Cortactin Mediates Apoptosis of Gastric Epithelial Cells Induced by VacA Protein of Helicobacter pylori

• Published in: Digestive diseases and sciences 2016-01, Vol.61 (1), p.80-90
• Main Authors: Chang, Hui, Chen, Dongfeng, Ni, Bosheng, Zuo, Qianfei, Wang, Chunhua, Han, Ran, Lan, Chunhui
• Format: Article
• Language: English
• Subjects: Antigens; Apoptosis; Bacterial Proteins - metabolism; bcl-2-Associated X Protein - metabolism; Biochemistry; Cell Line, Tumor; Cortactin - genetics; Cortactin - metabolism; Epithelial Cells - metabolism; Epithelial Cells - microbiology; Epithelial Cells - pathology; Gastric Mucosa - metabolism; Gastric Mucosa - microbiology; Gastric Mucosa - pathology; Gastroenterology; Helicobacter pylori; Hepatology; Humans; Medicine; Medicine & Public Health; Oncology; Original Article; Proteins; Proto-Oncogene Proteins c-bcl-2 - metabolism; RNA Interference; Signal Transduction; Stomach cancer; Transduction, Genetic; Transfection; Transplant Surgery
• ISSN: 0163-2116; 1573-2568
• DOI: 10.1007/s10620-015-3836-0

Background Vacuolating cytotoxin antigen (VacA) is one of the major virulence factors in Helicobacter pylori ( H. pylori ), which is responsible for cell vacuolar degeneration and apoptotic cell death. A candidate host factor which mediates this process is cortactin, a protein associated with the processes of colonization and adhesion of H. pylori in gastric epithelium. Aim To investigate the role of cortactin in VacA-induced apoptosis of gastric epithelial cells. Methods Cortactin expression and shRNA lentiviral constructs were developed and transduced into the human gastric cancer cell line, AGS. VacA protein was purified from H. pylori cultures, acid-activated, and co-incubated with the transduced cell populations. Apoptosis was detected by flow cytometry, and the levels of the pro- and anti-apoptotic proteins Bax and Bcl-2 were determined by Western blot. Results Acid-activated purified VacA induced apoptosis in the parental AGS cells. Increased expression of cortactin (AGS/cortactin) led to a greater percentage of cells undergoing apoptosis. In contrast, knockdown of cortactin with shRNA (AGS/cortactin-shRNA) decreased the percentage of apoptotic cells. The protein levels of pro- and anti-apoptotic proteins Bax and Bcl-2 were increased and decreased in AGS/cortactin cells relative to the parental AGS cells. In the AGS/cortactin-shRNA cells, Bax protein levels were decreased, while Bcl-2 protein was increased. Conclusions The results indicate that cortactin is involved in the regulation of apoptosis induced by VacA in gastric cells.