MiR-26a inhibits the inflammatory response of microglia by targeting HMGA2 in intracerebral hemorrhage

J Int Med Res. 2020 Jun;48(6):300060520929615. doi: 10.1177/0300060520929615.

Abstract

Objective: Intracerebral hemorrhage (ICH) is a common cerebrovascular disease with high mortality and poor prognosis. Therefore, the biological function and underlying molecular mechanism of miR-26a in inflammatory injury following ICH was investigated.

Methods: The potential role of miR-26a was investigated in lipopolysaccharide (LPS)-treated microglial cells by quantitative real-time PCR. To explore the potential role of HMGA2 in the miR-26a-regulated inflammatory response, LPS-induced microglial cells were cotransfected with an miR-26a mimic and pcDNA-HMGA2. Then, lentivirus-mediated overexpression of an miR-26a mimic in mouse microglial cells was performed, and the effects of miR-26a treatment on IL-6, IL-1β, and TNF-α expression in the mouse brain, neurological behavior, and rotarod test performance of mice after ICH were observed.

Results: MiR-26a was significantly downregulated in LPS-treated microglia and ICH mouse models. MiR-26a markedly reduced IL-6, IL-1β, and TNF-α expression in LPS-treated microglial cells. Furthermore, HMGA2 was verified as a direct target of miR-26a. In vivo, miR-26a overexpression in mouse microglial cells significantly suppressed proinflammatory cytokine expression in mouse brains and markedly improved the neurological behavior and rotarod test performance of mice after ICH.

Conclusion: MiR-26a remarkably inhibited proinflammatory cytokine release by targeting HMGA2, indicating that miR-26a could protect against secondary brain injury following ICH.

Keywords: HMGA2; Intracerebral hemorrhage; cytokine release; inflammatory response; miR-26a; microglia.

MeSH terms

  • Animals
  • Cerebral Hemorrhage / drug therapy
  • Cerebral Hemorrhage / genetics
  • Cytokines / genetics
  • Lipopolysaccharides
  • Mice
  • MicroRNAs* / genetics
  • Microglia*

Substances

  • Cytokines
  • Lipopolysaccharides
  • MicroRNAs
  • Mirn26 microRNA, mouse