Cerebral ischemia entails rapid tissue damage in the affected brain area causing devastating neurological dysfunction. How each component of the neurovascular unit contributes or responds to the ischemic insult in the context of the human brain has not been solved yet. Thus, the analysis of the
proteome is a straightforward approach to unraveling these cell proteotypes. In this study, post-mortem brain slices from
ischemic stroke patients were obtained corresponding to infarcted (IC) and contralateral (CL) areas. By means of
laser microdissection, neurons and blood brain barrier structures (BBB) were isolated and analyzed using label-free quantification. MS data are available via ProteomeXchange with identifier PXD003519. Ninety
proteins were identified only in neurons, 260
proteins only in the BBB and 261
proteins in both cell types. Bioinformatics analyses revealed that repair processes, mainly related to synaptic plasticity, are outlined in microdissected neurons, with nonexclusive important functions found in the BBB. A total of 30
proteins showing p < 0.05 and fold-change> 2 between IC and CL areas were considered meaningful in this study: 13 in neurons, 14 in the BBB and 3 in both cell types. Twelve of these
proteins were selected as candidates and analyzed by immunohistofluorescence in independent brains. The MS findings were completely verified for neuronal SAHH2 and SRSF1 whereas the presence in both cell types of GABT and EAA2 was only validated in neurons. In addition, SAHH2 showed its potential as a prognostic
biomarker of neurological improvement when analyzed early in the plasma of
ischemic stroke patients. Therefore, the quantitative
proteomes of neurons and the BBB (or proteotypes) after human
brain ischemia presented here contribute to increasing the knowledge regarding the molecular mechanisms of
ischemic stroke pathology and highlight new
proteins that might represent putative
biomarkers of
brain ischemia or therapeutic targets.