Discovery, synthesis and anti-atherosclerotic activities of a novel selective sphingomyelin synthase 2 inhibitor

• Published in: European journal of medicinal chemistry 2019-02, Vol.163, p.864-882
• Main Authors: Li, Yali, Huang, Taomin, Lou, Bin, Ye, Deyong, Qi, Xiangyu, Li, Xiaoxia, Hu, Shuang, Ding, Tingbo, Chen, Yan, Cao, Yang, Mo, Mingguang, Dong, Jibin, Wei, Min, Chu, Yong, Li, Huiti, Jiang, Xian-Cheng, Cheng, Nengneng, Zhou, Lu
• Format: Article
• Language: English
• Subjects: Animals; ApoE KO mice; Apolipoproteins E - genetics; Atherosclerosis; Atherosclerosis - drug therapy; Benzamides - chemistry; Benzamides - pharmacology; Benzamides - therapeutic use; Cell Line; Drug Discovery; Homeostasis - drug effects; Humans; Inflammation - drug therapy; Inhibitor; Lipid Metabolism; Macrophages - metabolism; Mice; Mice, Knockout; Sphingomyelin synthase 2; Transferases (Other Substituted Phosphate Groups) - antagonists & inhibitors
• ISSN: 0223-5234; 1768-3254
• DOI: 10.1016/j.ejmech.2018.12.028

The sphingomyelin synthase 2 (SMS2) is a potential target for pharmacological intervention in atherosclerosis. However, so far, few selective SMS2 inhibitors and their pharmacological activities were reported. In this study, a class of 2-benzyloxybenzamides were discovered as novel SMS2 inhibitors through scaffold hopping and structural optimization. Among them, Ly93 as one of the most potent inhibitors exhibited IC50 values of 91 nM and 133.9 μM against purified SMS2 and SMS1 respectively. The selectivity ratio of Ly93 was more than 1400-fold for purified SMS2 over SMS1. The in vitro studies indicated that Ly93 not only dose-dependently diminished apoB secretion from Huh7 cells, but also significantly reduced the SMS activity and increased cholesterol efflux from macrophages. Meanwhile, Ly93 inhibited the secretion of LPS-mediated pro-inflammatory cytokine and chemokine in macrophages. The pharmacokinetic profiles of Ly93 performed on C57BL/6J mice demonstrated that Ly93 was orally efficacious. As a potent selective SMS2 inhibitor, Ly93 significantly decreased the plasma SM levels of C57BL/6J mice. Furthermore, Ly93 was capable of dose-dependently attenuating the atherosclerotic lesions in the root and the entire aorta as well as macrophage content in lesions, in apolipoprotein E gene knockout mice treated with Ly93. In conclusion, we discovered a novel selective SMS2 inhibitor Ly93 and demonstrated its anti-atherosclerotic activities in vivo. The preliminary molecular mechanism-of-action studies revealed its function in lipid homeostasis and inflammation process, which indicated that the selective inhibition of SMS2 would be a promising treatment for atherosclerosis. Discovery of a 2-benzyloxybenzamide Ly93 as a novel selective SMS2 inhibitor and the studies on its in vitro and in vivo biological activities. [Display omitted] •2-Benzyloxybenzamides were discovered as novel SMS2 inhibitors.•33 compounds were synthesized and studied SMS2 inhibitory activities for SARs.•Ly93 was a selective SMS2 inhibitor with >1400-fold selectivity for SMS2 over SMS1.•The in vitro assays were performed on Ly93 for the study on the mechanism of action.•Ly93 exhibited significant anti-atherosclerotic activities in the apoE KO mice.