The profibrotic effects of chronic microaspiration of bile acids on lungs of rats at different stages.

This study aimed to explore the profibrotic effects of chronic microaspiration of two major bile acids, including chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA), on lungs of rats at different stages, as well as the underlying mechanisms in vivo. A rat model was induced by weekly intratracheal instillation of DCA and CDCA. Our results showed that chronic microaspiration of bile acids resulted in alveolar structure disorder, and inflammatory cells infiltration in the pulmonary interstitium at the early stage. Subsequently, numerous fibroblasts were proliferated, and collagen deposition was profoundly increased over the interstitium of the airways and vessels. Compared with control group, the expression of α-smooth muscle actin, type I collagen, hydroxyproline, transforming growth factor-ß1 (TGF-ß1), and matrix metalloproteinase-9 in the lung tissues were remarkably elevated at the 2nd week, reached the highest level at the 6th week, and maintained high at the 8th week in both DCA- and CDCA-treated groups (P < 0.05). Furthermore, chronic microaspiration of bile acids led to higher levels of glutathione and malondialdehyde, while lower level of superoxide dismutase in lung tissues compared with controls (P < 0.05), thereby resulting in the oxidant/antioxidant enzyme imbalance in the formation of fibrosis. In addition, we also found a consistent growth in the expression of farnesoid X receptor (FXR) in both DCA- and CDCA-treated groups. Our findings suggested that chronic microaspiration of bile acids could initiate the process of pulmonary fibrosis from the early phase and promote its progression in a time-dependent manner, which likely involved the TGF-ß1, oxidative stress, and FXR-related pathways.

Tobacco smoking aggravates airway inflammation by upregulating endothelin-2 and activating the c-Jun amino terminal kinase pathway in asthma.

BACKGROUND: Asthma is closely associated with tobacco smoking (TS) and is more difficult to effectively treat after exposure to TS. OBJECTIVE: To observe the effects of TS on the expression of endothelin-2 (ET-2) and airway inflammation in asthmatic rats and to explore the related mechanisms. METHODS: We established an animal model of asthma with ovalbumin (OVA)/Al(OH)3 and subjected different animal groups to TS and/or dexamethasone/bosentan. The differences in the inflammatory cell infiltration, the pathological changes to the bronchial wall and the bronchial smooth muscle thickness, and the expression of ET-2, c-Jun amino terminal kinase (JNK1/2), malondialdehyde (MDA), and glutathione peroxidase (GSH) in the lung tissue and of interleukin (IL)-7 in bronchoalveolar lavage fluid (BALF) were assessed. RESULTS: Exposure to TS or OVA caused an obvious increase in the inflammatory cells in the BALF over what was observed in the control group. In asthma models, the expression of ET-1, JNK1/2, MDA, and GSH in the lung tissues, as well as that of IL-17 in the BALF, was increased. After treatment with dexamethasone/bosentan, the expression of IL-17, JNK1/2, MDA, and GSH decreased compared to the smoking group; airway inflammation and the staining intensity in the lung tissue were also reduced. CONCLUSION: TS exposure can clearly exacerbate airway inflammation in asthmatic rats, while bosentan can alleviate airway inflammation through regulation of the ET-2/JNK1/2 signalling pathway.

Downregulation of BarH-like homeobox 2 promotes cell proliferation, migration and aerobic glycolysis through Wnt/ß-catenin signaling, and predicts a poor prognosis in non-small cell lung carcinoma.

BACKGROUND: Human BarH-like homeobox 2 (Barx2), a homeodomain factor of the Bar family, plays a critical role in cell adhesion and cytoskeleton remodeling, and has been reported in an increasing array of tumor types except non-small cell lung carcinoma (NSCLC). The purpose of the current study was to characterize the expression of Barx2 and assess the clinical significance of Barx2 in NSCLC. METHODS: Quantitative real-time polymerase chain reaction, immunohistochemistry and western blot analysis were used to examine mRNA and protein expression, respectively. The relationships between Barx2 expression and clinicopathological variables were analyzed. Cell Counting Kit-8 and plate colony formation assay were used to detect cell proliferation. Transwell assay was used to examine cell migration ability. Glucose uptake, lactate, adenosine triphosphate, and lactate dehydrogenase assays were used to detect aerobic glycolysis. RESULTS: Barx2 is downregulated in NSCLC tissues compared with para-carcinoma. Furthermore, Barx2 expression shows a negative correlation with advanced TNM stage and a high level of Ki-67. Survival analysis reveals that Barx2 level is an independent prognostic factor for NSCLC patients. The Barx2 (low) Ki-67 (high) group had the worst prognosis. Furthermore, the data indicate that downregulation of Barx2 expression promotes cell proliferation, migration, and aerobic glycolysis, including increased lactate dehydrogenase activity, glucose utilization, lactate production, and decreased intracellular adenosine triphospahte level. Furthermore, Barx2 acts as a negative regulator of the canonical Wnt/ß-catenin pathway. Reactivation of Wnt/ß-catenin pathway by LiCl can reverse the inhibiting effect of Barx2. CONCLUSIONS: These findings reveal that Barx2 serving as a tumor suppressor gene could decrease cell proliferation, migration, and aerobic glycolysis through inhibiting the Wnt/ß-catenin signaling pathway, and predicts a good prognosis in NSCLC.

[Estrogen shortens the latent period of inducing asthma and promotes airway inflammation].

Objective To investigate the effect of estrogen on the latent period of inducing asthma and airway inflammation in mice with asthma. Methods Forty male BALB/c mice were randomly divided into normal control group, OVA-induced asthma group, 400 µg/kg estradiol treatment group, 400 µg/kg estradiol combined with 7 mg/kg tamoxifen group, with 10 mice in each group. The OVA-induced asthma group, estradiol treatment group, and estradiol combined with tamoxifen group were sensitized and challenged by OVA; the normal control group was treated with normal saline instead. The estradiol treatment group and estradiol combined with tamoxifen group were given intraperitoneal injection of 400 µg/kg estradiol 4 hours before each challenge, and the latter was given additionally intraperitoneal injection of 7 mg/kg tamoxifen at 30 minutes before the injection of estradiol; the normal control group and OVA-induced asthma group were injected with normal saline as controls. The latent period of inducing asthma of all the mice was determined 24 hours after the final OVA challenge. Bronchoalveolar lavage fluid (BALF) was collected for counting total leukocyte cells and the percentages of eosinophils and lymphocytes. The concentrations of interleukin 4 (IL-4) and IL-13 in BALF were detected by ELISA. The pathologic change of lung tissues was examined by HE staining. Results Compared with the normal control group, the latent period of inducing asthma were shortened in the OVA-induced asthma group, estradiol treatment group, and estradiol combined with tamoxifen group; compared with the OVA-induced asthma group and estradiol combined with tamoxifen group, the latent period of inducing asthma of the estradiol treatment group were shortened; there was no significant difference in the latent period between the OVA-induced asthma group and the estradiol combined with tamoxifen group. Compared with the normal control group, the levels of IL-4 and IL-13 increased in the OVA-induced asthma group, estradiol treatment group, and estradiol combined with tamoxifen group; compared with the OVA-induced asthma group and estradiol combined with tamoxifen group, the levels of IL-4 and IL-13 increased in the estradiol treatment group; there was also no significant difference between the OVA-induced asthma group and the estradiol combined with tamoxifen group. Compared with the normal control group, the total leukocytes and the percentages of eosinophils and lymphocytes in BALF were raised in the OVA-induced asthma group, estradiol treatment group, and estradiol combined with tamoxifen group; compared with OVA-induced asthma group and estradiol combined with tamoxifen group, the total leukocytes and the percentage of eosinophils and lymphocytes of BALF were elevated in the estradiol treatment group; there was no significant difference between the OVA-induced asthma group and the estradiol combined with tamoxifen group. There was no infiltration of inflammatory cells in bronchial walls or airway mucosal edema in the normal control group. There were infiltration of inflammatory cells in bronchial walls and airway mucosal edema in the OVA-induced asthma group and estradiol combined with tamoxifen group, in addition, the estradiol treatment group was more serious than the two groups in these pathologic changes. Conclusion Estrogen can shorten the latent period of inducing asthma, promote the airway inflammatory cell infiltration and upgrade the expressions of IL-4 and IL-13.