RESUMO
BACKGROUND AIMS: Stem cells may be a promising therapy for acute respiratory distress syndrome. Recent in vivo and in vitro studies suggested that the mesenchymal stromal cells (MSCs) have anti-oxidative stress properties. We hypothesized that intravenous injection of bone marrow-derived mesenchymal stem cells (MSCs) could attenuate Escherichia coli-induced acute lung injury (ALI) in mice by controlling the oxidative stress status. METHODS: Eighty mice were randomly divided into four groups: group 1 (control group) received 25 µL of saline as a vehicle; group 2 contained E coli-induced ALI mice; group 3 included mice that received MSCs before induction of ALI; group 4 included mice that received MSCs after induction of ALI. Lung samples were isolated and assayed for oxidative stress variables and histopathologic analysis. Total anti-oxidant capacity was measured in broncho-alveolar lavage. RESULTS: Pre- and post-injury MSC injection increased survival, reduced pulmonary edema and attenuated lung injuries in ALI mice. Histologically, MSCs exhibited a considerable degree of preservation of the pulmonary alveolar architecture. An increase of anti-oxidant enzyme activities and a decrease of myeloperoxidase activity and malondialdehyde levels in the MSC recipient groups versus the ALI group were found. Furthermore, the total anti-oxidant capacity and reduced glutathione levels were significantly increased in MSCs recipient groups versus the ALI group. Weak +ve inducible nitric oxide synthase immuno-expression in groups that received MSCs was detected. Pre-injury MSC injection showed better effects than did post-injury MSC injection. CONCLUSIONS: Systemic bone marrow-derived MSC injection was effective in modulating the oxidative stress status in E coli-induced acute lung injury in mice.