Global Proteomic Analysis Reveals Inflammatory Pathway Modulation Associated with miR-146a in LPS-Stimulated Macrophages

Inflammation is essential for host defense, but, when dysregulated, it contributes to tissue damage and chronic disease. MicroRNA-146a (miR-146a) is a well-recognized negative regulator of inflammatory signaling, primarily through suppression of the NF-κB pathway; however, its broader proteomic impact under inflammatory conditions remains incompletely defined. In this study, we overexpressed an miR-146a mimic in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and applied quantitative mass spectrometry to characterize global protein abundance changes. Functional overexpression was supported by reduced mRNA abundance of the established miR-146a targets TRAF6 and IRAK1 under LPS-stimulated conditions. Proteomic analysis identified 1232 proteins showing differential abundance under the predefined exploratory criteria, including proteins related to NF-κB activity, inflammasome components, nitric oxide synthesis, and IL-6-associated pathways. Proteins linked to interferon-related signaling were also altered. Targeted validation by quantitative RT-PCR and parallel reaction monitoring supported changes in selected inflammatory mediators, including PTGS2, NOS2, MAPKAPK2, and IRF3. Functionally, miR-146a overexpression was associated with reduced LPS-induced nitric oxide and IL-6 production. Together, these findings provide an exploratory proteomic overview of pathways associated with miR-146a overexpression in activated macrophages and suggest that miR-146a is associated with modulation of multiple inflammatory signaling networks under inflammatory conditions.