Neuroprotective effects of neuregulin-1 ß on oligodendrocyte type 2 astrocyte progenitors following oxygen and glucose deprivation.

BACKGROUND

Hypoxic-ischemic brain injury in neonates, especially in premature infants, is one of the main contributors to the mortality of newborns and can cause nervous system dysfunction in children. The major pathogenesis seems to be cerebral ischemia/reperfusion in the immature white matter that preferentially targets vulnerable premyelinating oligodendrocytes.

OBJECTIVES

The goal of this study was to culture oligodendrocyte type 2 astrocyte cells in an oxygen and glucose deprivation environment to simulate ischemia injury and examine the cellular and molecular mechanisms involved in the neuroprotective effects of neuregulin-1ß on ischemia-induced immature oligodendrocytes.

METHODS

Oligodendrocyte type 2 astrocyte cells were cultured from neonatal Sprague-Dawley rat cerebra. The cells were divided into two groups: one was subjected to oxygen and glucose deprivation for 9 hours and the other was treated with 50 ng/mL or 100 ng/mL neuregulin-1β during oxygen and glucose deprivation. Cell survival was determined by Trypan Blue staining and cell apoptosis were observed by fluorescein isothiocyanate-Annexin V and propidium iodide double staining. To study if the PI3K-Akt signaling pathway was involved in the mechanism of protective effect of neuregulin-1ß, Western blot analysis was used to quantitative the changes of protein.

RESULTS

Treatment with neuregulin-1ß within the period of oxygen and glucose deprivation significantly increased cell survival and also resulted in a significant decrease in cell apoptosis. The neuroprotective effects of neuregulin-1ß were prevented by treatment with Ly294002, an inhibitor of the phosphatidylinositol-3-kinase/Akt pathway.

CONCLUSIONS

These results suggest that neuregulin-1ß could protect the oligodendrocyte type 2 astrocyte progenitors against hypoxic injury, and the mechanism may be associated with the PI3K-Akt signaling pathway.