Mucus hypersecretion is commonly observed in many chronic airway inflammatory diseases. Mucin 5AC (MUC5AC) is a major airway mucin because of its high expression in goblet cells. Here, the authors identified a gene called SAM domain–containing prostate-derived Ets factor (SPDEF) that was induced by interleukin (IL)-13. Their results showed that specific knockdown of SPDEF reduced IL-13-induced MUC5AC expression in human airway epithelial cells. This finding was associated with decreased expression of anterior gradient 2 (AGR2) and Ca2+-activated Cl− channel (CLCA1), which regulate IL-13-mediated MUC5AC overproduction. Furthermore, transfection with SPDEF siRNA enhanced expression of forkhead box a2 (Foxa2), a key transcription factor that is known to prevent mucus production. The authors also demonstrated that the repression of STAT6 inhibited expression of SPDEF and MUC5AC induced by IL-13. These results show that SPDEF plays a critical role in regulating a transcriptional network mediating IL-13-induced MUC5AC synthesis dependent on STAT6.
1 January 2011 in Cellular Physiology and Biochemistry
To explore the signaling mechanism associated with the inhibitory effect of nicotine on tumor necrosis factor (TNF)- α expression in human airway epithelial cells. HBE16 airway epithelial cells were cultured and incubated with either nicotine or cigarette smoke extract (CE). Cells were then transfected with α1, α5, or α7 nicotinic acetylcholine receptor (nAChR)-specific small interfering RNAs (siRNAs). The effects of nicotine on the production of proinflammatory factors TNF-α, in transfected cells were analyzed. Furthermore, we assayed the expression levels of myeloid differentiation primary response gene 88 (MyD88) protein, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 protein, NF-κB activity and NF-κB inhibitor alpha (I-κBα) expression in cells after treatment with nicotine or α7 nAChR inhibitor, α -bungarotoxin (α-BTX). The production of TNF-α was lower in cells pretreated with nicotine before lipopolysaccharide (LPS) stimulation, compared with LPS-only-treated cells. In contrast, in α7 siRNA-transfected cells incubated with nicotine and LPS, TNF-α expression was higher than that in non-transfected cells or in α1 or α5 siRNA-transfected cells. Addition of MyD88 siRNA or the NF-κB inhibitor pyridine-2,6-dithiocarboxylic acid (PDTC) also reduced TNF-α expression. Furthermore, we found that nicotine decreased MyD88 protein, NF-κB p65 protein, NF-κB activity and phospho-I-κBα expression induced by CE or LPS. The inhibitor α-BTX could reverse these effects. Nicotine reduces TNF-α expression in HBE16 airway epithelial cells, mainly through an α7 nAChR/MyD88/NF-κB pathway.
Spirometry is the most common method to assess respiratory function. It is widely used to obtain objective information for the diagnosis of respiratory diseases and monitoring the functional state of the respiratory system. In 2014, the Russian Respiratory Society approved the technical standards for performing spirometry. Improvements in measuring devices have necessitated updating technical standards and standardizing the result interpretation algorithm.Methods. This document on spirometry was prepared by a joint group of experts from the Russian Respiratory Society and the Russian Association of Specialists in Functional Diagnostics, who have experience in performing spirometry in accordance with quality criteria, analyzing the results of the study, and developing national standards.Results. The 2014 Spirometry Technical Standards were revised, including the addition of quality criteria for measurements and test quality assessment. Where necessary, evidence was provided to support the change. The experience and knowledge of the expert group members were used to develop these recommendations.Conclusion. Standards for spirometry and bronchodilator test and the result interpretation algorithm are presented to improve the measurement quality and consistency of data interpretation.
The complexity of the pathogenetic mechanisms of the development of chronic inflammation in asthma determines its heterogeneity and insufficient treatment effectiveness. Nuclear transcription factors, which include peroxisome proliferator-activated receptors, that is, PPARs, play an important role in the regulation of initiation and resolution of the inflammatory process. The ability of PPARs to modulate not only lipid homeostasis but also the activity of the inflammatory response makes them an important pathogenetic target in asthma therapy. At present, special attention is focused on natural (polyunsaturated fatty acids (PUFAs), endocannabinoids, and eicosanoids) and synthetic (fibrates, thiazolidinediones) PPAR ligands and the study of signaling mechanisms involved in the implementation of their anti-inflammatory effects in asthma. This review summarizes current views on the structure and function of PPARs, as well as their participation in the pathogenesis of chronic inflammation in asthma. The potential use of PPAR ligands as therapeutic agents for treating asthma is under discussion.