Methylcobalamin Protected PC12 Cells From Aβ_25-35Induced Cytotoxicity

Objective:Alzheimer ’s diseases(AD)is the most common aging-associated dementia.It is estimated that the number of AD patient will be increased exponentially due to the rapidly growing aging population.Currently,there is no cure for AD.Methylcobalamin is a form of vitamin B12 and it has been used to treat neurological diseases.Some clinical trials also show that methylcobalamin slow the cognitive decline in elder people.The purpose of this study is to test whether methylcobalamin can reduce the cytotoxicity of Aβ.Methods:The AD cell model is established by using PC12 cells treated with Aβ25-35 for 24 h.In this study,we investigated the protective effects of methylcobalamin on Aβ25-35 induced cytotoxicity.Results:Compare to AD model cells treated with vehicle,methylcobalamin increased the cell viability and mitochondrial potential,decreased reactive oxygen species(ROS)level,mitochondrial calcium concentration,and the number of apoptotic cells.These results were detected by cell counting kit-8(CCK-8),JC-1,DCFH-DA(2,7-dichlorodihydrofluorescein diacetate)probe,Rhod2 calcium indicator and Annex-V/PI assay.The relative quantities of mRNA and protein were determined by RT-PCR and Western blot,respectively.Methylcobalamin upregulated the mRNA expression of mfn2,gsr,akt and the protein expression of p-Akt and PGC1-α.Moreover,methylcobalamin downregulated the expression of Caspase-3 protein and decreased the value of bax/bcl2.Conclusions:These results demonstrated that methylcobalamin could reduce the cytotoxicity induced by Aβ25-35,partly by inhibiting cell apoptosis.Our data suggest that methylcobalamin may be a good neuroprotective candidate to treat AD.