fig7

Figure 7. Melatonin inhibition of iron-induced Tau hyperphosphorylation in HT22 cells involves hepcidin secreted by D1A cells. (A-E) HT22 cells were untreated or treated with 50 μM melatonin, 100 μM FAC, 50 μM melatonin + 100 μM FAC for 24 h. Cell lysates were then collected from these cells and subjected to western blotting analysis to evaluate Tau hyperphosphorylation at Ser202, Ser396, Ser404, and Thr181 using their antibodies; (F-H) The expression levels of hepcidin and FPN were tested by immunoblotting in HT22 cells; (I-K) The expression levels of hepcidin and FPN were shown in D1A cells after melatonin and/or FAC treatment; (L-N) The HT22 cells, which were treated respectively with melatonin- and/or FAC-treated D1A cells media, were subjected to western blotting analysis using hepcidin, FPN, GPX4, p-Tau (Ser202), p-Tau (Ser396), p-Tau (Thr181), and T-Tau antibodies. β-actin was used as an internal control. Values are represented as the means ± SEM (n = 3). ^*P < 0.05 compared with the Control group; ^#P < 0.05 compared with the FAC group. FAC: Ferric ammonium citrate; FPN: ferroportin; GPX4: glutathione peroxidase 4; SEM: standard error of the mean.