Chronic airway remodeling is characterized by structural changes within the airway wall, including smooth muscle hypertrophy, submucosal fibrosis and epithelial shedding. Epithelial-to-mesenchymal transition (EMT) is a fundamental mechanism of organ fibrosis, which can be induced by TGF-b. In the in vitro study, we investigated whether 1-20 mM kaempferol inhibited lipopolysaccharide (LPS)-induced bronchial EMT in BEAS-2B cells. The in vivo study explored demoting effects of 10-20 mg/kg kaempferol on airway fibrosis in BALB/c mice sensitized with ovalbumin (OVA). LPS induced airway epithelial TGF-b1 signaling that promoted EMT with concurrent loss of E-cadherin and induction of a-smooth muscle actin (a-SMA). Nontoxic kaempferol significantly inhibited TGF-b-induced EMT process through reversing E-cadherin expression and retarding the induction of N-cadherin and a-SMA. Consistently, OVA inhalation resulted in a striking loss of epithelial morphology by displaying myofibroblast appearance, which led to bronchial fibrosis with submucosal accumulation of collagen fibers. Oral administration of kaempferol suppressed collagen deposition, epithelial excrescency and goblet hyperplasia observed in the lung of OVA-challenged mice. The specific inhibition of TGF-b entailed epithelial protease-activated receptor-1 (PAR-1) as with 20 mM kaempferol. The epithelial PAR-1 inhibition by SCH-79797 restored E-cadherin induction and deterred a-SMA induction, indicating that epithelial PAR-1 localization was responsible for resulting in airway EMT. These results demonstrate that dietary kaempferol alleviated fibrotic airway remodeling via bronchial EMT by modulating PAR1 activation. Therefore, kaempferol may be a potential therapeutic agent targeting asthmatic airway constriction.

BackgroundEotaxin proteins are a potential therapeutic target in treating the peribronchial eosinophilia associated with allergic airway diseases. Since inflammation is often associated with an increased generation of reactive oxygen species (ROS), oxidative stress is a mechanistically imperative factor in asthma. Astragalin (kaempferol-3-O-glucoside) is a flavonoid with anti-inflammatory activity and newly found in persimmon leaves and green tea seeds. This study elucidated that astragalin inhibited endotoxin-induced oxidative stress leading to eosinophilia and epithelial apoptosis in airways.MethodsAirway epithelial BEAS-2B cells were exposed to lipopolysaccharide (LPS) in the absence and presence of 1–20 μM astragalin. Western blot and immunocytochemical analyses were conducted to determine induction of target proteins. Cell and nuclear staining was also performed for ROS production and epithelial apoptosis.ResultsWhen airway epithelial cells were exposed to 2 μg/ml LPS, astragalin nontoxic at ≤20 μM suppressed cellular induction of Toll-like receptor 4 (TLR4) and ROS production enhanced by LPS. Both LPS and H2O2 induced epithelial eotaxin-1 expression, which was blocked by astragalin. LPS activated and induced PLCγ1, PKCβ2, and NADPH oxidase subunits of p22phox and p47phox in epithelial cells and such activation and induction were demoted by astragalin or TLR4 inhibition antagonizing eotaxin-1 induction. H2O2-upregulated phosphorylation of JNK and p38 MAPK was dampened by adding astragalin to epithelial cells, while this compound enhanced epithelial activation of Akt and ERK. H2O2 and LPS promoted epithelial apoptosis concomitant with nuclear condensation or caspase-3 activation, which was blunted by astragalin.ConclusionsAstragalin ameliorated oxidative stress-associated epithelial eosinophilia and apoptosis through disturbing TLR4-PKCβ2-NADPH oxidase-responsive signaling. Therefore, astragalin may be a potent agent antagonizing endotoxin-induced oxidative stress leading to airway dysfunction and inflammation.

BackgroundFibrotic remodeling of airway and lung parenchymal compartments is attributed to pulmonary dysfunction with an involvement of reactive oxygen species (ROS) in chronic lung diseases such as idiopathic pulmonary fibrosis and asthma.MethodsThe in vitro study elucidated inhibitory effects of astragalin, kaempferol-3-O-glucoside from leaves of persimmon and green tea seeds, on oxidative stress-induced airway fibrosis. The in vivo study explored the demoting effects of astragalin on epithelial to mesenchymal transition in BALB/c mice sensitized with ovalbumin (OVA).ResultsThe exposure of 20 μM H2O2 for 72 h accelerated E-cadherin loss and vimentin induction in airway epithelial BEAS-2B cells, which was reversed by non-toxic astragalin at 1–20 μM. Astragalin allayed the airway tissue levels of ROS and vimentin enhanced by OVA challenge. Collagen type 1 production increased in H2O2–exposed epithelial cells and collagen fiber deposition was observed in OVA-challenged mouse airways. This study further investigated that the oxidative stress-triggered autophagic regulation was responsible for inducing airway fibrosis. H2O2 highly enhanced the expression induction of the autophagy-related beclin-1 and light chains 3A/B (LC3A/B) within 4 h and astragalin blocked such induction by H2O2. This compound deterred the ROS-promoted autophagosome formation in BEAS-2B cells. Consistently, in OVA-sensitized mice the expression of beclin-1 and LC3A/B was highly induced, and oral administration of astragalin suppressed the autophagosome formation with inhibiting the induction of these proteins in OVA-challenged airway subepithelium. Induction of autophagy by spermidine influenced the epithelial induction of E-cadherin and vimentin that was blocked by treating astragalin.ConclusionThese results demonstrate that astragalin can be effective in allaying ROS-promoted bronchial fibrosis through inhibiting autophagosome formation in airways.

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Objective：A significant proportion of children with autism spectrum disorders (ASD) have regression characterized by loss of previously acquired skills. The purpose of this study was to compare demographic, clinical characteristics and autism-related symptomatology of the children who have regression with children who don't have regression.Methods：The subjects with ASD and their unaffected siblings (SIB) were recruited from the Korean Autism Genetic Study Consortium. Typically developing children (TC) were volunteered from community. The subjects were administered the Korean version of Autism Diagnostic Interview-Revised (K-ADI-R) and the Korean version of Autism Diagnostic Observation Schedule (K-ADOS) to diagnose or exclude ASD. Regression was defined on the basis of K-ADI-R data. The Korean version of Vineland Adaptive Behavior Scale (K-VABS), Aberrant Behavior Checklist (K-ABC) and Social Responsiveness Scale (K-SRS) were obtained from their parents.Results：Regression occurred in 8.33% (n=14) of children with ASD (n=168). Any SIB (n=166) and TC (n=53) did not experience regression. Regression was associated with lower IQ and lower score of K-VABS. There was no difference in autism symptom severity and K-ABC, K-SRS scores, between children with ASD who experienced regression and who did not.Conclusion：Regression seems to be a distinctive feature of ASD. Regression is associated with cognitive and more general functions, rather than symptoms specific to autism. KEY WORDS：Autism Spectrum DisordersㆍRegressionㆍAutism Diagnostic Interview-Revised.