Abnormal histone modifications in PBMCs from patients with psoriasis vulgaris.

Excessive keratinocyte proliferation is thought to be responsible for the formation and development of psoriasis vulgaris. Evidence indicates that epigenetic modifications are associated with aberrant gene expression, however, nothing is known about the status of histone modifications in psoriasis vulgaris. We investigated alterations in histone modifications in patients with psoriasis vulgaris. Global histone H3/H4 acetylation and H3K4/H3K27 methylation in peripheral blood mononuclear cells from 30 psoriatic patients and 20 healthy control subjects were quantified by the EpiQuik(TM) global histone H3/H4 acetylation and H3K4/H3K27 methylation assay kit. The mRNA levels of 12 members of 3 classes of chromatin modifier genes were measured by real-time quantitative polymerase chain reaction. Compared with normal controls, global histone H4 hypoacetylation was observed in PBMCs from psoriasis vulgaris patients. There was a negative correlation between the degree of histone H4 acetylation and disease activity in patients as measured by PASI. Global levels of H3 acetylation, H3K4/H3K27 methylation did not significantly differ between psoriatic patients and controls. mRNA levels of P300, CBP and SIRT1 were significantly reduced in PBMCs from patients with psoriasis vulgaris compared with healthy controls, while mRNA expression levels of HDAC1, SUV39H1 and EZH2 was significantly increased in psoriatic patients.We conclude that histone modifications are aberrant in the PBMCs of psoriasis vulgaris patients.