title: Effect of 27nt small RNA on endothelial nitric-oxide synthase expression.
abstract: We have reported previously that the 27nt repeat polymorphism in endothelial nitric-oxide synthase (eNOS) intron 4--a source of 27nt small RNA--inhibits eNOS expression. In the current study, we have investigated how 27nt small RNA suppresses eNOS expression. Using a chromatin immunoprecipitation assay, we examined histone acetylation in the 27nt repeat element of eNOS intron 4, the promoter region up to -1486 bp, and the 5' enhancer region (-4583/-4223bp) in human aortic endothelial cells (HAECs) treated with 27nt RNA duplex. 27nt RNA duplex induced hyperacetylation in H3 (lysine8, 12, and 23) and H4 (lysine 9 and 12) at the 27nt repeat element, which then interacted with nuclear actin, histone deacetylase 3 (HDAC3), and NonO proteins. In contrast, the histone H3 and H4 became hypoacetylated at the eNOS core promoter. HAECs treated with 27nt RNA duplex had reduced eNOS expression, but treatment with either HDAC3 small interfering RNA or NonO siRNA significantly attenuated the 27nt small RNA-induced suppression. We further found that 27nt small RNA induced DNA methylation in a region approximately 750nt upstream of the intron 4 repeats, and a methyltransferase inhibitor reversed the effect on methylation and eNOS expression. Our study demonstrates that 27nt small RNA may suppress eNOS expression by altering histone acetylation and DNA methylation in regions adjacent to the 27nt repeat element and core promoter.
authors.affiliation: Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Shandong University, Qilu Hospital, Jinan, Shandong 250012, China.
authors.forename: Ming-Xiang
authors.initials: MX
authors.lastname: Zhang
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.forename: Ying H
authors.initials: YH
authors.lastname: Shen
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Xiao-Nan
authors.initials: XN
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Coselli
authors.forename: Xing Li
authors.initials: XL
authors.lastname: Wang
mesh_terms: D001011:Aorta / Q000166:cytology; D002467:Cell Nucleus / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D019175:DNA Methylation; D004730:Endothelium, Vascular / Q000166:cytology; D015971:Gene Expression Regulation, Enzymologic; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D007438:Introns; D052250:Nitric Oxide Synthase Type III / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012313:RNA / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism
chemical_list: D006657:Histones; D034741:RNA, Small Interfering; D012313:RNA; D052250:Nitric Oxide Synthase Type III