title: Ultraviolet B exposure of peripheral blood mononuclear cells of patients with systemic lupus erythematosus inhibits DNA methylation.
abstract: Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease, in which sunlight (especially ultraviolet B (UVB) 290-320 nm) is known to induce exacerbation of disease. DNA methylation regulates gene expression, and hypomethylation is associated with abnormal cell function in SLE. The purpose of this study was to investigate the effect of UVB on DNA methylation in SLE and its significance in the pathogenesis of SLE. Forty-five patients with SLE and 20 healthy controls were enrolled in the study, which involved the investigation of DNA methylation and DNA methyltransferase 1 (DNMT1) of peripheral blood mononuclear cells with UVB irradiation. Our results demonstrate the following: The level of DNA methylation in patients with SLE was lower than that in the control group. DNA methylation was decreased after UVB irradiation at different dosages especially in patients with marlar rashes and leucopenia, but no significant difference was observed in the DNMT1 mRNA expression. DNA methylation levels in patients with active SLE were more sensitive to UVB. In conclusion, UVB exposure is able to inhibit DNA methylation, which subsequently takes part in the pathogenesis of SLE.
authors.affiliation: Department of Rheumatology and Immunology, Affiliated Anhui Provincial Hospital, Anhui Medical University, Hefei 230001, China. wangguosheng@hotmail.com
authors.forename: G S
authors.initials: GS
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Zhang
authors.forename: X P
authors.initials: XP
authors.lastname: Li
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: W
authors.initials: W
authors.lastname: Chen
authors.forename: M
authors.initials: M
authors.lastname: Kan
authors.forename: Y M
authors.initials: YM
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation / Q000528:radiation effects*; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000528:radiation effects*; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000188:drug therapy / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D014466:Ultraviolet Rays; D055815:Young Adult
chemical_list: D005938:Glucocorticoids; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619380:DNMT1 protein, human