The objective of this study is to analyze the differential
protein expression profile in cerebral cortex of rats with middle
cerebral ischemia/reperfusion (MCAO/R), explore the brain damage mechanism of MCAO/R at
protein level, and provide experimental foundation for searching specific marker
proteins of MCAO/R. Rat model of MCAO/R was established by modified
suture-occluded method, and the model was evaluated by the results of brain
2,3,5-triphenyltetrazolium chloride (TTC) and
hematoxylin-
eosin (HE) staining. Cerebral cortex of rats from
sham-operated group (
Sham) and MCAO/R groups was used for FASP enzymatic hydrolysis, i-TRAQ quantitative labeling, and reverse-phase liquid chromatography purification and separation. Orbitrap Q Exactive mass spectrometry was used for qualitative and quantitative analyses of total differential
protein expression profiles. MCAO/R rats had obvious
cerebral infarction lesions, and the relative surface area of
cerebral infarction was significantly different compared with
sham rats, suggesting that MCAO/R rat model was successfully prepared. There were 199 significant difference
proteins (MCAO/R vs
Sham, p < 0.05, |fold change|> 1.2), including 104 up-regulated
proteins and 95 down-regulated
proteins. Gene ontology (GO) enrichment analysis showed that the up-regulated
proteins were mainly concentrated in the biological processes of positive regulation of NF-κB transcription and I-κB
kinase-NF-κB, etc. Down-regulated
proteins were mainly concentrated in long-term synaptic potentiation, cellular response to DNA damage stimulus, etc. KEGG pathway analysis showed that the pathway involved in differential
proteins includes oxidative phosphorylation, metabolic pathway, and Ras signaling pathway. Network analysis of differential
proteins showed that Alb, ndufb5, ndufs7,
ApoB, Cdc42, Ndufa3, Igf1r, P4hb, Mbp, Gc, Nme1, Akt2, and other
proteins may play an important role in regulating oxidative stress, apoptosis, and inflammatory response in MCAO/R. Quantitative proteomics based on i-TRAQ labeling reveals the effect of
inflammation and apoptosis in brain damage mechanism of MCAO/R. Besides, this research provide some experimental foundation for search and determination of potential therapeutic targets of MCAO/R.