Decrease and senescence of endothelial progenitor cells in patients with preeclampsia

BACKGROUND: In preeclampsia, the precise mechanism of impaired vascular function is still unclear. We hypothesized that cellular function of circulating endothelial progenitor cells (EPCs) might be impaired in patients with preeclampsia. OBJECTIVE: The objective of this study was to investigate the number and status of cellular senescence of EPCs in the circulation of women with preeclampsia. METHODS: Circulating EPCs were cultured from patients with preeclampsia (n = 8) and normotensive pregnant women (n = 7). EPC numbers were assessed by colony-forming unit (CFU) methodology as previously reported. In addition, to assess cellular senescence, we measured endogenous beta-galactosidase activity. Moreover, we assessed whether the serum level of C-reactive protein (CRP), a marker for systemic inflammation, was associated with cellular impairment of EPCs. RESULTS: The number of circulating EPCs was decreased in women with preeclampsia controls (median, 10.0 vs. 34.0 CFU; P < 0.01). The rate of cellular senescence was significantly increased in patients with preeclampsia (33.9%) compared with that in controls (22.9%; P < 0.05). Patients with preeclampsia were divided into two subgroups: the CRP-negative group (CRP, <0.1 mg/dl; n = 4) and the CRP-positive group (CRP, > or =0.1 mg/dl; n = 4). Interestingly, EPC CFU counts were markedly decreased in CRP-positive patients compared with those in CRP-negative patients (5.0 and 25.0 CFU, respectively; P < 0.05). Median values for cellular senescence were greater in the CRP-positive group than in the CRP-negative group, although this did not achieve statistical significance (43.5% and 33.3%, respectively; P = 0.12). CONCLUSION: Depletion and cellular aging of EPCs in patients with preeclampsia might be associated with endothelial dysfunction and could be affected by systemic inflammation.