Effects of exercise preconditioning combined with electroacupuncture on learning memory capacity and hippocampal neuronal ferroptosis in rats with vascular dementia
Effects of exercise preconditioning combined with electroacupuncture on learning memory capacity and hippocampal neuronal ferroptosis in rats with vascular dementia
AIM:To investigate the effects of exercise preconditioning(EP)combined with electroacupunc-ture(EA)on learning and memory ability of rats with vascular dementia(VD),and to explore role of hippocampal ferrop-tosis in this process.METHODS:Seventy-two male SD rats were randomly divided into non-EP group and EP group,with 36 rats in each group.The rats were subjected to EP,and subsequently to establish the VD model.The rats from non-EP group were randomly divided into sham group,model group(VD group)and VD-EA group,each with 12 rats,while those in EP group were randomly divided into EP-sham group,EP-VD group and EP-VD-EA group,each with 12 rats.All rats in EP group underwent 4 weeks of swimming exercise training,5 d per week,30 min per day.At the end of the 4th week,the rats in VD,EP-VD,EP-VD-EA and VD-EA groups were used to induce the VD model,and the rats in sham and EP-sham groups received a sham surgery to simulate the VD model.On the 7th day after successful modeling,the rats in EP-VD-EA and VD-EA groups were treated with EA for 4 weeks,6 d per week,30 min per day.At the end of the inter-vention,the learning and memory ability of the rats was evaluated using Morris water maze.Neuron morphology in the CA1 area of rat hippocampus was observed through Nissl staining.Ferrous ion(Fe2+),malondialdehyde(MDA)and re-duced glutathione(GSH)contents in the rat hippocampal tissues were quantified using the colorimetric assay.The expres-sion levels of ferroptosis-related proteins,nuclear factor E2-related factor 2(Nrf2)and glutathione peroxidase 4(GPX4),in the hippocampal tissues were quantified by Western blot method.RESULTS:Compared with sham group,the rats in VD group exhibited longer mean evasion latency and decreased number of traversals across the plateau(P<0.01).The neurons in the CA1 region of the hippocampus were loose and disorganized,exhibiting an irregular cellular morphology.The hippocampal Fe2+and MDA content was elevated,and the GSH content was reduced(P<0.01).The protein levels of hippocampal Nrf2 and GPX4 were decreased(P<0.01).Compared with VD group,the rats in EP-VD,EP-VD-EA and VD-EA groups showed a shorter average escape latency and an increased number of traversals across the plateau(P<0.05).Neurons in the hippocampal CA1 area were more neatly arranged,showing regular cellular morphology.The hip-pocampal Fe2+and MDA contents of the rats in EP-VD group were significantly reduced(P<0.01),while the GSH content was elevated(P<0.05).Hippocampal Fe2+and MDA contents were significantly reduced and GSH contents were signifi-cantly increased in EP-EA and EA groups(P<0.01).The protein levels of hippocampal Nrf2 and GPX4 in EP-VD,EP-VD-EA and VD-EA groups were significantly increased(P<0.01).CONCLUSION:Exercise preconditioning combined with EA improves learning and memory ability in VD rats by reducing hippocampal intra-neuronal iron overload,maintain-ing organismal redox homeostasis,and inhibiting ferroptosis.
关键词
运动预处理/电针/血管性痴呆/铁死亡/学习记忆能力
Key words
exercise preconditioning/electroacupuncture/vascular dementia/ferroptosis/learning and memory ability