TY - JOUR
T1 - Interferon-γ modulates cAMP-induced mucin exocytosis without affecting mucin gene expression in a human colonic goblet cell line
AU - Jarry, Anne
AU - Merlin, Didier
AU - Velcich, Anna
AU - Hopfer, Ulrich
AU - Augenlicht, Leonard H.
AU - Laboisse, Christian L.
N1 - Funding Information:
We are gratefult o Roussel-Uclaffo r providingu s with interferon-),T. hisw orkw ass upporteidn partb yt heA ssociatioFnr an~aise de Luttec ontrela Mucoviscidos(Ae .F.L.M.),t heA ssociatiopno url a Recherchseu r le Cancer( A.R.C.),the PhilippeF dn, and by grants from NIH (DK39658)a nd the NationalC ancerI nstitute(C A-56081 and P30-CA-1330).
PY - 1994/3/15
Y1 - 1994/3/15
N2 - The regulation of intestinal mucin secretion by cytokines, soluble factors released by mucosal activated immune cells, is so far unknown. The aim of the present study was (1) to investigate the regulatory effects of interferon-γ on baseline and stimulated mucin secretion elicited by an increase in intracellular cAMP, either a short-term increase (induced by vasoactive intestinal peptide or by forskolin) or a long-term increase (cholera toxin-induced), and (2) to attempt to delineate the site of action of interferon-γ. The in vitro model used was the human colonic goblet cell line C1.16E, which has already been shown to respond to physiological secretagogues in terms of mucin secretion. We examined the effects of interferon-γ 1) on mucin exocytosis, measured as release of [3H]glucosamine-labeled macromolecules trapped at the stacking/running gel interface of polyacrylamide gels, and 2) on mucin biosynthesis, examined at the RNA level using a cDNA probe directed to the MUC2 mucin gene. We demonstrated that, while interferon-γ did not alter baseline Cl.16E mucin secretion and MUC2 gene expression, it strongly inhibited the protein kinase A-dependent secretory response to VIP, forskolin, or cholera toxin. However, interferon-γ had no effect on the protein kinase A-dependent MUC2 over-expression induced by cholera toxin. We thus concluded that the target for interferon-γ inhibition of cAMP-stimulated Cl.16E mucin secretion is distal to protein kinase A and might be a component of the exocytotic machinery. Together, our results establish interferon-γ as a pharmacologically powerful tool to specifically inhibit stimulated secretory processes without affecting baseline secretion.
AB - The regulation of intestinal mucin secretion by cytokines, soluble factors released by mucosal activated immune cells, is so far unknown. The aim of the present study was (1) to investigate the regulatory effects of interferon-γ on baseline and stimulated mucin secretion elicited by an increase in intracellular cAMP, either a short-term increase (induced by vasoactive intestinal peptide or by forskolin) or a long-term increase (cholera toxin-induced), and (2) to attempt to delineate the site of action of interferon-γ. The in vitro model used was the human colonic goblet cell line C1.16E, which has already been shown to respond to physiological secretagogues in terms of mucin secretion. We examined the effects of interferon-γ 1) on mucin exocytosis, measured as release of [3H]glucosamine-labeled macromolecules trapped at the stacking/running gel interface of polyacrylamide gels, and 2) on mucin biosynthesis, examined at the RNA level using a cDNA probe directed to the MUC2 mucin gene. We demonstrated that, while interferon-γ did not alter baseline Cl.16E mucin secretion and MUC2 gene expression, it strongly inhibited the protein kinase A-dependent secretory response to VIP, forskolin, or cholera toxin. However, interferon-γ had no effect on the protein kinase A-dependent MUC2 over-expression induced by cholera toxin. We thus concluded that the target for interferon-γ inhibition of cAMP-stimulated Cl.16E mucin secretion is distal to protein kinase A and might be a component of the exocytotic machinery. Together, our results establish interferon-γ as a pharmacologically powerful tool to specifically inhibit stimulated secretory processes without affecting baseline secretion.
KW - Colonic cell line (Human)
KW - Cytokine regulation
KW - Interferon-γ, cAMP
KW - MUC2 mucin gene
KW - Mucus secretion
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U2 - 10.1016/0922-4106(94)90229-1
DO - 10.1016/0922-4106(94)90229-1
M3 - Article
C2 - 7515824
AN - SCOPUS:0028177283
SN - 0922-4106
VL - 267
SP - 95
EP - 103
JO - European Journal of Pharmacology: Molecular Pharmacology
JF - European Journal of Pharmacology: Molecular Pharmacology
IS - 1
ER -