Macrophages regulate plaque progression in diabetic Apoe-/- mice dependent on Pi4p/Nlrp3 signaling pathway

Abstract

Background and aims: Atherosclerotic cardiovascular disease complicated by diabetes mellitus (DM) is the leading cause of death in diabetic patients, and it is strongly associated with macrophages and inflammasomes. It has been found that activation of NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome is closely associated with phosphatidylinositol 4-phosphate (PI4P) on the trans-Golgi. However, how PI4P and NLRP3 regulate macrophage function and its role in diabetic atherosclerotic plaques is unclear.

Methods: The expression of Pi4p and Nlrp3-inflammasome-related proteins in atherosclerosis in apolipoprotein E-deficient (Apoe^-/-) and Apoe^-/- DM mice was investigated. Then, Pi4p levels were affected by shRNA-Pi4kb or cDNA-Sac1 plasmid to investigate the effects of changes in Pi4p-related metabolic enzymes on macrophage function. Finally, genetically modified macrophages were injected into diabetic Apoe^-/- mice to explore the effects on atherosclerosis.

Results: DM promoted plaque progression in atherosclerotic mice and increased expression of Pi4p and Nlrp3 in plaques. In addition, impaired macrophage function induced by high glucose was reversed by transfected shRNA-Pi4kb or cDNA-Sac1 plasmid. Furthermore, decreased levels of Pi4p reduced plaque area in diabetic Apoe^-/- mice.

Conclusions: Our data suggests that Pi4p/Nlrp3 in macrophages play an important role in the exacerbation of atherosclerosis in diabetic mice. Pi4p-related metabolizing enzymes (PI4KB and SAC1) may be a potential therapeutic strategy for diabetic atherosclerosis, and macrophage therapy is also a potential treatment.

Keywords: Adoptive transfer; Atherosclerosis; Diabetes mellitus; Macrophage; Nlrp3; Pi4p.