RESUMO
The purpose of the present study was to determine the effects of resveratrol on hypoxia-induced oxidative stress and proliferation in pulmonary artery smooth muscle cells (PASMCs) and the underlying mechanism. Primary rat PASMCs were isolated and cultured in vitro and pretreated with different concentrations of resveratrol (10, 20, and 40 µmol/L) or the NADPH oxidase (NOX) inhibitor VAS2870 (10 µmol/L) for 0.5 h. The cells were then cultured under normoxia (21% O2, 5% CO2) or hypoxia (2% O2, 5% CO2) for 24 h. The proliferation of cells was measured using the CCK-8 method and the expression of proliferating cell nuclear antigen (PCNA). The production of reactive oxygen species (ROS) was detected by DCFH-DA. The expression of rat NOX1, NOX4 and hypoxia inducible factor 1α (HIF-1α) was detected by real-time RT-PCR and Western blotting assays. The related signaling pathways were determined using the small interference RNAs (siRNAs) specifically targeting Hif-1α and Nox4. The results showed that resveratrol and VAS2870 significantly inhibited hypoxia-induced cell proliferation and ROS production in rat PASMCs. Resveratrol also effectively prevented hypoxia-induced increase of HIF-1α protein levels and NOX4 up-regulation, but had little effect on NOX1. After the knocking down of Hif-1α or Nox4 with siRNAs, hypoxia-induced cell proliferation and ROS accumulation were significantly decreased, and both were further inhibited by resveratrol treatment. These results suggest that resveratrol inhibits hypoxia-induced oxidative stress and cell proliferation in rat PASMCs possibly through blocking the HIF-1α/NOX4/ROS pathway.
