In
acute lung injury/
acute respiratory distress syndrome (ALI/ARDS), pathogenesis is associated with the regulation of macrophage-generated oxidative stress, and
nicotinamide adenine dinucleotide phosphate (
NADPH) oxidase (NOX)-derived
reactive oxygen species(ROS) are key to regulating oxidative stress. In the present study, we found that miR-19 inhibited the expression of p47phox in macrophages, resulting in the alleviation of the
lipopolysaccharides(LPS)-induced inflammatory response. In a mouse LPS-induced model of
lung injury, miR-19-deficient murine lung tissue was more susceptible to inflammatory responses and exhibited a higher infiltration rate, a higher number of inflammatory cells in the lungs, a higher level of inflammatory
cytokines in the Bronchoalveolar lavage fluid (BALF), and more severe pathological damage in lung tissues. Moreover, following stimulation with LPS, p47phox was expressed at lower levels in miR-19-deficient murine pulmonary inflammatory cells than in those in wild-type rats. In LPS-treated Raw264.7 macrophages, miR-19 mimics blocking the down-regulation of LPS-induced p47phox expression, the accumulation of ROS, and the release of inflammatory
cytokines. When
siRNA was used to interfere with p47phox expression following stimulation with LPS, a lower level of ROS-mediated inflammatory
cytokines were released. We found that the accumulation of ROS inhibited the LPS-induced release of inflammatory
cytokines, the upregulation of miR-19 and the down-regulation of LPS-induced p47phox expression. Finally, we constructed a p47phox
3'UTR luciferase reporter plasmid to provide direct confirmation that miR-19 targets p47phox expression. The results of this study indicate the presence of a mechanism by which miR-19 regulates oxidative stress in macrophages. These data also provide potential targets for studies aimed at developing
therapies for ARDS.