Journal of neurochemistry
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Journal of neurochemistry · Jan 1997
K-252b potentiation of neurotrophin-3 is trkA specific in cells lacking p75NTR.
K-252b potentiates the neurotrophic effects of neurotrophin-3 (NT-3) in primary cultures of rat central cholinergic and peripheral sensory neurons and in a rat pheochromocytoma PC12 cell line. The ligand and receptor specificity, and role of the low-affinity neurotrophin receptor (p75NTR) in the potentiation response induced by K-252b, are unknown. To address the issues of ligand and receptor specificity of K-252b potentiation, we have examined neurotrophin-induced DNA synthesis ([3H]-thymidine incorporation) in NIH3T3 cells expressing trkA, trkB, or trkC. ⋯ Furthermore, K-252b did not potentiate DNA synthesis by submaximal doses of BDNF, NT-4/5, or NT-3 in trkB- or trkC-expressing NIH3T3 cells, suggesting that the potentiation profile for K-252b was specific for NT-3 in trkA-expressing cells. We found no expression of p75NTR in the trk-expressing NIH3T3 cells. This is the first demonstration that K-252b potentiates a trkA-mediated biological nonneuronal response by NT-3 that occurs independent of p75NTR and appears to be both ligand and receptor specific.