Pioglitazone protects PC12 cells against oxidative stress injury: An in vitro study of its antiapoptotic effects via the PPARγ pathway

To the best of our knowledge, the role of peroxisome proliferator-activated receptor γ (PPARγ) in oxidative stress-induced PC12 cell damage is unknown. Using a PC12 cell model with H(2)O(2) treatment, the present study investigated the expression levels of apoptosis-related genes and neuronal apoptosis after oxidative stress injury. The present study further investigated the protective effect and mechanism of pioglitazone, a PPARγ agonist. PC12 cells treated with H(2)O(2) were used as a model of oxidative stress injury. An MTT assay and flow cytometry were used to detect the effect of H(2)O(2) on PC12 cell viability and the protective effect of pioglitazone. A TUNEL assay was used to detect neuronal apoptosis. The expression levels of PPARγ, Bax, Bcl-2 and caspase-3 were examined by reverse transcription-quantitative PCR and western blotting. H(2)O(2) reduced PC12 cell viability in a dose- and time-dependent manner. H(2)O(2) significantly upregulated the protein expression levels of Bax and the cleaved caspase-3/caspase-3 ratio (P<0.01), decreased the protein expression levels of Bcl-2 (P<0.01), and increased the apoptosis rate of PC12 cells. Pioglitazone significantly reduced the protein expression levels of Bax and the cleaved caspase-3/caspase-3 ratio (P<0.01), increased the expression levels of Bcl-2 (P<0.01), decreased the Bax/Bcl-2 expression ratio (P<0.01) and increased the viability of H(2)O(2)-damaged PC12 cells in a dose-dependent manner. Treatment with the PPARγ antagonist GW9662 or PPARγ small interfering RNA counteracted the protective effect of pioglitazone on PC12 cells to different extents (P<0.01). Therefore, the present study reported the role of PPARγ in protecting PC12 cells against oxidative stress injury, which may lead to novel therapeutic approaches for neurodegenerative diseases.