Lentivirus-mediated siRNA knockdown of METTL3 is involved in Alzheimer's disease

Abstract

Alzheimer's disease is the most common form of dementia in older people. The pathogenesis of AD is still uncertain, although it appears autophagy abnormalities are involved. In recent years, epigenetics, including RNA N6-methyladenosine (m6A) methylation, has been shown to be involved in the pathogenesis of neurodegeneration. However, how RNA methylation may be involved in the pathogenesis of AD is still unclear. Our previous RNA m6A methylation high-throughput sequencing analysis found that some hippocampal genes showed elevated methylation in AD mouse models, but that some genes showed declining methylation. Genes showing different methylation patterns tended to be related to autophagy. The focus of this study is to examine possible mechanisms by which m6A RNA methylation may be involved in AD. SH-SY5Y cells treated with Aβ25−35 were used as AD models, and untreated SH-SY5Y cells were used as controls. We first detected the expression of methylase in the two groups of cells. The results showed that the protein expression of METTL3 in the AD cell group was higher than that in the control group, while FTO expression showed no statistically significant differences. We then used lentivirus-mediated METTL3 RNA knockouts to observe the expression of Parkin protein in each group of cells. Results showed that expression of the Parkin protein in the AD cell group was increased compared to the control group, while the expression levels of Parkin protein in AD cells with METTL3 RNA knockout decreased. Additionally, mitochondrial structural changes were observed using transmission electron microscopy. These results showed that the mitochondrial structure in an AD cell model with METTL3 RNA knockout was improved compared to the AD cell model alone. Taken together, our findings suggest that RNA m6A methylation is involved in the AD process.