McRobb Lucinda S, McGrath Kristine C Y, Tsatralis Tania, Liong Eleanore C, Tan Joanne T M, Hughes Gillian, Handelsman David J, Heather Alison K
From the Heart Research Institute, Sydney, New South Wales, Australia (L.S.M., K.C.Y.M., T.T., E.C.L., J.T.M.T.); Department of Clinical Medicine, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia (L.S.M.); School of Life Sciences, Faculty of Science, University of Technology Sydney, New South Wales, Australia (K.C.Y.M.); Sydney Medical School (J.T.M.T.) and ANZAC Research Institute (D.J.H.), University of Sydney, New South Wales, Australia; and Department of Physiology, Otago School of Medical Sciences (G.H., A.K.H.) and HeartOtago (A.K.H.), University of Otago, Dunedin, New Zealand.
Arterioscler Thromb Vasc Biol. 2017 Jun;37(6):1127-1137. doi: 10.1161/ATVBAHA.117.309054. Epub 2017 May 4.
Vascular calcification is associated with increased risk of myocardial infarction and stroke. The objective of this work was to examine the ability of 17β-estradiol (E2) to stimulate calcification of vascular smooth muscle cells (VSMC) in vivo, using aged apolipoprotein E-null mice with advanced atherosclerotic lesions, and subsequently to explore underlying mechanisms in vitro.
Silastic E2 capsules were implanted into male and female apolipoprotein E-null mice aged 34 weeks. Plaque and calcified area were measured in the aortic sinus and innominate artery after 8 weeks. Immunohistochemical analysis examined expression of the estrogen receptors (estrogen receptor alpha and estrogen receptor beta [ERβ]). VSMC expression of osteogenic markers was examined using digital polymerase chain reaction. Advanced atherosclerotic lesions were present in all mice at the end of 8 weeks. In both male and female mice, E2 increased calcified area in a site-specific manner in the aortic sinus independently of plaque growth or lipid levels and occurred in association with a site-specific decrease in the proportion of ERβ-positive intimal cells. Calcified lesions expressed collagen I and bone sialoprotein, with decreased matrix Gla protein. In vitro, E2 suppressed ERβ expression and increased VSMC mineralization, demonstrating increased collagen I and II, osteocalcin and bone sialoprotein, and reduced matrix Gla protein and osteopontin. Antagonism or RNA silencing of estrogen receptor alpha, ERβ, or both further increased VSMC mineralization.
We have demonstrated that E2 can drive calcification in advanced atherosclerotic lesions by promoting the differentiation of VSMC to osteoblast-like cells, a process which is augmented by inhibition of estrogen receptor alpha or ERβ activity.
血管钙化与心肌梗死和中风风险增加相关。本研究的目的是使用患有晚期动脉粥样硬化病变的老年载脂蛋白E基因敲除小鼠，检测17β-雌二醇（E2）在体内刺激血管平滑肌细胞（VSMC）钙化的能力，随后在体外探索其潜在机制。
将硅橡胶E2胶囊植入34周龄的雄性和雌性载脂蛋白E基因敲除小鼠体内。8周后测量主动脉窦和无名动脉的斑块和钙化面积。免疫组织化学分析检测雌激素受体（雌激素受体α和雌激素受体β[ERβ]） 的表达。使用数字聚合酶链反应检测VSMC中成骨标志物的表达。8周结束时，所有小鼠均出现晚期动脉粥样硬化病变。在雄性和雌性小鼠中，E2均以位点特异性方式增加主动脉窦的钙化面积，与斑块生长或血脂水平无关，且与ERβ阳性内膜细胞比例的位点特异性降低有关。钙化病变表达I型胶原蛋白和骨唾液蛋白，基质Gla蛋白减少。在体外，E2抑制ERβ表达并增加VSMC矿化，表现为I型和II型胶原蛋白、骨钙素和骨唾液蛋白增加，基质Gla蛋白和骨桥蛋白减少。雌激素受体α、ERβ或两者的拮抗或RNA沉默进一步增加了VSMC矿化。
我们已经证明，E2可以通过促进VSMC向成骨样细胞分化来驱动晚期动脉粥样硬化病变中的钙化，这一过程通过抑制雌激素受体α或ERβ活性而增强。
