Resveratrol protects PC12 cells against OGD/R-induced apoptosis via the mitochondrial-mediated signaling pathway

Abstract

In this study, we investigated the neuroprotective potential of resveratrol against oxygen glucose deprivation/reoxygenation (OGD/R)-induced apoptotic damages in well-differentiated PC12 cells and the underlying mechanisms. Cells were incubated under normal condition or OGD/R in the presence or absence of 10 μM resveratrol. Cell viability was determined with methyl-thiazolyl-tetrazolium (MTT) assay. Apoptotic ratio was determined with Hoechst 33342 staining and Annexin V-FITC/PI double staining. Oxidative stress was evaluated by measuring the intracellular reactive oxygen species (ROS), the mitochondrial superoxide, the malondialdehyde (MDA) content, and the activities of superoxide dismutase (SOD) and catalase (CAT). The intracellular calcium ([Ca ²⁺]i) was estimated by Fluo-3/AM. The mitochondrial membrane potential (MMP) was evaluated by 5,5′,6,6′-tetrachloro-1,1,3,3′-tetraethyl-benzimidazolyl-carbocyanine iodide (JC-1) and rhodamine 123 (Rh123). The opening of mitochondrial permeability transition pore (MPTP) was determined by the Calcein/Co ²⁺-quenching technique. The protein levels of cytochrome c, Bcl-2, Bax, cleaved caspase-9, and cleaved caspase-3 were detected by western blot analysis. The results showed that 10 μM resveratrol attenuated OGD/R-induced cell viability loss and cell apoptosis, which was associated with the decreases in the MDA content and the increases in the SOD and CAT activities. Furthermore, the accumulation of intracellular ROS and mitochondrial superoxide, disturbance of [Ca ²⁺]i homeostasis, reduction of MMP, opening of MPTP, and release of mitochondrial cytochrome c observed in OGD/R-injured cells, which indicated a switch on the mitochondrial-mediated apoptotic pathway, were all reversed by resveratrol. These results suggest that resveratrol administration may play a neuroprotective role via modulating the mitochondrial-mediated signaling pathway in OGD/R-induced PC12 cell injury.