Objective To investigate the effects of IL-10 on lipopolysaccharide( LPS) -induced MyD88 /NF-κB signaling activation. Methods Ana-1 macrophages were divided into a LPS group and a LPS + IL-10 group. The cells and the culture supernatant were collected at 0, 0. 5, 1, and 2 hours respectively. The expression levels of NF-κB p65 and MyD88 in cytoplasm and nucleus were detected by Western blotting. The concentration of TNF-αin the culture supernatant was determined by ELISA. Results Through 0 to 2 hours, MyD88 expression increased significantly after LPS stimulation. The expression was attenuated by the pretreatment of IL-10, which returned to normal levels at 2 hours( 8. 8 ±0. 3 vs 21. 4 ±1. 8,P lt;0. 05) . IL-10 had no effect on total expression of NF-κB, but decreased nuclei / cytoplasm ratio of NF-κB p65 after LPS stimulation. The ratio was lower in the LPS + IL-10 group compared and the LPS group at 1 hour and 2 hour ( 1. 1 ±0. 1 vs 2. 4 ±0. 4, 0. 6 ±0. 7 vs 3. 1 ±0. 6, P lt; 0. 05) . Consequently, IL-10 pretreatment decreased TNF-α concentration after LPS stimulation at 1 hour and 2 hours [ ( 222. 5 ±33. 5) pg/mL vs ( 365. 2 ±22. 7) pg/mL, ( 212. 7 ±15. 9) pg/mL vs ( 566. 2 ±31. 5) pg/mL, P lt;0. 05] .Conclusion IL-10 attenuates inflammation via MyD88 /NF-κB signal pathway depression.
Objective To evaluate the effects of N-acetylcysteine ( NAC) on bleomycin-induced lung fibrosis in mice and to investigate the therapeutic mechanisms of NAC on lung fibrosis. Methods Forty-five KM female mice were randomly divided into 3 groups. The mice in the control group were administered with saline aerosol intratracheally. The mice in the fibrosis group were administered with bleomycin ( 3 mg/kg) dissolved in normal saline aerosol intratracheally. The mice in the NAC group were gastric perfused with NAC at a dose of 400 mg · kg- 1 · d - 1 after administering bleomycin aerosol intratracheally. All animals were sacrificed 28 days after the treatments. The left lung was fixed in 10% neutral formalin, then stained with hematoxylin eosin and Masson’s trichrome respectively for the pathological examination. The right lung was sampled and the content of hydroxyproline ( HYP) was assayed by alkaline hydrolysis method. The serum was collected and the concentrations of malondialdehyde ( MDA) and totalantioxidant capacity ( T-AOC) were measured by colorimetric method. The RNA and total tissue protein were extracted for the examination of NOX1 /2/4 by RT-PCR and Western blot respectively. Results NAC prevented lung fibrosis induced by bleomycin with significantly reducing lung collagen accumulation and the level of HYP in the NAC group ( P lt;0. 05) . The serum concentration of MDA were reduced and serum TAOC raised by treating NAC after intratracheal administration of bleomycin ( P lt;0. 05) . NOX1 /2/4 gene and protein expression were increased in the fibrosis group compared with the control group. NAC had no effect on the gene expression of NOX1/2 /4( P gt;0. 05) , but inhibitted the NOX4 protein expression in lung tissue significantly ( P lt; 0. 05) . Conclusion NAC inhibits the expression of NOX4 and prevents bleomycin-induced lung fibrosis in mice.
Objective To evaluate the effects of two different epidermal growth factor receptor tyrosine kinase inhibitors ( EGFR-TKIs) , Gefitinib and Erlotinib, on lung fibrosis induced by bleomycin.Methods Forty BALB/c female mice were randomly divided into four groups, ie. a control group( saline given orally and intratracheally) , a fibrosis group( saline given orally with bleomycin instillation) , a Gefitnib group( Gefitnib 20 mg/kg given orally with bleomycin instillation) , and an Erlotinib group ( Erlotinib25 mg/kg given orally with bleomycin instillation) . Bleomycin ( 3 mg/kg) was intratracheally instilled on the first day. Gefitinib or Erlotinib was given orally daily and normal saline as control. Then they were sacrificed by abdominal aortic bleeding 14 days after the bleomycin instillation. The left lung was stained with HE and Masson’s trichrome staining respectively for pathological examination. Total EGFR and phosphorylated EGFR were detected by immunohistochemistry. Hydroxyproline ( HYP) assay was performed in the right lung.Results Both Gefitinib and Erlotinib significantly reduced lung collagen accumulation and the content of HYP. Immunohistochemistry revealed that phosphorylation of EGFR in lung mesenchymal cells induced by bleomycin was inhibited. Furthermore, there was no difference between Gefitinib and Erlotinib in inhibiting lung fibrosis. Conclusion Our findings suggest that, in the preclinical setting, EGFR-TKIs may have aprotective effect on lung fibrosis induced by bleomycin.
Objective To compare three approaches of lipopolysaccharides ( LPS) administration for inducing acute lung injury ( ALI) in mice. Methods LPS ( 5 mg/kg) was intratracheally aerosol administered ( ITA group) , intratracheally instilled ( ITI group) , or intraperitoneally injected ( IPI group) to induce ALI in BLAB/ c mice. Evans Blue instead of LPS was intratracheally administered to observe the liquid distribution in the lungs. Two hours after LPS administration, the mice were sacrificed and the lungs were removed to determine wet-to-dry lung weight ratio ( W/D) , and the histological changes were evaluated by HE staining. Phosphorylation level of IκB-αand NF-κB p65 in lung tissue were investigated by Western blot. Transcription intensity of TNF-α and IL-1β mRNA in lung tissue were detected by real-time quantitative PCR. Results Evans Blue distributed more uniformly in the ITA group than the ITI group. The lung W/D ratio and histological changes score in three LPS administration groups were all significantly higher than the normal control group ( P lt;0. 01) , with the ITA group being the highest. The phosphorylation levels of IκB-αand NF-κB p65 were significantly higher in the ITA group than the ITI group ( P lt;0. 05) , and were significantly higher in the ITI group than the IPI group ( P lt; 0. 05) . Transcription intensity of TNF-αand IL-1βmRNA was significantly higher in the ITA group than the ITI group ( P lt;0. 05) , and were significantly higher in the ITI group than the IPI group ( P lt;0. 05) . Conclusion Being non-invasive and convenient,intratracheal LPS aerosol inhalation is an optimal method to induce ALI in mice because it induces more extensive and uniformly distributed injuries in lung.