Abstract Number: PB1700
Meeting: ISTH 2020 Congress
Theme: Platelets and Megakaryocytes » Platelet Function and Interactions
Background: Platelets contain mRNAs and synthesize proteins upon activation but have also miRNAs and the cytoplasmic enzymes of the miRNAs machinery, including Dicer1, the function of which is poorly understood. We previously showed that thrombin induces Dicer1 neosynthesis in normal platelets leading to miRNA223 maturation. Previous results showed that Dicer1 and miRNA223 levels are reduced in resting platelets from diabetic patients (T2DM), however the role of Dicer1 in miRNA processing and in the regulation of platelet reactivity after thrombin stimulation in T2DM is unknown.
Aims: To assess whether Dicer1 neosynthesis occurs in T2DM platelets upon activation and if this has an impact on miRNA, mRNA and target protein expression thus regulating platelet function.
Methods: Platelets from T2DM patients and healthy volunteers were ultrapurified by immunomagnetic beads and stimulated with thrombin for different intervals. Dicer1 and P2Y12 protein expression were analyzed by western blotting. Pre- and mature-miRNA223 and its target P2Y12 mRNA were quantified by RT-PCR.
Results: Dicer1 and miR223 expression increase both in control and T2DM platelets early after thrombin stimulation, but in T2DM platelets they decrease after 60 min while remain elevated for upto 240 min in controls. Platelet P2Y12 mRNA and protein expression decrease more rapidly in T2DM platelets (15 min) than in controls (60 min) but return to normal 4 hours after stimulation differently from controls where they remain suppressed.
Conclusions: Normal platelets regulate their own reactivity through the neosynthesis of Dicer1 and the downregulation of P2Y12, a self-regulatory mechanism reducing the reactivity of platelets previously exposed to traces of thrombin finalized to prevent unwarranted thrombus formation. In T2DM platelets this occurs too, but then Dicer1 and miR223 expression return rapidly to normal allowing the recovery of P2Y12 expression and thus of platelet reactivity. The derangement of this self-regulatory mechanism in T2DM may contribute to the platelet hyperreactivity of T2DM platelets.
To cite this abstract in AMA style:
Piselli E, Bury L, Manni G, Momi S, Fanelli C, Perriello G, Gresele P. An Activation-dependent Pathway Modulated by Dicer1 Neosynthesis and Down-regulating Platelet Reactivity Is Impaired in Diabetes [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/an-activation-dependent-pathway-modulated-by-dicer1-neosynthesis-and-down-regulating-platelet-reactivity-is-impaired-in-diabetes/. Accessed March 21, 2024.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/an-activation-dependent-pathway-modulated-by-dicer1-neosynthesis-and-down-regulating-platelet-reactivity-is-impaired-in-diabetes/