Flow-dependent epigenetic DNA methylation regulates endothelial gene expression and atherosclerosis
Jessilyn Dunn, … , I. King Jordan, Hanjoong Jo
Jessilyn Dunn, … , I. King Jordan, Hanjoong Jo
Published May 27, 2014
Citation Information: J Clin Invest. 2014;124(7):3187-3199. https://doi.org/10.1172/JCI74792.
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Research Article Vascular biology

Flow-dependent epigenetic DNA methylation regulates endothelial gene expression and atherosclerosis

Abstract

In atherosclerosis, plaques preferentially develop in arterial regions of disturbed blood flow (d-flow), which alters endothelial gene expression and function. Here, we determined that d-flow regulates genome-wide DNA methylation patterns in a DNA methyltransferase–dependent (DNMT-dependent) manner. Induction of d-flow by partial carotid ligation surgery in a murine model induced DNMT1 in arterial endothelium. In cultured endothelial cells, DNMT1 was enhanced by oscillatory shear stress (OS), and reduction of DNMT with either the inhibitor 5-aza-2′-deoxycytidine (5Aza) or siRNA markedly reduced OS-induced endothelial inflammation. Moreover, administration of 5Aza reduced lesion formation in 2 mouse models of atherosclerosis. Using both reduced representation bisulfite sequencing (RRBS) and microarray, we determined that d-flow in the carotid artery resulted in hypermethylation within the promoters of 11 mechanosensitive genes and that 5Aza treatment restored normal methylation patterns. Of the identified genes, HoxA5 and Klf3 encode transcription factors that contain cAMP response elements, suggesting that the methylation status of these loci could serve as a mechanosensitive master switch in gene expression. Together, our results demonstrate that d-flow controls epigenomic DNA methylation patterns in a DNMT-dependent manner, which in turn alters endothelial gene expression and induces atherosclerosis.

Authors

Jessilyn Dunn, Haiwei Qiu, Soyeon Kim, Daudi Jjingo, Ryan Hoffman, Chan Woo Kim, Inhwan Jang, Dong Ju Son, Daniel Kim, Chenyi Pan, Yuhong Fan, I. King Jordan, Hanjoong Jo

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Figure 3

Treatment with the DNMT inhibitor 5Aza inhibits atherosclerosis.

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Treatment with the DNMT inhibitor 5Aza inhibits atherosclerosis. (A and ...
(A and B) Acute, partial carotid ligation model of atherosclerosis: ApoE–/– mice were given daily i.p. injections of 5Aza for 1 week at 0.1, 0.2, or 0.4 mg/kg/d, or saline as a vehicle control. Then, partial carotid ligation was done, and mice were fed a Western diet while continuing the same 5Aza treatment for 3 more weeks. Frozen sections of the carotid arteries were examined by oil red O staining (scale bars: 200 μm) (A), and plaque area quantification (mm2) was done using ImageJ (B) (n = 13 each, data are shown as the mean ± SEM. **P < 0.005). (C and D) Chronic, diet-induced atherosclerosis model: ApoE–/– mice were fed a Western diet (without partial ligation surgery) and treated with 5Aza (vehicle or 0.2 mg/kg/d, daily i.p. injections) for 3 months. Aortic arches were longitudinally sectioned and stained with oil red O (scale bars: 1 mm) (C), and plaque area (mm2) was quantified (D) (n = 10 for vehicle, n = 9 for 5Aza, mean ± SEM. **P < 0.005).