Objective To investigate the effects and mechanisms of lactic acid bacteria on MAPK signaling in immune response of dust mite sensitized mice. Methods Forty C57BL/6 mice in Group M, P and L, were sensitized and challenged with mite extract while then the animals in Group N were treated with saline as control. The mice in Group L and P were fed with Lactococcus lactis or Lactobacillus respectively.Three days after the last challenge, all mice were sacrificed for lung pathological examination. IL-10 level in culture supernatant of splenocytes stimulated with mite extract was detected by ELISA. The expression of IL-4/ IFN-γon CD3 +CD4 + cells was detected by flow cytometry. Western blot were performed for detection of MAPK signaling ( P38, ERK, and JNK) from mice’s spleen cells stimulated with mite extract. Results The mice fed with Lactococcus lactis ( Group L) had lower rate of eosinophilic airway inflammation and higher level of IL-10 in the culture supernatant of splenocytes than Group P. Meanwhile, the number of CD4 + T cell with IL-4 expression was decreased revealed by the analysis of flow cytometry. P38 signaling inspleen cells was activated in the mice of Group M, similarly in the mice of Group P, but not of Group L.Conclusion Oral treatment of Lactococcus lactis can induce an immune tolerance in response to mite by up-regulating the level of Tr cells secreting IL-10, thus inhibiting activation of P38 signaling.
Objective To explore the effects of bone marrow mesenchymal stem cells ( BMMSCs) on pulmonary fibroblasts of patients with nonspecific interstitial pneumonitis ( NSIP) , and investigate the therapeutic mechanism of BMMSCs for interstitial pulmonary fibrosis. Methods Human BMMSCs, human pulmonry fibroblasts ( HPFs) from NSIP patients, and normal HPFs were primary cultured in vitro. Then HPFs fromNSIP patients were co-cultured with BMMSCs or normal HPFs using Transwell co-culture system. After 24 hours, levels of transforming growth factor β1 (TGF-β1) and interferon inducible protein 10 ( IP-10) in culture supernatants were detected by ELISA method. Meanwhile, interleukin-6 ( IL-6) , IL-8, and monocyte chemotactic protein-1 ( MCP-1) in co-culture supernatants were detected by liquid chip. After co-cultured for 48 hours, total protein of HPFs was extracted and the expression level of alpha smooth muscle actin ( α-SMA) secreted by HPFs were detected by Western blot.Results HPFs from NSIP patients secreted higher level of IL-6, IL-8, and MCP-1 than normal HPFs, and secreted high level of α-SMA. In the Transwell co-culture system, human BMMSCs significantly reduced the levels of IL-6, IL-8, and MCP-1 secreted from HPFs of NSIP patients, and reduced the high expression of α-SMA in HPFs of NSIP patients. Conclusion Human BMMSCs can significantly reduce the secretion of IL-6, IL-8, MCP-1, and the expression of α-SMA in HPFs from NSIP patients.