Objective To investigate the effects of ATP-binding cassette subfamily B transporter 6 subfamily B(ABCB6)on cognitive dysfunction in Alzheimer's disease(AD)rats and its possible potential regulatory molecular mechanisms.Methods Amyloid β-protein(Aβ)was injected to construct the AD mouse model in vivo.Water maze test and Y maze test were used to evaluate the learning and memory ability and space exploration ability of rats.An in vitro AD cell model was constructed by HT22 cells and Aβ.The binding relationship between YTH domain containing 1(YTHDC1)and ABCB6 was analyzed by RNA immuniprecipitation(RIP).Quantitative real time polymerase chain reaction(qRT-PCR)was used to detect overexpression and knockdown transfection efficiency.Western blot analysis was performed to detect the expression levels of YTHDC1 and ABCB6 proteins,as well as ferroptosis related proteins[Solute Carrier Family 7 Member 11(SLC7A11),Glutathione peroxidase 4(GPX4)].Cell viability was detected with CCK-8.Malondialdehyde(MDA),Glutathione(GSH),Reactive oxygen species(ROS)levels and Fe2+content were analyzed by the assay kit.Results The ABCB6 mRNA(3.51±0.17 vs 1.02±0.01,3.45±0.21 vs 1.02±0.01)and protein(3.25±0.14 vs 1.01±0.01,3.14±0.16 vs 1.01±0.01)levels in the hippocampus of AD mice and Aβ-induced HT22 cells were up-regulated,and the differences were statistically significant(t=-46.238,-20.349;-50.468,-23.013,all P<0.001).Knocking down ABCB6 decreased the time and distance of AD mice reaching the platform,and increased the ratio of spontaneous exchange rate to the number of times of entered the new arm(t=27.007,11.264,24.414,19.901,all P<0.001).Knockdown ABCB6 promoted HT22 cell proliferation,decreased levels of MDA and Fe2+,increased GSH levels,reduced ROS generation,and promoted expression of SLC7A11 and GPX4 proteins(t=2.883～26.122,all P<0.05).YTHDC1 protein promoted its stability by binding to ABCB6 mRNA and up-regulated the expression of ABCB6 protein.Knockdown of YTHDC1 decreased ABCB6 protein level(t=18.504,P<0.001),promoted the proliferation of HT22 cells,increased GSH content,SLC7A11 and GPX4 protein levels,decreased MDA and Fe2+content,and inhibited ROS production(t=4.404～14.486,all P<0.05).Knocking down YTHDC1 could improve the learning and memory ability and spatial exploration ability of AD mice.Over-expression of ABCB6 reversed the effects of YTHDC1 knockdown on ferroptosis in HT22 cells and cognitive dysfunction in AD mice.Conclusion YTHDC1 may induce ferroptosis of neuronal cells by mediating the up-regulation of ABCB6,thus promoting cognitive dysfunction in AD mice.