Retinoic Acid (RA) and Nerve Growth Factor (NGF) induce VGF endogenous expression and promoter activity in SH-SY5Y cells. — ASN Events

Retinoic Acid (RA) and Nerve Growth Factor (NGF) induce VGF endogenous expression and promoter activity in SH-SY5Y cells. (#255)

J E Lewis 1 , P J Hill 1 , J M John 1 , P H Jethwa 1
  1. University of Nottingham, Nottingham, UK

VGF derived peptides, TLQP-21 and HHPD-41, appear to have opposite effects on food intake in Siberian hamsters (Jethwa et al., 2007; Lewis et al., unpublished data), therefore we have used human neuron like cells from the SH-SY5Y neuroblastoma cell line,  a subline of the neuroblastoma cell line SK-N-SH (Hattangady and Rajadhyaksha 2009), to investigate the regulation of VGF gene expression. Firstly, we quantified the effects of retinoic acid (RA) and nerve growth factor (NGF) on SH-SY5Y cell growth and differentiation. As expected NGF stimulated cell proliferation, whereas RA inhibited proliferation and stimulated differentiation. Sequential exposure to RA then NGF induced differentiation further, producing a population of cells with a neuronal morphology. We then investigated whether RA and NGF altered endogenous VGF expression. RA induced VGF expression in differentiating cells (p < 0.001), while NGF induced VGF expression in both proliferating (p < 0.01) and differentiating (p < 0.001) SH-SY5Y cells.  A reporter construct, based on the mammalian expression vector pZsGreen1-1, was designed containing 1Kb of the VGF promoter, including various response elements implicated in tissue-specific expression of neuronal genes (Li et al., 1993). As hypothesised, both RA (p < 0.0001) and NGF (p < 0.0001) increased VGF promoter activity, as well as in combination (p < 0.0001), an effect which was additive (p < 0.01). In conclusion, we have developed the SH-SY5Y cell line for the study of neuronal VGF gene expression in vitro and shown stimulatory effects of RA and NGF on VGF gene expression and promoter activity.