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El anclaje del glicosil fosfatidilinositol en el inhibidor de la vía del factor tisular
Jing Zhang1, Orlando Piro, Lan Lu
1Division of Hematology, Barnes-Jewish Hospital at Washington University Medical Center, St Louis, Mo, USA.
Circulation
|July 2, 2003
Resumen
El inhibidor de la vía del factor tisular (TFPI) en las células endoteliales está anclado a través del glicosilfosfatidilinositol (GPI) y otras proteínas. Esta asociación de membrana es crucial para regular la coagulación localmente.
Área de la Ciencia:
- Biología de las células endoteliales.
- La hemostasis y la trombosis.
- Biología molecular La biología molecular.
Sus antecedentes:
- El endotelio es una fuente primaria de inhibidor de la vía del factor tisular (TFPI), un regulador clave de la coagulación.
- Una cantidad significativa de TFPI endotelial permanece unida a la superficie celular.
Objetivo del estudio:
- Para investigar el mecanismo de la localización de TFPI en la superficie de las células endoteliales.
- Para determinar el papel de los anclajes de glicosilfosfatidilinositol (GPI) en la asociación de la membrana de la TFPI.
Principales métodos:
- Tratamiento de las células endoteliales cultivadas con fosfolipasa C (PI-PLC) específica para el fosfatidilinositol.
- Análisis de la liberación de TFPI y la presencia de ancla de GPI utilizando anticuerpos específicos.
- Comparación de la expresión de ARNm de TFPIalpha y TFPIbeta.
- Estudios de expresión en células de ovario de hámster chino (CHO).
Principales resultados:
- El tratamiento con PI-PLC liberó aproximadamente el 80% del TFPI asociado a la superficie de las células endoteliales.
- Una parte del TFPI liberado contenía un anclaje GPI.
- Las células endoteliales expresan tanto el ARNm TFPIalpha como el TFPIbeta.
- En las células CHO, el TFPIbeta está anclado en el GPI, mientras que el TFPIalpha se secreta, pero una pequeña fracción asociada a la superficie es sensible al PI-PLC.
Conclusiones:
- Tanto los mecanismos directos (TFPIbeta) como los indirectos (TFPIalpha) mediados por GPI contribuyen a la localización de TFPI en las superficies celulares.
- La asociación de la membrana TFPI es esencial para su función reguladora localizada en la coagulación.
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