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Background Disrupted iron homeostasis in the substantia nigra (SN) is an important mechanism in Parkinson’s disease (PD). In our previous studies using cultured neurons, we showed that 6-hydroxydopamine (6-OHDA) treatment increased the expression of divalent metal transporter-1 (DMT1) gating iron influx and decreased the expression of ferroportin 1 (FPN1) gating iron efflux, leading to increased iron deposition. In astrocytes, 6-OHDA increased both DMT1 and FPN1 expressions and iron traffic. However, the underlying mechanisms mediating these processes remain elusive. Hypoxia-inducible factors (HIFs) are important regulators of iron homeostasis. Methods Using western blots, we observed HIFs, DMT1 and FPN1 expressions in primary cultured astrocytes and ventral mesencephalic (VM) treated with 6-OHDA, inhibitors of HIF-1α and HIF-2α, protein kinase C (PKC) inhibitor and PKC activator, radical scavenger and inducible NO synthase (iNOS) inhibitor. The ferrous iron traffic of astrocytes was determined by measuring the quenching or reversing of calcein fluorescence. Results Using primary rat cell cultures, we observed that 6-OHDA treatment significantly increased the expressions of HIF-1α and HIF-2α in cultured astrocytes but not in VM neurons. Moreover, we observed that HIF-2α inhibitor, but not HIF-1α inhibitor reversed the 6-OHDA-induced upregulation of DMT1 and FPN1 and ferrous iron traffic. Blocking protein kinase C (PKC) pathway by bisindolylmaleimide I hydrochloride (Bisl) or N-acetyl-l-cysteine (NAC) or Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) inhibits Phorbol 12-myristate 13-acetate (PMA) or 6-OHDA induced activation of HIF-2α, whereas activating by PMA or 6-OHDA was sufficient to activate HIF-2α. Notably, blocking of PKC delta (PKC δ) phosphorylation by NAC, or L-NAME inhibits 6-OHDA induced activation of HIF-2α. Conclusion Our data indicate that astrocytic HIF-2α, but not HIF-1α, may be an important regulator of DMT1 and FPN1 expressions by activating the PKC -dependent pathway.

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