Altered microtubule equilibrium and impaired thrombus stability in mice lacking RanBP10

作者：Meyer Imke; Kunert Stefan; Schwiebert Silke; Hagedorn Ina; Italiano Joseph E Jr; Duetting Sebastian; Nieswandt Bernhard; Bachmann Sebastian; Schulze Harald^*

来源：Blood, 2012, 120(17): 3594-3602.

DOI：10.1182/blood-2012-01-401737

The crucial function of blood platelets in hemostasis is to prevent blood loss by stable thrombus formation. This process is driven by orchestrated mechanisms including several signal transduction cascades and morphologic transformations. The cytoplasmic microtubule modulator RanBP10 is a Ran and beta 1-tubulin binding protein that is essential for platelet granule release and mice lacking RanBP10 harbor a severe bleeding phenotype. In this study, we demonstrate that RanBP10-nullizygous platelets show normal adhesion on collagen and von Willebrand factor under flow conditions. However, using a ferric chloride-induced arterial thrombosis model, the formation of stable thrombi was significantly impaired, preventing vessel occlusion or leading to recanalization and thromboembolization. Delta-granule secretion was normal in mutant mice, whereas platelet shape change in aggregometry was attenuated. Lack of RanBP10 leads to increased beta 1-tubulin protein, which drives alpha-monomers into polymerized microtubules. In mutant platelets agonists failed to contract the peripheral marginal band or centralize granules. Pretreatment of wild-type platelets with taxol caused microtubule stabilization and phenocopied the attenuated shape change in response to collagen, suggesting that RanBP10 inhibits premature microtubule polymerization of beta 1-tubulin and plays a pivotal role in thrombus stabilization. (Blood. 2012;120(17):3594-3602)

• 出版日期2012-10-25