Role of NOX/ROS in 5-HT-mediated proliferation of rat pulmonary artery smooth muscle cells

Abstract

Objective To observe whether serotonin (5-HT)-mediated proliferation of pulmonary artery smooth muscle cells (PASMCs) is related to the increase of intracellular reactive oxygen species (ROS), and identify the role of NADPH oxidase (NOX) in the production of ROS and 5-HT-mediated proliferation. Methods Tissue block culture method was used to establish a cell line of human PASMCs. Then the cells were divided into 6 groups, normal control (no treatment), 5-HT treatment (1 μmol/L 5-HT), and 3 intervention groups. Then NOX activity was analyzed by using spectrophotometer to calculate the amount of NADPH consumed. ROS production was measured by DCF-DA assay. The expression of phosphorylated-ERK1/2 (p-ERK1/2) was detected by Western blotting. The changes of PASMC proliferation were determined 3H-TdR incorporation assay. Results 5-HT stimulation for 30 min obviously enhanced the NOX activity, ROS production, DNA synthesis, and expression of p-ERK1/2 (all P < 0.05). While the pretreatment of DPI, Tempol or PD98059 could significantly reverse the ERK1/2 phosphorylation and DNA synthesis induced by 5-HT stimulation (both P < 0.05). What's more, DPI also notably reduced the generation of ROS (P < 0.05). Conclusion NOX/ROS may be the key proteins in the signaling pathways of 5-HT mediated proliferation of PASMCs.

Keywords

• 5-ht
• nadph oxidase
• reactive oxygen species
• erk1/2
• pulmonary artery smooth muscle cells