Hu F, Sun WW, Zhao XT, Cui ZJ, Yang WX. TRPV1 mediates cell death in rat synovial fibroblasts through calcium entry-dependent ROS production and mitochondrial depolarization.
Biochem Biophys Res Commun 2008;
369:989-93. [PMID:
18331834 DOI:
10.1016/j.bbrc.2008.02.155]
[Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Accepted: 02/20/2008] [Indexed: 02/07/2023]
Abstract
Synoviocyte hyperplasia is critical for rheumatoid arthritis, therefore, potentially an important target for therapeutics. It was found in this work that a TRPV1 agonist capsaicin, and acidic solution (pH 5.5) induced increases in cytosolic calcium concentration ([Ca(2+)](c)) and reactive oxygen species (ROS) production in synoviocytes isolated from a rat model of collagen-induced arthritis. The increases in both [Ca(2+)](c) and ROS production were completely abolished in calcium-free buffer or by a TRPV1 antagonist capsazepine. Further experiments revealed that capsaicin and pH 5.5 solution caused mitochondrial membrane depolarization and reduction in cell viability; such effects were inhibited by capsazepine, or the NAD(P)H oxidase inhibitor diphenylene iodonium. Both capsaicin and pH 5.5 buffer induced apoptosis as shown by nuclear condensation and fragmentation. Furthermore, RT-PCR readily detected TRPV1 mRNA expression in the isolated synoviocytes. Taken together, these data indicated that TRPV1 activation triggered synoviocyte death by [Ca(2+)](c) elevation, ROS production, and mitochondrial membrane depolarization.
Collapse