Subgroup differences in 'brain-type' transferrin and α-synuclein in Parkinson's disease and multiple system atrophy

• Published in: Journal of biochemistry (Tokyo) 2016-08, Vol.160 (2), p.87-91
• Main Authors: Yoshihara, Akioh, Fukatsu, Masahiko, Hoshi, Kyoka, Ito, Hiromi, Nollet, Kenneth, Yamaguchi, Yoshiki, Ishii, Ryotaro, Tokuda, Takahiko, Miyajima, Masakazu, Arai, Hajime, Kato, Takeo, Furukawa, Katsutoshi, Arai, Hiroyuki, Kikuchi, Akio, Takeda, Atsushi, Ugawa, Yoshikazu, Hashimoto, Yasuhiro
• Format: Article
• Language: English
• Subjects: alpha-Synuclein - blood; alpha-Synuclein - cerebrospinal fluid; Alzheimer Disease - blood; Alzheimer Disease - cerebrospinal fluid; Female; Humans; Male; Parkinson Disease - blood; Parkinson Disease - cerebrospinal fluid; Protein Isoforms - blood; Protein Isoforms - cerebrospinal fluid; Transferrin - cerebrospinal fluid
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/jb/mvw015

Two transferrin (Tf) glycan-isoforms were previously found in cerebrospinal fluid (CSF); one appears to be derived from serum (Tf-2) and the other from choroid plexus, a CSF-producing tissue (Tf-1). To analyse metabolic differences associated with the two isoforms, their ratio (Tf-2/Tf-1) was defined as the Tf index. Here we report that Tf indices of patients with tauopathies including Alzheimer's disease (2.29 + 0.64) were similar to those of neurological controls (2.07 + 0.87) (P = 0.147). In contrast, Tf indices with Parkinson's disease (PD, 3.38 ± 1.87) and multiple system atrophy (MSA, 3.15 ± 1.72) were higher than those of the controls (2.07 ± 0.87), the P-values being < 0.001 and 0.024, respectively. Tf indices of PD and MSA did not appear to be normally distributed. Indeed, detrended normal Quantile-Quantile plot analysis revealed the presence of an independent subgroup showing higher Tf indices in PD and MSA. The subgroup of PD showed higher levels of CSF α-synuclein (38.3 ± 17.8 ng/ml) than the rest (25.3 ± 11.3 ng/ml, P = 0.012). These results suggest that PD (and MSA) includes two subgroups, which show different metabolism of CSF transferrin and α-synuclein.