Journal article
Erythropoietin Inhibits HIF-1 alpha Expression via Upregulation of PHD-2 Transcription and Translation in an In Vitro Model of Hypoxia-Ischemia
Translational stroke research, Vol.5(1), pp.118-127
02/01/2014
DOI: 10.1007/s12975-013-0312-z
PMCID: PMC3946340
PMID: 24323731
Abstract
Hypoxia inducible factor (HIF)-1 alpha is the central transcriptional factor for the regulation of oxygen-associated genes in response to hypoxia. Erythropoietin (EPO), a hematopoietic growth factor, increases oxygen availability during hypoxia/ischemia and is associated with neuroprotection following hypoxia-ischemia in laboratory models of stroke. However, EPO has failed to translate in a clinical setting. Thus, it is critical to elucidate the key players in EPO-induced neuroprotection. Our preliminary studies have shown that EPO, as a downstream gene of HIF, inhibits HIF-1 alpha in a dose-dependent manner in an in vitro model of hypoxia-ischemia. This study is designed to elucidate the primary mediator of EPO-induced HIF-1 alpha inhibition and subsequent cell survival/neuroprotection. Oxygen and glucose deprivation (OGD) of nerve growth factor-differentiated rat pheochromocytoma (PC-12) cells were used to model hypoxia-ischemia in an in vitro environment. The profile of HIF-1 alpha, HIF-2 alpha and prolyl hydroxylase domain 2 (PHD-2) expression; HIF-1 alpha and prolyl hydroxylase (PHD-2) mRNA levels; matrix metalloproteinase (MMP)-9; and cell death was evaluated in the presence and absence of either EPO or PHD-2 inhibitor during OGD. Our findings showed that EPO treatment resulted in an increase in PHD-2 transcription and translation, inhibition of HIF-1 alpha expression, reactive oxygen species formation, and MMP-9 activity, resulting in increased cell survival after OGD. We also observed that EPO-induced cell survival/neuroprotection was reversed by siRNA silencing of PHD-2. This led to the conclusion that PHD-2 is a key mediator of EPO-induced HIF-1 alpha inhibition and subsequent neuroprotection in an in vitro model of hypoxia-ischemia.
Details
- Title: Subtitle
- Erythropoietin Inhibits HIF-1 alpha Expression via Upregulation of PHD-2 Transcription and Translation in an In Vitro Model of Hypoxia-Ischemia
- Creators
- Rhonda Souvenir - Loma Linda UniversityJerry J. Flores - Loma Linda UniversityRobert P. Ostrowski - Loma Linda UniversityAnatol Manaenko - Loma Linda UniversityKamil Duris - Loma Linda UniversityJiping Tang - Loma Linda University
- Resource Type
- Journal article
- Publication Details
- Translational stroke research, Vol.5(1), pp.118-127
- DOI
- 10.1007/s12975-013-0312-z
- PMID
- 24323731
- PMCID
- PMC3946340
- NLM abbreviation
- Transl Stroke Res
- ISSN
- 1868-4483
- eISSN
- 1868-601X
- Publisher
- Springer Nature
- Number of pages
- 10
- Grant note
- NS060936 / NIH; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA R01NS060936 / NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Institute of Neurological Disorders & Stroke (NINDS)
- Language
- English
- Date published
- 02/01/2014
- Academic Unit
- Endocrinology and Metabolism; Internal Medicine
- Record Identifier
- 9984359898902771
Metrics
16 Record Views