title: Oestrogen stimulates endothelial progenitor cells via oestrogen receptor-alpha.
abstract: BACKGROUND
  Oestrogens play an important protective role on the vascular system. The endothelial cell layer is a direct target for these hormones, and expresses at least two oestrogen receptors, ER-alpha and ER-beta. Recent studies have shown that vascular healing is significantly modulated by circulating bone marrow-derived cells. A subset of these stem cells, endothelial progenitor cells (EPCs), have recently been described as a population of pluripotent cells within the peripheral blood capable of differentiating into endothelial cells.
  
  
  OBJECTIVE
  In the present study we investigated the expression of ER-alpha and ER-beta on human EPCs and the effect that oestrogens have on the function of EPCs in vitro.
  
  
  METHODS
  EPCs were isolated and cultured from healthy donors. RT-PCR, western blotting and immunohistochemistry were used to assess expression of ER-alpha and ER-beta. Proliferation and CFU assays were used to assess the response of EPCs to different doses of 17,beta-oestradiol.
  
  
  METHODS
  Expression of ER-alpha and ER-beta in EPCs, and the effect of 17,beta-oestradiol on proliferation of EPCs.
  
  
  RESULTS
  Human EPCs express ER-alpha mRNA and protein. 17,beta-oestradiol increases proliferation of EPCs and CFU in a dose-dependent manner.
  
  
  CONCLUSIONS
  Human EPCs express ER-alpha but not ER-beta, and oestrogens can stimulate the proliferation of these cells in vitro. Oestrogens exert these effects at concentrations that are usually reached during stimulation for in vitro fertilization in women, and therefore further studies are needed to clarify the clinical significance of these effects.
authors.affiliation: Department of Histology, Microbiology and Medical Biotechnologies, Centre for Male Gamete Cryopreservation, University of Padua, Padova, Italy. carlo.foresta@unipd.it
authors.forename: Carlo
authors.initials: C
authors.lastname: Foresta
authors.forename: Daniela
authors.initials: D
authors.lastname: Zuccarello
authors.forename: Andrea
authors.initials: A
authors.lastname: Biagioli
authors.forename: Luca
authors.initials: L
authors.lastname: De Toni
authors.forename: Elisa
authors.initials: E
authors.lastname: Prana
authors.forename: Valentina
authors.initials: V
authors.lastname: Nicoletti
authors.forename: Guido
authors.initials: G
authors.lastname: Ambrosini
authors.forename: Alberto
authors.initials: A
authors.lastname: Ferlin
mesh_terms: D015153:Blotting, Western; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003600:Cytosol / Q000737:chemistry / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology*; D047628:Estrogen Receptor alpha / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric; D013234:Stem Cells / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D013268:Stimulation, Chemical
chemical_list: D047628:Estrogen Receptor alpha; D012333:RNA, Messenger; D004958:Estradiol