Esophageal Helicobacter pylori colonization aggravates esophageal injury caused by reflux.
OBJECTIVE
To investigate esophageal Helicobacter pylori (H. pylori) colonization on esophageal injury caused by reflux and the related mechanisms.


METHODS
An esophagitis model, with acid and bile reflux, was surgically produced in male rats. The rats were randomly divided into either: (1) an esophagogastroduodenal anastomosis (EGDA) group; (2) an EGDA with H. pylori infection group; (3) a pseudo-operation with H. pylori infection group; or (4) a pseudo-operation group. All rats were kept for 36 wk. Based on the location of H. pylori colonization, the EGDA rats with H. pylori infection were subdivided into those with concomitant esophageal H. pylori colonization or those with only gastric H. pylori colonization. The esophageal injuries were evaluated grossly and microscopically. The expressions of CDX2 and MUC2 were determined by real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. Ki-67 antigen expression was determined by immunohistochemistry. The mRNA levels of cyclin D1, c-Myc, Bax and Bcl-2 were determined by RT-PCR. Cell apoptosis was evaluated using the TdT-mediated dUTP nick-end labeling method.


RESULTS
Esophagitis, Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC) developed in rats that underwent EGDA. When comparing rats with EGDA and concomitant esophageal H. pylori colonization to EGDA-only rats, the severity of injury (87.9 ± 5.2 vs 77.2 ± 8.6, macroscopically, 92.5 ± 8.0 vs 83.8 ± 5.5, microscopically, both P < 0.05) and the incidences of BE (80.0% vs 33.3%, P = 0.055) and EAC (60.0% vs 11.1%, P < 0.05) were increased. These increases were associated with upregulation of CDX2 and MUC2 mRNA (10.1 ± 5.4 vs 3.0 ± 2.9, 8.4 ± 4.6 vs 2.0 ± 3.2, respectively, Ps < 0.01) and protein (8.1 ± 2.3 vs 3.3 ± 3.1, 7.3 ± 4.0 vs 1.8 ± 2.7, respectively, all P < 0.05). The expression of Ki-67 (8.9 ± 0.7 vs 6.0 ± 1.7, P < 0.01) and the presence of apoptotic cells (8.3 ± 1.1 vs 5.3 ± 1.7, P < 0.01) were also increased significantly in rats with EGDA and concomitant esophageal H. pylori colonization compared with rats with EGDA only. The mRNA levels of cyclin D1 (5.8 ± 1.9 vs 3.4 ± 1.3, P < 0.01), c-Myc (6.4 ± 1.7 vs 3.7 ± 1.2, P < 0.01), and Bax (8.6 ± 1.6 vs 5.1 ± 1.3, P < 0.01) were significantly increased, whereas the mRNA level of Bcl-2 (0.6 ± 0.3 vs 0.8 ± 0.3, P < 0.01) was significantly reduced in rats with EGDA and concomitant esophageal H. pylori colonization compared with rats with EGDA only.


CONCLUSIONS
Esophageal H. pylori colonization increases esophagitis severity, and facilitates the development of BE and EAC with the augmentation of cell proliferation and apoptosis in esophageal mucosa.
Yun-Xiang Chu, Wei-Hong Wang, Yun Dai, Gui-Gen Teng, Shu-Jun Wang, Department of Gastroenterology, Peking University First Hospital, Beijing 100034, China.
Yun-Xiang
YX
Chu
Yun-Xiang Chu, Wei-Hong Wang, Yun Dai, Gui-Gen Teng, Shu-Jun Wang, Department of Gastroenterology, Peking University First Hospital, Beijing 100034, China.
Wei-Hong
WH
Wang
Yun-Xiang Chu, Wei-Hong Wang, Yun Dai, Gui-Gen Teng, Shu-Jun Wang, Department of Gastroenterology, Peking University First Hospital, Beijing 100034, China.
Yun
Y
Dai
Yun-Xiang Chu, Wei-Hong Wang, Yun Dai, Gui-Gen Teng, Shu-Jun Wang, Department of Gastroenterology, Peking University First Hospital, Beijing 100034, China.
Gui-Gen
GG
Teng
Yun-Xiang Chu, Wei-Hong Wang, Yun Dai, Gui-Gen Teng, Shu-Jun Wang, Department of Gastroenterology, Peking University First Hospital, Beijing 100034, China.
Shu-Jun
SJ
Wang
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D000818:Animals; D017209:Apoptosis; D001471:Barrett Esophagus / Q000235:genetics / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D000071616:CDX2 Transcription Factor; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D004938:Esophageal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D004942:Esophagitis, Peptic / Q000235:genetics / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D004947:Esophagus / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D005764:Gastroesophageal Reflux / Q000150:complications*; D005786:Gene Expression Regulation; D016481:Helicobacter Infections / Q000150:complications / Q000235:genetics / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000472:pathogenicity*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D055262:Mucin-2 / Q000235:genetics / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D012720:Severity of Illness Index; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
C494828:Bax protein, rat; D000071616:CDX2 Transcription Factor; C530106:Ccnd1 protein, rat; C541055:Cdx2 protein, rat; D018398:Homeodomain Proteins; D019394:Ki-67 Antigen; C524628:Muc2 protein, rat; D055262:Mucin-2; D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D014157:Transcription Factors; D051028:bcl-2-Associated X Protein; D019938:Cyclin D1
Adenocarcinoma; Animal model; Esophagus; Helicobacter pylori; Metaplasia