Attenuation of Atherosclerosis with PAR4 Deficiency: A Potential Role of Hematopoietically Expressed PAR4 in Atherosclerosis - Brief Report

Caris A. Wadding-Lee; Megan Jay; Shannon M. Shearer; Tyler W. Benson; Anthony Spuzzillo; Deborah A. Howatt; Joel Thompson; Benjamin E. Tourdot; Alan Daugherty; Nigel Mackman; A. Phillip Owens

doi:10.1161/ATVBAHA.124.322068

Attenuation of Atherosclerosis with PAR4 Deficiency: A Potential Role of Hematopoietically Expressed PAR4 in Atherosclerosis - Brief Report

Caris A. Wadding-Lee, Megan Jay, Shannon M. Shearer, Tyler W. Benson, Anthony Spuzzillo, Deborah A. Howatt, Joel Thompson, Benjamin E. Tourdot, Alan Daugherty, Nigel Mackman, A. Phillip Owens

Research output: Contribution to journal › Article › peer-review

Abstract

BACKGROUND: Cardiovascular disease is a significant burden globally and, despite current therapeutics, remains the leading cause of death. PAR (protease-activated receptor) 4 is a receptor highly expressed by hematopoietic cells, strongly activated by thrombin, and plays a vital role in platelet activation and aggregation. However, the role of PAR4 in atherothrombotic disease remains understudied. METHODS: Mice on a low-density lipoprotein receptor-deficient (Ldlr^-/-) background were bred with Par4-deficient (Par4^-/-) mice to create Ldlr^-/-/Par4^+/+ and Ldlr^-/-/Par4^-/- cousin lines. Mice were fed high-fat (42%) and high-cholesterol (0.2%) Western diet for 12 weeks for all studies. Bone marrow transplant studies were conducted by irradiating Ldlr^-/-/Par4+/+ and Ldlr^-/-/Par4^-/- mice with 550 rads (2×, 4 hours apart) and then repopulated with Par4^+/+ or Par4^-/- bone marrow. To determine whether the effects of thrombin were mediated solely by PAR4, the thrombin inhibitor dabigatran was added to the Western diet. RESULTS: We observed higher abundance of PAR4 in arteries with atherosclerosis in mouse and human lesions versus healthy controls. Using a global deletion of PAR4, we observed an attenuation in atherosclerosis versus Par4+/+ mice. Bone marrow transplant studies demonstrated these effects were due to hematopoietic cells. When observing whether PAR4 activation via thrombin contributes to atherosclerotic development, Ldl^-/-/Par4^-/- mice given dabigatran did not further decrease their atherosclerotic burden. Differences between apoE-deficient (apoE^-/-) and Ldl^-/- platelets were assessed for changes in reactivity. PAR4 appeared to be acting independent of PAR1, as there were no changes with the addition of dabigatran to Par4^-/- mice. apoE^-/- platelets were hyperreactive compared with Ldlr^-/- platelets. CONCLUSIONS: We conclude that hematopoietic-derived PAR4 plays a vital role in the development and progression of atherosclerosis. More specifically, we observe thrombin-activated PAR4 contributes to the progression. Specifically, targeting of PAR4 may be a potential therapeutic target for cardiovascular disease.

Original language	English
Pages (from-to)	901-909
Number of pages	9
Journal	Arteriosclerosis, Thrombosis, and Vascular Biology
Volume	45
Issue number	6
DOIs	https://doi.org/10.1161/ATVBAHA.124.322068
State	Published - Jun 1 2025

Bibliographical note

Publisher Copyright:
© 2025 American Heart Association, Inc.

Funding

This work was supported by the National Institutes of Health National Heart, Lung, and Blood Institute grants 5R00-HL116786-05 (A.P. Owens), 5R01-HL-141404-06 (A.P. Owens), and F31-HL170534-01 (C.A. Wadding-Lee).

Funders	Funder number
National Heart, Lung, and Blood Institute Family Blood Pressure Program	5R00-HL116786-05, 5R01-HL-141404-06, F31-HL170534-01
National Heart, Lung, and Blood Institute Family Blood Pressure Program

Keywords

arteries
atherosclerosis
blood platelets
cause of death
thrombin

ASJC Scopus subject areas

Cardiology and Cardiovascular Medicine

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1161/ATVBAHA.124.322068

Cite this

Wadding-Lee, C. A., Jay, M., Shearer, S. M., Benson, T. W., Spuzzillo, A., Howatt, D. A., Thompson, J., Tourdot, B. E., Daugherty, A., Mackman, N., & Owens, A. P. (2025). Attenuation of Atherosclerosis with PAR4 Deficiency: A Potential Role of Hematopoietically Expressed PAR4 in Atherosclerosis - Brief Report. Arteriosclerosis, Thrombosis, and Vascular Biology, 45(6), 901-909. https://doi.org/10.1161/ATVBAHA.124.322068

@article{4c2a3ce2bd544dac8984db83643586b0,

title = "Attenuation of Atherosclerosis with PAR4 Deficiency: A Potential Role of Hematopoietically Expressed PAR4 in Atherosclerosis - Brief Report",

abstract = "BACKGROUND: Cardiovascular disease is a significant burden globally and, despite current therapeutics, remains the leading cause of death. PAR (protease-activated receptor) 4 is a receptor highly expressed by hematopoietic cells, strongly activated by thrombin, and plays a vital role in platelet activation and aggregation. However, the role of PAR4 in atherothrombotic disease remains understudied. METHODS: Mice on a low-density lipoprotein receptor-deficient (Ldlr-/-) background were bred with Par4-deficient (Par4-/-) mice to create Ldlr-/-/Par4+/+ and Ldlr-/-/Par4-/- cousin lines. Mice were fed high-fat (42\%) and high-cholesterol (0.2\%) Western diet for 12 weeks for all studies. Bone marrow transplant studies were conducted by irradiating Ldlr-/-/Par4+/+ and Ldlr-/-/Par4-/- mice with 550 rads (2×, 4 hours apart) and then repopulated with Par4+/+ or Par4-/- bone marrow. To determine whether the effects of thrombin were mediated solely by PAR4, the thrombin inhibitor dabigatran was added to the Western diet. RESULTS: We observed higher abundance of PAR4 in arteries with atherosclerosis in mouse and human lesions versus healthy controls. Using a global deletion of PAR4, we observed an attenuation in atherosclerosis versus Par4+/+ mice. Bone marrow transplant studies demonstrated these effects were due to hematopoietic cells. When observing whether PAR4 activation via thrombin contributes to atherosclerotic development, Ldl-/-/Par4-/- mice given dabigatran did not further decrease their atherosclerotic burden. Differences between apoE-deficient (apoE-/-) and Ldl-/- platelets were assessed for changes in reactivity. PAR4 appeared to be acting independent of PAR1, as there were no changes with the addition of dabigatran to Par4-/- mice. apoE-/- platelets were hyperreactive compared with Ldlr-/- platelets. CONCLUSIONS: We conclude that hematopoietic-derived PAR4 plays a vital role in the development and progression of atherosclerosis. More specifically, we observe thrombin-activated PAR4 contributes to the progression. Specifically, targeting of PAR4 may be a potential therapeutic target for cardiovascular disease.",

keywords = "arteries, atherosclerosis, blood platelets, cause of death, thrombin",

author = "Wadding-Lee, \{Caris A.\} and Megan Jay and Shearer, \{Shannon M.\} and Benson, \{Tyler W.\} and Anthony Spuzzillo and Howatt, \{Deborah A.\} and Joel Thompson and Tourdot, \{Benjamin E.\} and Alan Daugherty and Nigel Mackman and Owens, \{A. Phillip\}",

note = "Publisher Copyright: {\textcopyright} 2025 American Heart Association, Inc.",

year = "2025",

month = jun,

day = "1",

doi = "10.1161/ATVBAHA.124.322068",

language = "English",

volume = "45",

pages = "901--909",

number = "6",

}

Wadding-Lee, CA, Jay, M, Shearer, SM, Benson, TW, Spuzzillo, A, Howatt, DA, Thompson, J, Tourdot, BE, Daugherty, A, Mackman, N & Owens, AP 2025, 'Attenuation of Atherosclerosis with PAR4 Deficiency: A Potential Role of Hematopoietically Expressed PAR4 in Atherosclerosis - Brief Report', Arteriosclerosis, Thrombosis, and Vascular Biology, vol. 45, no. 6, pp. 901-909. https://doi.org/10.1161/ATVBAHA.124.322068

TY - JOUR

T1 - Attenuation of Atherosclerosis with PAR4 Deficiency

T2 - A Potential Role of Hematopoietically Expressed PAR4 in Atherosclerosis - Brief Report

AU - Wadding-Lee, Caris A.

AU - Jay, Megan

AU - Shearer, Shannon M.

AU - Benson, Tyler W.

AU - Spuzzillo, Anthony

AU - Howatt, Deborah A.

AU - Thompson, Joel

AU - Tourdot, Benjamin E.

AU - Daugherty, Alan

AU - Mackman, Nigel

AU - Owens, A. Phillip

PY - 2025/6/1

Y1 - 2025/6/1

N2 - BACKGROUND: Cardiovascular disease is a significant burden globally and, despite current therapeutics, remains the leading cause of death. PAR (protease-activated receptor) 4 is a receptor highly expressed by hematopoietic cells, strongly activated by thrombin, and plays a vital role in platelet activation and aggregation. However, the role of PAR4 in atherothrombotic disease remains understudied. METHODS: Mice on a low-density lipoprotein receptor-deficient (Ldlr-/-) background were bred with Par4-deficient (Par4-/-) mice to create Ldlr-/-/Par4+/+ and Ldlr-/-/Par4-/- cousin lines. Mice were fed high-fat (42%) and high-cholesterol (0.2%) Western diet for 12 weeks for all studies. Bone marrow transplant studies were conducted by irradiating Ldlr-/-/Par4+/+ and Ldlr-/-/Par4-/- mice with 550 rads (2×, 4 hours apart) and then repopulated with Par4+/+ or Par4-/- bone marrow. To determine whether the effects of thrombin were mediated solely by PAR4, the thrombin inhibitor dabigatran was added to the Western diet. RESULTS: We observed higher abundance of PAR4 in arteries with atherosclerosis in mouse and human lesions versus healthy controls. Using a global deletion of PAR4, we observed an attenuation in atherosclerosis versus Par4+/+ mice. Bone marrow transplant studies demonstrated these effects were due to hematopoietic cells. When observing whether PAR4 activation via thrombin contributes to atherosclerotic development, Ldl-/-/Par4-/- mice given dabigatran did not further decrease their atherosclerotic burden. Differences between apoE-deficient (apoE-/-) and Ldl-/- platelets were assessed for changes in reactivity. PAR4 appeared to be acting independent of PAR1, as there were no changes with the addition of dabigatran to Par4-/- mice. apoE-/- platelets were hyperreactive compared with Ldlr-/- platelets. CONCLUSIONS: We conclude that hematopoietic-derived PAR4 plays a vital role in the development and progression of atherosclerosis. More specifically, we observe thrombin-activated PAR4 contributes to the progression. Specifically, targeting of PAR4 may be a potential therapeutic target for cardiovascular disease.

AB - BACKGROUND: Cardiovascular disease is a significant burden globally and, despite current therapeutics, remains the leading cause of death. PAR (protease-activated receptor) 4 is a receptor highly expressed by hematopoietic cells, strongly activated by thrombin, and plays a vital role in platelet activation and aggregation. However, the role of PAR4 in atherothrombotic disease remains understudied. METHODS: Mice on a low-density lipoprotein receptor-deficient (Ldlr-/-) background were bred with Par4-deficient (Par4-/-) mice to create Ldlr-/-/Par4+/+ and Ldlr-/-/Par4-/- cousin lines. Mice were fed high-fat (42%) and high-cholesterol (0.2%) Western diet for 12 weeks for all studies. Bone marrow transplant studies were conducted by irradiating Ldlr-/-/Par4+/+ and Ldlr-/-/Par4-/- mice with 550 rads (2×, 4 hours apart) and then repopulated with Par4+/+ or Par4-/- bone marrow. To determine whether the effects of thrombin were mediated solely by PAR4, the thrombin inhibitor dabigatran was added to the Western diet. RESULTS: We observed higher abundance of PAR4 in arteries with atherosclerosis in mouse and human lesions versus healthy controls. Using a global deletion of PAR4, we observed an attenuation in atherosclerosis versus Par4+/+ mice. Bone marrow transplant studies demonstrated these effects were due to hematopoietic cells. When observing whether PAR4 activation via thrombin contributes to atherosclerotic development, Ldl-/-/Par4-/- mice given dabigatran did not further decrease their atherosclerotic burden. Differences between apoE-deficient (apoE-/-) and Ldl-/- platelets were assessed for changes in reactivity. PAR4 appeared to be acting independent of PAR1, as there were no changes with the addition of dabigatran to Par4-/- mice. apoE-/- platelets were hyperreactive compared with Ldlr-/- platelets. CONCLUSIONS: We conclude that hematopoietic-derived PAR4 plays a vital role in the development and progression of atherosclerosis. More specifically, we observe thrombin-activated PAR4 contributes to the progression. Specifically, targeting of PAR4 may be a potential therapeutic target for cardiovascular disease.

KW - arteries

KW - atherosclerosis

KW - blood platelets

KW - cause of death

KW - thrombin

UR - http://www.scopus.com/inward/record.url?scp=105003867805&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=105003867805&partnerID=8YFLogxK

U2 - 10.1161/ATVBAHA.124.322068

DO - 10.1161/ATVBAHA.124.322068

M3 - Article

C2 - 40270259

AN - SCOPUS:105003867805

SN - 1079-5642

VL - 45

SP - 901

EP - 909

JO - Arteriosclerosis, Thrombosis, and Vascular Biology

JF - Arteriosclerosis, Thrombosis, and Vascular Biology

IS - 6

ER -

Attenuation of Atherosclerosis with PAR4 Deficiency: A Potential Role of Hematopoietically Expressed PAR4 in Atherosclerosis - Brief Report

Abstract

Bibliographical note

Funding

Keywords

ASJC Scopus subject areas

UN SDGs

Access to Document

Other files and links

Fingerprint

Cite this