Thrombospondin: a new attachment protein in preretinal traction membranes.
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.
Department of Vitreoretinal Surgery, University Eye Clinic, Cologne, Germany.
M
M
Weller
P
P
Esser
M
M
Bresgen
K
K
Heimann
P
P
Wiedemann
D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D003930:Diabetic Retinopathy / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000378:metabolism; D005128:Eye Diseases / Q000378:metabolism; D005353:Fibronectins / Q000032:analysis; D005455:Fluorescent Antibody Technique; D006801:Humans; D010586:Phagocytes / Q000378:metabolism; D010980:Platelet Membrane Glycoproteins / Q000032:analysis*; D012160:Retina / Q000378:metabolism*; D012164:Retinal Diseases / Q000378:metabolism*; D019699:Thrombospondins; D011503:Transglutaminases / Q000032:analysis; D014822:Vitreous Body / Q000378:metabolism*; D014841:von Willebrand Factor / Q000032:analysis
D000911:Antibodies, Monoclonal; D005353:Fibronectins; D010980:Platelet Membrane Glycoproteins; D019699:Thrombospondins; D014841:von Willebrand Factor; D011503:Transglutaminases