瘦素调节HaCaT细胞角蛋白17的表达

Leptin regulates keratin 17 expression in HaCaT human keratinocytes

目的探讨瘦素对HaCaT细胞角蛋白17（K17）表达的影响。方法体外培养HaCaT细胞，给予100ng／ml的瘦素作用24h，应用实时PCR检On,0K17mRNA表达水平、Western印迹及免疫荧光染色法检测K17蛋白表达水平变化。结果与阴性对照组（1．0000±0．0000）相比较，瘦素组（3．0867±0．1861）K17mRNA表达显著升高，差异有统计学意义（P〈0．01）。Western印迹结果表明，瘦素组K17蛋白较阴性对照组显著上调，细胞免疫荧光染色结果与RT-PCR、Western印迹结果相符。与单纯使用瘦素组（2．2427±0．1887）相比较，STAT3抑制剂组和Erk1／2抑制剂组K17mRNA分别为0．6741±0．0600、0．8550±0．3903，Western印迹和细胞免疫荧光染色显示，两个抑制剂组的K17蛋白较瘦素组均显著下调，差异均有统计学意义（P〈0．01）。结论瘦素可以诱导HaCaT细胞表达K17，其机制可能与激活STAT3、Erk1／2信号转导途径有关。

Objective To evaluate the effect of leptin on K17 expression in HaCaT human keratinocytes. Methods Some cultured HaCaT cells were treated with leptin （100 ng/ml） or remained untreated for 24 hours followed by the quantification of K17 mRNA expression by real-time PCR and detection of K17 protein expression by Western blot and immunofluorescence staining. To investigate the action mechanism of leptin, some cultured HaCaT cells were divided into several groups to be treated with leptin （100 ng/ml） alone, Piceatannol （an inhibitor of the STAT3 pathway） ± leptin （100 ng/ml）, PD-98059 （an inhibitor of the Erkl/2 pathway） ± leptin （100 ng/ml）, respectively for 24 hours, with the cells receiving no treatment as the negative control. Subsequently, the mRNA and protein expressions of K17 were measured by the above methods. Statistical analysis was done by the two-sample t-test. Results The mRNA expression of K17 was significantly higher in HaCaT cells treated with leptin alone than in those remaining untreated （3.086 7± 0.186 1 vs. 1.000 0 ± 0.000 0, P 〈 0.01 ）, but significantly downregulated in HaCaT cells treated with Pieeatannol ± leptin and those with PD-98059 ± leptin compared with those treated leptin alone （0.674 1 ± 0.060 0 and 0.855 0 ± 0.390 3 vs. 2.242 7 ± 0.188 7, both P 〈 0.01）. The results of Western blot and immunofluorescenee staining were in agreement with those of real-time PCR. Conclusions Leptin can induce K17 expression in HaCaT cells, likely by activating the STAT3 and Erk1/2 signaling pathways.