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Iniciación de la adhesión plaquetaria por detención en el fibrinógeno o translocación en el factor de von Willebrand
B Savage1, E Saldívar, Z M Ruggeri
1Roon Research Center for Arteriosclerosis and Thrombosis, Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, La Jolla, California 92037, USA.
Cell
|January 26, 1996
Resumen
La adhesión plaquetaria implica dos mecanismos: la integrina alfa IIb beta 3 para la detención inmediata pero de bajo corte, y la glicoproteína Ib alfa para el movimiento de alto corte y la eventual detención. Esta doble función es clave para la formación de coágulos de sangre.
Área de la Ciencia:
- Ingeniería Biomédica Ingeniería Biomédica.
- Hematología Hematología.
- Biología celular Biología celular.
Sus antecedentes:
- La adhesión de las plaquetas a las superficies trombogénicas es crítica para la hemostasis y la trombosis.
- Comprender los mecanismos moleculares de la adhesión plaquetaria bajo el flujo es esencial para el desarrollo de terapias antitrombóticas.
Objetivo del estudio:
- Para aclarar los distintos roles y la interacción de la integrina alfa IIb beta 3 y la glicoproteína Ib alfa en el inicio de la adhesión plaquetaria fluida.
- Para caracterizar la eficiencia y las limitaciones de cada mecanismo de adhesión a través de diferentes tasas de cizallamiento de pared.
Principales métodos:
- Se investigó la adhesión plaquetaria al fibrinógeno inmovilizado y al factor de von Willebrand en condiciones de flujo de cizallamiento controlado.
- Se analizó la contribución de la integrina alfa IIb beta 3 y la glicoproteína Ib alfa a las interacciones de la superficie plaquetaria.
Principales resultados:
- La integrina alfa IIb beta 3 media la rápida detención plaquetaria en el fibrinógeno, pero se limita a las tasas de cizallamiento por debajo de 600-900 s-1.
- La glicoproteína Ib alfa facilita la interacción plaquetaria sostenida con el factor de von Willebrand a tasas de cizallamiento superiores a 6000 s-1.
- La integrina alfa IIb beta 3 activada puede detener posteriormente las plaquetas en el factor de von Willebrand en condiciones de alto cizallamiento.
Conclusiones:
- Dos mecanismos de adhesión distintos, que difieren en la dependencia de la velocidad de cizallamiento y las interacciones moleculares, rigen el contacto inicial de las plaquetas con las superficies trombogénicas.
- La acción sinérgica de la integrina alfa IIb beta 3 y la unión de la glicoproteína Ib alfa al factor de von Willebrand es crucial para una trombogénesis efectiva, especialmente en condiciones de alto flujo.
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