A novel teleost microRNA regulates autophagy and NF-κB activation during bacterial infection

Fish Shellfish Immunol. 2023 Jun:137:108778. doi: 10.1016/j.fsi.2023.108778. Epub 2023 Apr 30.

Abstract

MicroRNAs (miRNAs) are a class of non-coding RNAs with regulatory functions in many cellular processes, including immune defense. In this study, we identified novel-m0089-3p, a novel miRNA with unknown function, in the teleost fish Japanese flounder (Paralichthys olivaceus) and investigated its immune function. Novel-m0089-3p was found to target the autophagy-associated gene ATG7 and negatively regulate ATG7 expression via interaction with the 3' UTR of ATG7. During the infection of the bacterial pathogen Edwardsiella tarda, novel-m0089-3p expression was induced in flounder, which in turn repressed ATG7 expression. Overexpression of novel-m0089-3p or blocking ATG7 expression inhibited autophagy and promoted the intracellular replication of E. tarda. Novel-m0089-3p overexpression, as well as E. tarda infection, activated NF-κB and stimulated the expression of inflammatory cytokines. Together these results revealed an important role of novel-m0089-3p in response to bacterial infection.

Keywords: Autophagy; Bacterial infection; Immune regulation; MicroRNA; Paralichthys olivaceus.

MeSH terms

  • Animals
  • Autophagy
  • Edwardsiella tarda / physiology
  • Enterobacteriaceae Infections*
  • Fish Diseases*
  • Fish Proteins
  • Flounder*
  • Gene Expression Regulation
  • MicroRNAs* / metabolism
  • NF-kappa B / genetics
  • NF-kappa B / metabolism

Substances

  • MicroRNAs
  • NF-kappa B
  • Fish Proteins