title: Brain localization of leucine-rich α2-glycoprotein and its role.
abstract: OBJECTIVE
  We have previously reported that the level of leucine-rich alpha-2-glycoprotein (LRG) expression is specifically increased in cerebrospinal fluid (CSF) of idiopathic normal pressure hydrocephalus (INPH). The objective of this study is to examine the localization of LRG - the cerebral areas where it is expressed.
  
  
  METHODS
  The histological sections of autopsied brain specimens from ten subjects, five adult cases (mean age 43.6 years; range 34-50 years) and five senile cases (mean age 76.0 years; range 67-88 years) were prepared, multistained with antibodies against human LRG, glial fibrillary acidic protein (GFAP), CD31, and aquaporin-4 (AQP4), and reviewed for the expression sites of LRG.
  
  
  RESULTS
  Immunostains of GFAP and LRG were compared in standard brain specimens from elderly patients. The results indicated that LRG is distributed throughout the entire brain, with especially high expression in the deep cerebral cortex. In addition, the cells that express LRG showed similar morphology to astrocytes. Double staining of CD31 and LRG revealed a significant expression of LRG in the pericapillary regions. The expression was observed in resident astrocytes, as well as in the capillary vessel to which astrocytic processes grow and adhere. When age-related comparisons were made between senile and adult specimens, LRG expression increased with age.
  
  
  CONCLUSIONS
  LRG expression in resident astrocytes increased with age.
authors: Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan. madoka66@juntendo.ac.jp
authors: Madoka
authors: M
authors: Nakajima
authors: M
authors: M
authors: Miyajima
authors: I
authors: I
authors: Ogino
authors: M
authors: M
authors: Watanabe
authors: Y
authors: Y
authors: Hagiwara
authors: T
authors: T
authors: Segawa
authors: K
authors: K
authors: Kobayashi
authors: H
authors: H
authors: Arai
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D051401:Aquaporin 4 / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D051296:Glucose Transporter Type 5 / Q000378:metabolism; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism; D000076104:Oligodendrocyte Transcription Factor 2; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D051401:Aquaporin 4; D051792:Basic Helix-Loop-Helix Proteins; D005904:Glial Fibrillary Acidic Protein; D051296:Glucose Transporter Type 5; D006023:Glycoproteins; D009419:Nerve Tissue Proteins; D000076104:Oligodendrocyte Transcription Factor 2; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D012333:RNA, Messenger; C496030:AQP4 protein, human; C015246:LRG1 protein, human; C405708:OLIG2 protein, human; C495726:SLC2A5 protein, human