Cellular stress and redox activity proteins are involved in gastric carcinogenesis associated with Helicobacter pylori infection expressing high levels of thioredoxin-1 / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Helicobacter pylori infection is related to the development of gastric diseases. Our previous studies showed that high thioredoxin-1 (Trx1) expression in H. pylori can promote gastric carcinogenesis. To explore the underlying molecular mechanisms, we performed an isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic analysis of stomach tissues from Mongolian gerbil infected with H. pylori expressing high and low Trx1. Differences in the profiles of the expressed proteins were analyzed by bioinformatics and verified using Western blot analysis. We found three candidate proteins, 14-3-3α/β, glutathione-S-transferase (GST), and heat shock protein 70 (HSP70), in high Trx1 tissues compared with low Trx1 tissues and concluded that cellular stress and redox activity-related proteins were involved in the pathogenesis of gastric cancer associated with H. pylori Trx1.

14-3-3epsilon protein increases matrix metalloproteinase-2 gene expression via p38 MAPK signaling in NIH3T3 fibroblast cells

One of the 14-3-3 protein isoforms, 14-3-3epsilon, was previously shown to be increased during skin aging. We suggest here a possible role for the 14-3-3epsilon protein in skin aging by providing evidence that 14-3-3epsilon increases the expression of the matrix-metalloproteinase (MMP)-2 gene in NIH3T3 fibroblast cells. Expression of the 14-3-3epsilon gene in NIH3T3 cells primarily up-regulated the expression of the MMP-2 gene at the transcriptional level by inducing specific DNA binding proteins bound to an upstream region of the MMP-2 promoter from -1,629 to -1,612. Inhibition of endogenous 14-3-3epsilon gene expression by RNA interference also decreased endogenous MMP-2 gene expression. Furthermore, up-regulation of the MMP-2 gene by 14-3-3epsilon was suppressed by expression of a dominant-negative mutant of p38 MAP kinase. These findings strongly suggest that increased expression of 14-3-3epsilon contributes to remodeling of extracellular matrix in skin through increasing MMP-2 gene expression via p38 MAP kinase signaling.