7-Difluoromethoxy-5,4′-dimethoxy-genistein attenuates macrophages apoptosis to promote plaque stability via TIPE2/TLR4 axis in high fat diet-fed ApoE mice

Promoting plaque stability is of great significance for prevention and treatment of cardiovascular diseases. 7-difluoromethoxy-5,4'-dimethoxygenistein (DFMG) is a novel active compound synthesized using genistein, which exerts anti-atherosclerotic effect. In this study, we evaluated effects of DFMG on plaque stability in ApoE-/- mice fed with high fat diet (HFD), and explored the molecular mechanism by using ApoE-/-TLR4-/- mice and RAW264.7 cells. Here, we found that DFMG significantly reduced plaque areas, macrophages infiltration and apoptosis, and TLR4 expression in HFD-fed ApoE-/- mice. Meanwhile, DFMG increased collagen fibers, smooth muscle cells and TIPE2 expression in plaques and media. Besides, TLR4 knockout promoted the protective effects of DFMG on plaques. In vitro, DFMG decreased lysophosphatidylcholine (LPC)-induced macrophages apoptosis and TLR4, while upregulated TIPE2. Moreover, TIPE2 reduced TLR4, MyD88, p-NF-κB p65Ser276, cleaved Caspase-3 overproduction, and enhanced effects of DFMG on LPC-induced macrophages. Overall, our study demonstrates that DFMG can promote plaque stability by reducing macrophage apoptosis through TIPE2/TLR4 signaling pathway, which suggests DFMG should be used to develop food additives or drugs for preventing atherosclerosis.