Proteomic analysis of the cerebrospinal fluid in multiple sclerosis and neuromyelitis optica patients

The present study aimed to compare the 2-dimensional (2D) electrophoresis pattern of the cerebrospinal fluid (CSF) in multiple sclerosis (MS), neuromyelitis optica (NMO) and control individuals, to identify the proteins with differential expression and to examine their significance. CSF samples from the three groups were collected and total protein was isolated and quantified using the Bradford method. 2D electrophoresis of the samples was conducted using equal amounts of CSF. In the CSF 2D gel electrophoresis map, 118 points were obtained from the MS group, 155 points from the NMO group and 350 points from the normal control group. Non-matching proteins appeared in 14 spots in the MS group and in 45 spots in the NMO group, and were also expressed in the 2D electrophoresis pattern of the normal control group. Four differential proteins were identified through the HD-MS/MS and MASCOT network search. Pre-albumin (PA) was found only in the CSF 2D gel electrophoresis map of the MS patients. Keratin 1 was expressed in the normal control group, but not in the MS group. The difference in the expression of keratin 9 in the MS group was twice that in the normal control group. The expression of keratin 1, keratin 9 and transferrin in the NMO group was twice that in the normal control group. The expression of PA was found only in the CSF 2D gel electrophoresis map of the MS patients, and not in the NMO group. Keratin 1 was expressed in the NMO group, but not in the MS group. The expression of a variety of proteins in the 2D electrophoresis pattern of CSF was significantly different in the MS, NMO and control groups. PA, keratin 1, transferrin and keratin 9 are identified as significantly differentially expressed proteins.