title: Hypomethylation of HLA-DRB1 and its clinical significance in psoriasis.
abstract: Increasing evidences indicate that the abnormal DNA methylation is involved in the pathogenesis of psoriasis. A number of SNPs in HLA-DRB1 have been found being associated with the risk of psoriasis, however it is unclear that metylation status within HLA-DRB1 in psoriasis. Here, DNA and RNA were obtained from epidermis of 56 patients with plaque psoriasis and 28 healthy volunteers served as the control group. For the first time, we discovered mean methylation rate for HLA-DRB1 is 52.2%, 64.3% and 68.1% in epidermis from psoriatic lesions, psoriatic non-lesions and healthy controls, respectively. HLA-DRB1 methylation in psoriatic lesions is significantly lower than in psoriatic non-lesions (t = 13.077, p < 0.001). However, there is no significant difference for HLA-DRB1 methylation between in psoriatic non-lesions and in healthy controls (t = 1.046, p = 0.299). HLA-DRB1 methylation in psoriatic lesions is negatively correlated to PASI score (r = -0.431, p = 0.001). HLA-DRB1 methylation in psoriatic lesions of the patients with onset age≤18 years is significantly lower than the other patients (t = 3.968, p < 0.001). Meanwhile, HLA-DRB1 mRNA expression is significantly increased in psoriatic lesions comparing to psoriatic non-lesions (t = 12.119, p < 0.001). There are no significant difference for HLA-DRB1 mRNA expression between in psoriatic non-lesions and in healthy controls (t = 1.172, p = 0,245). Moreover, HLA-DRB1 mRNA expression is negatively associated with HLA-DRB1 methylation in psoriatic lesions (r = 0.932, p < 0.001). In conclusions, our results showed hypomethylation of HLA-DRB1 is associated with HLA-DRB1 mRNA expression and severity of the disease, indicating that hypomethylation of HLA-DRB1 may play roles in the pathogenesis of psoriasis.
authors.affiliation: Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.
authors.forename: Wenkai
authors.initials: W
authors.lastname: Zong
authors.affiliation: Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Ge
authors.affiliation: Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Han
authors.affiliation: Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.
authors.forename: Xueyuan
authors.initials: X
authors.lastname: Yang
authors.affiliation: Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019175:DNA Methylation; D004817:Epidermis / Q000378:metabolism / Q000473:pathology; D005260:Female; D015870:Gene Expression; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D059811:HLA-DRB1 Chains / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011401:Promoter Regions, Genetic / Q000235:genetics; D011565:Psoriasis / Q000235:genetics* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA / Q000379:methods; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D059811:HLA-DRB1 Chains
keywords: HLA-DRB1; gene methylation; mRNA; psoriasis