The Role of Plasma Fibronectin in Platelet Adhesion to Collagen

Abstract

Human washed platelets were eluted from columns of Sepharose 4B linked to different preparations of collagen in order to evaluate cell adhesion. Collagen preparations characterized by low and high affinity toward platelets were identified. In our experiments, fibronectin purified from human plasma modified platelet adhesiveness, though not dramatically. When washed platelets, resuspended in a buffer containing fibronectin, were filtered on a low-affinity collagen-Sepharose, a significant increase in their adhesion occurred. A similar modification could be observed when platelets were allowed to adhere to the same collagen-Sepharose preconditioned with fibronectin. The effect of fibronectin was otherwise negligible when the high-affinity collagen was used for the experiments.

Defect of Platelet Aggregation and Adhesion Induced by Autoantibodies Against Platelet Glycoprotein IIIa

“…Fibrillar insoluble type I collagen (Sigma Chemical Co., St Louis, MO) was noncovantly immobilized on Sepharose 4B (Pharmacia, Uppsala, Sweden) by the method of Zabinski et al (12). PRP (platelet count 250 × 10 9 /1) was obtained from blood anticoagulated with EDTA (3 mM, final concentration) and it was passed through 2 ml columns of collagen-Sepharose 4B as previously reported (13). The adhesion of the patient's platelets was always studied in parallel with that of platelets from normal subjects.…”

Mechanisms of thrombin-induced modifications of human platelet cytoskeleton

“…A suspension of washed human platelets was prepared as previously described (Balduini et al, 1984) Brass et al (1976) with some modifications (Balduini et al, 1984).…”

Thrombin increases the adhesion of washed human platelets to collagen

“…well as a receptor for collagen on platelet surface (Chiang & Kang, 1982) have been described. Moreover, the role of some blood components in platelet-collagen interaction has been investigated (Mant & Bach, 1981;Bang et al, 1972;Balduini et al, 1984;Cowan et al, 1981). In vivo, when the vessel wall is damaged and platelet-subendothelium interaction takes place, the coagulation process is activated and additional substances are available for interaction with platelet surface or collagen.…”