Expression of adenomatous polyposis coli protein in reactive astrocytes in hippocampus of kainic acid-induced rat.
The adenomatous polyposis coli gene (APC) was initially identified through its link to colon cancer. It is associated with the regulation of cell cycle progression, survival, and differentiation of normal tissues. Recent studies have demonstrated that APC is also expressed in the adult brain at high levels. However, its role in glial cells under pathological progression remains unclear. In this study, we evaluated the expression of APC and its association with beta-catenin signaling pathway, following the induction of an excitotoxic lesion by kainic acid (KA) injection, which cause pyramidal cell degeneration. APC was predominantly present in oligodendrocytes in the normal brain, but was specifically associated with activated astrocytes in the KA-treated brain. Our quantitative analysis revealed that APC significantly increased from 1 day post lesion (PI), reached peak values at 3 days PI, and decreased thereafter. The phospho-GSK3beta levels also showed similar spatiotemporal patterns while beta-catenin expression was reduced at 1 and then increasingly returned to normal levels at 3, 7 days PI. For the first time, our data demonstrate the injury-induced astrocytic changes in the levels of APC, GSK3beta, and beta-catenin in vivo, which may actively be participate in cell adhesion and in the signaling pathway regulating cell survivals during brain insults.
Lee
Ha Na
HN
Department of Anatomy, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, South Korea.
Jeon
Gye Sun
GS
Kim
Dong Woon
DW
Cho
Ik-Hyun
IH
Cho
Sa Sun
SS
D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D015153:Blotting, Western; D018690:Excitatory Amino Acid Agonists; D017491:Genes, APC; D038362:Glycogen Synthase Kinase 3; D000071679:Glycogen Synthase Kinase 3 beta; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D007150:Immunohistochemistry; D007608:Kainic Acid / Q000633:toxicity*; D051381:Rats; D051176:beta Catenin / Q000378:metabolism
D018690:Excitatory Amino Acid Agonists; D051176:beta Catenin; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3; D007608:Kainic Acid