Temporal and Spatial Expression of Transforming Growth Factor-ß after Airway Remodeling to Tobacco Smoke in Rats.

Airway remodeling is strongly correlated with the progression of chronic obstructive pulmonary disease (COPD). In this study, our goal was to characterize progressive structural changes in site-specific airways, along with the temporal and spatial expression of transforming growth factor (TGF)-ß in the lungs of male spontaneously hypertensive rats exposed to tobacco smoke (TS). Our studies demonstrated that TS-induced changes of the airways is dependent on airway generation and exposure duration for proximal, midlevel, and distal airways. Stratified squamous epithelial cell metaplasia was evident in the most proximal airways after 4 and 12 weeks but with minimal levels of TGF-ß-positive epithelial cells after only 4 weeks of exposure. In contrast, epithelial cells in midlevel and distal airways were strongly TGF-ß positive at both 4 and 12 weeks of TS exposure. Airway smooth muscle volume increased significantly at 4 and 12 weeks in midlevel airways. Immunohistochemistry of TGF-ß was also found to be significantly increased at 4 and 12 weeks in lymphoid tissues and alveolar macrophages. ELISA of whole-lung homogenate demonstrated that TGF-ß2 was increased after 4 and 12 weeks of TS exposure, whereas TGF-ß1 was decreased at 12 weeks of TS exposure. Airway levels of messenger RNA for TGF-ß2, as well as platelet-derived growth factor-A, granulocyte-macrophage colony-stimulating factor, and vascular endothelial growth factor-α, growth factors regulated by TGF-ß, were significantly decreased in animals after 12 weeks of TS exposure. Our data indicate that TS increases TGF-ß in epithelial and inflammatory cells in connection with airway remodeling, although the specific role of each TGF-ß isoform remains to be defined in TS-induced airway injury and disease.

XA21-specific induction of stress-related genes following Xanthomonas infection of detached rice leaves.

The rice XA21 receptor kinase confers robust resistance to the bacterial pathogen Xanthomonas oryzaepv. oryzae (Xoo). We developed a detached leaf infection assay to quickly and reliably measure activation of the XA21-mediated immune response using genetic markers. We used RNA sequencing of elf18 treated EFR:XA21:GFP plants to identify candidate genes that could serve as markers for XA21 activation. From this analysis, we identified eight genes that are up-regulated in both in elf18 treated EFR:XA21:GFP rice leaves and Xoo infected XA21 rice leaves. These results provide a rapid and reliable method to assess bacterial-rice interactions.

Draft Genome Sequence of Piscirickettsia litoralis, Isolated from Seawater.

One species of Piscirickettsia, a pathogen of salmonid fish, has been described. The genome sequence of a putative second and free-living species may provide insights into the evolution of pathogenicity in the genus.