RT Journal Article
SR Electronic
T1 Mitochondrial DNA Damage Level Determines Neural Stem Cell Differentiation Fate
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 9746
OP 9751
DO 10.1523/JNEUROSCI.0852-11.2011
VO 31
IS 26
A1 Wei Wang
A1 Ying Esbensen
A1 David Kunke
A1 Rajikala Suganthan
A1 Lyudmila Rachek
A1 Magnar Bjørås
A1 Lars Eide
YR 2011
UL http://www.jneurosci.org/content/31/26/9746.abstract
AB The mitochondrial DNA (mtDNA) of neural stem cells (NSCs) is vulnerable to oxidation damage. Subtle manipulations of the cellular redox state affect mtDNA integrity in addition to regulating the NSC differentiation lineage, suggesting a molecular link between mtDNA integrity and regulation of differentiation. Here we show that 8-oxoguanine DNA glycosylase (OGG1) is essential for repair of mtDNA damage and NSC viability during mitochondrial oxidative stress. Differentiating neural cells from ogg1−/− knock-out mice spontaneously accumulate mtDNA damage and concomitantly shift their differentiation direction toward an astrocytic lineage, similar to wt NSCs subjected to mtDNA damaging insults. Antioxidant treatments reversed mtDNA damage accumulation and separately increased neurogenesis in ogg1−/− cells. NSCs from a transgenic ogg1−/− mouse expressing mitochondrially targeted human OGG1 were protected from mtDNA damage during differentiation, and displayed elevated neurogenesis. The underlying mechanisms for this shift in differentiation direction involve the astrogenesis promoting Sirt1 via an increased NAD/NADH ratio in ogg1−/− cells. Redox manipulations to alter mtDNA damage level correspondingly activated Sirt1 in both cell types. Our results demonstrate for the first time the interdependence between mtDNA integrity and NSC differentiation fate, suggesting that mtDNA damage is the primary signal for the elevated astrogliosis and lack of neurogenesis seen during repair of neuronal injury.