Synthesis of Autotaxin-Inhibiting Lipid Nanoparticles to Regulate Autophagy and Inflammatory Responses in Activated Macrophages.

Background: Autotaxin (ATX), an ENPP2 enzyme, regulates lipid signaling by converting lysophosphatidylcholine to lysophosphatidic acid (LPA). Dysregulation of the ATX/LPA axis promotes inflammation and disease progression. BMP-22, a lipid ATX inhibitor, effectively reduces LPA production. However, its clinical utility is hampered by limitations in solubility and pharmacokinetics. To overcome these limitations, we developed BMP-22-incorporated lipid nanoparticles (LNP-BMP) to improve utility while maintaining ATX inhibition efficacy.

Methods: LNP-BMP was synthesized by incorporating DOTAP, DOPE, cholesterol, 18:0 PEG₂₀₀₀-PE, and together with BMP-22. The formulation of LNP-BMP was optimized and characterized by testing different molar ratios of BMP-22. The autophagy recovery and anti-inflammatory effects of LNP-BMP via ATX inhibition were evaluated in both macrophage cell line and mouse-derived primary macrophages.

Results: LNP-BMP was shown to retain its functionality as an ATX inhibitor and maintain the physical characteristics upon BMP-22 integration. Synthesized LNP-BMP exerted superior ability to inhibit ATX activity. When applied to M1-induced macrophages, LNP-BMP exhibited substantial anti-inflammatory effects and successfully restored autophagy activity.

Conclusion: The results demonstrate that LNP-BMP effectively inhibits ATX, achieving both anti-inflammatory effects and autophagy restoration, highlighting its potential as a standalone immunotherapeutic agent. Furthermore, the capacity to load therapeutic drugs into this formulation offers promising opportunities for further therapeutic strategies.