Abstract

BACKGROUND: PGC-1α can be activated by deacetylation reactions catalyzed by SIRT1. Resveratrol is currently known as a potent activator of SIRT1. However, it is unknown whether the renal-protective effect of resveratrol is further related to activation of the podocyte SIRT1/PGC-1α pathway.

MATERIAL AND METHODS: High glucose was used to stimulate mouse podocytes. Resveratrol and PGC-1α siRNA transfection were used to perform co-intervention treatments. The protein and mRNA expression levels of SIRT1, PGC-1α, NRF1, and TFAM were detect by immunofluorescence, Western blot analysis, and qRT-PCR in the podocytes, respectively. DCHF-DA and MitoSOX™ staining were used to monitor the total ROS and mitochondrial ROS levels, respectively. The specific activities of complexes I and III were measured using Complex I and III Assay Kits. Mitochondrial membrane potential and cell apoptosis were measured using JC-1 staining and Annexin V-FITC/PI double-staining, respectively.

RESULTS: We found that high-glucose stimulation results in time-dependent decreases in the expression of SIRT1, PGC-1α, and its downstream genes NRF1 and mitochondrial transcription factor A (TFAM) for mouse podocytes, and increases ROS levels in cells and mitochondria. Moreover, the expression of nephrin was downregulated and the cell apoptotic rate was increased. Resveratrol treatment can improve abnormalities caused by high-glucose stimulation. In addition, it can also reduce the release of mitochondrial cytochrome C and DIABLO proteins to the cytoplasm and increase respiratory chain complex I and III activity and mitochondrial membrane potential.

CONCLUSIONS: Resveratrol can reduce the oxidative damage and apoptosis of podocytes induced by high-glucose stimulation via SIRT1/PGC-1α-mediated mitochondrial protection.

Keywords: Genes, Mitochondrial, DNA-Binding Proteins, High Mobility Group Proteins, Membrane Potential, Mitochondrial, Mitochondria, Mitochondrial Proteins, Nuclear Respiratory Factor 1, peroxisome proliferator-activated receptor gamma coactivator 1-alpha, Podocytes, Protein Processing, Post-Translational, RNA, Small Interfering, resveratrol, Sirtuin 1, Transcription Factors