Transforming growth factor beta: a role in the upper airway and rhinosinusitis-Dermatophagoides pteronyssinus-induced apoptosis with pulmonary alveolar cells.

BACKGROUND: There is a link with the upper and lower airway and disruption of alveolar epithelial cells, which is a potential trigger for the reactivation of the epithelial-mesenchymal trophic unit (EMTU) and induced characteristic airway changes associated with allergic asthma. Dermatophagoides pteronyssinus is a common inhalant indoor allergen and is known for causing allergic rhinitis and airway inflammation. Transforming growth factor beta 1 (TGF-beta1) is a major participant in the airway remodeling of asthma, a component of cellular stress response pathways, and enhanced epithelial immunoreactivity is known to occur in allergic rhinitis. METHODS: In this study, we show the ability of D. pteronyssinus allergens from dialyzed standardized immunotherapy extract to induce apoptosis and increase TGF-beta1 secretion in a confluent A549 cell line model. A549 cells were treated with either 600 AU/mL dialyzed D. pteronyssinus immunotherapy extract (eDp) or Ctl media (Ctl) for 24 hours. Cells and supernatants were collected, washed, and treated with Annexin V-FITC Apoptosis Detection Kit II (BD Pharmingen, La Jolla, CA) and then analyzed by flow cytometry. TGF-beta1 secretion was determined by ELISA using cell culture supernatants. RESULTS: The eDp group showed a fourfold increase in early apoptotic cells with a twofold increase in late apoptotic cells versus the Ctl group, along with a 1.65-fold increase of TGF-beta1. CONCLUSION: eDp induced viable A549 cells to undergo apoptosis determined by flow cytometry analysis with a significant increase in TGF-beta1 secretion compared with Ctl.

A ChIP-cloning approach linking SIRT1 to transcriptional modificationof DNA targets.

The mammalian protein deacetylase SIRT1 (sirtuin1) is widely recognized for its link to calorie restriction and longevity. SIRT1 not only modulates the function of protein targets such as p53 or NFkappaB, but it also affects gene transcription by causing hypoacetylation of associated nucleosomal histones. However, the identification of SIRT1-specific DNA targets that confer chromosomal stability and cell longevity have remained elusive. Here, we report the usefulness of a ChIP-cloning approach for the identification of an endogenous DNA target intimately linked with SIRT1 activity. Using the aforementioned technique, we identified a gene encoding the neuro-oncological ventral antigen2 (nova2) as a SIRT1 target. Nova2 regulates the alternative splicing of scn1a, which encodes the alpha-subunit of a neuronal sodium channel targeted by antiepileptic drugs. This finding demonstrates that ChIP-cloning is an innovative approach for the identification of SIRT1-specific DNA targets.