Cholesterol plays a key role in membrane protein function and signaling in endothelial cells. Thus, disturbing cholesterol trafficking is an effective approach for inhibiting angiogenesis. We recently identified astemizole (AST), an antihistamine drug, as a cholesterol trafficking inhibitor from a phenotypic screen. In this study, we found that AST induced cholesterol accumulation in the lysosome by binding to the sterol-sensing domain of Niemann-Pick disease, type C1 (NPC1), a lysosomal surface protein responsible for cholesterol transport. Inhibition of cholesterol trafficking by AST led to the depletion of membrane cholesterol, causing SREBP1 nuclear localization. The depletion of membrane cholesterol resulted in dissociation of mammalian target of rapamycin (mTOR) from the lysosomal surface and inactivation of mTOR signaling. These effects were effectively rescued by addition of exogenous cholesterol. AST inhibited endothelial cell proliferation, migration and tube formation in a cholesterol-dependent manner. Furthermore, AST inhibited zebrafish angiogenesis in a cholesterol-dependent manner. Together, our data suggest that AST is a new class of NPC1 antagonist that inhibits cholesterol trafficking in endothelial cells and angiogenesis.
Bibliographical noteFunding Information:
This study was supported by the Science and Technology Development Fund (FDCT) of Macau SAR (FDCT/119/2013/A3 and FDCT/024/2015/A1 to J.S.S); Multi-Year Research Grant of the University of Macau (MYRG2015-00181-FHS and MYRG2017-00176-FHS to J.S.S); NRF grant (2015K1A1A2028365 and 2015M3A9B6027818 to H.J.K). Support from National Cancer Institute (R01CA184103 to J.O.L.), the Flight Attendant Medical Research Institute (J.O.L.), and the Johns Hopkins Institute for Clinical and Translational Research, which is funded in part by Grant UL1 TR 001079 from the National Center for Advancing Translational Sciences (NCATS) is also gratefully acknowledged.
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics
- Applied Microbiology and Biotechnology
- Molecular Biology
- Developmental Biology
- Cell Biology