The immunoregulatory glycan-binding protein galectin-1 triggers human platelet activation

PACIENZA N; POZNER RG; BIANCO GA; D’ATRI LP; NEGROTTO S; MALAVER E; GÓMEZ RM; RABINOVICH GA; SCHATTNER M

FASEB JOURNAL

Año: 2008 vol. 22 p. 1113 - 1123

0892-6638

Platelet activation is a critical process during inflammation, thrombosis and cancer. Here we show that galectin-1, an endogenous lectin with immunoregulatory properties, plays a key role in human platelet activation and function. Galectin-1 binds to human platelets in a carbohydrate-dependent manner and synergizes with ADP or Thrombin to induce platelet aggregation and ATP release. Furthermore, galectin-1 induces up- regulation of P-selectin and GPIIIa expression, promotes shedding of microvesicles and triggers conformational changes in GPIIb/IIIa. In addition, exposure to this lectin favors the formation of microparticules and induces the generation of leukocyte-platelet aggregates. A further mechanistic analysis revealed the involvement of Ca2+ and cyclic nucleotide-dependent pathways in galectin-1-mediated control of platelet activation. Finally, expression of endogenous galectin-1 in human platelets contributes to ADP- induced aggregation in a carbohydrate-dependent manner. Our study reveals a novel unrecognized role for galectin-1 in the control of platelet physiology with potential implications in thrombosis, inflammation and metastasis.