Proteomic analysis shows differential protein expression in endothelial progenitor cells between healthy subjects and ischemic stroke patients

Abstract

Objective: An increase in the circulating concentration of endothelial progenitor cells (EPCs) is associated with a better outcome in patients with acute ischemic stroke. Likewise, EPCs are heterogeneous cells, with functional differences and different protein expressions. Our objective was to compare protein expressions of EPCs from ischemic stroke patients and healthy subjects.Methods: Eleven ischemic stroke patients and 11 healthy subjects, matched by age and gender, were included in this study. EPC colonies were defined as early outgrowth colony forming unit-endothelial cell. Cells were lysed and proteins were purified and separated on two-dimensional gels. Gel images were analyzed using the PDQuest software and protein differences between EPCs from ischemic stroke patients and healthy subjects were identified by mass spectrometry. Results were finally validated by western blot.Results: Proteomic analysis revealed three qualitative differences between EPCs from healthy subjects and ischemic stroke patients. Two of them, endoplasmatic reticulum protein-29 and CdC-42, were only expressed in EPCs from healthy subjects, whereas elongation factor-2 was only identified in EPCs from ischemic stroke patients. Furthermore, we identified one protein, peroxiredoxin-1, whose expression was 10 times stronger in ischemic stroke patients than in healthy subjects. Western blot analysis showed greater expression of endoplasmatic reticulum protein-29 in EPCs from healthy subjects and elongation factor-2 and peroxiredoxin-1 in EPCs from ischemic stroke patients.Conclusion: Proteomic analysis showed differences in protein expressions of EPCs from ischemic stroke patients and healthy subjects that may be involved in mechanisms related to functional impairment.