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Pagnin M, Kondos-Devcic D, Chincarini G, Cumberland A, Richardson SJ, Tolcos M. Role of thyroid hormones in normal and abnormal central nervous system myelination in humans and rodents. Front Neuroendocrinol 2021; 61:100901. [PMID: 33493504 DOI: 10.1016/j.yfrne.2021.100901] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/07/2021] [Accepted: 01/16/2021] [Indexed: 12/13/2022]
Abstract
Thyroid hormones (THs) are instrumental in promoting the molecular mechanisms which underlie the complex nature of neural development and function within the central nervous system (CNS) in vertebrates. The key neurodevelopmental process of myelination is conserved between humans and rodents, of which both experience peak fetal TH concentrations concomitant with onset of myelination. The importance of supplying adequate levels of THs to the myelin producing cells, the oligodendrocytes, for promoting their maturation is crucial for proper neural function. In this review we examine the key TH distributor and transport proteins, including transthyretin (TTR) and monocarboxylate transporter 8 (MCT8), essential for supporting proper oligodendrocyte and myelin health; and discuss disorders with impaired TH signalling in relation to abnormal CNS myelination in humans and rodents. Furthermore, we explore the importance of using novel TH analogues in the treatment of myelination disorders associated with abnormal TH signalling.
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Affiliation(s)
- Maurice Pagnin
- School of Health and Biomedical Sciences, RMIT University, Bundoora 3083, Australia
| | - Delphi Kondos-Devcic
- School of Health and Biomedical Sciences, RMIT University, Bundoora 3083, Australia
| | - Ginevra Chincarini
- School of Health and Biomedical Sciences, RMIT University, Bundoora 3083, Australia
| | - Angela Cumberland
- School of Health and Biomedical Sciences, RMIT University, Bundoora 3083, Australia
| | | | - Mary Tolcos
- School of Health and Biomedical Sciences, RMIT University, Bundoora 3083, Australia.
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Kratzer I, Ek J, Stolp H. The molecular anatomy and functions of the choroid plexus in healthy and diseased brain. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183430. [PMID: 32750317 DOI: 10.1016/j.bbamem.2020.183430] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 07/18/2020] [Accepted: 07/20/2020] [Indexed: 01/16/2023]
Abstract
The choroid plexus (CP) is located in the ventricular system of the brain (one in each ventricle), and the CP epithelial cells form an important barrier between the blood and the cerebrospinal fluid (CSF). Their main function comprises CSF secretion, maintenance of brain homeostasis, signalling, and forming a neuroprotective barrier against harmful external and internal compounds. The CPs mature early and demonstrate expressional changes of barrier-specific genes and proteins related to location and developmental stage of the CP. Important proteins for the barrier function include tight junction proteins, numerous transporters and enzymes. Natural senescence leads to structural changes in the CP cells and reduced or loss of function, while further loss of CP function and changes in immune status may be relevant in neurodegenerative diseases such as Alzheimer's disease and Multiple Sclerosis. Neuroprotective genes expressed at CPs may be unexplored targets for new therapies for neurodegenerative diseases.
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Affiliation(s)
- Ingrid Kratzer
- FLUID Team, Lyon Neurosciences Research Center, INSERM U1028 CNRS UMR 5292, University Claude Bernard Lyon 1, 69008 Lyon, France; Friedensgasse 3, 8010 Graz, Austria.
| | - Joakim Ek
- Department of Physiology, Institute of Neuroscience and Physiology, University of Gothenburg, Medicinaregatan 11, Box 432, 40530 Göteborg, Sweden.
| | - Helen Stolp
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London NW0 1TU, UK.
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DISDIER C, STONESTREET BS. Hypoxic-ischemic-related cerebrovascular changes and potential therapeutic strategies in the neonatal brain. J Neurosci Res 2020; 98:1468-1484. [PMID: 32060970 PMCID: PMC7242133 DOI: 10.1002/jnr.24590] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 01/20/2020] [Accepted: 01/28/2020] [Indexed: 12/11/2022]
Abstract
Perinatal hypoxic-ischemic (HI)-related brain injury is an important cause of morbidity and long-standing disability in newborns. The only currently approved therapeutic strategy available to reduce brain injury in the newborn is hypothermia. Therapeutic hypothermia can only be used to treat HI encephalopathy in full-term infants and survivors remain at high risk for a wide spectrum of neurodevelopmental abnormalities as a result of residual brain injury. Therefore, there is an urgent need for adjunctive therapeutic strategies. Inflammation and neurovascular damage are important factors that contribute to the pathophysiology of HI-related brain injury and represent exciting potential targets for therapeutic intervention. In this review, we address the role of each component of the neurovascular unit (NVU) in the pathophysiology of HI-related injury in the neonatal brain. Disruption of the blood-brain barrier (BBB) observed in the early hours after an HI-related event is associated with a response at the basal lamina level, which comprises astrocytes, pericytes, and immune cells, all of which could affect BBB function to further exacerbate parenchymal injury. Future research is required to determine potential drugs that could prevent or attenuate neurovascular damage and/or augment repair. However, some studies have reported beneficial effects of hypothermia, erythropoietin, stem cell therapy, anti-cytokine therapy and metformin in ameliorating several different facets of damage to the NVU after HI-related brain injury in the perinatal period.
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Affiliation(s)
- Clémence DISDIER
- Department of Pediatrics, Women & Infants Hospital of Rhode Island, The Alpert Medical School of Brown University, Providence, RI 02905, USA
| | - Barbara S STONESTREET
- Department of Pediatrics, Women & Infants Hospital of Rhode Island, The Alpert Medical School of Brown University, Providence, RI 02905, USA
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Mallard C, Ek CJ, Vexler ZS. The myth of the immature barrier systems in the developing brain: role in perinatal brain injury. J Physiol 2018. [PMID: 29528501 DOI: 10.1113/jp274938] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Central nervous system homeostasis is maintained by cellular barriers that protect the brain from external environmental changes and protect the CNS from harmful molecules and pathogens in the blood. Historically, for many years these barriers were thought of as immature, with limited functions, during brain development. In this review, we will present advances in the understanding of the barrier systems during development and evidence to show that in fact the barriers serve many important neurodevelopmental functions and that fetal and newborn brains are well protected. We will also discuss how ischaemic injury or systemic inflammation may breach the integrity of the barriers in the developing brain.
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Affiliation(s)
- Carina Mallard
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - C Joakim Ek
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Zinaida S Vexler
- Department of Neurology, University California San Francisco, USA
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The great barrier belief: The blood–brain barrier and considerations for juvenile toxicity studies. Reprod Toxicol 2017. [DOI: 10.1016/j.reprotox.2017.06.043] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Effects of therapeutic hypothermia on white matter injury from murine neonatal hypoxia-ischemia. Pediatr Res 2017; 82:518-526. [PMID: 28561815 PMCID: PMC5570671 DOI: 10.1038/pr.2017.75] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 03/06/2017] [Indexed: 12/20/2022]
Abstract
BackgroundTherapeutic hypothermia (TH) is the standard of care for neonates with hypoxic-ischemic encephalopathy, but it is not fully protective in the clinical setting. Hypoxia-ischemia (HI) may cause white matter injury (WMI), leading to neurological and cognitive dysfunction.MethodsP9 mice were subjected to HI as previously described. Pups underwent 3.5 h of systemic hypothermia or normothermia. Cresyl violet and Perl's iron staining for histopathological scoring of brain sections was completed blindly on all brains. Immunocytochemical (ICC) staining for myelin basic protein (MBP), microglia (Iba1), and astrocytes (glia fibrillary acidic protein (GFAP)) was performed on adjacent sections. Volumetric measurements of MBP coverage were used for quantitative analysis of white matter.ResultsTH provided neuroprotection by injury scoring for the entire group (n=44; P<0.0002). ICC analysis of a subset of brains showed that the lateral caudate was protected from WMI (P<0.05). Analysis revealed decreased GFAP and Iba1 staining in hippocampal regions, mostly CA2/CA3. GFAP and Iba1 directly correlated with injury scores of normothermic brains.ConclusionTH reduced injury, and qualitative data suggest that hippocampus and lateral caudate are protected from HI. Mildly injured brains may better show the benefits of TH. Overall, these data indicate regional differences in WMI susceptibility and inflammation in a P9 murine HI model.
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Lai JCY, Rocha-Ferreira E, Ek CJ, Wang X, Hagberg H, Mallard C. Immune responses in perinatal brain injury. Brain Behav Immun 2017; 63:210-223. [PMID: 27865947 DOI: 10.1016/j.bbi.2016.10.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 10/28/2016] [Accepted: 10/30/2016] [Indexed: 12/13/2022] Open
Abstract
The perinatal period has often been described as immune deficient. However, it has become clear that immune responses in the neonate following exposure to microbes or as a result of tissue injury may be substantial and play a role in perinatal brain injury. In this article we will review the immune cell composition under normal physiological conditions in the perinatal period, both in the human and rodent. We will summarize evidence of the inflammatory responses to stimuli and discuss how neonatal immune activation, both in the central nervous system and in the periphery, may contribute to perinatal hypoxic-ischemic brain injury.
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Affiliation(s)
- Jacqueline C Y Lai
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden
| | - Eridan Rocha-Ferreira
- Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden
| | - C Joakim Ek
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden
| | - Xiaoyang Wang
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden
| | - Henrik Hagberg
- Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden
| | - Carina Mallard
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 432, 405 30 Gothenburg, Sweden.
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The choroid plexus as a sex hormone target: Functional implications. Front Neuroendocrinol 2017; 44:103-121. [PMID: 27998697 DOI: 10.1016/j.yfrne.2016.12.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/25/2016] [Accepted: 12/12/2016] [Indexed: 12/21/2022]
Abstract
The choroid plexuses (CPs) are highly vascularized branched structures that protrude into the ventricles of the brain, and form a unique interface between the blood and the cerebrospinal fluid (CSF). In recent years, novel functions have been attributed to this tissue such as in immune and chemical surveillance of the central nervous system, brain development, adult neurogenesis and circadian rhythm regulation. Sex hormones (SH) are widely recognized as modulators in several neurodegenerative diseases, and there is evidence that estrogens and androgens regulate several fundamental biological functions in the CPs. Therefore, SH are likely to affect the composition of the CSF impacting on brain homeostasis. This review will look at implications of the CPs' sex-related specificities.
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