title: Effects of the matricellular protein SPARC on human retinal pigment epithelial cell behavior.
abstract: OBJECTIVE
  To determine the effects of the matricellular protein SPARC (Secreted Protein, Acidic and Rich in Cysteine) on human retinal pigment epithelial (HRPE) cell behavior in vitro.
  
  
  METHODS
  Proliferation and migration assays were performed on HRPE cells exposed to various concentrations of SPARC. Additionally, HRPE cells were seeded on top of collagen matrices (a 2D model of the retinal scarring disorder known as proliferative vitreoretinopathy or PVR) and were exposed to SPARC over a 7 day period. Changes in matrix contraction were recorded.
  
  
  RESULTS
  HRPE cell proliferation was significantly inhibited at 1 and 10 microg/ml SPARC (p<0.01). SPARC protein did not stimulate HRPE cell migration at any of the concentrations used. SPARC did not significantly affect fibronectin-induced HRPE cell migration at SPARC concentrations up to 10 microg/ml. HRPE cell-seeded collagen matrices demonstrated a significant inhibition of matrix contraction by 1 and 10 microg/ml SPARC (t-test; p<0.02 and 0.001, respectively) compared to controls.
  
  
  CONCLUSIONS
  SPARC protein has anti-proliferative effects on HRPE cells in vitro. In addition, SPARC appears to have an inhibitory effect on HRPE-mediated contraction of 2D collagen matrices. These results are consistent with an important role for SPARC in modulating cell behavior in vitro and may indicate a role for SPARC in modifying HRPE cell activities during the development of PVR and other proliferative retinal diseases.
authors.affiliation: Unit of Ophthalmology, Department of Medicine, University of Liverpool, UK.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Hagan
authors.forename: Paul
authors.initials: P
authors.lastname: Hiscott
authors.forename: Carl Michael
authors.initials: CM
authors.lastname: Sheridan
authors.forename: David
authors.initials: D
authors.lastname: Wong
authors.forename: Ian
authors.initials: I
authors.lastname: Grierson
authors.forename: James
authors.initials: J
authors.lastname: McGalliard
mesh_terms: D000328:Adult; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D005353:Fibronectins / Q000494:pharmacology; D006801:Humans; D007223:Infant; D008297:Male; D015676:Osteonectin / Q000494:pharmacology*; D010857:Pigment Epithelium of Eye / Q000166:cytology*
chemical_list: D005353:Fibronectins; D015676:Osteonectin; D003094:Collagen