Placenta‑derived mesenchymal stem cells ameliorate lipopolysaccharide‑induced inflammation in RAW264.7 cells and acute lung injury in rats

Acute lung injury (ALI) is a severe lung syndrome with high morbidity and mortality, due to its complex mechanism and lack of effective therapy. The use of placenta‑derived mesenchymal stem cells (pMSCs) has provided novel insight into treatment options of ALI. The effects of pMSCs on lipopolysaccharide (LPS)‑induced inflammation were studied using a co‑culture protocol with LPS‑stimulated RAW264.7 cells. An LPS‑induced ALI Sprague‑Dawley rat model was developed by intravenously injecting 7.5 mg/kg LPS, and intratracheal instillation of 1x105 pMSCs was performed after administration of LPS to investigate the therapeutic potential of these cells. pMSCs ameliorated LPS‑induced ALI, as suggested by downregulated pro‑inflammatory cytokine tumor necrosis factor‑α and increased anti‑inflammatory cytokine interleukin‑10 in both cell and animal models. Moreover, the protein and leukocyte cells in bronchoalveolar lavage fluid decreased at a rapid rate after treatment with pMSCs. Histopathology demonstrated that pMSCs alleviated the infiltration of inflammatory cells, pulmonary hyperemia and hemorrhage, and interstitial edema. In addition, pMSC reduced the LPS‑induced expression of C‑X‑C motif chemokine ligand 12 in RAW264.7 macrophages and in lung tissue of ALI rats. This demonstrated that pMSCs are therapeutically effective in LPS‑induced ALI.