Normal Platelet Integrin Function in Mice Lacking Hydrogen Peroxide-Induced Clone-5 (Hic-5).

ABSTRACT: Integrin ?IIb?3 plays a central role in the adhesion and aggregation of platelets and thus is essential for hemostasis and thrombosis. Integrin activation requires the transmission of a signal from the small cytoplasmic tails of the ? or ? subunit to the large extracellular domains resulting in conformational changes of the extracellular domains to enable ligand binding. Hydrogen peroxide-inducible clone-5 (Hic-5), a member of the paxillin family, serves as a focal adhesion adaptor protein associated with ?IIb?3 at its cytoplasmic tails. Previous studies suggested Hic-5 as a novel regulator of integrin ?IIb?3 activation and platelet aggregation in mice. To assess this in more detail, we generated Hic-5-null mice and analyzed activation and aggregation of their platelets in vitro and in vivo. Surprisingly, lack of Hic-5 had no detectable effect on platelet integrin activation and function in vitro and in vivo under all tested conditions. These results indicate that Hic-5 is dispensable for integrin ?IIb?3 activation and consequently for arterial thrombosis and hemostasis in mice.

SUBMITTER: Popp M 

PROVIDER: S-EPMC4501753 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature