title: Induction of mRNAs and proteins for Na/K ATPase alpha1 and beta1 subunits following hypoxia/reoxygenation in astrocytes.
abstract: Characteristics of the cellular response to oxygen deprivation and subsequent reoxygenation (hypoxia/reoxygenation) include redirection of energy metabolism, increased glucose utilization and expression of oxygen-regulated proteins. Inhibition of protein synthesis during early reoxygenation period prevented effective astrocyte adaptation to hypoxia/reoxygenation, resulting in eventual cell death. To elucidate the role of astrocytes in the central nervous system in response to hypoxia/reoxygenation, we analyzed the cDNA library derived from the cultured rat astrocytes subjected to 24 h of hypoxia followed by reoxygenation by differential display, and isolated a cDNA corresponding to Na/K ATPase alpha1 subunit. The expression of Na/K ATPase alpha1 subunit mRNA as well as beta1subunit mRNA was transiently increased after reoxygenation, whereas hypoxia itself did not induce any gene expression change. Na/K ATPase alpha1 subunit protein was transiently increased, whereas the protein expression for Na/K ATPase beta1 subunit showed sustained induction after reoxygenation. Overexpression of beta1 subunit in HEK 293 cells subjected to hypoxia/reoxygenation promoted survival of the cells. These findings suggest that Na/K ATPases may contribute to maintain the cellular environment of astrocytes subjected to hypoxia/reoxygenation.
authors.affiliation: Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Kasai
authors.forename: Toshihide
authors.initials: T
authors.lastname: Yamashita
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamaguchi
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Yoshiya
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kawakita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tanaka
authors.forename: Hisashi
authors.initials: H
authors.lastname: Sugimoto
authors.forename: Masaya
authors.initials: M
authors.lastname: Tohyama
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000201:enzymology*; D015687:Cell Hypoxia / Q000502:physiology; D002470:Cell Survival; D002478:Cells, Cultured; D015971:Gene Expression Regulation, Enzymologic; D010100:Oxygen / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics* / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D000254:Sodium-Potassium-Exchanging ATPase; D010100:Oxygen