FVIII production by human lung microvascular endothelial cells.
While extrahepatic factor VIII (FVIII) synthesis suffices for hemostasis, the extrahepatic production sites are not well defined. We therefore investigated the ability of the human lungs to produce FVIII. Lungs from heart-beating donors who were declined for transplantation were perfused and ventilated in an isolated reperfusion model for 2 hours. A progressive accumulation of FVIII and von Willebrand factor (VWF) was recorded in the perfusion medium in 3 of 4 experiments. By contrast, factor V, fibrinogen, and immunoglobulin G (IgG) levels remained constant during the perfusion period, indicating that the accumulation of FVIII and VWF was not due to diffusion from the intercellular medium into the vascular system. Purified human lung microvascular endothelial cells produced FVIII during at least 2 passages in vitro. Altogether, these data identify the lung endothelial cells as a FVIII production site in humans.
Jacquemin
Marc
M
Center for Molecular and Vascular Biology, University of Leuven, Belgium. jacquemin@med.kuleuven.be
Neyrinck
Arne
A
Hermanns
Maria Iris
MI
Lavend'homme
Renaud
R
Rega
Filip
F
Saint-Remy
Jean-Marie
JM
Peerlinck
Kathelijne
K
Van Raemdonck
Dirk
D
Kirkpatrick
Charles James
CJ
D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism; D005169:Factor VIII / Q000032:analysis / Q000096:biosynthesis*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008168:Lung / Q000098:blood supply* / Q000378:metabolism; D008833:Microcirculation; D011652:Pulmonary Circulation; D015424:Reperfusion; D014841:von Willebrand Factor / Q000032:analysis
D014841:von Willebrand Factor; D005169:Factor VIII