title: Chondroitin sulfate proteoglycan tenascin-R regulates glutamate uptake by adult brain astrocytes.
abstract: In our previous study, the CS-56 antibody, which recognizes a chondroitin sulfate moiety, labeled a subset of adult brain astrocytes, yielding a patchy extracellular matrix pattern. To explore the molecular nature of CS-56-labeled glycoproteins, we purified glycoproteins of the adult mouse cerebral cortex using a combination of anion-exchange, charge-transfer, and size-exclusion chromatographies. One of the purified proteins was identified as tenascin-R (TNR) by mass spectrometric analysis. When we compared TNR mRNA expression patterns with the distribution patterns of CS-56-positive cells, TNR mRNA was detected in CS-56-positive astrocytes. To examine the functions of TNR in astrocytes, we first confirmed that cultured astrocytes also expressed TNR protein. TNR knockdown by siRNA expression significantly reduced glutamate uptake in cultured astrocytes. Furthermore, expression of mRNA and protein of excitatory amino acid transporter 1 (GLAST), which is a major component of astrocytic glutamate transporters, was reduced by TNR knockdown. Our results suggest that TNR is expressed in a subset of astrocytes and contributes to glutamate homeostasis by regulating astrocytic GLAST expression.
authors: From the Departments of Anatomy and Neuroscience and.
authors: Hiroaki
authors: H
authors: Okuda
authors: Kouko
authors: K
authors: Tatsumi
authors: Shoko
authors: S
authors: Morita
authors: Yukinao
authors: Y
authors: Shibukawa
authors: Hiroaki
authors: H
authors: Korekane
authors: Noriko
authors: N
authors: Horii-Hayashi
authors: Yoshinao
authors: Y
authors: Wada
authors: Naoyuki
authors: N
authors: Taniguchi
authors: Akio
authors: A
authors: Wanaka
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000378:metabolism* / Q000648:ultrastructure; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology* / Q000378:metabolism; D002809:Chondroitin Sulfates / Q000378:metabolism; D027341:Excitatory Amino Acid Transporter 1 / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism; D006706:Homeostasis / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D019063:Tenascin / Q000235:genetics / Q000378:metabolism*
chemical_list: D027341:Excitatory Amino Acid Transporter 1; D006023:Glycoproteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C493393:Slc1a3 protein, mouse; D019063:Tenascin; C074638:tenascin R; D018698:Glutamic Acid; D002809:Chondroitin Sulfates
keywords: Astrocytes; Chondroitin Sulfate; Extracellular Matrix; Glutamate; Tenascin