OxLDL up-regulates microRNA-29b, leading to epigenetic modifications of MMP-2/MMP-9 genes: a novel mechanism for cardiovascular diseases.
MicroRNAs (miRNAs), small noncoding RNAs, can control gene expression by binding to their target genes for degradation and/or translational repression. Epigenetic mechanisms are defined as heritable changes in gene expression that do not involve coding sequence modifications. Both mechanisms play an important role in maintaining physiological functions and are also related to disease development. However, few studies report that miRNA-mediated epigenetic regulations are involved in atherosclerosis. In the present study, oxidized low-density lipoprotein (oxLDL) significantly increased primary human aortic smooth muscle cell (HASMC) migration through MMP-2/MMP-9 up-regulation associated with decreased DNA methylation levels. Either mRNA or protein level of DNA methyltransferase 3b (DNMT3b) showed a dose-dependent down-regulation in oxLDL-mediated HASMCs. Knockdown DNMT3b expression enhanced oxLDL-induced DNA demethylation levels of MMP-2/MMP-9. The expression of miRNA-29b (miR-29b), directly targeting DNMT3b, was up-regulated by oxLDL treatment in a dose-dependent manner. OxLDL-mediated MMP-2/MMP-9 up-regulation, DNMT3b down-regulation, and DNA demethylation were all attenuated after knockdown miR-29b expression by antagomiR-29b. We find that oxLDL can up-regulate miR-29b expression, resulting in DNMT3b down-regulation in HASMCs and epigenetically regulated MMP-2/MMP-9 genes involved in cell migration. These results show that miRNA-mediated epigenetic regulation may be a novel mechanism in atherosclerosis.
Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
Ku-Chung
KC
Chen
Yung-Song
YS
Wang
Ching-Yu
CY
Hu
Wei-Chiao
WC
Chang
Yi-Chu
YC
Liao
Chia-Yen
CY
Dai
Suh-Hang Hank
SH
Juo
D001011:Aorta / Q000166:cytology; D015153:Blotting, Western; D002318:Cardiovascular Diseases / Q000235:genetics / Q000378:metabolism*; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D044127:Epigenesis, Genetic / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D006801:Humans; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D013058:Mass Spectrometry; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000097584:DNA Methyltransferase 3B
D004248:DNA (Cytosine-5-)-Methyltransferases; D008077:Lipoproteins, LDL; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D035683:MicroRNAs; D000097584:DNA Methyltransferase 3B; C099252:oxidized low density lipoprotein