Review Article

Platelet-Rich Plasma Peptides: Key for Regeneration

Table 2

Some bioactive peptides present in the alpha granules of platelets.

General activity categoriesSpecific moleculesCytogenetic locationBiologic activities

Tissue factor pathway inhibitor; TFPI2q32.1Regulates the tissue factor-(TF-) dependent pathway of blood coagulation
Kininogen; KNG3q27.3Plays an important role in assembly of the plasma kallikrein
Growth arrest-specific 6; GAS613q34Stimulates cell proliferation
Multimerin; MMRN4q22Carrier protein for platelet factor V
Clotting factors and related proteinsAntithrombin; AT1q25.1Is the most important inhibitor of thrombin
Protein S; PROS13q11.1Inhibits blood clotting
Coagulation factor V; F51q24.2Acts as a cofactor for the conversion of prothrombin to thrombin by factor Xa
Coagulation factor XI; F114q35.2It participates in blood coagulation as a catalyst in the conversion of factor IX to factor IXa in the presence of calcium ions

Plasminogen; PLG6q26Induces plasmin production (leads to fibrinolysis)
Plasminogen activator inhibitor 1; PAI17q22.1Regulation of plasmin production
Alpha-2-plasmin inhibitor17p13.3Inactivation of plasmin
Fibrinolytic factors and related proteinsOsteonectin; ON5q33.1Inhibits cell-cycle progression and influences the synthesis of extracellular matrix (ECM)
Histidine-rich glycoprotein; HRG3q27.3Interacts with heparin and thrombospondin
Thrombin-activatable fibrinolysis inhibitor; TAFI13q14.13Attenuates fibrinolysis
Alpha-2-Macroglobulin; A2M12p13.31Carrier of specific growth factors and induces cell signaling

Tissue inhibitor of metalloproteinase 4; TIMP43p25.2Inhibits matrix metalloproteinases (MMPs), a group of peptidases involved in degradation of the extracellular matrix
Complement component 1 inhibitor; C1NH11q12.1Inhibits serine proteinases including plasmin, kallikrein, and coagulation factors XIa and XIIa
Proteases and antiproteasesAlpha-1-antitrypsin (serpin peptidase inhibitor)14q32.13Acute phase protein, inhibits a wide variety of proteases and enzymes
Nexin 2; SNX25q23.2Modulates intracellular trafficking of proteins to various organelles

Platelet factor 4; PF44q13.3Inhibition of angiogenesis
Basic proteinsβ-thromboglobulin (Pro-platelet basic protein; PPBP)4q13.3Platelet activation, inhibition of angiogenesis
Endostatin (Collagen, type XVIII, Alpha-1; COL18A1)21q22.3Inhibitors of endothelial cell migration and angiogenesis

Fibrinogen; FG4q31.3Blood clotting cascade (fibrin clot formation)
Fibronectin; FN2q35Binds to cell-surface integrins, affecting cell adhesion, cell growth, migration, and differentiation
Adhesive proteinsVitronectin; VTN17q11.2Induces cell adhesion, chemotaxis
Thrombospondin I; THBS115q14Inhibition of angiogenesis
Laminin-818p11.31-p11.23Modulates cell contact interactions

It is described general activity categories, specific molecules, cytogenetic location and biologic activities. Furthermore, alpha granules include growth factors of Table 1, membrane glycoproteins, and others proteins like albumin and immunoglobulins.