Hu Xiao-Ping, Xie Qian, Chen Chao-Feng, Zhang Wei, Yu Bo
Department of Dermatology, Peking University Shenzhen Hospital, Shenzhen, China.
Department of endocrinology, Peking University Shenzhen Hospital, Shenzhen, China.
Cell Physiol Biochem. 2017;42(1):115-125. doi: 10.1159/000477120. Epub 2017 May 12.
This study aimed to explore the effects of STAT3 targeting by let-7a on T-cell proliferation and IFN-γ secretion in psoriasis.
From January 2013 to January 2015, 40 patients with psoriasis (psoriasis group) and 38 volunteers undergoing plastic surgery (control group) were enrolled in this study. Pearson correlation analysis was performed to evaluate the correlation between let-7a and STAT3 expression. T-cells were isolated and subjected to different transfection methods. A dual luciferase reporter assay was carried out to confirm STAT3 as a target gene of let-7a. Let-7a, STAT3 and IFN-γ mRNA expression was detected by quantitative real-time fluorescent polymerase chain reaction (qRT-PCR), and pSTAT3 protein levels were determined by Western blot. T-cell proliferation was evaluated with a cell counting kit-8 (CCK-8) assay.
The level of STAT3 mRNA and pSTAT3 was higher, but let-7a expression was lower in the psoriasis group than the control group. Pearson correlation analysis indicated that STAT3 expression was negatively correlated with let-7a expression. T-cells transfected with inhibitors exhibited greater IFN-γ mRNA expression and T-cell proliferation than transfected T-cells and T-cells transfected with a non-sense sequence, while T-cells transfected with let-7a mimics exhibited lower IFN-γ mRNA expression and T-cell proliferation than transfected T-cells and T-cells transfected with a non-sense sequence. This suggested that siRNA-STAT3 could reverse the increase in IFN-y mRNA expression and T-cell proliferation induced by let-7a inhibitors.
Our results demonstrated that let-7a inhibits T-cell proliferation and IFN-γ secretion by down-regulating STAT3 in psoriasis.
本研究旨在探讨let-7a靶向信号转导和转录激活因子3（STAT3）对银屑病中T细胞增殖及γ干扰素（IFN-γ）分泌的影响。
2013年1月至2015年1月，本研究纳入40例银屑病患者（银屑病组）和38例接受整形手术的志愿者（对照组）。采用Pearson相关分析评估let-7a与STAT3表达之间的相关性。分离T细胞并采用不同的转染方法。进行双荧光素酶报告基因检测以证实STAT3是let-7a的靶基因。采用定量实时荧光聚合酶链反应（qRT-PCR）检测let-7a、STAT3和IFN-γ mRNA表达水平，采用蛋白质免疫印迹法测定磷酸化STAT3（pSTAT3）蛋白水平。采用细胞计数试剂盒-8（CCK-8）检测评估T细胞增殖情况。
银屑病组STAT3 mRNA和pSTAT3水平高于对照组，但let-7a表达低于对照组。Pearson相关分析表明，STAT3表达与let-7a表达呈负相关。与转染T细胞及转染无义序列的T细胞相比，转染抑制剂的T细胞表现出更高的IFN-γ mRNA表达和T细胞增殖，而与转染T细胞及转染无义序列的T细胞相比，转染let-7a模拟物的T细胞表现出更低的IFN-γ mRNA表达和T细胞增殖。这表明小干扰RNA-STAT3（siRNA-STAT3）可逆转let-7a抑制剂诱导的IFN-γ mRNA表达增加和T细胞增殖。
我们的结果表明，在银屑病中，let-7a通过下调STAT3抑制T细胞增殖和IFN-γ分泌。
