Objective: To investigate the mechanisms of interleukin-17A (IL-17A) regulating the expressions of IL-1β and IL-23 in mouse keratinocytes (KCs). Methods: Primary KCs were isolated from the skin of 400 newborn male and female wild type C57BL/6 mice and cultured in 24-well plates with Roswell Park Memorial Institute 1640 medium containing fetal bovine serum in the volume fraction of 10% for the following experiments. (1) The cells were divided into phosphate buffer solution (PBS) control group and IL-17A stimulation group according to the random number table (the same grouping method below), which were cultured with 10 μL PBS or 10 μL IL-17A in the mass concentration of 100 ng/mL for 6 hours, respectively. The expression levels of IL-1β and IL-23 mRNA in cells were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR), with 3 samples in each group. (2) The cells were divided into dimethyl sulfoxide (DMSO) control group, IL-17A+ DMSO group, IL-17A+ nuclear factor κB (NF-κB) inhibitor group, IL-17A+ signal transduction and activator of transcription 3 (STAT3) inhibitor group, IL-17A+ extracellular signal-regulated kinase 1 (ERK1) inhibitor group, IL-17A+ ERK2 inhibitor group, and IL-17A+ c-Jun N-terminal kinase (JNK) inhibitor group. The reagents were added to cells in corresponding groups respectively and cultured for 6 hours. The volume of each reagent was 10 μL, the mass concentration of IL-17A was 100 ng/mL, and the molarity concentrations of NF-κB, STAT3, ERK1, ERK2, JNK signal pathway inhibitors PDTC, S3I-201, SCH772984, SCH772984, SP600125 were 5 μmol/L, 100 μmol/L, 4 nmol/L, 1 nmol/L, and 10 μmol/L, respectively. The expression levels of IL-1β mRNA and IL-23 mRNA in cells were detected by real-time fluorescence quantitative RT-PCR, with 3 samples in each group. (3) The cells were grouped and treated the same as those in experiment (1). The levels of NF-κB phosphorylation, STAT3 phosphorylation, ERK phosphorylation, and JNK phosphorylation were detected by Western blotting, with 3 samples in each group. Data were statistically analyzed with two-tailed Student t test, one-way analysis of variance, t test, and Bonferroni correction. Results: (1) After culture of 6 hours, compared with those in PBS control group, the expression levels of IL-1β and IL-23 mRNA in cells in IL-17A stimulation group were significantly increased (t=13.46, 6.72, P<0.01). (2) After culture of 6 hours, the expression levels of IL-1β and IL-23 mRNA in cells in DMSO control group, IL-17A+ DMSO group, IL-17A+ NF-κB inhibitor group, IL-17A+ STAT3 inhibitor group, IL-17A+ ERK1 inhibitor group, IL-17A+ ERK2 inhibitor group, and IL-17A+ JNK inhibitor group were 1.00±0.11, 4.01±0.32, 0.32±0.06, 1.76±0.43, 3.62±0.24, 3.80±0.43, 4.26±0.74 and 1.03±0.29, 4.08±0.34, 4.76±0.38, 4.70±0.21, 1.06±0.42, 0.92±0.21, 0.39±0.05, respectively. Compared with those in DMSO control group, the expression levels of IL-1β and IL-23 mRNA in cells in IL-17A+ DMSO group were significantly increased (t=9.24, 12.60, P<0.01). Compared with that in IL-17A+ DMSO group, the expression level of IL-1β mRNA was significantly decreased in cells in IL-17A+ NF-κB inhibitor group and IL-17A+ STAT3 inhibitor group (t=11.34, 6.91, P<0.01). Compared with that in IL-17A+ DMSO group, the expression level of IL-23 mRNA was significantly decreased in cells in IL-17A+ ERK1 inhibitor group, IL-17A+ ERK2 inhibitor group, and IL-17A+ JNK inhibitor group (t=12.44, 13.03, 15.21, P<0.01). (3) After culture of 6 hours, compared with those in PBS control group, the levels of NF-κB phosphorylation, STAT3 phosphorylation, ERK phosphorylation, and JNK phosphorylation in cells in IL-17A stimulation group were significantly increased. Conclusions: IL-17A promotes the transcription of IL-1β in mouse KCs through the phosphorylation of NF-κB and STAT3 pathways and IL-23 through the phosphorylation of ERK and JNK pathways.
目的： 探讨白细胞介素17A(IL-17A)调控小鼠角质形成细胞(KC)表达IL-1β和IL-23的机制。 方法： 从400只新生雌雄不限C57BL/6野生型小鼠皮肤中分离原代KC，用含体积分数10%胎牛血清的RPMI 1640培养基培养于24孔板中，用于以下实验。(1)取细胞，采用随机数字表法(分组方法下同)分为磷酸盐缓冲液(PBS)对照组、IL-17A刺激组，分别加入10 μL的PBS、质量浓度为100 ng/mL的IL-17A培养6 h，采用实时荧光定量反转录PCR法检测细胞中IL-1β和IL-23 mRNA表达水平，每组3个样本。(2)取细胞，分为二甲基亚砜(DMSO)对照组、IL-17A＋DMSO组、IL-17A＋核因子κB抑制剂组、IL-17A＋信号转导及转录激活因子3(STAT3)抑制剂组、IL-17A＋胞外信号调节激酶1(ERK1)抑制剂组、IL-17A＋ERK2抑制剂组、IL-17A＋c-Jun氨基端激酶(JNK)抑制剂组，分别加入相应试剂，各试剂体积均为10 μL，IL-17A质量浓度为100 ng/mL，核因子κB、STAT3、ERK1、ERK2、JNK信号通路抑制剂PDTC、S3I-201、SCH772984、SCH772984、SP600125物质的量浓度分别为5 μmol/L、100 μmol/L、4 nmol/L、1 nmol/L、10 μmol/L，均培养6 h。采用实时荧光定量反转录PCR法检测细胞中IL-1β和IL-23 mRNA表达水平，每组3个样本。(3)取细胞，同实验(1)分组处理，采用蛋白质印迹法检测细胞中核因子κB磷酸化、STAT3磷酸化、ERK磷酸化、JNK磷酸化水平，每组3个样本。对数据行双尾Student t检验、单因素方差分析、t检验和Bonferroni校正。 结果： (1)培养6 h，与PBS对照组比较，IL-17A刺激组细胞中IL-1β和IL-23 mRNA表达水平均明显升高(t＝13.46、6.72，P<0.01)。(2)培养6 h，DMSO对照组、IL-17A＋DMSO组、IL-17A＋核因子κB抑制剂组、IL-17A＋STAT3抑制剂组、IL-17A＋ERK1抑制剂组、IL-17A＋ERK2抑制剂组、IL-17A＋JNK抑制剂组细胞中IL-1β与IL-23 mRNA表达水平分别为1.00±0.11、4.01±0.32、0.32±0.06、1.76±0.43、3.62±0.24、3.80±0.43、4.26±0.74和1.03±0.29、4.08±0.34、4.76±0.38、4.70±0.21、1.06±0.42、0.92±0.21、0.39±0.05。与DMSO对照组比较，IL-17A＋DMSO组细胞中IL-1β和IL-23 mRNA表达水平均明显升高(t＝9.24、12.60，P<0.01)。与IL-17A＋DMSO组比较，IL-17A＋核因子κB抑制剂组与IL-17A＋STAT3抑制剂组细胞中IL-1β mRNA表达水平均明显下降(t＝11.34、6.91，P<0.01)，IL-17A＋ERK1抑制剂组、IL-17A＋ERK2抑制剂组和IL-17A＋JNK抑制剂组细胞中IL-23 mRNA表达水平均明显下降(t＝12.44、13.03、15.21，P<0.01)。(3)培养6 h，与PBS对照组比较，IL-17A刺激组细胞中核因子κB磷酸化、STAT3磷酸化、ERK磷酸化、JNK磷酸化水平均明显升高。 结论： IL-17A分别通过促进核因子κB、STAT3信号通路磷酸化与ERK、JNK信号通路磷酸化促进小鼠KC转录表达IL-1β与IL-23。.
Keywords: Extracellular signal-regulated kinase; Interleukin-17A; Interleukin-1beta; Interleukin-23; Keratinocytes; NF-kappa B; Signal transduction and activator of transcription 3; c-Jun N-terminal kinase.