Neuroprotective actions of deferiprone in cultured cortical neurones and SHSY-5Y cells

Alzheimer's disease (AD) is a common neurodegenerative disorder, but the initiating molecular processes contributing to neuronal death are not well understood. AD is associated with elevated soluble and aggregated forms of amyloid beta (A beta) and with oxidative stress. Furthermore, there is increasing evidence for a detrimental role of iron in the pathogenic process. In this context, iron chelation by compounds such as 3-hydroxypyridin-4-one, deferiprone (Ferriprox (TM)) may have potential neuroprotective effects. We have evaluated the possible neuroprotective actions of deferiprone against a range of AD-relevant insults including ferric iron, H2O2 and A beta in primary mouse cortical neurones. We have investigated the possible neuroprotective actions of deferiprone (1, 3, 10, 30 or 100 mu M) in primary neuronal cultures following exposure to ferric iron [ferric nitrilotriacetate (FeNTA); 3 and 10 mu M], H2O2 (100 mu M) or A beta 1-40 (3, 10 and 20 mu M). Cultures were treated with deferiprone or vehicle either immediately or up to 6 h after the insult in a 24-well plate format. In order to elucidate a possible neuroprotective action of deferiprone against Parkinson's disease relevant insults another group of experiments were performed in the human neuroblastoma catecholaminergic SHSY-5Y cell line. SHSY-5Y cells were treated with MPP+ iodide, the active metabolite of the dopaminergic neurotoxin MPTP and the neuroprotective actions of deferiprone evaluated. Cytotoxicity was assessed at 24 h by lactate dehydrogenase release, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide turnover (FeNTA and hydrogen peroxide) and morphometric analysis of cell viability by Hoechst 33324/propidium iodide (FeNTA, A beta and MPP+) or 6-carboxyfluorescein diacetate and annexin V-Cy3 (A beta). The present study demonstrates that deferiprone protects against FeNTA, hydrogen peroxide, MPP+ and A beta 1-40-induced neuronal cell death in vitro, which is consistent with previous in vitro and in vivo studies that have demonstrated similar protection with other iron chelators.