Dataset Information

Global methylation analysis of psoriatic (involved and uninvolved) and control skin

ABSTRACT: Psoriasis is a chronic inflammatory immune-mediated disorder affecting the skin and other organs including joints. Over 1,300 transcripts are altered in psoriatic involved skin compared to normal skin. Global epigenetic profiles of psoriatic skin have not been described. Here we describe the first genome-wide study of altered CpG methylation in psoriatic skin. We determined the methylation levels at 27,578 CpG sites in skin samples from individuals with psoriasis (12 involved, 8 uninvolved) and 10 unaffected individuals. CpG methylation of involved skin differed from normal skin at 1,108 sites. Twelve mapped to the epidermal differentiation complex, upstream or within genes that are highly up-regulated in psoriasis. Hierarchical clustering of 50 of the top differentially methylated (DM) sites separated psoriatic from normal skin samples. CpG sites where methylation was correlated with gene expression are reported. Sites with inverse correlations between methylation and nearby gene expression include those of KYNU, OAS2, S100A12, and SERPINB3, whose strong transcriptional up-regulation are important discriminators of psoriasis. We observed intrinsic epigenetic differences in uninvolved skin. Pyrosequencing of bisulfite-treated DNA from skin biopsies at three DM loci confirmed earlier findings and revealed a reversion of methylation levels towards the non-psoriatic state after one month of anti-TNF-a therapy.

ORGANISM(S): Homo sapiens

PROVIDER: GSE31835 | GEO | 2011/11/11

SECONDARY ACCESSION(S): PRJNA145123

REPOSITORIES: GEO

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Project description:IL-20 cytokines are involved in the establishment of psoriasis, a common chronic skin inflammation epidemiologically associated with metabolic syndrome, but molecular mechanisms underlying their over-expression remain to be elucidated. We find that keratinocytes (KCs) expressed IL-20 and lymphocytes expressed IL-22 cytokines up-regulation occurs at post-transcriptional level with stabilization of their RNA messengers. Looking at psoriatic epidermis, we observe that the p38/MK2 pathway is not activated but that the RNA-binding protein (RBP) HuR re-localizes in keratinocytes cytoplasm, suggesting post-transcriptional regulation of numerous mRNAs. HuR ribonucleoprotein immunoprecipitations analyzed by high-throughput sequencing (RIP-Seq) identify potential pre-mature and mature RNA targets for uninvolved and involved skin and confirms that HuR activity is displaced from the nucleus to the cytoplasm. Numerous psoriasis up-regulated transcripts are HuR targets and HuR knockdown reduces expression of transcripts like beta-defensin-2, CXCL-10 or IL-2, suggesting an implication of HuR in pathophysiological processes such as morphological, immune and metabolic inflammatory responses. Finally, metabolic disorders affecting psoriatic keratinocytes are responsible for HuR cytoplasmic localization since a decreased activity of the cellular metabolic sensor AMPK, that is observed in human psoriatic epidermis, is sufficient to promote HuR cytosolic localization as well as IL-20 over-production both in human keratinocytes and in vivo in mouse epidermis where it then initiates psoriasis-like histological changes. These results may provide insights into molecular links between metabolism and post-transcriptional networks during chronic inflammation, as illustrated in psoriasis by mechanisms connecting AMPK, HuR and IL-20. Analysis of HuR-binding RNA in uninvolved versus involved psoriatic samples by RIP-Seq. Samples from five different patients were used for both uninvolved and involved skin. RIP-Seq was also made using a control IgG.

Dataset Information

Global methylation analysis of psoriatic (involved and uninvolved) and control skin

Similar Datasets

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