title: Impairment of two types of circulating endothelial progenitor cells in patients with glucocorticoid-induced avascular osteonecrosis of the femoral head.
abstract: OBJECTIVE
  This study examined whether abnormalities of early EPCs and endothelial colony forming cells (ECFCs) are present and compared their functions in glucocorticoid (GC)-induced avascular osteonecrosis of the femoral head (ANFH).
  
  
  METHODS
  Early EPCs and endothelial colony forming cells (ECFCs) were obtained from 33 patients with glucocorticoid-induced ANFH and 33 age- and sex-matched control subjects. Cells were isolated, in vitro cultured and studied by Flow Cytometry and Immunofluorescence. Colony-forming unit counts were observed from 33 patients and 33 healthy controls. Growth kinetics, migratory capacity to multiple chemo-attractants, in vitro tube formation capacity and cytokine (vascular endothelial growth factor and stromal cell-derived factor-1) levels in supernatants of two types of EPCs were assayed in ANFH patients and matched controls (n=4).
  
  
  RESULTS
  Mean numbers of colonies formed by both types of EPCs were decreased in ANFH patients (Early EPCs: 2.42±1.46 versus 4.52±2.00, p<0.05; ECFCs: 0.62±0.55 versus 1.12±0.82, p<0.05). Early EPCs from ANFH patients showed impaired migratory capacity (63.8±11.7 versus 152.3±12.4, p<0.001) and VEGF secretion (50.8±7.2 pg/ml versus 62.8±10.1 pg/ml, p<0.05). ECFCs from ANFH patients showed decreased tube formation capacity (7.1±2.7 versus 23.8±4.3, p<0.001) and proliferation.
  
  
  CONCLUSIONS
  Early EPCs and ECFCs were impaired in number and function in GC-induced ANFH, and their distinct reduced capacity profiles might reflect different roles they played in endothelial dysfunction of GC-induced ANFH.
authors.affiliation: Department of Orthopedics, Union Hospital, Tongji Medical College, Science and Technology of Huazhong University, Wuhan 430022, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.forename: Shuhua
authors.initials: S
authors.lastname: Yang
authors.forename: Yong
authors.initials: Y
authors.lastname: Feng
authors.forename: Xinghuo
authors.initials: X
authors.lastname: Wu
authors.forename: Dong
authors.initials: D
authors.lastname: Chen
authors.forename: Qian
authors.initials: Q
authors.lastname: Yu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
mesh_terms: D000328:Adult; D042783:Endothelial Cells / Q000473:pathology*; D005260:Female; D005271:Femur Head Necrosis / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D005938:Glucocorticoids / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013234:Stem Cells / Q000473:pathology*; D055815:Young Adult
chemical_list: D005938:Glucocorticoids