Proteomic Analysis of Rat Cerebral Cortex in the Subacute to Long-Term Phases of Focal Cerebral Ischemia-Reperfusion Injury

Stroke is a leading
cause of mortality and disability, and ischemic
stroke accounts for more than 80% of the disease occurrence. Timely
reperfusion is essential in the treatment of ischemic stroke, but
it is known to cause ischemia-reperfusion (I/R) injury and the relevant
studies have mostly focused on the acute phase. Here we reported on
a global proteomic analysis to investigate the development of cerebral
I/R injury in the subacute and long-term phases. A rat model was used,
with 2 h-middle cerebral artery occlusion (MCAO) followed with 1,
7, and 14 days of reperfusion. The proteins of cerebral cortex were
analyzed by SDS-PAGE, whole-gel slicing, and quantitative LC-MS/MS.
Totally 5621 proteins were identified, among which 568, 755, and 492
proteins were detected to have significant dys-regulation in the model
groups with 1, 7, and 14 days of reperfusion, respectively, when compared
with the corresponding sham groups (n = 4, fold change
≥1.5 or ≤0.67 and p ≤ 0.05).
Bioinformatic analysis on the functions and reperfusion time-dependent
dys-regulation profiles of the proteins exhibited changes of structures
and biological processes in cytoskeleton, synaptic plasticity, energy
metabolism, inflammation, and lysosome from subacute to long-term
phases of cerebral I/R injury. Disruption of cytoskeleton and synaptic
structures, impairment of energy metabolism processes, and acute inflammation
responses were the most significant features in the subacute phase.
With the elongation of reperfusion time to the long-term phase, a
tendency of recovery was detected on cytoskeleton, while inflammation
pathways different from the subacute phase were activated. Also, lysosomal
structures and functions might be restored. This is the first work
reporting the proteome changes that occurred at different time points
from the subacute to long-term phases of cerebral I/R injury and we
expect it would provide useful information to improve the understanding
of the mechanisms involved in the development of cerebral I/R injury
and suggest candidates for treatment.