MicroRNA-138 Aggravates Inflammatory Responses of Macrophages by Targeting SIRT1 and Regulating the NF-κB and AKT Pathways

Cell Physiol Biochem. 2018;49(2):489-500. doi: 10.1159/000492988. Epub 2018 Aug 29.

Abstract

Background/aims: With increased understanding of sepsis, mortality is decreasing. However, there is still a lack of effective therapeutic strategy. The inflammatory response of macrophages is critical during sepsis.

Methods: Macrophages were stimulated with LPS. Western blotting and qRT-PCR were used to detect inflammatory responses. Then, the inhibitor of microRNA-138 was transfected and Western blotting, qRT-PCR, H&E staining and ELISA were used to verify the role of microRNA-138 in inflammation. Then target gene prediction databases were used to predict the potential target of microRNA-138. Both animal and cell models under LPS challenges were established to verify the regulation of SIRT1 and microRNA-138 during inflammation.

Results: The present study showed that microRNA-138 was increased in macrophages stimulated with LPS. Additionally, the NF-κB and AKT pathways were both activated. The pre-treatment of microRNA-138 inhibitor decreased inflammatory factors, downregulated the NF-κB pathway, activated the AKT pathway and protected against organ damage in mice challenged with LPS. SIRT1 was demonstrated as a potential target of microRNA-138In macrophages stimulated with LPS, the inhibition effect of microRNA-138 inhibitor on inflammation was lost by SIRT1 siRNA pre-treatment. In the animal model, the protective effect of microRNA-138 antagomir disappeared in SIRT1 knockout mice.

Conclusion: We demonstrated that miR-138 participated in the inflammatory process by inhibiting SIRT1 and activating the NF-κB pathway.

Keywords: AKT; Inflammation; Macrophage; MicroRNA-138; NF-κB; SIRT1.

MeSH terms

  • 3' Untranslated Regions
  • Animals
  • Antagomirs / metabolism
  • Interleukin-1beta / blood
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Interleukin-6 / blood
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism
  • Lipopolysaccharides / pharmacology
  • Macrophages / cytology
  • Macrophages / drug effects
  • Macrophages / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • MicroRNAs / antagonists & inhibitors
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • NF-kappa B / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • RAW 264.7 Cells
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • Signal Transduction / drug effects
  • Sirtuin 1 / antagonists & inhibitors
  • Sirtuin 1 / genetics
  • Sirtuin 1 / metabolism*
  • Tumor Necrosis Factor-alpha / blood
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • 3' Untranslated Regions
  • Antagomirs
  • Interleukin-1beta
  • Interleukin-6
  • Lipopolysaccharides
  • MIRN138 microRNA, mouse
  • MicroRNAs
  • NF-kappa B
  • RNA, Small Interfering
  • Tumor Necrosis Factor-alpha
  • Proto-Oncogene Proteins c-akt
  • Sirtuin 1