P90RSK and Nrf2 Activation via MEK1/2-ERK1/2 Pathways Mediated by Notoginsenoside R2 to Prevent 6-Hydroxydopamine-Induced Apoptotic Death in SH-SY5Y Cells
Figure 7
Neuroprotection of NGR2 involved the activation of P90RSK and Nrf2 through MEK1/2-ERK1/2 pathway. Protein expression was determined by western blot analysis. Both MEK1/2 siRNA (a) and ERK1/2 siRNA (b) suppressed NGR2-mediated activation of P90RSK and Nrf2. (c) NGR2-mediated activity enhancement of HO-1, GSH-PX, and GR was abolished by transfection of SH-SY5Y cells with MEK1/2 siRNA, ERK1/2 siRNA, and Nrf2 siRNA and by MEK inhibitor PD98059. The results are expressed as the mean ± SD of three independent experiments. ## indicates a significant difference from the control (). ** indicates a significant difference from the NGR2 treatment alone (). (d) The protective effect of NGR2 against 6-OHDA was partly abolished by Nrf2 siRNA and completely abolished by MEK1/2 siRNA, ERK1/2 siRNA, and PD98059. The results are expressed as the mean ± SD of three independent experiments. ## indicates a significant difference from the control (). ** indicates a significant difference from the 6-OHDA treatment alone (). & indicates a significant difference from NGR2+6-OHDA group (). && indicates a significant difference from NGR2+6-OHDA group ().
