PMID: Br J Pharmacol. 2021 04 ;178(7):1524-1540. Epub 2021 Feb 15. PMID: 33474722 Abstract Title: Harmine alleviates atherogenesis by inhibiting disturbed flow-mediated endothelial activation via protein tyrosine phosphatase PTPN14 and YAP. Abstract: BACKGROUND AND PURPOSE: Disturbed flow induces endothelial dysfunction and contributes to uneven distribution of atherosclerotic plaque. Emerging evidence suggests that harmine, a natural constituent of extracts of Peganum harmala, has potent beneficial activities. Here, we investigated if harmine has an atheroprotective role under disturbed flow and the underlying mechanism.EXPERIMENTAL APPROACH: Mice of ApoE, LDLR, and endothelial cell (EC)-specific overexpression of yes-associated protein (YAP) in ApoEbackground were fed with a Western diet and given harmine for 4 weeks. Atherosclerotic lesion size, cellular composition, and expression of inflammatory genes in the aortic roots were assessed. HUVECs were treated with oscillatory shear stress (OSS) and harmine and also used for proteomic analysis.KEY RESULTS: Harmine retarded atherogenesis in both ApoEand LDLRmice by inhibiting the endothelial inflammatory response. Mechanistically, harmine blocked OSS-induced YAP nuclear translocation and EC activation by reducing phosphorylation of YAP at Y357. Overexpression of endothelial YAP blunted the beneficial effects of harmine in mice. Proteomic study revealed that protein tyrosine phosphatase non-receptor type 14 (PTPN14) could bind to YAP. Moreover, harmine increased PTPN14 expression by stabilizing its protein level and inhibiting its degradation in proteasomes. PTPN14 knockdown blocked the effects of harmine on YAPand EC activation. Finally, overexpression of PTPN14 mimicked the effects of harmine and ameliorated atherosclerosis, and knockdown of PTPN14 blunted the atheroprotective effects of harmine and accelerated atherosclerosis, in a partial ligation mouse model.CONCLUSION AND IMPLICATIONS: Harmine alleviated OSS-induced EC activation via a PTPN14/YAPpathway and had a potent atheroprotective role.
read more
read more