Effects of tacrolimus on the secretion of chemokines CXCL9 and CXCL10 by γ-interferon-simulated HaCaT cells / 中华皮肤科杂志

ABSTRACT

Objective To analyze effects of tacrolimus on the secretion of chemokines CXCL9 and CXCL10 by γ-interferon (IFN-γ)-simulated HaCaT cells,as well as phosphorylated Janus kinase 1 (p-JAK1) and phosphorylated signal transducer and activator of transcription 1 (p-STAT1),and to explore the mechanism of tacrolimus in the treatment of vitiligo.Methods HaCaT cells were treated with l,10,20,40,60,80,100,120 mg/L tacrolimus solution separately for 4 hours,and methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate the cellular proliferative activity.HaCaT cells were divided into 4 groupsblank control group receiving no treatment,IFN-γgroup treated with 500 U/ml IFN-γfor 12 or 48 hours,tacrolimus group treated with 20 mg/L tacrolimus for 4 hours,and tacrolimus + IFN-γgroup treated with 20 mg/L tacrolimus for 4 hours followed by the treatment with 500 U/ml IFN-γfor 12 or 48 hours.Real-time fluorescence-based quantitative PCR was conducted to measure the mRNA expression of CXCL9 and CXCL10,Western blot analysis to determine the protein expression of CXCL9,CXCL10,p-JAK1,and p-STAT1,and enzyme-linked immunosorbent assay (ELISA) to detect the levels of CXCL9 and CXCL10 in the culture supernatants of HaCaT cells.Results Tacrolimus at the maximum concentration of 20 mg/L had no effect on the proliferation of HaCaT cells (P ＞ 0.05).After the pretreatment with 20 mg/L tacrolimus,the mRNA expression of CXCL9 and CXCL10 significantly decreased from 10 369.08 ± 7.99 and 290.02 ± 2.16 to 5 914.33 ± 4.59 and 114.96 ± 0.73,respectively,after the treatment with IFN-γ(both P ＜ 0.01),and the protein expression of CXCL9,CXCL10,p-JAK1,and p-STAT1 also significantly decreased from 8.47 ± 0.29,7.87 ± 0.17,4.20 ± 0.18 and 4.29 ± 0.11 to 7.36 ± 0.13,7.36 ± 0.09,2.60 ± 0.16 and 3.62 ± 0.19,respectively,after the treatment with IFN-γ (all P ＜ 0.01).Moreover,the levels of CXCL9 and CXCL10 in the culture supernatants of HaCaT cells significantly decreased in the IFN-γgroup (1 213.36 ± 0.95,1 722.41 ± 2.57,respectively) compared with the tacrolimus + IFN-γ group (426.45 ± 0.31,554.12 ± 0.56,respectively,both P ＜ 0.01).Conclusion Tacrolimus can inhibit the secretion of CXCL9,CXCL10,p-JAK1 and p-STAT1 by HaCaT cells stimulated by IFN-γ.