12-448 Sigma-AldrichGoat Anti-Rabbit IgG Antibody, Alkaline Phosphatase conjugate

The aim of the present study was to map the distribution of representative protein components of the renin-angiotensin system (RAS) in the human gastric mucosa.Biopsies from the antral and corporal mucosa of healthy Helicobacter pylori negative and positive volunteers were assessed by histology, Western blot and immunohistochemistry for angiotensin II subtype 1 and 2 receptors (AT1R, AT2R) and other RAS components (angiotensinogen, renin, angiotensin converting enzyme, and neprilysin). Mucosal levels of myeloperoxidase (MPO) served as a protein marker of neutrophil infiltration.AT1R and AT2R were located in a variety of cells in the human gastric mucosa, including AT1R on a subpopulation of endocrine cells in the antral mucosa. Angiotensinogen and renin were expressed by resident mesenchymal cells in lamina propria. All investigated RAS components were found in vascular endothelial cells. The AT1R protein expression was 3-4 times higher in the gastric mucosa of H. pylori positive subjects compared to the gastric mucosa of H. pylori negative subjects (p less than 0.05). Gastric mucosal AT1R protein expression correlated positively with neutrophil infiltration (r = 0.7, p less than 0.05).Protein components of RAS are present in the human gastric mucosa. The results suggest an angiotensin II mediated impact on mucosal epithelial functions, antral endocrine properties, microvascular permeability, and gastric inflammation.

Genomes can encode a variety of proteins with unrelated architectures and activities. It is known that protein-coding genes of de novo origin have significantly contributed to this diversity. However, the molecular mechanisms and evolutionary processes behind these originations are still poorly understood. Here we show that the last 102 codons of a novel gene, Noble, assembled directly from non-coding DNA following an intronic deletion that induced alternative intron retention at the Drosophila melanogaster Rieske Iron Sulphur Protein (RFeSP) locus. A systematic analysis of the evolutionary processes behind the origin of Noble showed that its emergence was strongly biased by natural selection on and around the RFeSP locus. Noble mRNA is shown to encode a bona fide protein that lacks an iron sulphur domain and localizes to mitochondria. Together, these results demonstrate the generation of a novel protein at a naturally selected site.

The role of the renin-angiotensin system in gastric physiology and disease has as yet been sparsely explored. The first aim of the study was to investigate the baseline presence and location of angiotensin II receptors (AT1R and AT2R) in the stomach of the Mongolian gerbil. A second aim was to elucidate whether the presence of H. pylori infection is associated with changes in the expression of these receptors.H. pylori-negative and H. pylori-infected (strain SS1 or TN2GF4) male Mongolian gerbils were investigated. The stomachs were examined at six or 12 months after inoculation by the use of immunohistochemistry, western blot and microscopic morphometry.AT1R and AT2R were located in a variety of cells in the gerbil gastric wall, including a subpopulation of endocrine cells in the antral mucosa and inflammatory cells infiltrating H. pylori-infected stomachs. Gerbils infected with the SS1 strain showed a significantly increased antral AT1R protein expression and an increased number of infiltrating polymorphonuclear leucocytes (PMNs) at 12 months. The AT1R protein expression correlated with the number of PMNs and the antral expression of myeloperoxidase.Angiotensin II receptors are present in a variety of cells in the gastric wall of the Mongolian gerbil. The results indicate an influence dependent on the H. pylori strain on the gastric AT1R expression and a relationship between gastric AT1R expression and mucosal PMNs infiltration.