VEGF promotes malaria-associated acute lung injury in mice

© 2010 Epiphanio et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The spectrum of the clinical presentation and severity of malaria infections is broad, ranging from uncomplicated febrile illness to severe forms of disease such as cerebral malaria (CM), acute lung injury (ALI), acute respiratory distress syndrome (ARDS), pregnancy-associated malaria (PAM) or severe anemia (SA). Rodent models that mimic human CM, PAM and SA syndromes have been established. Here, we show that DBA/2 mice infected with P. berghei ANKA constitute a new model for malaria-associated ALI. Up to 60% of the mice showed dyspnea, airway obstruction and hypoxemia and died between days 7 and 12 post-infection. The most common pathological findings were pleural effusion, pulmonary hemorrhage and edema, consistent with increased lung vessel permeability, while the blood-brain barrier was intact. Malaria-associated ALI correlated with high levels of circulating VEGF, produced de novo in the spleen, and its blockage led to protection of mice from this syndrome. In addition, either splenectomization or administration of the anti-inflammatory molecule carbon monoxide led to a significant reduction in the levels of sera VEGF and to protection from ALI. The similarities between the physiopathological lesions described here and the ones occurring in humans, as well as the demonstration that VEGF is a critical host factor in the onset of malaria-associated ALI in mice, not only offers important mechanistic insights into the processes underlying the pathology related with malaria but may also pave the way for interventional studies.This work was partially supported by Fundação para a Ciência e a Tecnologia (FCT) (POCTI/SAU-IMI/57946/2004 to M.M.M.), the European Science Foundation (EURYI 2004 to M.M.M.) and the Gemi Fund (to M.M.M.). S.E., M.G.C., and A.C.P. were supported by FCT fellowships (SFRH/BPD/31598/2006, SFRH/BD/ 10034/2002 and SFRH/BPD/31598/2006, respectively). M.M.M. is a fellow of the EMBO Young Investigator Program and is a Howard Hughes Medical Institute International Scholar