Anti–miR-148a regulates platelet FcγRIIA signaling and decreases thrombosis in vivo in mice

• Published in: Blood 2015-12, Vol.126 (26), p.2871-2881
• Main Authors: Zhou, Yuhang, Abraham, Shaji, Andre, Pierrette, Edelstein, Leonard C., Shaw, Chad A., Dangelmaier, Carol A., Tsygankov, Alexander Y., Kunapuli, Satya P., Bray, Paul F., McKenzie, Steven E.
• Format: Article
• Language: English
• Subjects: Animals; Blood Platelets - metabolism; Gene Expression Regulation; Gene Knockdown Techniques; Genetic Predisposition to Disease; Genome-Wide Association Study; Humans; Mice; Mice, Transgenic; MicroRNAs - genetics; Platelet Activation - genetics; Protein Tyrosine Phosphatases - biosynthesis; Protein Tyrosine Phosphatases - genetics; Receptors, IgG - metabolism; Signal Transduction - physiology; Thrombocytopenia - genetics; Thrombosis - genetics; Thrombosis and Hemostasis
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2015-02-631135

Fc receptor for IgG IIA (FcγRIIA)–mediated platelet activation is essential in heparin-induced thrombocytopenia (HIT) and other immune-mediated thrombocytopenia and thrombosis disorders. There is considerable interindividual variation in platelet FcγRIIA activation, the reasons for which remain unclear. We hypothesized that genetic variations between FcγRIIA hyper- and hyporesponders regulate FcγRIIA-mediated platelet reactivity and influence HIT susceptibility. Using unbiased genome-wide expression profiling, we observed that human hyporesponders to FcγRIIA activation showed higher platelet T-cell ubiquitin ligand-2 (TULA-2) mRNA expression than hyperresponders. Silent interfering RNA-mediated knockdown of TULA-2 resulted in hyperphosphorylation of spleen tyrosine kinase following FcγRIIA activation in HEL cells. Significantly, we found miR-148a-3p targeted and inhibited both human and mouse TULA-2 mRNA. Inhibition of miR-148a in FcγRIIA transgenic mice upregulated the TULA-2 level and reduced FcγRIIA- and glycoprotein VI–mediated platelet αIIbβ3 activation and calcium mobilization. Anti–miR-148a also reduced thrombus formation following intravascular platelet activation via FcγRIIA. These results show that TULA-2 is a target of miR-148a-3p, and TULA-2 serves as a negative regulator of FcγRIIA-mediated platelet activation. This is also the first study to show the effects of in vivo miRNA inhibition on platelet reactivity. Our work suggests that modulating miR-148a expression is a potential therapeutic approach for thrombosis. •TULA-2 negatively regulates platelet FcγRIIA signaling by dephosphorylating Syk.•miR-148a targets TULA-2 and inhibition of miR-148a decreases FcγRIIA-mediated platelet activation and thrombosis in vivo.