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Lim YA, Tan LS, Lee WT, Sim WL, Lv Y, Takakuni M, Saito S, Ihara M, Arumugam TV, Chen C, Wong FWS, Dawe GS. Hope for vascular cognitive impairment: Ac-YVAD-cmk as a novel treatment against white matter rarefaction. PLoS One 2024; 19:e0299703. [PMID: 38630707 PMCID: PMC11023579 DOI: 10.1371/journal.pone.0299703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 02/14/2024] [Indexed: 04/19/2024] Open
Abstract
Vascular cognitive impairment (VCI) is the second leading cause of dementia with limited treatment options, characterised by cerebral hypoperfusion-induced white matter rarefaction (WMR). Subcortical VCI is the most common form of VCI, but the underlying reasons for region susceptibility remain elusive. Recent studies employing the bilateral cortical artery stenosis (BCAS) method demonstrate that various inflammasomes regulate white matter injury and blood-brain barrier dysfunction but whether caspase-1 inhibition will be beneficial remains unclear. To address this, we performed BCAS on C57/BL6 mice to study the effects of Ac-YVAD-cmk, a caspase-1 inhibitor, on the subcortical and cortical regions. Cerebral blood flow (CBF), WMR, neuroinflammation and the expression of tight junction-related proteins associated with blood-brain barrier integrity were assessed 15 days post BCAS. We observed that Ac-YVAD-cmk restored CBF, attenuated BCAS-induced WMR and restored subcortical myelin expression. Within the subcortical region, BCAS activated the NLRP3/caspase-1/interleukin-1beta axis only within the subcortical region, which was attenuated by Ac-YVAD-cmk. Although we observed that BCAS induced significant increases in VCAM-1 expression in both brain regions that were attenuated with Ac-YVAD-cmk, only ZO-1 and occludin were observed to be significantly altered in the subcortical region. Here we show that caspase-1 may contribute to subcortical regional susceptibility in a mouse model of VCI. In addition, our results support further investigations into the potential of Ac-YVAD-cmk as a novel treatment strategy against subcortical VCI and other conditions exhibiting cerebral hypoperfusion-induced WMR.
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Affiliation(s)
- Yun-An Lim
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Li Si Tan
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Wei Thye Lee
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Wei Liang Sim
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Yang Lv
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Maki Takakuni
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Satoshi Saito
- Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
- Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo, Japan
| | - Masafumi Ihara
- Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | | | - Christopher Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Fred Wai-Shiu Wong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Gavin Stewart Dawe
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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Mechanisms of radiotherapy-associated cognitive disability in patients with brain tumours. Nat Rev Neurol 2016; 13:52-64. [PMID: 27982041 DOI: 10.1038/nrneurol.2016.185] [Citation(s) in RCA: 295] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Standard treatment of primary and metastatic brain tumours includes high-dose megavoltage-range radiation to the cranial vault. About half of patients survive >6 months, and many attain long-term control or cure. However, 50-90% of survivors exhibit disabling cognitive dysfunction. The radiation-associated cognitive syndrome is poorly understood and has no effective prevention or long-term treatment. Attention has primarily focused on mechanisms of disability that appear at 6 months to 1 year after radiotherapy. However, recent studies show that CNS alterations and dysfunction develop much earlier following radiation exposure. This finding has prompted the hypothesis that subtle early forms of radiation-induced CNS damage could drive chronic pathophysiological processes that lead to permanent cognitive decline. This Review presents evidence of acute radiation-triggered CNS inflammation, injury to neuronal lineages, accessory cells and their progenitors, and loss of supporting structure integrity. Moreover, injury-related processes initiated soon after irradiation could synergistically alter the signalling microenvironment in progenitor cell niches in the brain and the hippocampus, which is a structure critical to memory and cognition. Progenitor cell niche degradation could cause progressive neuronal loss and cognitive disability. The concluding discussion addresses future directions and potential early treatments that might reverse degenerative processes before they can cause permanent cognitive disability.
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Mueller M, Wolfs TGA, Schoeberlein A, Gavilanes AWD, Surbek D, Kramer BW. Mesenchymal stem/stromal cells-a key mediator for regeneration after perinatal morbidity? Mol Cell Pediatr 2016; 3:6. [PMID: 26869264 PMCID: PMC4751100 DOI: 10.1186/s40348-016-0034-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 01/19/2016] [Indexed: 02/07/2023] Open
Abstract
Perinatal complications in both term- and preterm-born infants are a leading cause of neonatal morbidities and mortality. Infants face different challenges in the neonatal intensive care unit with long-term morbidities such as perinatal brain injury and bronchopulmonary dysplasia being particularly devastating. While advances in perinatal medicine have improved our understanding of the pathogenesis, effective therapies to prevent and/or reduce the severity of these disorders are still lacking. The potential of mesenchymal stem/stromal cell (MSC) therapy has emerged during the last two decades, and an increasing effort is conducted to address brain- and lung-related morbidities in neonates at risk. Various studies support the notion that MSCs have protective effects. MSCs are an easy source and may be readily available after birth in a clinical setting. MSCs' mechanisms of action are diverse, including migration and homing, release of growth factors and immunomodulation, and the potential to replace injured cells. Here, we review the pathophysiology of perinatally acquired brain and lung injuries and focus on MSCs as potential candidates for therapeutic strategies summarizing preclinical and clinical evidence.
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Affiliation(s)
- Martin Mueller
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA.
- Department of Obstetrics and Gynecology, University Hospital Bern and Department of Clinical Research, University of Bern, Bern, Switzerland.
| | - Tim G A Wolfs
- Department of Pediatrics, Maastricht University Medical Center (MUMC), Maastricht, The Netherlands.
- School of Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, The Netherlands.
| | - Andreina Schoeberlein
- Department of Obstetrics and Gynecology, University Hospital Bern and Department of Clinical Research, University of Bern, Bern, Switzerland.
| | - Antonio W D Gavilanes
- Department of Pediatrics, Maastricht University Medical Center (MUMC), Maastricht, The Netherlands.
- Institute of Biomedicine, Facultad de Ciencias Médicas, Universidad Católica de Santiago de Guayaquil, Guayaquil, Ecuador.
- Department of Neuropsychology, Division Neuroscience, School of Mental Health and neuroscience (MHeNS), Maastricht University, Maastricht, The Netherlands.
| | - Daniel Surbek
- Department of Obstetrics and Gynecology, University Hospital Bern and Department of Clinical Research, University of Bern, Bern, Switzerland.
| | - Boris W Kramer
- Department of Pediatrics, Maastricht University Medical Center (MUMC), Maastricht, The Netherlands.
- School of Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, The Netherlands.
- Department of Neuropsychology, Division Neuroscience, School of Mental Health and neuroscience (MHeNS), Maastricht University, Maastricht, The Netherlands.
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Villalón H, Peñaloza G, Tuma D. TERAPIA REGENERATIVA EN NEONATOLOGÍA. REVISTA MÉDICA CLÍNICA LAS CONDES 2016. [DOI: 10.1016/j.rmclc.2016.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Wong CS, Jow GM, Kaizaki A, Fan LW, Tien LT. Melatonin ameliorates brain injury induced by systemic lipopolysaccharide in neonatal rats. Neuroscience 2014; 267:147-56. [PMID: 24613717 DOI: 10.1016/j.neuroscience.2014.02.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 02/21/2014] [Accepted: 02/21/2014] [Indexed: 11/26/2022]
Abstract
Our previous study showed that lipopolysaccharide (LPS)-induced brain injury in the neonatal rat is associated with nitrosative and oxidative stress. The present study was conducted to examine whether melatonin, an endogenous molecule with antioxidant properties, reduces systemic LPS-induced nitrosative and oxidative damage in the neonatal rat brain. Intraperitoneal (i.p.) injection of LPS (2mg/kg) was administered to Sprague-Dawley rat pups on postnatal day 5 (P5), and i.p. administration of melatonin (20mg/kg) or vehicle was performed 5min after LPS injection. Sensorimotor behavioral tests were performed 24h after LPS exposure, and brain injury was examined after these tests. The results show that systemic LPS exposure resulted in impaired sensorimotor behavioral performance, and acute brain injury, as indicated by the loss of oligodendrocyte immunoreactivity and a decrease in mitochondrial activity in the neonatal rat brain. Melatonin treatment significantly reduced LPS-induced neurobehavioral disturbances and brain damage in neonatal rats. The neuroprotective effect of melatonin was associated with attenuation of LPS-induced nitrosative and oxidative stress, as indicated by the decreased nitrotyrosine- and 4-hydroxynonenal-positive staining in the brain following melatonin and LPS exposure in neonatal rats. Further, melatonin significantly attenuated LPS-induced increases in the number of activated microglia in the neonatal rat brain. The protection provided by melatonin was also associated with a reduced number of inducible nitric oxide synthase (iNOS)+ cells, which were double-labeled with ED1 (microglia). Our results show that melatonin prevents the brain injury and neurobehavioral disturbances induced by systemic LPS exposure in neonatal rats, and its neuroprotective effects are associated with its impact on nitrosative and oxidative stress.
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Affiliation(s)
- C-S Wong
- Department of Anesthesiology, Cathay General Hospital, Taipei City, Taiwan, ROC; School of Medicine, Fu Jen Catholic University, Xinzhuang Dist., New Taipei City 24205, Taiwan, ROC
| | - G-M Jow
- School of Medicine, Fu Jen Catholic University, Xinzhuang Dist., New Taipei City 24205, Taiwan, ROC
| | - A Kaizaki
- Department of Pharmacology, Toxicology and Therapeutics, Division of Toxicology, School of Pharmacy, Showa University, Shingawa-ku, Tokyo 142-8555, Japan
| | - L-W Fan
- Department of Pediatrics, Division of Newborn Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - L-T Tien
- School of Medicine, Fu Jen Catholic University, Xinzhuang Dist., New Taipei City 24205, Taiwan, ROC.
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Liu XB, Shen Y, Plane JM, Deng W. Vulnerability of premyelinating oligodendrocytes to white-matter damage in neonatal brain injury. Neurosci Bull 2013; 29:229-38. [PMID: 23456565 DOI: 10.1007/s12264-013-1311-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 12/24/2012] [Indexed: 01/25/2023] Open
Abstract
Premature birth is a significant economic and public health burden, and its incidence is rising. Periventricular leukomalacia (PVL) is the predominant form of brain injury in premature infants and the leading cause of cerebral palsy. PVL is characterized by selective white-matter damage with prominent oligodendroglial injury. The maturation-dependent vulnerability of developing and premyelinating oligodendrocytes to excitotoxic, oxidative, and inflammatory forms of injury is a major factor in the pathogenesis of PVL. Recent studies using mouse models of PVL reveal that synapses between axons and developing oligodendrocytes are quickly and profoundly damaged in immature white matter. Axon-glia synapses are highly vulnerable to white-matter injury in the developing brain, and the loss of synapses between axons and premyelinating oligodendrocytes occurs before any cellular loss in the immature white matter. Microglial activation and astrogliosis play important roles in triggering white-matter injury. Impairment of white-matter development and function in the neonatal period contributes critically to functional and behavioral deficits. Preservation of the integrity of the white matter is likely key in the treatment of PVL and subsequent neurological consequences and disabilities.
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Affiliation(s)
- Xiao-Bo Liu
- Department of Biochemistry and Molecular Medicine, Institute for Pediatric Regenerative Medicine, School of Medicine, University of California at Davis, Sacramento, CA 95817, USA
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Bierhals T, Maddukuri SB, Kutsche K, Girisha KM. Expanding the phenotype associated with 17q12 duplication: Case report and review of the literature. Am J Med Genet A 2013; 161A:352-9. [DOI: 10.1002/ajmg.a.35730] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Accepted: 10/01/2012] [Indexed: 12/29/2022]
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Phillips AW, Falahati S, DeSilva R, Shats I, Marx J, Arauz E, Kerr DA, Rothstein JD, Johnston MV, Fatemi A. Derivation of glial restricted precursors from E13 mice. J Vis Exp 2012:3462. [PMID: 22760029 PMCID: PMC3399460 DOI: 10.3791/3462] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
This is a protocol for derivation of glial restricted precursor (GRP) cells from the spinal cord of E13 mouse fetuses. These cells are early precursors within the oligodendrocytic cell lineage. Recently, these cells have been studied as potential source for restorative therapies in white matter diseases. Periventricular leukomalacia (PVL) is the leading cause of non-genetic white matter disease in childhood and affects up to 50% of extremely premature infants. The data suggest a heightened susceptibility of the developing brain to hypoxia-ischemia, oxidative stress and excitotoxicity that selectively targets nascent white matter. Glial restricted precursors (GRP), oligodendrocyte progenitor cells (OPC) and immature oligodendrocytes (preOL) seem to be key players in the development of PVL and are the subject of continuing studies. Furthermore, previous studies have identified a subset of CNS tissue that has increased susceptibility to glutamate excitotoxicity as well as a developmental pattern to this susceptibility. Our laboratory is currently investigating the role of oligodendrocyte progenitors in PVL and use cells at the GRP stage of development. We utilize these derived GRP cells in several experimental paradigms to test their response to select stresses consistent with PVL. GRP cells can be manipulated in vitro into OPCs and preOL for transplantation experiments with mouse PVL models and in vitro models of PVL-like insults including hypoxia-ischemia. By using cultured cells and in vitro studies there would be reduced variability between experiments which facilitates interpretation of the data. Cultured cells also allows for enrichment of the GRP population while minimizing the impact of contaminating cells of non-GRP phenotype.
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Affiliation(s)
- André W Phillips
- Hugo W. Moser Research Institute at Kennedy Krieger, Johns Hopkins University.
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Kapitanović Vidak H, Catela Ivković T, Jokić M, Spaventi R, Kapitanović S. The association between proinflammatory cytokine polymorphisms and cerebral palsy in very preterm infants. Cytokine 2012; 58:57-64. [PMID: 22266275 DOI: 10.1016/j.cyto.2011.12.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 11/20/2011] [Accepted: 12/24/2011] [Indexed: 12/14/2022]
Abstract
Cerebral palsy (CP) is a nonprogressive motor disorder caused by white matter damage in the developing brain and is often accompanied with cognitive and sensory disabilities. The risk of CP is higher among infants born preterm than in more mature infants. Intrauterine infection/inflammation, activation of the cytokine network and elevated levels of proinflammatory cytokines in neonatal blood or in amniotic fluid to which the preterm infant is exposed, has been identified as the most common cause of preterm delivery, periventricular leukomalacia (PVL) and CP. The aim of our study was to evaluate the possible association of four TNFα promoter single nucleotide polymorphisms (SNPs) (-1031 T/C, -857 C/T, -308 G/A and -238 G/A), two IL1β SNPs (-511 C/T and +3954 C/T) and one IL6 (-174 C/G) polymorphism with susceptibility to CP in very preterm infants. Statistically significant association between TNFα -1031 T/C high expression genotypes (TC and CC) (OR, 2.339; p=0.016) as well as between TNFα -1031 C high expression allele (OR, 2.065; p=0.013) and risk of CP was observed. In addition, statistically significant association was found between TNFα TC, CC, GG, GG -1031/-857/-308/-238 genotypes combination (OR, 3.286; p=0.034) and risk of CP. Statistically significant association between IL1β TT, CC -511/+3954 genotypes combination and risk of CP (OR, 4.000; p=0.027) was also found. In CP patients with cystic PVL (cPVL) statistically significant association was found between TNFα -1031 T/C high expression genotypes (TC and CC) (OR, 2.361; p=0.038), IL1β -511 C/T high expression genotype TT (OR, 3.215; p=0.030) as well as IL1β -511 T high expression allele (OR, 1.956; p=0.019) and risk of CP. Statistically significant association was also found in patients with cPVL between TNFα TC, CC, GG, GG -1031/-857/-308/-238 genotypes combination (OR, 4.107; p=0.024), as well as IL1β TT, CC -511/+3954 genotypes combination (OR, 7.333; p=0.005) and risk of CP. Our results suggest the role of TNFα and IL1β polymorphisms which have previously been associated with higher circulating levels of these cytokines in genetic susceptibility to white matter damage and consequently CP in very preterm infants.
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Affiliation(s)
- Helena Kapitanović Vidak
- Special Hospital for Children with Neurodevelopmental and Motor Difficulties, Goljak 2, Zagreb, Croatia
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Li S, Lin W, Tchantchou F, Lai R, Wen J, Zhang Y. Protein kinase C mediates peroxynitrite toxicity to oligodendrocytes. Mol Cell Neurosci 2011; 48:62-71. [PMID: 21708260 DOI: 10.1016/j.mcn.2011.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 05/16/2011] [Accepted: 06/08/2011] [Indexed: 12/12/2022] Open
Abstract
Peroxynitrite has been suggested to be the potent oxidant causing toxicity to neurons and oligodendrocytes (OLs). Our previous studies have illustrated that intracellular zinc liberation contributes to peroxynitrite toxicity to mature OLs. In this study, we further investigated the signaling pathways involved in this event and identified protein kinase C (PKC) as an important early signaling molecule. We found that a non-selective PKC inhibitor bisindolylmaleimide-1 blocked OL toxicity induced by a peroxynitrite generator SIN-1 and exogenous zinc. The protective effects were due to its inhibition on ERK1/2 phosphorylation and ROS generation. The same phenomenon was also observed in OLs following prolonged treatment with phorbol 12 myristate 13 acetate (PMA), which downregulates the conventional and the novel PKC isoforms (cPKCs and nPKCs). To determine the role of specific PKC isoforms, we found that a specific nPKC inhibitor rottlerin significantly reduced SIN-1- or zinc-induced toxicity, whereas Go6976, a cPKC inhibitor, reduced OL toxicity triggered by zinc, but not by SIN-1 at high concentrations. Rottlerin was more potent than Go6976 to attenuate ERK1/2 phosphorylation and ROS generation induced by SIN-1 or zinc. Surprisingly, zinc only induced phosphorylation of PKCθ, but not PKCδ. Knockdown of PKCθ using lentiviral shRNA attenuated SIN-1- or zinc-induced toxicity. These results suggest that PKCθ might be the major PKC isoform involved in peroxynitrite and zinc toxicity to mature OLs, and provide a rationale for development of specific inhibitors of PKCθ in the treatment of multiple sclerosis and other neurodegenerative diseases, in which peroxynitrite formation plays a pathogenic role.
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Affiliation(s)
- Shihe Li
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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Parker-Athill EC, Tan J. Maternal immune activation and autism spectrum disorder: interleukin-6 signaling as a key mechanistic pathway. Neurosignals 2010; 18:113-28. [PMID: 20924155 DOI: 10.1159/000319828] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 07/30/2010] [Indexed: 12/29/2022] Open
Abstract
An emerging area of research in autism spectrum disorder (ASD) is the role of prenatal exposure to inflammatory mediators during critical developmental periods. Epidemiological data has highlighted this relationship showing significant correlations between prenatal exposure to pathogens, including influenza, and the occurrence of ASD. Although there has not been a definitive molecular mechanism established, researchers have begun to investigate this relationship as animal models of maternal infection have support- ed epidemiological findings. Several groups utilizing these animal models have found that activation of the maternal immune system, termed maternal immune activation (MIA), and more specifically the exposure of the developing fetus to maternal cytokines precipitate the neurological, immunological and behavioral abnormalities observed in the offspring of these animals. These abnormalities have correlated with clinical findings of immune dysregulation, neurological and behavioral abnormalities in some autistic individuals. Additionally, researchers have observed genetic variations in these models in genes which regulate neurological and immunological development, similar to what is observed clinically in ASD. Altogether, the role of MIA and cytokine dysregulation, as a key mediator in the neuropathological, behavioral and possibly genetic irregularities observed clinically in autism are important factors that warrant further investigation.
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Affiliation(s)
- E Carla Parker-Athill
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center, University of South Florida, Tampa, FL 33613, USA
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Fan X, Heijnen CJ, van der Kooij MA, Groenendaal F, van Bel F. The role and regulation of hypoxia-inducible factor-1alpha expression in brain development and neonatal hypoxic-ischemic brain injury. ACTA ACUST UNITED AC 2009; 62:99-108. [PMID: 19786048 DOI: 10.1016/j.brainresrev.2009.09.006] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Revised: 09/17/2009] [Accepted: 09/19/2009] [Indexed: 01/10/2023]
Abstract
During neonatal hypoxic-ischemic brain injury, activation of transcription of a series of genes is induced to stimulate erythropoiesis, anti-apoptosis, apoptosis, necrosis and angiogenesis. A key factor mediating these gene transcriptions is hypoxia-inducible factor-1alpha (HIF-1alpha). During hypoxia, HIF-1alpha protein is stabilized and heterodimerizes with HIF-1beta to form HIF-1, subsequently regulating the expression of target genes. HIF-1alpha participates in early brain development and proliferation of neuronal precursor cells. Under pathological conditions, HIF-1alpha is known to play an important role in neonatal hypoxic-ischemic brain injury: on the one hand, HIF-1alpha has neuroprotective effects whereas it can also have neurotoxic effects. HIF-1alpha regulates the transcription of erythropoietin (EPO), which induces several pathways associated with neuroprotection. HIF-1alpha also promotes the expression of vascular endothelial cell growth factor (VEGF), which is related to neovascularization in hypoxic-ischemic brain areas. In addition, HIF-1alpha has an anti-apoptotic effect by increasing the expression of anti-apoptotic factors such as EPO during mild hypoxia. The neurotoxic effects of HIF-1alpha are represented by its participation in the apoptotic process by increasing the stability of the tumor suppressor protein p53 during severe hypoxia. Moreover, HIF-1alpha plays a role in cell necrosis, by interacting with calcium and calpain. HIF-1alpha can also exacerbate brain edema via increasing the permeability of the blood-brain barrier (BBB). Given these properties, HIF-1alpha has both neuroprotective and neurotoxic effects after hypoxia-ischemia. These events are cell type specific and related to the severity of hypoxia. Unravelling of the complex functions of HIF-1alpha may be important when designing neuroprotective therapies for hypoxic-ischemic brain injury.
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Affiliation(s)
- Xiyong Fan
- Department of Neonatology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan, The Netherlands
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Expanded repertoire of AAV vector serotypes mediate unique patterns of transduction in mouse brain. Mol Ther 2008; 16:1710-8. [PMID: 18714307 DOI: 10.1038/mt.2008.166] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A wide diversity of adeno-associated virus (AAV) structural proteins uncovered from latent genomes in primate tissue has expanded the number of AAV vector serotypes, which can potentially confer unique cell tropism to the vector. We evaluated 17 of these vectors in the mouse brain using green fluorescent protein (GFP) as a reporter gene. A rapid initial evaluation was performed by neonatal lateral ventricle injections. Vectors made with capsids hu.32, hu.37, pi.2, hu.11, rh.8, hu.48R3, and AAV9 for comparison were selected for further analysis based on their ability to transduce large numbers of cells and result in novel patterns of cell transduction. These vectors were injected into adult brains in four major structures (cortex, striatum, hippocampus, and thalamus), and all were found to transduce neurons. In addition, hu.32, hu.11, pi.2, hu.48R3, and rh.8 resulted in GFP expression in some astrocytes or oligodendrocytes. AAVs rh.8, pi.2, hu.32, and hu.11 also appeared to result in neuronal transport of the vector genome. Vector transport was studied by a single unilateral injection into the hippocampus and vector genome was found in projection sites of the hippocampus. These unique patterns of cell transduction expand the potential repertoire for targeting AAV vectors to selected subsets of brain cells.
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Platelet-derived growth factor promotes repair of chronically demyelinated white matter. J Neuropathol Exp Neurol 2007; 66:975-88. [PMID: 17984680 DOI: 10.1097/nen.0b013e3181587d46] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In multiple sclerosis, remyelination becomes limited after repeated or prolonged episodes of demyelination. To test the effect of platelet-derived growth factor-A (PDGF-A) in recovery from chronic demyelination we induced corpus callosum demyelination using cuprizone treatment in hPDGF-A transgenic (tg) mice with the human PDGF-A gene under control of an astrocyte-specific promoter. After chronic demyelination and removal of cuprizone from the diet, remyelination and oligodendrocyte density improved significantly in hPDGF-A tg mice compared with wild-type mice. In hPDGF-A tg mice, oligodendrocyte progenitor density and proliferation values were increased in the corpus callosum during acute demyelination but not during chronic demyelination or the subsequent recovery period, compared with hPDGF-A tg mice without cuprizone or to treatment-matched wild-type mice. Proliferation within the subventricular zone and subcallosal zone was elevated throughout cuprizone treatment but was not different between hPDGF-A tg and wild-type mice. Importantly, hPDGF-A tg mice had reduced apoptosis in the corpus callosum during the recovery period after chronic demyelination. Therefore, PDGF-A may support oligodendrocyte generation and survival to promote remyelination of chronic lesions. Furthermore, preventing oligodendrocyte apoptosis may be important not only during active demyelination but also for supporting the generation of new oligodendrocytes to remyelinate chronic lesions.
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Cogulu O, Aykut A, Kutukculer N, Ozkinay C, Ozkinay F. Two cases of macrocephaly and immune deficiency. Clin Dysmorphol 2007; 16:81-84. [PMID: 17351349 DOI: 10.1097/mcd.0b013e3280464ee6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Macrocephaly describes a head circumference greater than two standard deviations above the mean and is a feature of a number of genetic syndromes. Here we report on two patients with microcephaly, immune deficiency and anemia. In addition, one case had periventricular leukomalacia and the other case had myelinisation delay in periventricular white matter development. These cases may represent a distinct new syndrome.
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Affiliation(s)
- Ozgur Cogulu
- Departments of Pediatrics Medical Genetics, Faculty of Medicine, Ege University, Izmir, Turkey
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