CREB1 was also found to be upregulated in human NB tissues, its expression being inversely correlated with miR-205 expression (<i>r</i> = -0.554, <i>p</i> = 0.003).
Twincretin is herein shown to have activity at two different receptors, dose-dependently increase levels of intermediates in the neurotrophic CREB pathway and enhance viability of human neuroblastoma cells exposed to toxic concentrations of glutamate and hydrogen peroxide, insults mimicking the inflammatory conditions in the brain post-mTBI.
This interaction is functional; overexpression of FTO delays the dephosphorylation of cAMP response element-binding protein (CREB) in human neuroblastoma (SK-N-SH) cells, which in turn leads to a dramatic increase in the expression of the CREB targets neuropeptide receptor 1 (NPY1R) and brain-derived neurotrophic factor (BDNF), which already are known to regulate food intake and energy homeostasis.
In the present study, we demonstrate that exposure of human neuroblastoma cells SH-SY5Y to HIV transactivator protein Tat resulted in decreased intrinsic expression of PDGF-CC as evidenced by RT-PCR and western blot assays.
The main target for induction of cyclin D1 transcription by oncogenic ras in neuroblastoma cells is a cyclic AMP response element (CRE) located in proximal promoter sequences, and T3 represses the transcriptional activity of b-Zip transcription factors such as CREB (CRE-binding protein) or ATF-2 (activation transcription factor 2) that are direct targets of Rsk2 and bind to this sequence.