Open AccessDNA Methylation of miR-122 Aggravates Oxidative Stress in Colitis Targeting SELENBP1 Partially by p65NF-κB Signaling
Author(s) -
Jianan Bai,
Junchi Yu,
Jintian Wang,
Bingyan Xue,
Na He,
Ye Tian,
Lixia Yang,
Yipin Wang,
Yanyan Wang,
Qiyun Tang
Publication year - 2019
Publication title -
oxidative medicine and cellular longevity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.494
H-Index - 93
eISSN - 1942-0900
pISSN - 1942-0994
DOI - 10.1155/2019/5294105
Subject(s) - oxidative stress , dna methylation , cancer research , methylation , chemistry , microrna , colitis , microbiology and biotechnology , biology , immunology , gene expression , biochemistry , dna , gene
Aberrant microRNA (miRNA) expressions contribute to the development and progression of various diseases, including Crohn's disease (CD). However, the accurate mechanisms of miRNAs in CD are definitely unclear. We employed colonic tissue samples from normal volunteers and CD patients, an acute mice colitis model induced by 2,4,6-trinitro-benzene-sulfonic acid (TNBS), and a cellular oxidative stress model induced by H 2 O 2 in HT-29 cells to determine the effects of oxidative stress on expressions of miR-122, selenium-binding protein 1 (SELENBP1, SBP1), p65 nuclear factor κ B (p65NF- κ B) signaling, and DNA methylation. We found that SBP1 was mainly located on epithelial cells and was significantly increased in patients with active CD. SBP1 was the target gene of miR-122. miR-122 expression was downregulated while SBP1 expression was upregulated under TNBS-induced colitis or oxidative stress. Pre-miR-122 or siRNA SBP1 (si-SBP1) treatment ameliorated acute TNBS-induced colitis and H 2 O 2 -induced oxidative stress. Cotreatment of pre-miR-122 and si-SBP1 enhanced these effects. Besides, pre-miR-122 and si-SBP1 obviously activated the p65NF- κ B signaling by phosphorylation of I κ B α . Bisulfite sequencing of the CpG islands in the promoter region of miR-122 showed that CpG methylation was significantly increased under oxidative stress. Treating cells with 5′-AZA which was well known as a DNA-demethylating agent significantly increased miR-122 expression. Our results suggest that oxidative stress-induced DNA methylation of miR-122 aggravates colitis targeting SELENBP1 partially by p65NF- κ B signaling and may promote the progression of CD.