Objective      To investigate the expression and function of receptor interacting protein 140 (RIP140) in alveolar macrophages of rats with septic acute lung injury.       Methods      A total of 36 male Sprague-Dawley rats were randomly divided into a normal control group

a sham control group

and cecal ligation and puncture (CLP) 3

6

12 and 24 h groups. Septic acute lung injury was induced by CLP operation. HE staining was used to observe the pathological changes in lung tissues. The expression and distribution of RIP140 in the lung tissues of the rats with septic acute lung injury were detected by immunohistochemistry. The RIP140 protein expression in the alveolar macrophages was measured by Western blotting. The location of RIP140 in the alveolar macrophages was analyzed by immunofluorescence technique. The mRNA levels of interleukin (IL)-1β

tumor necrosis factor (TNF)-α

and IL-6 were detected by RT-qPCR.       Results      Compared with the 2 control groups

obvious lung injury was observed in the CLP groups. RIP140 was mainly expressed in the inflammatory infiltration cells of pulmonary mesenchyme

and RIP140-expressing cells were increased. On 6 h after CLP operation

the level of RIP140 protein was significantly elevated (P0.05) in the alveolar macrophages and maintained at a high level from 12 h to 24 h. RIP140 protein was mainly localized in the nuclei of the alveolar macrophages in the rats with septic acute lung injury. The IL-1β

TNF-α and IL-6 mRNA levels in the alveolar macrophages were increased (P0.05) on 3 h after CLP operation and maintained at a high level from 12 h to 24 h. However

down-regulation of RIP140 could significantly inhibit the expressions of IL-1β

TNF-α and IL-6 mRNA in the alveolar macrophages.       Conclusion      In septic acute lung injury

the elevated expression of RIP140 in the alveolar macrophages can enhance the inflammatory response

and RIP140 may be involved in the inflammatory response of septic acute lung injury.