Mechanisms underlying interleukin-22-induced expression of heparin-binding epidermal growth factor-like growth factor in HaCaT cells / 中华皮肤科杂志

ABSTRACT

Objective To investigate the mechanisms underlying intedeukin-22 (IL-22)-induced expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in HaCaT cells.Methods Some HaCaT cells were divided into several inverention groups treated with IL-22 at concentrations of 12.5,25,50,100 μg/L,respectively and a control group treated with phosphate buffer saline (PBS).After 24-hour culture,total proteins were extracted from the HaCaT cells,and Western blot was performed to measure the expression of phosphorylated extracellular signalregulated kinase 1/2 (P-ERK1/2) in the mitogen-activated protein kinase (MAPK)-ERK1/2 pathway,as well as phosphorylated-JAK2 (P-JAK2) and phosphorylated-signal transducer and activator of transcription 3 (P-STAT3) in the JAK2/STAT3 pathway.In a blocking experiment,some HaCaT cells were divided into 4 groups to be treated with PBS,IL-22,PD98059 (an inhibitor of MAPK-ERK1/2) combined with IL-22 (PD98059 group),AG490 (an inhibitor of JAK2/STAT3) combined with IL-22 (AG490 group),respectively.After 24-hour treatment,total proteins and mRNAs were extracted from the HaCaT cells followed by Western blot and real-time quantitative reverse transcription-PCR for the measurement of protein and mRNA expressions of HB-EGF respectively.Statistical analysis was carried out with the software SPSS 16.0 by one-way analysis of variance (ANOVA) for intergroup comparisons and by Bonferroni's test for multiple comparisons.Results After treatment with IL-22 at the above 4 concentrations,the expressions of P-ERK1/2,P-JAK2 and P-STAT3 in HaCaT cells were all increased compared with the control group (all P ＜ 0.05).The protein and mRNA expression levels (expressed as the HB-EGF/β-actin ratio and 2-△△Cr respectively) of HB-EGF were both significantly decreased in the PD98059 group and AG490 group than in the IL-22 group (protein:0.183 ± 0.020 and 0.199 ± 0.011 vs.0.924 ± 0.032,F =37.700,36.400,respectively,both P ＜ 0.05; mRNA:1.034 ± 0.072 and 0.989 ± 0.038 vs.1.844 ± 0.135,F =11.271,13.429,respectively,both P ＜ 0.05).Conclusions IL-22 can activate the MAPK-ERK1/2 and JAK2/STAT3 signaling pathways in HaCaT cells,which may contribute to IL-22-induced expression of HB-EGF in HaCaT cells.