Immobilization stress induces the expression of alphaB-crystallin in rat hippocampus: implications of glial activation in stress-mediated hippocampal degeneration.
Overexpression and abnormal aggregation of a small heat shock protein, B-crystallin, in reactive astrocytes has been implicated in various neurodegenerative diseases and brain tumors. To investigate the potential involvement of glial activation in stress-induced hippocampal damage, we analyzed B-crystallin gene expression in the hippocampus of immobilized rats. Male Sprague-Dawley rats were subjected to single or repeated immobilization stress. Both single and repeated immobilization markedly increased the level of B-crystallin mRNA in the hippocampus. Repeated immobilization notably accumulated B-crystallin protein, with a substantial portion in the insoluble fraction. Treatment of primary cortical astrocytes with stress-related glucocorticoid resulted in considerable elevation of B-crystallin expression. The accumulation of B-crystallin may serve as one of the important pathogenic mechanisms involved in hippocampal degeneration associated with stress.
Yun
Su-Jin
SJ
Graduate School of East-West Medical Science, Kyung Hee University, 1 Seochun, Yong-In 449-701, South Korea.
Hahm
Dae-Hyun
DH
Lee
Eunjoo H
EH
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D003459:Crystallins / Q000235:genetics*; D003907:Dexamethasone / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D019636:Neurodegenerative Diseases / Q000378:metabolism* / Q000503:physiopathology; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012149:Restraint, Physical; D013312:Stress, Physiological / Q000378:metabolism* / Q000503:physiopathology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D003459:Crystallins; D018841:HSP90 Heat-Shock Proteins; D012333:RNA, Messenger; D003907:Dexamethasone