Antisense oligonucleotide to NOR-1, a novel orphan nuclear receptor, induces migration and neurite extension of cultured forebrain cells

We previously identified a novel orphan nuclear receptor referred to as NOR-1 from rat forebrain cells. This study examined the role of NOR-1 in primary cultured forebrain cells by selectively inhibiting NOR-1 expression by addition of antisense oligonucleotide to the culture media. Treating cells with the antisense oligomer resulted in the following dramatic morphological changes: (i) cell migration, (ii) extension of processes, and (iii) formation of cellular aggregates. Immunocytochemistry for microtubule-associated protein 2 revealed that the processes were filled with neurites growing from neuronal cells. These findings suggest that NOR-1 may be involved in the molecular mechanisms regulating neural differentiation.

Molecular cloning of a novel thyroid/steroid receptor superfamily gene from cultured rat neuronal cells

Brain neuronal cells in primary culture provide one system for the analysis of neuronal development, including apoptosis. By PCR amplification, with primers designed from conserved sequences among nuclear receptors, a novel member of the thyroid/steroid receptor superfamily was identified from forebrain neuronal cells undergoing apoptosis and designated as NOR-1 (neuron derived orphan receptor). A cDNA clone of NOR-1 encodes a 68kDa, 628 amino acid residue-containing protein, with an amino acid sequence highly homologous to the Nur77 family in its DNA-binding domain and moderately so in its putative ligand-binding domain. Using mobility shift assay, we showed that the NOR-1 protein binds to the B1a response-element which has been identified as the target sequence of the Nur77 family, suggesting that three members of the Nur77 family may transactivate common target gene(s) at different situations.