Lactoferrin Suppresses LPS-Induced Expression of HMGB1, microRNA 155, 146, and TLR4/MyD88/NF-кB Pathway in RAW264.7 Cells

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 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 could modulate HMGB1, mmu-mir -155, mmu-mir -146a and TLR4/MyD88/NF-кB pathway.