From the INSERM-UPS UMR U1048, Institut des Maladies Métaboliques et Cardiovasculaires (M.A., C.F., R.Z., M.B., R.S., T.A., F.B., P.G., H.L., C.F., J.-F.A., F.L.), Université de Toulouse, France.
Institut National de la Santé et de la Recherche Médicale U1083, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 46 015, Université d'Angers, France (E.V., J.F., A.-L.G., D.H.).
Arterioscler Thromb Vasc Biol. 2020 Sep;40(9):2143-2158. doi: 10.1161/ATVBAHA.120.314159. Epub 2020 Jul 9.
ERα (estrogen receptor alpha) exerts nuclear genomic actions and also rapid membrane-initiated steroid signaling. The mutation of the cysteine 451 into alanine in vivo has recently revealed the key role of this ERα palmitoylation site on some vasculoprotective actions of 17β-estradiol (E2) and fertility. Here, we studied the in vivo role of the arginine 260 of ERα which has also been described to be involved in its E2-induced rapid signaling with PI-3K (phosphoinositide 3-kinase) as well as G protein in cultured cell lines. Approach and Results: We generated a mouse model harboring a point mutation of the murine counterpart of this arginine into alanine (R264A-ERα). In contrast to the , the females are fertile with standard hormonal serum levels and normal control of hypothalamus-pituitary ovarian axis. Although R264A-ERα protein abundance was normal, the well-described membrane ERα-dependent actions of estradiol, such as the rapid dilation of mesenteric arteries and the acceleration of endothelial repair of carotid, were abrogated in mice. In striking contrast, E2-regulated gene expression was highly preserved in the uterus and the aorta, revealing intact nuclear/genomic actions in response to E2. Consistently, 2 recognized nuclear ERα-dependent actions of E2, namely atheroma prevention and flow-mediated arterial remodeling were totally preserved.
These data underline the exquisite role of arginine 264 of ERα for endothelial membrane-initiated steroid signaling effects of E2 but not for nuclear/genomic actions. This provides the first model of fertile mouse with no overt endocrine abnormalities with specific loss-of-function of rapid ERα signaling in vascular functions.
雌激素受体 α（ERα）发挥核基因组作用，也发挥快速的膜起始甾体信号作用。体内将半胱氨酸 451 突变为丙氨酸的突变最近揭示了这个 ERα 棕榈酰化位点在 17β-雌二醇（E2）和生育力的一些血管保护作用中的关键作用。在这里，我们研究了 ERα 的精氨酸 260 的体内作用，该精氨酸也被描述为参与其 E2 诱导的快速信号转导，与 PI-3K（磷酸肌醇 3-激酶）以及培养细胞系中的 G 蛋白。方法和结果：我们生成了一个携带这种精氨酸的小鼠对应物突变为丙氨酸的点突变（R264A-ERα）的小鼠模型。与野生型相比，雌性具有正常的激素血清水平和下丘脑-垂体-卵巢轴的正常控制，是可育的。虽然 R264A-ERα 蛋白丰度正常，但雌激素的典型的膜 ERα 依赖性作用，如肠系膜动脉的快速扩张和颈动脉内皮修复的加速，在 小鼠中被阻断。引人注目的是，E2 调节的基因表达在子宫和主动脉中高度保留，揭示了对 E2 的完整核/基因组作用。一致地，E2 的 2 个公认的核 ERα 依赖性作用，即动脉粥样硬化预防和血流介导的动脉重塑，完全保留。结论：这些数据强调了 ERα 的精氨酸 264 对 E2 的内皮膜起始甾体信号作用的精细作用，但对核/基因组作用没有作用。这提供了第一个具有无明显内分泌异常的可育小鼠模型，具有血管功能中快速 ERα 信号的特异性功能丧失。
