Zawadzki Christophe, Chatelain Nicolas, Delestre Marianne, Susen Sophie, Quesnel Bruno, Juthier Francis, Jeanpierre Emmanuelle, Azzaoui Richard, Corseaux Delphine, Breyne Joke, Torpier Gérard, Staels Bart, Van Belle Eric, Jude Brigitte
Université de Lille 2, EA-2693, F-59045 Lille, France.
Atherosclerosis. 2009 Jun;204(2):e4-14. doi: 10.1016/j.atherosclerosis.2008.10.009. Epub 2008 Oct 19.
The tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type serine-protease inhibitor which is expressed in atherosclerotic plaques. Epigenetic regulation of the TFPI-2 gene, through methylation of CpG islands, has been advocated in cancer. We hypothesized that TFPI-2 gene methylation could regulate TFPI-2 expression in atherosclerosis.
We used Methylation Specific PCR (MSP) and pyrosequencing in order to identify 18 CpG of the TFPI-2 promoter, in 59 carotid atherosclerotic plaques and 26 control mammary arteries.
MSP showed methylation of the TFPI-2 gene (MSP+) in 16 plaques (27%), while no methylation (MSP-) was found in control arteries. Pyrosequencing confirmed that MSP+ plaques presented higher methylation levels than MSP- ones and arteries (p=0.03 and 0.01). Moreover, the TFPI-2 mRNA levels were lower in methylated plaques than in unmethylated ones and than in arteries (p=0.04 and <0.0001). The methylated plaques contained less lipids and macrophage infiltration than unmethylated ones. Their TFPI-2 immunoreactivity was mainly detected in the macrophages located in the media on the adventitial side, rather than in the lipid-rich core.
Methylation of the TFPI-2 gene takes place in atherosclerotic plaques and is associated with decreased TFPI-2 expression. The place of this process in atherosclerosis progression remains to be investigated.
组织因子途径抑制剂-2（TFPI-2）是一种Kunitz型丝氨酸蛋白酶抑制剂，在动脉粥样硬化斑块中表达。在癌症中，通过CpG岛甲基化对TFPI-2基因进行表观遗传调控已得到证实。我们推测TFPI-2基因甲基化可能在动脉粥样硬化中调节TFPI-2的表达。
我们使用甲基化特异性PCR（MSP）和焦磷酸测序来鉴定59个颈动脉粥样硬化斑块和26个对照乳腺动脉中TFPI-2启动子的18个CpG。
MSP显示16个斑块（27%）中TFPI-2基因甲基化（MSP+），而对照动脉中未发现甲基化（MSP-）。焦磷酸测序证实，MSP+斑块的甲基化水平高于MSP-斑块和对照动脉（p=0.03和0.01）。此外，甲基化斑块中的TFPI-2 mRNA水平低于未甲基化斑块和对照动脉（p=0.04和<0.0001）。甲基化斑块比未甲基化斑块含有更少的脂质和巨噬细胞浸润。它们的TFPI-2免疫反应性主要在位于外膜侧中膜的巨噬细胞中检测到，而不是在富含脂质的核心中。
TFPI-2基因甲基化发生在动脉粥样硬化斑块中，并与TFPI-2表达降低有关。这一过程在动脉粥样硬化进展中的作用仍有待研究。
