Urban particulate matters induce EGR-1 expression in keratinocytes which correlates with the severity of psoriasis

Abstract

Background Early growth response protein (Egr)-1 is a transcription factor important for cell growth and initiation of immune responses. It is significantly up-regulated in psoriatic skin. Objective We evaluated the differential expression of Egr-1 in skin lesions of plaque psoriasis and its correlation with the severity of psoriasis. We also used in vitro methods in normal keratinocytes to analyze if urban particulate matter influences Egr-1 expression. Results Egr-1 was significantly up-regulated in the psoriatic skin, specifically in the stratum basale. Its expression was positively correlated with the severity of psoriasis (rho = 0.497, P = 0.013). It was also significantly up-regulated in keratinocytes with exposure to urban particulate matters under in vitro condition. Conclusion Up-regulated expression of Egr-1 in the epidermis suggests that it plays a role in psoriasis by accelerating epidermal cell replication, to which could be attributed by urban particulate matter.