Osteopontin in kainic acid-induced microglial reactions in the rat brain.
The present study was performed to investigate the spatial and temporal expression of osteopontin (OPN) mRNA in the rat brain after kainic acid-induced seizures, and to determine whether this phenomenon is associated spatiotemporally with the microglial reaction. The expression of OPN mRNA was detected using an in situ hybridization technique and Northern blot analysis. Following intraperitoneal injection of kainic acid (10 mg/kg), OPN mRNA was expressed in selective vulnerable areas, including the hippocampus, thalamus, hypothalamus, amygdala, and entorhinal cortex. Comparison of the morphology and localization with the established microglial marker OX-42 in the adjacent sections positively identified the OPN-expressed cells as microglia. Furthermore, double labeling experiments revealed that OPN mRNA expression was confined to ameboid-like cells among microglia stained with GSI-B4, an another microglial marker. These findings from a rat model of seizure support the notion that OPN can be synthesized in a subpopulation of reactive microglial cells. It can therefore be assumed that in the response of the brain to excitotoxic injury, synthesis of OPN occurs generally in a subset of activated microglia.
Kim
Seong Yun
SY
Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul.
Choi
Yun-Sik
YS
Choi
Jeong-Sun
JS
Cha
Jung-Ho
JH
Kim
Ok Nyu
ON
Lee
Sang Bok
SB
Chung
Jin-Woong
JW
Chun
Myung-Hoon
MH
Lee
Mun-Yong
MY
D000818:Animals; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D030161:Avian Proteins; D051926:Basigin; D001798:Blood Proteins; D001921:Brain / Q000166:cytology / Q000378:metabolism; D017403:In Situ Hybridization; D007608:Kainic Acid / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis; D017628:Microglia / Q000187:drug effects* / Q000378:metabolism; D053495:Osteopontin; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism; D012795:Sialoglycoproteins / Q000096:biosynthesis / Q000235:genetics*; D014018:Tissue Distribution
D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D030161:Avian Proteins; D001798:Blood Proteins; C102624:Bsg protein, Gallus gallus; C079432:Bsg protein, rat; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D053495:Osteopontin; D051926:Basigin; D007608:Kainic Acid