Fig. 4

NRG1 reduced the increase in ROS and decreased oxidative stress-related enzyme activity induced by CoCl₂. a After 24 h, intracellular ROS levels were measured by fluorescence microscopy using DCFH-DA dye that was administered to 100 µM CoCl₂-treated SH-SY5Y cells that had been pretreated with NRG1 (5 or 10 nM) for 15 min. b Bar graph summarizing the data in a (n = 6; ***P < 0.001 versus the control group; ^#P < 0.05, ^##P < 0.01 versus the CoCl₂ alone group). c SH-SY5Y cells were treated with 100 µM CoCl₂ alone or with PBS or NRG1 (5 nM or 10 nM) for 36 h. GPx activity was measured using a GPx assay kit (Cayman Chemical Company, MI, USA) (n = 6; **P < 0.01 versus the control group; ^###P < 0.001 versus the CoCl₂ alone group). d After the SH-SY5Y cells were exposed to 100 µM CoCl₂ in the presence or absence of NRG1 (5 nM or 10 nM) for 36 h, SOD activity was evaluated by measuring the inhibition of the reduction of tetrazolium salt by xanthine-xanthine oxidase according to the manufacturer’s instructions (Cayman Chemical Company, MI, USA). The SOD assay measured all three types of SOD (FeSOD, Cu/An, and Mn) (n = 8; ***P < 0.001 versus the control group; ^#P < 0.05, ^##P < 0.01 versus the CoCl₂ alone group)