Upregulation of CREB1 and FOXO1 transcription factor pathways in Neuregulin-1 mediated neuroprotection following ischemic stroke

Neuregulin-1 (NRG-1) is growth factor that has been investigated for its neuroprotective properties following ischemic stroke. While NRG-1 has shown significant promise in preventing neuronal damage following stroke, the mechanisms behind its neuroprotective effects are unclear. The goal of this research was to investigate the effects of NRG-1 treatment on ischemia-induced gene expression profiles following a permanent middle cerebral artery occlusion (MCAO) in rats. Rats were sacrificed twelve hours following MCAO and either vehicle or NRG-1 treatment. RNA extracted from the peri-infarct cortex of the brain was hybridized to an Affymetrix Rat Genome 2.0st Microarray Gene Chip. Data were analyzed using the Affymetrix Transcriptome Analysis Console (TAC) 4.0 software and the STRING Protein-Protein Interaction Networks database. Our results showed that NRG-1 delivery increased the regulation of pro-survival genes. Most notably, NRG-1 treatment upregulated the CREB1 and FOXO1 transcription factor pathways which are involved in increasing anti-inflammatory and cell proliferation responses and decreasing apoptosis and oxidative stress responses, respectively. Luminex multiplex transcription factor assays demonstrated that the activities of CREB1 and FOXO1 were increased by NRG-1 treatment with MCAO. These findings provide novel insight into the molecular mechanisms involved in NRG-1 mediated neuroprotection.