Preferential activation of HIF-2α adaptive signalling in neuronal-like cells in response to acute hypoxia

Mart�n-Arag�n Baudel, Miguel A. S.; Rae, Mick T.; Darlison, Mark G.; Poole, Amy V.; Fraser, Jennifer A.

Abstract

Stroke causes severe neuronal damage as disrupted cerebral blood flow starves neurons of oxygen and glucose. The hypoxia inducible factors (HIF-1α and HIF-2α) orchestrate oxygen homeostasis and regulate specific aspects of hypoxic adaptation. Here we show the importance of HIF-2α dependant signalling in neuronal adaptation to hypoxic insult. PC12 and NT2 cells were differentiated into neuronal-like cells using NGF and retinoic acid, and exposed to acute hypoxia (1% O2). Gene and protein expression was analysed by qPCR and immunoblotting and the neuronal-like phenotype was examined. PC12 and NT2 differentiation promoted neurite extension and expression of neuronal markers, NSE and KCC2. Induction of HIF-1α mRNA or protein was not detected in hypoxic neuronal-like cells, however marked induction of HIF-2α mRNA and protein expression was observed. Induction of HIF-1α target genes was also not detected in response to acute hypoxia, however significant induction of HIF-2α transcriptional targets was clearly evident. Furthermore, hypoxic insult dramatically reduced both neurite number and length, and attenuated expression of neuronal markers, NSE and KCC2. This correlated with an increase in expression of the neural progenitor and stem cell-like markers, CD44 and vimentin, suggesting HIF-2α molecular mechanisms could potentially promote regression of neuronal-like cells to a stem-like state and trigger neuronal recovery following ischaemic insult. Our findings suggest the HIF-2α pathway predominates over HIF-1α signalling in neuronal-like cells following acute hypoxia.

Citation

Martín-Aragón Baudel, M. A. S., Rae, M. T., Darlison, M. G., Poole, A. V., & Fraser, J. A. (2017). Preferential activation of HIF-2α adaptive signalling in neuronal-like cells in response to acute hypoxia. PLOS ONE, 12(10), Article e0185664. https://doi.org/10.1371/journal.pone.0185664

• Journal Article Type: Article
• Acceptance Date: Sep 22, 2017
• Online Publication Date: Oct 2, 2017
• Publication Date: Oct 2, 2017
• Deposit Date: Sep 27, 2017
• Publicly Available Date: Oct 3, 2017
• Journal: PLoS ONE
• Print ISSN: 1932-6203
• Publisher: Public Library of Science
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 10
• Article Number: e0185664
• DOI: https://doi.org/10.1371/journal.pone.0185664
• Keywords: Stroke, acute hypoxia, neuronal adaptation,
• Public URL: http://researchrepository.napier.ac.uk/Output/991388
• Contract Date: Oct 3, 2017