Transient expression of juvenile-type neurocan by reactive astrocytes in adult rat brains injured by kainate-induced seizures as well as surgical incision.
Neurocan is one of the major chondroitin sulfate proteoglycans expressed in nervous tissues. The expression of neurocan is developmentally regulated, and full-length neurocan is detected in juvenile brains but not in adult brains. In the present study, we demonstrated by western blot analysis that full-length neurocan transiently appeared in adult rat hippocampus when it was lesioned by kainate-induced seizures. Immunohistochemical studies showed that neurocan was detected mainly around the CA1 region although the seizure resulted in neuronal cell degeneration in both the CA1 and CA3 regions of the hippocampus. Double-labeling for neurocan mRNA and glial fibrillary acidic protein demonstrated that many reactive astrocytes expressed neurocan mRNA. The re-expression of full-length neurocan was also observed in the surgically injured adult rat brain. In contrast, the expression of other nervous tissue chondroitin sulfate proteoglycans, such as phosphacan and neuroglycan C, was not intensified but rather was either reduced in the kainate-lesioned hippocampus or in the surgically injured cerebral cortex. These observations indicate that induction of neurocan expression by reactive astrocytes is a common phenomenon in the repair process of adult brain injury, and therefore, it can be postulated that juvenile-type neurocan plays some roles in brain repair.
Matsui
F
F
Department of Perinatology, Institute for Developmental Research, Kasugai, Aichi 480-0392, Japan. fmatsui@inst-hsc.pref.aichi.jp
Kawashima
S
S
Shuo
T
T
Yamauchi
S
S
Tokita
Y
Y
Aono
S
S
Keino
H
H
Oohira
A
A
D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D015153:Blotting, Western; D001930:Brain Injuries / Q000378:metabolism*; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics / Q000378:metabolism*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D007150:Immunohistochemistry; D007608:Kainic Acid; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D058580:Neurocan; D011509:Proteoglycans / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism*; D053670:Syndecan-3; D013997:Time Factors
D011508:Chondroitin Sulfate Proteoglycans; C485738:Cspg5 protein, rat; D005904:Glial Fibrillary Acidic Protein; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D058580:Neurocan; D011509:Proteoglycans; D012333:RNA, Messenger; C508301:SDC3 protein, human; C508303:Sdc3 protein, rat; D053670:Syndecan-3; C076817:NCAN protein, human; C516895:PTPRZ1 protein, human; C516897:Ptprz1 protein, rat; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5; D007608:Kainic Acid