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Proisy M, Mitra S, Uria-Avellana C, Sokolska M, Robertson NJ, Le Jeune F, Ferré JC. Brain Perfusion Imaging in Neonates: An Overview. AJNR Am J Neuroradiol 2016; 37:1766-1773. [PMID: 27079367 DOI: 10.3174/ajnr.a4778] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The development of cognitive function in children has been related to a regional metabolic increase and an increase in regional brain perfusion. Moreover, brain perfusion plays an important role in the pathogenesis of brain damage in high-risk neonates, both preterm and full-term asphyxiated infants. In this article, we will review and discuss several existing imaging techniques for assessing neonatal brain perfusion.
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Affiliation(s)
- M Proisy
- From the Department of Radiology (M.P., J.-C.F.), Rennes University Hospital, France .,Department of Neonatology (M.P., S.M., C.U.-A., N.J.R.), University College London Hospital, Institute for Women's Health, University College of London, London, UK.,Inserm VisAGeS Unit U746 (M.P., J.-C.F.), Inria, Rennes 1 University, Rennes, France
| | - S Mitra
- Department of Neonatology (M.P., S.M., C.U.-A., N.J.R.), University College London Hospital, Institute for Women's Health, University College of London, London, UK
| | - C Uria-Avellana
- Department of Neonatology (M.P., S.M., C.U.-A., N.J.R.), University College London Hospital, Institute for Women's Health, University College of London, London, UK
| | - M Sokolska
- Institute of Neurology (M.S.), University College of London, London, UK
| | - N J Robertson
- Department of Neonatology (M.P., S.M., C.U.-A., N.J.R.), University College London Hospital, Institute for Women's Health, University College of London, London, UK
| | - F Le Jeune
- Department of Nuclear Medicine (F.L.J.), Centre Eugène Marquis, Rennes, France
| | - J-C Ferré
- From the Department of Radiology (M.P., J.-C.F.), Rennes University Hospital, France.,Inserm VisAGeS Unit U746 (M.P., J.-C.F.), Inria, Rennes 1 University, Rennes, France
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202
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Nguyen AT, Bahry AMA, Shen KQ, Armstrong EA, Yager JY. Consumption of broccoli sprouts during late gestation and lactation confers protection against developmental delay induced by maternal inflammation. Behav Brain Res 2016; 307:239-49. [PMID: 27038765 DOI: 10.1016/j.bbr.2016.03.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/04/2016] [Accepted: 03/06/2016] [Indexed: 11/27/2022]
Abstract
BACKGROUND The presence of a fetal inflammatory response is linked to cerebral palsy. Unfortunately no preventive therapies are available. In this study, we determined whether dietary supplementation with broccoli sprouts (BrSp), a phase-II enzyme inducer, would be effective in preventing the behavioural and pathologic manifestations in a rodent model of inflammation during late pregnancy. METHODS Pregnant Long-Evans rats were administered i.p. Injections of saline (100μl) or lipopolysaccharide (LPS, 200μg/kg), every 12h on embryonic day (E) 19 and 20. In the treatment groups, dams were supplemented with 200mg/day of dried BrSp from E14 until postnatal day 21. Pups underwent a series of neurodevelopmental reflex tests from postnatal day 3-21 followed by neuropathological analyses. RESULTS Pups born from the LPS group were significantly growth restricted (p<0.001) and delayed in hindlimb placing (p<0.05), cliff avoidance (p<0.05), and gait (p<0.001) compared to controls. In the open field behaviour analyses, LPS pups had an increase in grooming behaviour (p<0.05) and a decreased amount of time spent in the center of the box compared to controls. Dietary supplementation with BrSp to offspring exposed to LPS had increased birth weights (p<0.001), were no longer delayed in acquiring hindlimb placing, cliff avoidance, gait, and posture, and groomed less compared to LPS alone pups (p<0.01). Histological analyses revealed that LPS pups had reduced myelin basic protein compared to controls. CONCLUSIONS Our data suggest that BrSp dietary supplementation during pregnancy may be effective in preventing growth restriction and neurodevelopmental delays.
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Affiliation(s)
| | - Ashley M A Bahry
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Ke Qin Shen
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Edward A Armstrong
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Jerome Y Yager
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.
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203
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Axelrod DM, Chock VY, Reddy VM. Management of the Preterm Infant with Congenital Heart Disease. Clin Perinatol 2016; 43:157-71. [PMID: 26876128 DOI: 10.1016/j.clp.2015.11.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The premature neonate with congenital heart disease (CHD) represents a challenging population for clinicians and researchers. The interaction between prematurity and CHD is poorly understood; epidemiologic study suggests that premature newborns are more likely to have CHD and that fetuses with CHD are more likely to be born premature. Understanding the key physiologic features of this special patient population is paramount. Clinicians have debated optimal timing for referral for cardiac surgery, and management in the postoperative period has rapidly advanced. This article summarizes the key concepts and literature in the care of the premature neonate with CHD.
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Affiliation(s)
- David M Axelrod
- Division of Pediatric Cardiology, Department of Pediatrics, Stanford University Medical Center, 750 Welch Road, Suite 321, Palo Alto, CA 94304, USA.
| | - Valerie Y Chock
- Division of Neonatology, Department of Pediatrics, Stanford University Medical Center, 750 Welch Road, Suite 315, MC 5731, Palo Alto, CA 94304, USA
| | - V Mohan Reddy
- Pediatric Cardiothoracic Surgery, University of California San Francisco Medical Center, 550 16th Street, Floor 5, MH5-745, San Francisco, CA 94143-0117, USA
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204
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Lan KM, Tien LT, Cai Z, Lin S, Pang Y, Tanaka S, Rhodes PG, Bhatt AJ, Savich RD, Fan LW. Erythropoietin Ameliorates Neonatal Hypoxia-Ischemia-Induced Neurobehavioral Deficits, Neuroinflammation, and Hippocampal Injury in the Juvenile Rat. Int J Mol Sci 2016; 17:289. [PMID: 26927081 PMCID: PMC4813153 DOI: 10.3390/ijms17030289] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 01/13/2016] [Accepted: 02/05/2016] [Indexed: 12/11/2022] Open
Abstract
The hematopoietic growth factor erythropoietin (EPO) has been shown to be neuroprotective against hypoxia-ischemia (HI) in Postnatal Day 7 (P7)–P10 or adult animal models. The current study was aimed to determine whether EPO also provides long-lasting neuroprotection against HI in P5 rats, which is relevant to immature human infants. Sprague-Dawley rats at P5 were subjected to right common carotid artery ligation followed by an exposure to 6% oxygen with balanced nitrogen for 1.5 h. Human recombinant EPO (rEPO, at a dose of 5 units/g) was administered intraperitoneally one hour before or immediately after insult, followed by additional injections at 24 and 48 h post-insult. The control rats were injected with normal saline following HI. Neurobehavioral tests were performed on P8 and P20, and brain injury was examined on P21. HI insult significantly impaired neurobehavioral performance including sensorimotor, locomotor activity and cognitive ability on the P8 and P20 rats. HI insult also resulted in brain inflammation (as indicated by microglia activation) and neuronal death (as indicated by Jade B positive staining) in the white matter, striatum, cortex, and hippocampal areas of the P21 rat. Both pre- and post-treatment with rEPO significantly improved neurobehavioral performance and protected against the HI-induced neuronal death, microglia activation (OX42+) as well as loss of mature oligodendrocytes (APC-CC1+) and hippocampal neurons (Nissl+). The long-lasting protective effects of rEPO in the neonatal rat HI model suggest that to exert neurotrophic activity in the brain might be an effective approach for therapeutic treatment of neonatal brain injury induced by hypoxia-ischemia.
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Affiliation(s)
- Kuo-Mao Lan
- Department of Anesthesiology, Chi-Mei General Hospital, Tainan 71004, Taiwan.
- School of Medicine, Fu Jen Catholic University, Xinzhuang District, New Taipei City 24205, Taiwan.
| | - Lu-Tai Tien
- School of Medicine, Fu Jen Catholic University, Xinzhuang District, New Taipei City 24205, Taiwan.
| | - Zhengwei Cai
- Department of Pediatrics, Division of Newborn Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Shuying Lin
- Department of Pediatrics, Division of Newborn Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Yi Pang
- Department of Pediatrics, Division of Newborn Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Sachiko Tanaka
- Department of Pharmacology, Toxicology & Therapeutics, Division of Toxicology, School of Pharmacy, Showa University, Shingawa-ku, Tokyo 142-8555, Japan.
| | - Philip G Rhodes
- Department of Pediatrics, Division of Newborn Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Abhay J Bhatt
- Department of Pediatrics, Division of Newborn Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Renate D Savich
- Department of Pediatrics, Division of Newborn Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Lir-Wan Fan
- Department of Pediatrics, Division of Newborn Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
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205
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Ma Y, Wang J, Wang Y, Yang GY. The biphasic function of microglia in ischemic stroke. Prog Neurobiol 2016; 157:247-272. [PMID: 26851161 DOI: 10.1016/j.pneurobio.2016.01.005] [Citation(s) in RCA: 505] [Impact Index Per Article: 63.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 12/22/2015] [Accepted: 01/10/2016] [Indexed: 12/16/2022]
Abstract
Microglia are brain resident macrophages originated from primitive progenitor cells in the yolk sac. Microglia can be activated within hours and recruited to the lesion site. Traditionally, microglia activation is considered to play a deleterious role in ischemic stroke, as inhibition of microglia activation attenuates ischemia induced brain injury. However, increasing evidence show that microglia activation is critical for attenuating neuronal apoptosis, enhancing neurogenesis, and promoting functional recovery after cerebral ischemia. Differential polarization of microglia could likely explain the biphasic role of microglia in ischemia. We comprehensively reviewed the mechanisms involved in regulating microglia activation and polarization. The latest discoveries of microRNAs in modulating microglia function are discussed. In addition, the interaction between microglia and other cells including neurons, astrocytes, oligodendrocytes, and stem cells were also reviewed. Future therapies targeting microglia may not exclusively aim at suppressing microglia activation, but also at modulating microglia polarization at different stages of ischemic stroke. More work is needed to elucidate the cellular and molecular mechanisms of microglia polarization under ischemic environment. The roles of microRNAs and transplanted stem cells in mediating microglia activation and polarization during brain ischemia also need to be further studied.
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Affiliation(s)
- Yuanyuan Ma
- Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China; Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Jixian Wang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China; Department of Rehabilitation, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Yongting Wang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China.
| | - Guo-Yuan Yang
- Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China; Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China.
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206
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Prenatal Systemic Hypoxia-Ischemia and Oligodendroglia Loss in Cerebellum. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 949:333-345. [PMID: 27714697 DOI: 10.1007/978-3-319-40764-7_16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Hypoxic-ischemic (HI) injury is an important cause of death and disabilities. Despite all improvements in neonatal care, the number of children who suffer some kind of injury during birth has remained stable in the last decade. A great number of studies have shown alterations in neural cells and many animal models have been proposed in the last 5 decades. Robinson et al. (2005) proposed an HI model in which the uterine arteries are temporarily clamped on the 18th gestation day. The findings were quite similar to the ones observed in postmortem studies. The white matter is clearly damaged, and a great amount of astrogliosis takes place both in the gray and white matters. Motor changes were also found but no data regarding the cerebellum, an important structure related to motor performance, was presented. Using this model, we have shown an increased level of iNOS at P0 and microgliosis and astrogliosis at P9, and astrogliosis at P23 (up to 4 weeks from the insult). NO is important in migration, maturation, and synaptic plasticity, but in exacerbated levels it may also contribute to cellular and tissue damage. We have also evaluated oligodendroglia development in the cerebellum. At P9 in HI animals, we found a decrease in the number of PDGFRα+ cells and an apparent delay in myelination, suggesting a failure in oligodendroglial progenitors migration/maturation and/or in the myelination process. These results point to an injury in cerebellar development that might help to explain the motor problems in HI.
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207
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Gopagondanahalli KR, Li J, Fahey MC, Hunt RW, Jenkin G, Miller SL, Malhotra A. Preterm Hypoxic-Ischemic Encephalopathy. Front Pediatr 2016; 4:114. [PMID: 27812521 PMCID: PMC5071348 DOI: 10.3389/fped.2016.00114] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/05/2016] [Indexed: 11/18/2022] Open
Abstract
Hypoxic-ischemic encephalopathy (HIE) is a recognizable and defined clinical syndrome in term infants that results from a severe or prolonged hypoxic-ischemic episode before or during birth. However, in the preterm infant, defining hypoxic-ischemic injury (HII), its clinical course, monitoring, and outcomes remains complex. Few studies examine preterm HIE, and these are heterogeneous, with variable inclusion criteria and outcomes reported. We examine the available evidence that implies that the incidence of hypoxic-ischemic insult in preterm infants is probably higher than recognized and follows a more complex clinical course, with higher rates of adverse neurological outcomes, compared to term infants. This review aims to elucidate the causes and consequences of preterm hypoxia-ischemia, the subsequent clinical encephalopathy syndrome, diagnostic tools, and outcomes. Finally, we suggest a uniform definition for preterm HIE that may help in identifying infants most at risk of adverse outcomes and amenable to neuroprotective therapies.
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Affiliation(s)
| | - Jingang Li
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia
| | - Michael C Fahey
- Monash Children's Hospital, Melbourne, VIC, Australia; The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia; Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Rod W Hunt
- The Royal Children's Hospital, Melbourne, VIC, Australia; Murdoch Childrens Research Institute, Melbourne, VIC, Australia
| | - Graham Jenkin
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia; Department of Obstetrics and Gynaecology, Monash University, 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
| | - Atul Malhotra
- Monash Children's Hospital, Melbourne, VIC, Australia; The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia; Department of Paediatrics, Monash University, Melbourne, VIC, Australia
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208
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Misumi S, Ueda Y, Nishigaki R, Suzuki M, Ishida A, Jung CG, Hida H. Dysfunction in Motor Coordination in Neonatal White Matter Injury Model Without Apparent Neuron Loss. Cell Transplant 2015; 25:1381-93. [PMID: 26564423 DOI: 10.3727/096368915x689893] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We made a white matter injury (WMI) model with mild hindlimb dysfunction by right common carotid artery occlusion followed by 6% oxygen for 60 min at postnatal day 3 (P3), in which actively proliferating oligodendrocyte (OL) progenitors are mainly damaged. To know whether this model is appropriate for cell therapy using OL progenitors, the pathological response to mild hypoxia-ischemia (H-I) in neurons and OL lineage cells and myelination failure were investigated along with gene expression analysis. In WMI model rats, coordinated motor function, as assessed by the accelerating rotarod test, was impaired. The dysfunction was accompanied by myelination failure in layers I-IV of the sensorimotor cortex. Although several oligo2-positive OLs stained positive for active caspase 3 in the cortex and white matter at 24 h after H-I, few NeuN-positive neurons were apoptotic. Argyrophil-III staining for damaged neurons revealed no increase in the number of degenerating cells in the model. Moreover, the total number of NeuN-positive neurons in the cortex was comparable to that of controls 7 days later. Retrograde labeling of the corticospinal tract with Fluoro-Gold revealed no significant loss of layer V neurons. In addition, no decrease in the numbers of cortical projecting neurons and layers V-VI neurons in both motor and sensory areas was observed. Interestingly, the numbers of inhibitory GABAergic cells immunoreactive for parvalbumin, calretinin, or somatostatin were preserved in the P26 cortex. Gene expression analysis at P5 revealed 98 upregulated and 65 downregulated genes that may relate to cell survival, myelin loss, and differentiation of OLs. These data suggest that impaired motor coordination was not induced by neuron loss but, rather, myelination failure in layers I-IV. As OL lineage cells are mainly damaged, this WMI model might be useful for cell-based therapy by replacing OL progenitors.
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Affiliation(s)
- Sachiyo Misumi
- Department of Neurophysiology and Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
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209
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Gao J, Sun QL, Zhang YM, Li YY, Li H, Hou X, Yu BL, Zhou XH, Yang J. Semi-quantitative assessment of brain maturation by conventional magnetic resonance imaging in neonates with clinically mild hypoxic-ischemic encephalopathy. Chin Med J (Engl) 2015; 128:574-80. [PMID: 25698186 PMCID: PMC4834765 DOI: 10.4103/0366-6999.151646] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background: Mild hypoxic-ischemic encephalopathy (HIE) injury is becoming the major type in neonatal brain diseases. The aim of this study was to assess brain maturation in mild HIE neonatal brains using total maturation score (TMS) based on conventional magnetic resonance imaging (MRI). Methods: Totally, 45 neonates with clinically mild HIE and 45 matched control neonates were enrolled. Gestated age, birth weight, age after birth and postmenstrual age at magnetic resonance (MR) scan were homogenous in the two groups. According to MR findings, mild HIE neonates were divided into three subgroups: Pattern I, neonates with normal MR appearance; Pattern II, preterm neonates with abnormal MR appearance; Pattern III, full-term neonates with abnormal MR appearance. TMS and its parameters, progressive myelination (M), cortical infolding (C), involution of germinal matrix tissue (G), and glial cell migration bands (B), were employed to assess brain maturation and compare difference between HIE and control groups. Results: The mean of TMS was significantly lower in mild HIE group than it in the control group (mean ± standard deviation [SD] 11.62 ± 1.53 vs. 12.36 ± 1.26, P < 0.001). In four parameters of TMS scores, the M and C scores were significantly lower in mild HIE group. Of the three patterns of mild HIE, Pattern I (10 cases) showed no significant difference of TMS compared with control neonates, while Pattern II (22 cases), III (13 cases) all had significantly decreased TMS than control neonates (mean ± SD 10.56 ± 0.93 vs. 11.48 ± 0.55, P < 0.05; 12.59 ± 1.28 vs. 13.25 ± 1.29, P < 0.05). It was M, C, and GM scores that significantly decreased in Pattern II, while for Pattern III, only C score significantly decreased. Conclusions: The TMS system, based on conventional MRI, is an effective method to detect delayed brain maturation in clinically mild HIE. The conventional MRI can reveal the different retardations in subtle structures and development processes among the different patterns of mild HIE.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Jian Yang
- Department of Diagnostic Radiology, The First Hospital of Xi'an Jiaotong University, Xi'an, Shannxi 710061, China
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210
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Agematsu K, Korotcova L, Morton PD, Gallo V, Jonas RA, Ishibashi N. Hypoxia diminishes the protective function of white-matter astrocytes in the developing brain. J Thorac Cardiovasc Surg 2015; 151:265-72.e1-3. [PMID: 26412317 DOI: 10.1016/j.jtcvs.2015.08.076] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 08/17/2015] [Accepted: 08/23/2015] [Indexed: 11/16/2022]
Abstract
OBJECTIVES White-matter injury after surgery is common in neonates with cerebral immaturity secondary to in utero hypoxia. Astrocytes play a central role in brain protection; however, the reaction of astrocytes to hypothermic circulatory arrest (HCA) remains unknown. We investigated the role of astrocytes in white-matter injury after HCA and determined the effects of preoperative hypoxia on this role, using a novel mouse model. METHODS Mice were exposed to hypoxia from days 3 to 11, which is equivalent to the third trimester in humans (prehypoxia, n = 49). Brain slices were transferred to a chamber perfused by cerebrospinal fluid. Oxygen-glucose deprivation (OGD) was performed to simulate ischemia-reperfusion/reoxygenation resulting from circulatory arrest under hypothermia. Astrocyte reactions were compared with preoperative normoxia (prenormoxia; n = 45). RESULTS We observed astrocyte activation after 25°C ischemia-reperfusion/reoxygenation in prenormoxia (P < .01). Astrocyte number after OGD correlated with caspase-3(+) cells (rho = .77, P = .001), confirming that astrogliosis is an important response after HCA. At 3 hours after OGD, astrocytes in prenormoxia had already proliferated and become activated (P < .05). Conversely, astrocytes that developed under hypoxia did not display these responses. At 20 hours after ischemia-reperfusion/reoxygenation, astrogliosis was not observed in prehypoxia, demonstrating that hypoxia altered the response of astrocytes to insult. In contrast to prenormoxia, caspase-3(+) cells in prehypoxia increased after ischemia reperfusion/reoxygenation, compared with control (P < .01). Caspase-3(+) cells were more common with prehypoxia than with prenormoxia (P < .001), suggesting that lack of astrogliosis permits increased white-matter injury. CONCLUSIONS Preoperative hypoxia alters the neuroprotective function of astrocytes. Restoring this function before surgery may be a therapeutic option to reduce postoperative white-matter injury in the immature brain.
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Affiliation(s)
- Kota Agematsu
- Children's National Heart Institute, Children's National Medical Center, Washington, DC; Center for Neuroscience Research, Children's National Medical Center, Washington, DC
| | - Ludmila Korotcova
- Children's National Heart Institute, Children's National Medical Center, Washington, DC; Center for Neuroscience Research, Children's National Medical Center, Washington, DC
| | - Paul D Morton
- Children's National Heart Institute, Children's National Medical Center, Washington, DC; Center for Neuroscience Research, Children's National Medical Center, Washington, DC
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's National Medical Center, Washington, DC
| | - Richard A Jonas
- Children's National Heart Institute, Children's National Medical Center, Washington, DC; Center for Neuroscience Research, Children's National Medical Center, Washington, DC
| | - Nobuyuki Ishibashi
- Children's National Heart Institute, Children's National Medical Center, Washington, DC; Center for Neuroscience Research, Children's National Medical Center, Washington, DC.
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211
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Licht DJ. Brain hypoxia before surgery; a tale of two cells: Astrocytes and oligodendrocytes. J Thorac Cardiovasc Surg 2015; 151:273-4. [PMID: 26463653 DOI: 10.1016/j.jtcvs.2015.09.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 09/03/2015] [Indexed: 11/16/2022]
Affiliation(s)
- Daniel J Licht
- Department of Neurology and Pediatrics, June and Steve Wolfson Laboratory for Clinical and Biomedical Optics, The Children's Hospital of Philadelphia, Philadelphia, Pa.
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212
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Sex differences in cell genesis, hippocampal volume and behavioral outcomes in a rat model of neonatal HI. Exp Neurol 2015; 275 Pt 2:285-95. [PMID: 26376217 DOI: 10.1016/j.expneurol.2015.09.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/27/2015] [Accepted: 09/06/2015] [Indexed: 12/11/2022]
Abstract
Hypoxia-ischemia (HI) of the brain in near-term and term infants is a leading cause of infant mortality and lifelong disability but current therapeutic approaches remain limited. Males consistently display greater vulnerability to the deleterious consequences of HI in both humans and animal models. Neurogenesis increases after neonatal HI and offers a potential therapeutic target for recovery. The steroid hormone estradiol has been extensively explored as a neuroprotectant in adult models of stroke but with mixed results. Less consideration has been afforded to this naturally occurring agent in the developing brain, which has unique challenges from the adult. Using a model of term HI in the rat we have explored the impact of this insult on cell genesis in the hippocampus of males and females and the ability of estradiol treatment immediately after insult to restore function. Both short-term (3 days) and long-term (7 days) post-injury were assessed and revealed that only females had markedly increased cell genesis on the short-term but both sexes were increased long-term. A battery of behavioral tests revealed motor impairment in males and compromised episodic memory while both sexes were modestly impaired in spatial memory. Juvenile social play was also depressed in both sexes after HI. Estradiol therapy improved behavioral performance in both sexes but did not reverse a deficit in hippocampal volume ipsilateral to the insult. Thus the effects of estradiol do not appear to be via cell death or proliferation but rather involve other components of neural functioning.
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213
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Scoring system for periventricular leukomalacia in infants with congenital heart disease. Pediatr Res 2015; 78:304-9. [PMID: 25996891 PMCID: PMC4775272 DOI: 10.1038/pr.2015.99] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/23/2015] [Indexed: 11/08/2022]
Abstract
BACKGROUND Currently two magnetic resonance imaging (MRI) methods have been used to assess periventricular leukomalacia (PVL) severity in infants with congenital heart disease: manual volumetric lesion segmentation and an observational categorical scale. Volumetric classification is labor intensive and the categorical scale is quick but unreliable. We propose the quartered point system (QPS) as a novel, intuitive, time-efficient metric with high interrater agreement. METHODS QPS is an observational scale that asks the rater to score MRIs on the basis of lesion size, number, and distribution. Pre- and postoperative brain MRIs were obtained on term congenital heart disease infants. Three independent observers scored PVL severity using all three methods: volumetric segmentation, categorical scale, and QPS. RESULTS One-hundred and thirty-five MRIs were obtained from 72 infants; PVL was seen in 48 MRIs. Volumetric measurements among the three raters were highly concordant (ρc = 0.94-0.96). Categorical scale severity scores were in poor agreement between observers (κ = 0.17) and fair agreement with volumetrically determined severity (κ = 0.26). QPS scores were in very good agreement between observers (κ = 0.82) and with volumetric severity (κ = 0.81). CONCLUSION QPS minimizes training and sophisticated radiologic analysis and increases interrater reliability. QPS offers greater sensitivity to stratify PVL severity and has the potential to more accurately correlate with neurodevelopmental outcomes.
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Back SA. Brain Injury in the Preterm Infant: New Horizons for Pathogenesis and Prevention. Pediatr Neurol 2015; 53:185-92. [PMID: 26302698 PMCID: PMC4550810 DOI: 10.1016/j.pediatrneurol.2015.04.006] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 03/24/2015] [Accepted: 04/12/2015] [Indexed: 10/23/2022]
Abstract
Preterm neonates are surviving with a milder spectrum of motor and cognitive disabilities that appear to be related to widespread disturbances in cell maturation that target cerebral gray and white matter. Whereas the preterm brain was previously at high risk for destructive lesions, preterm survivors now commonly display less severe injury that is associated with aberrant regeneration and repair responses that result in reduced cerebral growth. Impaired cerebral white matter growth is related to myelination disturbances that are initiated by acute death of premyelinating oligodendrocytes, but are followed by rapid regeneration of premyelinating oligodendrocytes that fail to normally mature to myelinating cells. Although immature neurons are more resistant to cell death than mature neurons, they display widespread disturbances in maturation of their dendritic arbors and synapses, which further contributes to impaired cerebral growth. Thus, even more mild cerebral injury involves disrupted repair mechanisms in which neurons and premyelinating oligodendrocytes fail to fully mature during a critical window in development of neural circuitry. These recently recognized distinct forms of cerebral gray and white matter dysmaturation raise new diagnostic challenges and suggest new therapeutic strategies to promote brain growth and repair.
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Affiliation(s)
- Stephen A. Back
- Departments of Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon, U.S.A
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215
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Jiang P, Zhu T, Xia Z, Gao F, Gu W, Chen X, Yuan T, Yu H. Inhibition of MAPK/ERK signaling blocks hippocampal neurogenesis and impairs cognitive performance in prenatally infected neonatal rats. Eur Arch Psychiatry Clin Neurosci 2015; 265:497-509. [PMID: 25721317 DOI: 10.1007/s00406-015-0588-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 02/19/2015] [Indexed: 12/20/2022]
Abstract
Hippocampus endogenous neurogenesis has been postulated to play a favorable role in brain restoration after injury. However, the underlying molecular mechanisms have been insufficiently deciphered. Here we investigated the potential regulatory capacity of MAPK/ERK signaling on neurogenesis and the associated cognitive performance in prenatally infected neonatal rats. From our data, intrauterine infection could induce hippocampal neuronal apoptosis and promote endogenous repair by evoking neural stem cell proliferation and survival. We also found intrauterine infection could induce increased levels of p-ERK, p-CREB and BDNF, which might be responsible for the potential endogenous rescue system. Furthermore, inhibition of MAPK/ERK signaling could aggravate hippocampal neuronal apoptosis, decrease neurogenesis, and impair the offspring's cognitive performances and could also down-regulate the levels of p-ERK, p-CREB and BDNF. Our data strongly suggest that the activation of MAPK/ERK signaling may play a significant role in promoting survival of newly generated neural stem cells via an anti-apoptotic mechanism, which may be particularly important in endogenous neuroprotection associated with cognitive performance development in prenatally infected rats.
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Affiliation(s)
- Peifang Jiang
- Department of Neurology, Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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216
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Hypoxia-Induced Iron Accumulation in Oligodendrocytes Mediates Apoptosis by Eliciting Endoplasmic Reticulum Stress. Mol Neurobiol 2015; 53:4713-27. [PMID: 26319559 DOI: 10.1007/s12035-015-9389-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 08/11/2015] [Indexed: 10/23/2022]
Abstract
This study was aimed at evaluating the role of increased iron accumulation in oligodendrocytes and its role in their apoptosis in the periventricular white matter damage (PWMD) following a hypoxic injury to the neonatal brain. In response to hypoxia, in the PWM, there was increased expression of proteins involved in iron acquisition, such as iron regulatory proteins (IRP1, IRP2) and transferrin receptor in oligodendrocytes. Consistent with this, following a hypoxic exposure, there was increased accumulation of iron in primary cultured oligodendrocytes. The increased concentration of iron within hypoxic oligodendrocytes was found to elicit ryanodine receptor (RyR) expression, and the expression of endoplasmic reticulum (ER) stress markers such as binding-immunoglobulin protein (BiP) and inositol-requiring enzyme (IRE)-1α. Associated with ER stress, there was reduced adenosine triphosphate (ATP) levels within hypoxic oligodendrocytes. However, treatment with deferoxamine reduced the increased expression of RyR, BiP, and IRE-1α and increased ATP levels in hypoxic oligodendrocytes. Parallel to ER stress there was enhanced reactive oxygen species production within mitochondria of hypoxic oligodendrocytes, which was attenuated when these cells were treated with deferoxamine. At the ultrastructural level, hypoxic oligodendrocytes frequently showed dilated ER and disrupted mitochondria, which became less evident in those treated with deferoxamine. Associated with these subcellular changes, the apoptosis of hypoxic oligodendrocytes was evident with an increase in p53 and caspase-3 expression, which was attenuated when these cells were treated with deferoxamine. Thus, the present study emphasizes that the excess iron accumulated within oligodendrocytes in hypoxic PWM could result in their death by eliciting ER stress and mitochondrial disruption.
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217
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Mallard C, Vexler ZS. Modeling Ischemia in the Immature Brain: How Translational Are Animal Models? Stroke 2015; 46:3006-11. [PMID: 26272384 DOI: 10.1161/strokeaha.115.007776] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 06/19/2015] [Indexed: 12/18/2022]
Affiliation(s)
- Carina Mallard
- From the Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden (C.M.); and Department of Neurology, University California San Francisco (Z.S.V.)
| | - Zinaida S Vexler
- From the Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden (C.M.); and Department of Neurology, University California San Francisco (Z.S.V.).
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218
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Ahmad AS, Satriotomo I, Fazal J, Nadeau SE, Doré S. Considerations for the Optimization of Induced White Matter Injury Preclinical Models. Front Neurol 2015; 6:172. [PMID: 26322013 PMCID: PMC4532913 DOI: 10.3389/fneur.2015.00172] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/20/2015] [Indexed: 11/13/2022] Open
Abstract
White matter (WM) injury in relation to acute neurologic conditions, especially stroke, has remained obscure until recently. Current advances in imaging technologies in the field of stroke have confirmed that WM injury plays an important role in the prognosis of stroke and suggest that WM protection is essential for functional recovery and post-stroke rehabilitation. However, due to the lack of a reproducible animal model of WM injury, the pathophysiology and mechanisms of this injury are not well studied. Moreover, producing selective WM injury in animals, especially in rodents, has proven to be challenging. Problems associated with inducing selective WM ischemic injury in the rodent derive from differences in the architecture of the brain, most particularly, the ratio of WM to gray matter in rodents compared to humans, the agents used to induce the injury, and the location of the injury. Aging, gender differences, and comorbidities further add to this complexity. This review provides a brief account of the techniques commonly used to induce general WM injury in animal models (stroke and non-stroke related) and highlights relevance, optimization issues, and translational potentials associated with this particular form of injury.
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Affiliation(s)
- Abdullah Shafique Ahmad
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease, University of Florida , Gainesville, FL , USA
| | - Irawan Satriotomo
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease, University of Florida , Gainesville, FL , USA
| | - Jawad Fazal
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease, University of Florida , Gainesville, FL , USA
| | - Stephen E Nadeau
- Research Service, Brain Rehabilitation Research Center, Malcom Randall Veterans Affairs Medical Center , Gainesville, FL , USA ; Department of Neurology, University of Florida , Gainesville, FL , USA
| | - Sylvain Doré
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease, University of Florida , Gainesville, FL , USA ; Research Service, Brain Rehabilitation Research Center, Malcom Randall Veterans Affairs Medical Center , Gainesville, FL , USA ; Department of Neurology, University of Florida , Gainesville, FL , USA ; Department of Neuroscience, University of Florida , Gainesville, FL , USA ; Department of Neurology, University of Florida , Gainesville, FL , USA ; Department of Pharmaceutics, University of Florida , Gainesville, FL , USA ; Department of Psychology, University of Florida , Gainesville, FL , USA ; Department of Psychiatry, University of Florida , Gainesville, FL , USA
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219
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Abstract
Neonatal encephalopathy resulting from HI (hypoxia-ischaemia) continues to be a significant cause of mortality and morbidity in infants and children, affecting 1-2/1000 live term births and up to 60% of pre-term births. In order to understand the pathophysiology of this insult, as well as design therapeutic interventions, it is important to establish a relevant animal model for pre-clinical studies. One of the most frequently used models of HI-induced brain damage in immature animals is the unilateral carotid ligation/hypoxia model, initially developed in our laboratory more than 30 years ago. The original model employed the postnatal day 7 rat, whose brain is representative of that of a late gestation, pre-term [32-36 weeks GA (gestational age)] human infant. We, and others, have employed this model to characterize the pathophysiological, biochemical/energetic and neuropathological events following HI, as well as the determination of the unique characteristics of the immature brain that define its vulnerability to, and outcome from, HI. In defining the cascade of events following HI, it has become possible to identify potential targets for intervention and neuroprotection. Currently, the only available therapeutic intervention for neonatal encephalopathy in the term asphyxiated infant is therapeutic hypothermia, although this must be initiated within 6 h of birth and is at best partially effective in moderately injured infants. Ongoing pre-clinical studies are necessary to determine the basis for the partial protection afforded by hypothermia as well as the design of adjunct therapies to improve the outcome. The present review highlights the importance of using a well-characterized and relevant animal model to continue to pursue translational research in neuroprotection for the infant brain.
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220
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Titomanlio L, Fernández-López D, Manganozzi L, Moretti R, Vexler ZS, Gressens P. Pathophysiology and neuroprotection of global and focal perinatal brain injury: lessons from animal models. Pediatr Neurol 2015; 52:566-584. [PMID: 26002050 PMCID: PMC4720385 DOI: 10.1016/j.pediatrneurol.2015.01.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 01/16/2015] [Accepted: 01/24/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND Arterial ischemic stroke occurs more frequently in term newborns than in the elderly, and brain immaturity affects mechanisms of ischemic injury and recovery. The susceptibility to injury of the brain was assumed to be lower in the perinatal period as compared with childhood. This concept was recently challenged by clinical studies showing marked motor disabilities after stroke in neonates, with the severity of motor and cortical sensory deficits similar in both perinatal and childhood ischemic stroke. Our understanding of the triggers and the pathophysiological mechanisms of perinatal stroke has greatly improved in recent years, but many factors remain incompletely understood. METHODS In this review, we focus on the pathophysiology of perinatal stroke and on therapeutic strategies that can protect the immature brain from the consequences of stroke by targeting inflammation and brain microenvironment. RESULTS Studies in neonatal rodent models of cerebral ischemia have suggested a potential role for soluble inflammatory molecules as important modulators of injury and recovery. A great effort is underway to investigate neuroprotective molecules based on our increasing understanding of the pathophysiology. CONCLUSION In this review, we provide a comprehensive summary of new insights concerning pathophysiology of focal and global perinatal brain injury and their implications for new therapeutic approaches.
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Affiliation(s)
- Luigi Titomanlio
- Pediatric Emergency Department, APHP, Robert Debré Hospital, Paris, France
- Inserm, U1141, F-75019 Paris, France
| | - David Fernández-López
- Department of Neurology, University of California San Francisco, San Francisco, CA, 94158-0663, USA
| | - Lucilla Manganozzi
- Pediatric Emergency Department, APHP, Robert Debré Hospital, Paris, France
- Inserm, U1141, F-75019 Paris, France
| | | | - Zinaida S. Vexler
- Department of Neurology, University of California San Francisco, San Francisco, CA, 94158-0663, USA
| | - Pierre Gressens
- Inserm, U1141, F-75019 Paris, France
- Univ Paris Diderot, Sorbonne Paris Cité, UMRS 676, F-75019 Paris, France
- PremUP, Paris, France
- Centre for the Developing Brain, King’s College, St Thomas’ Campus, London SE1 7EH, UK
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221
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Venkat P, Chopp M, Chen J. Models and mechanisms of vascular dementia. Exp Neurol 2015; 272:97-108. [PMID: 25987538 DOI: 10.1016/j.expneurol.2015.05.006] [Citation(s) in RCA: 200] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 05/04/2015] [Accepted: 05/08/2015] [Indexed: 02/02/2023]
Abstract
Vascular dementia (VaD) is the second leading form of dementia after Alzheimer's disease (AD) plaguing the elderly population. VaD is a progressive disease caused by reduced blood flow to the brain, and it affects cognitive abilities especially executive functioning. VaD is poorly understood and lacks suitable animal models, which constrain the progress on understanding the basis of the disease and developing treatments. This review article discusses VaD, its risk factors, induced cognitive disability, various animal (rodent) models of VaD, pathology, and mechanisms of VaD and treatment options.
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Affiliation(s)
- Poornima Venkat
- Neurology, Henry Ford Hospital, Detroit, MI, USA; Physics, Oakland University, Rochester, MI, USA.
| | - Michael Chopp
- Neurology, Henry Ford Hospital, Detroit, MI, USA; Physics, Oakland University, Rochester, MI, USA.
| | - Jieli Chen
- Neurology, Henry Ford Hospital, Detroit, MI, USA; Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute, Tianjin, China.
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222
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Zhu L, Qian L, Wang S, Wang T, Jiang L. Expression of ephrinB2 and EphB4 in a neonatal rat model of periventricular white matter damage. J Perinat Med 2015; 43:367-71. [PMID: 25222588 DOI: 10.1515/jpm-2014-0096] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 08/08/2014] [Indexed: 12/25/2022]
Abstract
BACKGROUND Periventricular white matter damage (PWMD), also termed periventricular leukomalacia, is the predominant neurologic lesion in preterm infants. It appears to relate in part to the development of the vascular supply to the cerebral white matter. We investigated whether, in case of severe hypoxia-ischemia, the vascular system would be subject to severe damage or remodeled. AIMS To evaluate microvessel density (MVD) and the use of ephrinB2 and its receptor EphB4 to mark arterioles and venules to establish the correct anatomic assignment of the remodeled vessels in a hypoxia-induced PWMD rat model. METHODS Postnatal day 3 rats underwent permanent ligation of the right common carotid artery followed by 6% O2 for 4 h (hypoxia-ischemia) or sham operation and normoxic exposure (sham). MVD and levels of ephrinB2 and EphB4, which are respectively regarded as relatively specific molecular markers of arteries and veins, were determined at postnatal day 7. RESULTS Compared with sham rats, MVD, ephrinB2 and EphB4 levels were higher in the brains of hypoxic-ischemic rats. Similar percentages of vessels expressed ephrinB2 and EphB4 in sham rats, but expression of ephrinB2 was greater in brains injured by hypoxia-ischemia. CONCLUSIONS Following hypoxic-ischemic injury to the rat brain, microvessels were remodeled and more arterioles than venules were acquired.
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223
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Zonouzi M, Scafidi J, Li P, McEllin B, Edwards J, Dupree JL, Harvey L, Sun D, Hübner CA, Cull-Candy SG, Farrant M, Gallo V. GABAergic regulation of cerebellar NG2 cell development is altered in perinatal white matter injury. Nat Neurosci 2015; 18:674-82. [PMID: 25821912 PMCID: PMC4459267 DOI: 10.1038/nn.3990] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/06/2015] [Indexed: 01/11/2023]
Abstract
Diffuse white matter injury (DWMI), a leading cause of neurodevelopmental disabilities in preterm infants, is characterized by reduced oligodendrocyte formation. NG2-expressing oligodendrocyte precursor cells (NG2 cells) are exposed to various extrinsic regulatory signals, including the neurotransmitter GABA. We investigated GABAergic signaling to cerebellar white matter NG2 cells in a mouse model of DWMI (chronic neonatal hypoxia). We found that hypoxia caused a loss of GABAA receptor-mediated synaptic input to NG2 cells, extensive proliferation of these cells and delayed oligodendrocyte maturation, leading to dysmyelination. Treatment of control mice with a GABAA receptor antagonist or deletion of the chloride-accumulating transporter NKCC1 mimicked the effects of hypoxia. Conversely, blockade of GABA catabolism or GABA uptake reduced NG2 cell numbers and increased the formation of mature oligodendrocytes both in control and hypoxic mice. Our results indicate that GABAergic signaling regulates NG2 cell differentiation and proliferation in vivo, and suggest that its perturbation is a key factor in DWMI.
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MESH Headings
- Action Potentials/drug effects
- Animals
- Animals, Newborn
- Asphyxia Neonatorum/pathology
- Carbachol/pharmacology
- Cell Count
- Cells, Cultured
- Cerebellum/growth & development
- Cerebellum/pathology
- Demyelinating Diseases/chemically induced
- Demyelinating Diseases/etiology
- Disease Models, Animal
- Female
- GABA-A Receptor Antagonists/toxicity
- Hypoxia, Brain/pathology
- Hypoxia, Brain/physiopathology
- Interneurons/pathology
- Male
- Mice
- Mice, Knockout
- Mice, Transgenic
- Neural Stem Cells/cytology
- Neurogenesis/drug effects
- Neurogenesis/physiology
- Nipecotic Acids/pharmacology
- Nipecotic Acids/therapeutic use
- Oligodendroglia/cytology
- Purkinje Cells/pathology
- Receptors, GABA-A/physiology
- Solute Carrier Family 12, Member 2/deficiency
- Solute Carrier Family 12, Member 2/physiology
- Tiagabine
- Vigabatrin/pharmacology
- Vigabatrin/therapeutic use
- White Matter/injuries
- gamma-Aminobutyric Acid/physiology
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Affiliation(s)
- Marzieh Zonouzi
- 1] Center for Neuroscience Research, Children's Research Institute, Children's National Medical Center, Washington, DC, USA. [2] Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Joseph Scafidi
- 1] Center for Neuroscience Research, Children's Research Institute, Children's National Medical Center, Washington, DC, USA. [2] Department of Neurology, Children's National Medical Center, Washington, DC, USA
| | - Peijun Li
- Center for Neuroscience Research, Children's Research Institute, Children's National Medical Center, Washington, DC, USA
| | - Brian McEllin
- Center for Neuroscience Research, Children's Research Institute, Children's National Medical Center, Washington, DC, USA
| | - Jorge Edwards
- Center for Neuroscience Research, Children's Research Institute, Children's National Medical Center, Washington, DC, USA
| | - Jeffrey L Dupree
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Medical Center, Richmond, Virginia, USA
| | - Lloyd Harvey
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Christian A Hübner
- Friedrich-Schiller-University Jena, Institute of Human Genetics, Jena University Hospital, Jena, Germany
| | - Stuart G Cull-Candy
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Mark Farrant
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's Research Institute, Children's National Medical Center, Washington, DC, USA
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224
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Basilious A, Yager J, Fehlings MG. Neurological outcomes of animal models of uterine artery ligation and relevance to human intrauterine growth restriction: a systematic review. Dev Med Child Neurol 2015; 57:420-30. [PMID: 25330710 PMCID: PMC4406147 DOI: 10.1111/dmcn.12599] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/18/2014] [Indexed: 01/07/2023]
Abstract
AIM This review explores the molecular, neurological, and behavioural outcomes in animal models of uterine artery ligation. We analyse the relevance of this type of model to the pathological and functional phenotypes that are consistent with cerebral palsy and its developmental comorbidities in humans. METHOD A literature search of the PubMed database was conducted for research using the uterine artery ligation model published between 1990 and 2013. From the studies included, any relevant neuroanatomical and behavioural deficits were then summarized from each document and used for further analysis. RESULTS There were 25 papers that met the criteria included for review, and several outcomes were summarized from the results of these papers. Fetuses with growth restriction demonstrated a gradient of reduced body weight with a relative sparing of brain mass. There was a significant reduction in the size of the somatosensory cortex, hippocampus, and corpus callosum. The motor cortex appeared to be spared of identifiable deficits. Apoptotic proteins were upregulated, while those important to neuronal survival, growth, and differentiation were downregulated. Neuronal apoptosis and astrogliosis occurred diffusely throughout the brain regions. White matter injury involved oligodendrocyte precursor maturation arrest, hypomyelination, and an aberrant organization of existing myelin. Animals with growth restriction demonstrated deficits in gait, memory, object recognition, and spatial processing. INTERPRETATION This review concludes that neuronal death, white matter injury, motor abnormalities, and cognitive deficits are important outcomes of uterine artery ligation in animal models. Therefore, this is a clinically relevant type of model, as these findings resemble deficits in human cerebral palsy.
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Affiliation(s)
| | - Jerome Yager
- Department of Pediatrics, University of AlbertaEdmonton, AB, Canada
| | - Michael G Fehlings
- Faculty of Medicine, University of TorontoToronto, ON, Canada,Toronto Western Research Institute and Krembil Neuroscience Centre, University Health NetworkToronto, ON, Canada,Department of Surgery, University of TorontoToronto, ON, Canada,
Correspondence to Michael Fehlings, Toronto Western Hospital 4WW449, 399 Bathurst St, Toronto, ON, Canada M5T 2S8. E-mail:
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225
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Deng YP, Sun Y, Hu L, Li ZH, Xu QM, Pei YL, Huang ZH, Yang ZG, Chen C. Chondroitin sulfate proteoglycans impede myelination by oligodendrocytes after perinatal white matter injury. Exp Neurol 2015; 269:213-23. [PMID: 25862289 DOI: 10.1016/j.expneurol.2015.03.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 03/09/2015] [Accepted: 03/31/2015] [Indexed: 01/22/2023]
Abstract
Hypomyelination is the major cause of neurodevelopmental deficits that are associated with perinatal white matter injury. Chondroitin sulfate proteoglycans (CSPGs) are known to exert inhibitory effects on the migration and differentiation of oligodendrocytes (OLs). However, few studies describe the roles of CSPGs in myelination by OLs and the cognitive dysfunction that follows perinatal white matter injury. Here, we examined the alterations in the expression of CSPGs and their functional impact on the maturation of OLs and myelination in a neonatal rat model of hypoxic-ischemic (HI) brain injury. Three-day-old Sprague-Dawley rats underwent a right common carotid artery ligation and were exposed to hypoxia (6% oxygen for 2.5h). Rats were given chondroitinase ABC (cABC) via an intracerebroventricular injection to digest CSPGs. Animals were sacrificed at 7, 14, 28 and 56days after HI injury and the accompanying surgical procedure. We found that the expression of CSPGs was significantly up-regulated in the cortical regions surrounding the white matter after HI injury. cABC successfully degraded CSPGs in the rats that received cABC. Immunostaining showed decreased expression of the pre-oligodendrocyte marker O4 in the cingulum, external capsule and corpus callosum in HI+cABC rats compared to HI rats. However HI+cABC rats exhibited greater maturation of OLs than did HI rats, with increased expression of O1 and myelin basic protein in the white matter. Furthermore, using electron microscopy, we demonstrated that myelin formation was enhanced in HI+cABC rats, which had an increased number of myelinated axons and decreased G-ratios of myelin compared to HI rats. Finally, HI+cABC rats performed better in the Morris water maze task than HI rats, which indicates an improvement in cognitive ability. Our results suggest that CSPGs inhibit both the maturation of OLs and the process of myelination after neonatal HI brain injury. The data also raise the possibility that modifying CSPGs may repair this type of lesion associated with demyelination.
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Affiliation(s)
- Ying-Ping Deng
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China; Key Laboratory of Neonatal Disease, Ministry of Health, Shanghai, China
| | - Yi Sun
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
| | - Lan Hu
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
| | - Zhi-Hua Li
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
| | - Quan-Mei Xu
- Key Laboratory of Neonatal Disease, Ministry of Health, Shanghai, China
| | - Yi-Ling Pei
- School of Public Health, Fudan University, Shanghai, China
| | - Zhi-Heng Huang
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China; Key Laboratory of Neonatal Disease, Ministry of Health, Shanghai, China
| | - Zhen-Gang Yang
- Institute of Brain Science, Fudan University, Shanghai, China
| | - Chao Chen
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China; Key Laboratory of Neonatal Disease, Ministry of Health, Shanghai, China.
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226
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Morin EC, Schleger F, Preissl H, Braendle J, Eswaran H, Abele H, Brucker S, Kiefer-Schmidt I. Functional brain development in growth-restricted and constitutionally small fetuses: a fetal magnetoencephalography case-control study. BJOG 2015; 122:1184-90. [DOI: 10.1111/1471-0528.13347] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/26/2015] [Indexed: 11/26/2022]
Affiliation(s)
- EC Morin
- Department of Obstetrics and Gynaecology; University of Tuebingen; Tuebingen Germany
- fMEG-Center; University of Tuebingen; Tuebingen Germany
| | - F Schleger
- fMEG-Center; University of Tuebingen; Tuebingen Germany
| | - H Preissl
- fMEG-Center; University of Tuebingen; Tuebingen Germany
| | - J Braendle
- Department of Obstetrics and Gynaecology; University of Tuebingen; Tuebingen Germany
- fMEG-Center; University of Tuebingen; Tuebingen Germany
| | - H Eswaran
- SARA Research Center; Department of Obstetrics and Gynecology; University of Arkansas for Medical Sciences; Little Rock AR USA
| | - H Abele
- Department of Obstetrics and Gynaecology; University of Tuebingen; Tuebingen Germany
| | - S Brucker
- Department of Obstetrics and Gynaecology; University of Tuebingen; Tuebingen Germany
- University Women's Hospital and Research Institute for Women's Health; Tuebingen Germany
| | - I Kiefer-Schmidt
- Department of Obstetrics and Gynaecology; University of Tuebingen; Tuebingen Germany
- fMEG-Center; University of Tuebingen; Tuebingen Germany
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227
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Protective effects of N-acetyl-L-cysteine in human oligodendrocyte progenitor cells and restoration of motor function in neonatal rats with hypoxic-ischemic encephalopathy. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:764251. [PMID: 25918547 PMCID: PMC4396975 DOI: 10.1155/2015/764251] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 03/15/2015] [Accepted: 03/16/2015] [Indexed: 12/29/2022]
Abstract
Objective. Since oligodendrocyte progenitor cells (OPCs) are the target cells of neonatal hypoxic-ischemic encephalopathy (HIE), the present study was aimed at investigating the protective effects of N-acetyl-l-cysteine (NAC), a well-known antioxidant and precursor of glutathione, in OPCs as well as in neonatal rats. Methods. In in vitro study, protective effects of NAC on KCN cytotoxicity in F3.Olig2 OPCs were investigated via MTT assay and apoptotic signal analysis. In in vivo study, NAC was administered to rats with HIE induced by hypoxia-ischemia surgery at postnatal day 7, and their motor functions and white matter demyelination were analyzed. Results. NAC decreased KCN cytotoxicity in F3.Olig2 cells and especially suppressed apoptosis by regulating Bcl2 and p-ERK. Administration of NAC recovered motor functions such as the using ratio of forelimb contralateral to the injured brain, locomotor activity, and rotarod performance of neonatal HIE animals. It was also confirmed that NAC attenuated demyelination in the corpus callosum, a white matter region vulnerable to HIE. Conclusion. The results indicate that NAC exerts neuroprotective effects in vitro and in vivo by preserving OPCs, via regulation of antiapoptotic signaling, and that F3.Olig2 human OPCs could be a good tool for screening of candidates for demyelinating diseases.
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Roux C, Aligny C, Lesueur C, Girault V, Brunel V, Ramdani Y, Genty D, Driouich A, Laquerrière A, Marret S, Brasse-Lagnel C, Gonzalez BJ, Bekri S. NMDA receptor blockade in the developing cortex induces autophagy-mediated death of immature cortical GABAergic interneurons: An ex vivo and in vivo study in Gad67-GFP mice. Exp Neurol 2015; 267:177-93. [PMID: 25795167 DOI: 10.1016/j.expneurol.2015.02.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 01/14/2015] [Accepted: 02/05/2015] [Indexed: 01/16/2023]
Abstract
In neonates, excitotoxicity is a major process involved in hypoxic-ischemic brain lesions, and several research groups have suggested the use of NMDA antagonists for neuroprotection. However, despite their clinical interest, there is more and more evidence suggesting that, in the immature brain, these molecules exert deleterious actions on migrating GABAergic interneurons by suppressing glutamatergic trophic inputs. Consequently, preventing the side effects of NMDA antagonists would be therapeutically useful. Because macroautophagy is involved in the adaptive response to trophic deprivation, the aim of the present study was to investigate the impact of autophagy modulators on the MK801-induced death of immature GABAergic interneurons and to characterize the crosstalk between autophagic and apoptotic mechanisms in this cell type. Ex vivo, using cortical slices from NMRI and Gad67-GFP mice, we show that blockade of the NMDA receptor results in an accumulation of autophagosomes due to the disruption of the autophagic flux. This effect precedes the activation of the mitochondrial apoptotic pathway, and the degeneration of immature GABAergic neurons present in developing cortical layers II-IV and is prevented by 3-MA, an autophagy inhibitor. In contrast, modulators of autophagy (3-MA, rapamycin) do not interfere with the anti-excitotoxic and neuroprotective effect of MK801 observed in deep layers V and VI. In vivo, 3-MA blocks the rapid increase in caspase-3 cleavage induced by the blockade of NMDA receptors and prevents the resulting long-term decrease in Gad67-GFP neurons in layers II-IV. Together, these data suggest that, in the developing cortex, the suppression of glutamatergic inputs through NMDA receptor inhibition results in the impairment of the autophagic flux and the subsequent switch to apoptotic death of immature GABAergic interneurons. The concomitant inhibition of autophagy prevents this pro-apoptotic action of the NMDA blocker and favors the long-term rescue of GABAergic interneurons without interfering with its neuroprotective actions. The use of autophagy modulators in the developing brain would create new opportunities to prevent the side effects of NMDA antagonists used for neuroprotection or anesthesia.
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Affiliation(s)
- Christian Roux
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France
| | - Caroline Aligny
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France
| | - Céline Lesueur
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France
| | - Virginie Girault
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France
| | - Valery Brunel
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France
| | - Yasmina Ramdani
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France
| | - Damien Genty
- Department of Pathology, Rouen University Hospital, Rouen, France
| | - Azeddine Driouich
- Research Platform of Cell Imagery (PRIMACEN), France; Laboratory of Glycobiology and Plant Extracellular Matrix (GLYCOMEV) EA 4358, France
| | - Annie Laquerrière
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Pathology, Rouen University Hospital, Rouen, France
| | - Stéphane Marret
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Neonatal Paediatrics and Intensive Care, Rouen University Hospital, Rouen, France
| | - Carole Brasse-Lagnel
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France
| | - Bruno J Gonzalez
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France.
| | - Soumeya Bekri
- Region-Inserm Team NeoVasc ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, Normandy University, Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France
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Decima PFF, Fyfe KL, Odoi A, Wong FY, Horne RSC. The longitudinal effects of persistent periodic breathing on cerebral oxygenation in preterm infants. Sleep Med 2015; 16:729-35. [PMID: 25959095 DOI: 10.1016/j.sleep.2015.02.537] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 01/14/2015] [Accepted: 02/13/2015] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Periodic breathing is common in preterm infants, but is thought to be benign. The aim of our study was to assess the incidence and impact of periodic breathing on heart rate (HR), oxygen saturation (SpO2), and brain tissue oxygenation index (TOI) over the first six months after term-equivalent age. STUDY DESIGN Twenty-four preterm infants (27-36 weeks gestational age) were studied with daytime polysomnography in quiet sleep (QS) and active sleep (AS) and in both the prone and supine positions at 2-4 weeks, 2-3 months, and 5-6 months post-term corrected age. HR, SpO2, and TOI (NIRO-200 spectrophotometer) were recorded. Periodic breathing episodes were defined as greater than or equal to three sequential apneas each lasting ≥3 s. RESULTS A total 164 individual episodes of periodic breathing were recorded in 19 infants at 2-4 weeks, 62 in 12 infants at 2-3 months, and 35 in 10 infants at 5-6 months. There was no effect of gestational age on periodic breathing frequency or duration. Falls in HR (-21.9 ± 2.7%) and TOI (-13.1 ± 1.5%) were significantly greater at 2-3 months of age compared to 2-4 weeks of age. CONCLUSIONS The majority of preterm infants discharged home without clinical respiratory problems had persistent periodic breathing. Although in most infants periodic breathing was not associated with significant falls in SpO2 or TOI, several infants had significant desaturations and reduced cerebral oxygenation especially during AS. The clinical significance of this on neurodevelopmental outcome is unknown and warrants further investigations.
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MESH Headings
- Brain/physiopathology
- Cross-Sectional Studies
- Female
- Follow-Up Studies
- Gestational Age
- Heart Rate/physiology
- Humans
- Hypoxia, Brain/diagnosis
- Hypoxia, Brain/epidemiology
- Hypoxia, Brain/physiopathology
- Infant
- Infant, Newborn
- Infant, Premature, Diseases/diagnosis
- Infant, Premature, Diseases/epidemiology
- Infant, Premature, Diseases/physiopathology
- Longitudinal Studies
- Male
- Oxygen/blood
- Oxygen Consumption/physiology
- Polysomnography
- Sleep Apnea, Central/diagnosis
- Sleep Apnea, Central/epidemiology
- Sleep Apnea, Central/physiopathology
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Affiliation(s)
- Pauline F F Decima
- The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute, Monash University, Melbourne, VIC, Australia; Laboratoire PériTox, UMR-I 01 INERIS, Faculté de Médecine, Université de Picardie Jules Verne, Amiens, France
| | - Karinna L Fyfe
- The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute, Monash University, Melbourne, VIC, Australia; Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Alexsandria Odoi
- The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute, Monash University, Melbourne, VIC, Australia
| | - Flora Y Wong
- The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute, Monash University, Melbourne, VIC, Australia; Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Rosemary S C Horne
- The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute, Monash University, Melbourne, VIC, Australia; Department of Paediatrics, Monash University, Melbourne, VIC, Australia.
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Sexual dimorphism and brain lateralization impact behavioral and histological outcomes following hypoxia-ischemia in P3 and P7 rats. Neuroscience 2015; 290:581-93. [PMID: 25620049 DOI: 10.1016/j.neuroscience.2014.12.074] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 12/11/2014] [Accepted: 12/21/2014] [Indexed: 01/12/2023]
Abstract
Neonatal cerebral hypoxia-ischemia (HI) is a major cause of neurological disorders and the most common cause of death and permanent disability worldwide, affecting 1-2/1000 live term births and up to 60% of preterm births. The Levine-Rice is the main experimental HI model; however, critical variables such as the age of animals, sex and hemisphere damaged still receive little attention in experimental design. We here investigated the influence of sex and hemisphere injured on the functional outcomes and tissue damage following early (hypoxia-ischemia performed at postnatal day 3 (HIP3)) and late (hypoxia-ischemia performed at postnatalday 7 (HIP7)) HI injury in rats. Male and female 3- (P3) or 7-day-old (P7) Wistar rats had their right or left common carotid artery occluded and exposed to 8% O2 for 1.5h. Sham animals had their carotids exposed but not occluded nor submitted to the hypoxic atmosphere. Behavioral impairments were assessed in the open field arena, in the Morris water maze and in the inhibitory avoidance task; volumetric extent of tissue damage was assessed using cresyl violet staining at adult age, after completing behavioral assessment. The overall results demonstrate that: (1) HI performed at the two distinct ages cause different behavioral impairments and histological damage in adult rats (2) behavioral deficits following neonatal HIP3 and HIP7 are task-specific and dependent on sex and hemisphere injured (3) HIP7 animals presented the expected motor and cognitive deficits (4) HIP3 animals displayed discrete but significant cognitive impairments in the left hemisphere-injured females (5) HI brain injury and its consequences are determined by animal's sex and the damaged hemisphere, markedly in HIP3-injured animals.
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231
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Back SA, Riddle A, Hohimer AR. The Sheep as a Model of Brain Injury in the Premature Infant. ANIMAL MODELS OF NEURODEVELOPMENTAL DISORDERS 2015. [DOI: 10.1007/978-1-4939-2709-8_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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232
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Gizzi C, Montecchia F, Panetta V, Castellano C, Mariani C, Campelli M, Papoff P, Moretti C, Agostino R. Is synchronised NIPPV more effective than NIPPV and NCPAP in treating apnoea of prematurity (AOP)? A randomised cross-over trial. Arch Dis Child Fetal Neonatal Ed 2015; 100:F17-23. [PMID: 25318667 DOI: 10.1136/archdischild-2013-305892] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Apnoea, desaturations and bradycardias are common problems in preterm infants which can be treated with nasal continuous positive airway pressure (NCPAP) and nasal intermittent positive pressure ventilation (NIPPV). It is unclear whether synchronised NIPPV (SNIPPV) would be even more effective. OBJECTIVE To assess the effects of flow-SNIPPV, NIPPV and NCPAP on the rate of desaturations and bradycardias in preterm infants and, secondarily, to evaluate their influence on pattern of breathing and gas exchange. PATIENTS AND METHODS Nineteen infants (mean gestational age at study 30 weeks, 9 boys) with apnoeic spells were enrolled in a randomised controlled trial with a cross-over design. They received flow-SNIPPV, NIPPV and NCPAP for 4 h each. All modes were provided by a nasal conventional ventilator able to provide synchronisation by a pneumotachograph. The primary outcome was the event rate of desaturations (≤80% arterial oxygen saturation) and bradycardias (≤80 bpm) per hour, obtained from cardiorespiratory recordings. The incidence of central apnoeas (≥10 s) as well as baseline heart rate, FiO2, SpO2, transcutaneous blood gases and respiratory rate were also evaluated. RESULTS The median event rate per hour during flow-SNIPPV, NIPPV and NCPAP was 2.9, 6.1 and 5.9, respectively (p<0.001 and 0.009, compared with flow-SNIPPV). Central apnoeas per hour were 2.4, 6.3 and 5.4, respectively (p=0.001, for both compared with flow-SNIPPV), while no differences in any other parameter studied were recorded. CONCLUSIONS Flow-SNIPPV seems more effective than NIPPV and NCPAP in reducing the incidence of desaturations, bradycardias and central apnoea episodes in preterm infants.
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Affiliation(s)
- Camilla Gizzi
- Neonatal Intensive Care Unit, Pediatric and Neonatal Department, "S.Giovanni Calibita" Fatebenefratelli Hospital, Rome, Italy
| | - Francesco Montecchia
- Medical Engineering Laboratory, Department of Civil Engineering and Computer Science Engineering, "Tor Vergata" University of Rome, Rome, Italy
| | - Valentina Panetta
- SeSMIT-A.Fa.R., Medical Statistics & Information Technology, Fatebenefratelli Association for Biomedical and Sanitary Research, Rome, Italy
| | - Chiara Castellano
- Neonatal Intensive Care Unit, Pediatric and Neonatal Department, "S.Giovanni Calibita" Fatebenefratelli Hospital, Rome, Italy
| | - Chiara Mariani
- Neonatal Intensive Care Unit, Pediatric and Neonatal Department, "S.Giovanni Calibita" Fatebenefratelli Hospital, Rome, Italy
| | - Maristella Campelli
- Neonatal Intensive Care Unit, Pediatric and Neonatal Department, "S.Giovanni Calibita" Fatebenefratelli Hospital, Rome, Italy
| | - Paola Papoff
- Pediatric Emergency and Intensive Care, Department of Pediatrics, Policlinico "Umberto I," Sapienza University of Rome, Rome, Italy
| | - Corrado Moretti
- Pediatric Emergency and Intensive Care, Department of Pediatrics, Policlinico "Umberto I," Sapienza University of Rome, Rome, Italy
| | - Rocco Agostino
- Neonatal Intensive Care Unit, Pediatric and Neonatal Department, "S.Giovanni Calibita" Fatebenefratelli Hospital, Rome, Italy
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O'Gorman RL, Bucher HU, Held U, Koller BM, Hüppi PS, Hagmann CF. Tract-based spatial statistics to assess the neuroprotective effect of early erythropoietin on white matter development in preterm infants. ACTA ACUST UNITED AC 2014; 138:388-97. [PMID: 25534356 DOI: 10.1093/brain/awu363] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Despite improved survival, many preterm infants undergo subsequent neurodevelopmental impairment. To date, no neuroprotective therapies have been implemented into clinical practice. Erythropoietin, a haematopoietic cytokine used for treatment of anaemia of prematurity, has been shown to have neuroprotective and neuroregenerative effects on the brain in many experimental studies. The aim of the study was to assess the effect of recombinant human erythropoietin on the microstructural development of the cerebral white matter using tract-based spatial statistics performed at term equivalent age. A randomized, double-blind placebo-controlled, prospective multicentre study applying recombinant human erythropoietin in the first 42 h after preterm birth entitled 'Does erythropoietin improve outcome in preterm infant' was conducted in Switzerland (NCT00413946). Preterm infants were given recombinant human erythropoietin (3000 IU) or an equivalent volume of placebo (NaCl 0.9%) intravenously before 3 h of age after birth, at 12-18 h and at 36-42 h after birth. High resolution diffusion tensor imaging was obtained at 3 T in 58 preterm infants with mean (standard deviation) gestational age at birth 29.75 (1.44) weeks, and at scanning at 41.1 (2.09) weeks. Imaging was performed at a single centre. Voxel-wise statistical analysis of the fractional anisotropy data was carried out using tract-based spatial statistics to test for differences in fractional anisotropy between infants treated with recombinant human erythropoietin and placebo using a general linear model, covarying for the gestational age at birth and the corrected gestational age at the time of the scan. Preterm infants treated with recombinant human erythropoietin demonstrated increased fractional anisotropy in the genu and splenium of the corpus callosum, the anterior and posterior limbs of the internal capsule, and the corticospinal tract bilaterally. Mean fractional anisotropy was significantly higher in preterm infants treated with recombinant human erythropoietin than in those treated with placebo (P < 0.001). We conclude that early recombinant human erythropoietin administration improves white matter development in preterm infants assessed by diffusion tensor imaging and tract-based spatial statistics.
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Affiliation(s)
- Ruth L O'Gorman
- 1 MR Research Centre, Children's University Hospital of Zurich, Switzerland
| | - Hans U Bucher
- 2 Department of Neonatology, University Hospital of Zurich, Switzerland
| | - Ulrike Held
- 3 Horten Centre, University Hospital of Zurich, Switzerland
| | - Brigitte M Koller
- 2 Department of Neonatology, University Hospital of Zurich, Switzerland
| | - Petra S Hüppi
- 3 Horten Centre, University Hospital of Zurich, Switzerland 4 Division of Development and Growth, Department of Paediatrics, University of Geneva, Switzerland
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Clowry GJ, Basuodan R, Chan F. What are the Best Animal Models for Testing Early Intervention in Cerebral Palsy? Front Neurol 2014; 5:258. [PMID: 25538677 PMCID: PMC4255621 DOI: 10.3389/fneur.2014.00258] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 11/21/2014] [Indexed: 11/13/2022] Open
Abstract
Interventions to treat cerebral palsy should be initiated as soon as possible in order to restore the nervous system to the correct developmental trajectory. One drawback to this approach is that interventions have to undergo exceptionally rigorous assessment for both safety and efficacy prior to use in infants. Part of this process should involve research using animals but how good are our animal models? Part of the problem is that cerebral palsy is an umbrella term that covers a number of conditions. There are also many causal pathways to cerebral palsy, such as periventricular white matter injury in premature babies, perinatal infarcts of the middle cerebral artery, or generalized anoxia at the time of birth, indeed multiple causes, including intra-uterine infection or a genetic predisposition to infarction, may need to interact to produce a clinically significant injury. In this review, we consider which animal models best reproduce certain aspects of the condition, and the extent to which the multifactorial nature of cerebral palsy has been modeled. The degree to which the corticospinal system of various animal models human corticospinal system function and development is also explored. Where attempts have already been made to test early intervention in animal models, the outcomes are evaluated in light of the suitability of the model.
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Affiliation(s)
- Gavin John Clowry
- Institute of Neuroscience, Newcastle University , Newcastle upon Tyne , UK
| | - Reem Basuodan
- Institute of Neuroscience, Newcastle University , Newcastle upon Tyne , UK
| | - Felix Chan
- Institute of Neuroscience, Newcastle University , Newcastle upon Tyne , UK
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Albertsson AM, Zhang X, Leavenworth J, Bi D, Nair S, Qiao L, Hagberg H, Mallard C, Cantor H, Wang X. The effect of osteopontin and osteopontin-derived peptides on preterm brain injury. J Neuroinflammation 2014; 11:197. [PMID: 25465048 PMCID: PMC4266908 DOI: 10.1186/s12974-014-0197-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 11/07/2014] [Indexed: 12/21/2022] Open
Abstract
Background Osteopontin (OPN) is a highly phosphorylated sialoprotein and a soluble cytokine that is widely expressed in a variety of tissues, including the brain. OPN and OPN-derived peptides have been suggested to have potential neuroprotective effects against ischemic brain injury, but their role in preterm brain injury is unknown. Methods We used a hypoxia-ischemia (HI)-induced preterm brain injury model in postnatal day 5 mice. OPN and OPN-derived peptides were given intracerebroventricularly and intranasally before HI. Brain injury was evaluated at 7 days after the insults. Results There was a significant increase in endogenous OPN mRNA and OPN protein in the mouse brain after the induction of HI at postnatal day 5. Administration of full-length OPN protein and thrombin-cleaved OPN did not affect preterm brain injury. This was demonstrated with both intracerebroventricular and intranasal administration of OPN as well as in OPN-deficient mice. Interestingly, both N134–153 and C154–198 OPN-derived peptides increased the severity of brain injury in this HI-induced preterm brain injury model. Conclusions The neuroprotective effects of OPN are age-dependent, and, in contrast to the more mature brain, OPN-derived peptides potentiate injury in postnatal day 5 mice. Intranasal administration is an efficient way of delivering drugs to the central nervous system (CNS) in neonatal mice and is likely to be an easy and noninvasive method of drug delivery to the CNS in preterm infants.
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Affiliation(s)
- Anna-Maj Albertsson
- Perinatal Center, Department of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Box 432, SE-405 30, Gothenburg, Sweden.
| | - Xiaoli Zhang
- Perinatal Center, Department of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Box 432, SE-405 30, Gothenburg, Sweden. .,Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, 7 Kangfu Front St, 450052, Zhengzhou, China.
| | - Jianmei Leavenworth
- Department of Cancer, Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, 1 Jimmy Fund Way, Boston, MA, 02115, USA. .,Department of Microbiology and Immunobiology, Division of Immunology, Harvard Medical School, 77 Ave Louis Pasteur, Boston, MA, 02115, USA.
| | - Dan Bi
- Perinatal Center, Department of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Box 432, SE-405 30, Gothenburg, Sweden. .,Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, 7 Kangfu Front St, 450052, Zhengzhou, China.
| | - Syam Nair
- Perinatal Center, Department of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Box 432, SE-405 30, Gothenburg, Sweden.
| | - Lili Qiao
- Perinatal Center, Department of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Box 432, SE-405 30, Gothenburg, Sweden. .,Department of Pediatrics, Song Jiang Central Hospital, 746 Songjiang Zhongshan West Rd, 201600, Shanghai, China.
| | - Henrik Hagberg
- Perinatal Center, Department of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Box 432, SE-405 30, Gothenburg, Sweden. .,Perinatal Center, Department of Obstetrics and Gynecology, Sahlgrenska Academy at University of Gothenburg, Journalvägen 6, 41685, Gothenburg, Sweden. .,Department of Perinatal Imaging and Health, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, SE1 7EH, UK.
| | - Carina Mallard
- Perinatal Center, Department of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Box 432, SE-405 30, Gothenburg, Sweden.
| | - Harvey Cantor
- Department of Cancer, Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, 1 Jimmy Fund Way, Boston, MA, 02115, USA. .,Department of Microbiology and Immunobiology, Division of Immunology, Harvard Medical School, 77 Ave Louis Pasteur, Boston, MA, 02115, USA.
| | - Xiaoyang Wang
- Perinatal Center, Department of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Box 432, SE-405 30, Gothenburg, Sweden. .,Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, 7 Kangfu Front St, 450052, Zhengzhou, China.
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van de Looij Y, Ginet V, Chatagner A, Toulotte A, Somm E, Hüppi PS, Sizonenko SV. Lactoferrin during lactation protects the immature hypoxic-ischemic rat brain. Ann Clin Transl Neurol 2014; 1:955-67. [PMID: 25574471 PMCID: PMC4284122 DOI: 10.1002/acn3.138] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/06/2014] [Accepted: 10/07/2014] [Indexed: 12/13/2022] Open
Abstract
Objective Lactoferrin (Lf) is an iron-binding glycoprotein secreted in maternal milk presenting anti-inflammatory and antioxidant properties. It shows efficient absorption into the brain from nutritional source. Brain injury frequently resulting from cerebral hypoxia-ischemia (HI) has a high incidence in premature infants with ensuing neurodevelopmental disabilities. We investigated the neuroprotective effect of maternal nutritional supplementation with Lf during lactation in a rat model of preterm HI brain injury using magnetic resonance imaging (MRI), brain gene, and protein expression. Methods Moderate brain HI was induced using unilateral common carotid artery occlusion combined with hypoxia (6%, 30 min) in the postnatal day 3 (P3) rat brain (24–28 weeks human equivalent). High-field multimodal MRI techniques were used to investigate the effect of maternal Lf supplementation through lactation. Expression of cytokine coding genes (TNF-α and IL-6), the prosurvival/antiapoptotic AKT protein and caspase-3 activation were also analyzed in the acute phase after HI. Results MRI analysis demonstrated reduced cortical injury in Lf rats few hours post-HI and in long-term outcome (P25). Lf reduced HI-induced modifications of the cortical metabolism and altered white matter microstructure was recovered in Lf-supplemented rats at P25. Lf supplementation significantly decreased brain TNF-α and IL-6 gene transcription, increased phosphorylated AKT levels and reduced activation of caspase-3 at 24 h post-injury. Interpretation Lf given through lactation to rat pups with cerebral HI injury shows neuroprotective effects on brain metabolism, and cerebral gray and white matter recovery. This nutritional intervention may be of high interest for the clinical field of preterm brain neuroprotection.
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Affiliation(s)
- Yohan van de Looij
- Division of Child Development and Growth, Department of Pediatrics, University of Geneva Geneva, Switzerland ; Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL) Lausanne, Switzerland
| | - Vanessa Ginet
- Division of Child Development and Growth, Department of Pediatrics, University of Geneva Geneva, Switzerland
| | - Alexandra Chatagner
- Division of Child Development and Growth, Department of Pediatrics, University of Geneva Geneva, Switzerland
| | - Audrey Toulotte
- Division of Child Development and Growth, Department of Pediatrics, University of Geneva Geneva, Switzerland
| | - Emmanuel Somm
- Division of Child Development and Growth, Department of Pediatrics, University of Geneva Geneva, Switzerland
| | - Petra S Hüppi
- Division of Child Development and Growth, Department of Pediatrics, University of Geneva Geneva, Switzerland
| | - Stéphane V Sizonenko
- Division of Child Development and Growth, Department of Pediatrics, University of Geneva Geneva, Switzerland
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238
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Cheng T, Xue X, Fu J. Effect of OLIG1 on the development of oligodendrocytes and myelination in a neonatal rat PVL model induced by hypoxia-ischemia. Mol Med Rep 2014; 11:2379-86. [PMID: 25435330 PMCID: PMC4337744 DOI: 10.3892/mmr.2014.3028] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 07/25/2014] [Indexed: 11/05/2022] Open
Abstract
OLIG1 is an oligodendrocyte (OL) transcription factor, which can contribute to the proliferation and differentiation of OLs, and the maturation of myelin. The aim of this study was to clarify the role of OLIG1 in neonatal Sprague Dawley rats with periventricular leukomalacia (PVL), induced by hypoxia‑ischemia (HI). Newborn rats in the HI group were subjected to ligation of the right carotid artery, followed by 8% oxygen delivery for 2 h, while rats in the normoxia group were only subjected to isolation of the right carotid artery, without exposure to hypoxia. Samples of brain tissue from rats in both groups were collected at 1, 3, 7, 14 and 21 days. In the HI group, observation by transmission electron microscopy (TEM) revealed OLs with a damaged nuclear membrane, cellular atrophy, deformation and necrosis, and cells in myelin with a high number of small vacuoles. A double‑label immunofluorescence assay revealed the translocation of OLIG1 from the cytoplasm to the nucleus, while western blot and reverse transcription‑quantitative polymerase chain reaction assays showed that there is a significant decrease, followed by an increase, in the gene and protein expression levels of OLIG1 and myelin basic protein (MBP). Despite the increase at the late stages of HI, the final levels of these proteins remained lower than the corresponding levels in the normoxia group. In conclusion, the decreased protein expression of OLIG1 following HI plays an important role in inhibiting the development and maturation of OLs and myelin. Although OLIG1 may, via its nuclear translocation, promote the growth and development of myelin to a certain extent, this factor fails to fully repair injured myelin.
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Affiliation(s)
- Tongfei Cheng
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Xindong Xue
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Jianhua Fu
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
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239
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Hagen MW, Riddle A, McClendon E, Gong X, Shaver D, Srivastava T, Dean JM, Bai JZ, Fowke TM, Gunn AJ, Jones DF, Sherman LS, Grafe MR, Hohimer AR, Back SA. Role of recurrent hypoxia-ischemia in preterm white matter injury severity. PLoS One 2014; 9:e112800. [PMID: 25390897 PMCID: PMC4229227 DOI: 10.1371/journal.pone.0112800] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 10/15/2014] [Indexed: 11/18/2022] Open
Abstract
Objective Although the spectrum of white matter injury (WMI) in preterm infants is shifting from cystic necrotic lesions to milder forms, the factors that contribute to this changing spectrum are unclear. We hypothesized that recurrent hypoxia-ischemia (rHI) will exacerbate the spectrum of WMI defined by markers of inflammation and molecules related to the extracellular matrix (hyaluronan (HA) and the PH20 hyaluronidase) that regulate maturation of the oligodendrocyte (OL) lineage after WMI. Methods We employed a preterm fetal sheep model of in utero moderate hypoxemia and global severe but not complete cerebral ischemia that reproduces the spectrum of human WMI. The response to rHI was compared against corresponding early or later single episodes of HI. An ordinal rating scale of WMI was compared against an unbiased quantitative image analysis protocol that provided continuous histo-pathological outcome measures for astrogliosis and microglial activation. Late oligodendrocyte progenitors (preOLs) were quantified by stereology. Analysis of hyaluronan and the hyaluronidase PH20 defined the progressive response of the extracellular matrix to WMI. Results rHI resulted in a more severe spectrum of WMI with a greater burden of necrosis, but an expanded population of preOLs that displayed reduced susceptibility to cell death. WMI from single episodes of HI or rHI was accompanied by elevated HA levels and increased labeling for PH20. Expression of PH20 in fetal ovine WMI was confirmed by RT-PCR and RNA-sequencing. Conclusions rHI is associated with an increased risk for more severe WMI with necrosis, but reduced risk for preOL degeneration compared to single episodes of HI. Expansion of the preOL pool may be linked to elevated hyaluronan and PH20.
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Affiliation(s)
- Matthew W. Hagen
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Art Riddle
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Evelyn McClendon
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Xi Gong
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Daniel Shaver
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Taasin Srivastava
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Justin M. Dean
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Ji-Zhong Bai
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Tania M. Fowke
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Alistair J. Gunn
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Daniel F. Jones
- New Zealand Genomics Ltd./Bioinformatics Institute, School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Larry S. Sherman
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, Oregon, United States of America
- Department of Cell and Developmental Biology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Marjorie R. Grafe
- Department of Pathology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - A. Roger Hohimer
- Department of Obstetrics and Gynecology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Stephen A. Back
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, United States of America
- Department of Neurology, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
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240
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Ma Q, Zhang L. Epigenetic programming of hypoxic-ischemic encephalopathy in response to fetal hypoxia. Prog Neurobiol 2014; 124:28-48. [PMID: 25450949 DOI: 10.1016/j.pneurobio.2014.11.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 08/14/2014] [Accepted: 11/02/2014] [Indexed: 12/13/2022]
Abstract
Hypoxia is a major stress to the fetal development and may result in irreversible injury in the developing brain, increased risk of central nervous system (CNS) malformations in the neonatal brain and long-term neurological complications in offspring. Current evidence indicates that epigenetic mechanisms may contribute to the development of hypoxic/ischemic-sensitive phenotype in the developing brain in response to fetal stress. However, the causative cellular and molecular mechanisms remain elusive. In the present review, we summarize the recent findings of epigenetic mechanisms in the development of the brain and their roles in fetal hypoxia-induced brain developmental malformations. Specifically, we focus on DNA methylation and active demethylation, histone modifications and microRNAs in the regulation of neuronal and vascular developmental plasticity, which may play a role in fetal stress-induced epigenetic programming of hypoxic/ischemic-sensitive phenotype in the developing brain.
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Affiliation(s)
- Qingyi Ma
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Lubo Zhang
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
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241
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Moiseev A, Doesburg SM, Herdman AT, Ribary U, Grunau RE. Altered Network Oscillations and Functional Connectivity Dynamics in Children Born Very Preterm. Brain Topogr 2014; 28:726-745. [PMID: 25370485 DOI: 10.1007/s10548-014-0416-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 10/28/2014] [Indexed: 11/26/2022]
Abstract
Structural brain connections develop atypically in very preterm children, and altered functional connectivity is also evident in fMRI studies. Such alterations in brain network connectivity are associated with cognitive difficulties in this population. Little is known, however, about electrophysiological interactions among specific brain networks in children born very preterm. In the present study, we recorded magnetoencephalography while very preterm children and full-term controls performed a visual short-term memory task. Regions expressing task-dependent activity changes were identified using beamformer analysis, and inter-regional phase synchrony was calculated. Very preterm children expressed altered regional recruitment in distributed networks of brain areas, across standard physiological frequency ranges including the theta, alpha, beta and gamma bands. Reduced oscillatory synchrony was observed among task-activated brain regions in very preterm children, particularly for connections involving areas critical for executive abilities, including middle frontal gyrus. These findings suggest that inability to recruit neurophysiological activity and interactions in distributed networks including frontal regions may contribute to difficulties in cognitive development in children born very preterm.
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Affiliation(s)
- Alexander Moiseev
- Behavioural and Cognitive Neuroscience Institute, Simon Fraser University, Vancouver, Canada.
| | - Sam M Doesburg
- Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada
- Neuroscience & Mental Health Program, Hospital for Sick Children Research Institute, Toronto, Canada
- Department of Medical Imaging, University of Toronto, Toronto, Canada
- Department of Psychology, University of Toronto, Toronto, Canada
| | - Anthony T Herdman
- Behavioural and Cognitive Neuroscience Institute, Simon Fraser University, Vancouver, Canada
- School of Audiology and Speech Sciences, University of British Columbia, Vancouver, Canada
| | - Urs Ribary
- Behavioural and Cognitive Neuroscience Institute, Simon Fraser University, Vancouver, Canada
- Department of Psychology, Simon Fraser University, Vancouver, Canada
- Department of Pediatrics, University of British Columbia, Vancouver, Canada
- Developmental Neurosciences and Child Health, Child and Family Research Institute, Vancouver, Canada
| | - Ruth E Grunau
- Department of Pediatrics, University of British Columbia, Vancouver, Canada
- Developmental Neurosciences and Child Health, Child and Family Research Institute, Vancouver, Canada
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242
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Okusa C, Oeschger F, Ginet V, Wang WZ, Hoerder-Suabedissen A, Matsuyama T, Truttmann AC, Molnár Z. Subplate in a rat model of preterm hypoxia-ischemia. Ann Clin Transl Neurol 2014; 1:679-91. [PMID: 25493282 PMCID: PMC4241795 DOI: 10.1002/acn3.97] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 07/25/2014] [Indexed: 11/25/2022] Open
Abstract
Objective Hypoxia–ischemia (HI) in preterm infants primarily leads to injuries in the cerebral white matter. However, there is growing evidence that perinatal injury in preterms can also involve other zones including the cortical gray matter. In a neonatal rat model of HI, selective vulnerability of subplate has been suggested using BrdU birth-dating methods. In this study, we aimed to investigate the neuropathological changes of the subplate and deep layers of the cortex following cerebral HI in neonatal rats with specific cell markers. Methods P2 rats underwent permanent occlusion of the right common carotid artery followed by a period of hypoxia. P8 rats were analyzed using immunohistochemistry; subplate and deep layers cells were quantified and compared with sham-operated case. Results A large variability in the extent of the cerebral injury was apparent. For the three analyzed subplate populations (Nurr1+, Cplx3+, and Ctgf+ cells), no significant cell reduction was observed in mild and moderate cases. Only in severe cases, subplate cells were strongly affected, but these injuries were always accompanied by the cell reductions in layers VI and V. Interpretation We could therefore not confirm a specific vulnerability of subplate cells compared to other deep layers or the white matter in our model.
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Affiliation(s)
- Chika Okusa
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, United Kingdom ; Institute for Advanced Medical Sciences, Hyogo College of Medicine Hyogo, Japan
| | - Franziska Oeschger
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, United Kingdom
| | - Vanessa Ginet
- Division of Neonatology, Department of Pediatrics, University Hospital Center and University of Lausanne Lausanne, Switzerland
| | - Wei-Zhi Wang
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, United Kingdom
| | | | - Tomohiro Matsuyama
- Institute for Advanced Medical Sciences, Hyogo College of Medicine Hyogo, Japan
| | - Anita C Truttmann
- Division of Neonatology, Department of Pediatrics, University Hospital Center and University of Lausanne Lausanne, Switzerland
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, United Kingdom
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243
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Ma Q, Xiong F, Zhang L. Gestational hypoxia and epigenetic programming of brain development disorders. Drug Discov Today 2014; 19:1883-96. [PMID: 25256780 DOI: 10.1016/j.drudis.2014.09.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/23/2014] [Accepted: 09/16/2014] [Indexed: 01/04/2023]
Abstract
Adverse environmental conditions faced by an individual early during its life, such as gestational hypoxia, can have a profound influence on the risk of diseases, such as neurological disorders, in later life. Clinical and preclinical studies suggest that epigenetic programming of gene expression patterns in response to maternal stress have a crucial role in the fetal origins of neurological diseases. Herein, we summarize recent studies regarding the role of epigenetic mechanisms in the developmental programming of neurological diseases in offspring, primarily focusing on DNA methylation/demethylation and miRNAs. Such information could increase our understanding of the fetal origins of adult diseases and help develop effective prevention and intervention against neurological diseases.
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Affiliation(s)
- Qingyi Ma
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Fuxia Xiong
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Lubo Zhang
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
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244
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Gallo V, Deneen B. Glial development: the crossroads of regeneration and repair in the CNS. Neuron 2014; 83:283-308. [PMID: 25033178 DOI: 10.1016/j.neuron.2014.06.010] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2014] [Indexed: 02/07/2023]
Abstract
Given the complexities of the mammalian CNS, its regeneration is viewed as the holy grail of regenerative medicine. Extraordinary efforts have been made to understand developmental neurogenesis, with the hopes of clinically applying this knowledge. CNS regeneration also involves glia, which comprises at least 50% of the cellular constituency of the brain and is involved in all forms of injury and disease response, recovery, and regeneration. Recent developmental studies have given us unprecedented insight into the processes that regulate the generation of CNS glia. Because restorative processes often parallel those found in development, we will peer through the lens of developmental gliogenesis to gain a clearer understanding of the processes that underlie glial regeneration under pathological conditions. Specifically, this review will focus on key signaling pathways that regulate astrocyte and oligodendrocyte development and describe how these mechanisms are reutilized in these populations during regeneration and repair after CNS injury.
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Affiliation(s)
- Vittorio Gallo
- Center for Neuroscience Research, Children's National Medical Center, Washington, DC 20010, USA.
| | - Benjamin Deneen
- Department of Neuroscience and Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX 77030, USA.
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245
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Vascular endothelial growth factors A and C are induced in the SVZ following neonatal hypoxia-ischemia and exert different effects on neonatal glial progenitors. Transl Stroke Res 2014; 4:158-70. [PMID: 23565129 DOI: 10.1007/s12975-012-0213-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Episodes of neonatal hypoxia-ischemia (H-I) are strongly associated with cerebral palsy and a wide spectrum of other neurological deficits in children. Two key processes required to repair damaged organs are to amplify the number of precursors capable of regenerating damaged cells and to direct their differentiation towards the cell types that need to be replaced. Since hypoxia induces vascular endothelial growth factor (VEGF) production, it is logical to predict that VEGFs are key mediators of tissue repair after H-I injury. The goal of this study was to test the hypothesis that certain VEGF isoforms increase during recovery from neonatal H-I and that they would differentially affect the proliferation and differentiation of subventricular zone (SVZ) progenitors. During the acute recovery period from H-I both VEGF-A and VEGF-C were transiently induced in the SVZ, which correlated with an increase in SVZ blood vessel diameter. These growth factors were produced by glial progenitors, astrocytes and to a lesser extent, microglia. VEGF-A promoted the production of astrocytes from SVZ glial progenitors while VEGF-C stimulated the proliferation of both early and late oligodendrocyte progenitors, which was abolished by blocking the VEGFR-3. Altogether, these results provide new insights into the signals that coordinate the reactive responses of the progenitors in the SVZ to neonatal H-I. Our studies further suggest that therapeutics that extend VEGF-C production and/or agonists that stimulate the VEGFR-3 will promote oligodendrocyte progenitor cell development to enhance myelination after perinatal brain injury.
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246
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Threlkeld SW, Gaudet CM, La Rue ME, Dugas E, Hill CA, Lim YP, Stonestreet BS. Effects of inter-alpha inhibitor proteins on neonatal brain injury: Age, task and treatment dependent neurobehavioral outcomes. Exp Neurol 2014; 261:424-33. [PMID: 25084519 DOI: 10.1016/j.expneurol.2014.07.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/10/2014] [Accepted: 07/20/2014] [Indexed: 12/18/2022]
Abstract
Hypoxic-ischemic (HI) brain injury is frequently associated with premature and/or full term birth related complications. HI injury often results in learning and processing deficits that reflect widespread damage to an extensive range of cortical and sub-cortical brain structures. Further, inflammation has been implicated in the long-term progression and severity of HI injury. Recently, inter-alpha inhibitor proteins (IAIPs) have been shown to attenuate inflammation in models of systemic infection. Importantly, preclinical studies of neonatal HI injury and neuroprotection often focus on single time windows of assessment or single behavioral domains. This approach limits translational validity, given evidence for a diverse spectrum of neurobehavioral deficits that may change across developmental windows following neonatal brain injury. Therefore, the aims of this research were to assess the effects of human IAIPs on early neocortical cell death (72h post-insult), adult regional brain volume measurements (cerebral cortex, hippocampus, striatum, corpus callosum) and long-term behavioral outcomes in juvenile (P38-50) and adult (P80+) periods across two independent learning domains (spatial and non-spatial learning), after postnatal day 7 HI injury in rats. Here, for the first time, we show that IAIPs reduce acute neocortical neuronal cell death and improve brain weight outcome 72h following HI injury in the neonatal rat. Further, these longitudinal studies are the first to show age, task and treatment dependent improvements in behavioral outcome for both spatial and non-spatial learning following systemic administration of IAIPs in neonatal HI injured rats. Finally, results also show sparing of brain regions critical for spatial and non-spatial learning in adult animals treated with IAIPs at the time of injury onset. These data support the proposal that inter-alpha inhibitor proteins may serve as novel therapeutics for brain injury associated with premature birth and/or neonatal brain injury and highlight the importance of assessing multiple ages, brain regions and behavioral domains when investigating experimental treatment efficacy.
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Affiliation(s)
- Steven W Threlkeld
- Department of Psychology, Rhode Island College, 600 Mount Pleasant Ave., Providence, RI 02904, USA.
| | - Cynthia M Gaudet
- Department of Psychology, Rhode Island College, 600 Mount Pleasant Ave., Providence, RI 02904, USA
| | - Molly E La Rue
- Department of Pediatrics, The Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, 101 Dudley Street, Providence, RI 02905, USA
| | - Ethan Dugas
- Department of Psychology, Rhode Island College, 600 Mount Pleasant Ave., Providence, RI 02904, USA
| | - Courtney A Hill
- Department of Pediatrics, The Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, 101 Dudley Street, Providence, RI 02905, USA
| | - Yow-Pin Lim
- ProThera Biologics, Inc., East Providence, RI 02914, USA
| | - Barbara S Stonestreet
- Department of Pediatrics, The Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, 101 Dudley Street, Providence, RI 02905, USA
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247
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Suryana E, Jones NM. The effects of hypoxic preconditioning on white matter damage following hypoxic-ischaemic injury in the neonatal rat brain. Int J Dev Neurosci 2014; 37:69-75. [PMID: 25009121 DOI: 10.1016/j.ijdevneu.2014.06.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/13/2014] [Accepted: 06/13/2014] [Indexed: 11/17/2022] Open
Abstract
Myelination is an essential process in human development that is carried out by oligodendrocytes in the central nervous system. Hypoxic-ischaemic (HI) brain injury can disrupt myelination by causing oxidative stress, inflammation and excitotoxicity, resulting in the loss of myelin as well as cells of the oligodendrocyte lineage. We have previously shown that hypoxic preconditioning (HP) can protect against HI injury, however, to date there have been no reports of its effects on white matter injury. Sprague-Dawley rat pups (postnatal day (P) 6) were placed into control and HP groups. On P7, pups were further separated into HI and sham surgery groups. HI pups underwent a unilateral common carotid artery occlusion and then exposed to 8% oxygen for 3h. Sham pups underwent the same procedure without occlusion and were maintained in room air. Brains were removed 5 days post-surgery for analysis. In HI-only pups there was a significant reduction in brain volume observed. Consequently, when HP was performed prior to HI, the loss of brain tissue was prevented. The number of early and late oligodendrocyte progenitors (preOLs) in the corpus callosum was unaffected by HI, however, HI reduced the amount of myelin basic protein, indicating that HI may inhibit the maturation of preOLs. Whilst HP did not affect preOL density, it was found to prevent the loss of myelin caused by HI. This indicates that HP may either protect myelin directly or possibly promote the maturation of preOLs to regenerate the lost or damaged myelin.
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Affiliation(s)
- Eurwin Suryana
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Sydney, NSW 2052, Australia
| | - Nicole M Jones
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Sydney, NSW 2052, Australia.
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248
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Development of the optic radiations and visual function after premature birth. Cortex 2014; 56:30-7. [DOI: 10.1016/j.cortex.2012.02.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 01/11/2012] [Accepted: 02/20/2012] [Indexed: 11/20/2022]
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249
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Diffusion tractography and neuromotor outcome in very preterm children with white matter abnormalities. Pediatr Res 2014; 76:86-92. [PMID: 24713814 PMCID: PMC4062577 DOI: 10.1038/pr.2014.45] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 11/21/2013] [Indexed: 11/12/2022]
Abstract
BACKGROUND Moderate-to-severe white matter abnormality (WMA) in the newborn has been shown to produce persistent disruptions in cerebral connectivity but does not universally result in neurodevelopmental disability in very preterm (VPT) children. The aims of this hypothesis-driven study were to apply diffusion imaging to: (i) examine whether bilateral WMA detected in VPT children in the newborn period can predict microstructural organization at the age of 7 y and (ii) compare corticospinal tract and corpus callosum (CC) measures in VPT children at the age of 7 y with neonatal WMA with normal vs. impaired motor functioning. METHODS Diffusion parameters of the corticospinal tract and CC were compared between VPT 7-y olds with (n = 20) and without (n = 42) bilateral WMA detected in the newborn period. For those with WMA, diffusion parameters were further examined. RESULTS Microstructural organization of corticospinal tract and CC tracts at the age of 7 y were altered in VPT children with moderate-to-severe WMA detected at term equivalent age as compared with those without injury. Furthermore, diffusion parameters differed in the CC for children with WMA categorized by motor outcome (n = 8). CONCLUSION WMA on conventional magnetic resonance imaging at term equivalent age is associated with altered microstructural organization of the corticospinal tract and CC at 7 y of age.
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250
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Chen J, Venkat P, Zacharek A, Chopp M. Neurorestorative therapy for stroke. Front Hum Neurosci 2014; 8:382. [PMID: 25018718 PMCID: PMC4072966 DOI: 10.3389/fnhum.2014.00382] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 05/14/2014] [Indexed: 12/29/2022] Open
Abstract
Ischemic stroke is responsible for many deaths and long-term disability world wide. Development of effective therapy has been the target of intense research. Accumulating preclinical literature has shown that substantial functional improvement after stroke can be achieved using subacutely administered cell-based and pharmacological therapies. This review will discuss some of the latest findings on bone marrow-derived mesenchymal stem cells (BMSCs), human umbilical cord blood cells, and off-label use of some pharmacological agents, to promote recovery processes in the sub-acute and chronic phases following stroke. This review paper also focuses on molecular mechanisms underlying the cell-based and pharmacological restorative processes, which enhance angiogenesis, arteriogenesis, neurogenesis, and white matter remodeling following cerebral ischemia as well as an analysis of the interaction/coupling among these restorative events. In addition, the role of microRNAs mediating the intercellular communication between exogenously administered cells and parenchymal cells, and their effects on the regulation of angiogenesis and neuronal progenitor cell proliferation and differentiation, and brain plasticity after stroke are described.
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Affiliation(s)
- Jieli Chen
- Department of Neurology, Henry Ford Hospital , Detroit, MI , USA
| | - Poornima Venkat
- Department of Neurology, Henry Ford Hospital , Detroit, MI , USA ; Department of Physics, Oakland University , Rochester, MI , USA
| | - Alex Zacharek
- Department of Neurology, Henry Ford Hospital , Detroit, MI , USA
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital , Detroit, MI , USA ; Department of Physics, Oakland University , Rochester, MI , USA
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