Expression of cytokine and chemokine mRNA and secretion of tumor necrosis factor-alpha by gallbladder epithelial cells: response to bacterial lipopolysaccharides.
BACKGROUND
In addition to immune cells, many other cell types are known to produce cytokines. Cultured normal mouse gallbladder epithelial cells, used as a model system for gallbladder epithelium, were examined for their ability to express the mRNA of various cytokines and chemokines in response to bacterial lipopolysaccharide. The synthesis and secretion of the tumor necrosis factor-alpha (TNF-alpha) protein by these cells was also measured.


RESULTS
Untreated mouse gallbladder cells expressed mRNA for TNF-alpha, RANTES, and macrophage inflammatory protein-2 (MIP-2). Upon treatment with lipopolysaccharide, these cells now produced mRNA for Interleukin-1beta (IL-1beta), IL-6, monocyte chemoattractant protein-1 (MCP-1), and showed increased expression of TNF-alpha and MIP-2 mRNA. Untreated mouse gallbladder cells did not synthesize TNF-alpha protein; however, they did synthesize and secrete TNF-alpha upon treatment with lipopolysaccharide.


METHODS
Cells were treated with lipopolysaccharides from 3 strains of bacteria. Qualitative and semi-quantitative RT-PCR, using cytokine or chemokine-specific primers, was used to measure mRNA levels of TNFalpha, IL-1beta, IL-6, IL-10, KC, RANTES, MCP-1, and MIP-2. TNF-alpha protein was measured by immunoassays.


CONCLUSIONS
This research demonstrates that gallbladder epithelial cells in response to lipopolysaccharide exposure can alter their cytokine and chemokine RNA expression pattern and can synthesize and secrete TNFalpha protein. This suggests a mechanism whereby gallbladder epithelial cells in vivo may mediate gallbladder secretory function, inflammation and diseases in an autocrine/paracrine fashion by producing and secreting cytokines and/or chemokines during sepsis.
Savard
Christopher E
CE
Department of Medicine, University of Washington and VA Puget Sound Health Care System, Seattle, Washington, USA.
Blinman
Thane A
TA
Choi
Ho-Soon
HS
Lee
Sung-Koo
SK
Pandol
Stephen J
SJ
Lee
Sum P
SP
D000818:Animals; D002478:Cells, Cultured; D018925:Chemokines / Q000096:biosynthesis* / Q000235:genetics; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D003720:Densitometry; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology; D005704:Gallbladder / Q000166:cytology* / Q000187:drug effects*; D006801:Humans; D007118:Immunoassay; D008070:Lipopolysaccharides / Q000494:pharmacology*; D051379:Mice; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000378:metabolism*
D018925:Chemokines; D016207:Cytokines; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha