title: Different populations of circulating endothelial cells in patients with age-related macular degeneration: a novel insight into pathogenesis.
abstract: OBJECTIVE
  Circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) may serve as novel markers of endothelial dysfunction. The presence and clinical implications of CECs and the expression of endothelin (ET)-1, one of the most potent vasoconstrictors, have not been evaluated in patients with the neovascular form of age-related macular degeneration (AMD). This study was conducted to determine the different populations of endothelial cells (ECs) in the peripheral blood of AMD patients and to correlate these findings with the expression of ET-1 and the cytokines and growth factors responsible for EC migration and function.
  
  
  METHODS
  Peripheral blood samples were collected from 29 patients with diagnosed neovascular AMD and from 38 healthy control subjects. CD133(-)CD144(+) CECs and CD34(+)CD133(+)CD144(+) EPCs were counted and analyzed by flow cytometry. The intracellular expression of ET-1 in peripheral blood nuclear cells (PBNCs) was studied by using qRT-PCR, Western blot, and immunocytofluorescence assays, and ET-1, IGF-1, VEGF, SDF-1, and HGF plasma concentrations were measured in enzyme-linked immunosorbent assays.
  
  
  RESULTS
  Increased CECs and EPCs were found in the AMD patients compared with the counts in healthy individuals. The expression of intracellular ET-1 was significantly elevated in PBNCs from the AMD patients compared with the control subjects. In addition a significantly higher plasma concentration of IGF-1 was observed, but a lower SDF-1 level in the group of AMD patients.
  
  
  CONCLUSIONS
  These findings suggest that circulating endothelial cells, together with high ET-1 content, may contribute to the development of AMD. Further prospective investigations on the mechanism involved may be relevant to the potential treatment of this disease.
authors: Department of Histology and Embryology, Pomeranian Medical University, Szczecin, Poland.
authors: Anna
authors: A
authors: Machalinska
authors: Krzysztof
authors: K
authors: Safranow
authors: Violetta
authors: V
authors: Dziedziejko
authors: Katarzyna
authors: K
authors: Mozolewska-Piotrowska
authors: Edyta
authors: E
authors: Paczkowska
authors: Patrycja
authors: P
authors: Klos
authors: Ewa
authors: E
authors: Pius
authors: Katarzyna
authors: K
authors: Grymula
authors: Barbara
authors: B
authors: Wiszniewska
authors: Danuta
authors: D
authors: Karczewicz
authors: Boguslaw
authors: B
authors: Machalinski
mesh_terms: D000368:Aged; D015703:Antigens, CD; D001775:Blood Circulation; D015153:Blotting, Western; D016207:Cytokines / Q000378:metabolism; D019332:Endothelin-1 / Q000097:blood; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008268:Macular Degeneration / Q000097:blood* / Q000209:etiology; D008297:Male; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D016207:Cytokines; D019332:Endothelin-1; D042461:Vascular Endothelial Growth Factor A; D007334:Insulin-Like Growth Factor I