Role Of Lovastatin In Attenuating The Decreased Muscarinic Acetylcholine Receptors And The Increased Oxidative Stress In Cultured Neurons Induced By ?-amyloid Peptide

Objective: The etiology and pathogenesis of Alzheimer's disease?AD?is still not fully understood,which obviously limits therapeutic investigation to the disease in clinic.Since the neurotoxicity of ?-Amyloid peptide?A??is a key factor in the pathogenesis of AD,we used lovastatin,one of statins as a traditional cholesterol-lowering drug,to study its effect on anti-A? neurotoxicity,specially concerning the changes of muscarinic acetylcholine receptors?mAChRs?and oxidative stress in order to reveal the neuroprotective mechanism of the drug with cholesterol independence in the treatment of AD.Methods: In the study,the primary cultured rat hippocampal neurons and SH-SY5 Y cells were employed.Immunofluorescence stain was used to identify the purity of primary neurons.After the primary neurons or SH-SY5 Y cells were exposed to lovastatin and A b Os,separately or combination for 24-48 hrs,the cell viability was detected by using CCK-8 assay;the protein and mRNA expressions of M1 and M3 mAChRs were measured by western blotting and real-time PCR,respectively;the contents of cholesterol and malondialdehyde?MDA?,the activities of superoxide dismutase?SOD?and glutathione peroxidase?GSH-Px?,and the levels of OH-,H₂O₂,O2·-by biochemical methods.Results: 1.The purity of primary neurons was above 85%;the cell viability and cholestetol level were not significantly changed in the cells treated with 0.01 or 0.1 ?mol/L lovastatin for 24 hrs.2.For the effect of lovastatin on the expression of mAChRs,the protein and mRNA of M1 and M3 mAChRs were significantly increased in the cells treated with 0.01 or 0.1 ?mol/L lovastatin for 24 hrs.3.For the effect of lovastatin against the A b Os on mAChRs,the protein and mRNA of M1 and M3 mAChRs were obviously decreased in the cells after being treated with 0.5 ?mol/L A b Os,while the decreased M1 and M3 mAChRs were alleviated when the cells were pretreated with 0.1 ?mol/L lovastatin for 24 hr before AbOs.4.For the neuroprotective effect of lovastatin against the AbOs,the activities of SOD and GSH-Px were significantly decreased,while MDA content and the levels of OH-,H₂O₂,O2·-obviously increased in the cells treated with 0.5 ?mol/L AbOs for48 hrs,while these neurotoxic modifications resulted from A b Os were all significantly attenuated when the cells were pretreated with 0.1 ?mol/L lovastatin for24 hrs before AbOs.Conclusion: 1.The treatment with 0.01 or 0.1 mmol/L lovastatin didn't significantly influence the cell viability and the level of cholesterol.2.Lovastatin may up-regulate mAChRs to against the toxicity of Ab.3.Lovastatin can attenuate the neurotoxic effects induced by AbOs concerning the increased content of MDA,the decreased activities of SOD and GSH-Px,and the raised levels of OH-,H₂O₂,O2·-.In summary,lovastatin may play a role to against the toxicity of A? that induces the decreased expression of mAChRs and the increased level of oxidative stress,which may provide an important evidence for the therapy of AD by statins with cholesterol independence.