Reactive astrocytes express bis, a bcl-2-binding protein, after transient forebrain ischemia.
Bis (also called Bag-3), identified as a novel Bcl-2-interacting protein, has been shown to enhance anti-cell death activity of Bcl-2. Because ischemia/reperfusion induces expression of Bcl-2, we examined the changes in the pattern of Bis expression in the adult rat hippocampus after transient forebrain ischemia. Western blot analysis with protein extracts from the hippocampus showed that, compared with controls, levels of Bis were markedly increased seven days after ischemia. An immunohistochemical study showed that the expression of Bis increased preferentially in the CA1 and the dentate hilar regions, and peaked at 3-7 days after reperfusion. The temporal and spatial patterns of expression for both Bis and glial fibrillary acidic protein (GFAP) were very similar, and double immunofluorescence histochemistry showed that Bis was expressed in reactive astrocytes, which express GFAP. Immunolabeling of adjacent sections with anti-Bcl-2 and anti-Hsp70 antibodies revealed that the pattern of Bis expression closely correlates with that of Bcl-2, but clearly differs from that of Hsp70. Coexpression of Bis and Bcl-2 in reactive astrocytes was confirmed by double immunofluorescence histochemistry. Our results demonstrate that reactive astrocytes transiently up-regulate Bis after ischemia/reperfusion in the adult rat hippocampus. However, the precise role of Bis in the astrocytic response to ischemia/reperfusion in relation to Bcl-2 remains to be determined.
Lee
Mun-Yong
MY
Department of Anatomy, The Catholic University of Korea, Seoul 137-701, Korea.
Kim
Seong Yun
SY
Shin
Soon-Lim
SL
Choi
Yun-Sik
YS
Lee
Jung-Hee
JH
Tsujimoto
Yoshihide
Y
Lee
Jeong-Hwa
JH
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D000906:Antibodies; D051017:Apoptosis Regulatory Proteins; D001253:Astrocytes / Q000737:chemistry / Q000378:metabolism*; D002352:Carrier Proteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis / Q000276:immunology; D006624:Hippocampus / Q000166:cytology; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D008297:Male; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation / Q000502:physiology
D048868:Adaptor Proteins, Signal Transducing; D000906:Antibodies; D051017:Apoptosis Regulatory Proteins; C498807:BAG3 protein, rat; D002352:Carrier Proteins; D018840:HSP70 Heat-Shock Proteins; D019253:Proto-Oncogene Proteins c-bcl-2