Article date: December 2000
By: D Hamish Wright, Anthony W Ford‐Hutchinson, Kris Chadee, Kathleen M Metters in Volume 131, Issue 8, pages 1537-1545
This study demonstrates the localization of the prostaglandin (PG)D2 receptor (DP) within the mucous‐secreting globlet cells of the human colon by in situ hybridization, which suggests a role for DP in mucous secretion. Selective high affinity ligands were used, therefore, to evaluate DP regulation of mucous secretion in LS174T human colonic adenocarcinoma cells.
The expression of hDP in LS174T cells was confirmed at the mRNA level by reverse transcriptase‐polymerase chain reaction, and at the protein level by radioligand binding assays and signal transduction (cyclic AMP accumulation) assays. PGD2 and the highly selective DP‐specific agonist L‐644,698 ((4‐(3‐(3‐(3‐hydroxyoctyl)‐4‐oxo‐2‐thiazolidinyl) propyl) benzoic acid) (racemate)), but not PGE2 competed for [3H]‐PGD2‐specific binding to LS174T cell membranes (Ki values of 0.4 nM and 7 nM, respectively). The DP‐specific agonists PGD2, PGJ2, BW245C (5‐(6‐carboxyhexyl)‐1‐(3‐cyclohexyl‐3‐hydroxypropylhydantoin)), and L‐644,698 showed similar potencies in stimulating cyclic AMP accumulation (EC50 values: 45–90 nM) and demonstrated the expected rank order of potency. PGE2 also elicited cyclic AMP production in this cell line (EC50 value: 162 nM).
The activation of cyclic AMP production by PGD2 and L‐644,698, but not PGE2, was inhibited by the selective DP antagonist BW A868C. Thus, PGD2 and L‐644,698 act through hDP in LS174T cells. PGD2, L‐644,698 and PGE2 (an established mucin secretagogue) potently stimulated mucin secretion in LS174T cells in a concentration‐dependent manner (EC50<50 nM). However, BW A868C effectively antagonized only the mucin secretion mediated by PGD2 and L‐644,698 and not PGE2. These data support a role for the DP receptor in the regulation of mucous secretion.
This study demonstrates the localization of the prostaglandin (PG)D2 receptor (DP) within the mucous‐secreting globlet cells of the human colon by in situ hybridization, which suggests a role for DP in mucous secretion. Selective high affinity ligands were used, therefore, to evaluate DP regulation of mucous secretion in LS174T human colonic adenocarcinoma cells.
The expression of hDP in LS174T cells was confirmed at the mRNA level by reverse transcriptase‐polymerase chain reaction, and at the protein level by radioligand binding assays and signal transduction (cyclic AMP accumulation) assays. PGD2 and the highly selective DP‐specific agonist L‐644,698 ((4‐(3‐(3‐(3‐hydroxyoctyl)‐4‐oxo‐2‐thiazolidinyl) propyl) benzoic acid) (racemate)), but not PGE2 competed for [3H]‐PGD2‐specific binding to LS174T cell membranes (Ki values of 0.4 nM and 7 nM, respectively). The DP‐specific agonists PGD2, PGJ2, BW245C (5‐(6‐carboxyhexyl)‐1‐(3‐cyclohexyl‐3‐hydroxypropylhydantoin)), and L‐644,698 showed similar potencies in stimulating cyclic AMP accumulation (EC50 values: 45–90 nM) and demonstrated the expected rank order of potency. PGE2 also elicited cyclic AMP production in this cell line (EC50 value: 162 nM).
The activation of cyclic AMP production by PGD2 and L‐644,698, but not PGE2, was inhibited by the selective DP antagonist BW A868C. Thus, PGD2 and L‐644,698 act through hDP in LS174T cells. PGD2, L‐644,698 and PGE2 (an established mucin secretagogue) potently stimulated mucin secretion in LS174T cells in a concentration‐dependent manner (EC50<50 nM). However, BW A868C effectively antagonized only the mucin secretion mediated by PGD2 and L‐644,698 and not PGE2. These data support a role for the DP receptor in the regulation of mucous secretion.
British Journal of Pharmacology (2000) 131, 1537–1545; doi:10.1038/sj.bjp.0703688
DOI: 10.1038/sj.bjp.0703688
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