OC 35.1 - Factor VIII regulates extracellular matrix proteins to stimulate angiogenesis and vessel stability

Monday, June 24, 2024

09:30 – 09:45 ICT

Room: 110 A-C

Co-Author(s)

Cristina Olgasi

Tenure-track Assistant Professor
University of Piemonte Orientale, Department Translational Medicine
Novara, Piemonte, Italy

Presenting Author(s)

Alessia Cucci, PhD

Post Doc
University of Piemonte Orientale, Department of Health Sciences
Novara, Piemonte, Italy

Co-Author(s)

IM

Ivan Molineris

Associate Professor
Università degli Studi di Torino, Torino, Italy
Turin, Piemonte, Italy
SA

Simone Assanelli

PhD student
Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
Novara, Piemonte, Italy
FA

Francesca Anselmi

Technician
Università degli Studi di Torino, Torino, Italy.
Turin, Piemonte, Italy
CB

Chiara Borsotti

Tenure-track Assistant Professor
Department of Health Sciences, University of Piemonte Orientale
Novara, Piemonte, Italy
CS

Chiara Sgromo

PhD student
Department of Health Sciences, University of Piemonte Orientale
Novara, Piemonte, Italy
AL

Andrea Lauria

Research Assistant Professor
University of Turin, Turin, Italy
Turin, Piemonte, Italy
SM

Simone Merlin

Associate Professor
Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
Novara, Piemonte, Italy
GW

Gillian E. Walker

Technologist
Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
Novara, Piemonte, Italy
SO

Salvatore Oliviero

Full professor
University of Turin, Turin, Italy
Turin, Piemonte, Italy
Antonia Follenzi, MD, PhD

Full Professor
University of Piemonte Orientale, Department of Health Sciences
Novara, Piemonte, Italy

Background: Hemophilia A (HA) is an X-linked bleeding condition resulting from mutations in the coagulation factor VIII (FVIII). Despite the primary clinical manifestations of the disease are spontaneous bleedings, there is limited understanding of the vascular stability status of HA patients. Moreover, little is known about the relationship between FVIII and endothelial function.

Aims: To investigate the FVIII role in maintaining EC function and homeostasis.

Methods: Blood Outgrowth ECs (BOECs) from HA patients and healthy donors were isolated. HA BOECs were transduced with a lentiviral vector (LV) carrying the B-domain deleted FVIII (LV-FVIII). The transcriptomic profile of healthy, HA and LV-FVIII HA BOECs was assessed by RNA-seq technology. Healthy ECs, HA ECs, LV-FVIII HA-ECs, were used to investigate the role of FVIII in ECs function by tubulogenesis, migration, and permeability assays both in vitro and in vivo in a mouse model of severe HA (NSG-HA) mice.

Results: HA BOECs showed alteration of vessel-formation, endothelial cell migration, and vessel permeability. This impaired phenotype was reverted by the re-introduction of FVIII gene or by acute treatment with recombinant FVIII. The endothelial function of FVIII was confirmed in vivo in NSG-HA mice which showed that an altered angiogenesis and vessel permeability could be corrected by exogenous FVIII. The transcriptomic profiles of BOECs revealed that FVIII regulates the expression of endothelial basement membrane and extracellular matrix genes. The exogenous expression of Nidogen2, identified as a FVIII regulated gene, restored the extracellular matrix integrity and EC function of HA ECs.

Conclusion(s): The reduced EC function can be explained by the downregulated genes identified in FVIII deficient HA BOECs. Altogether, these results suggest that FVIII is not only a coagulation factor but also an endothelial cell factor which promotes vessel stability by upregulating genes involved in extracellular matrix organization.