Polarized secretion of IL-6 by IEC-6 intestinal epithelial cells: differential effects of IL-1 beta and TNF-alpha.
Intestinal epithelial cells (IEC) can exist as polarized cells and are capable of secreting interleukin-6 (IL-6), yet it has not been determined if this IL-6 is secreted in a polarized fashion. Using the non-transformed rat IEC-6 intestinal epithelial cell line grown on microporous membrane inserts, we have determined that these cells were capable of secreting IL-6 preferentially to the basal surface when stimulated basally with IL-1 beta. In contrast, stimulation of the cells with TNF-alpha resulted in an equal level of IL-6 secretion to the apical and basal surfaces, regardless of whether the cells were stimulated by the apical or basal route. Experiments designed to test the permeability of the IEC-6 cell layer to apically added sodium fluorescein confirmed that neither IL-1 beta nor TNF-alpha altered the integrity of the cell layer after three days. These results suggest that IEC may have the capacity to secret IL-6 in different patterns depending upon the stimulation received. This would allow communication between the IEC and lamina propria cells via basal secretion and rapid communication between IEC via apical secretion.
Mascarenhas
J O
JO
Department of Biological Sciences, Binghamton University (SUNY) 13902-6000, USA.
Goodrich
M E
ME
Eichelberger
H
H
McGee
D W
DW
D000818:Animals; D002460:Cell Line; D016764:Cell Polarity / Q000276:immunology*; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D007375:Interleukin-1 / Q000494:pharmacology*; D015850:Interleukin-6 / Q000378:metabolism*; D007422:Intestines / Q000166:cytology*; D051381:Rats; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha