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Regulation of Noxa‐mediated apoptosis in Helicobacter pylori‐infected gastric epithelial cells
Author(s) -
Rath Suvasmita,
Das Lopamudra,
Kokate Shrikant Babanrao,
Pratheek B. M.,
Chattopadhyay Subhasis,
Goswami Chandan,
Chattopadhyay Ranajoy,
Crowe Sheila Eileen,
Bhattacharyya Asima
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.14-257501
Subject(s) - mcl1 , apoptosis , immunoprecipitation , flow cytometry , phosphorylation , helicobacter pylori , cancer research , chromatin immunoprecipitation , biology , in vitro , chemistry , microbiology and biotechnology , downregulation and upregulation , immunology , antibody , biochemistry , gene expression , genetics , promoter , gene
Helicobacter pylori induces the antiapoptotic protein myeloid cell leukemia 1 (Mcl1) in human gastric epithelial cells (GECs). Apoptosis of oncogenic protein Mcl1‐expressing cells is mainly regulated by Noxa‐mediated degradation of Mcl1. We wanted to elucidate the status of Noxa in H. pylori ‐infected GECs. For this, various GECs such as AGS, MKN45, and KATO III were either infected with H. pylori or left uninfected. The effect of infection was examined by immunoblotting, immunoprecipitation, chromatin immunoprecipitation assay, in vitro binding assay, flow cytometry, and confocal microscopy. Infected GECs, surgical samples collected from patients with gastric adenocarcinoma as well as biopsy samples from patients infected with H. pylori showed significant up‐regulation of both Mcl1 and Noxa compared with noninfected samples. Coexistence of Mcl1 and Noxa was indicative of an impaired Mcl‐Noxa interaction. We proved that Noxa was phosphorylated at Ser 13 residue by JNK in infected GECs, which caused cytoplasmic retention of Noxa. JNK inhibition enhanced Mcl1‐Noxa interaction in the mitochondrial fraction of infected cells, whereas overexpression of nonphosphorylatable Noxa resulted in enhanced mitochondria‐mediated apoptosis in the infected epithelium. Because phosphorylation‐dephosphorylation can regulate the apoptotic function of Noxa, this could be a potential target molecule for future treatment approaches for H. pylori ‐induced gastric cancer.—Rath, S., Das, L., Kokate, S. B., Pratheek, B. M., Chattopadhyay, S., Goswami, C., Chattopadhyay, R., Crowe, S. E., Bhattacharyya, A., Regulation of Noxa‐mediated apoptosis in Helicobacter pylori –infected gastric epithelial cells. FASEB J. 29, 796–806 (2015). www.fasebj.org