Sugar chains of cerebrospinal fluid transferrin as a new biological marker of Alzheimer's disease.
OBJECTIVE
Alzheimer's disease (AD) is a well-known type of dementia. However, it remains difficult to identify AD in the early stage and to distinguish it from other dementing disorders. We examined glycoproteins in cerebrospinal fluid (CSF) as potential biological markers of AD.


METHODS
CSF samples were collected from AD, other dementia and nondemented patients. Glycoproteins in CSF were detected by lectin blotting using wheat germ agglutinin (WGA), and sugar chain analysis was performed by isoelectric focusing.


RESULTS
In Alzheimer's CSF, several glycoproteins had lower WGA-binding activities, one of which was sufficiently sensitive and specific to distinguish AD from nondemented controls and other dementias. Further analysis identified this glycosylated protein as transferrin, and altered sugar chain composition of transferrin isoforms was observed despite normal protein levels in CSF.


CONCLUSIONS
The decreased WGA-binding activity of transferrin in AD is probably due to altered glycosylation of transferrin molecules. Transferrin glycosylation is thus a potential biological marker for AD diagnosis, and changes in this glycosylation may play an important role in the pathophysiology of AD.
Taniguchi
Miyako
M
Department of Biological Regulation, School of Health Sciences, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan. miyako@med.tottori-u.ac.jp
Okayama
Yuka
Y
Hashimoto
Yuki
Y
Kitaura
Miki
M
Jimbo
Daiki
D
Wakutani
Yosuke
Y
Wada-Isoe
Kenji
K
Nakashima
Kenji
K
Akatsu
Hiroyasu
H
Furukawa
Katsutoshi
K
Arai
Hiroyuki
H
Urakami
Katsuya
K
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D015415:Biomarkers / Q000134:cerebrospinal fluid*; D005260:Female; D006031:Glycosylation; D006801:Humans; D007525:Isoelectric Focusing; D008297:Male; D010446:Peptide Fragments / Q000134:cerebrospinal fluid; D010766:Phosphorylation; D024801:Tauopathies / Q000134:cerebrospinal fluid / Q000175:diagnosis; D014168:Transferrin / Q000134:cerebrospinal fluid* / Q000302:isolation & purification; D014909:Wheat Germ Agglutinins; D016875:tau Proteins / Q000134:cerebrospinal fluid
D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; D014168:Transferrin; D014909:Wheat Germ Agglutinins; C075222:amyloid beta-protein (1-42); D016875:tau Proteins