Exploring the mechanism of Jiawei Simiao Powder on monosodium urate crystal-induced RAW264.7 cell inflammation via miR-146a regulation of the TLR4/NF-κB signaling pathway

Objective: To investigate the mechanism by which Jiawei Simiao San regulates the Toll like receptor 4 (TLR4)/nuclear transcription factor - κ B (NF - κ B) signaling pathway through microRNA-146a (miR-146a) and alleviates the inflammatory response induced by MSU crystals in RAW264.7 cells. Method: RAW264.7 cells were induced with MSU crystals to establish a gouty arthritis model, which was divided into a control group, a model group, a modified Simiao powder group, and a colchicine group. The CCK-8 method was used to detect the activity of each group of cells, ELISA was used to detect the levels of interleukin-1 (IL), IL-6, and tumor necrosis factor (TNF) - α, RT-PCR was used to detect the mRNA expression of miR-146a and TLR4, myeloid differentiation factor 88 (MyD88), TNF receptor associated factor 6 (TRAF6), and NF - κ B p65, and Western blot was used to detect the protein expression of TLR4, MyD88, TRAF6, and p-NF - κ B p65. The correlation between miR-146a and TLR4, MyD88, TRAF6, NF - κ B p65, and p-NF - κ B p65 was analyzed. As a result, compared with the control group, the expression of miR-16a in the model group cells was significantly reduced (P<0.05), while the mRNA and protein expression of TLR4, MyD88, TRAF6, p-NF - κ B p65 protein expression, and the expression levels of IL-1, IL-6, and TNF - α were significantly increased (P<0.05); Compared with the model group, the expression of miR-16a in the Jiawei Simiao San group and the colchicine group was significantly increased (P<0.05), while the mRNA and protein expression of TLR4, MyD88, TRAF6, and p-NF - κ B were significantly decreased (P<0.05), and the contents of IL-1, IL-6, and TNF - α were significantly decreased (P<0.05). The correlation analysis results indicate that miR-146a is negatively correlated with TLR4, MyD88, TRAF6 mRNA and protein expression, as well as p-NF - κ B p65 protein expression (P<0.05). Conclusion: Jiawei Simiao San can alleviate MSU induced gout inflammation by upregulating miR-146a, inhibiting the activation of TLR4/NF - κ B signaling pathway, and reducing the expression of inflammatory factors.