2. Academic Validation
  3. H. pylori infection confers resistance to apoptosis via Brd4-dependent BIRC3 eRNA synthesis

H. pylori infection confers resistance to apoptosis via Brd4-dependent BIRC3 eRNA synthesis

  • Cell Death Dis. 2020 Aug 21;11(8):667. doi: 10.1038/s41419-020-02894-z.
Yanheng Chen  # 1,  Donald Sheppard  # 1,  Xingchen Dong 1,  Xiangming Hu 2,  Meihua Chen 3,  Ruichuan Chen 3,  Jayati Chakrabarti 4 5,  Yana Zavros 4 5,  Richard M Peek 6,  Lin-Feng Chen 7 8
Affiliations

Affiliations

  • 1 Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA.
  • 2 Fujian Key Laboratory for Translational Research in Cancer and Neurodegenerative Diseases, Institute for Translational Medicine, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, 350122, China.
  • 3 The State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, 361101, China.
  • 4 Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, 45267, OH, USA.
  • 5 Department of Cellular and Molevular Medicine, College of Medicine, University of Arizona-Tucson, Tucson, 85724, AZ, USA.
  • 6 Division of Gastroenterology, Department of Medicine and Cancer Biology, Vanderbilt University School of Medicine, Nashville, 37232, TN, USA.
  • 7 Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA. lfchen@illinois.edu.
  • 8 Carle R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA. lfchen@illinois.edu.
  • # Contributed equally.
PMID: 32820150 DOI: 10.1038/s41419-020-02894-z
Abstract

H. pylori Infection is one of the leading causes of gastric Cancer and the pathogenicity of H. pylori Infection is associated with its ability to induce chronic inflammation and Apoptosis resistance. While H. pylori infection-induced expression of pro-inflammatory cytokines for chronic inflammation is well studied, the molecular mechanism underlying the Apoptosis resistance in infected cells is not well understood. In this study, we demonstrated that H. pylori infection-induced Apoptosis resistance in gastric epithelial cells triggered by Raptinal, a drug that directly activates Caspase-3. This resistance resulted from the induction of cIAP2 (encoded by BIRC3) since depletion of BIRC3 by siRNA or inhibition of cIAP2 via BV6 reversed H. pylori-suppressed Caspase-3 activation. The induction of cIAP2 was regulated by H. pylori-induced BIRC3 eRNA synthesis. Depletion of BIRC3 eRNA decreased H. pylori-induced cIAP2 and reversed H. pylori-suppressed Caspase-3 activation. Mechanistically, H. pylori stimulated the recruitment of bromodomain-containing factor Brd4 to the enhancer of BIRC3 and promoted BIRC3 eRNA and mRNA synthesis. Inhibition of Brd4 diminished the expression of BIRC3 eRNA and the anti-apoptotic response to H. pylori Infection. Importantly, H. pylori isogenic cagA-deficient mutant failed to activate the synthesis of BIRC3 eRNA and the associated Apoptosis resistance. Finally, in primary human gastric epithelial cells, H. pylori also induced resistance to Raptinal-triggered Caspase-3 activation by activating the Brd4-dependent BIRC3 eRNA synthesis in a CagA-dependent manner. These results identify a novel function of Brd4 in H. pylori-mediated Apoptosis resistance via activating BIRC3 eRNA synthesis, suggesting that Brd4 could be a potential therapeutic target for H. pylori-induced gastric Cancer.

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