Objective: To investigate the regulatory effect of microRNA-141 (miR-141) on expression of high mobility group protein B1(HMGB1) in human monocytes THP-1 cell line.
Methods: THP-1 cells were transfected with miR-141 mimic or inhibitor (100 nmol/L) for 48 hours with lipofectamine RNAi MAX. The levels of miR-141 and HMGB1 mRNA in the THP-1 cells were detected by real-time fluorescence quantitation reverse transcription-polymerase chain reaction (RT-PCR), and HMGB1 protein was determined with Western blotting.
Results: The levels of miR-141 could be up regulated (35.33±7.24 vs. 1.21±0.20, t=-8.408, P=0.010) or down regulated (0.55±0.12 vs 1.09±0.05, t=7.473, P=0.002) after being transfected with 100 nmol/L miR-141 mimic or inhibitor for 48 hours by lipofectamine RNAi MAX in THP-1, and the level of HMGB1 mRNA and protein decreased (mRNA: 0.43±0.06 vs. 0.97±0.08, t=9.760, P=0.001; protein: 0.63±0.12 vs. 1.00±0.11, t=2.991, P=0.040) or increased (mRNA: 2.13±0.11 vs. 1.16±0.13, t=-9.977, P=0.001; protein: 1.78±0.04 vs. 0.96±0.09, t=-13.778, P=0.000) simultaneously compared with the control group.
Conclusions: miR-141 is involved in regulation of inflammation through HMGB1 gene and protein pathway, suggesting that miR-141 plays an important role in regulating immune cells during the inflammatory response.