Activated Akt protects the lung from oxidant-induced injury and delays death of mice

Oxidant-induced injury to the lung causes extensive damage to lung epitheli al cells. Impaired protection and repair of the lung epithelium can result in death. The serine-threonine kinase Akt has been implicated in inhibiting cell death induced by different stimuli including growth factor withdrawal , cell cycle discordance, DNA damage, and loss of cell adhesion in differen t cell types. However, the in vivo relevance of this prosurvival pathway ha s not been explored. Here we show that a constitutively active form of Akt introduced intratracheally into the lungs of mice by adenovirus gene transf er techniques protects mice from hyperoxic pulmonary damage and delays deat h of mice. This is the first demonstration of the in vivo protective functi on of Akt in the context of oxidant-induced lung injury.