Identification of Novel Biomarkers of Brain Damage in Patients with Hemorrhagic Stroke by Integrating Bioinformatics and Mass Spectrometry-Based Proteomics

Hemorrhagic stroke (HS) is a significant
cause of mortality that
requires rapid diagnosis and prompt medical attention. A time-efficient
diagnostic test to assist in the early classification of patients
with stroke would be of great value. The aims here were to (a) select
“brain-specific” proteins using a bioinformatics approach,
(b) develop selected reaction monitoring (SRM) assays for candidate
proteins, and (c) quantify these proteins in cerebrospinal fluid (CSF).
“The Human Protein Atlas” and the “Peptide Atlas”
were used to select proteins specifically and abundantly expressed
in brain tissue, excluding high-abundance plasma proteins. Protein
extracts from brain tissue were used for SRM assay development of
proteins of interest. The levels of 68 “brain-specific”
proteins were measured by SRM in 36 age-matched patients, including
individuals with HS (n = 15), ischemic stroke (n = 11), and controls (n = 10). Additionally,
S100B was measured using an electrochemoluminometric immunoassay.
CSF levels of S100B and eight of the “brain-specific”
proteins (NSE, GFAP, α-Inx, MBP, MT3, NFM, β-Syn, and
γ-Syn) were increased in a subset of samples from HS patients,
especially in those individuals with intraventricular hemorrhage and
poor outcome. Seven of these proteins (S100B, NSE, GFAP, α-Inx,
MBP, NFM, and β-Syn) showed significant differences between
patients with and without brain hemorrhage. Novel biomarkers of brain
injury (α-Inx, NFM, and β-Syn) were identified in the
CSF of patients with HS. Investigating the role of these proteins
in blood with more sensitive methods is warranted.