Published online Mar 7, 2018. doi: 10.3748/wjg.v24.i9.982
Peer-review started: December 9, 2017
First decision: December 20, 2017
Revised: December 26, 2017
Accepted: January 23, 2018
Article in press: January 23, 2018
Published online: March 7, 2018
Processing time: 86 Days and 8.4 Hours
Barrett’s esophagus is a major complication of gastro-esophageal reflux disease (GERD) and an important precursor lesion for the development of esophageal adenocarcinoma. However, the cellular and molecular mechanisms of Barrett’s metaplasia remain unclear. It has been demonstrated that poly(ADP-ribose) polymerases (PARPs)-associated ADP-ribosylation plays an important role in DNA damage and inflammatory response. Although PARP1-associated ADP-ribosylation has been examined both in vivo and in vitro, the function of PARP1 in esophageal epithelial cells and Barrett’s esophagus has not been illustrated.
In this study, the potential role of PARP1 and PARP1-related oxidative damage in Barrett’s esophagus was investigated.
The study investigated the potential role of PARP1 in oxidative damage in Barrett’s esophagus, which is urgent and essential for developing therapeutic targets.
Expression of PARP1 gene was analyzed using microarray analysis in patient esophageal tissue samples. A Barrett’s esophagus mouse model was established to examine the esophageal morphological changes and molecular changes. qPCR was used to examine the PARP1 expression in cell lines after treatment with H2O2 and bile acids (pH 4). To evaluate the impact of PARP1 activity on cell survival and DNA damage response after oxidative stress, immunofluorescence staining, comet assay, and annexin V staining were used.
High expression of PARP1 was associated with Barrett’s esophagus. Positive staining for NF-κB, γH2AX, and poly(ADP-ribose) was observed in the mouse model of Barrett’s esophagus. Knockdown of PARP1 decreased the cell viability following treatment with H2O2 and bile acids (pH 4). We further demonstrated that PARP1 inhibition could increase the oxidative damage as demonstrated by an increase in the levels of H2O2, intracellular reactive oxygen species, oxidative DNA damage, double-strand breaks, and apoptosis.
The dysfunction of PARP1 in esophageal epithelial cells increases the levels of reactive oxygen species and oxidative DNA damage, and downregulation of PARP1 or PARP1 inhibitor may be a potential therapeutic strategy for Barrett’s esophagus.
This study will provide an example for investigating the relationship between the oxidative DNA damage and Barrett’s metaplasia, and the underlying role of the PARP1 in Barrett’s esophagus. The direction of the future research is to provide more evidence for developing novel strategies by targeting PARP1 in Barrett’s esophagus. In our future research, the PARP1-related downstream signaling pathway (inflammation or DNA damage) will be tested in Barrett’s esophagus epithelial cells or animal models to observe the inhibitory effect of PARP1.