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Updated: Jul 10, 2026

A Microfluidic Flow Chamber Model for Platelet Transfusion and Hemostasis Measures Platelet Deposition and Fibrin Formation in Real-time
Published on: February 14, 2017
Release and activation of platelet latent TGF-beta in blood clots during dissolution with plasmin
D J Grainger1, L Wakefield, H W Bethell
1Department of Biochemistry, University of Cambridge, UK.
Abstract:
Transforming growth factor beta 1 (TGF-beta 1) is a platelet-derived cytokine involved in both normal wound healing and scarring. We show that human platelets contain two pools of latent TGF-beta 1, which constitute more than 95% of the total TGF-beta assayed in whole platelets. During clotting, one pool, the large latent TGF-beta complex consisting of latent TGF-beta binding protein (LTBP), the latency-associated peptide (LAP) and the 25-kD mature TGF-beta 1 dimer is released into the serum. A second pool, which contains LAP but not LTBP, is retained in the clot, but can be released by RGD peptide. When the clot is dissolved by plasmin this bound TGF-beta 1 is gradually activated and released. If similar mechanisms operate in vivo, the clot will act as a slow-release capsule of TGF-beta 1 activity during wound healing.
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