RT Journal Article
SR Electronic
T1 Differential Activity of the Nerve Growth Factor (NGF) Antagonist PD90780 [7-(Benzolylamino)-4,9-dihydro-4-methyl-9-oxo-pyrazolo[5,1-<em>b</em>]quinazoline-2-carboxylic Acid] Suggests Altered NGF-p75<sup>NTR</sup> Interactions in the Presence of TrkA
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 505
OP 511
DO 10.1124/jpet.104.066225
VO 310
IS 2
A1 Amy Colquhoun
A1 Gail M. Lawrance
A1 Igor L. Shamovsky
A1 Richard J. Riopelle
A1 Gregory M. Ross
YR 2004
UL http://jpet.aspetjournals.org/content/310/2/505.abstract
AB The neurotrophin nerve growth factor (NGF) binds to two receptor types: the tyrosine kinase receptor TrkA and the common neurotrophin receptor p75NTR. Although many of the biological effects of NGF (such as neuronal growth and survival) are associated with TrkA activation, p75NTR also contributes to these activities by enhancing the action of TrkA when receptors are coexpressed. The NGF antagonist PD90780 [7-(benzolylamino)-4,9-dihydro-4-methyl-9-oxo-pyrazolo[5,1-b]quinazoline-2-carboxlic acid] interacts with NGF, preventing its binding to p75NTR. In this study, the actions of this compound are further explored, and it is found that PD90780 is not able to inhibit the binding of either brain-derived neurotrophic factor or neurotrophin-3 to p75NTR, consistent with the direct interactions of the antagonist with NGF. In addition, we demonstrate that the ability of PD90780 to inhibit NGF-p75NTR interactions is lower when receptors are coexpressed, compared with when p75NTR is the only neurotrophin receptor expressed. These results suggest that the interaction between NGF and the p75NTR receptor is altered when TrkA is coexpressed. This alteration can be exploited in the development of antagonists that will selectively inhibit the pro-apoptotic actions of p75NTR when expressed in the absence of TrkA, although having less effect on the pro-survival effects of p75NTR mediated by enhanced TrkA activation. The American Society for Pharmacology and Experimental Therapeutics