DNA methylation profile of psoriatic skins from different body locations.

Aim: To understand whether the anatomical location of origin plays a role in shaping the DNA methylation (DNAm) landscape of psoriatic skins. Patients & methods: A number of 108 psoriatic and 57 control skin samples were grouped based on their anatomical locations. Two group t-tests were used to identify those differentially methylated sites and regions. Target region methylation loci were validated by bisulfate conversion sequencing. The correlations of DNAm with pathological features, DNAm and gene expression were also interrogated. Results: Our analysis revealed 315 location-specific differentially methylated sites for back, 291 for the extremities and 801 for abdomen. Moreover, we observed that the extremity-specific loci cg21942490 located on HOXA9 is associated with hyperkeratosis. We further observed that HOXA5 and KIAA1949 are differential methylation regions. Conclusion: Our study shown evidence of anatomical location-dependent DNAm pattern in psoriasis skins, and thus provided new insights into the pathogenesis of this disease.