TY - JOUR AB - Psoriasis vulgaris is a common chronic inflammatory skin disease characterized by the hyperproliferation and abnormal differentiation of keratinocytes. CCATT/enhancer binding protein α (C/EBPα) is abundant in the epidermis and is associated with the proliferation of keratinocytes. However, the role of C/EBPα in the proliferation of keratinocytes and the pathogenesis of psoriasis vulgaris are yet to be elucidated. In the present study, using two-step immunohistochemistry, the expression levels of C/EBPα and Ki‑67 were examined in skin biopsies harvested from 30 patients with psoriasis vulgaris and 30 healthy control subjects. The proliferation index (PI) was calculated and the correlation between C/EBPα expression levels and the PI was assessed using Pearson's correlation coefficient. In addition, the effect on HaCaT immortalized human keratinocytic cells of treatment with various concentrations of interleukin (IL)-17 was investigated. Subsequently, cell proliferation rates were examined using a Cell Counting kit‑8 assay and the mRNA and protein expression levels of C/EBPα were analyzed using semiquantitative reverse transcription-polymerase chain reaction and western blotting, respectively, in order to analyze the effects of IL‑17 stimulation on C/EBPα expression levels. C/EBPα expression was predominantly detected in the cytoplasm of the keratinocytes and C/EBPα expression levels were significantly lower in the psoriatic lesions (P<0.05), as compared with the control group. An inverse correlation was detected between the expression levels of C/EBPα and the PI in the psoriatic lesions. Furthermore, a significant increase in the cell proliferation rate and significant reductions in the mRNA and protein expression levels of C/EBPα were detected in HaCaT cells following treatment with IL‑17. These results demonstrated that C/EBPα may act as a downstream target of IL‑17 and may be associated with the pathogenesis of psoriasis. AD - Department of Dermatology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, P.R.China School of Medicine, Shandong University, Jinan, Shandong 250012, P.R.China AU - Ma,Wei‑Yuan AU - Jia,Kun AU - Zhang,Yan DA - 2016/02/01 DO - 10.3892/etm.2015.2939 EP - 636 IS - 2 JO - Exp Ther Med KW - psoriasis vulgaris keratinocyte proliferation CCATT/enhancer binding protein α interleukin-17 PY - 2016 SN - 1792-0981 1792-1015 SP - 631 ST - IL-17 promotes keratinocyte proliferation via the downregulation of C/EBPα T2 - Experimental and Therapeutic Medicine TI - IL-17 promotes keratinocyte proliferation via the downregulation of C/EBPα UR - https://doi.org/10.3892/etm.2015.2939 VL - 11 ER -