Figure 9. Illustration depicting the modulation of the production of NALP3 inflammasome-mediated IL-1β in human monocytes by dietary fatty acids.
The major dietary saturated fatty acid palmitic acid (C16:0) induces, but the n-3 fatty acid docosahexaenoic acid (DHA) inhibits, heterodimerization of TLR2 with TLR1. The heterodimerization leads to the activation of downstream intracellular signaling pathways that culminates in the expression of pro-IL-1β which is cleaved by constitutively activated caspase-1 to secrete mature IL-1β. Therefore, the primary signals to induce the expression of pro-IL-1β are sufficient for the production of mature IL-1β in human monocytes. Palmitic acid also upregulates the expression of NALP3 which could potentiate NALP3 inflammasome activity.
