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Shmakova AA, Rysenkova KD, Ivashkina OI, Gruzdeva AM, Klimovich PS, Popov VS, Rubina KA, Anokhin KV, Tkachuk VA, Semina EV. Early Induction of Neurotrophin Receptor and miRNA Genes in Mouse Brain after Pentilenetetrazole-Induced Neuronal Activity. BIOCHEMISTRY. BIOKHIMIIA 2021; 86:1326-1341. [PMID: 34903157 DOI: 10.1134/s0006297921100138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 06/21/2021] [Accepted: 06/30/2021] [Indexed: 06/14/2023]
Abstract
Neurotrophin receptors regulate neuronal survival and network formation, as well as synaptic plasticity in the brain via interaction with their ligands. Here, we examined early changes in the expression of neurotrophin receptor genes Ntk1 (TrkA), Ntrk2 (TrkB), Ntrk3 (TrkC), Ngfr (p75NTR) and miRNAs that target theses gens in the mouse brain after induction of seizure activity by pentylenetetrazol. We found that expression of Ntrk3 and Ngfr was upregulated in the cortex and the hippocampus 1-3 hours after the seizures, while Ntrk2 expression increased after 3-6 hours in the anterior cortex and after 1 and 6 hours in the hippocampus. At the same time, the ratio of Bcl-2/Bax signaling proteins increased in the anterior and posterior cortex, but not in the hippocampus, suggesting the activation of anti-apoptotic signaling. Expression of miRNA-9 and miRNA-29a, which were predicted to target Ntrk3, was upregulated in the hippocampus 3 hours after pentylenetetrazol injection. Therefore, early cellular response to seizures in the brain includes induction of the Ntrk2, Ntrk3, Ngfr, miRNA-9, and miRNA-29a expression, as well as activation of Bcl-2 and Bax signaling pathways, which may characterize them as important mediators of neuronal adaptation and survival upon induction of the generalized brain activity.
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Affiliation(s)
- Anna A Shmakova
- Faculty of Medicine, Lomonosov Moscow State University, Moscow, 119192, Russia
- Institute of Experimental Cardiology, National Cardiology Research Center of the Ministry of Health of the Russian Federation, Moscow, 121552, Russia
| | - Karina D Rysenkova
- Faculty of Medicine, Lomonosov Moscow State University, Moscow, 119192, Russia
- Institute of Experimental Cardiology, National Cardiology Research Center of the Ministry of Health of the Russian Federation, Moscow, 121552, Russia
| | - Olga I Ivashkina
- Institute for Advanced Brain Studies, Lomonosov Moscow State University, Moscow, 119192, Russian Federation
- Anokhin Research Institute of Normal Physiology, Moscow, 125315, Russia
- Kurchatov Institute National Research Center, Moscow, 123182, Russia
| | - Anna M Gruzdeva
- Institute for Advanced Brain Studies, Lomonosov Moscow State University, Moscow, 119192, Russian Federation
| | - Polina S Klimovich
- Faculty of Medicine, Lomonosov Moscow State University, Moscow, 119192, Russia
- Institute of Experimental Cardiology, National Cardiology Research Center of the Ministry of Health of the Russian Federation, Moscow, 121552, Russia
| | - Vladimir S Popov
- Faculty of Medicine, Lomonosov Moscow State University, Moscow, 119192, Russia
| | - Kseniya A Rubina
- Faculty of Medicine, Lomonosov Moscow State University, Moscow, 119192, Russia
| | - Konstantin V Anokhin
- Institute for Advanced Brain Studies, Lomonosov Moscow State University, Moscow, 119192, Russian Federation.
- Anokhin Research Institute of Normal Physiology, Moscow, 125315, Russia
| | - Vsevolod A Tkachuk
- Faculty of Medicine, Lomonosov Moscow State University, Moscow, 119192, Russia
- Institute of Experimental Cardiology, National Cardiology Research Center of the Ministry of Health of the Russian Federation, Moscow, 121552, Russia
| | - Ekaterina V Semina
- Faculty of Medicine, Lomonosov Moscow State University, Moscow, 119192, Russia.
- Institute of Experimental Cardiology, National Cardiology Research Center of the Ministry of Health of the Russian Federation, Moscow, 121552, Russia
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Shmakova AA, Balatskiy AV, Kulebyakina MA, Schaub T, Karagyaur MN, Kulebyakin KY, Rysenkova KD, Tarabykin VS, Tkachuk VA, Semina EV. Urokinase Receptor uPAR Overexpression in Mouse Brain Stimulates the Migration of Neurons into the Cortex during Embryogenesis. Russ J Dev Biol 2021. [DOI: 10.1134/s1062360421010069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Ma X, Qiu S. Control of cortical synapse development and plasticity by MET receptor tyrosine kinase, a genetic risk factor for autism. J Neurosci Res 2019; 98:2115-2129. [PMID: 31746037 DOI: 10.1002/jnr.24542] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 10/04/2019] [Accepted: 10/04/2019] [Indexed: 12/27/2022]
Abstract
The key developmental milestone events of the human brain, such as neurogenesis, synapse formation, maturation, and plasticity, are determined by a myriad of molecular signaling events, including those mediated by a number of receptor tyrosine kinases (RTKs) and their cognate ligands. Aberrant or mistimed brain development and plasticity can lead to maladaptive changes, such as dysregulated synaptic connectivity and breakdown of circuit functions necessary for cognition and adaptive behaviors, which are hypothesized pathophysiologies of many neurodevelopmental and neuropsychiatric disorders. Here we review recent literature that supports autism spectrum disorder as a likely result of aberrant synapse development due to mistimed maturation and plasticity. We focus on MET RTK, a prominent genetic risk factor for autism, and discuss how a pleiotropic molecular signaling system engaged by MET exemplifies a genetic program that controls cortical circuit development and plasticity by modulating the anatomical and functional connectivity of cortical circuits, thus conferring genetic risk for neurodevelopmental disorders.
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Affiliation(s)
- Xiaokuang Ma
- Department of Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Shenfeng Qiu
- Department of Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
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Shmakova AA, Rubina KA, Rysenkova KD, Gruzdeva AM, Ivashkina OI, Anokhin KV, Tkachuk VA, Semina EV. Urokinase receptor and tissue plasminogen activator as immediate-early genes in pentylenetetrazole-induced seizures in the mouse brain. Eur J Neurosci 2019; 51:1559-1572. [PMID: 31587391 DOI: 10.1111/ejn.14584] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 08/13/2019] [Accepted: 09/20/2019] [Indexed: 11/30/2022]
Abstract
Epileptogenesis progressively leads to the rearrangement of normal neuronal networks into more excitable ones and can be viewed as a form of neuroplasticity, the molecular mechanisms of which still remain obscure. Here, we studied pentylenetetrazole seizure-induced regulation of genes for plasminogen activator system in the mouse brain. We found that expression of tissue plasminogen activator (tPA) and urokinase receptor (uPAR) mRNA was strongly increased in the mouse cerebral cortex, hippocampus, striatum and amygdala as early as 3 hr after pentylenetetrazole seizures. Such early activity-induced expression of uPAR in the central nervous system has not been demonstrated before. uPAR mRNA accumulation was followed by elevation of uPAR protein, indicating a complete transcription-translation process. Both tPA gene induction and uPAR gene induction were independent of the protein synthesis, suggesting that they are regulated by neural activity as immediate-early genes. In contrast to tPA and uPAR genes, the expression of which returned to the basal level 6 hr following seizures, urokinase and plasminogen activator inhibitor-1 gene expression showed a delayed activation only at 3 days after seizures. In conclusion, our results suggest an important sensitivity of the brain plasminogen activator system to seizure activity which raises the question of its role in activity-dependent neural tissue remodeling in pathological and normal conditions.
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Affiliation(s)
- Anna A Shmakova
- Laboratory of Gene and Cell Technologies, Faculty of Medicine, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Kseniya A Rubina
- Laboratory of Gene and Cell Technologies, Faculty of Medicine, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Karina D Rysenkova
- Laboratory of Gene and Cell Technologies, Faculty of Medicine, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Anna M Gruzdeva
- Institute for Advanced Brain Studies, Lomonosov Moscow State University, Moscow, Russian Federation.,Laboratory for Neurobiology of Memory, P.K. Anokhin Research Institute of Normal Physiology, Moscow, Russian Federation
| | - Olga I Ivashkina
- Institute for Advanced Brain Studies, Lomonosov Moscow State University, Moscow, Russian Federation.,Laboratory for Neurobiology of Memory, P.K. Anokhin Research Institute of Normal Physiology, Moscow, Russian Federation
| | - Konstantin V Anokhin
- Institute for Advanced Brain Studies, Lomonosov Moscow State University, Moscow, Russian Federation.,Laboratory for Neurobiology of Memory, P.K. Anokhin Research Institute of Normal Physiology, Moscow, Russian Federation
| | - Vsevolod A Tkachuk
- Laboratory of Gene and Cell Technologies, Faculty of Medicine, Lomonosov Moscow State University, Moscow, Russian Federation.,Institute of Experimental Cardiology, Federal State Budgetary Organization National Cardiology Research Center Ministry of Health of the Russian Federation, Moscow, Russian Federation
| | - Ekaterina V Semina
- Laboratory of Gene and Cell Technologies, Faculty of Medicine, Lomonosov Moscow State University, Moscow, Russian Federation.,Institute of Experimental Cardiology, Federal State Budgetary Organization National Cardiology Research Center Ministry of Health of the Russian Federation, Moscow, Russian Federation
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Anwer M, Bolkvadze T, Puhakka N, Ndode-Ekane XE, Pitkänen A. Genotype and Injury Effect on the Expression of a Novel Hypothalamic Protein Sushi Repeat-Containing Protein X-Linked 2 (SRPX2). Neuroscience 2019; 415:184-200. [DOI: 10.1016/j.neuroscience.2019.07.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 07/04/2019] [Accepted: 07/23/2019] [Indexed: 12/17/2022]
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Kyyriäinen J, Bolkvadze T, Koivisto H, Lipponen A, Pérez LO, Ekolle Ndode-Ekane X, Tanila H, Pitkänen A. Deficiency of urokinase-type plasminogen activator and its receptor affects social behavior and increases seizure susceptibility. Epilepsy Res 2019; 151:67-74. [PMID: 30836238 DOI: 10.1016/j.eplepsyres.2019.02.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/01/2019] [Accepted: 02/23/2019] [Indexed: 12/25/2022]
Abstract
Extracellular proteolysis initiated by the binding of urokinase-type plasminogen activator (uPA) to its receptor (uPAR) regulates the development of inhibitory neuronal circuits in the cerebral cortex and tissue remodeling after epileptogenic brain injury. To study the function of different components of the uPA-uPAR system on behavior and epileptogenesis, and to complement our previous studies on naïve and injured mice deficient in the uPA-encoding gene Plau or the uPAR-encoding gene Plaur, we analyzed the behavioral phenotype, seizure susceptibility, and perineuronal nets surrounding parvalbumin-positive inhibitory interneurons in Plau and Plaur (double knockout dKO) mice. In a climbing test, dKO mice showed reduced interest towards the environment as compared with Wt mice (p < 0.01). In a social approach test, however, dKO mice spent more time than Wt mice exploring the compartment containing a stranger mouse than the empty compartment (p < 0.05). Moreover, in a social interaction test, dKO mice exhibited increased contact time (p < 0.01). Compared with Wt mice, the dKO mice also had a longer single contact duration (p < 0.001) with the stranger mouse. In the elevated plus-maze, grooming, and marble burying tests, the anxiety level of dKO mice did not differ from that of Wt mice. Rearing time in an exploratory activity test, and spatial learning and memory in the Morris swim navigation task were also comparable between dKO and Wt mice. In the pentylenetetrazol (PTZ) seizure-susceptibility test, dKO mice had a shorter latency to the first epileptiform spike (p = 0.0001) and a greater total number of spikes (p < 0.001) than Wt mice. The dKO genotype did not affect the number of cortical perineuronal nets. Our findings indicate that Plau/Plaur-deficiency leads to a more social phenotype toward other mice with diminished interest in the surrounding environment, and increased seizure susceptibility.
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Affiliation(s)
- Jenni Kyyriäinen
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Tamuna Bolkvadze
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Hennariikka Koivisto
- Neurobiology of Memory Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Anssi Lipponen
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Laura Oliva Pérez
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Xavier Ekolle Ndode-Ekane
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Heikki Tanila
- Neurobiology of Memory Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Asla Pitkänen
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland.
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Schirwani S, McConnell V, Willoughby J, Balasubramanian M. Exploring the association between SRPX2 variants and neurodevelopment: How causal is it? Gene 2018; 685:50-54. [PMID: 30393191 DOI: 10.1016/j.gene.2018.10.067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 09/15/2018] [Accepted: 10/24/2018] [Indexed: 12/23/2022]
Abstract
The SRPX2 gene (Sushi-repeat-containing protein, X-linked, 2, OMIM*300642), located on Xq22.1, encodes a secreted protein that is highly expressed in neurons of cerebral cortex. SRPX2 was first implicated in neurodevelopment, learning and rolandic seizure when two patients with potentially pathogenic variants, c.980A>G (p.Asn327Ser) and c.215A>C (p.Tyr72Ser), in SRPX2 gene were identified. Subsequent experimental studies demonstrated that SRPX2 is needed for vocalization and synapse formation in mice, and that both silencing SRPX2 and injecting (p.Asn327Ser) in mouse models results in alteration in neuronal migration in cerebral cortex and epilepsy. A number of studies demonstrated that SRPX2 interacts with FOXP2 (Foxhead box protein P2), a gene responsible for speech and language disorder, and that FoxP2 controls timing and level of expression of SRPX2. Despite the supportive evidence for the role of SRPX2 in speech and language development and disorders, there are questions over its definitive association with neurodevelopmental disorders and epilepsy. In this paper, the role of SRPX2 as one in a network of many genes involved in speech and language is discussed. The goal of this paper is to examine the role of SRPX2 variants through describing two patients with potentially pathogenic variants in SRPX2, c.751G>C (p.Ala251Pro) and c.762G>T (p.Lys254Asn) presenting with language and motor delay, intellectual disability as well as congenital anomalies. We explore the contribution of SRPX2 variants to clinical phenotype in our patients and conclude that these variants at least partially explain the phenotype. Further studies are necessary to establish and confirm the association between SRPX2 and neurodevelopment particularly speech and language development.
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Affiliation(s)
- Schaida Schirwani
- Yorkshire Regional Genetics Service, Chapel Allerton Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Vivienne McConnell
- Northern Ireland Regional Genetics Service, Belfast City Hospital, Belfast Health & Social Care Trust, Belfast, Northern Ireland BT9 7AB, UK
| | - Josh Willoughby
- Sheffield Diagnostic Genetics Service, Sheffield Children's NHS Foundation Trust, UK
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- DDD Study, Welcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Meena Balasubramanian
- Academic Unit of Child Health, Department of Oncology & Metabolism, University of Sheffield, UK; Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, UK.
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Feng Z, Tan Q, Tang J, Li L, Tao Y, Chen Y, Yang Y, Luo C, Feng H, Zhu G, Chen Q, Chen Z. Intraventricular administration of urokinase as a novel therapeutic approach for communicating hydrocephalus. Transl Res 2017; 180:77-90.e2. [PMID: 27614013 DOI: 10.1016/j.trsl.2016.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 07/18/2016] [Accepted: 08/13/2016] [Indexed: 01/10/2023]
Abstract
Fibrosis of the subarachnoid space (SAS) after infection, inflammation, or hemorrhage can impair cerebrospinal fluid absorption and circulation, causing diffuse ventricular dilatation. In the present study, we tested the hypothesis that urokinase (also known as urokinase-type plasminogen activator [uPA]), a fibrinolytic agent, attenuates fibrosis and ventriculomegaly in a rat model of kaolin-induced communicating hydrocephalus and thus may have potential as a therapy for these conditions. Thirty microliters of sterile 25% kaolin suspension was injected into the basal cisterns of adult Sprague-Dawley rats to induce hydrocephalus, and 2 intraventricular injections of either uPA or vehicle (saline) were administered immediately and 3 days thereafter. Ventricular volumes were measured by magnetic resonance imaging (MRI) on days 3, 14, and 28 after kaolin injection. Fibrosis and reactive astrogliosis were evaluated on day 28 by immunofluorescence and Western blotting. Neurocognitive features were tested using the Morris water maze from days 23 to 28. MRI analysis demonstrated that kaolin administration successfully induced hydrocephalus in rats and that uPA treatment significantly attenuated ventricular enlargement. In addition, uPA inhibited the deposition of laminin and fibronectin, extracellular matrix molecules, in the SAS, attenuated gliosis, and improved learning and memory in kaolin-treated rats. Therefore, we concluded that uPA prevents the development of kaolin-induced communicating hydrocephalus by preventing the development of subarachnoid fibrosis and by eliciting improvements in neurocognition. The results of this study indicate that uPA may be a novel clinical therapy for communicating hydrocephalus.
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Affiliation(s)
- Zhou Feng
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Qiang Tan
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Jun Tang
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Lin Li
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Yihao Tao
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Yujie Chen
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Yunfeng Yang
- Department of Neurosurgery, Sichuan Provincial Corps Hospital, Chinese People's Armed Police Forces, Leshan, People's Republic of China
| | - Chunxia Luo
- Department of Neurology, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Gang Zhu
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Qianwei Chen
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China.
| | - Zhi Chen
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China.
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Bolkvadze T, Puhakka N, Pitkänen A. Epileptogenesis after traumatic brain injury in Plaur-deficient mice. Epilepsy Behav 2016; 60:187-196. [PMID: 27208924 DOI: 10.1016/j.yebeh.2016.04.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 04/17/2016] [Accepted: 04/18/2016] [Indexed: 11/16/2022]
Abstract
Binding of the extracellular matrix proteinase urokinase-type plasminogen activator (uPA) to its receptor, uPAR, regulates tissue remodeling during development and after injury in different organs, including the brain. Accordingly, mutations in the Plaur gene, which encodes uPAR, have been linked to language deficits, autism, and epilepsy, both in mouse and human. Whether uPAR deficiency modulates epileptogenesis and comorbidogenesis after brain injury, however, is unknown. To address this question, we induced traumatic brain injury (TBI) by controlled cortical impact (CCI) in 10 wild-type (Wt-CCI) and 16 Plaur-deficient (uPAR-CCI) mice. Sham-operated mice served as controls (10 Wt-sham, 10 uPAR-sham). During the 4-month follow-up, the mice were neurophenotyped by assessing the somatomotor performance with the composite neuroscore test, emotional learning and memory with fear conditioning to tone and context, and epileptogenesis with videoelectroencephalography monitoring and the pentylenetetrazol (PTZ) seizure susceptibility test. At the end of the testing, the mice were perfused for histology to analyze cortical and hippocampal neurodegeneration and mossy fiber sprouting. Fourteen percent (1/7) of the mice in the Wt-CCI and 0% in the uPAR-CCI groups developed spontaneous seizures (p>0.05; chi-square). Both the Wt-CCI and uPAR-CCI groups showed increased seizure susceptibility in the PTZ test (p<0.05), impaired recovery of motor function (p<0.001), and neurodegeneration in the hippocampus and cortex (p<0.05) compared with the corresponding sham-operated controls. Motor recovery and emotional learning showed a genotype effect, being more impaired in uPAR-CCI than in Wt-CCI mice (p<0.05). The findings of the present study indicate that uPAR deficiency does not increase susceptibility to epileptogenesis after CCI injury but has an unfavorable comorbidity-modifying effect after TBI.
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Affiliation(s)
- Tamuna Bolkvadze
- Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Noora Puhakka
- Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Asla Pitkänen
- Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland.
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Jiang X, Lachance M, Rossignol E. Involvement of cortical fast-spiking parvalbumin-positive basket cells in epilepsy. PROGRESS IN BRAIN RESEARCH 2016; 226:81-126. [PMID: 27323940 DOI: 10.1016/bs.pbr.2016.04.012] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
GABAergic interneurons of the parvalbumin-positive fast-spiking basket cells subtype (PV INs) are important regulators of cortical network excitability and of gamma oscillations, involved in signal processing and cognition. Impaired development or function of PV INs has been associated with epilepsy in various animal models of epilepsy, as well as in some genetic forms of epilepsy in humans. In this review, we provide an overview of some of the experimental data linking PV INs dysfunction with epilepsy, focusing on disorders of the specification, migration, maturation, synaptic function, or connectivity of PV INs. Furthermore, we reflect on the potential therapeutic use of cell-type specific stimulation of PV INs within active networks and on the transplantation of PV INs precursors in the treatment of epilepsy and its comorbidities.
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Affiliation(s)
- X Jiang
- Université de Montréal, Montréal, QC, Canada; CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - M Lachance
- CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - E Rossignol
- Université de Montréal, Montréal, QC, Canada; CHU Ste-Justine Research Center, Montréal, QC, Canada.
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Semina E, Rubina K, Sysoeva V, Rysenkova K, Klimovich P, Plekhanova O, Tkachuk V. Urokinase and urokinase receptor participate in regulation of neuronal migration, axon growth and branching. Eur J Cell Biol 2016; 95:295-310. [PMID: 27324124 DOI: 10.1016/j.ejcb.2016.05.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 05/27/2016] [Accepted: 05/31/2016] [Indexed: 10/21/2022] Open
Abstract
PURPOSE Recent findings indicate the significant contribution of urokinase and urokinase receptor (uPA and uPAR) in the processes of nerve regeneration, however, their role in axonal growth and branching is unclear. Using a 3D model of mouse Dorsal Root Ganglia (DRG) explants, differentiated into neurons Neuro 2a cells and transgenic mice lacking the urokinase gene, we studied the involvement of the uPA/uPAR system in the neural cell migration, neurite outgrowth, elongation and branching. RESULTS uPA and uPAR are expressed in the growth cones of axons. Using an ex vivo model of DRG explants in Matrigel we have found that uPA inhibition attenuates neural cell migration and axonal growth, pointing to an important role of urokinase in these processes. Apparently, uPA mediates its effects through its specific receptor uPAR: anti-uPAR antibody, which blocks the uPA binding to uPAR, stimulates axon branching and attenuates neural cell migration from DRG explants. Simultaneous inhibition of uPA and uPAR almost completely prevents the axonal outgrowth from explants into the Matrigels. Experiments in vitro using Neuro 2a cells differentiated into neurons demonstrate that administration of exogenous uPA increases the neurite growth rate (elongation), most likely via the interaction of uPA with uPAR. Blocking of uPAR stimulates neurite formation and enhances branching of preexisting neurites. The results obtained on DRG explants from transgenic mice lacking uPA gene support the assumption that uPA stimulates neurite growth via uPA/uPAR interaction and uPAR role in axons branching and neural cell migration. CONCLUSIONS The uPA/uPAR system plays an essential role in neural cell migration, axonal growth and branching.
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Affiliation(s)
- Ekaterina Semina
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, M.V. Lomonosov Moscow State University, Lomonosovsky av. 31/5, 119192 Moscow, Russian Federation; Laboratory of Molecular Endocrinology, Russian Cardiology Research Center, 3rd Cherepkovskaya 15a, 12155 Moscow, Russian Federation
| | - Kseniya Rubina
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, M.V. Lomonosov Moscow State University, Lomonosovsky av. 31/5, 119192 Moscow, Russian Federation.
| | - Veronika Sysoeva
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, M.V. Lomonosov Moscow State University, Lomonosovsky av. 31/5, 119192 Moscow, Russian Federation
| | - Karina Rysenkova
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, M.V. Lomonosov Moscow State University, Lomonosovsky av. 31/5, 119192 Moscow, Russian Federation
| | - Polina Klimovich
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, M.V. Lomonosov Moscow State University, Lomonosovsky av. 31/5, 119192 Moscow, Russian Federation
| | - Olga Plekhanova
- Laboratory of Molecular Endocrinology, Russian Cardiology Research Center, 3rd Cherepkovskaya 15a, 12155 Moscow, Russian Federation
| | - Vsevolod Tkachuk
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, M.V. Lomonosov Moscow State University, Lomonosovsky av. 31/5, 119192 Moscow, Russian Federation; Laboratory of Molecular Endocrinology, Russian Cardiology Research Center, 3rd Cherepkovskaya 15a, 12155 Moscow, Russian Federation
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Schmalbach B, Lepsveridze E, Djogo N, Papashvili G, Kuang F, Leshchyns'ka I, Sytnyk V, Nikonenko AG, Dityatev A, Jakovcevski I, Schachner M. Age-dependent loss of parvalbumin-expressing hippocampal interneurons in mice deficient in CHL1, a mental retardation and schizophrenia susceptibility gene. J Neurochem 2015; 135:830-44. [PMID: 26285062 DOI: 10.1111/jnc.13284] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 08/05/2015] [Accepted: 08/07/2015] [Indexed: 02/05/2023]
Abstract
In humans, deletions/mutations in the CHL1/CALL gene are associated with mental retardation and schizophrenia. Juvenile CHL1-deficient (CHL1(-/-) ) mice have been shown to display abnormally high numbers of parvalbumin-expressing (PV(+) ) hippocampal interneurons and, as adults, display behavioral traits observed in neuropsychiatric disorders. Here, we addressed the question whether inhibitory interneurons and synaptic plasticity in the CHL1(-/-) mouse are affected during brain maturation and in adulthood. We found that hippocampal, but not neocortical, PV(+) interneurons were reduced with age in CHL1(-/-) mice, from a surplus of +27% at 1 month to a deficit of -20% in adulthood compared with wild-type littermates. This loss occurred during brain maturation, correlating with microgliosis and enhanced interleukin-6 expression. In parallel with the loss of PV(+) interneurons, the inhibitory input to adult CA1 pyramidal cells was reduced and a deficit in short- and long-term potentiation developed at CA3-CA1 excitatory synapses between 2 and 9 months of age in CHL1(-/-) mice. This deficit could be abrogated by a GABAA receptor agonist. We propose that region-specific aberrant GABAergic synaptic connectivity resulting from the mutation and a subsequently enhanced synaptic elimination during brain maturation lead to microgliosis, increase in pro-inflammatory cytokine levels, loss of interneurons, and impaired synaptic plasticity. Close homolog of L1-deficient (CHL1(-/-) ) mice have abnormally high numbers of parvalbumin (PV)-expressing hippocampal interneurons in juvenile animals, but in adult animals a loss of these cells is observed. This loss correlates with an increased density of microglia (M), enhanced interleukin-6 (IL6) production and a deficit in short- and long-term potentiation at CA3-CA1 excitatory synapses. Furthermore, adult CHL1(-/-) mice display behavioral traits similar to those observed in neuropsychiatric disorders of humans.
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Affiliation(s)
- Barbara Schmalbach
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
| | - Eka Lepsveridze
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
- Ilia State University, Tbilisi, Georgia
| | - Nevena Djogo
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
| | - Giorgi Papashvili
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
| | - Fang Kuang
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
| | - Iryna Leshchyns'ka
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Vladimir Sytnyk
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Alexander G Nikonenko
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
- Department of Cytology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - Alexander Dityatev
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen, Magdeburg, Germany
| | - Igor Jakovcevski
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
- Experimental Neurophysiology, University Hospital Cologne, Köln, Germany
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Melitta Schachner
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
- Department of Cell Biology and Neuroscience, Keck Center for Collaborative Neuroscience, Rutgers University, Piscataway, New Jersey, USA
- Center for Neuroscience, Shantou University Medical College, Shantou, China
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Leclercq K, Afrikanova T, Langlois M, De Prins A, Buenafe OE, Rospo CC, Van Eeckhaut A, de Witte PAM, Crawford AD, Smolders I, Esguerra CV, Kaminski RM. Cross-species pharmacological characterization of the allylglycine seizure model in mice and larval zebrafish. Epilepsy Behav 2015; 45:53-63. [PMID: 25845493 DOI: 10.1016/j.yebeh.2015.03.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 03/16/2015] [Accepted: 03/17/2015] [Indexed: 01/29/2023]
Abstract
Treatment-resistant seizures affect about a third of patients suffering from epilepsy. To fulfill the need for new medications targeting treatment-resistant seizures, a number of rodent models offer the opportunity to assess a variety of potential treatment approaches. The use of such models, however, has proven to be time-consuming and labor-intensive. In this study, we performed pharmacological characterization of the allylglycine (AG) seizure model, a simple in vivo model for which we demonstrated a high level of treatment resistance. (d,l)-Allylglycine inhibits glutamic acid decarboxylase (GAD) - the key enzyme in γ-aminobutyric acid (GABA) biosynthesis - leading to GABA depletion, seizures, and neuronal damage. We performed a side-by-side comparison of mouse and zebrafish acute AG treatments including biochemical, electrographic, and behavioral assessments. Interestingly, seizure progression rate and GABA depletion kinetics were comparable in both species. Five mechanistically diverse antiepileptic drugs (AEDs) were used. Three out of the five AEDs (levetiracetam, phenytoin, and topiramate) showed only a limited protective effect (mainly mortality delay) at doses close to the TD50 (dose inducing motor impairment in 50% of animals) in mice. The two remaining AEDs (diazepam and sodium valproate) displayed protective activity against AG-induced seizures. Experiments performed in zebrafish larvae revealed behavioral AED activity profiles highly analogous to those obtained in mice. Having demonstrated cross-species similarities and limited efficacy of tested AEDs, we propose the use of AG in zebrafish as a convenient and high-throughput model of treatment-resistant seizures.
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Affiliation(s)
| | - Tatiana Afrikanova
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium
| | - Melanie Langlois
- Luxembourg Center for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - An De Prins
- Center for Neurosciences, C4N, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Olivia E Buenafe
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium
| | - Chiara C Rospo
- Neuroscience TA, UCB Biopharma, Braine-l'Alleud, Belgium
| | - Ann Van Eeckhaut
- Luxembourg Center for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Peter A M de Witte
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium
| | - Alexander D Crawford
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium; Luxembourg Center for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Ilse Smolders
- Center for Neurosciences, C4N, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Camila V Esguerra
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium; Chemical Neuroscience Group, Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway.
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Interneurons are necessary for coordinated activity during reversal learning in orbitofrontal cortex. Biol Psychiatry 2015; 77:454-64. [PMID: 25193243 PMCID: PMC4312743 DOI: 10.1016/j.biopsych.2014.07.023] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 07/22/2014] [Accepted: 07/23/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND Cerebral cortical gamma-aminobutyric acidergic interneuron dysfunction is hypothesized to lead to cognitive deficits comorbid with human neuropsychiatric disorders, including schizophrenia, autism, and epilepsy. We have previously shown that mice that harbor mutations in the Plaur gene, which is associated with schizophrenia, have deficits in frontal cortical parvalbumin-expressing interneurons. Plaur mice have impaired reversal learning, similar to deficits observed in patients with schizophrenia. METHODS We examined the role of parvalbumin interneurons in orbitofrontal cortex during reversal learning by recording single unit activity from 180 control and 224 Plaur mouse neurons during a serial reversal task. Neural activity was analyzed during correct and incorrect decision choices and reward receipt. RESULTS Neurons in control mice exhibited strong phasic responses both during discrimination and reversal learning to decisions and rewards, and the strength of the response was correlated with behavioral performance. Although baseline firing was significantly enhanced in Plaur mice, neural selectivity for correct or erroneous decisions was diminished and not correlated with behavior, and reward encoding was downscaled. In addition, Plaur mice showed a significant reduction in the number of neurons that encoded expected outcomes across task phases during the decision period. CONCLUSIONS These data indicate that parvalbumin interneurons are necessary for the representation of outcomes in orbitofrontal cortex. Deficits in inhibition blunt selective neural firing during key decisions, contributing to behavioral inflexibility. These data provide a potential explanation for disorders of cognitive control that accompany the loss of these gamma-aminobutyric acidergic interneurons in human neuropsychiatric disorders, such as autism, epilepsy, and schizophrenia.
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Rantala J, Kemppainen S, Ndode-Ekane XE, Lahtinen L, Bolkvadze T, Gurevicius K, Tanila H, Pitkänen A. Urokinase-type plasminogen activator deficiency has little effect on seizure susceptibility and acquired epilepsy phenotype but reduces spontaneous exploration in mice. Epilepsy Behav 2015; 42:117-28. [PMID: 25506794 DOI: 10.1016/j.yebeh.2014.11.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/03/2014] [Accepted: 11/08/2014] [Indexed: 01/05/2023]
Abstract
Urokinase-type plasminogen activator (uPA), a serine protease, converts plasminogen to plasmin. Activation of plasmin leads to degradation of the extracellular matrix, which is critical for tissue recovery, angiogenesis, cell migration, and axonal and synaptic plasticity. We hypothesized that uPA deficiency would cause an abnormal neurophenotype and would lead to exacerbated epileptogenesis after brain injury. Wild-type (Wt) and uPA-/- mice underwent a battery of neurologic behavioral tests evaluating general reactivity, spontaneous exploratory activity, motor coordination, pain threshold, fear and anxiety, and memory. We placed particular emphasis on the effect of uPA deficiency on seizure susceptibility, including the response to convulsants (pentylenetetrazol, kainate, or pilocarpine) and kainate-induced epileptogenesis and epilepsy. The uPA-/- mice showed no motor or sensory impairment compared with the Wt mice. Hippocampus-dependent spatial memory also remained intact. The uPA-/- mice, however, exhibited reduced exploratory activity and an enhanced response to a tone stimulus (p<0.05 compared with the Wt mice). The urokinase-type plasminogen activator deficient mice showed no increase in spontaneous or evoked epileptiform electrographic activity. Rather, the response to pilocarpine administration was reduced compared with the Wt mice (p<0.05). Also, the epileptogenesis and the epilepsy phenotype after intrahippocampal kainate injection were similar to those in the Wt mice. Taken together, uPA deficiency led to diminished interest in the environmental surroundings and enhanced emotional reactivity to unexpected aversive stimuli. Urokinase-type plasminogen activator deficiency was not associated with enhanced seizure susceptibility or worsened poststatus epilepticus epilepsy phenotype.
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Affiliation(s)
- J Rantala
- Epilepsy Research Laboratory, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - S Kemppainen
- Neurobiology of Memory Laboratory, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - X E Ndode-Ekane
- Epilepsy Research Laboratory, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - L Lahtinen
- Epilepsy Research Laboratory, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - Tamuna Bolkvadze
- Epilepsy Research Laboratory, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - K Gurevicius
- Neurobiology of Memory Laboratory, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - H Tanila
- Neurobiology of Memory Laboratory, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland; Department of Neurology, Kuopio University Hospital, PO Box 1777, FIN-70211 Kuopio, Finland
| | - A Pitkänen
- Epilepsy Research Laboratory, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland; Department of Neurology, Kuopio University Hospital, PO Box 1777, FIN-70211 Kuopio, Finland.
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16
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Carayol J, Schellenberg GD, Dombroski B, Amiet C, Génin B, Fontaine K, Rousseau F, Vazart C, Cohen D, Frazier TW, Hardan AY, Dawson G, Rio Frio T. A scoring strategy combining statistics and functional genomics supports a possible role for common polygenic variation in autism. Front Genet 2014; 5:33. [PMID: 24600472 PMCID: PMC3927086 DOI: 10.3389/fgene.2014.00033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 01/29/2014] [Indexed: 12/23/2022] Open
Abstract
Autism spectrum disorders (ASD) are highly heritable complex neurodevelopmental disorders with a 4:1 male: female ratio. Common genetic variation could explain 40-60% of the variance in liability to autism. Because of their small effect, genome-wide association studies (GWASs) have only identified a small number of individual single-nucleotide polymorphisms (SNPs). To increase the power of GWASs in complex disorders, methods like convergent functional genomics (CFG) have emerged to extract true association signals from noise and to identify and prioritize genes from SNPs using a scoring strategy combining statistics and functional genomics. We adapted and applied this approach to analyze data from a GWAS performed on families with multiple children affected with autism from Autism Speaks Autism Genetic Resource Exchange (AGRE). We identified a set of 133 candidate markers that were localized in or close to genes with functional relevance in ASD from a discovery population (545 multiplex families); a gender specific genetic score (GS) based on these common variants explained 1% (P = 0.01 in males) and 5% (P = 8.7 × 10(-7) in females) of genetic variance in an independent sample of multiplex families. Overall, our work demonstrates that prioritization of GWAS data based on functional genomics identified common variants associated with autism and provided additional support for a common polygenic background in autism.
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Affiliation(s)
| | - Gerard D. Schellenberg
- Department of Pathology and Laboratory Medicine, University of PennsylvaniaPhiladelphia, PA, USA
| | - Beth Dombroski
- Department of Pathology and Laboratory Medicine, University of PennsylvaniaPhiladelphia, PA, USA
| | | | | | | | | | | | - David Cohen
- Groupe Hospitalier Pitié-Salpêtrière, Department of Child and Adolescent Psychiatry, AP-HP, Université Pierre et Marie CurieParis, France
| | - Thomas W. Frazier
- Center for Pediatric Behavioral Health and Center for Autism, Cleveland ClinicCleveland, OH, USA
| | - Antonio Y. Hardan
- Department of Psychiatry and Behavioral Sciences, Stanford UniversityStanford, CA, USA
| | - Geraldine Dawson
- Department of Psychiatry and Behavioral Sciences, Duke University Medical CenterDurham, NC, USA
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Condro MC, White SA. Recent Advances in the Genetics of Vocal Learning. COMPARATIVE COGNITION & BEHAVIOR REVIEWS 2014; 9:75-98. [PMID: 26052371 DOI: 10.3819/ccbr.2014.90003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Language is a complex communicative behavior unique to humans, and its genetic basis is poorly understood. Genes associated with human speech and language disorders provide some insights, originating with the FOXP2 transcription factor, a mutation in which is the source of an inherited form of developmental verbal dyspraxia. Subsequently, targets of FOXP2 regulation have been associated with speech and language disorders, along with other genes. Here, we review these recent findings that implicate genetic factors in human speech. Due to the exclusivity of language to humans, no single animal model is sufficient to study the complete behavioral effects of these genes. Fortunately, some animals possess subcomponents of language. One such subcomponent is vocal learning, which though rare in the animal kingdom, is shared with songbirds. We therefore discuss how songbird studies have contributed to the current understanding of genetic factors that impact human speech, and support the continued use of this animal model for such studies in the future.
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Affiliation(s)
- Michael C Condro
- Molecular, Cellular and Integrative Physiology Interdepartmental Program, University of California, Los Angeles
| | - Stephanie A White
- Department of Integrative Biology and Physiology, University of California, Los Angeles
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18
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Jovanov Milošević N, Judaš M, Aronica E, Kostovic I. Neural ECM in laminar organization and connectivity development in healthy and diseased human brain. PROGRESS IN BRAIN RESEARCH 2014; 214:159-78. [DOI: 10.1016/b978-0-444-63486-3.00007-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Bissonette GB, Bae MH, Suresh T, Jaffe DE, Powell EM. Prefrontal cognitive deficits in mice with altered cerebral cortical GABAergic interneurons. Behav Brain Res 2013; 259:143-51. [PMID: 24211452 DOI: 10.1016/j.bbr.2013.10.051] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 10/25/2013] [Accepted: 10/30/2013] [Indexed: 12/26/2022]
Abstract
Alterations of inhibitory GABAergic neurons are implicated in multiple psychiatric and neurological disorders, including schizophrenia, autism and epilepsy. In particular, interneuron deficits in prefrontal areas, along with presumed decreased inhibition, have been reported in several human patients. The majority of forebrain GABAergic interneurons arise from a single subcortical source before migrating to their final regional destination. Factors that govern the interneuron populations have been identified, demonstrating that a single gene mutation may globally affect forebrain structures or a single area. In particular, mice lacking the urokinase plasminogen activator receptor (Plaur) gene have decreased GABAergic interneurons in frontal and parietal, but not caudal, cortical regions. Plaur assists in the activation of hepatocyte growth factor/scatter factor (HGF/SF), and several of the interneuron deficits are correlated with decreased levels of HGF/SF. In some cortical regions, the interneuron deficit can be remediated by endogenous overexpression of HGF/SF. In this study, we demonstrate decreased parvalbumin-expressing interneurons in the medial frontal cortex, but not in the hippocampus or basal lateral amygdala in the Plaur null mouse. The Plaur null mouse demonstrates impaired medial frontal cortical function in extinction of cued fear conditioning and the inability to form attentional sets. Endogenous HGF/SF overexpression increased the number of PV-expressing cells in medial frontal cortical areas to levels greater than found in wildtype mice, but did not remediate the behavioral deficits. These data suggest that proper medial frontal cortical function is dependent upon optimum levels of inhibition and that a deficit or excess of interneuron numbers impairs normal cognition.
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Affiliation(s)
- Gregory B Bissonette
- Program in Neuroscience, University of Maryland, Baltimore, Baltimore, MD 21201, USA
| | - Mihyun H Bae
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Tejas Suresh
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - David E Jaffe
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Elizabeth M Powell
- Program in Neuroscience, University of Maryland, Baltimore, Baltimore, MD 21201, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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20
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Peng Y, Huentelman M, Smith C, Qiu S. MET receptor tyrosine kinase as an autism genetic risk factor. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2013; 113:135-65. [PMID: 24290385 DOI: 10.1016/b978-0-12-418700-9.00005-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In this chapter, we will briefly discuss recent literature on the role of MET receptor tyrosine kinase (RTK) in brain development and how perturbation of MET signaling may alter normal neurodevelopmental outcomes. Recent human genetic studies have established MET as a risk factor for autism, and the molecular and cellular underpinnings of this genetic risk are only beginning to emerge from obscurity. Unlike many autism risk genes that encode synaptic proteins, the spatial and temporal expression pattern of MET RTK indicates this signaling system is ideally situated to regulate neuronal growth, functional maturation, and establishment of functional brain circuits, particularly in those brain structures involved in higher levels of cognition, social skills, and executive functions.
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Affiliation(s)
- Yun Peng
- Department of Basic Medical Sciences, University of Arizona College of Medicine, Phoenix, Arizona, USA
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21
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Ndode-Ekane XE, Pitkänen A. Urokinase-type plasminogen activator receptor modulates epileptogenesis in mouse model of temporal lobe epilepsy. Mol Neurobiol 2012; 47:914-37. [PMID: 23263886 DOI: 10.1007/s12035-012-8386-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 12/04/2012] [Indexed: 11/24/2022]
Abstract
Mutation in Plaur gene encoding urokinase-type plasminogen activator receptor (uPAR) results in epilepsy and autistic phenotype in mice. In humans, a single nucleotide polymorphism in PLAUR gene represents a risk for autism spectrum disorders. Importantly, the expression of uPAR is elevated in the brain after various epileptogenic insults like traumatic brain injury and status epilepticus. So far, the consequences of altered uPAR expression on brain networks are poorly known. We tested a hypothesis that uPAR regulates post-injury neuronal reorganization and consequent functional outcome, particularly epileptogenesis. Epileptogenesis was induced by intrahippocampal injection of kainate in adult male wild type (Wt) or uPAR knockout (uPAR-/-) mice, and animals were monitored with continuous (24/7) video-electroencephalogram for 30 days. The severity of status epilepticus did not differ between the genotypes. The spontaneous electrographic seizures which developed were, however, longer and their behavioral manifestations were more severe in uPAR-/- than Wt mice. The more severe epilepsy phenotype in uPAR-/- mice was associated with delayed but augmented inflammatory response and more severe neurodegeneration in the hippocampus. Also, the distribution of newly born cells in the dentate gyrus was more scattered, and the recovery of hippocampal blood vessel length from status epilepticus-induced damage was compromised in uPAR-/- mice as compared to Wt mice. Our data demonstrate that a deficiency in uPAR represents a mechanisms which results in the development of a more severe epilepsy phenotype and progressive brain pathology after status epilepticus. We suggest that uPAR represents a rational target for disease-modifying treatments after epileptogenic brain insults.
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Affiliation(s)
- Xavier Ekolle Ndode-Ekane
- Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, P. O. Box 1627, 70 211 Kuopio, Finland.
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22
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Hammock EA, Levitt P. Modulation of parvalbumin interneuron number by developmentally transient neocortical vasopressin receptor 1a (V1aR). Neuroscience 2012; 222:20-8. [PMID: 22820266 PMCID: PMC3444161 DOI: 10.1016/j.neuroscience.2012.07.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 07/09/2012] [Accepted: 07/11/2012] [Indexed: 11/30/2022]
Abstract
Arginine-vasopressin (AVP) and the vasopressin 1a receptor (V1aR) modulate social behavior and learning and memory in adult animals. Both functions depend upon the normal emergence of the balance of excitation and inhibition (E/I balance) in the neocortex. Here, we tested the hypothesis that V1aR signaling and E/I balance converge through the influence of the neuropeptide on interneuron number achieved in the neocortex. Postnatal mapping of forebrain V1aR binding in male and female mice revealed a transient expression of high levels of receptor in the neocortex and hippocampus in the second and third post-natal weeks. Receptor binding levels in these cortical structures fell dramatically in the adult, maintaining high levels of expression subcortically. Surprisingly, we observed sex differences in the number of calbindin interneurons, and a contribution of V1aR to the number of parvalbumin-immunoreactive neurons in the adult mouse neocortex. These data suggest that individual differences in developmentally transient V1aR signaling and even sex may alter the development of E/I balance in the neocortex, with long-lasting influence on information processing.
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Affiliation(s)
- Elizabeth A.D. Hammock
- Department of Pediatrics, Vanderbilt University School of Medicine & Vanderbilt Kennedy Center, Vanderbilt University, Nashville TN, 37232
| | - Pat Levitt
- Zilkha Neurogenetic Institute, Department of Cell and Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
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23
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Qiu S, Aldinger KA, Levitt P. Modeling of autism genetic variations in mice: focusing on synaptic and microcircuit dysfunctions. Dev Neurosci 2012; 34:88-100. [PMID: 22572629 DOI: 10.1159/000336644] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 12/21/2011] [Indexed: 12/24/2022] Open
Abstract
Autism spectrum disorders (ASD) are heterogeneous neurodevelopmental disorders that are characterized by deficits in social interaction, verbal and nonverbal communication, and restrictive interests and repetitive behaviors. While human genetic studies have revealed marked heritability in ASD, it has been challenging to translate this genetic risk into a biological mechanism that influences brain development relevant to the disorder phenotypes. This is partly due to the complex genetic architecture of ASD, which involves de novo gene mutations, genomic abnormalities, and common genetic variants. Rather than trying to reconstitute the clinical disorder, using genetic model animals to examine specific features of core ASD pathophysiology offers unique opportunities for refining our understanding of neurodevelopmental mechanisms in ASD. A variety of ASD-relevant phenotypes can now be investigated in rodents, including stereotyped and repetitive behaviors, and deficits in social interaction and communication. In this review, we focus on several prevailing mouse models and discuss how studies have advanced our understanding of synaptic mechanisms that may underlie ASD pathophysiology. Although synaptic perturbations are not the only alterations relevant for ASD, we reason that understanding the synaptic underpinnings of ASD using mouse models may provide mechanistic insights into its etiology and lead to novel therapeutic and interventional strategies.
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Affiliation(s)
- Shenfeng Qiu
- Department of Cell and Neurobiology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, Calif., USA
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24
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Liu B, Zhang B, Wang T, Liang QC, Jing XR, Zheng J, Wang C, Meng Q, Wang L, Wang W, Guo H, You Y, Zhang H, Gao GD. Increased expression of urokinase-type plasminogen activator receptor in the frontal cortex of patients with intractable frontal lobe epilepsy. J Neurosci Res 2011; 88:2747-54. [PMID: 20648659 DOI: 10.1002/jnr.22419] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Urokinase-type plasminogen activator receptor (uPAR) is a glycosyl phosphatidylinositol-anchored protein involved in cell adhesion, proliferation, differentiation, migration, invasion, and tissue repair and remodeling. Our aim was to investigate uPAR expression in the frontal cortex of patients with intractable frontal lobe epilepsy and to explore the possible role of uPAR in intractable epilepsy. Tissue samples were obtained from the frontal cortex of 25 patients who had undergone surgery for intractable epilepsy and 15 histologically normal frontal cortex tissues from patients with orbital frontal lobe severe contusion (the control group). The frontal cortex expression of uPAR was studied by Western blot and immnohistochemistry. Double immunofluorescence was used to determine the expression of uPAR in astrocytes, microglia, and neurons. The normal frontal cortex uPAR protein level was shown to be low. In the brain tissue of patients with intractable epilepsy, the expression of uPAR protein increased dramatically. Based on the results of double immunofluorescence, many uPAR-positive cells are colocalized with the cell soma of NeuN-positive neurons, whereas only a few GFAP- and CD11b-positive cells colocalized with uPAR staining. These findings provide new information pertaining to the epileptogenesis of intractable epilepsy and suggest that increased expression of uPAR in human brain may be associated with human intractable epilepsy.
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Affiliation(s)
- Bei Liu
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, People's Republic of China
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Eagleson KL, Campbell DB, Thompson BL, Bergman MY, Levitt P. The autism risk genes MET and PLAUR differentially impact cortical development. Autism Res 2010; 4:68-83. [PMID: 21328570 DOI: 10.1002/aur.172] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 11/01/2010] [Indexed: 02/06/2023]
Abstract
Candidate risk genes for autism spectrum disorder (ASD) have been identified, but the challenge of determining their contribution to pathogenesis remains. We previously identified two ASD risk genes encoding the receptor tyrosine kinase MET and the urokinase plasminogen activator receptor (PLAUR), which is thought to modulate availability of the MET ligand. We also reported a role for Met signaling in cortical interneuron development in vitro and a reduction of these neurons in uPAR (mouse ortholog of PLAUR) null mice, suggesting that disruption of either gene impacts cortical development similarly. Here, we modify this conclusion, reporting that interneuron numbers are unchanged in the neocortex of Met(fx/fx) / Dlx5/6(cre) mice, in which Met is ablated from cells arising from the ventral telencephalon (VTel). Consistent with this, Met transcript is not detected in the VTel during interneuron genesis and migration; furthermore, during the postnatal period of interneuron maturation, Met is co-expressed in glutamatergic projection neurons, but not interneurons. Low levels of Met protein are expressed in the VTel at E12.5 and E14.5, likely reflecting the arrival of Met containing corticofugal axons. Met expression, however, is induced in E12.5 VTel cells after 2 days in vitro, perhaps underlying discrepancies between observations in vitro and in Met(fx/fx) / Dlx5/6(cre) mice. We suggest that, in vivo, Met impacts the development of cortical projection neurons, whereas uPAR influences interneuron maturation. An altered balance between excitation and inhibition has been postulated as a biological mechanism for ASD; this imbalance could arise from different risk genes differentially affecting either or both elements.
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Affiliation(s)
- Kathie L Eagleson
- Zilkha Neurogenetic Institute, Keck School of Medicine at USC, Los Angeles, California 90033, USA.
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Modulation of neurotransmitter receptors and synaptic differentiation by proteins containing complement-related domains. Neurosci Res 2010; 69:87-92. [PMID: 21093502 DOI: 10.1016/j.neures.2010.11.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 10/25/2010] [Accepted: 11/09/2010] [Indexed: 11/20/2022]
Abstract
Neurotransmitter receptors play central roles in basic neurotransmission and synaptic plasticity. Recent studies have revealed that some transmembrane and extracellular proteins bind to neurotransmitter receptors, forming protein complexes that are required for proper synaptic localization or gating of core receptor molecules. Consequently, the components of these complexes contribute to long-term potentiation, a process that is critical for learning and memory. Here, we review factors that regulate neurotransmitter receptors, with a focus on proteins containing CUB (complement C1r/C1s, Uegf, Bmp1) or CCP (complement control protein) domains, which are frequently found in complement system proteins. Proteins that contain these domains are structurally distinct from TARPs (transmembrane AMPA receptor regulatory proteins), and may constitute new protein families that modulate either the localization or function of neurotransmitter receptors. In addition, other CCP domain-containing proteins participate in dendritic patterning and/or synaptic differentiation, although current evidence has not identified any direct activities on neurotransmitter receptors. Some of these proteins are involved in pathologic conditions such as epileptic seizure and mental retardation. Together, these lines of information have shown that CUB and CCP domain-containing proteins contribute to a wide variety of neuronal events that ultimately establish neural circuits.
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Astrocyte-mediated hepatocyte growth factor/scatter factor supplementation restores GABAergic interneurons and corrects reversal learning deficits in mice. J Neurosci 2010; 30:2918-23. [PMID: 20181589 DOI: 10.1523/jneurosci.5268-09.2010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Many psychiatric and neurological disorders present persistent neuroanatomical abnormalities in multiple brain regions that may reflect a common origin for a developmental disturbance. In mammals, many of the local GABAergic inhibitory interneurons arise from a single subcortical source. Perturbations in the ontogeny of the GABAergic interneurons may be reflected in the adult by interneuron deficits in both frontal cerebral cortical and striatal regions. Disrupted GABAergic circuitry has been reported in patients with schizophrenia and frontal lobe epilepsy and may contribute to their associated impairments in behavioral flexibility. The present study demonstrates that one type of behavioral flexibility, reversal learning, is dependent upon proper numbers of GABAergic interneurons. Mice with abnormal interneuron ontogeny have reduced numbers of parvalbumin-expressing GABAergic local interneurons in the orbitofrontal cortical and striatal regions and impaired reversal leaning. Using a genetic approach, both the anatomical and functional deficiencies are restored with exogenous postnatal growth factor supplementation. These results show that GABAergic local circuitry is critical for modulating behavioral flexibility and that birth defects can be corrected by replenishing crucial growth factors.
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Eagleson KL, Gravielle MC, Schlueter McFadyen-Ketchum LJ, Russek SJ, Farb DH, Levitt P. Genetic disruption of the autism spectrum disorder risk gene PLAUR induces GABAA receptor subunit changes. Neuroscience 2010; 168:797-810. [PMID: 20381588 DOI: 10.1016/j.neuroscience.2010.03.066] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 03/23/2010] [Accepted: 03/31/2010] [Indexed: 11/27/2022]
Abstract
Disruption of the GABAergic system has been implicated in multiple developmental disorders, including epilepsy, autism spectrum disorder and schizophrenia. The human gene encoding uPAR (PLAUR) has been shown recently to be associated with the risk of autism. The uPAR(-/-) mouse exhibits a regionally-selective reduction in GABAergic interneurons in frontal and parietal regions of the cerebral cortex as well as in the CA1 and dentate gyrus subfields of the hippocampus. Behaviorally, these mice exhibit increased sensitivity to pharmacologically-induced seizures, heightened anxiety, and atypical social behavior. Here, we explore potential alterations in GABAergic circuitry that may occur in the context of altered interneuron development. Analysis of gene expression for 13 GABA(A) receptor subunits using quantitative real-time polymerase chain reaction (PCR) indicates seven subunit mRNAs (alpha(1), alpha(2), alpha(3), beta(2), beta(3), gamma(2S) and gamma(2L)) of interest. Semi-quantitative in situ hybridization analysis focusing on these subunit mRNAs reveals a complex pattern of potential gene regulatory adaptations. The levels of alpha(2) subunit mRNAs increase in frontal cortex, CA1 and CA3, while those of alpha3 decrease in frontal cortex and CA1. In contrast, alpha(1) subunit mRNAs are unaltered in any region examined. beta(2) subunit mRNAs are increased in frontal cortex whereas beta(3) subunit mRNAs are decreased in parietal cortex. Finally, gamma(2S) subunit mRNAs are increased in parietal cortex while gamma(2L) subunit mRNAs are increased in the dentate gyrus, potentially altering the gamma(2S):gamma(2L) ratio in these two regions. For all subunits, no changes were observed in forebrain regions where GABAergic interneuron numbers are normal. We propose that disrupted differentiation of GABAergic neurons specifically in frontal and parietal cortices leads to regionally-selective alterations in local circuitry and subsequent adaptive changes in receptor subunit composition. Future electrophysiological studies will be useful in determining how alterations in network activity in the cortex and hippocampus relate to the observed behavioral phenotype.
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Affiliation(s)
- K L Eagleson
- Zilkha Neurogenetic Institute and Department of Cell and Neurobiology, Keck School of Medicine at University of Southern California, 1501 San Pablo Street, Los Angeles, CA 90033, USA.
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Nagai N, Matsuo O. Roles of fibrinolytic system components in the nervous system. PATHOPHYSIOLOGY 2010; 17:141-7. [DOI: 10.1016/j.pathophys.2009.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 03/10/2009] [Accepted: 03/23/2009] [Indexed: 10/20/2022] Open
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Tissue plasminogen activator and urokinase plasminogen activator in human epileptogenic pathologies. Neuroscience 2010; 167:929-45. [PMID: 20219643 DOI: 10.1016/j.neuroscience.2010.02.047] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2009] [Revised: 02/03/2010] [Accepted: 02/19/2010] [Indexed: 11/21/2022]
Abstract
A growing body of evidence demonstrates the involvement of plasminogen activators (PAs) in a number of physiologic and pathologic events in the CNS. Induction of both tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) has been observed in different experimental models of epilepsy and tPA has been implicated in the mechanisms underlying seizure activity. We investigated the expression and the cellular distribution of tPA and uPA in several epileptogenic pathologies, including hippocampal sclerosis (HS; n=6), and developmental glioneuronal lesions, such as focal cortical dysplasia (FCD, n=6), cortical tubers in patients with the tuberous sclerosis complex (TSC; n=6) and in gangliogliomas (GG; n=6), using immuno-cytochemical, western blot and real-time quantitative PCR analysis. TPA and uPA immunostaining showed increased expression within the epileptogenic lesions compared to control specimens in both glial and neuronal cells (hippocampal neurons in HS and dysplastic neurons in FCD, TSC and GG specimens). Confocal laser scanning microscopy confirmed expression of both proteins in astrocytes and microglia, as well as in microvascular endothelium. Immunoblot demonstrated also up-regulation of the uPA receptor (uPAR; P<0.05). Increased expression of tPA, uPA, uPAR and tissue PA inhibitor type mRNA levels was also detected by PCR analysis in different epileptogenic pathologies (P<0.05). Our data support the role of PA system components in different human focal epileptogenic pathologies, which may critically influence neuronal activity, inflammatory response, as well as contributing to the complex remodeling of the neuronal networks occurring in epileptogenic lesions.
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Bae MH, Bissonette GB, Mars WM, Michalopoulos GK, Achim CL, Depireux DA, Powell EM. Hepatocyte growth factor (HGF) modulates GABAergic inhibition and seizure susceptibility. Exp Neurol 2009; 221:129-35. [PMID: 19853606 DOI: 10.1016/j.expneurol.2009.10.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 10/10/2009] [Accepted: 10/15/2009] [Indexed: 01/18/2023]
Abstract
Disrupted ontogeny of forebrain inhibitory interneurons leads to neurological disorders, including epilepsy. Adult mice lacking the urokinase plasminogen activator receptor (Plaur) have decreased numbers of neocortical GABAergic interneurons and spontaneous seizures, attributed to a reduction of hepatocyte growth factor/scatter factor (HGF/SF). We report that by increasing endogenous HGF/SF concentration in the postnatal Plaur null mouse brain maintains the interneuron populations in the adult, reverses the seizure behavior and stabilizes the spontaneous electroencephalogram activity. The perinatal intervention provides a pathway to reverse potential birth defects and ameliorate seizures in the adult.
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Affiliation(s)
- Mihyun H Bae
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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32
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Expression of urokinase-type plasminogen activator receptor is increased during epileptogenesis in the rat hippocampus. Neuroscience 2009; 163:316-28. [DOI: 10.1016/j.neuroscience.2009.06.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 05/24/2009] [Accepted: 06/09/2009] [Indexed: 12/30/2022]
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Campbell DB, Li C, Sutcliffe JS, Persico AM, Levitt P. Genetic evidence implicating multiple genes in the MET receptor tyrosine kinase pathway in autism spectrum disorder. Autism Res 2009; 1:159-68. [PMID: 19360663 DOI: 10.1002/aur.27] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A functional promoter variant of the gene encoding the MET receptor tyrosine kinase alters SP1 and SUB1 transcription factor binding, and is associated with autism spectrum disorder (ASD). Recent analyses of postmortem cerebral cortex from ASD patients revealed altered expression of MET protein and three transcripts encoding proteins that regulate MET signaling, hepatocyte growth factor (HGF), urokinase plasminogen activator receptor (PLAUR) and plasminogen activator inhibitor-1 (SERPINE1). To address potential risk conferred by multiple genes in the MET signaling pathway, we screened all exons and 5' promoter regions for variants in the five genes encoding proteins that regulate MET expression and activity. Identified variants were genotyped in 664 families (2,712 individuals including 1,228 with ASD) and 312 unrelated controls. Replicating our initial findings, family-based association test (FBAT) analyses demonstrated that the MET promoter variant rs1858830 C allele was associated with ASD in 101 new families (P=0.033). Two other genes in the MET signaling pathway also may confer risk. A haplotype of the SERPINE1 gene exhibited significant association. In addition, the PLAUR promoter variant rs344781 T allele was associated with ASD by both FBAT (P=0.006) and case-control analyses (P=0.007). The PLAUR promoter rs344781 relative risk was 1.93 (95% confidence interval [CI]: 1.12-3.31) for genotype TT and 2.42 (95% CI: 1.38-4.25) for genotype CT compared to genotype CC. Gene-gene interaction analyses suggested a significant interaction between MET and PLAUR. These data further support our hypothesis that genetic susceptibility impacting multiple components of the MET signaling pathway contributes to ASD risk.
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Affiliation(s)
- Daniel B Campbell
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, USA.
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Levitt P, Campbell DB. The genetic and neurobiologic compass points toward common signaling dysfunctions in autism spectrum disorders. J Clin Invest 2009; 119:747-54. [PMID: 19339766 DOI: 10.1172/jci37934] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Autism spectrum disorder (ASD) is a common neurodevelopmental disorder with high heritability. Here, we discuss data supporting the view that there are at least two distinct genetic etiologies for ASD: rare, private (de novo) single gene mutations that may have a large effect in causing ASD; and inherited, common functional variants of a combination of genes, each having a small to moderate effect in increasing ASD risk. It also is possible that a combination of the two mechanisms may occur in some individuals with ASD. We further discuss evidence from individuals with a number of different neurodevelopmental syndromes, in which there is a high prevalence of ASD, that some private mutations and common variants converge on dysfunctional ERK and PI3K signaling, which negatively impacts neurodevelopmental events regulated by some receptor tyrosine kinases.
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Affiliation(s)
- Pat Levitt
- Vanderbilt Kennedy Center for Research on Human Development and Department of Pharmacology,Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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35
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Tjwa M, Sidenius N, Moura R, Jansen S, Theunissen K, Andolfo A, De Mol M, Dewerchin M, Moons L, Blasi F, Verfaillie C, Carmeliet P. Membrane-anchored uPAR regulates the proliferation, marrow pool size, engraftment, and mobilization of mouse hematopoietic stem/progenitor cells. J Clin Invest 2009; 119:1008-18. [PMID: 19273908 DOI: 10.1172/jci36010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Accepted: 01/14/2009] [Indexed: 01/17/2023] Open
Abstract
The mechanisms of BM hematopoietic stem/progenitor cell (HSPC) adhesion, engraftment, and mobilization remain incompletely identified. Here, using WT and transgenic mice, we have shown that membrane-anchored plasminogen activator, urokinase receptor (MuPAR) marks a subset of HSPCs and promotes the preservation of the size of this pool of cells in the BM. Loss or inhibition of MuPAR increased HSPC proliferation and impaired their homing, engraftment, and adhesion to the BM microenvironment. During mobilization, MuPAR was inactivated by plasmin via proteolytic cleavage. Cell-autonomous loss of the gene encoding MuPAR also impaired long-term engraftment and multilineage repopulation in primary and secondary recipient mice. These findings identify MuPAR and plasmin as regulators of the proliferation, marrow pool size, homing, engraftment, and mobilization of HSPCs and possibly also of HSCs.
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Affiliation(s)
- Marc Tjwa
- VIB--Vesalius Research Center, Katholieke Universiteit Leuven, Leuven, Belgium
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Campbell DB, Buie TM, Winter H, Bauman M, Sutcliffe JS, Perrin JM, Levitt P. Distinct genetic risk based on association of MET in families with co-occurring autism and gastrointestinal conditions. Pediatrics 2009; 123:1018-24. [PMID: 19255034 DOI: 10.1542/peds.2008-0819] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE In addition to the core behavioral symptoms of autism spectrum disorder, many patients present with complex medical conditions including gastrointestinal dysfunction. A functional variant in the promoter of the gene encoding the MET receptor tyrosine kinase is associated with autism spectrum disorder, and MET protein expression is decreased in the temporal cortex of subjects with autism spectrum disorder. MET is a pleiotropic receptor that functions in both brain development and gastrointestinal repair. On the basis of these functions, we hypothesized that association of the autism spectrum disorder-associated MET promoter variant may be enriched in a subset of individuals with co-occurring autism spectrum disorder and gastrointestinal conditions. PATIENTS AND METHODS Subjects were 918 individuals from 214 Autism Genetics Resource Exchange families with a complete medical history including gastrointestinal condition report. Genotypes at the autism spectrum disorder-associated MET promoter variant rs1858830 were determined. Family-based association test and chi(2) analyses were used to determine the association of MET rs1858830 alleles with autism spectrum disorder and the presence of gastrointestinal conditions. RESULTS In the entire 214-family sample, the MET rs1858830 C allele was associated with both autism spectrum disorder and gastrointestinal conditions. Stratification by the presence of gastrointestinal conditions revealed that the MET C allele was associated with both autism spectrum disorder and gastrointestinal conditions in 118 families containing at least 1 child with co-occurring autism spectrum disorder and gastrointestinal conditions. In contrast, there was no association of the MET polymorphism with autism spectrum disorder in the 96 families lacking a child with co-occurring autism spectrum disorder and gastrointestinal conditions. chi(2) analyses of MET rs1858830 genotypes indicated over-representation of the C allele in individuals with co-occurring autism spectrum disorder and gastrointestinal conditions compared with non-autism spectrum disorder siblings, parents, and unrelated controls. CONCLUSION These results suggest that disrupted MET signaling may contribute to increased risk for autism spectrum disorder that includes familial gastrointestinal dysfunction.
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Affiliation(s)
- Daniel B Campbell
- Vanderbilt University, 8114 MRB3, 465 21st Ave South, Nashville, TN 37232, USA.
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Royer-Zemmour B, Ponsole-Lenfant M, Gara H, Roll P, Lévêque C, Massacrier A, Ferracci G, Cillario J, Robaglia-Schlupp A, Vincentelli R, Cau P, Szepetowski P. Epileptic and developmental disorders of the speech cortex: ligand/receptor interaction of wild-type and mutant SRPX2 with the plasminogen activator receptor uPAR. Hum Mol Genet 2008; 17:3617-30. [PMID: 18718938 DOI: 10.1093/hmg/ddn256] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Mutations in SRPX2 (Sushi-Repeat Protein, X-linked 2) cause rolandic epilepsy with speech impairment (RESDX syndrome) or with altered development of the speech cortex (bilateral perisylvian polymicrogyria). The physiological roles of SRPX2 remain unknown to date. One way to infer the function of SRPX2 relies on the identification of the as yet unknown SRPX2 protein partners. Using a combination of interactome approaches including yeast two-hybrid screening, co-immunoprecipitation experiments, cell surface binding and surface plasmon resonance (SPR), we show that SRPX2 is a ligand for uPAR, the urokinase-type plasminogen activator (uPA) receptor. Previous studies have shown that uPAR(-/-) knock-out mice exhibited enhanced susceptibility to epileptic seizures and had brain cortical anomalies consistent with altered neuronal migration and maturation, all features that are reminiscent to the phenotypes caused by SRPX2 mutations. SPR analysis indicated that the p.Y72S mutation associated with rolandic epilepsy and perisylvian polymicrogyria, led to a 5.8-fold gain-of-affinity of SRPX2 with uPAR. uPAR is a crucial component of the extracellular plasminogen proteolysis system; two more SRPX2 partners identified here, the cysteine protease cathepsin B (CTSB) and the metalloproteinase ADAMTS4, are also components of the extracellular proteolysis machinery and CTSB is a well-known activator of uPA. The identification of functionally related SRPX2 partners provides the first and exciting insights into the possible role of SRPX2 in the brain, and suggests that a network of SRPX2-interacting proteins classically involved in the proteolytic remodeling of the extracellular matrix and including uPAR participates in the functioning, in the development and in disorders of the speech cortex.
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Zhang G, Eddy AA. Urokinase and its receptors in chronic kidney disease. FRONTIERS IN BIOSCIENCE : A JOURNAL AND VIRTUAL LIBRARY 2008; 13:5462-78. [PMID: 18508599 PMCID: PMC3142275 DOI: 10.2741/3093] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review focuses on the role of the serine protease urokinase-type plasminogen activator and its high affinity receptor uPAR/CD87 in chronic kidney disease (CKD) progression. An emerging theme is their organ- and site-specific effects. In addition to tubules, uPA is produced by macrophages and fibroblasts in CKD. By activating hepatocyte growth factor and degrading fibrinogen uPA may have anti-fibrotic effects. However renal fibrosis was similar between uPA wild-type and knockout mice in experimental CKD. The uPAR is expressed by renal parenchymal cells and inflammatory cells in a variety of kidney diseases. Such expression appears anti-fibrotic based on studies in uPAR-deficient mice. In CKD uPAR expression is associated with higher uPA activity but its most important effect appears to be due to effects on cell recruitment and migration that involve interactions with a variety of co-receptors and chemoattractant effects of soluble uPAR. Vitronectin and high molecular weight kininogen are alternate uPAR ligands, and receptors in addition to uPAR may also bind directly to uPA and activate cell signaling pathways.
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Affiliation(s)
- Guoqiang Zhang
- University of Washington and Children's Hospital and Regional Medical Center, Division of Nephrology, 4800 Sand Point Way NE, Seattle, WA 98105, USA
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Gutova M, Najbauer J, Frank RT, Kendall SE, Gevorgyan A, Metz MZ, Guevorkian M, Edmiston M, Zhao D, Glackin CA, Kim SU, Aboody KS. Urokinase plasminogen activator and urokinase plasminogen activator receptor mediate human stem cell tropism to malignant solid tumors. Stem Cells 2008; 26:1406-13. [PMID: 18403751 DOI: 10.1634/stemcells.2008-0141] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Human neural and mesenchymal stem cells have been identified for cell-based therapies in regenerative medicine and as vehicles for delivering therapeutic agents to areas of injury and tumors. However, the signals required for homing and recruitment of stem cells to these sites are not well understood. Urokinase plasminogen activator (uPA) and urokinase plasminogen activator receptor (uPAR) are involved in chemotaxis and cell guidance during normal development and are upregulated in invasive tumors. Here we provided evidence that activation of uPA and uPAR in malignant solid tumors (brain, lung, prostate, and breast) augments neural and mesenchymal stem cell tropism. Expression levels of uPAR on human solid tumor cell lines correlated with levels of uPA and soluble uPAR in tumor cell-conditioned media. Cytokine expression profiles of these tumor-conditioned media were determined by protein arrays. Among 79 cytokines investigated, interleukin (IL)-6, IL-8, and monocyte chemoattractant protein-1 were the most highly expressed cytokines in uPAR-positive tumors. We provided evidence that human recombinant uPA induced stem cell migration, whereas depletion of uPA from PC-3 prostate cancer cell-conditioned medium blocked stem cell migration. Furthermore, retrovirus-mediated overexpression of uPA and uPAR in neuroblastoma (NB1691) cells induced robust migration of stem cells toward NB1691 cell-conditioned media, compared with media derived from wild-type NB1691 cells. We conclude that expression of uPA and uPAR in cancer cells underlies a novel mechanism of stem cell tropism to malignant solid tumors, which may be important for development of optimal stem cell-based therapies. Disclosure of potential conflicts of interest is found at the end of this article.
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Affiliation(s)
- Margarita Gutova
- Division of Hematology/Hematopoietic Cell Transplantation, City of Hope National Medical Center and Beckman Research Institute, 1500 East Duarte Road, Duarte, California 91010-3000, USA.
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Glickstein SB, Moore H, Slowinska B, Racchumi J, Suh M, Chuhma N, Ross ME. Selective cortical interneuron and GABA deficits in cyclin D2-null mice. Development 2008; 134:4083-93. [PMID: 17965053 DOI: 10.1242/dev.008524] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In contrast to cyclin D1 nulls (cD1-/-), mice without cyclin D2 (cD2-/-) lack cerebellar stellate interneurons; the reason for this is unknown. In the present study in cortex, we found a disproportionate loss of parvalbumin (PV) interneurons in cD2-/- mice. This selective reduction in PV subtypes was associated with reduced frequency of GABA-mediated inhibitory postsynaptic currents in pyramidal neurons, as measured by voltage-clamp recordings, and increased cortical sharp activity in the EEGs of awake-behaving cD2-/- mice. Cell cycle regulation was examined in the medial ganglionic eminence (MGE), the major source of PV interneurons in mouse brain, and differences between cD2-/- and cD1-/- suggested that cD2 promotes subventricular zone (SVZ) divisions, exerting a stronger inhibitory influence on the p27 Cdk-inhibitor (Cdkn1b) to delay cell cycle exit of progenitors. We propose that cD2 promotes transit-amplifying divisions in the SVZ and that these ensure proper output of at least a subset of PV interneurons.
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Affiliation(s)
- Sara B Glickstein
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, NY 10065, USA
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Hansen TVO, Borup R, Marstrand T, Rehfeld JF, Nielsen FC. Cholecystokinin-2 receptor mediated gene expression in neuronal PC12 cells. J Neurochem 2007; 104:1450-65. [DOI: 10.1111/j.1471-4159.2007.05076.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Eagleson KL, Schlueter McFadyen-Ketchum LJ, Ahrens ET, Mills PH, Does MD, Nickols J, Levitt P. Disruption of Foxg1 expression by knock-in of cre recombinase: effects on the development of the mouse telencephalon. Neuroscience 2007; 148:385-99. [PMID: 17640820 PMCID: PMC2194757 DOI: 10.1016/j.neuroscience.2007.06.012] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Accepted: 06/03/2007] [Indexed: 01/19/2023]
Abstract
The cre/loxP system is used routinely to manipulate gene expression in the mouse nervous system. In order to delete genes specifically from the telencephalon, the Foxg1-cre line was created previously by replacing the intron-less Foxg1 coding region with cre, resulting in a Foxg1 heterozygous mouse. As the telencephalon of heterozygous Foxg1 mice was reported to be normal, this genotype often has been used as the control in subsequent analyses. Here we describe substantial disruption of forebrain development of heterozygous mice in the Foxg1-cre line, maintained on the C57BL/6J background. High resolution magnetic resonance microscopy reveals a significant reduction in the volume of the neocortex, hippocampus and striatum. The alteration in the neocortex results, in part, from a decrease in its tangential dimension, although gross patterning of the cortical sheet appears normal. This decrease is observed in three different Foxg1 heterozygous mouse lines, independent of the method of achieving deletion of the Foxg1 gene. Although Foxg1 is not expressed in the diencephalon, three-dimensional magnetic resonance microscopy revealed that thalamic volume in the adult is reduced. In contrast, at postnatal day 4, thalamic volume is normal, suggesting that interactions between cortex and dorsal thalamus postnatally produce the final adult thalamic phenotype. In the Foxg1-cre line maintained on the C57BL/6J background, the radial domain of the cerebral cortex also is disrupted substantially, particularly in supragranular layers. However, neither Foxg1 heterozygous mice of the Foxg1-tet (tetracycline transactivator) line, nor those of the Foxg1-lacZ and Foxg1-cre lines maintained on a mixed background, displayed a reduced cortical thickness. Thus Cre recombinase contributes to the radial phenotype, although only in the context of the congenic C57BL/6J background. These observations highlight an important role for Foxg1 in cortical development, reveal noteworthy complexity in the invocation of specific mechanisms underlying phenotypes expressed following genetic manipulations and stress the importance of including appropriate controls of all genotypes.
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Affiliation(s)
- K L Eagleson
- Vanderbilt Kennedy Center for Research on Human Development and Department of Pharmacology, Vanderbilt University School of Medicine, 8110B Medical Research Building III, 465 21st Avenue South, Nashville, TN 37232, USA.
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Abstract
Interneurons are GABAergic neurons responsible for inhibitory activity in the adult hippocampus, thereby controlling the activity of principal excitatory cells through the activation of postsynaptic GABAA receptors. Subgroups of GABAergic neurons innervate specific parts of excitatory neurons. This specificity indicates that particular interneuron subgroups are able to recognize molecules segregated on the membrane of the pyramidal neuron. Once these specific connections are established, a quantitative regulation of their strength must be performed to achieve the proper balance of excitation and inhibition. We will review when and where interneurons are generated. We will then detail their migration toward and within the hippocampus, and the maturation of their morphological and neurochemical characteristics. We will finally review potential mechanisms underlying the development of GABAergic interneurons.
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Affiliation(s)
- Lydia Danglot
- Laboratoire de Biologie de la Synapse Normale et Pathologique, Unité Inserm U789, Ecole Normale Supérieure, 46 rue d'Ulm, 75005 Paris, France.
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Geschwind DH, Levitt P. Autism spectrum disorders: developmental disconnection syndromes. Curr Opin Neurobiol 2007; 17:103-11. [PMID: 17275283 DOI: 10.1016/j.conb.2007.01.009] [Citation(s) in RCA: 950] [Impact Index Per Article: 55.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Accepted: 01/19/2007] [Indexed: 01/15/2023]
Abstract
Autism is a common and heterogeneous childhood neurodevelopmental disorder. Analogous to broad syndromes such as mental retardation, autism has many etiologies and should be considered not as a single disorder but, rather, as 'the autisms'. However, recent genetic findings, coupled with emerging anatomical and functional imaging studies, suggest a potential unifying model in which higher-order association areas of the brain that normally connect to the frontal lobe are partially disconnected during development. This concept of developmental disconnection can accommodate the specific neurobehavioral features that are observed in autism, their emergence during development, and the heterogeneity of autism etiology, behaviors and cognition.
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Affiliation(s)
- Daniel H Geschwind
- Program in Neurogenetics, Department of Neurology and Semel Institute, David Geffen School of Medicine at University of California Los Angeles, 710 Westwood Plaza, Los Angeles, CA 90095, USA.
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Abstract
Disruption of gamma-aminobutyric acid (GABAergic) interneuron development during the embryonic and early postnatal periods can have profound neurological and behavioral consequences. Hepatocyte growth factor/scatter factor (HGF/SF) has been identified as an important molecular cue that may guide the movement of interneurons from their birthplace in the ganglionic eminences (GE) to their final resting place in the neocortex. In vitro studies demonstrate that decreased HGF/SF bioactivity in pallial and subpallial tissues is associated with a reduction in the number of cells migrating out of GE explants. The uPAR knockout mouse provides a unique opportunity to study the effects of interneuron disruption in vivo. uPAR-/- mice have reduced HGF/SF bioactivity in the GE during the period of interneuron development and a concomitant 50% reduction in the number of GABAergic interneurons seeding frontal and parietal regions of the cerebral cortex. Behaviorally, these mice display an increased susceptibility to seizures, heightened anxiety, and diminished social interaction. This article discusses the commonalities between the functional defects seen in uPAR-/- mice and those of humans with developmental disorders, such as epilepsy, schizophrenia, and autism. It is suggested that disruption of GABAergic interneuron development may represent a common point of convergence underlying the etiologies of many of these developmental disorders.
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Affiliation(s)
- Pat Levitt
- Vanderbilt University, Vanderbilt Kennedy Center for Research on Human Development, Nashville, Tennessee 37203, USA.
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