OC 58.4 - Ibrutinib inhibits BMX-dependent endothelial VCAM-1 expression in vitro and pro-atherosclerotic endothelial activation and platelet adhesion in vivo

Tuesday, July 12, 2022

11:30 AM – 11:45 AM

Location: ExCel Center, ICC Capital Suite Room 17

Presentation Format: In-Person

Presenting Author(s)

Tia C.L. Kohs

PhD Candidate
Oregon Health & Science University
Portland, Oregon, United States

Co-Author(s)

SO

Sven R. Olson

Assistant Professor of Medicine
Oregon Health & Science University
Portland, Oregon, United States
KJ

Kelley R. Jordan

Senior Research Assistant
Oregon Health & Science University
Portland, Oregon, United States
TZ

Tony J. Zheng

MD/PhD Candidate
Oregon Health & Science University
Portland, Oregon, United States
AX

Aris Xie

Senior Research Associate
Oregon Health & Science University
Portland, Oregon, United States
JH

James Hodovan

Echo Technologist
Oregon Health & Science University
Portland, Oregon, United States
MM

Matthew Muller

Research Associate
Oregon Health & Science University
Portland, Oregon, United States
CM

Carrie McArthur

Senior Research Assistant
Oregon Health & Science University
Portland, Oregon, United States
JJ

Jennifer Johnson

Veterinary Research Health Technician 3
Oregon Health & Science University
Portland, Oregon, United States
BS

Bárbara B. Sousa

PhD Candidate
Instituto de Medicina Molecular João Lobo Antunes
Lisboa, Lisboa, Portugal
MW

Michael Wallisch

Principal Scientist
Aronora, Inc.
Portland, Oregon, United States
PK

Paul Kievit

Assistant Professor
Oregon Health & Science University
Portland, Oregon, United States
Joseph E. Aslan, PhD

Associate Professor
Oregon Health & Science University
Portland, Oregon, United States
JS

João D. Seixas

Senior Researcher
Instituto de Medicina Molecular João Lobo Antunes
Lisboa, Lisboa, Portugal
GB

Gonçalo J. Bernardes

Director of Chemical Biology and Pharmaceutical Biotechnology Unit
Instituto de Medicina Molecular João Lobo Antunes,
Lisboa, Lisboa, Portugal
MH

Monica T. Hinds

Assistant Dean of Student Affairs and Professor of Biomedical Engineering
Oregon Health & Science University
Portland, Oregon, United States
JL

Jonathan R. Lindner

Professor of Medicine
Oregon Health & Science University
Portland, Oregon, United States
OM

Owen J.T. McCarty, PhD, FAHA

Chair and Professor of Biomedical Engineering
Oregon Health & Science University
Portland, Oregon, United States
CP

Cristina Puy

Research instructor
Oregon Health & Science University
Portland, Oregon, United States
JS

Joseph J. Shatzel

Assistant Professor
Oregon Health & Science University
Portland, Oregon, United States

Background: Inflammatory activation of the vascular endothelium leads to the overexpression of adhesion molecules, including vascular cell adhesion molecule-1 (VCAM-1), contributing to the pro-thrombotic state underpinning atherogenesis. Although TEC family kinases (TFKs) mediate inflammatory cell and platelet activation, their contribution to vascular endothelial activation remain unclear.

Aims: Examine the role of TFK member, BMX, in endothelial cell (EC) activation in vitro and in atherosclerosis-prone carotid arteries of obese nonhuman primates (NHPs) in vivo.

Methods: Human aortic ECs (HAECs) were stimulated with vascular endothelial growth factors (VEGF)-A for 6 hours. BMX phosphorylation and VCAM-1 expression were measured by Western blot. To advance toward in vivo testing, two obese NHPs on a high-fat diet were administered the TFK inhibitor, ibrutinib orally daily for 7 days at 10 mg·kg−1·day−1 and studied at baseline, and days 1 and 7 after drug administration. We measured platelet activation and aggregation in primate samples in response to glycoprotein VI-agonist, cross-linked collagen-related peptide (CRP-XL). Contrast-enhanced ultrasound molecular imaging was used to measure platelet GPIbα and endothelial VCAM-1 expression at the carotid bifurcation in obese NHPs during treatment.

Results: VEGF-A increased VCAM-1 expression and induced phosphorylation of BMX in HAECs. Ibrutinib or BMX inhibitors eliminated the ability of VEGF-A to stimulate VCAM-1 expression in HAECs. In a NHP model of early atherosclerosis, platelet aggregation and activation in response to CRP-XL was abrogated following treatment with ibrutinib. Ibrutinib decreased the signal for both endothelial VCAM-1 and platelet GPIbα compare to baseline, in vivo.

Conclusion(s): Our studies demonstrate that VEGF-A signals through BMX to induce VCAM-1 expression and that VCAM-1 expression in HAECs is sensitive to ibrutinib. Treatment with ibrutinib decreased the markers of platelet deposition and endothelial cell activation in vivo. These findings suggest that TFKs may contribute to the pathogenesis of atherosclerosis and could represent a novel therapeutic target.