The disulfide isomerase ERp72 supports arterial thrombosis in mice.

Abstract

Several CGHC motif-containing disulfide isomerases support thrombosis. We here report that endoplasmic reticulum protein 72 (ERp72), with 3 CGHC redox-active sites (ao, a, and a'), supports thrombosis. We generated a new conditional knockout mouse model and found that Tie2-Cre/ERp72fl/fl mice with blood and endothelial cells lacking ERp72 had prolonged tail bleeding times and decreased platelet accumulation in laser-induced cremaster arteriole injury and FeCl3-induced mesenteric arterial injury. Fibrin deposition was decreased in the laser injury model. Both platelet and fibrin accumulation defects were fully rescued by infusion of recombinant ERp72 containing functional a and a' CGHC motifs (ERp72(oo-ss-ss)). Infusion of ERp72 containing inactivated a and a' CGHC motifs (ERp72(ss-oo-oo)) inhibited platelet accumulation and fibrin deposition in wild-type mice. Infusion of ERp72(oo-ss-ss) into β3-null mice increased fibrin deposition in the absence of platelets. ERp72-null platelets had defective aggregation, JON/A binding, P-selectin expression, and adenosine triphosphate (ATP) secretion. The aggregation and ATP secretion defects were fully rescued by ERp72(oo-ss-ss) but partially rescued by ERp72(ss-oo-ss) and ERp72(ss-ss-oo). Aggregation and ATP secretion of human platelets was potentiated by ERp72(oo-ss-ss) but inhibited by ERp72(ss-oo-ss) and ERp72(ss-ss-oo). These data suggest that both the a and a' active sites are required for platelet function. ERp72 bound poorly to β3-null mouse platelets, and the addition of ERp72(oo-ss-ss) to human platelets generated thiols in αIIbβ3, suggesting a direct interaction of ERp72 with αIIbβ3. Defective aggregation of ERp72-null platelets was recovered by ERp72, but not other thiol isomerases. In summary, ERp72 plays a critical role in platelet function and coagulation through the a and a' CGHC motifs.

• Authors: Junsong Zhou, Yi Wu, Fengwu Chen, Lu Wang, Lubica Rauova, Vincent M Hayes, Mortimer Poncz, Hong Li, Tong Liu, Junling Liu, David W Essex
• Journal: Blood (Blood) Vol. 130 Issue 6 Pg. 817-828 (08 10 2017) ISSN: 1528-0020 [Electronic] United States
• PMID: 28576878 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural)
• Copyright: © 2017 by The American Society of Hematology.

Chemical References

• Membrane Glycoproteins
• Platelet Glycoprotein GPIIb-IIIa Complex
• endoplasmic reticulum glycoprotein p72

Topics

• Animals
• Blood Platelets (metabolism, pathology)
• Humans
• Membrane Glycoproteins (analysis, genetics, metabolism)
• Mice
• Mice, Knockout
• Platelet Activation
• Platelet Glycoprotein GPIIb-IIIa Complex (metabolism)
• Thrombosis (genetics, metabolism, pathology)