Basic Research
Copyright ©2007 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 21, 2007; 13(47): 6370-6378
Published online Dec 21, 2007. doi: 10.3748/wjg.v13.i47.6370
Probiotic bacteria change Escherichia coli-induced gene expression in cultured colonocytes: Implications in intestinal pathophysiology
Pinaki Panigrahi, Gheorghe T Braileanu, Hegang Chen, O Colin Stine
Pinaki Panigrahi, Gheorghe T Braileanu, Departments of Pediatrics, University of Maryland School of Medicine, 22 South Greene Street, Baltimore, MD 21201, United States
Hegang Chen, Department of Epidemiology & Preventive Medicine, University of Maryland School of Medicine, 22 South Greene Street, Baltimore, MD 21201, United States
O Colin Stine, Genomics Core, University of Maryland School of Medicine, 22 South Greene Street, Baltimore, MD 21201, United States
Author contributions: All authors contributed equally to the work.
Supported by the Department of Pediatrics and GCRC (M01-RR-16500), University of Maryland Baltimore, with partial funding from NIH grants UO1 HD 40574 and RO1 HD 053719
Correspondence to: Dr. Pinaki Panigrahi, University of Maryland School of Medicine, Department of Pediatrics, 22 South Greene Street, N5W68, Baltimore, MD 21201, United States. ppanigrahi@pol.net
Telephone: +1-410-7061803 Fax: +1-410-7060404
Received: July 25, 2007
Revised: August 26, 2007
Accepted: November 19, 2007
Published online: December 21, 2007
Abstract

AIM: To investigate the change in eukaryotic gene expression profile in Caco-2 cells after infection with strains of Escherichia coli and commensal probiotic bacteria.

METHODS: A 19200 gene/expressed sequence tag gene chip was used to examine expression of genes after infection of Caco-2 cells with strains of normal flora E. coli, Lactobacillus plantarum, and a combination of the two.

RESULTS: The cDNA microarray revealed up-regulation of 155 and down-regulation of 177 genes by E. coli. L. plantarum up-regulated 45 and down-regulated 36 genes. During mixed infection, 27 genes were up-regulated and 59 were down-regulated, with nullification of stimulatory/inhibitory effects on most of the genes. Expression of several new genes was noted in this group.

CONCLUSION: The commensal bacterial strains used in this study induced the expression of a large number of genes in colonocyte-like cultured cells and changed the expression of several genes involved in important cellular processes such as regulation of transcription, protein biosynthesis, metabolism, cell adhesion, ubiquitination, and apoptosis. Such changes induced by the presence of probiotic bacteria may shape the physiologic and pathologic responses they trigger in the host.

Keywords: Lactobacillus, Escherichia coli, Gene expression, Probiotic, cDNA microarray