NDRG2 is a novel p53-associated regulator of apoptosis in C6-originated astrocytes exposed to oxygen-glucose deprivation

PLoS One. 2013;8(2):e57130. doi: 10.1371/journal.pone.0057130. Epub 2013 Feb 22.

Abstract

N-myc downstream-regulated gene 2 (NDRG2) has been documented to be a pro-differentiative and anti-proliferative gene in cancer research. Our previous study found a significant NDRG2 up-regulation in reactive astrocytes of penumbra after transient focal cerebral ischemia, which was parallel to the enhancement of TUNEL-positive signals. However, it is still uncertain whether NDRG2 participates in cellular apoptosis induced by ischemia-reperfusion injury in brain. In this study, we investigated the role of NDRG2 in cellular apoptosis induced by oxygen-glucose deprivation (OGD) in IL-6-differentiated C6 glioma cells. The results showed that NDRG2 was up-regulated and translocated from the cytoplasm to the nucleus after OGD exposure. NDRG2 over-expression exhibited an anti-proliferative effect and increased the Bax/Bcl-2 ratio after OGD exposure, while NDRG2 silencing promoted the cellular proliferation and attenuated the up-regulation of Bax/Bcl-2 ratio. The pro-apoptotic effect of p53 was verified by the results in which p53 silencing greatly reduced the percentage of OGD-induced apoptotic cells. p53 silencing also reduced the OGD-induced NDRG2 up-regulation. However, over-expression of p53 did not further improve the NDRG2 up-regulation. In conclusion, NDRG2 is a p53-associated regulator of apoptosis in C6-originated astrocytes after OGD exposure. These findings bring insight to the roles of NDRG2 in ischemic-hypoxic injury and provide potential targets for future clinical therapies on stroke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / physiology*
  • Astrocytes / metabolism*
  • Astrocytes / pathology
  • Cell Line, Tumor
  • Glucose / metabolism*
  • Humans
  • Oxygen / metabolism*
  • Tumor Suppressor Protein p53 / physiology*
  • Tumor Suppressor Proteins / physiology*

Substances

  • NDRG2 protein, human
  • Tumor Suppressor Protein p53
  • Tumor Suppressor Proteins
  • Glucose
  • Oxygen

Grants and funding

This work was supported by the Major Program of National Natural Science Foundation of China (No. 30930091), and the National Natural Science Foundation of China (No. 81072888, No. 81071060, No.81000563 and No. 30900462). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.