EXPRESSION OF LOW-AFFINITY NGF RECEPTOR AND TRKB MESSENGER-RNA IN HUMAN SH-SY5Y NEUROBLASTOMA-CELLS

We have used the human neuroblastoma cell line SH-SY5Y as a model syst em to investigate the expression and regulation of the receptors for b rain-derived neurotrophic factor (BDNF), a member of the nerve growth factor (NGF) family of neurotrophins. We demonstrate that SH-SY5Y cell s express transcripts encoding the low-affinity NGF receptor (LNGFR) a nd trkB, the signal transducing receptor unit for BDNF. Interaction of BDNF with SH-SY5Y cells increased the transcription of the c-fos gene , showing that these molecules encode functional BDNF receptors. Our f indings that differentiating agents such as retinoids and cAMP analogs increased the expression of LNGFR, but decreased trkB mRNA levels, su ggest that LNGFR and trkB have different roles during neuronal differe ntiation.