MicroRNA-302 Cluster Downregulates Enterovirus 71-Induced Innate Immune Response by Targeting KPNA2

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• Enterovirus 71 (EV71) causes severe inflammation via elevated cytokines and chemokines.
• MicroRNA (miR) 302 cluster's role in EV71-induced inflammation is largely unknown.
• Previous work linked miR-302c to influenza A virus IFN regulation.

Purpose of the Study:

• To investigate the miR-302 cluster's role in EV71-induced proinflammatory responses.
• To identify targets of the miR-302 cluster in the context of EV71 infection.
• To elucidate the molecular mechanisms linking miR-302 cluster, KPNA2, and EV71 pathogenesis.

Main Methods:

• Analysis of cytokine and chemokine levels in EV71 infection.
• Investigating miR-302 cluster regulation of gene expression.
• Identifying direct targets of the miR-302 cluster using molecular assays.
• Assessing KPNA2's interaction with signaling pathways (JNK1/JNK2, p38).
• Comparing miR-302 cluster and KPNA2 expression in EV71-infected patients versus controls.

Main Results:

• The miR-302 cluster was found to control EV71-induced cytokine expression.
• Karyopherin α2 (KPNA2) was identified as a direct target of the miR-302 cluster.
• EV71 infection upregulates KPNA2 by downregulating the miR-302 cluster.
• KPNA2 promotes JNK1/JNK2 and p38 translocation to the nucleus.
• EV71 patients showed decreased miR-302 cluster and increased KPNA2 expression, with a significant correlation.

Conclusions:

• The miR-302/KPNA2 axis is critically involved in EV71-induced cytokine expression.
• This axis represents a novel mechanism in EV71 pathogenesis.
• The miR-302/KPNA2 pathway presents a promising therapeutic target for EV71 infections.