Decreased levels and function of circulating endothelial progenitor cells in unruptured intracranial saccular aneurysm patients

Circulating endothelial progenitor cells (EPCs) play a critical role in maintaining endothelial integrity and keeping vascular homeostasis. Previously, we reported that EPCs were involved in repair and remodeling of aneurismal wall. In the present study, we verified this hypothesis by investigating the proliferative ability and count of EPCs in peripheral blood of patients with unruptured intracranial aneurysms (UIAs). Twenty-four patients with UIAs (UIA group) and 24 negative controls (control group) were included in this study. Peripheral blood monocytes (PBMCs) were harvested and selectively cultured. The colony-forming ability of cultured cells was analyzed and the biological functions were examined by testing the adsorption of ulex europaeus agglutinin-1 labeled by fluorescein isothiocyanate and acetylated low-density lipoprotein internalization. The migratory and adhesive ability of cultured EPCs were assessed. In vitro cultured PBMCs were identified as EPCs by examining surface markers CD34, CD133 and vascular endothelial growth factor receptor 2 using flow cytometry. EPCs from UIA group possessed significantly decreased proliferative, migratory and adhesive capacities compared with EPCs from control group. Furthermore, EPCs count in UIA group was significantly decreased. Collectively, these results indicated that the circulating EPCs of UIA patients may be involved in intracranial aneurysm repair and remodeling.