Enterovirus 71 structural viral protein 1 promotes autophagy by inducing an m6A-mediated PMP22 overexpression in mouse Schwann cells

Objective Enterovirus 71 (EV71), one of the enteroviruses responsible for the hand, foot and mouth disease (HFMD), can cause severe neurologic diseases such as brainstem encephalitis and demyelination. The molecular mechanism of demyelination is still not fully understood. This study aims to investigate the mechanism of how the EV71 structural viral protein 1, VP1 can act on host cellular pathways in mouse Schwann cells. Methods An EV71 VP1-expressing vector was generated and transfected into mouse Schwann cells (MSCs). Selective mRNA methylation inhibitor (DAA) was employed to identify key members of m6A pathway that are targeted by VP1. To investigate the role of METTL14 and YTHDF1 in PMP22 expression, small interfering RNA against METTL14 and YTHDF1 was employed to knockdown the METTL14 and YTHDF1 expression in MSCs. Real-time PCR and Western blot analysis were performed to determine the expression of PMP22 and m6A modification-associated proteins. Results Our results demonstrated VP1 upregulated m6A pathway by targeting METTL14 and YTHDF1. The expression of PMP22 was decreased by inhibiting the expression of METTL14 and YTHDF1. Conclusions VP1 upregulates m6A modification, which in turn causes the hypermethylation of PMP22 in MSCs, resulting in a higher level of PMP22. Ultimately, this VP1-induced PMP22 overexpression leads to MSC autophagy.