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Mechanisms of nitric oxide‐induced apoptosis in bovine chromaffin cells: Role of mitochondria and apoptotic proteins
Author(s) -
PérezRodríguez Rocío,
Fuentes María P.,
Oliván Anna M.,
MartínezPalacián Adoración,
Roncero Cesáreo,
González María P.,
OsetGasque María J.
Publication year - 2007
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.21342
Subject(s) - apoptosis , microbiology and biotechnology , cytochrome c , mitochondrion , cytosol , downregulation and upregulation , biology , bcl 2 family , nitric oxide , mitochondrial apoptosis induced channel , programmed cell death , bcl 2 associated x protein , caspase 3 , biochemistry , endocrinology , gene , enzyme
The aim of this work was to establish the possible involvement of mitochondria in the apoptotic event triggered by nitric oxide (NO) in chromaffin cells. Using bovine chromaffin cells in primary culture and several NO donors (SNP, SNAP, and GSNO) at apoptotic concentrations (50 μM–1 mM), we have shown that NO induces a time‐dependent decrease in the mitochondrial transmembrane potential (ΔΨ m ), which correlates with the appearance of hypodiploid cells. Disruption in ΔΨ m is followed by cytochrome c release to the cytosol, which in turn precedes caspase 3 activation. In this mechanism participates the Bcl‐2 protein family, because NO donors downregulate the expression of anti‐apoptotic members of the family such as Bcl‐2 and Bcl‐XL, and increase the expression of pro‐apoptotic members, Bax and Bcl‐Xs, inductors of cytochrome c release to cytosol. Different cell signaling pathways seem to regulate Bax induction and Bcl‐2 inhibition because decreased Bcl‐2 levels are detected later than enhanced Bax expression. The tumour suppressor protein p53 is also upregulated in a very early phase (30 min) of the NO‐induced apoptosis and may be responsible for the further induction of Bax expression. Finally, the translocation of NF‐κB to the nucleus seems to be another early event in NO‐induced apoptosis and it may be involved in the regulation of p53 expression. These results support strongly the participation of mitochondrial mechanisms in NO‐induced apoptosis in chromaffin cells and suggest that these cells may be good models for the investigation of molecular basis of neurodegeneration and neuroprotection. © 2007 Wiley‐Liss, Inc.