title: HNK-1 epitope-carrying tenascin-C spliced variant regulates the proliferation of mouse embryonic neural stem cells.
abstract: Neural stem cells (NSCs) possess high proliferative potential and the capacity for self-renewal with retention of multipotency to differentiate into neuronal and glial cells. NSCs are the source for neurogenesis during central nervous system development from fetal and adult stages. Although the human natural killer-1 (HNK-1) carbohydrate epitope is expressed predominantly in the nervous system and involved in intercellular adhesion, cell migration, and synaptic plasticity, the expression patterns and functional roles of HNK-1-containing glycoconjugates in NSCs have not been fully recognized. We found that HNK-1 was expressed in embryonic mouse NSCs and that this expression was lost during the process of differentiation. Based on proteomics analysis, it was revealed that the HNK-1 epitopes were almost exclusively displayed on an extracellular matrix protein, tenascin-C (TNC), in the mouse embryonic NSCs. Furthermore, the HNK-1 epitope was found to be present only on the largest isoform of the TNC molecules. In addition, the expression of HNK-1 was dependent on expression of the largest TNC variant but not by enzymes involved in the biosynthesis of HNK-1. By knocking down HNK-1 sulfotransferase or TNC by small interfering RNA, we further demonstrated that HNK-1 on TNC was involved in the proliferation of NSCs via modulation of the expression level of the epidermal growth factor receptor. Our finding provides insights into the function of HNK-1 carbohydrate epitopes in NSCs to maintain stemness during neural development.
authors.affiliation: From the Institute of Molecular Medicine and Genetics and Institute of Neuroscience, Medical College of Georgia, Augusta, Georgia 30912.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Yagi
authors.forename: Makoto
authors.initials: M
authors.lastname: Yanagisawa
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Nakatani
authors.forename: Toshio
authors.initials: T
authors.lastname: Ariga
authors.forename: Koichi
authors.initials: K
authors.lastname: Kato
authors.forename: Robert K
authors.initials: RK
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018959:CD57 Antigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D000939:Epitopes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D058953:Neural Stem Cells / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012326:RNA Splicing; D016415:Sequence Alignment; D019063:Tenascin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D018959:CD57 Antigens; D000939:Epitopes; D019063:Tenascin