TY - JOUR
T1 - NF-κB p50/RelA and c-Rel-containing dimers: Opposite regulators of neuron vulnerability to ischaemia
AU - Sarnico, Ilenia
AU - Lanzillotta, Annamaria
AU - Boroni, Flora
AU - Benarese, Marina
AU - Alghisi, Manuela
AU - Schwaninger, Markus
AU - Inta, Ioana
AU - Battistin, Leontino
AU - Spano, Pier Franco
AU - Pizzi, Marina
PY - 2009/1/1
Y1 - 2009/1/1
N2 - Diverse nuclear factor-κB subunits mediate opposite effects of extracellular signals on neuron survival. While RelA is activated by neurotoxic agents, c-Rel drives neuroprotective effects. In brain ischaemia RelA and p50 factors rapidly activate, but how they associate with c-Rel to form active dimers and contribute to the changes in diverse dimer activation for neuron susceptibility is unknown. We show that in both cortical neurons exposed to oxygen glucose deprivation (OGD) and mice subjected to brain ischaemia, activation of p50/RelA was associated with inhibition of c-Rel/RelA dimer and no change p50/c-Rel. Targeting c-Rel and RelA expression revealed that c-Rel dimers reduced while p50/RelA enhanced neuronal susceptibility to anoxia. Activation of p50/RelA complex is known to induce the pro-apoptotic Bim and Noxa genes. We now show that c-Rel-containing dimers, p50/c-Rel and RelA/c-Rel, but not p50/RelA, promoted Bcl-xL transcription. Accordingly, the OGD exposure induced Bim, but reduced Bcl-xL promoter activity and decreased the content of endogenous Bcl-xL protein. These findings demonstrate that within the same neuronal cell, the balance between activation of p50/RelA and c-Rel-containing complexes fine tunes the threshold of neuron vulnerability to the ischaemic insult. Selective targeting of different dimers will unravel new approaches to limit ischaemia-associated apoptosis.
AB - Diverse nuclear factor-κB subunits mediate opposite effects of extracellular signals on neuron survival. While RelA is activated by neurotoxic agents, c-Rel drives neuroprotective effects. In brain ischaemia RelA and p50 factors rapidly activate, but how they associate with c-Rel to form active dimers and contribute to the changes in diverse dimer activation for neuron susceptibility is unknown. We show that in both cortical neurons exposed to oxygen glucose deprivation (OGD) and mice subjected to brain ischaemia, activation of p50/RelA was associated with inhibition of c-Rel/RelA dimer and no change p50/c-Rel. Targeting c-Rel and RelA expression revealed that c-Rel dimers reduced while p50/RelA enhanced neuronal susceptibility to anoxia. Activation of p50/RelA complex is known to induce the pro-apoptotic Bim and Noxa genes. We now show that c-Rel-containing dimers, p50/c-Rel and RelA/c-Rel, but not p50/RelA, promoted Bcl-xL transcription. Accordingly, the OGD exposure induced Bim, but reduced Bcl-xL promoter activity and decreased the content of endogenous Bcl-xL protein. These findings demonstrate that within the same neuronal cell, the balance between activation of p50/RelA and c-Rel-containing complexes fine tunes the threshold of neuron vulnerability to the ischaemic insult. Selective targeting of different dimers will unravel new approaches to limit ischaemia-associated apoptosis.
UR - http://www.scopus.com/inward/record.url?scp=57549112366&partnerID=8YFLogxK
U2 - 10.1111/j.1471-4159.2008.05783.x
DO - 10.1111/j.1471-4159.2008.05783.x
M3 - Journal articles
C2 - 19094066
AN - SCOPUS:57549112366
SN - 0022-3042
VL - 108
SP - 475
EP - 485
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
IS - 2
ER -