PI3K/Akt and ERK1/2 Signalling Are Involved in Quercetin-Mediated Neuroprotection against Copper-Induced Injury

Figure 5

Signalling by apoptotic and oxidative stress-related pathways. The effects of copper and quercetin on the expression of p53, Bax, PUMAα/β, and NME1/NME2 in moderate oxidative stress were monitored for 24 h from the beginning of treatment with 0.5 mM CuSO₄ and 150 μM quercetin, and proteins of total cell extracts were separated on 10 or 11% SDS polyacrylamide gel electrophoresis and transferred to a nitrocellulose membrane. Blots were probed with primary antibodies, followed by the appropriate horseradish peroxidase-labelled secondary antibody. Immunoreactivity was detected using enhanced chemiluminescence. β-Actin was used as loading control for normalization. Data are expressed as from up to five immunoblots of three independently prepared cell lysates. Exposure to copper and quercetin did not affect p53 and Bax expression. However, quercetin diminished copper-induced upregulation of PUMA and stimulated NME1 expression. Following densitometric analysis, obtained data were analyzed with one-way ANOVA followed by Dunnett’s test (^a, ^c). Representative Western blots are also presented.