TY - JOUR
T1 - Cytoplasmic p53 and activated bax regulate p53-dependent, transcription-independent neural precursor cell apoptosis
AU - Geng, Ying
AU - Walls, K. C.
AU - Ghosh, Arindam P.
AU - Akhtar, Rizwan S.
AU - Klocke, Barbara J.
AU - Roth, Kevin A.
PY - 2010/3
Y1 - 2010/3
N2 - The prodeath effects of p53 are typically mediated via its transcriptional upregulation of proapoptotic Bcl-2 family members, including PUMA, Noxa, and/or Bax. We previously reported that staurosporine (STS), a broad-spectrum kinase inhibitor and prototypical apoptosis-inducing agent, produced p53-dependent, Bax-dependent, neural precursor cell (NPC) apoptosis, but that this effect occurred independently of new gene transcription and PUMA expression. To further characterize the mechanism by which p53 regulates NPC death, we used primary cerebellar NPCs derived from wild-type, p53-deficient, and Bax-deficient neonatal mice and the mouse cerebellar neural stem cell line, C17.2. We found that STS rapidly increased p53 cytoplasmic immunoreactivity in neuritic-like processes in C17.2 cells, which preceded Bax activation and caspase-3 cleavage. Confocal microscopy analysis of STS-treated cells revealed partial colocalization of p53 with the mitochondrial marker pyruvate dehydrogenase as well as with conformationally altered "activated" Bax, suggesting an interaction between these proapoptotic molecules in triggering apoptotic death. Nucleophosmin (NPM), a CRM1-dependent nuclear chaperone, also exhibited partial colocalization with both activated Bax and p53 following STS treatment. These observations suggest that cytoplasmic p53 can trigger transcription-independent NPC apoptosis through its potential interaction with NPM and activated Bax.
AB - The prodeath effects of p53 are typically mediated via its transcriptional upregulation of proapoptotic Bcl-2 family members, including PUMA, Noxa, and/or Bax. We previously reported that staurosporine (STS), a broad-spectrum kinase inhibitor and prototypical apoptosis-inducing agent, produced p53-dependent, Bax-dependent, neural precursor cell (NPC) apoptosis, but that this effect occurred independently of new gene transcription and PUMA expression. To further characterize the mechanism by which p53 regulates NPC death, we used primary cerebellar NPCs derived from wild-type, p53-deficient, and Bax-deficient neonatal mice and the mouse cerebellar neural stem cell line, C17.2. We found that STS rapidly increased p53 cytoplasmic immunoreactivity in neuritic-like processes in C17.2 cells, which preceded Bax activation and caspase-3 cleavage. Confocal microscopy analysis of STS-treated cells revealed partial colocalization of p53 with the mitochondrial marker pyruvate dehydrogenase as well as with conformationally altered "activated" Bax, suggesting an interaction between these proapoptotic molecules in triggering apoptotic death. Nucleophosmin (NPM), a CRM1-dependent nuclear chaperone, also exhibited partial colocalization with both activated Bax and p53 following STS treatment. These observations suggest that cytoplasmic p53 can trigger transcription-independent NPC apoptosis through its potential interaction with NPM and activated Bax.
KW - Apoptosis
KW - Bax
KW - CRM1
KW - Neural precursor cells
KW - Nucleophosmin
KW - p53
UR - http://www.scopus.com/inward/record.url?scp=77649246037&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77649246037&partnerID=8YFLogxK
U2 - 10.1369/jhc.2009.954024
DO - 10.1369/jhc.2009.954024
M3 - Article
C2 - 19901272
AN - SCOPUS:77649246037
VL - 58
SP - 265
EP - 275
JO - Journal of Histochemistry and Cytochemistry
JF - Journal of Histochemistry and Cytochemistry
SN - 0022-1554
IS - 3
ER -