ABSTRACT
The aim of the present study was to investigate the effects of microRNA-338-3p (miR-338-3p) on morphine (MP)-induced apoptosis, and its underlying mechanisms. Freshlyisolated mouse peritoneal macrophages were cultured in vitro and treated with MP following transfection with miR3383p mimic, inhibitor or controls. miR3383p expression levels increased significantly following MP treatment (P<0.01). This increase was enhanced following transfection with miR3383p mimic (P<0.05) and abrogated following transfection with miR3383p inhibitor (P<0.05). The apoptotic rate increased significantly in groups treated with MP (P<0.05); however, this increase was abrogated by transfection with miR3383p inhibitor (P<0.05). Bioinformatics software predicted that sex determining region Ybox 4 (SOX4) was the target gene of miR3383p and this was verified using a dualluciferase reporter gene system. SOX4 mRNA and protein expression levels decreased significantly following MP treatment (P<0.05); however, this decrease was abrogated following transfection with miR3383p inhibitor (P<0.05). Caspase3 protein expression levels increased markedly following MP treatment (P<0.05); however, this increase was inhibited by transfection with miR3383p inhibitor (P<0.05). Therefore, decreased expression of miR3383p may suppress MPinduced apoptosis, potentially via the upregulation of SOX4 expression and the caspase3dependent apoptotic signaling pathway.