Neuroprotective effects of adipose-derived stem cells on ferrous sulfate-induced neurotoxicity

Background:Ferrous ion,a degradation product of hematomas,induces inflammatory reactions and other secondary injuries after intracerebral hemorrhage(ICH).Our study aimed to investigate the specific neuroprotective mechanism of adipose-derived stem cells(ADSCs)on ferrous ion-induced neural injury in vitro.Methods:ADSCs were co-cultured with primary cortical neurons in a transwell system treated with ferrous sulfate to generate an in vitro ICH model.ADSCs and cortical neurons were cultured in the upper and lower chambers,respectively.Neuron apoptosis was determined by flow cytometry.The levels of insulin-like growth factor-1(IGF-1),malondialdehyde(MDA)and nitric oxide synthase(NOS)activity in neuron culture medium were detected with commercial kits.In neurons,protein expression in phosphatidylinositol-3-kinase(PI3 K)/protein kinase B(Akt)signaling pathway,nuclear factor erythroid 2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathway and apoptosis-related proteins were detected by western blot.Results:ADSCs attenuated neural apoptosis,reduced MDA levels and NOS activity induced by ferrous sulfate.In neurons,IGF-1 was increased,as were p-PI3 K,p-Akt,Nrf2,HO-1,and Bcl-2 while cleaved caspase 3 was down-regulated.Conclusions:ADSCs exert neuroprotective effects against ferrous iron-induced neuronal damage by secreting IGF-1 and increasing the levels of Akt-dependent Nrf2/ARE signaling pathway.