Selective inhibition of Panx1 channels decreases hemostasis and thrombosis in vivo

Filippo Molica; Merlijn J Meens; Graziano Pelli; Aurélie Hautefort; Yalin Emre; Beat A Imhof; Pierre Fontana; Eliana Scemes; Sandrine Morel; Brenda R Kwak

doi:10.1016/j.thromres.2019.09.028

Selective inhibition of Panx1 channels decreases hemostasis and thrombosis in vivo

Thromb Res. 2019 Nov:183:56-62. doi: 10.1016/j.thromres.2019.09.028. Epub 2019 Oct 18.

Authors

Affiliations

¹ Dept of Pathology and Immunology, University of Geneva, Geneva, Switzerland.
² Division of Angiology and Haemostasis, Geneva University Hospitals and Geneva Platelet Group, University of Geneva, Geneva, Switzerland.
³ Dept of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA.
⁴ Dept of Pathology and Immunology, University of Geneva, Geneva, Switzerland; Dept of Medical Specializations - Cardiology, University of Geneva, Geneva, Switzerland. Electronic address: Brenda.KwakChanson@unige.ch.

PMID: 31669824
DOI: 10.1016/j.thromres.2019.09.028

Abstract

Background: Hemostasis is a tightly regulated physiological process to rapidly induce hemostatic plugs at sites of vascular injury. Inappropriate activation of this process may lead to thrombosis, i.e. pathological blood clot formation in uninjured vessels or on atherosclerotic lesions. ATP release through Pannexin1 (Panx1) membrane channels contributes to collagen-induced platelet aggregation in vitro.

Objective: To investigate the effects of genetic and pharmacological inhibition of Panx1 on hemostasis and thrombosis in vivo.

Results: Bleeding time after tail clipping was increased by 2.5-fold in Panx1^-^/^- mice compared to wild-type controls, suggesting that Panx1 deficiency impairs primary hemostasis. Wire myography on mesenteric arteries revealed diminished vasoconstriction in response to phenylephrine or U446619 in Panx1^-^/^- mice. Mice with platelet-specific deletion of Panx1 (Panx1^PDel) displayed 2-fold longer tail bleeding times than Panx1^fl/fl controls. Moreover, venous thromboembolism (VTE) after injection of collagen/epinephrine in the jugular vein was reduced in Panx1^-^/^- and Panx1^PDel mice. Panx1^PDel mice also showed reduced FeCl₃-induced thrombosis in mesenteric arteries. BrilliantBlue-FCF, a Panx1 channel inhibitor, decreased collagen-induced platelet aggregation in vitro, increased tail bleeding time and reduced VTE in wild-type mice. Furthermore, we developed a specific Panx1 blocking antibody targeting a Panx1 extracellular loop, which reduced ATP release from platelets in vitro. Treating wild-type mice with this antibody increased tail bleeding time and decreased VTE compared to control antibody.

Conclusions: Panx1 channel deletion or inhibition diminishes clot formation during hemostasis and thrombosis in vivo. Blocking Panx1 channels may be an attractive strategy for modulating platelet aggregation in thrombotic disease.

Keywords: Hemostasis; Mice; Pathology; Platelets; Thrombosis.

MeSH terms

Animals
Connexins / antagonists & inhibitors*
Hemostasis / physiology*
Humans
Male
Mice
Nerve Tissue Proteins / antagonists & inhibitors*
Thrombosis / therapy*

Substances

Connexins
Nerve Tissue Proteins
PANX1 protein, human