PB1266 - Maphosphamide, a cyclophosphamide analog, increases proinflammatory and permeability responses on endothelial cells in vitro

Tuesday, July 12, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Julia Martinez-Sanchez, MS

PhD student
Josep Carreras Leukaemia Research Institute, Hospital Clínic de Barcelona, Universitat de Barcelona, Barcelona, Spain.
Barcelona, Catalonia, Spain

Co-Author(s)

RP

Roger Pascual-Diaz

Medicine student
Hematopathology, Department of Pathology, Centre de Diagnòstic Biomèdic (CDB), Hospital Clínic de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain.
Barcelona, Catalonia, Spain
MP

Marta Palomo

PhD
Josep Carreras Leukaemia Research Institute, Hospital Clínic de Barcelona, Universitat de Barcelona, Barcelona, Spain.
Barcelona, Catalonia, Spain
Ana Belén Moreno-Castaño, MD

Medical Doctor
Hemostasis and Erythropathology Laboratory, Hematopathology, Department of Pathology, Centre de Diagnòstic Biomèdic (CDB), Hospital Clínic de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain.
Barcelona, Catalonia, Spain
HV

Helena Ventosa-Capell

MD, PhD Student
Hematopathology, Department of Pathology, Centre de Diagnostic Biomedic (CDB), Hospital Clínic de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
Barcelona, Catalonia, Spain
MR

Montserrat Rovira

Medical Doctor
Hematology Department, Bone Marrow Transplantation Unit, Institut Clínic de Malalties Hemato-Oncològiques (ICMHO), Hospital Clínic, Barcelona, Spain.
Barcelona, Catalonia, Spain
GE

Gines Escolar

MD PhD Senior Consultant
Hemostasis and Erythropathology Laboratory, Hematopathology, Department of Pathology, Centre de Diagnòstic Biomèdic (CDB), Hospital Clínic de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain.
Barcelona, Catalonia, Spain
EC

Enric Carreras

Medical Doctor
Josep Carreras Leukaemia Research Institute, Hospital Clínic de Barcelona, Universitat de Barcelona, Barcelona, Spain.
Barcelona, Catalonia, Spain
Maribel Diaz-Ricart, PhD

Senior Researcher
Hospital Clinic, IDIBAPS, University of Barcelona, Spain
Barcelona, Catalonia, Spain

Background: Graft-versus-host disease (GVHD) remains a major complication of allogeneic hematopoietic cell transplantation (allo-HCT). Allo-HCT causes endothelial activation and damage. In addition, endothelial dysfunction plays a key role in the GVHD pathophysiology. The immunosuppressive drugs administered during allo-HCT exhibit a detrimental impact on the endothelium. Administration of post-transplant cyclophosphamide has significantly decreased GVHD incidence.

Aims: To evaluate the effect of maphosphamide (MPH), a cyclosphosphamide analog with direct activity, on endothelial cells in comparison to cyclosporine A (CSA), a standard immunosuppressant with known damaging effect on the endothelium.

Methods: Human microvascular endothelial cells (ECs) in culture were exposed (48h) to MPH (2µg/ml) and CSA (200ng/ml), to explore changes in markers of endothelial damage, such as: i) the adhesion receptor VCAM-1, ii) production of VWF, iii) the cell permeability protein VE-cadherin, and iv) activation of the inflammation-related protein p38 MAPK.

Results: Both MPH and CSA induced statistically significant increments in VCAM-1 expression in comparison to control cells (fold increases: 2.8±0.4 and 2.6±0.3, respectively, p< 0.01). While the production of VWF was enhanced in response to CSA (fold increase: 1.4±0.2, p< 0.05), it was reduced with MPH (0.8±0.1, p< 0.05). VE-cadherin expression decreased significantly in response to MPH (fold increase: 0.7±0.1, p< 0.01), whereas no effect was observed with CSA. Activation of p38 MAPK occurred in response to both compounds but it was higher and faster for CSA.

Conclusion(s): Our results demonstrate that maphosphamide exerted a proinflammatory effect on endothelial cells similar to the observed with cyclosporine A. The decreased expression of VE-cadherin with maphosphamide could indicate an increased endothelial permeability. Therefore, the cyclophosphamide analog is not exempt of an activating action on the endothelium. Further studies are needed to explore the mechanisms of cyclophosphamide in this setting.