Endogenous erythropoietin from astrocyte protects the oligodendrocyte precursor cell against hypoxic and reoxygenation injury

• Published in: Journal of neuroscience research Vol. 89; no. 10; pp. 1566 - 1574
• Main Authors: Kato, Shin, Aoyama, Mineyoshi, Kakita, Hiroki, Hida, Hideki, Kato, Ineko, Ito, Tetsuya, Goto, Tatenobu, Hussein, Mohamed H., Sawamoto, Kazunobu, Togari, Hajime, Asai, Kiyofumi
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.10.2011
• Subjects: Animals; Animals, Newborn; astrocyte; Astrocytes; Astrocytes - metabolism; Astrocytes - physiology; Brain; Cell Hypoxia - genetics; Cell Hypoxia - physiology; Cell survival; Cell Survival - genetics; Cytokines; Cytoprotection - physiology; Enzyme-linked immunosorbent assay; Erythropoietin; Erythropoietin - genetics; Erythropoietin - physiology; Erythropoietin receptors; Gene silencing; Glial stem cells; Hypoxia; Hypoxia, Brain - pathology; Hypoxia, Brain - physiopathology; Hypoxia, Brain - prevention & control; hypoxic/reoxygenation; Injuries; Ischemia; Mice; Mice, Inbred ICR; Microglia; Nervous system; Neurodegenerative diseases; Neuroprotection; oligodendrocyte precursor cell; Oligodendroglia - cytology; Oligodendroglia - metabolism; Oligodendroglia - pathology; Oxidative Stress - genetics; Polymerase chain reaction; Primary Cell Culture; Receptors, Erythropoietin - genetics; Receptors, Erythropoietin - physiology; RNA, Small Interfering - physiology; siRNA; Stem Cells - cytology; Stem Cells - metabolism; Stem Cells - pathology; Stress
• ISSN: 0360-4012; 1097-4547; 1097-4547
• DOI: 10.1002/jnr.22702

The hypoxia‐responsive cytokine erythropoietin (EPO) provides neuroprotective effects in the damaged brain during ischemic events and neurodegenerative diseases. The purpose of the present study is to evaluate the EPO/EPO receptor (EPOR) endogenous system between astrocyte and oligodendrocyte precursor cell (OPC) under hypoxia. We report here elevated EPO mRNA levels and protein release in cultured astrocytes following hypoxic stimulation by quantitative RT‐PCR and ELISA. Furthermore, the EPOR gene expressions were detected in cultured OPCs as in astrocytes and microglias by quantitative RT‐PCR. Cell staining revealed the EPOR expression in OPC. To evaluate the protective effect of endogenous EPO from astrocyte to OPCs, EPO/EPOR signaling was blocked by EPO siRNA or EPOR siRNA gene silencing in in vitro study. The suppression of endogenous EPO production in astrocytes by EPO siRNA decreased the protection to OPCs against hypoxic stress. Furthermore, OPC with EPOR siRNA had less cell survival after hypoxic/reoxygenation injury. This suggested that EPO/EPOR signaling from astrocyte to OPC could prevent OPC damage under hypoxic/reoxygenation condition. Our present finding of an interaction between astrocytes and OPCs may lead to a new therapeutic approach to OPCs for use against cellular stress and injury. © 2011 Wiley‐Liss, Inc.