Methylation of the estrogen receptor-alpha gene promoter is selectively increased in proliferating human aortic smooth muscle cells.
Methylation of the estrogen receptor-alpha gene promoter is selectively increased in proliferating human aortic smooth muscle cells.
复制标题
在增殖的人主动脉平滑肌细胞中，雌激素受体-α基因启动子的甲基化选择性增加。
DOI：
10.1016/s0008-6363(00)00004-3
复制
发表时间：
2000
影响因子：
10.8
通讯作者：
Goldschmidt-Clermont,PJ
中科院分区：
文献类型：
--
作者：
Ying,AK;Hassanain,HH;Roos,CM;Smiraglia,DJ;Issa,JJ;Michler,RE;Caligiuri,M;Plass,C;Goldschmidt-Clermont,PJ
目的：动脉粥样硬化是一个多因素导致中、大口径动脉进行性闭塞的过程。动脉粥样硬化过程的关键步骤是血管平滑肌细胞增殖和迁移到动脉导管的内膜层中。已知平滑肌细胞的表型一旦在内膜内就从收缩性转变为去分化性，但这种转变在基因组水平上的调节是未知的。雌激素已被证明可以调节癌细胞和血管细胞的细胞增殖。然而，雌激素受体-α（ERα）基因启动子甲基化可阻断ER α的表达，从而拮抗雌激素对细胞增殖的调节作用。方法：采用Southern印迹杂交、Cobra酶切分析和RLGS-M酶切标记基因组扫描技术，检测人主动脉平滑肌细胞ER α的甲基化状态。（正常主动脉组织，收缩表型），或从主动脉中分离并在体外培养的相同细胞（去分化表型）。我们提供的证据表明，相对于在非动脉粥样硬化动脉瘤中研究的相同细胞，在显示增殖表型的平滑肌细胞中ER α的甲基化发生了改变。因此，ER α启动子在原位（正常主动脉）没有甲基化，但在增殖的主动脉平滑肌细胞中甲基化。使用筛选技术RLGS-M，我们发现与平滑肌细胞表型转换相关的甲基化改变似乎不需要甲基转移酶的活性提高，并且似乎对ER α和有限的基因池具有选择性，这些基因的CpG岛变得去甲基化或从头甲基化。我们的数据支持主动脉平滑肌细胞的基因组对环境条件有反应的概念，并且DNA甲基化，特别是ER α的甲基化，可能有助于在这些细胞中观察到的表型转换。
Objective:Atherosclerosis is a multigenic process leading to the progressive occlusion of arteries of mid to large caliber. A key step of the atherogenic process is the proliferation and migration of vascular smooth muscle cells into the intimal layer of the arterial conduit. The phenotype of smooth muscle cells, once within the intima, is known to switch from contractile to de-differentiated, yet the regulation of this switch at the genomic level is unknown. Estrogen has been shown to regulate cell proliferation both for cancer cells and for vascular cells. However, methylation of the estrogen receptor-α gene (ERα) promoter blocks the expression ofERα, and thereby can antagonize the regulatory effect of estrogen on cell proliferation. We sought to determine whether methylation of theERαis differentially and selectively regulated in contractile versus de-differentiated arterial smooth muscle cells.Methods:We used Southern blot assay, combined bisulfite restriction analysis (Cobra) and restriction landmark genome scanning (RLGS-M) to determine the methylation status ofERαin human aortic smooth muscle cells, either in situ (normal aortic tissue, contractile phenotype), or the same cells explanted from the aorta and cultured in vitro (de-differentiated phenotype).Results:We provide evidence that methylation of theERαin smooth muscle cells that display a proliferative phenotype is altered relative to the same cells studied within the media of non-atherosclerotic aortas. Thus, theERαpromoter does not appear to be methylated in situ (normal aorta), but becomes methylated in proliferating aortic smooth muscle cells. Using a screening technique, RLGS-M, we show that alteration in methylation associated with the smooth muscle cell phenotypic switch does not seem to require heightened activity of the methyltransferase enzyme, and appears to be selective for theERαand a limited pool of genes whose CpG island becomes either demethylated or de novo methylated.Conclusions:Our data support the concept that the genome of aortic smooth muscle cells is responsive to environmental conditions, and that DNA methylation, in particular methylation of theERα, could contribute to the switch in phenotype observed in these cells.