1
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Zhang T, Ai D, Wei P, Xu Y, Bi Z, Ma F, Li F, Chen XJ, Zhang Z, Zou X, Guo Z, Zhao Y, Li JL, Ye M, Feng Z, Zhang X, Zheng L, Yu J, Li C, Tu T, Zeng H, Lei J, Zhang H, Hong T, Zhang L, Luo B, Li Z, Xing C, Jia C, Li L, Sun W, Ge WP. The subcommissural organ regulates brain development via secreted peptides. Nat Neurosci 2024; 27:1103-1115. [PMID: 38741020 DOI: 10.1038/s41593-024-01639-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 04/03/2024] [Indexed: 05/16/2024]
Abstract
The subcommissural organ (SCO) is a gland located at the entrance of the aqueduct of Sylvius in the brain. It exists in species as distantly related as amphioxus and humans, but its function is largely unknown. Here, to explore its function, we compared transcriptomes of SCO and non-SCO brain regions and found three genes, Sspo, Car3 and Spdef, that are highly expressed in the SCO. Mouse strains expressing Cre recombinase from endogenous promoter/enhancer elements of these genes were used to genetically ablate SCO cells during embryonic development, resulting in severe hydrocephalus and defects in neuronal migration and development of neuronal axons and dendrites. Unbiased peptidomic analysis revealed enrichment of three SCO-derived peptides, namely, thymosin beta 4, thymosin beta 10 and NP24, and their reintroduction into SCO-ablated brain ventricles substantially rescued developmental defects. Together, these data identify a critical role for the SCO in brain development.
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Affiliation(s)
- Tingting Zhang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Chinese Institute for Brain Research, Beijing, China
| | - Daosheng Ai
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Chinese Institute for Brain Research, Beijing, China
| | - Pingli Wei
- Department of Chemistry and School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
| | - Ying Xu
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- State Key Laboratory of Proteomics, National Center for Protein Sciences-Beijing, Beijing Proteome Research Center, Beijing Institute of Lifeomics, Beijing, China
| | - Zhanying Bi
- Chinese Institute for Brain Research, Beijing, China
- College of Life Sciences, Nankai University, Tianjin, China
| | - Fengfei Ma
- Department of Chemistry and School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
| | - Fengzhi Li
- Chinese Institute for Brain Research, Beijing, China
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Xing-Jun Chen
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Chinese Institute for Brain Research, Beijing, China
| | - Zhaohuan Zhang
- Department of Laboratory Medicine, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Xiaoxiao Zou
- Chinese Institute for Brain Research, Beijing, China
- Changping Laboratory, Beijing, China
| | - Zongpei Guo
- Chinese Institute for Brain Research, Beijing, China
| | - Yue Zhao
- Chinese Institute for Brain Research, Beijing, China
| | - Jun-Liszt Li
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Chinese Institute for Brain Research, Beijing, China
| | - Meng Ye
- Chinese Institute for Brain Research, Beijing, China
- Changping Laboratory, Beijing, China
- School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Ziyan Feng
- Chinese Institute for Brain Research, Beijing, China
| | | | - Lijun Zheng
- Chinese Institute for Brain Research, Beijing, China
- School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Jie Yu
- Chinese Institute for Brain Research, Beijing, China
- Department of Neurology, First Affiliated Hospital, School of Medicine, Zhejiang University, Zhejiang, China
| | - Chunli Li
- National Institute of Biological Sciences, Beijing, China
| | - Tianqi Tu
- Department of Neurosurgery, Xuanwu Hospital, China International Neuroscience Institute, Capital Medical University, Beijing, China
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Jianfeng Lei
- Medical Imaging laboratory of Core Facility Center, Capital Medical University, Beijing, China
| | - Hongqi Zhang
- Department of Neurosurgery, Xuanwu Hospital, China International Neuroscience Institute, Capital Medical University, Beijing, China
| | - Tao Hong
- Department of Neurosurgery, Xuanwu Hospital, China International Neuroscience Institute, Capital Medical University, Beijing, China
| | - Li Zhang
- Chinese Institute for Brain Research, Beijing, China
| | - Benyan Luo
- Department of Neurology, First Affiliated Hospital, School of Medicine, Zhejiang University, Zhejiang, China
| | - Zhen Li
- Chinese Institute for Brain Research, Beijing, China
| | - Chao Xing
- Eugene McDermott Center for Human Growth and Development, Department of Bioinformatics, School of Public Health, UT Southwestern Medical Center, Dallas, TX, USA
| | - Chenxi Jia
- State Key Laboratory of Proteomics, National Center for Protein Sciences-Beijing, Beijing Proteome Research Center, Beijing Institute of Lifeomics, Beijing, China
| | - Lingjun Li
- Department of Chemistry and School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA.
| | - Wenzhi Sun
- Chinese Institute for Brain Research, Beijing, China.
- School of Basic Medical Sciences, Capital Medical University, Beijing, China.
| | - Woo-Ping Ge
- Chinese Institute for Brain Research, Beijing, China.
- Changping Laboratory, Beijing, China.
- Department of Neurosurgery, Xuanwu Hospital, China International Neuroscience Institute, Capital Medical University, Beijing, China.
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2
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Zhang T, Ai D, Wei P, Xu Y, Bi Z, Ma F, Li F, Chen XJ, Zhang Z, Zou X, Guo Z, Zhao Y, Li JL, Ye M, Feng Z, Zhang X, Zheng L, Yu J, Li C, Tu T, Zeng H, Lei J, Zhang H, Hong T, Zhang L, Luo B, Li Z, Xing C, Jia C, Li L, Sun W, Ge WP. The subcommissural organ regulates brain development via secreted peptides. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.30.587415. [PMID: 38585720 PMCID: PMC10996762 DOI: 10.1101/2024.03.30.587415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
The subcommissural organ (SCO) is a gland located at the entrance of the aqueduct of Sylvius in the brain. It exists in species as distantly related as amphioxus and humans, but its function is largely unknown. To explore its function, we compared transcriptomes of SCO and non-SCO brain regions and found three genes, Sspo, Car3, and Spdef, that are highly expressed in the SCO. Mouse strains expressing Cre recombinase from endogenous promoter/enhancer elements of these genes were used to genetically ablate SCO cells during embryonic development, resulting in severe hydrocephalus and defects in neuronal migration and development of neuronal axons and dendrites. Unbiased peptidomic analysis revealed enrichment of three SCO-derived peptides, namely thymosin beta 4, thymosin beta 10, and NP24, and their reintroduction into SCO-ablated brain ventricles substantially rescued developmental defects. Together, these data identify a critical role for the SCO in brain development.
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Affiliation(s)
- Tingting Zhang
- Academy for Advanced Interdisciplinary Studies (AAIS), Peking University, Beijing 100871, China
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
| | - Daosheng Ai
- Academy for Advanced Interdisciplinary Studies (AAIS), Peking University, Beijing 100871, China
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
| | - Pingli Wei
- Department of Chemistry and School of Pharmacy, University of Wisconsin-Madison, Wisconsin 53705, USA
| | - Ying Xu
- School of Basic Medical Sciences, Anhui Medical University, Hefei 230032, China
- State Key Laboratory of Proteomics, National Center for Protein Sciences-Beijing, Beijing Proteome Research Center, Beijing Institute of Lifeomics, Beijing 102206, China
| | - Zhanying Bi
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Fengfei Ma
- Department of Chemistry and School of Pharmacy, University of Wisconsin-Madison, Wisconsin 53705, USA
| | - Fengzhi Li
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
- Beijing Normal University, State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing 100875, China
| | - Xing-jun Chen
- Academy for Advanced Interdisciplinary Studies (AAIS), Peking University, Beijing 100871, China
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
| | - Zhaohuan Zhang
- Department of Laboratory Medicine, Changzheng Hospital, Naval Medical University, Shanghai 200003, China
| | - Xiaoxiao Zou
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
- Changping Laboratory, Beijing 102206, China
| | - Zongpei Guo
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
| | - Yue Zhao
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
| | - Jun-Liszt Li
- Academy for Advanced Interdisciplinary Studies (AAIS), Peking University, Beijing 100871, China
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
| | - Meng Ye
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
- School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
- Changping Laboratory, Beijing 102206, China
| | - Ziyan Feng
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
| | - Xinshuang Zhang
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
| | - Lijun Zheng
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
- School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Jie Yu
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
- Department of Neurology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Chunli Li
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Tianqi Tu
- Department of Neurosurgery, Xuanwu Hospital, China International Neuroscience Institute, Capital Medical University, Beijing 100053, China
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, Washington 98109, USA
| | - Jianfeng Lei
- Medical Imaging laboratory of Core Facility Center, Capital Medical University, Beijing 100054, China
| | - Hongqi Zhang
- Department of Neurosurgery, Xuanwu Hospital, China International Neuroscience Institute, Capital Medical University, Beijing 100053, China
| | - Tao Hong
- Department of Neurosurgery, Xuanwu Hospital, China International Neuroscience Institute, Capital Medical University, Beijing 100053, China
| | - Li Zhang
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
| | - Benyan Luo
- Department of Neurology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Zhen Li
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
| | - Chao Xing
- Eugene McDermott Center for Human Growth and Development, Department of Bioinformatics, School of Public Health, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Chenxi Jia
- State Key Laboratory of Proteomics, National Center for Protein Sciences-Beijing, Beijing Proteome Research Center, Beijing Institute of Lifeomics, Beijing 102206, China
| | - Lingjun Li
- Department of Chemistry and School of Pharmacy, University of Wisconsin-Madison, Wisconsin 53705, USA
| | - Wenzhi Sun
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
- School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Woo-ping Ge
- Chinese Institute for Brain Research, Beijing, Beijing 102206, China
- Department of Neurosurgery, Xuanwu Hospital, China International Neuroscience Institute, Capital Medical University, Beijing 100053, China
- Changping Laboratory, Beijing 102206, China
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Xu H, Dugué GP, Cantaut-Belarif Y, Lejeune FX, Gupta S, Wyart C, Lehtinen MK. SCO-spondin knockout mice exhibit small brain ventricles and mild spine deformation. Fluids Barriers CNS 2023; 20:89. [PMID: 38049798 PMCID: PMC10696872 DOI: 10.1186/s12987-023-00491-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/18/2023] [Indexed: 12/06/2023] Open
Abstract
Reissner's fiber (RF) is an extracellular polymer comprising the large monomeric protein SCO-spondin (SSPO) secreted by the subcommissural organ (SCO) that extends through cerebrospinal fluid (CSF)-filled ventricles into the central canal of the spinal cord. In zebrafish, RF and CSF-contacting neurons (CSF-cNs) form an axial sensory system that detects spinal curvature, instructs morphogenesis of the body axis, and enables proper alignment of the spine. In mammalian models, RF has been implicated in CSF circulation. However, challenges in manipulating Sspo, an exceptionally large gene of 15,719 nucleotides, with traditional approaches has limited progress. Here, we generated a Sspo knockout mouse model using CRISPR/Cas9-mediated genome-editing. Sspo knockout mice lacked RF-positive material in the SCO and fibrillar condensates in the brain ventricles. Remarkably, Sspo knockout brain ventricle sizes were reduced compared to littermate controls. Minor defects in thoracic spine curvature were detected in Sspo knockouts, which did not alter basic motor behaviors tested. Altogether, our work in mouse demonstrates that SSPO and RF regulate ventricle size during development but only moderately impact spine geometry.
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Affiliation(s)
- Huixin Xu
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Guillaume P Dugué
- Neurophysiology of Brain Circuits, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
| | - Yasmine Cantaut-Belarif
- Sorbonne Université, Paris Brain Institute (Institut du Cerveau, ICM), Institut National de la Santé et de la Recherche Médicale (INSERM) U1127, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche 7225, Assistance Publique-Hôpitaux de Paris (APHP), Campus Hospitalier Pitié-Salpêtrière, 47, bld Hospital, 75013, Paris, France
| | - François-Xavier Lejeune
- Sorbonne Université, Paris Brain Institute (Institut du Cerveau, ICM), Institut National de la Santé et de la Recherche Médicale (INSERM) U1127, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche 7225, Assistance Publique-Hôpitaux de Paris (APHP), Campus Hospitalier Pitié-Salpêtrière, 47, bld Hospital, 75013, Paris, France
| | - Suhasini Gupta
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Claire Wyart
- Sorbonne Université, Paris Brain Institute (Institut du Cerveau, ICM), Institut National de la Santé et de la Recherche Médicale (INSERM) U1127, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche 7225, Assistance Publique-Hôpitaux de Paris (APHP), Campus Hospitalier Pitié-Salpêtrière, 47, bld Hospital, 75013, Paris, France.
| | - Maria K Lehtinen
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
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4
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Nualart F, Cifuentes M, Ramírez E, Martínez F, Barahona MJ, Ferrada L, Saldivia N, Bongarzone ER, Thorens B, Salazar K. Hyperglycemia increases SCO-spondin and Wnt5a secretion into the cerebrospinal fluid to regulate ependymal cell beating and glucose sensing. PLoS Biol 2023; 21:e3002308. [PMID: 37733692 PMCID: PMC10513282 DOI: 10.1371/journal.pbio.3002308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 08/22/2023] [Indexed: 09/23/2023] Open
Abstract
Hyperglycemia increases glucose concentrations in the cerebrospinal fluid (CSF), activating glucose-sensing mechanisms and feeding behavior in the hypothalamus. Here, we discuss how hyperglycemia temporarily modifies ependymal cell ciliary beating to increase hypothalamic glucose sensing. A high level of glucose in the rat CSF stimulates glucose transporter 2 (GLUT2)-positive subcommissural organ (SCO) cells to release SCO-spondin into the dorsal third ventricle. Genetic inactivation of mice GLUT2 decreases hyperglycemia-induced SCO-spondin secretion. In addition, SCO cells secrete Wnt5a-positive vesicles; thus, Wnt5a and SCO-spondin are found at the apex of dorsal ependymal cilia to regulate ciliary beating. Frizzled-2 and ROR2 receptors, as well as specific proteoglycans, such as glypican/testican (essential for the interaction of Wnt5a with its receptors) and Cx43 coupling, were also analyzed in ependymal cells. Finally, we propose that the SCO-spondin/Wnt5a/Frizzled-2/Cx43 axis in ependymal cells regulates ciliary beating, a cyclic and adaptive signaling mechanism to control glucose sensing.
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Affiliation(s)
- Francisco Nualart
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
- Center for Advanced Microscopy CMA BIO BIO, University of Concepcion, Concepcion, Chile
| | - Manuel Cifuentes
- Department of Cell Biology, Genetics and Physiology, University of Malaga, Málaga Biomedical Research Institute and Nanomedicine Platform (IBIMA-BIONAND Platform), Malaga, Spain
| | - Eder Ramírez
- Center for Advanced Microscopy CMA BIO BIO, University of Concepcion, Concepcion, Chile
| | - Fernando Martínez
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
| | - María José Barahona
- Center for Advanced Microscopy CMA BIO BIO, University of Concepcion, Concepcion, Chile
| | - Luciano Ferrada
- Center for Advanced Microscopy CMA BIO BIO, University of Concepcion, Concepcion, Chile
| | - Natalia Saldivia
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
| | - Ernesto R. Bongarzone
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Bernard Thorens
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Katterine Salazar
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
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Xu H, Dugué GP, Cantaut-Belarif Y, Lejeune FX, Gupta S, Wyart C, Lehtinen MK. SCO-spondin knockout mice exhibit small brain ventricles and mild spine deformation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.01.551512. [PMID: 37577601 PMCID: PMC10418289 DOI: 10.1101/2023.08.01.551512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Reissner's fiber (RF) is an extracellular polymer comprising the large monomeric protein SCO-spondin (SSPO) secreted by the subcommissural organ (SCO) that extends through cerebrospinal fluid (CSF)-filled ventricles into the central canal of the spinal cord. In zebrafish, RF and CSF-contacting neurons (CSF-cNs) form an axial sensory system that detects spinal curvature, instructs morphogenesis of the body axis, and enables proper alignment of the spine. In mammalian models, RF has been implicated in CSF circulation. However, challenges in manipulating Sspo , an exceptionally large gene of 15,719 nucleotides, with traditional approaches has limited progress. Here, we generated a Sspo knockout mouse model using CRISPR/Cas9-mediated genome-editing. Sspo knockout mice lacked RF-positive material in the SCO and fibrillar condensates in the brain ventricles. Remarkably, Sspo knockout brain ventricle sizes were reduced compared to littermate controls. Minor defects in thoracic spine curvature were detected in Sspo knockouts, which did not alter basic motor behaviors tested. Altogether, our work in mouse demonstrates that SSPO and RF regulate ventricle size during development but only moderately impact spine geometry.
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6
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Sepúlveda V, Maurelia F, González M, Aguayo J, Caprile T. SCO-spondin, a giant matricellular protein that regulates cerebrospinal fluid activity. Fluids Barriers CNS 2021; 18:45. [PMID: 34600566 PMCID: PMC8487547 DOI: 10.1186/s12987-021-00277-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/11/2021] [Indexed: 12/28/2022] Open
Abstract
Cerebrospinal fluid is a clear fluid that occupies the ventricular and subarachnoid spaces within and around the brain and spinal cord. Cerebrospinal fluid is a dynamic signaling milieu that transports nutrients, waste materials and neuroactive substances that are crucial for the development, homeostasis and functionality of the central nervous system. The mechanisms that enable cerebrospinal fluid to simultaneously exert these homeostatic/dynamic functions are not fully understood. SCO-spondin is a large glycoprotein secreted since the early stages of development into the cerebrospinal fluid. Its domain architecture resembles a combination of a matricellular protein and the ligand-binding region of LDL receptor family. The matricellular proteins are a group of extracellular proteins with the capacity to interact with different molecules, such as growth factors, cytokines and cellular receptors; enabling the integration of information to modulate various physiological and pathological processes. In the same way, the LDL receptor family interacts with many ligands, including β-amyloid peptide and different growth factors. The domains similarity suggests that SCO-spondin is a matricellular protein enabled to bind, modulate, and transport different cerebrospinal fluid molecules. SCO-spondin can be found soluble or polymerized into a dynamic threadlike structure called the Reissner fiber, which extends from the diencephalon to the caudal tip of the spinal cord. Reissner fiber continuously moves caudally as new SCO-spondin molecules are added at the cephalic end and are disaggregated at the caudal end. This movement, like a conveyor belt, allows the transport of the bound molecules, thereby increasing their lifespan and action radius. The binding of SCO-spondin to some relevant molecules has already been reported; however, in this review we suggest more than 30 possible binding partners, including peptide β-amyloid and several growth factors. This new perspective characterizes SCO-spondin as a regulator of cerebrospinal fluid activity, explaining its high evolutionary conservation, its apparent multifunctionality, and the lethality or severe malformations, such as hydrocephalus and curved body axis, of knockout embryos. Understanding the regulation and identifying binding partners of SCO-spondin are crucial for better comprehension of cerebrospinal fluid physiology.
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Affiliation(s)
- Vania Sepúlveda
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Felipe Maurelia
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Maryori González
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Jaime Aguayo
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Teresa Caprile
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.
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7
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Rose CD, Pompili D, Henke K, Van Gennip JLM, Meyer-Miner A, Rana R, Gobron S, Harris MP, Nitz M, Ciruna B. SCO-Spondin Defects and Neuroinflammation Are Conserved Mechanisms Driving Spinal Deformity across Genetic Models of Idiopathic Scoliosis. Curr Biol 2020; 30:2363-2373.e6. [PMID: 32386528 DOI: 10.1016/j.cub.2020.04.020] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 03/05/2020] [Accepted: 04/08/2020] [Indexed: 12/23/2022]
Abstract
Adolescent idiopathic scoliosis (AIS) affects 3% to 4% of children between the ages of 11 and 18 [1, 2]. This disorder, characterized by abnormal three-dimensional spinal curvatures that typically develop during periods of rapid growth, occurs in the absence of congenital vertebral malformations or neuromuscular defects [1]. Genetic heterogeneity [3] and a historical lack of appropriate animal models [4] have confounded basic understanding of AIS biology; thus, treatment options remain limited [5, 6]. Recently, genetic studies using zebrafish have linked idiopathic-like scoliosis to irregularities in motile cilia-mediated cerebrospinal fluid flow [7-9]. However, because loss of cilia motility in human primary ciliary dyskinesia patients is not fully associated with scoliosis [10, 11], other pathogenic mechanisms remain to be determined. Here, we demonstrate that zebrafish scospondin (sspo) mutants develop late-onset idiopathic-like spinal curvatures in the absence of obvious cilia motility defects. Sspo is a large secreted glycoprotein functionally associated with the subcommissural organ and Reissner's fiber [12]-ancient and enigmatic organs of the brain ventricular system reported to govern cerebrospinal fluid homeostasis [13, 14], neurogenesis [12, 15-18], and embryonic morphogenesis [19]. We demonstrate that irregular deposition of Sspo within brain ventricles is associated with idiopathic-like scoliosis across diverse genetic models. Furthermore, Sspo defects are sufficient to induce oxidative stress and neuroinflammatory responses implicated in AIS pathogenesis [9]. Through screening for chemical suppressors of sspo mutant phenotypes, we also identify potent agents capable of blocking severe juvenile spine deformity. Our work thus defines a new preclinical model of AIS and provides tools to realize novel therapeutic strategies.
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Affiliation(s)
- Chloe D Rose
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, The University of Toronto, Toronto, ON M5S 1A8, Canada
| | - David Pompili
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, The University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Katrin Henke
- Department of Orthopedic Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Jenica L M Van Gennip
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, The University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Anne Meyer-Miner
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, The University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Rahul Rana
- Department of Chemistry, The University of Toronto, Toronto, ON M5S 3H6, Canada
| | | | - Matthew P Harris
- Department of Orthopedic Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Mark Nitz
- Department of Chemistry, The University of Toronto, Toronto, ON M5S 3H6, Canada
| | - Brian Ciruna
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, The University of Toronto, Toronto, ON M5S 1A8, Canada.
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8
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The subcommissural organ and the Reissner fiber: old friends revisited. Cell Tissue Res 2018; 375:507-529. [PMID: 30259139 DOI: 10.1007/s00441-018-2917-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/17/2018] [Indexed: 12/11/2022]
Abstract
The subcommissural organ (SCO) is an ancient and conserved brain gland secreting into cerebrospinal fluid (CSF) glycoproteins that form the Reissner fiber (RF). The present investigation was designed to further investigate the dynamic of the biosynthetic process of RF glycoproteins prior and after their release into the CSF, to identify the RF proteome and N-glycome and to clarify the mechanism of assembly of RF glycoproteins. Various methodological approaches were used: biosynthetic labelling injecting 35S-cysteine and 3H-galactose into the CSF, injection of antibodies against galectin-1 into the cerebrospinal fluid, light and electron microscopical methods; isolated bovine RF was used for proteome analyses by mass spectrometry and glycome analysis by xCGE-LIF. The biosynthetic labelling study further supported that a small pool of SCO-spondin molecules rapidly enter the secretory pathways after its synthesis, while most of the SCO-spondin molecules are stored in the rough endoplasmic reticulum for hours or days before entering the secretory pathway and being released to assemble into RF. The proteomic analysis of RF revealed clusterin and galectin-1 as partners of SCO-spondin; the in vivo use of anti-galectin-1 showed that this lectin is essential for the assembly of RF. Galectin-1 is not secreted by the SCO but evidence was obtained that it would be secreted by multiciliated ependymal cells lying close to the SCO. Further, a surprising variety and complexity of glycan structures were identified in the RF N-glycome that further expands the potential functions of RF to a level not previously envisaged. A model of the macromolecular organization of Reissner fiber is proposed.
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Cantaut-Belarif Y, Sternberg JR, Thouvenin O, Wyart C, Bardet PL. The Reissner Fiber in the Cerebrospinal Fluid Controls Morphogenesis of the Body Axis. Curr Biol 2018; 28:2479-2486.e4. [PMID: 30057305 PMCID: PMC6089837 DOI: 10.1016/j.cub.2018.05.079] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/15/2018] [Accepted: 05/25/2018] [Indexed: 01/12/2023]
Abstract
Organ development depends on the integration of coordinated long-range communication between cells. The cerebrospinal fluid composition and flow properties regulate several aspects of central nervous system development, including progenitor proliferation, neurogenesis, and migration [1-3]. One understudied component of the cerebrospinal fluid, described over a century ago in vertebrates, is the Reissner fiber. This extracellular thread forming early in development results from the assembly of the SCO-spondin protein in the third and fourth brain ventricles and central canal of the spinal cord [4]. Up to now, the function of the Reissner fiber has remained elusive, partly due to the lack of genetic invalidation models [4]. Here, by mutating the scospondin gene, we demonstrate that the Reissner fiber is critical for the morphogenesis of a straight posterior body axis. In zebrafish mutants where the Reissner fiber is lost, ciliogenesis and cerebrospinal fluid flow are intact but body axis morphogenesis is impaired. Our results also explain the frequently observed phenotype that mutant embryos with defective cilia exhibit defects in body axis curvature. Here, we reveal that these mutants systematically fail to assemble the Reissner fiber. We show that cilia promote the formation of the Reissner fiber and that the fiber is necessary for proper body axis morphogenesis. Our study sets the stage for future investigations of the mechanisms linking the Reissner fiber to the control of body axis curvature during vertebrate development.
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Affiliation(s)
- Yasmine Cantaut-Belarif
- Institut du Cerveau et de la Moelle Épinière (ICM), Inserm U 1127, CNRS UMR 7225, Sorbonne Université, 75013 Paris, France
| | - Jenna R Sternberg
- Institut du Cerveau et de la Moelle Épinière (ICM), Inserm U 1127, CNRS UMR 7225, Sorbonne Université, 75013 Paris, France
| | - Olivier Thouvenin
- Institut du Cerveau et de la Moelle Épinière (ICM), Inserm U 1127, CNRS UMR 7225, Sorbonne Université, 75013 Paris, France; Institut Langevin ESPCI, PSL Research University, CNRS UMR 7587, 1 Rue Jussieu, 75005 Paris, France
| | - Claire Wyart
- Institut du Cerveau et de la Moelle Épinière (ICM), Inserm U 1127, CNRS UMR 7225, Sorbonne Université, 75013 Paris, France.
| | - Pierre-Luc Bardet
- Institut du Cerveau et de la Moelle Épinière (ICM), Inserm U 1127, CNRS UMR 7225, Sorbonne Université, 75013 Paris, France.
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Abstract
UNLABELLED The glymphatic pathway expedites clearance of waste, including soluble amyloid β (Aβ) from the brain. Transport through this pathway is controlled by the brain's arousal level because, during sleep or anesthesia, the brain's interstitial space volume expands (compared with wakefulness), resulting in faster waste removal. Humans, as well as animals, exhibit different body postures during sleep, which may also affect waste removal. Therefore, not only the level of consciousness, but also body posture, might affect CSF-interstitial fluid (ISF) exchange efficiency. We used dynamic-contrast-enhanced MRI and kinetic modeling to quantify CSF-ISF exchange rates in anesthetized rodents' brains in supine, prone, or lateral positions. To validate the MRI data and to assess specifically the influence of body posture on clearance of Aβ, we used fluorescence microscopy and radioactive tracers, respectively. The analysis showed that glymphatic transport was most efficient in the lateral position compared with the supine or prone positions. In the prone position, in which the rat's head was in the most upright position (mimicking posture during the awake state), transport was characterized by "retention" of the tracer, slower clearance, and more CSF efflux along larger caliber cervical vessels. The optical imaging and radiotracer studies confirmed that glymphatic transport and Aβ clearance were superior in the lateral and supine positions. We propose that the most popular sleep posture (lateral) has evolved to optimize waste removal during sleep and that posture must be considered in diagnostic imaging procedures developed in the future to assess CSF-ISF transport in humans. SIGNIFICANCE STATEMENT The rodent brain removes waste better during sleep or anesthesia compared with the awake state. Animals exhibit different body posture during the awake and sleep states, which might affect the brain's waste removal efficiency. We investigated the influence of body posture on brainwide transport of inert tracers of anesthetized rodents. The major finding of our study was that waste, including Aβ, removal was most efficient in the lateral position (compared with the prone position), which mimics the natural resting/sleeping position of rodents. Although our finding awaits testing in humans, we speculate that the lateral position during sleep has advantage with regard to the removal of waste products including Aβ, because clinical studies have shown that sleep drives Aβ clearance from the brain.
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Sandoval M, Luarte A, Herrera-Molina R, Varas-Godoy M, Santibáñez M, Rubio FJ, Smit AB, Gundelfinger ED, Li KW, Smalla KH, Wyneken U. The glycolytic enzyme aldolase C is up-regulated in rat forebrain microsomes and in the cerebrospinal fluid after repetitive fluoxetine treatment. Brain Res 2013; 1520:1-14. [PMID: 23688545 DOI: 10.1016/j.brainres.2013.04.049] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 03/22/2013] [Accepted: 04/24/2013] [Indexed: 01/21/2023]
Abstract
The antidepressant drug fluoxetine is widely used for the treatment of a broad range of psychiatric disorders. Its mechanism of action is thought to involve cellular adaptations that are induced with a slow time course after initiation of treatment. To gain insight into the signaling pathways underlying such changes, the expression levels of proteins in a microsomal sub-fraction enriched in intracellular membranes from the rat forebrain was analyzed after two weeks of treatment with fluoxetine. Proteins were separated by two-dimensional gel electrophoresis, and the differentially regulated protein spots were identified by mass spectrometry. Protein network analysis suggested that most of the identified proteins could potentially be regulated by the insulin family of proteins. Among them, Fructose-bisphosphate aldolase C (AldoC), a glycolytic/gluconeogenic enzyme primarily expressed in forebrain astrocytes, was up-regulated 7.6-fold. An immunohistochemical analysis of the dorsal hippocampus revealed a robust decrease (43±2%) in the co-localization of AldoC and the astrocyte marker GFAP and a diffuse staining pattern, compatible with AldoC secretion into the extracellular space. Consistently, AldoC, contained in an exosome-like fraction in astrocyte conditioned medium, increased significantly in the cerebrospinal fluid. Our findings strongly favor a non-canonic signaling role for AldoC in cellular adaptations induced by repetitive fluoxetine treatment.
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Affiliation(s)
- Mauricio Sandoval
- Laboratorio de Neurociencias, Universidad de Los Andes, Santiago, Chile
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Role of the subcommissural organ in the pathogenesis of congenital hydrocephalus in the HTx rat. Cell Tissue Res 2013; 352:707-25. [PMID: 23640132 DOI: 10.1007/s00441-013-1615-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 03/08/2013] [Indexed: 01/05/2023]
Abstract
The present investigation was designed to clarify the role of the subcommissural organ (SCO) in the pathogenesis of hydrocephalus occurring in the HTx rat. The brains of non-affected and hydrocephalic HTx rats from embryonic day 15 (E15) to postnatal day 10 (PN10) were processed for electron microscopy, lectin binding and immunocytochemistry by using a series of antibodies. Cerebrospinal fluid (CSF) samples of non-affected and hydrocephalic HTx rats were collected at PN1, PN7 and PN30 and analysed by one- and two-dimensional electrophoresis, immunoblotting and nanoLC-ESI-MS/MS. A distinct malformation of the SCO is present as early as E15. Since stenosis of the Sylvius aqueduct (SA) occurs at E18 and dilation of the lateral ventricles starts at E19, the malformation of the SCO clearly precedes the onset of hydrocephalus. In the affected rats, the cephalic and caudal thirds of the SCO showed high secretory activity with all methods used, whereas the middle third showed no signs of secretion. At E18, the middle non-secretory third of the SCO progressively fused with the ventral wall of SA, resulting in marked aqueduct stenosis and severe hydrocephalus. The abnormal development of the SCO resulted in the permanent absence of Reissner's fibre (RF) and led to changes in the protein composition of the CSF. Since the SCO is the source of a large mass of sialilated glycoproteins that form the RF and of those that remain CSF-soluble, we hypothesize that the absence of this large mass of negatively charged molecules from the SA domain results in SA stenosis and impairs the bulk flow of CSF through the aqueduct.
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El Hiba O, Gamrani H, Ahboucha S. Increased Reissner's fiber material in the subcommissural organ and ventricular area in bile duct ligated rats. Acta Histochem 2012; 114:673-81. [PMID: 22209469 DOI: 10.1016/j.acthis.2011.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 11/29/2011] [Accepted: 11/30/2011] [Indexed: 12/23/2022]
Abstract
Hepatic encephalopathy is a common neuropsychiatric complication of acute and chronic liver failure. Whether brain structures with strategic positions in the interface of blood-brain barriers such as the circumventricular organs are involved in hepatic encephalopathy is not yet established. Among the circumventricular organs, the subcommissural organ secretes a glycoprotein known as Reissner's fiber, which condenses and forms an ever-growing thread-like structure into the cerebrospinal fluid. In the present work we describe the Reissner's fiber material within the subcommissural organ and its serotoninergic innervation in an animal model of chronic hepatic encephalopathy following bile duct ligation in experimental rats. The study involved immunohistochemical techniques with antibodies against Reissner's fiber and 5-hydroxytryptamine (5-HT). Four weeks after surgical bile duct ligation, a significant rise of Reissner's fiber immunoreactivity was observed in all subcommissural organ areas compared with controls. Moreover, significant Reissner's fiber immunoreactive materials within the ependyma and inside the parenchyma close to the ventricular borders were also seen in bile duct ligated rats, but not in control rats. Increased Reissner's fiber material in bile duct ligated rats seems to be related to a reduction of 5-HT innervation of the subcommissural organ, the ventricular borders and the nucleus of origin, the dorsal raphe nucleus. Our data describe alterations of the subcommissural organ/Reissner's fiber material and the subcommissural organ 5-HT innervation probably due to a general 5-HT deficit in bile duct ligated rats.
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Affiliation(s)
- Omar El Hiba
- Université Cadi Ayyad, Faculté des Sciences Semlalia, Équipe Neurosciences, Pharmacologie et Environnement, Marrakesh, Morocco
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Chatoui H, El Hiba O, Elgot A, Gamrani H. The rat SCO responsiveness to prolonged water deprivation: Implication of Reissner's fiber and serotonin system. C R Biol 2012; 335:253-60. [DOI: 10.1016/j.crvi.2012.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 03/24/2012] [Accepted: 03/25/2012] [Indexed: 10/28/2022]
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Czarnecka J, Roszek K, Jabłoński A, Smoliński DJ, Komoszyński M. Some aspects of purinergic signaling in the ventricular system of porcine brain. Acta Vet Scand 2011; 53:54. [PMID: 21995888 PMCID: PMC3213016 DOI: 10.1186/1751-0147-53-54] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 10/13/2011] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Numerous signaling pathways function in the brain ventricular system, including the most important - GABAergic, glutaminergic and dopaminergic signaling. Purinergic signalization system - comprising nucleotide receptors, nucleotidases, ATP and adenosine and their degradation products - are also present in the brain. However, the precise role of nucleotide signalling pathway in the ventricular system has been not elucidated so far. The aim of our research was the identification of all three elements of purinergic signaling pathway in the porcine brain ventricular system. RESULTS Besides nucleotide receptors on the ependymocytes surface, we studied purines and pyrimidines in the CSF, including mechanisms of nucleotide signaling in the swine model (Sus scrofa domestica). The results indicate presence of G proteins coupled P2Y receptors on ependymocytes and also P2X receptors engaged in fast signal transmission. Additionally we found in CSF nucleotides and adenosine in the concentration sufficient to P receptors activation. These extracellular nucleotides are metabolised by adenylate kinase and nucleotidases from at least two families: NTPDases and NPPases. A low activity of these nucleotide metabolising enzymes maintains nucleotides concentration in ventricular system in micromolar range. ATP is degraded into adenosine and inosine. CONCLUSIONS Our results confirm the thesis about cross-talking between brain and ventricular system functioning in physiological as well as pathological conditions. The close interaction of brain and ventricular system may elicit changes in qualitative and quantitative composition of purines and pyrimidines in CSF. These changes can be dependent on the physiological state of brain, including pathological processes in CNS.
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Stoop MP, Coulier L, Rosenling T, Shi S, Smolinska AM, Buydens L, Ampt K, Stingl C, Dane A, Muilwijk B, Luitwieler RL, Sillevis Smitt PAE, Hintzen RQ, Bischoff R, Wijmenga SS, Hankemeier T, van Gool AJ, Luider TM. Quantitative proteomics and metabolomics analysis of normal human cerebrospinal fluid samples. Mol Cell Proteomics 2011. [PMID: 20811074 DOI: 10.1074/mcp.m110.000877] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The analysis of cerebrospinal fluid (CSF) is used in biomarker discovery studies for various neurodegenerative central nervous system (CNS) disorders. However, little is known about variation of CSF proteins and metabolites between patients without neurological disorders. A baseline for a large number of CSF compounds appears to be lacking. To analyze the variation in CSF protein and metabolite abundances in a number of well-defined individual samples of patients undergoing routine, non-neurological surgical procedures, we determined the variation of various proteins and metabolites by multiple analytical platforms. A total of 126 common proteins were assessed for biological variations between individuals by ESI-Orbitrap. A large spread in inter-individual variation was observed (relative standard deviations [RSDs] ranged from 18 to 148%) for proteins with both high abundance and low abundance. Technical variation was between 15 and 30% for all 126 proteins. Metabolomics analysis was performed by means of GC-MS and nuclear magnetic resonance (NMR) imaging and amino acids were specifically analyzed by LC-MS/MS, resulting in the detection of more than 100 metabolites. The variation in the metabolome appears to be much more limited compared with the proteome: the observed RSDs ranged from 12 to 70%. Technical variation was less than 20% for almost all metabolites. Consequently, an understanding of the biological variation of proteins and metabolites in CSF of neurologically normal individuals appears to be essential for reliable interpretation of biomarker discovery studies for CNS disorders because such results may be influenced by natural inter-individual variations. Therefore, proteins and metabolites with high variation between individuals ought to be assessed with caution as candidate biomarkers because at least part of the difference observed between the diseased individuals and the controls will not be caused by the disease, but rather by the natural biological variation between individuals.
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Affiliation(s)
- Marcel P Stoop
- Department of Neurology, Erasmus University Medical Centre, Rotterdam, The Netherlands
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17
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Stoop MP, Coulier L, Rosenling T, Shi S, Smolinska AM, Buydens L, Ampt K, Stingl C, Dane A, Muilwijk B, Luitwieler RL, Sillevis Smitt PAE, Hintzen RQ, Bischoff R, Wijmenga SS, Hankemeier T, van Gool AJ, Luider TM. Quantitative proteomics and metabolomics analysis of normal human cerebrospinal fluid samples. Mol Cell Proteomics 2011; 9:2063-75. [PMID: 20811074 DOI: 10.1074/mcp.m900877-mcp200] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The analysis of cerebrospinal fluid (CSF) is used in biomarker discovery studies for various neurodegenerative central nervous system (CNS) disorders. However, little is known about variation of CSF proteins and metabolites between patients without neurological disorders. A baseline for a large number of CSF compounds appears to be lacking. To analyze the variation in CSF protein and metabolite abundances in a number of well-defined individual samples of patients undergoing routine, non-neurological surgical procedures, we determined the variation of various proteins and metabolites by multiple analytical platforms. A total of 126 common proteins were assessed for biological variations between individuals by ESI-Orbitrap. A large spread in inter-individual variation was observed (relative standard deviations [RSDs] ranged from 18 to 148%) for proteins with both high abundance and low abundance. Technical variation was between 15 and 30% for all 126 proteins. Metabolomics analysis was performed by means of GC-MS and nuclear magnetic resonance (NMR) imaging and amino acids were specifically analyzed by LC-MS/MS, resulting in the detection of more than 100 metabolites. The variation in the metabolome appears to be much more limited compared with the proteome: the observed RSDs ranged from 12 to 70%. Technical variation was less than 20% for almost all metabolites. Consequently, an understanding of the biological variation of proteins and metabolites in CSF of neurologically normal individuals appears to be essential for reliable interpretation of biomarker discovery studies for CNS disorders because such results may be influenced by natural inter-individual variations. Therefore, proteins and metabolites with high variation between individuals ought to be assessed with caution as candidate biomarkers because at least part of the difference observed between the diseased individuals and the controls will not be caused by the disease, but rather by the natural biological variation between individuals.
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Affiliation(s)
- Marcel P Stoop
- Department of Neurology, Erasmus University Medical Centre, Rotterdam, The Netherlands
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Bermúdez-Silva FJ, Pérez J, Cifuentes M, Pérez-Martín M, Grondona JM, López-Avalos MD, Estivill-Torrús G, Fernández-Llebrez P. A sensitive method to analyse the effect of putative regulatory ligands on the release of glycoprotein from primary cultures of dispersed bovine subcommissural organ cells. J Neurosci Methods 2010; 191:239-43. [PMID: 20619293 DOI: 10.1016/j.jneumeth.2010.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 06/14/2010] [Accepted: 07/01/2010] [Indexed: 11/29/2022]
Abstract
The subcommissural organ (SCO) releases into the cerebrospinal fluid (CSF) large glycoproteins that polymerize forming the Reissner's fibre (RF), which is involved in CSF circulation and homeostasis. We obtained high purity primary cultures of bovine secretory SCO cells and measured glycoprotein release by a reliable and sensitive ELISA method. We also analysed the effect of regulatory ligands known to control the secretory activity of the SCO. Cells cultured for short time (4h) released a high amount of glycoproteins that decreased with time. In young cultures, ATP increased and serotonin inhibited secretion rate. By contrast the acetylcholine agonist carbachol and high potassium did not evoke any detectable change in SCO glycoprotein release. These results support not only the suitability of the methodological approach but an important role of both ATP and serotonin in regulating SCO secretory activity as well.
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Affiliation(s)
- F J Bermúdez-Silva
- Laboratorio de Medicina Regenerativa, Fundación IMABIS, Avenida Carlos Haya 82, 29010 Málaga, Spain
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Rodríguez EM, Blázquez JL, Guerra M. The design of barriers in the hypothalamus allows the median eminence and the arcuate nucleus to enjoy private milieus: the former opens to the portal blood and the latter to the cerebrospinal fluid. Peptides 2010; 31:757-76. [PMID: 20093161 DOI: 10.1016/j.peptides.2010.01.003] [Citation(s) in RCA: 202] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 01/09/2010] [Accepted: 01/10/2010] [Indexed: 11/20/2022]
Abstract
The blood-brain barrier (BBB) is a single uninterrupted barrier that in the brain capillaries is located at the endothelial cells and in the circumventricular organs, such as the choroid plexuses (CP) and median eminence (ME), is displaced to specialized ependymal cells. How do hypothalamic hormones reach the portal circulation without making the BBB leaky? The ME milieu is open to the portal vessels, while it is closed to the cerebrospinal fluid (CSF) and to the arcuate nucleus. The cell body and most of the axons of neurons projecting to the ME are localized in areas protected by the BBB, while the axon terminals are localized in the BBB-free area of the ME. This design implies a complex organization of the intercellular space of the median basal hypothalamus. The privacy of the ME milieu implies that those neurons projecting to this area would not be under the influence of compounds leaking from the portal capillaries, unless receptors for such compounds are located at the axon terminal. Amazingly, the arcuate nucleus also has its private milieu that is closed to all adjacent neural structures and open to the infundibular recess. The absence of multiciliated cells in this recess should result in a slow CSF flow at this level. This whole arrangement should facilitate the arrival of CSF signal to the arcuate nucleus. This review will show how peripheral hormones can reach hypothalamic targets without making the BBB leaky.
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Affiliation(s)
- Esteban M Rodríguez
- Facultad de Medicina, Instituto de Anatomía, Histología y Patología, Universidad Austral de Chile, Valdivia, Chile.
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Veening JG, Barendregt HP. The regulation of brain states by neuroactive substances distributed via the cerebrospinal fluid; a review. Cerebrospinal Fluid Res 2010; 7:1. [PMID: 20157443 PMCID: PMC2821375 DOI: 10.1186/1743-8454-7-1] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 01/06/2010] [Indexed: 01/04/2023] Open
Abstract
The cerebrospinal fluid (CSF) system provides nutrients to and removes waste products from the brain. Recent findings suggest, however, that in addition, the CSF contains message molecules in the form of actively released neuroactive substances. The concentrations of these vary between locations, suggesting they are important for the changes in brain activity that underlie different brain states, and induce different sensory input and behavioral output relationships.The cranial CSF displays a rapid caudally-directed ventricular flow followed by a slower rostrally-directed subarachnoid flow (mainly towards the cribriform plate and from there into the nasal lymphatics). Thus, many brain areas are exposed to and can be influenced by substances contained in the CSF. In this review we discuss the production and flow of the CSF, including the mechanisms involved in the regulation of its composition. In addition, the available evidence for the release of neuropeptides and other neuroactive substances into the CSF is reviewed, with particular attention to the selective effects of these on distant downstream receptive brain areas. As a conclusion we suggest that (1) the flowing CSF is involved in more than just nutrient and waste control, but is also used as a broadcasting system consisting of coordinated messages to a variety of nearby and distant brain areas; (2) this special form of volume transmission underlies changes in behavioral states.
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Affiliation(s)
- Jan G Veening
- Department of Anatomy, (109) UMC St Radboud, Nijmegen, the Netherlands.
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A monoclonal antibody as a tool to study the subcommissural organ and Reissner's fibre of the sea lamprey: An immunofluorescence study before and after a spinal cord transection. Neurosci Lett 2009; 464:34-8. [DOI: 10.1016/j.neulet.2009.08.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 08/04/2009] [Accepted: 08/05/2009] [Indexed: 11/18/2022]
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22
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Schöniger S, Caprile T, Yulis CR, Zhang Q, Rodríguez EM, Nürnberger F. Physiological response of bovine subcommissural organ to endothelin 1 and bradykinin. Cell Tissue Res 2009; 336:477-88. [PMID: 19387687 DOI: 10.1007/s00441-009-0792-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 03/10/2009] [Indexed: 10/20/2022]
Abstract
The circumventricular organs (CVOs) regulate certain vegetative functions. Receptors for bradykinin (BDK) and endothelin (ET) have been found in some CVOs. The subcommissural organ (SCO) is a CVO expressing BDK-B2 receptors and secreting Reissner's fiber (RF) glycoproteins into the cerebrospinal fluid. This investigation was designed to search for ET receptors in the bovine SCO and, if found, to study the functional properties of this ET receptor and the BDK-B2 receptor. Cryostat sections exposed to (125)I ET1 showed dense labeling of secretory SCO cells, whereas the adjacent ciliated ependyma was devoid of radiolabel. The binding of (125)I ET1 was abolished by antagonists of ETA and ETB receptors. The intracellular calcium concentration ([Ca(2+)](i)) was measured in individual SCO cells prior to and after exposure to ET1, BDK, or RF glycoproteins. ET1 (100 nM) or BDK (100 nM) caused an increase in [Ca(2+)](i) in 48% or 53% of the analyzed SCO-cells, respectively. RF glycoproteins had no effect on [Ca(2+)](i) in SCO cells. ET and BDK evoked two types of calcium responses: prolonged and short responses. Prolonged responses included those with a constant slow decline of [Ca(2+)](i), biphasic responses, and responses with a plateau phase at the peak level of [Ca(2+)](i). ET1-treated SCO explants contained a reduced amount of intracytoplasmic AFRU (antiserum to RF glycoproteins)-immunoreactive material compared with sham-treated control explants. Our data suggest that ET1 and BDK regulate [Ca(2+)](i) in bovine SCO cells, and that the changes in [Ca(2+)](i) influence the secretory activity of these cells.
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Affiliation(s)
- S Schöniger
- Dr Senckenbergische Anatomie, FB Medizin der J.W.-Goethe-Universität, Theodor-Stern Kai 7, 60590, Frankfurt, Germany
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Vio K, Rodríguez S, Yulis CR, Oliver C, Rodríguez EM. The subcommissural organ of the rat secretes Reissner's fiber glycoproteins and CSF-soluble proteins reaching the internal and external CSF compartments. Cerebrospinal Fluid Res 2008; 5:3. [PMID: 18218138 PMCID: PMC2265671 DOI: 10.1186/1743-8454-5-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Accepted: 01/24/2008] [Indexed: 11/10/2022] Open
Abstract
Background The subcommissural organ (SCO) is a highly conserved brain gland present throughout the vertebrate phylum; it secretes glycoproteins into the cerebrospinal fluid (CSF), where they aggregate to form Reissner's fiber (RF). SCO-spondin is the major constituent protein of RF. Evidence exists that the SCO also secretes proteins that remain soluble in the CSF. The aims of the present investigation were: (i) to identify and partially characterize the SCO-secretory compounds present in the SCO gland itself and in the RF of the Sprague-Dawley rat and non-hydrocephalic hyh mouse, and in the CSF of rat; (ii) to make a comparative analysis of the proteins present in these three compartments; (iii) to identify the proteins secreted by the SCO into the CSF at different developmental periods. Methods The proteins of the SCO secreted into the CSF were studied (i) by injecting specific antibodies into ventricular CSF in vivo; (ii) by immunoblots of SCO, RF and CSF samples, using specific antibodies against the SCO secretory proteins (AFRU and anti-P15). In addition, the glycosylated nature of SCO-compounds was analysed by concanavalin A and wheat germ agglutinin binding. To analyse RF-glycoproteins, RF was extracted from the central canal of juvenile rats and mice; to investigate the CSF-soluble proteins secreted by the SCO, CSF samples were collected from the cisterna magna of rats at different stages of development (from E18 to PN30). Results Five glycoproteins were identified in the rat SCO with apparent molecular weights of 630, 450, 390, 320 and 200 kDa. With the exception of the 200-kDa compound, all other compounds present in the rat SCO were also present in the mouse SCO. The 630 and 390 kDa compounds of the rat SCO have affinity for concanavalin A but not for wheat germ agglutinin, suggesting that they correspond to precursor forms. Four of the AFRU-immunoreactive compounds present in the SCO (630, 450, 390, 320 kDa) were absent from the RF and CSF. These may be precursor and/or partially processed forms. Two other compounds (200, 63 kDa) were present in SCO, RF and CSF and may be processed forms. The presence of these proteins in both, RF and CSF suggests a steady-state RF/CSF equilibrium for these compounds. Eight AFRU-immunoreactive bands were consistently found in CSF samples from rats at E18, E20 and PN1. Only four of these compounds were detected in the cisternal CSF of PN30 rats. The 200 kDa compound appears to be a key compound in rats since it was consistently found in all samples of SCO, RF and embryonic and juvenile CSF. Conclusion It is concluded that (i) during the late embryonic life, the rat SCO secretes compounds that remain soluble in the CSF and reach the subarachnoid space; (ii) during postnatal life, there is a reduction in the number and concentration of CSF-soluble proteins secreted by the SCO. The molecular structure and functional significance of these proteins remain to be elucidated. The possibility they are involved in brain development has been discussed.
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Affiliation(s)
- Karin Vio
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile.
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Hoyo-Becerra C, López-Avalos MD, Pérez J, Miranda E, Rojas-Ríos P, Fernández-Llebrez P, Grondona JM. Continuous delivery of a monoclonal antibody against Reissner's fiber into CSF reveals CSF-soluble material immunorelated to the subcommissural organ in early chick embryos. Cell Tissue Res 2006; 326:771-86. [PMID: 16788834 DOI: 10.1007/s00441-006-0231-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Accepted: 04/24/2006] [Indexed: 10/24/2022]
Abstract
The subcommissural organ (SCO) is an ependymal differentiation located in the dorsal midline of the caudal diencephalon under the posterior commissure. SCO cells synthesize and release glycoproteins into the cerebrospinal fluid (CSF) forming a threadlike structure known as Reissner's fiber (RF), which runs caudally along the ventricular cavities and the central canal of the spinal cord. Numerous monoclonal antibodies have been raised against bovine RF and the secretory material of the SCO. For this study, we selected the 4F7 monoclonal antibody based on its cross-reactivity with chick embryo SCO glycoproteins in vivo. E4 chick embryos were injected with 4F7 hybridoma cells or with the purified monoclonal antibody into the ventricular cavity of the optic tectum. The hybridoma cells survived, synthesized and released antibody into the CSF for at least 13 days after the injection. E5 embryos injected with 4F7 antibody displayed precipitates in the CSF comprising both the monoclonal antibody and anti-RF-positive material. Such aggregates were never observed in control embryos injected with other monoclonal antibodies used as controls. Western blot analysis of CSF from E4-E6 embryos revealed several immunoreactive bands to anti-RF (AFRU) antibody. We also found AFRU-positive material bound to the apical surface of the choroid plexus primordia in E5 embryos. These and other ultrastructural evidence suggest the existence of soluble SCO-related molecules in the CSF of early chick embryos.
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Affiliation(s)
- C Hoyo-Becerra
- Departamento de Biología Celular, Genética y Fisiología, Campus de Teatinos, Universidad de Málaga, Málaga, Spain
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Richter HG, Tomé MM, Yulis CR, Vío KJ, Jiménez AJ, Pérez-Fígares JM, Rodríguez EM. Transcription of SCO-spondin in the subcommissural organ: evidence for down-regulation mediated by serotonin. ACTA ACUST UNITED AC 2005; 129:151-62. [PMID: 15469891 DOI: 10.1016/j.molbrainres.2004.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2004] [Indexed: 11/20/2022]
Abstract
The subcommissural organ (SCO) is a brain gland located in the roof of the third ventricle that releases glycoproteins into the cerebrospinal fluid, where they form a structure known as Reissner's fiber (RF). On the basis of SCO-spondin sequence (the major RF glycoprotein) and experimental findings, the SCO has been implicated in central nervous system development; however, its function(s) after birth remain unclear. There is evidence suggesting that SCO activity in adult animals may be regulated by serotonin (5HT). The use of an anti-5HT serum showed that the bovine SCO is heterogeneously innervated with most part being poorly innervated, whereas the rat SCO is richly innervated throughout. Antibodies against serotonin receptor subtype 2A rendered a strong immunoreaction at the ventricular cell pole of the bovine SCO cells and revealed the expected polypeptides in blots of fresh and organ-cultured bovine SCO. Analyses of organ-cultured bovine SCO treated with 5HT revealed a twofold decrease of both SCO-spondin mRNA level and immunoreactive RF glycoproteins, whereas no effect on release of RF glycoproteins into the culture medium was detected. Rats subjected to pharmacological depletion of 5HT exhibited an SCO-spondin mRNA level twofold higher than untreated rats. These results indicate that 5HT down-regulates SCO-spondin biosynthesis but apparently not its release, and suggest that 5HT may exert the effect on the SCO via the cerebrospinal fluid.
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Affiliation(s)
- Hans G Richter
- Instituto de Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile.
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Corpa JM, Peris B, Ribes V, Palacio J, Liste F. Hydrocephalus in a newborn bottlenosed dolphin (Tursiops truncatus). Vet Rec 2005; 155:208-10. [PMID: 15368759 DOI: 10.1136/vr.155.7.208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- J M Corpa
- Departamento Atención Sanitarià, Salud Pública y Sanidad Animal Histología y Anatomia Patológica, Spain
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Fernández-Llebrez P, Grondona JM, Pérez J, López-Aranda MF, Estivill-Torrús G, Llebrez-Zayas PF, Soriano E, Ramos C, Lallemand Y, Bach A, Robert B. Msx1-Deficient Mice Fail to Form Prosomere 1 Derivatives, Subcommissural Organ, and Posterior Commissure and Develop Hydrocephalus. J Neuropathol Exp Neurol 2004; 63:574-86. [PMID: 15217086 DOI: 10.1093/jnen/63.6.574] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Msx1 is a regulatory gene involved in epithelio-mesenchymal interactions in limb formation and organogenesis. In the embryonic CNS, the Msx1 gene is expressed along the dorsal midline. Msx1 mutant mice have been obtained by insertion of the nlacZ gene in the Msx1 homeodomain. The most important features of homozygous mutants that we observed were the absence or malformation of the posterior commissure (PC) and of the subcommissural organ (SCO), the collapse of the cerebral aqueduct, and the development of hydrocephalus. Heterozygous mutants developed abnormal PC and reduced SCO, as revealed by specific antibodies against SCO secretory glycoproteins. About one third of the heterozygous mutants also showed hydrocephalus. Other defects displayed by homozygous mutants were ependymal denudation, subventricular cavitations and edema, and underdevelopment of the pineal gland and subfornical organ. Some homozygous mutants developed both SCO and PC, probably as a consequence of genetic redundancy with Msx2. However, these mutants did not show SCO-immunoreactive glycoproteins and displayed obstructive hydrocephalus. This suggests that Msx1 is necessary for the synthesis of SCO glycoproteins, which would then be required for the maintenance of an open aqueduct.
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Affiliation(s)
- P Fernández-Llebrez
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.
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Bermúdez-Silva FJ, León-Quinto T, Martín F, Soria B, Nadal A, Pérez J, Fernández-Llebrez P. Bovine subcommissural organ displays spontaneous and synchronous intracellular calcium oscillations. Brain Res 2003; 977:90-6. [PMID: 12788517 DOI: 10.1016/s0006-8993(03)02764-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The subcommissural organ (SCO) is an ependymal brain gland that secretes into the cerebrospinal fluid glycoproteins that polymerize, forming Reissner's fiber (RF). The SCO-RF complex seems to be involved in vertebrate nervous system development, although its role in adults is unknown. Furthermore, its physiology is still greatly undetermined, and little is known about the release control of SCO secretion and the underlying intracellular mechanisms. In this report, we show that up to 90% of 3-5-day-old in vitro SCO cells from both intact and partially-dispersed SCO explants displayed spontaneous cytosolic Ca2+ oscillations. The putative role of these spontaneous calcium oscillations in SCO secretory activity is discussed taking into consideration several previous findings. Two distinct subpopulations of SCO cells were detected, each one containing cells with synchronized calcium oscillations. A possible existence of different functional domains in SCO is therefore discussed. Oscillations persisted in the absence of extracellular Ca2+, indicating the major involvement of Ca2+ released from internal stores. Depolarization failed to induce intracellular calcium increases, although it disturbed the oscillation frequency, suggesting a putative modulator role of depolarizing agonists on the calcium oscillating pattern through voltage-gated calcium channels. Carbachol, a cholinergic agonist, evoked a switch in Ca2+ signaling from a calcium oscillating mode to a sustained and increased intracellular Ca2+ mode in 30% of measured cells, suggesting the involvement of acetylcholine in SCO activity, via a calcium-mediated response.
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Affiliation(s)
- F Javier Bermúdez-Silva
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, 29071 Málaga, Spain
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Caprile T, Hein S, Rodríguez S, Montecinos H, Rodríguez E. Reissner fiber binds and transports away monoamines present in the cerebrospinal fluid. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2003; 110:177-92. [PMID: 12591155 DOI: 10.1016/s0169-328x(02)00565-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The subcommissural organ (SCO) is a brain gland that secretes glycoproteins into the cerebrospinal fluid (CSF), where they subsequently aggregate to form Reissner fiber (RF). By addition of newly released glycoproteins to its cephalic end, RF grows constantly through the Sylvian aqueduct, fourth ventricle and central canal of the spinal cord. Disaggregation of RF-material and passage to blood occur when RF reaches the terminal ventricle at the filum. The present investigation was designed to test the hypothesis that RF binds, transports and clears away monoamines present in the CSF. Four experimental protocols were applied: (i) in vivo binding of labeled monoamines to the rat RF, studied by pulse and chase, and after perfusion for 7 days; (ii) identification of monoamines, by high-performance liquid chromatography (HPLC), naturally occurring in the bovine RF; (iii) in vitro binding of labeled and unlabeled monoamines to the isolated bovine RF; and (iv) tentative identification of the amine binding site(s) in RF-proteins by use of specific antibodies. The results obtained indicate that RF participates in the regulation of the CSF concentration of monoamines either by binding and transporting them away throughout the central canal of the spinal cord (L-DOPA, noradrenaline, adrenaline), or by transiently binding them and releasing them back to the CSF (serotonin). Furthermore, evidence was obtained that (i) adrenaline and noradrenaline share the same binding site, and that this site would correspond to a repeated sequence present in the SCO-spondin, the major protein component of RF; and (ii) serotonin has its own binding site in RF.
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Affiliation(s)
- Teresa Caprile
- Instituto de Histología Y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
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Chatelin S, Wehrlé R, Mercier P, Morello D, Sotelo C, Weber MJ. Neuronal promoter of human aromatic L-amino acid decarboxylase gene directs transgene expression to the adult floor plate and aminergic nuclei induced by the isthmus. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2001; 97:149-60. [PMID: 11750071 DOI: 10.1016/s0169-328x(01)00318-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In order to analyze the regulatory sequences involved in the neuronal expression of aromatic L-amino acid decarboxylase (AADC), we have generated transgenic mice carrying the LacZ gene under the control of a 3.6-kb human aadc genomic fragment flanking the neuronal alternative first exon. A series of double labeling experiments were performed to compare the pattern of transgene expression to that of specific markers for catecholaminergic and serotonergic neurons. In the adult brain parenchyma, transgene expression was observed in the substantia nigra (SN), the ventral tegmental area (VTA) and the dorsal, medial and pontine raphe nuclei. A large degree of co-expression was observed with tyrosine-hydroxylase (TH) in the SN and VTA, and with serotonin (5-HT) in the dorsal raphe nucleus. Moreover, expression was observed in cells that were both TH- and 5-HT-negative, in particular in the ventral tegmental decussation and the dorsal tip of the VTA. Transgene expression was also observed in the walls of central cavities. Cells positive for both beta-gal and PSA-NCAM were localized in the ventral ependyma of the third and fourth ventricle, and of the central canal of the spinal cord, in what appears to be the adult floor plate. Transgene expressing, PSA-NCAM negative, cells located along the ventral midline of the spinal cord seemed to have migrated out of the ependyma. Our data thus reveal the complexity of aadc gene regulation. The present transgene provides a unique marker for monoaminergic nuclei induced by the isthmus and for the adult floor plate.
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Affiliation(s)
- S Chatelin
- Laboratoire de Biologie Moléculaire Eucaryote, UMR5099, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex, France
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31
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Schöniger S, Wehming S, Gonzalez C, Schöbitz K, Rodríguez E, Oksche A, Yulis CR, Nürnberger F. The dispersed cell culture as model for functional studies of the subcommissural organ: preparation and characterization of the culture system. J Neurosci Methods 2001; 107:47-61. [PMID: 11389941 DOI: 10.1016/s0165-0270(01)00351-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The subcommissural organ (SCO) is an enigmatic secretory gland of the brain, which is believed to be derived from ependymal (glial) precursor cells. We here developed a dispersed cell culture system of the bovine SCO as an approach to functional analyses of this brain gland. Tissue of the bovine SCO obtained from the slaughterhouse was papain dissociated either directly after dissection or after preparation of SCO explants. The latter had been maintained for 4-6 weeks in organ culture. The dispersed cells were cultured for up to 14 days and continuously tested for their secretory state by immunostaining of their secretory product. With respect to the morphology of the SCO cells (shape, processes, nucleus), no difference was found between the culture of freshly dissociated SCOs and that of dissociated SCO explants. In all cases, the dissociation caused a dedifferentiation; typical elongated cells were formed increasingly after 1 day of culture. Thereafter, only the cellular size increased, whereas the shape and the viability of the cells remained unchanged. Proliferating SCO cells were never observed. The culture obtained from fresh SCO tissue contained more glia cells and fibrocytes than the culture prepared from SCO explants. The proliferation of glia cells and fibrocytes was suppressed by blocking the mitotic activity with cytosine-beta-D-arabino furanoside (CAF). The cytophysiological features of the cultured dispersed cells of both origins did not differ as demonstrated by classical histology, by immunocytochemistry for the secretory products of the SCO, by the characteristics of calcium influx into the cytoplasm ([Ca2+]i) and cyclic adenosine monophosphate (cAMP) after stimulation with adenosine-5-triphosphate, substance P or serotonin, and by the activation of the transcription factor cAMP-responsive element-binding protein. Because of the maintenance of their viability, their capacity to release the secretory product into the culture medium, their receptive capacity, and their signal transduction pathways, we conclude that the dispersed cell culture system, especially that obtained from SCO explants, represents an appropriate and useful model for functional studies of the mammalian SCO.
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Affiliation(s)
- S Schöniger
- Dr Senckenbergische Anatomie Institut für Anatomie II, Klinikum der J.W. Goethe-Universität, Theodor-Stern-Kai 7, D-60590, Frankfurt, Germany
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Rodríguez S, Caprile T. Functional aspects of the subcommissural organ-Reissner's fiber complex with emphasis in the clearance of brain monoamines. Microsc Res Tech 2001; 52:564-72. [PMID: 11241866 DOI: 10.1002/1097-0029(20010301)52:5<564::aid-jemt1041>3.0.co;2-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Reissner's fiber (RF) extends along the cerebral aqueduct, fourth ventricle, and the entire length of the central canal of the spinal cord. It grows continuously in the caudal direction by addition of newly released glycoproteins by the subcommissural organ (SCO) to its proximal end. Several hypotheses about RF function have been advanced. One of them postulates that RF binds biogenic amines present in the CSF and clears them away. In recent years, this hypothesis has been tested in our laboratory by using several experimental protocols. Firstly, the CSF concentration of monoamines was investigated in RF-deprived rats subjected to immunological neutralization of the SCO-RF complex. Secondly, the capacity of RF to bind monoamines in vivo was studied by injecting radiolabeled serotonin or noradrenaline into the rat CSF, and by perfusing them into the CSF, during one week, using an Alzet's osmotic pump. In vitro binding studies were performed using isolated bovine RF. All the findings obtained indicate that RF binds monoamines present in the ventricular CSF and then transports them along the central canal. In the absence of RF, the CSF concentration of monoamines increases sharply.
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Affiliation(s)
- S Rodríguez
- Instituto de Histología y Patología, Universidad Austral de Chile, Casilla 567 Valdivia, Chile. srodrig2@.uach.cl
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Miranda E, Almonacid JA, Rodriguez S, Perez J, Hein S, Cifuentes M, Fernández-Llebrez P, Rodríguez EM. Searching for specific binding sites of the secretory glycoproteins of the subcommissural organ. Microsc Res Tech 2001; 52:541-51. [PMID: 11241864 DOI: 10.1002/1097-0029(20010301)52:5<541::aid-jemt1039>3.0.co;2-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The molecular organization of Reissner's fiber (RF), the structure of its proteins, and the permanent turnover of these proteins are all facts supporting the possibility that RF may perform multiple functions. There is evidence that CSF-soluble RF-glycoproteins may occur under physiological conditions. The present investigation was designed to investigate the probable existence within the CNS of specific binding sites for RF-glycoproteins. Three experimental protocols were used: (1) immunocytochemistry of the CNS of bovine fetuses using anti-idiotypic antibodies, raised against monoclonal antibodies developed against bovine RF-glycoproteins; (2) in vivo binding of the RF glycoproteins, perfusing into the rat CSF 125I-labeled RF-glycoproteins, or grafting SCO into a lateral ventricle of the rat; (3) in vitro binding of unlabeled RF-glycoproteins to rat and bovine choroid plexuses maintained in culture. One of the anti-idiotypic antibody generated by a Mab raised against RF-glycoproteins binds to choroidal cells. Furthermore, binding of RF-glycoproteins to the rat choroid plexus was obtained when: (1) the choroid plexus was cultured in the presence of unlabeled RF-glycoproteins; (2) the concentration of soluble RF-glycoproteins in the CSF was increased by isografting SCOs into a lateral ventricle; (3) radiolabeled glycoproteins were perfused into the ventricular CSF. This evidence suggests that the apical plasma membrane of the ependymal cells of the choroid plexus has specific binding sites for RF-glycoproteins, of unknown functional significance. The radiolabeled RF-glycoproteins perfused into the rat CSF also bound to the paraventricular thalamic nucleus, the floor of the Sylvian aqueduct and of the rostral half of the fourth ventricle, and the meninges of the brain and spinal cord. The labeling of the paraventricular thalamic nucleus points to a functional relationship between this nucleus and the SCO. The possibility that the SCO may be a component of the circadian timing system is discussed.
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Affiliation(s)
- E Miranda
- Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
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Abstract
Under normal physiological conditions the cerebrospinal fluid (CSF) is secreted continuously, although this secretion undergoes circadian variations. Mechanisms operating at the vascular side of the choroidal cells involve a sympathetic and a cholinergic innervation, with the former inhibiting and the latter stimulating CSF secretion. There are also regulatory mechanisms operating at the ventricular side of the choroidal cells, where receptors for monoamines such as dopamine, serotonin, and melatonin, and for neuropeptides such as vasopressin, atrial natriuretic hormone, and angiotensin II, have been identified. These compounds, that are normally present in the CSF, participate in the regulation of CSF secretion. Although the mechanisms responsible for the CSF circulation are not fully understood, several factors are known to play a role. There is evidence that the subcommissural organ (SCO)--Reissner's fiber (RF) complex is one of the factors involved in the CSF circulation. In mammals, the predominant route of escape of CSF into blood is through the arachnoid villi. In lower vertebrates, the dilatation of the distal end of the central canal, known as terminal ventricle or ampulla caudalis, represents the main site of CSF escape into blood. Both the function and the ultrastructural arrangement of the ampulla caudalis suggest that it may be the ancestor structure of the mammalian arachnoid villi. RF-glycoproteins reaching the ampulla caudalis might play a role in the formation and maintenance of the route communicating the CSF and blood compartments. The SCO-RF complex may participate, under physiological conditions, in the circulation and reabsorption of CSF. Under pathological conditions, the SCO appears to be involved in the pathogeneses of congenital hydrocephalus. Changes in the SCO have been described in all species developing congenital hydrocephalus. In these reports, the important question whether the changes occurring in the SCO precede hydrocephalus, or are a consequence of the hydrocephalic state, has not been clarified. Recently, evidence has been obtained indicating that a primary defect of the SCO-RF complex may lead to hydrocephalus. Thus, a primary and selective immunoneutralization of the SCO-RF complex during the fetal and early postnatal life leads to absence of RF, aqueductal stenosis, increased CSF concentration of monoamines, and a moderate but sustained hydrocephalus.
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Affiliation(s)
- J M Pérez-Fígares
- Departamento de Biología Celular y Genética, Facultad de Ciencias, Universidad de Málaga, E-29071 Málaga, Spain.
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