Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA 02111, USA.
Arterioscler Thromb Vasc Biol. 2013 Feb;33(2):257-65. doi: 10.1161/ATVBAHA.112.300200. Epub 2012 Nov 21.
Estradiol (E2) regulates gene transcription by activating estrogen receptor-α and estrogen receptor-β. Many of the genes regulated by E2 via estrogen receptors are repressed, yet the molecular mechanisms that mediate E2-induced gene repression are currently unknown. We hypothesized that E2, acting through estrogen receptors, regulates expression of microRNAs (miRs) leading to repression of expression of specific target genes.
Here, we report that E2 significantly upregulates the expression of 26 miRs and downregulates the expression of 6 miRs in mouse aorta. E2-mediated upregulation of one of these miRs, miR-203, was chosen for further study. In cultured vascular smooth muscle cells (VSMC), E2-mediated upregulation of miR-203 is mediated by estrogen receptor-α (but not estrogen receptor-β) via transcriptional upregulation of the primary miR. We demonstrate that the transcription factors Zeb-1 and AP-1 play critical roles in mediating E2-induced upregulation of miR-203 transcription. We show further that miR-203 mediates E2-induced repression of Abl1, and p63 protein abundance in VSMC. Finally, knocking-down miR-203 abolishes E2-mediated inhibition of VSMC proliferation, and overexpression of miR-203 inhibits cultured VSMC proliferation, but not vascular endothelial cell proliferation.
Our findings demonstrate that E2 regulates expression of miRs in the vasculature and support the estrogen receptors-dependent induction of miRs as a mechanism for E2-mediated gene repression. Furthermore, our findings demonstrate that miR-203 contributes to E2-induced inhibition of VSMC proliferation and highlight the potential of miR-203 as a therapeutic agent in the treatment of proliferative cardiovascular diseases.
雌二醇（E2）通过激活雌激素受体-α和雌激素受体-β来调节基因转录。许多受 E2 调节的基因通过雌激素受体被抑制，但介导 E2 诱导基因抑制的分子机制目前尚不清楚。我们假设 E2 通过雌激素受体调节 microRNAs（miRs）的表达，导致特定靶基因表达的抑制。
在这里，我们报告 E2 显著上调了小鼠主动脉中 26 个 miR 的表达，并下调了 6 个 miR 的表达。E2 介导的其中一个 miR，miR-203 的上调被选为进一步研究。在培养的血管平滑肌细胞（VSMC）中，E2 介导的 miR-203 的上调是通过雌激素受体-α（而不是雌激素受体-β）通过对初级 miR 的转录上调来介导的。我们证明转录因子 Zeb-1 和 AP-1 在介导 E2 诱导的 miR-203 转录上调中起着关键作用。我们进一步表明，miR-203 介导 E2 诱导的 Abl1 和 p63 蛋白丰度在 VSMC 中的下调。最后，敲低 miR-203 可消除 E2 介导的 VSMC 增殖抑制，而过表达 miR-203 可抑制培养的 VSMC 增殖，但不抑制血管内皮细胞增殖。
我们的研究结果表明 E2 在血管中调节 miRs 的表达，并支持雌激素受体依赖性诱导 miRs 作为 E2 介导基因抑制的机制。此外，我们的研究结果表明 miR-203 有助于 E2 诱导的 VSMC 增殖抑制，并强调了 miR-203 作为治疗增殖性心血管疾病的治疗剂的潜力。
