2-Methoxyestradiol blocks the RhoA/ROCK1 pathway in human aortic smooth muscle cells.
2-Methoxyestradiol (2-ME), a metabolite of estradiol with little affinity for estrogen receptors, inhibits proliferation of vascular smooth muscle cells; however, the molecular mechanisms underlying this effect are incompletely understood. Our previous work shows that 2-ME inhibits initiation (blocks phosphorylation of ERK and Akt) and progression (reduces cyclin expression and increases expression of cyclin inhibitors) of the mitogenic pathway and interferes with mitosis (disrupts tubulin organization). Because the RhoA/ROCK1 pathway (RhoA → ROCK1 → myosin phosphatase targeting subunit → myosin light chain) is involved in cytokinesis, herein we tested the concept that 2-ME also blocks the RhoA/ROCK1 pathway. Because of the potential importance of 2-ME for preventing/treating vascular diseases, experiments were conducted in female human aortic vascular smooth muscle cells. Microarray transcriptional profiling suggested an effect of 2-ME on the RhoA/ROCK1 pathway. Indeed, 2-ME blocked mitogen-induced GTP-bound RhoABC expression and membrane-bound RhoA, suggesting interference with the activation of RhoA. 2-ME also reduced ROCK1 expression, suggesting reduced production of the primary downstream signaling kinase of the RhoA pathway. Moreover, 2-ME inhibited RhoA/ROCK1 pathway downstream signaling, including phosphorylated myosin phosphatase targeting subunit and myosin light chain; the ROCK1 inhibitor H-1152 mimicked these effects of 2-ME; both 2-ME and H-1152 blocked cytokinesis. 2-ME also reduced the expression of tissue factor, yet another downstream signaling component of the RhoA/ROCK1 pathway. We conclude that 2-ME inhibits the pathway RhoA → ROCK1 → myosin phosphatase targeting subunit → myosin light chain, and this likely contributes to the reduced cytokinesis in 2-ME treated HASMCs.
Department of Reproductive Endocrinology, University Hospital Zurich, Zurich, Switzerland;
Lisa
L
Rigassi
Department of Reproductive Endocrinology, University Hospital Zurich, Zurich, Switzerland;
Federica
F
Barchiesi Bozzolo
Department of Anesthesiology and Pain Medicine and Cardiovascular Research Centre, University of Alberta, Edmonton, Alberta, Canada; and.
Eliana
E
Lucchinetti
Department of Anesthesiology and Pain Medicine and Cardiovascular Research Centre, University of Alberta, Edmonton, Alberta, Canada; and.
Michael
M
Zaugg
Preclinical Pharma Research 60/209, F Hoffmann-La-Roche, Basel, Switzerland.
Jürgen
J
Fingerle
Department of Reproductive Endocrinology, University Hospital Zurich, Zurich, Switzerland;
Marinella
M
Rosselli
Department of Reproductive Endocrinology, University Hospital Zurich, Zurich, Switzerland;
Bruno
B
Imthurn
Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania;
Edwin K
EK
Jackson
Department of Reproductive Endocrinology, University Hospital Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland; raghvendra.dubey@usz.ch.
Raghvendra K
RK
Dubey
D000077584:2-Methoxyestradiol; D001011:Aorta / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D048749:Cytokinesis / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D054460:rho-Associated Kinases / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
C066737:RHOA protein, human; D004958:Estradiol; D000077584:2-Methoxyestradiol; C515851:ROCK1 protein, human; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein
2-methoxyestradiol; ROCK1; RhoA; cytokinesis; myosin light chain; myosin phosphatase targeting subunit