.3 cells. Collectively, we demonstrate that KY-226 protects BBB integrity by restoration of TJ proteins, an effect partly mediated by Akt/FoxO1 pathway activation. Thus, protection of BBB integrity likely underlies KY-226-induced neuroprotection in tMCAO mice.
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Affiliation(s)
- Meiling Sun
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Japan
| | - Yasuharu Shinoda
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Japan
| | - Kohji Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Japan.
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Lai JCY, Rocha-Ferreira E, Ek CJ, Wang X, Hagberg H, Mallard C. Immune responses in perinatal brain injury. Brain Behav Immun 2017; 63:210-223. [PMID: 27865947 DOI: 10.1016/j.bbi.2016.10.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 10/28/2016] [Accepted: 10/30/2016] [Indexed: 12/13/2022] Open
Abstract
The perinatal period has often been described as immune deficient. However, it has become clear that immune responses in the neonate following exposure to microbes or as a result of tissue injury may be substantial and play a role in perinatal brain injury. In this article we will review the immune cell composition under normal physiological conditions in the perinatal period, both in the human and rodent. We will summarize evidence of the inflammatory responses to stimuli and discuss how neonatal immune activation, both in the central nervous system and in the periphery, may contribute to perinatal hypoxic-ischemic brain injury.
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Affiliation(s)
- Jacqueline C Y Lai
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden
| | - Eridan Rocha-Ferreira
- Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden
| | - C Joakim Ek
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden
| | - Xiaoyang Wang
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden
| | - Henrik Hagberg
- Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden
| | - Carina Mallard
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden.
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Spasova MS, Chen X, Sadowska GB, Horton ER, Lim YP, Stonestreet BS. Ischemia reduces inter-alpha inhibitor proteins in the brain of the ovine fetus. Dev Neurobiol 2016; 77:726-737. [PMID: 27618403 DOI: 10.1002/dneu.22451] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 09/02/2016] [Accepted: 09/08/2016] [Indexed: 01/04/2023]
Abstract
Hypoxic-ischemic (HI) brain injury is a major cause of neurological abnormalities in the perinatal period. Inflammation contributes to the evolution of HI brain injury. Inter-alpha inhibitor proteins (IAIPs) are a family of proteins that are part of the innate immune system. We have reported that endogenous IAIPs exhibit developmental changes in ovine brain and that exogenous IAIP treatment reduces neuronal death in HI neonatal rats. However, the effects of HI on endogenous IAIPs in brain have not been previously examined. In this study, we examined the effects of ischemia-reperfusion on endogenous IAIPs levels in fetal sheep brain. Cerebral cortex, cerebellum, cervical spinal cord, choroid plexus, and CSF were snap frozen from sham control fetuses at 127 days gestation and after 30-min of carotid occlusion and 4-, 24-, and 48-h of reperfusion. IAIP levels were determined by Western immunoblot. IAIP expressions of the 250 kDa Inter-alpha inhibitor (IaI) and 125 kDa Pre-alpha inhibitor (PaI) in cerebral cortex and PaI in cerebellum were reduced (p < 0.05) 4-h after ischemia compared with controls and returned toward control levels 24- and 48-h after ischemia. CSF PaI and IaI were reduced 48 h after ischemia. We conclude that IAIPs in cerebral cortex and cerebellum are reduced by brain ischemia, and return toward control levels between 24 and 48 h after ischemia. However, changes in CSF IAIPs were delayed, exhibiting decreases 48 h after ischemia. We speculate that the decreases in endogenous IAIPs reflect increased utilization, potentially suggesting that they have endogenous neuroprotective properties. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 726-737, 2017.
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Affiliation(s)
- Mariya S Spasova
- Department of Pediatrics, the Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI, 02905
| | - Xiaodi Chen
- Department of Pediatrics, the Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI, 02905
| | - Grazyna B Sadowska
- Department of Pediatrics, the Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI, 02905
| | - Edward R Horton
- Department of Pediatrics, the Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI, 02905
| | - Yow-Pin Lim
- ProThera Biologics, Inc, Providence, RI, 02903
| | - Barbara S Stonestreet
- Department of Pediatrics, the Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI, 02905
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Sadowska GB, Ahmedli N, Chen X, Stonestreet BS. Ontogeny of tight junction protein expression in the ovine cerebral cortex during development. Neuroscience 2015; 310:422-9. [PMID: 26424381 DOI: 10.1016/j.neuroscience.2015.09.062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/22/2015] [Accepted: 09/23/2015] [Indexed: 11/30/2022]
Abstract
Tight junctions of the blood-brain barrier are composed of transmembrane and associated cytoplasmic proteins. The transmembrane claudin proteins form the primary seal between endothelial cells and junctional adhesion molecules (JAMs) regulate tight junction formation. We have previously shown that claudin-1, claudin-5, zonula occludens (ZO)-1, and ZO-2 exhibit differential developmental regulation from 60% of gestation up to maturity in adult sheep. The purpose of the current study was to examine developmental changes in claudin-3, -12, and JAM-A protein expression in cerebral cortices of fetuses at 60%, 80%, and 90% gestation, and in newborn and adult sheep. We also examined correlations between changes in endogenous cortisol levels and tight junction protein expression in cerebral cortices of the fetuses. Claudin-3, -12 and JAM-A expressions were determined by Western immunoblot. Claudin-3 and -12 were lower (P<0.01) at 60%, 80%, 90% and in newborns than in adults, and JAM-A was lower in adults than in fetuses at 80% and 90% gestation. Claudin-3 expression demonstrated a direct correlation with increasing plasma cortisol levels (r=0.60, n=15, P<0.02) in the fetuses. We conclude that: claudin-3, -12 and JAM-A are expressed as early as 60% of gestation in ovine cerebral cortices, exhibit differential developmental regulation, and that increasing endogenous glucocorticoids modulate claudin-3 expression in the fetus.
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Affiliation(s)
- G B Sadowska
- Department of Pediatrics, The Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI 02905, United States
| | - N Ahmedli
- Department of Pediatrics, The Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI 02905, United States
| | - X Chen
- Department of Pediatrics, The Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI 02905, United States
| | - B S Stonestreet
- Department of Pediatrics, The Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI 02905, United States.
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Spasova MS, Sadowska GB, Threlkeld SW, Lim YP, Stonestreet BS. Ontogeny of inter-alpha inhibitor proteins in ovine brain and somatic tissues. Exp Biol Med (Maywood) 2015; 239:724-36. [PMID: 24728724 DOI: 10.1177/1535370213519195] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Inter-alpha inhibitor proteins (IAIPs) found in relatively high concentrations in human plasma are important in inflammation. IAIPs attenuate brain damage in young and adult subjects, decrease during sepsis and necrotizing enterocolitis in premature infants, and attenuate sepsis-related inflammation in newborn rats. Although a few studies have reported adult organ-specific IAIP expression, information is not available on age-dependent IAIP expression. Given evidence suggesting IAIPs attenuate brain damage in young and adult subjects, and inflammation in newborns, we examined IAIP expression in plasma, cerebral cortex (CC), choroid plexus (CP), cerebral spinal fluid (CSF), and somatic organs in fetal, newborn, and adult sheep to determine the endogenous expression patterns of these proteins during development. IAIPs (enzyme-linked immunosorbent assay) were higher in newborn and adult than fetal plasma (P < 0.05). Western immunoblot detected 125 kDa PaI (Pre-alpha Inhibitor) and 250 kDa IaI (Inter-alpha Inhibitor) in plasma, CNS, and somatic organs. PaI expression in CC and CP was higher in fetuses than newborns and adults, but IaI expression was higher in adults than fetuses and newborns. Both PaI and IaI were higher in fetal than newborn CSF. IAIPs exhibited organ-specific ontogenic patterns in placenta, liver, heart, and kidney. These results provide evidence for the first time that plasma, brain, placenta, liver, heart, and kidney express IAIPs throughout ovine development and that expression patterns are unique to each organ. Although exact functions of IAIPs in CNS and somatic tissues are not known, their presence in relatively high amounts during development suggests their potential importance in brain and organ development.
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Zhang J, Sadowska GB, Chen X, Park SY, Kim JE, Bodge CA, Cummings E, Lim YP, Makeyev O, Besio WG, Gaitanis J, Banks WA, Stonestreet BS. Anti-IL-6 neutralizing antibody modulates blood-brain barrier function in the ovine fetus. FASEB J 2015; 29:1739-53. [PMID: 25609424 DOI: 10.1096/fj.14-258822] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 12/22/2014] [Indexed: 12/15/2022]
Abstract
Impaired blood-brain barrier function represents an important component of hypoxic-ischemic brain injury in the perinatal period. Proinflammatory cytokines could contribute to ischemia-related blood-brain barrier dysfunction. IL-6 increases vascular endothelial cell monolayer permeability in vitro. However, contributions of IL-6 to blood-brain barrier abnormalities have not been examined in the immature brain in vivo. We generated pharmacologic quantities of ovine-specific neutralizing anti-IL-6 mAbs and systemically infused mAbs into fetal sheep at 126 days of gestation after exposure to brain ischemia. Anti-IL-6 mAbs were measured by ELISA in fetal plasma, cerebral cortex, and cerebrospinal fluid, blood-brain barrier permeability was quantified using the blood-to-brain transfer constant in brain regions, and IL-6, tight junction proteins, and plasmalemma vesicle protein (PLVAP) were detected by Western immunoblot. Anti-IL-6 mAb infusions resulted in increases in mAb (P < 0.05) in plasma, brain parenchyma, and cerebrospinal fluid and decreases in brain IL-6 protein. Twenty-four hours after ischemia, anti-IL-6 mAb infusions attenuated ischemia-related increases in blood-brain barrier permeability and modulated tight junction and PLVAP protein expression in fetal brain. We conclude that inhibiting the effects of IL-6 protein with systemic infusions of neutralizing antibodies attenuates ischemia-related increases in blood-brain barrier permeability by inhibiting IL-6 and modulates tight junction proteins after ischemia.
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Affiliation(s)
- Jiyong Zhang
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Grazyna B Sadowska
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Xiaodi Chen
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Seon Yeong Park
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Jeong-Eun Kim
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Courtney A Bodge
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Erin Cummings
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Yow-Pin Lim
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Oleksandr Makeyev
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Walter G Besio
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - John Gaitanis
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - William A Banks
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Barbara S Stonestreet
- *Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, USA; ProThera Biologics, Incorporated, Providence, Rhode Island, USA; Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island, USA; Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA; and Geriatric Research Educational, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
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10
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Abstract
Therapeutic hypothermia is the only treatment that has been shown to be of benefit to infant's ≥ 36 weeks of gestation with hypoxic-ischemic encephalopathy. The evidence for the benefit is based on multiple, well-designed randomized clinical trials. Based on this data, the use of therapeutic hypothermia has been widely disseminated throughout the neonatal community. An important concept in hypoxic-ischemic brain injury is the functioning of the neurovascular unit which links neurons, non-neuronal cellular elements and the capillary endothelial cells to promote optimal barrier maintenance between the brain and systemic circulation, regulation of blood flow and neuro-immunologic functioning. Hypoxic-ischemic injury can trigger increased permeability of the blood-brain-barrier via molecular events within the neurovascular unit and initiate pathways to brain injury. In addition, exposure of the brain to cellular elements from the systemic circulation can further propagate the neuro-inflammatory response. The influence of temperature on injury to the neurovascular unit has received relatively little attention. This review will focus on one component of the neurovascular unit, the blood-brain barrier and its constituents. Specifically, this review will address the effects of hypoxia-ischemia and temperature on the neurovascular unit and potential knowledge gaps which may serve as areas for further investigation.
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Affiliation(s)
- Abbot Laptook
- Warren Alpert Medical School of Brown University, United States; Neonatal Intensive Care Unit, Women and Infants Hospital of Rhode Island, 101 Dudley Street, Providence, RI 02905, United States.
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11
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Maternal treatment with glucocorticoids modulates gap junction protein expression in the ovine fetal brain. Neuroscience 2014; 275:248-58. [PMID: 24929069 DOI: 10.1016/j.neuroscience.2014.05.066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Revised: 04/28/2014] [Accepted: 05/14/2014] [Indexed: 12/31/2022]
Abstract
Gap junctions facilitate intercellular communication and are important in brain development. Connexins (Cx) comprise a transmembrane protein family that forms gap junctions. Cx-32 is expressed in oligodendrocytes and neurons, Cx-36 in neurons, and Cx-43 in astrocytes. Although single antenatal steroid courses are recommended for fetal lung maturation, multiple courses can be given to women at recurrent risk for premature delivery. We examined the effects of single and multiple glucocorticoid courses on Cx-32, Cx-36, and Cx-43 protein expressions in the fetal cerebral cortex, cerebellum, and spinal cord, and differences in Cx expression among brain regions under basal conditions. In the single-course groups, the ewes received dexamethasone (6 mg) or placebo as four intramuscular injections every 12h over 48 h. In the multiple-course groups, the ewes received the same treatment, once a week for 5 weeks starting at 76-78 days of gestation. Cx were measured by Western immunoblot on brain samples from 105 to 108-day gestation fetuses. A single dexamethasone course was associated with increases (P<0.05) in cerebral cortical and spinal cord Cx-36 and Cx-43 and multiple courses with increases in cerebellar and spinal cord Cx-36, and cerebral cortical and cerebellar Cx-43. Cx-32 did not change. Cx-32 was higher in the cerebellum than cerebral cortex and spinal cord, Cx-36 higher in the spinal cord than cerebellum, and Cx-43 higher in the cerebellum and spinal cord than cerebral cortex during basal conditions. In conclusion, maternal glucocorticoid therapy increases specific Cx, responses to different maternal courses vary among Cx and brain regions, and Cx expression differs among brain regions under basal conditions. Maternal treatment with glucocorticoids differentially modulates Cx in the fetal brain.
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12
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Baburamani AA, Ek CJ, Walker DW, Castillo-Melendez M. Vulnerability of the developing brain to hypoxic-ischemic damage: contribution of the cerebral vasculature to injury and repair? Front Physiol 2012; 3:424. [PMID: 23162470 PMCID: PMC3493883 DOI: 10.3389/fphys.2012.00424] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/17/2012] [Indexed: 11/13/2022] Open
Abstract
As clinicians attempt to understand the underlying reasons for the vulnerability of different regions of the developing brain to injury, it is apparent that little is known as to how hypoxia-ischemia may affect the cerebrovasculature in the developing infant. Most of the research investigating the pathogenesis of perinatal brain injury following hypoxia-ischemia has focused on excitotoxicity, oxidative stress and an inflammatory response, with the response of the developing cerebrovasculature receiving less attention. This is surprising as the presentation of devastating and permanent injury such as germinal matrix-intraventricular haemorrhage (GM-IVH) and perinatal stroke are of vascular origin, and the origin of periventricular leukomalacia (PVL) may also arise from poor perfusion of the white matter. This highlights that cerebrovasculature injury following hypoxia could primarily be responsible for the injury seen in the brain of many infants diagnosed with hypoxic-ischemic encephalopathy (HIE). Interestingly the highly dynamic nature of the cerebral blood vessels in the fetus, and the fluctuations of cerebral blood flow and metabolic demand that occur following hypoxia suggest that the response of blood vessels could explain both regional protection and vulnerability in the developing brain. However, research into how blood vessels respond following hypoxia-ischemia have mostly been conducted in adult models of ischemia or stroke, further highlighting the need to investigate how the developing cerebrovasculature responds and the possible contribution to perinatal brain injury following hypoxia. This review discusses the current concepts on the pathogenesis of perinatal brain injury, the development of the fetal cerebrovasculature and the blood brain barrier (BBB), and key mediators involved with the response of cerebral blood vessels to hypoxia.
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Affiliation(s)
- Ana A Baburamani
- The Ritchie Centre, Monash Medical Centre, Monash Institute of Medical Research, Clayton Melbourne, VIC, Australia ; Sahlgrenska Academy, Gothenburg University Göteborg, Sweden
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13
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Chen X, Threlkeld SW, Cummings EE, Juan I, Makeyev O, Besio WG, Gaitanis J, Banks WA, Sadowska GB, Stonestreet BS. Ischemia-reperfusion impairs blood-brain barrier function and alters tight junction protein expression in the ovine fetus. Neuroscience 2012; 226:89-100. [PMID: 22986172 DOI: 10.1016/j.neuroscience.2012.08.043] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 08/14/2012] [Accepted: 08/19/2012] [Indexed: 10/27/2022]
Abstract
The blood-brain barrier is a restrictive interface between the brain parenchyma and the intravascular compartment. Tight junctions contribute to the integrity of the blood-brain barrier. Hypoxic-ischemic damage to the blood-brain barrier could be an important component of fetal brain injury. We hypothesized that increases in blood-brain barrier permeability after ischemia depend upon the duration of reperfusion and that decreases in tight junction proteins are associated with the ischemia-related impairment in blood-brain barrier function in the fetus. Blood-brain barrier function was quantified with the blood-to-brain transfer constant (K(i)) and tight junction proteins by Western immunoblot in fetal sheep at 127 days of gestation without ischemia, and 4, 24, or 48 h after ischemia. The largest increase in K(i) (P<0.05) was 4 h after ischemia. Occludin and claudin-5 expressions decreased at 4 h, but returned toward control levels 24 and 48 h after ischemia. Zonula occludens-1 and -2 decreased after ischemia. Inverse correlations between K(i) and tight junction proteins suggest that the decreases in tight junction proteins contribute to impaired blood-brain barrier function after ischemia. We conclude that impaired blood-brain barrier function is an important component of hypoxic-ischemic brain injury in the fetus, and that increases in quantitatively measured barrier permeability (K(i)) change as a function of the duration of reperfusion after ischemia. The largest increase in permeability occurs 4 h after ischemia and blood-brain barrier function improves early after injury because the blood-brain barrier is less permeable 24 and 48 than 4 h after ischemia. Changes in the tight junction molecular composition are associated with increases in blood-brain barrier permeability after ischemia.
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Affiliation(s)
- X Chen
- Department of Pediatrics, The Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, Providence, RI 02905, USA
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14
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Sadowska GB, Threlkeld SW, Flangini A, Sharma S, Stonestreet BS. Ontogeny and the effects of in utero brain ischemia on interleukin-1β and interleukin-6 protein expression in ovine cerebral cortex and white matter. Int J Dev Neurosci 2012; 30:457-63. [PMID: 22698958 DOI: 10.1016/j.ijdevneu.2012.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 06/04/2012] [Accepted: 06/04/2012] [Indexed: 11/19/2022] Open
Abstract
Interleukin (IL)-1β and IL-6 have been implicated in brain development, injury progression, and fetal/maternal immune interactions. We examined IL-1β and IL-6 protein expression in cerebral cortex (CC) and white matter (WM) from non-ischemic ovine fetuses at 87-90, 122-127, and 135-137 days of gestation, pregnant ewes at 87-90 and 135-137 days of gestation, and fetuses exposed to 48 or 72h of reperfusion after ischemia. Protein expression was determined by Western immunoblot. In non-ischemic CC, IL-1β was higher (P<0.05) in adult sheep and fetuses at 135-137 than 87-90 and 122-127 days, and IL-6 higher at 122-127 than 87-90 days, and in adults than fetuses at 87-90, 122-127, and 135-137 days of gestation. In non-ischemic fetal WM, IL-6 was higher at 135-137 than 87-90 days, but IL-1β did not differ. In CC, IL-1β was higher in ewes at 135-137 than 87-90 days and IL-6 at 135-137 days and in non-pregnant adults than ewes at 87-90 days of gestation. In WM, IL-1β was higher in ewes at 135-137 than 87-90 days of gestation, but IL-6 did not differ. Forty-eight and 72h after ischemia, CC IL-1β was higher than in non-ischemic fetuses. Seventy-two hours after ischemia, IL-1β and IL-6 were higher in WM than CC. In conclusion, IL-1β and IL-6 exhibit developmental regulation in fetal brain, change during gestation in brains of pregnant ewes, show regional differences in normal brains of fetuses and ewes, demonstrate differential responses after ischemia in CC and WM, and IL-1β but not IL-6 increases after ischemia in CC.
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Affiliation(s)
- Grazyna B Sadowska
- Department of Pediatrics, Women & Infants Hospital of Rhode Island, The Alpert Medical School of Brown University, 101 Dudley Street, Providence, RI 02905, USA
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15
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Lagaraine C, Skipor J, Szczepkowska A, Dufourny L, Thiery JC. Tight junction proteins vary in the choroid plexus of ewes according to photoperiod. Brain Res 2011; 1393:44-51. [PMID: 21529785 DOI: 10.1016/j.brainres.2011.04.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 03/07/2011] [Accepted: 04/02/2011] [Indexed: 10/18/2022]
Abstract
Sheep from temperate latitudes exhibit seasonal variations in many physiological functions such as reproduction, food intake, body weight, and pelage growth. Majority of seasonal changes are controlled by the annual photoperiodic cycle and melatonin secretion. For reproduction, the resulting key event is a modulation of the negative feedback of steroids on gonadotropin secretion. However, this seasonal effect could also depend on variable uptake of steroids by the brain. Seasonal regulation of food intake also involves numerous peripheral hormones, among which the protein hormone leptin informs the brain on the metabolic status of the animal. It has been shown previously that access of progesterone, estradiol and leptin to the cerebrospinal fluid (CSF) increases under long days. This physiological modulation of the passage of hormones to the brain could depend on regulation of the permeability of the blood-CSF barrier. This study therefore compared the tight junction proteins in the choroid plexus of ewes exposed to short days or long days. Levels of occludin, zonula occludens proteins (ZO) ZO-1 and ZO-2, afadin and cadherin were significantly higher during short days, but no statistical difference was observed for junctional adhesion molecule 1 (JAM-1), ZO-3 or claudins 1 and 5. These results are consistent with an increase in the blood-CSF barrier permeability during long days through a regulation of tight junctions and show that the permeability could depend upon physiological conditions such as photoperiodic status.
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Affiliation(s)
- Christine Lagaraine
- INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France
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16
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Sadowska GB, Malaeb SN, Stonestreet BS. Maternal glucocorticoid exposure alters tight junction protein expression in the brain of fetal sheep. Am J Physiol Heart Circ Physiol 2009; 298:H179-88. [PMID: 19855054 DOI: 10.1152/ajpheart.00828.2009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We examined the expression of tight junction (TJ) proteins in the cerebral cortex, cerebellum, and spinal cord of fetuses after maternal treatment with single and multiple courses of dexamethasone. Ewes received either single courses of four 6-mg dexamethasone or placebo injections every 12 h for 48 h between 104 and 107 days or the same treatment once a week between 76-78 and 104-107 days of gestation. TJ protein expression was determined by Western immunoblot analysis on tissue harvested at 105-108 days of gestation. Blood-brain barrier permeability has been previously quantified with the blood-to-brain transfer constant (K(i)) with alpha-aminoisobutyric acid (39). After a single course of dexamethasone, claudin-5 increased (P < 0.05) in the cerebral cortex, occludin and claudin-1 increased in the cerebellum, and occludin increased in the spinal cord. After multiple dexamethasone courses, occludin and zonula occludens (ZO)-1 increased in the cerebral cortex, and occludin and claudin-1 increased in the cerebellum. Junctional adhesion molecule-A and ZO-2 expressions did not change. Linear regression comparing K(i) to TJ proteins showed inverse correlations with claudin-1 and claudin-5 in the cerebral cortex after a single course and ZO-2 in the spinal cord after multiple courses and direct correlations with ZO-1 in the cerebellum and spinal cord after multiple courses. We conclude that maternal glucocorticoid treatment increases the expression of specific TJ proteins in vivo, patterns of TJ protein expression vary after exposure to single and multiple glucocorticoid courses, and decreases in blood-brain barrier permeability are associated with increases in claudin-1, claudin-5, and ZO-2 expression and decreases in ZO-1 expression. In utero glucocorticoid exposure alters the molecular composition of the barrier and affects fetal blood-brain barrier function.
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Affiliation(s)
- Grazyna B Sadowska
- The Warren Alpert Medical School of Brown University, Department of Pediatrics, Women and Infants' Hospital of Rhode Island, Providence, RI 02905-2499, USA
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17
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Duncan AR, Sadowska GB, Stonestreet BS. Ontogeny and the effects of exogenous and endogenous glucocorticoids on tight junction protein expression in ovine cerebral cortices. Brain Res 2009; 1303:15-25. [PMID: 19785997 DOI: 10.1016/j.brainres.2009.09.086] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2009] [Revised: 09/12/2009] [Accepted: 09/21/2009] [Indexed: 10/20/2022]
Abstract
Maternal glucocorticoid treatment reduces blood-brain permeability early, but not late in fetal development, and pretreatment with glucocorticoids does not affect barrier permeability in newborn lambs. In addition, endogenous increases in plasma cortisol levels are associated with decreases in blood-brain barrier permeability during normal fetal development. Therefore, we tested the hypotheses that development as well as endogenous and exogenous glucocorticoids alters the expression of tight junction proteins in the cerebral cortex of sheep. Cerebral cortices from fetuses at 60%, 70%, and 90% of gestation, newborn and adult sheep were snap frozen after four 6-mg dexamethasone or placebo injections were given over 48-h to the ewes and adult sheep. Lambs were treated similarly with 0.25 mg/kg-dexamethasone or placebo. Tight junction protein expression was measured by Western immunoblot. Claudin-1 was higher (P<0.05) in fetuses at 60% of gestation than in newborn and adult sheep. Claudin-5 was higher at 60% than 70% of gestation, and than in newborn and adult sheep. ZO-1 was higher in newborn than adult sheep. ZO-2 was higher at 90% gestation, in newborn and adult sheep than 60% gestation. Claudin-5 was higher in dexamethasone than placebo-treated lambs, and ZO-2 was higher in fetuses of dexamethasone than placebo-treated ewes at 90% gestation. ZO-2 expression demonstrated a direct correlation with increases in plasma cortisol during fetal development. We conclude that claudin-1, claudin-5, ZO-1, and ZO-2 expression exhibit differential developmental regulation, exogenous glucocorticoids regulate claudin-5 and ZO-2 in vivo at some, but not all ages, and increases in endogenous fetal glucocorticoids are associated with increases in ZO-2 expression, but not with occludin, claudin-1, claudin-5 or ZO-1 expression in ovine cerebral cortices.
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Affiliation(s)
- Anna R Duncan
- The Warren Alpert Medical School of Brown University Department of Pediatrics Women and Infants' Hospital of Rhode Island 101 Dudley Street Providence, RI 02905-2499, USA
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18
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Delivery of Hypoxia Inducible Heme Oxygenase-1 Gene Using Dexamethasone Conjugated Polyethylenimine for Protection of Cardiomyocytes under Hypoxia. B KOREAN CHEM SOC 2009. [DOI: 10.5012/bkcs.2009.30.4.897] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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19
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Sadowska GB, Stopa EG, Stonestreet BS. Ontogeny of connexin 32 and 43 expression in the cerebral cortices of ovine fetuses, newborns, and adults. Brain Res 2009; 1255:51-6. [PMID: 19101525 PMCID: PMC2692885 DOI: 10.1016/j.brainres.2008.12.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Revised: 11/28/2008] [Accepted: 12/02/2008] [Indexed: 11/17/2022]
Abstract
Gap junctions are specialized membrane structures that mediate intercellular communication and facilitate passage of ions and small molecules between adjacent cells. Connexins comprise a multigene family of transmembrane proteins that form gap junctions. Connexin-32 and connexin-43 are among the most abundant connexins in brain and are highly expressed during development. Connexin-32 is expressed primarily in oligodendrocytes and connexin-43 in astrocytes in adult brain. However, both connexins are expressed in neurons during development. We examined the effects of ontogeny on connexin-32 and connexin-43 protein abundance in cerebral cortices of sheep during development. Western immunoblot was used to measure connexin-32 and connexin-43 expression in cerebral cortices of fetuses at 60%, 80%, and 90% of gestation, in newborn lambs and adult sheep. Values were expressed as ratios to a single adult control cerebral cortical sample. Connexin-32 abundance was higher (P<0.05) in cerebral cortices of fetuses at 60% of gestation (3.0+/-0.68, mean+/-SD), than in those at 90% of gestation (1.7+/-0.3), in newborn (1.8+/-0.55), and adult sheep (0.84+/-0.19), respectively. In contrast, connexin-43 abundance was higher (P<0.05) in cerebral cortices of fetuses at 90% of gestation (0.44+/-0.17), newborn (0.69+/-0.12) and adult sheep (1.14+/-0.13), than in those at 60% of gestation (0.05+/-0.01). We conclude that (1) connexin-32 and connexin-43 protein are expressed early in fetal life and throughout development, (2) each connexin displays a unique pattern of change with development, (3) connexin-43 exhibited ontogenic increases in protein abundance, whereas, connexin-32 exhibited reciprocal decreases in abundance late in fetal development, in newborn and adult sheep.
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Affiliation(s)
- Grazyna B. Sadowska
- Department of Pediatrics, Women and Infants’ Hospital of Rhode Island, USA Pathology (Division of Neuropathology), Rhode Island Hospital, USA The Warren Alpert Medical School of Brown University Providence, RI, USA
| | - Edward G. Stopa
- Department of Pediatrics, Women and Infants’ Hospital of Rhode Island, USA Pathology (Division of Neuropathology), Rhode Island Hospital, USA The Warren Alpert Medical School of Brown University Providence, RI, USA
| | - Barbara S. Stonestreet
- Department of Pediatrics, Women and Infants’ Hospital of Rhode Island, USA Pathology (Division of Neuropathology), Rhode Island Hospital, USA The Warren Alpert Medical School of Brown University Providence, RI, USA
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20
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Tight junctions and the regulation of gene expression. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1788:761-7. [PMID: 19121284 DOI: 10.1016/j.bbamem.2008.11.024] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Revised: 11/25/2008] [Accepted: 11/26/2008] [Indexed: 01/08/2023]
Abstract
Cell adhesion is a key regulator of cell differentiation. Cell interactions with neighboring cells and the extracellular matrix regulate gene expression, cell proliferation, polarity and apoptosis. Apical cell-cell junctions participate in these processes using different types of proteins, some of them exhibit nuclear and junctional localization and are called NACos for Nuclear Adhesion Complexes. Tight junctions are one type of such cell-cell junctions and several signaling complexes have been identified to associate with them. In general, expression of tight junction components suppresses proliferation to allow differentiation in a coordinated manner with adherens junctions and extracellular matrix adhesion. These tight junction components have been shown to affect several signaling and transcriptional pathways, and changes in the expression of tight junction proteins are associated with several disease conditions, such as cancer. Here, we will review how tight junction proteins participate in the regulation of gene expression and cell proliferation, as well as how they are regulated themselves by different mechanisms involved in gene expression and cell differentiation.
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21
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Mehter NS, Sadowska GB, Malaeb SN, Stonestreet BS. Na+, K+-ATPase activity and subunit isoform protein abundance: effects of antenatal glucocorticoids in the frontal cerebral cortex and renal cortex of ovine fetuses. Reprod Sci 2008; 16:294-307. [PMID: 19001554 DOI: 10.1177/1933719108325507] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We examined the effects of single and multiple maternal glucocorticoid courses on cerebral cortical (CC) and renal cortical (RC) Na(+),K(+)-ATPase activity and protein isoform abundance in fetal sheep. Ewes received four dexamethasone or placebo injections in the single course (SC) groups, and the same treatment once a week for five-weeks in the multiple course (MC) groups. CC Na(+),K(+)-ATPase a(2)-abundance was higher (P<0.05) and beta(2)-abundance lower in the SC dexamethasone than placebo group, but Na(+),K(+)-ATPase activity did not change. CC Na(+),K(+)-ATPase activity, a(1)-, beta(1) -, and beta(2)-abundance were lower in the MC dexamethasone than placebo group, but a(2)- and a(3)-abundance did not change. Both dexamethasone courses did not affect CC cell number. RC Na(+),K(+)-ATPase activity, a(1)- and beta(1) -abundance were higher in the MC dexamethasone than placebo group, but did not change in the SC dexamethasone group. We conclude MC, but not a SC of dexamethasone, affect fetal cerebral and renal Na(+),K(+)-ATPase, and MC result in differential effects on Na(+),K(+)-ATPase in these organs.
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Affiliation(s)
- Najma S Mehter
- Warren Alpert Medical School of Brown University, Department of Pediatrics, Women & Infants' Hospital of Rhode Island, Providence, Rhode Island 02905, USA
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