Morphological diversities of CD44 positive astrocytes in the cerebral cortex of normal subjects and patients with Alzheimer's disease.
The localization of CD44 was investigated immunohistochemically in postmortem human brain tissue of control subjects and patients with Alzheimer's disease. CD44 is a multifunctional cell surface glycoprotein that serves as a receptor for hyaluronic acid, collagen types I and VI, and mucosal vascular addressin. In gray matter, it was found to be associated with some astrocytes of both protoplasmic and fibrous morphology. These positively stained astrocytes were most frequently observed in association with blood vessels, and had morphologies that were highly comparable to those described with the Golgi technique. Double immunostaining for CD44 and glial fibrillary acidic protein (GFAP) revealed that a significant number of these astrocytes were positive for both antigens. However, GFAP staining was mostly confined to the cell somata and proximal processes, while CD44 staining extended to a rich and extensive array of processes. Occasional CD44 positive cells of spherical morphology with a few thin varicose processes were observed. Their processes formed thick terminations on blood vessels, suggesting that these cells are a special class of astrocyte. In Alzheimer's disease brain, the number of CD44 positive astrocytes increased dramatically. These data suggest that astrocytes have very extensive branching patterns, which are reflected by CD44 staining patterns. CD44 may be an important adhesion molecule for these astrocytic processes.
Akiyama
H
H
Tokyo Institute of Psychiatry, Japan.
Tooyama
I
I
Kawamata
T
T
Ikeda
K
K
McGeer
P L
PL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000473:pathology*; D001253:Astrocytes / Q000166:cytology / Q000473:pathology*; D001344:Autopsy; D002352:Carrier Proteins / Q000032:analysis*; D002540:Cerebral Cortex / Q000166:cytology / Q000201:enzymology*; D003181:Complement C4 / Q000032:analysis; D015935:Complement C4b; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D018960:Hyaluronan Receptors; D007150:Immunohistochemistry; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology / Q000648:ultrastructure; D009928:Organ Specificity; D010446:Peptide Fragments / Q000032:analysis; D011956:Receptors, Cell Surface / Q000032:analysis*; D016201:Receptors, Lymphocyte Homing / Q000032:analysis*; D012016:Reference Values; D014793:Visual Cortex / Q000473:pathology
D002352:Carrier Proteins; D003181:Complement C4; D005904:Glial Fibrillary Acidic Protein; D018960:Hyaluronan Receptors; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D016201:Receptors, Lymphocyte Homing; D015935:Complement C4b; C032261:complement C4d