PB1281 - Non-parenchymal origin of alternatively spliced tissue factor in chronic liver disease

Tuesday, July 12, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Co-Author(s)

CL

Clayton S. Lewis, PhD

Postdoctoral Fellow
Division of Hematology/Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine
Cincinnati, Ohio, United States
KS

Kateryna Stone, BS

PhD Candidate
Division of Hematology/Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine
Cincinnati, Ohio, United States
DK

Damaris Kuhnell, MS

Research Associate
Department of Environmental & Public Health Sciences, University of Cincinnati College of Medicine
Cincinnati, Ohio, United States
SL

Scott M. Langevin, PhD, MHA, CT(ASCP)

Assistant Professor of Medicine
Department of Environmental & Public Health Sciences, University of Cincinnati College of Medicine
Cincinnati, Ohio, United States
AS

Alejandro Soto-Gutierrez, MD, PhD

Assistant Professor of Medicine
Department of Pathology, University of Pittsburgh Medical Center
Pittsburgh, Pennsylvania, United States
PV

Patrick Van Dreden

PhD clinical research manager
Clinical Research Department, Diagnostica Stago
Gennevilliers, Ile-de-France, France
James P. Luyendyk, PhD

Ph.D.
Michigan State University, College of Veterinary Medicine, Department of Pathobiology and Diagnostic Investigation
East Lansing, Michigan, United States

Presenting Author(s)

Vladimir Y. Bogdanov, PhD

Associate Professor of Medicine
College of Medicine, University of Cincinnati
Cincinnati, Ohio, United States

Background: Expression of alternatively spliced Tissue Factor (asTF), an integrin activator, is low in the healthy liver. Recently, we reported that plasma asTF is elevated in patients with chronic liver disease (CLD).

Aims: To explore the potential cellular sources and mechanistic underpinnings of asTF’s upregulation in CLD.

Methods: Extracellular microvesicles (MVs) and asTF protein were measured in CLD plasma. MVs were concentrated by ultracentrifugation and characterized using antibody selection and CountBright™ Plus Absolute Counting Beads. Immunohistochemistry was used to detect asTF protein in livers of mice with experimental hepatic fibrosis (carbon tetrachloride (CCl4) or high trans-fat diet (HTFD)), and in human liver (healthy and cirrhotic). asTF mRNA and protein expression were studied in human cell lines HepG2 and Huh7 (hepatocytes), LX-2 (stellate cells), and TMNK1 (liver sinusoidal endothelium).

Results: Plasma asTF levels associated strongly with those of CD31+/CD41- MVs; significance rose with increasing CLD severity. Compared to control mice, asTF staining was increased along the endothelium lining of central veins of both CCl4-challenged and HTFD-fed mice (Figure 1). asTF co-localized with CD31 in the human liver with minimal expression in healthy tissue, high expression in low-stage fibrosis, and moderate expression in late-stage fibrosis (Figure 2). Constitutive asTF expression was extremely low in HepG2 and Huh7 cells compared to that observed in LX-2 and TMNK1 cells. Treatment of TMNK1 cells with TNFα (20 ng/mL) induced asTF protein, which persisted beyond 6 hrs post-induction. Notably, TNFα treatment of TMNK1 cells increased the release of both asTF protein and MVs. Interestingly, treatment of LX-2 cells with angiotensin II (10 nM) transiently induced asTF expression.

Conclusion(s): Non-parenchymal cells, particularly endothelium, display inducible asTF expression that may contribute to increased asTF in CLD. The precise role of asTF in CLD progression requires further study because asTF’s impact on integrin signaling may comprise a therapeutic target.