Induction of astrocytic nestin expression by depolarization in rats

Nestin is expressed in central nervous system (CNS) progenitor cells and its expression in mature cells represents transition to a less differentiated cellular state under cellular stress. This study was performed to corroborate the hypothesis that nestin synthesis is induced by depolarization and dependent on N-methyl-D-aspartate (NMDA)-receptor activation. Depolarization was induced with application of potassium chloride on the exposed rat cortex and nestin expression was evaluated by immunohistochemistry. Depolarization induced astrocytic nestin expression that was local, or evident in the entire ipsilateral cortex depending on the time of exposure. Nestin expression was NMDA-receptor-dependent since MK-801 treatment abolished the response. Understanding the mechanisms for nestin expression is important since this protein is expressed in reactive and less differentiated CNS cell states and also in neural stem cells. Insights into the control of nestin expression may also provide means for controlling differentiation of CNS cells either post-trauma/ischemia or in transplantation strategies. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.