Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2006-3-22
pubmed:abstractText
Chemoattractant receptor-homologous molecule expressed on T helper 2 cells (CRTH2) has attracted interest as a potential therapeutic target in inflammatory diseases. Ramatroban, a thromboxane A2 receptor antagonist with clinical efficacy in allergic rhinitis, was recently found to also display potent CRTH2 antagonistic activity. Here, we present the pharmacological profile of three ramatroban analogs that differ chemically from ramatroban by either a single additional methyl group (TM30642), or an acetic acid instead of a propionic acid side chain (TM30643), or both modifications (TM30089). All three compounds bound to human CRTH2 stably expressed in human embryonic kidney 293 cells with nanomolar affinity. [3H]Prostaglandin D2 (PGD2) saturation analysis reveals that ramatroban and TM30642 decrease PGD2 affinity, whereas TM30643 and TM30089 exclusively depress ligand binding capacity (Bmax). Each of the three compounds acted as potent CRTH2 antagonists, yet the nature of their antagonism differed markedly. In functional assays measuring inhibition of PGD2-mediated 1) guanosine 5'-O-(3-thio)triphosphate binding, 2) beta-arrestin translocation, and 3) shape change of human eosinophils endogenously expressing CRTH2, ramatroban, and TM30642 produced surmountable antagonism and parallel rightward shifts of the PGD2 concentration-response curves. For TM30643 and TM30089, this shift was accompanied by a progressive reduction of maximal response. Binding analyses indicated that the functional insurmountability of TM30643 and TM30089 was probably related to long-lasting CRTH2 inhibition mediated via the orthosteric site of the receptor. A mechanistic understanding of insurmountability of CRTH2 antagonists could be fundamental for development of this novel class of anti-inflammatory drugs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0026-895X
pubmed:author
pubmed:issnType
Print
pubmed:volume
69
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1441-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
On the mechanism of interaction of potent surmountable and insurmountable antagonists with the prostaglandin D2 receptor CRTH2.
pubmed:affiliation
7TM Pharma A/S, Fremtidsvej 3, 2970 Hørsholm, Denmark.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't