Lactoferrin suppresses LPS-induced expression of HMGB1, microRNA 155, 146, and TLR4/MyD88/NF-кB pathway in RAW264.7 cells

Immunopharmacol Immunotoxicol. 2021 Apr;43(2):153-159. doi: 10.1080/08923973.2021.1872616. Epub 2021 Jan 12.

Abstract

Objective: This current study evaluated the underlying mechanisms of LF against the inflammatory microRNAs (miRNAs), HMGB1 expression, and TLR4-MyD88-NF-кB pathway in LPS-activated murine RAW264.7 cells.

Methods: MTT assay was used to assess cell metabolism and the cell culture levels of the cytokines (TNF-α, IL-6) were evaluated by Enzyme-linked immunosorbent assay (ELISA). The expression of miRNAs was quantified by using qPCR and the expression of HMGB1, TLR4, MyD88, and phosphorylated NF-κB (P-p65) were determined with Western blot and qPCR, respectively.

Results: The results indicated that LF downregulates IL-6 and TNF-α expression. LF exhibited the degradation of P-p65 and reduced the production of HMGB1, TLR4, and MyD88 in LPS-induced inflammatory response. Importantly, in parallel with the suppression of cytokines and HMGB1-TLR4-MyD88-NF-кB pathway, LF could induce a decrease in inflammatory selected miRNAs, mmu-mir-155, and mmu-mir-146a expression.

Conclusions: Altogether, these findings provide LF as a prominent anti-inflammatory agent that could modulate HMGB1, mmu-mir-155, mmu-mir-146a, and TLR4/MyD88/NF-кB pathway.

Keywords: HMGB1; Lactoferrin; MicroRNA; RAW264.7; TLR4-MyD88-NF-кB.

MeSH terms

  • Animals
  • Dose-Response Relationship, Drug
  • Gene Expression
  • HMGB1 Protein / antagonists & inhibitors*
  • HMGB1 Protein / biosynthesis
  • Lactoferrin / pharmacology*
  • Lipopolysaccharides / toxicity
  • Mice
  • MicroRNAs / antagonists & inhibitors*
  • MicroRNAs / biosynthesis
  • Myeloid Differentiation Factor 88 / antagonists & inhibitors*
  • Myeloid Differentiation Factor 88 / biosynthesis
  • NF-kappa B / antagonists & inhibitors*
  • NF-kappa B / biosynthesis
  • RAW 264.7 Cells
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Toll-Like Receptor 4 / antagonists & inhibitors*
  • Toll-Like Receptor 4 / biosynthesis

Substances

  • HMGB1 Protein
  • HMGB1 protein, mouse
  • Lipopolysaccharides
  • MicroRNAs
  • Mirn146 microRNA, mouse
  • Mirn155 microRNA, mouse
  • Myd88 protein, mouse
  • Myeloid Differentiation Factor 88
  • NF-kappa B
  • Tlr4 protein, mouse
  • Toll-Like Receptor 4
  • Lactoferrin