Oxidized PDI promotes thrombus formation in oxidative stress

M Moua Yang (Division of Hematology and Oncology, Department of Medicine, University of Washington School of Medicine and Bloodworks Northwest Research Institute, Seattle (M.Y., Q.P.K.).) O Osamede C. Owegie (1Bloodworks Northwest Research Institute, Seattle, WA) A Anika Patel (3Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA) Q Quinn P. Kennedy (Division of Hematology and Oncology, Department of Medicine, University of Washington School of Medicine and Bloodworks Northwest Research Institute, Seattle (M.Y., Q.P.K.).) J James T. Flaumenhaft (3Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA) M Mathivanan Chinnaraj (4Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO) N Nathan Ponzar (4Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO) E Emmy M. Fulcidor (3Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA) M Mario C. Rico (5Department of Cardiovascular Sciences, Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA) A Amit Bhowmik (6Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL) K Kate S. Carroll (6Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL) D Diane E. Handy (7Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA) J Joseph Loscalzo (Department of Medicine, Brigham and Women’s Hospital, Boston) D David W. Essex (5Department of Cardiovascular Sciences, Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA) N Nicola Pozzi (4Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO) R Robert Flaumenhaft

Abstract

Abstract Protein disulfide isomerase (PDI) functions in thrombus formation in vivo and represents a viable target for antithrombotic therapy. PDI is a redox sensor that can either reduce or oxidize substrates depending on the redox environment. However, whether PDI functions primarily as a reductase or an oxidase in the context of thrombus formation remains unknown. Here, we used pharmacological and genetic approaches along with PDI mutants to determine how the PDI redox state affects thrombus formation. LOC14, which inhibits PDI reductase activity and induces PDI oxidation, promoted thrombus formation in arteries exposed to ferric chloride and enhanced laser injury–induced platelet accumulation and fibrin formation in cremaster arterioles. Blocking antibodies targeting PDI reversed the prothrombotic effect of LOC14. Evaluation of sulfenylation-mediated PDI oxidation using the C53A, C56A, R120D, and T101A PDI mutants showed that the sulfenylation mechanism of PDI resembles that of hydrogen peroxide (H2O2) reduction by peroxiredoxins. These studies identified PDI mutants that failed to undergo H2O2-mediated oxidation, but showed normal reductase activity. When tested in vivo, either wild-type PDI or the R120D mutant fully restored normal thrombus formation following morpholino-induced knockdown of PDI or in mice with platelet-specific knockout of PDI. In contrast, the sulfenylation-impaired R120D mutant PDI was unable to fully restore thrombus formation in the setting of oxidative stress induced in mice by genetic deletion of glutathione peroxidase 3 or by infusion of oxidized low-density lipoproteins. These studies show that PDI-catalyzed oxidation drives thrombosis and demonstrates a mechanism of peroxide-mediated oxidation of PDI that contributes to the prothrombotic response of oxidative stress.

Article Details

Journal Blood
Volume / Issue Vol. 148, Issue 3
Published July 16, 2026
Pages 376-388
ISSN 0006-4971
Publisher Elsevier BV

Journal Info

Blood

Elsevier BV

ISSN: 0006-4971 Health Sciences

Authors (16)

M

Moua Yang

Division of Hematology and Oncology, Department of Medicine, University of Washington School of Medicine and Bloodworks Northwest Research Institute, Seattle (M.Y., Q.P.K.).

O

Osamede C. Owegie

1Bloodworks Northwest Research Institute, Seattle, WA

A

Anika Patel

3Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA

Q

Quinn P. Kennedy

Division of Hematology and Oncology, Department of Medicine, University of Washington School of Medicine and Bloodworks Northwest Research Institute, Seattle (M.Y., Q.P.K.).

J

James T. Flaumenhaft

3Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA

M

Mathivanan Chinnaraj

4Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO

N

Nathan Ponzar

4Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO

E

Emmy M. Fulcidor

3Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA

M

Mario C. Rico

5Department of Cardiovascular Sciences, Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA

A

Amit Bhowmik

6Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL

K

Kate S. Carroll

6Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL

D

Diane E. Handy

7Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA

J

Joseph Loscalzo

Department of Medicine, Brigham and Women’s Hospital, Boston

D

David W. Essex

5Department of Cardiovascular Sciences, Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA

N

Nicola Pozzi

4Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO

R

Robert Flaumenhaft