Thrombospondin: a new attachment protein in preretinal traction membranes

Eur J Ophthalmol. Jan-Mar 1992;2(1):10-4.

Abstract

Thrombospondin (TSP), an adhesive integrin-binding protein of plasma and platelets, was detected in preretinal traction membranes from patients with idiopathic (8/8) and traumatic (7/8) proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR) (6/8). TSP immunoreactivity was compared to the pattern of von Willebrand factor, plasma transglutaminase (blood coagulation factor XIII), fibronectin, and mononuclear phagocytes, using double-label immunofluorescence microscopy. TSP was partially colocalised with the endothelial cell marker, von Willebrand factor, in PDR. The codistribution of catalytic factor XIII and two cross-linking substrates, fibronectin and TSP, suggests a functional role of the enzyme in the extracellular matrix build-up in PVR and PDR. No significant TSP synthesis by mononuclear phagocytes was observed. Western blotting indicated a plasmin-mediated intravitreal breakdown of presumably plasmatic TSP in PVR and PDR.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal
  • Blotting, Western
  • Diabetic Retinopathy / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Endothelium, Vascular / metabolism
  • Eye Diseases / metabolism
  • Fibronectins / analysis
  • Fluorescent Antibody Technique
  • Humans
  • Phagocytes / metabolism
  • Platelet Membrane Glycoproteins / analysis*
  • Retina / metabolism*
  • Retinal Diseases / metabolism*
  • Thrombospondins
  • Transglutaminases / analysis
  • Vitreous Body / metabolism*
  • von Willebrand Factor / analysis

Substances

  • Antibodies, Monoclonal
  • Fibronectins
  • Platelet Membrane Glycoproteins
  • Thrombospondins
  • von Willebrand Factor
  • Transglutaminases