Deoxycholate induces apoptosis in cultured normal human esophageal mucosal epithelial cells

Abstract

Abstract: Objective To study the effect of deoxycholate in inducing apoptosis of human normal esophageal mucosal epithelial cells in vitro and investigate the molecular mechanism. Methods Cultured normal human esophageal mucosal epithelial cells were treated with deoxycholate, and the cell apoptosis were evaluated with TUNEL, DNA ladder, flow cytometry with PI-staining, Annexin V-FITC conjugated with PI staining, and Western blotting. Results Flow cytometry, TUNEL and DNA ladder demonstrated that deoxycholate could induce apoptosis in normal human esophageal mucosal epithelial cells in a dose- and time-dependent manner. A percentage of 21.3% of the cell population treated with deoxycholate at 500 μmol/L for 30 min exhibited detectable caspase-3 activity shown by flow cytometry, which was significantly higher than the control level (1.5%, P<0.01). Western blotting suggested that deoxycholate down-regulated Bcl-2 protein expression and up-regulated Bax expression, but Fas was negative in the cells before and after deoxycholate treatment. Conclusions Deoxycholate could induce apoptosis in cultured human esophageal mucosal epithelial cells. Aaspase-3 activation, Bcl-2 protein down-regulation and Bax up-regulation are involved in deoxycholate-induced apoptosis, which does not involve Fas-L/Fas.

CLC Number:

ZHANG Ru¹, GONG Jun¹, WANG Hui², WANG Li¹, RAN Li-wei¹. Deoxycholate induces apoptosis in cultured normal human esophageal mucosal epithelial cells[J]. Journal of Southern Medical University, 2005, 25(10): 1240-1243.

References

[1] Jankowski JA, Anderson M. Review article: management of oesophageal adenocarcinoma-control of acid, bile and inflammation in intervention strategies for Barrett’s oesophagus [J]. Aliment Pharmacol Ther, 2004, 20 (Suppl 5): 71-80.
[2] Stein HJ, Kauer WK, Feussner H, et al. Bile acids as components of the duodenogastric refluxate: detection, relationship to bilirubin,mechanism of injury, and clinical relevance [J]. Hepatogastroenterology, 1999, 46(25): 66-73.
[3] Torchia EC, Stolz A, Agellon LB. Differential modulation of cellular death and survival pathways by conjugated bile acids [J]. BMC Biochem, 2001, 2(1): 11.
[4] Schlottman K, Wachs FP, Krieg RC, et al. Characterization of bile salt-induced apoptosis in colon cancer cell lines [J]. Cancer Res,2000, 60(15): 4270-6.
[5] Shirvani VN, Ouatu-Lascar R, Kaur BS, et al. Cyclooxygenase 2 expression in Barrett’s esophagus and adenocarcinoma: Ex vivo induction by bile salts and acid exposure [J]. Gastroenterology,2000, 118(3): 487-96.
[6] Sawaoka H, Kawano S, Tsuji S, et al. Cyclooxygenase-2 inhibitors suppress the growth of gastric cancer xenografts via induction of apoptosis in nude mice [J]. Am J Physiol, 1998, 274 (6 Pt 1):G1061-7.
[7] 张茹,龚均,王晖,等.人正常食管黏膜上皮细胞的纯化分离和传代培养[J].第四军医大学学报,2005,26(16):1468-71.Zhang R, Gong J, Wang H, et al. Improvement of human esophageal squamous epithelial cells isolation and subculture [J]. J Fourth Mil Med Univ, 2005, 26(16): 1468-71.
[8] Kishida T, Taguchi F, Feng L, et al. Analysis of bile acids in colon residual liquid or fecal material in patients with colorectal neoplasia and control subjects[J]. J Gastroenterol, 1997, 32(3): 306-11.
[9] Sodeman T, Bronk SF, Roberts PJ, et al. Bile salts mediate hepatocyte apoptosis by increasing cell surface trafficking of Fas[J]. Am J Physiol Gastrointest Liver Physiol, 2000, 278(6): G992-9.
[10] Tsujimoto Y, Shimizu S. Bcl-2 family: life-or-death switch [J].FEBS Lett, 2000, 466(1): 6-10.