The basic helix-loop-helix (bHLH) superfamily of transcription factors have been implicated in a wide range of cellular functions such as proliferation, differentiation, tumorigenesis, and circadian rhythms. In a previous siRNA-based screen, bHLH family member e41 (BHLHE41) had been identified as a putative regulator of neuronal differentiation; however, its function remains largely elusive. To this end, using the CRISPR-Cas9 system, we established an isogenic Neuro2a (N2a) cell line with biallelic targeting of Bhlhe41 gene (Bhlhe41-/-). In undifferentiated N2a cells, complete knockout of Bhlhe41 resulted in marked proliferation inhibition, together with accumulation of apoptotic cells. Furthermore, retinoic acid (RA)-induced neurite outgrowth and expression of neuronal markers are significantly weakened in Bhlhe41-/- cells. We also showed that the activity of ERK1/2 signaling, a key regulator of neuronal differentiation, is likewise impaired in knockout cells. Together, these results suggest that Bhlhe41 plays critical roles in regulating cell death and neurite outgrowth in N2a cells.
Keywords: Apoptosis; Bhlhe41; ERK1/2 signaling; Neurite outgrowth.