Airway epithelial cells harbor the capacity of active Cl transepithelial transport and play critical roles in modulating innate immunity. However, whether intracellular Cl accumulation contributes to relentless airway inflammation remains largely unclear. This study showed that, in airway epithelial cells, intracellular Cl concentration ([Cl]) was increased after Pseudomonas aeruginosa lipopolysaccharide (LPS) stimulation via nuclear factor-κB (NF-κB)-phosphodiesterase 4D (PDE4D)-cAMP signaling pathways. Clamping [Cl] at high levels or prolonged treatment with LPS augmented serum- and glucocorticoid-inducible protein kinase 1 (SGK1) phosphorylation and subsequently triggered NF-κB activation in airway epithelial cells, whereas inhibition of SGK1 abrogated airway inflammation in vitro and in vivo. Furthermore, Cl-SGK1 signaling pathway was pronouncedly activated in patients with bronchiectasis, a chronic airway inflammatory disease. Conversely, hydrogen sulfide (HS), a sulfhydryl-containing gasotransmitter, confers anti-inflammatory effects through decreasing [Cl] via activation of cystic fibrosis transmembrane conductance regulator (CFTR). Our study confirms that intracellular Cl is a crucial mediator of sustained airway inflammation. Medications that abrogate excessively increased intracellular Cl may offer novel targets for the management of airway inflammatory diseases.

No abstract

No abstract

No abstract

Cepharanthine, a biscoclaurine alkaloid isolated from the roots of Stephania cephalantha Hayata, has been reported to demonstrate antitumor activity across multiple cancer types; however, the mechanisms are still under investigation. High transcriptional responses by both the Hedgehog and Wnt pathways are frequently associated with specific human cancers, including liver cancer. To investigate whether these signaling pathways are involved in the pharmaceutical action of cepharanthine, we investigated Hedgehog and Wnt signaling in models of liver cancer treated with a semi-synthetic cepharanthine derivative, cepharanthine hydrochloride (CH), in vitro and in vivo. By using MTT cytotoxic, scratch, Transwell, colony formation and flow cytometry assays, the pharmaceutical effect of CH was assessed. The compound was found to inhibit cellular proliferation and invasion, and promote apoptosis. Subsequent mechanistic investigations revealed that CH suppressed the Hedgehog/Gli1 signaling pathway by inhibiting Gli1 transcription and its transcriptional activity. CH also inhibited Wnt/β-catenin signaling, and the pathway was found to be an upstream regulator of Hedgehog signaling in CH-treated liver cancer cells. Finally, the antitumor effects of CH were demonstrated in an in vivo xenograft tumor model. Immunohistochemical analysis indicated that Gli1 protein levels were diminished in CH-treated xenografts, compared with that noted in the controls. In summary, our results highlight a novel pharmaceutical antitumor mechanism of cepharanthine and provide support for CH as a clinical therapy for refractory liver cancer and other Wnt/Hedgehog-driven cancers.