| First Author | Cherry AD | Year | 2014 |
| Journal | J Biol Chem | Volume | 289 |
| Issue | 1 | Pages | 41-52 |
| PubMed ID | 24253037 | Mgi Jnum | J:207184 |
| Mgi Id | MGI:5554637 | Doi | 10.1074/jbc.M113.512483 |
| Citation | Cherry AD, et al. (2014) Peroxisome proliferator-activated receptor gamma co-activator 1-alpha as a critical co-activator of the murine hepatic oxidative stress response and mitochondrial biogenesis in Staphylococcus aureus sepsis. J Biol Chem 289(1):41-52 |
| abstractText | A key transcriptional regulator of cell metabolism, the peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PPARGC-1-alpha or PGC-1alpha), also regulates mitochondrial biogenesis, but its role in antioxidant gene regulation is not well understood. Here, we asked whether genetic heterozygosity of PGC-1alpha modulates gene expression for the mitochondrial antioxidant enzyme SOD-2 during hepatic inflammatory stress. Using Staphylococcus aureus peritonitis in mice, we found significant Sod2 gene induction in WT mice, whereas PGC-1alpha heterozygotes (PGC-1alpha(+/-)) failed to augment Sod2 mRNA and protein levels. Impaired Sod2 regulation in PGC-1alpha(+/-) mice was accompanied by oxidative stress shown by elevated mitochondrial GSSG/GSH and protein carbonyls. In silico analysis of the mouse proximal Sod2 promoter region revealed consensus binding sites for the Nfe2l2 (Nrf2) transcription factor. Chromatin immunoprecipitation demonstrated diminished Nfe2l2 protein binding to the antioxidant response element promoter site proximal to the Sod2 start site in PGC-1alpha heterozygous mice, implicating PGC-1alpha in facilitation of Nfe2l2 DNA binding. Nuclear protein co-immunoprecipitation demonstrated an interaction between hepatic Nfe2l2 and PGC-1alpha in WT mice that was greatly reduced in PGC-1alpha(+/-) mice. The data indicate that PGC-1alpha promotes mitochondrial antioxidant enzyme expression through Nfe2l2-mediated SOD-2 expression in sepsis. The presence of this new PGC-1alpha-dependent signaling axis indicates that PGC-1alpha opposes mitochondrial oxidative stress by means of selective induction of one or more antioxidant response element-driven genes. By implication, exploitation of this axis could lead to new pharmacological interventions to improve the antioxidant defenses during oxidative stress-induced mitochondrial damage. |
