Expression of superoxide dismutase 3 (SOD3) during orthodontic tooth movement in rats

Abstract

Hypoxia induces reactive oxygen species (ROS) production in periodontal tissues. Superoxide dismutase 3 (SOD3) is an enzyme protecting cells from ROS. This study investigated SOD3 expression and function during rat orthodontic tooth movement (OTM) and in hypoxia-exposed rat PDL cells. OTM of right maxillary first molars were performed in Sprague-Dawley rats for 1 and 14 days (n = 6 per group). SOD3 and HIF-1α expression were evaluated by immunohistochemistry. SOD3 effects on cell viability and proliferation, ROS production, and mRNA expression of Hif-1α, Rankl, and Opg in PDL cells and osteoclast differentiation were investigated under normoxia and hypoxia. SOD3 expression in PDL tissues decreased on compression side on day 1 and on both sides on day 14. HIF-1α levels significantly increased on compression side on day 14. Cell viability, cell proliferation, and Opg mRNA expression decreased, whereas ROS production and Hif-1α and Rankl mRNA expression increased in SOD3-silenced PDL cells. Hypoxia reduced Sod3 and Opg mRNA expression and increased ROS, Rankl mRNA expression, and osteoclast formation; SOD3 treatment attenuated these effects. Therefore, SOD3 plays a role in periodontal remodelling during OTM and in hypoxia-exposed PDL cells through ROS, HIF-1α, and RANKL/OPG pathways.