Increased hematopoiesis in long-term bone marrow cultures and reduced irradiation-induced pulmonary fibrosis in Von Willebrand factor homologous deletion recombinant mice

Abstract

Aim: We investigated whether homologous recombinant deletion of the endothelial cell-specific protein Von Willebrand factor (vWF) affected hematopoiesis in long-term bone marrow cultures, and irradiation induction of pulmonary fibrosis/organizing alveolitis.

Materials and methods: We established long-term bone marrow cultures from vWF(-/-) (C57BL/6 background) and vWF(+/+) littermate mice. Non-adherent cells removed weekly were tested for formation of multi-lineage hematopoietic stem cells forming colonies at 7 and 14 days in secondary semi-solid medium cultures. Irradiation fibrosis in the lungs of 20-Gy thoracic irradiated mice was quantitated and scored.

Results: Hematopoiesis was increased over 20 weeks in vWF(-/-) compared to vWF(+/+) cultures in production of non-adherent cells, and cells forming colonies at 7 or 14 days in secondary semi-solid medium culture. The irradiated lungs showed no increased fibrosis.

Conclusion: Absence of vWF increases hematopoiesis in long-term bone marrow cultures and has a protective effect in irradiated lungs.

Keywords: Von Willebrand factor; continuous marrow culture; longevity of hematopoiesis.