Neuroprotective Effect of Crocin on Neuron Damage Induced by Aβ 25-35 by Mediating DKK3
Objective:To study the neuroprotective effect of Crocin mediated Dickkopf3(DKK3)on neuron damage induced by Aβ25-35 and its mechanism.Methods:Mouse hippocampal neuron HT-22 cells were in-duced by Aβ25-35,then CCK-8 test was used to determine optimal intervention concentration of Crocin.q-PCR was used to detect the DKK3 mRNA expression of DKK3 silencing plasmid(DKK3 siRNA)and DKK3 overexpression plasmid(DKK3-OE),then plasmids were transfected into cells.Cells we divided into normal group,Aβ25-35 group,Aβ25-35 + Crocin group(1.0 μmol/L),Aβ25-35 + DKK3 siRNA group,Aβ25-35 +siRNA control group,DKK3-OE group,plasmid control group,DKK3-OE + Crocin group(1.0 μmol/L).Flow cytometry assay was used to detect cell apoptosis,staining to observe cell synaptic morphology,Wes-tern blot was used to detect protein expressions of Aβ,DKK3,β-catenin,GSK-3β,p-GSK-3β,Caspase-3,Bax,Bcl-2.Results:0.5~2.0 μmol/L Crocin significantly could increase cell activity(P<0.01).Compared to normal group,apoptosis in Aβ25-35 group and DKK3-OE group were significantly increased,synaptic length and number of branches were significantly reduced,and protein expressions of Aβ,DKK3,p-GSK-3 β/GSK-3 β,Caspase-3 and Bax were significantly increased,the protein expressions of β-catenin and Bcl-2 were significantly decreased(P<0.01).Compared to DKK3-OE group,Crocin could reverse the above results.Compared to Aβ25-35 group,Aβ25-35 + Crocin group and Aβ25-35 + DKK3 siRNA group cell apoptosis were significantly decreased,synaptic length and number of branches were significantly increased,pro-tein expressions of Aβ,DKK3,p-GSK-3 β/GSK-3β,Caspase-3 and Bax were significantly decreased,while the protein expressions of β-catenin and Bcl-2 were significantly increased(P<0.05).Conclusion:Crocin has a protective effect on injury of nerve cell in-duced by Aβ25-35,it related to regulate expression of GSK-3 β/β-catenin signaling pathway by mediating DKK3.