CMX-8933, a peptide fragment of the glycoprotein ependymin, promotes activation of AP-1 transcription factor in mouse neuroblastoma and rat cortical cell cultures

An 8-amino acid peptide fragment (CMX-8933) of Ependymin, a glycoprotein co mponent of the extracellular fluid and cerebrospinal fluid of goldfish brai n, was synthesized and tested for its capacity to activate AP-1 transcripti on factor in cell cultures. Dose-response and time-course studies of AP-1's binding to DNA were carried out in neuroblastoma (NB2a/ dl) and primary ra t brain cortical cultures using an electrophoretic mobility shift assay (EM SA). A 13-14-fold increase in AP-1's DNA binding was obtained when NB2a cel ls were incubated for 4 h with 6-10 mug/ml CMX-8933. Primary rat brain cort ical cultures were much more sensitive to the effects of CMX-8933 than tran sformed (NB2a) cultures; here a 26.7 +/- 5.2-fold increase in binding was o bserved following a 3-h treatment with as little as 10 ng/ml peptide. These findings are consistent with an activation of this transcription factor, a characteristic that has been previously correlated with functional aspects of full-sized neurotrophic factors (nerve growth factor and brain-derived nerve growth factor) in neuronal differentiation and regeneration. Such dat a suggest a role for Ependymin in transcriptional control. (C) 2001 Elsevie r Science Ireland Ltd. All rights reserved.