Abstract：
Accumulating evidence indicates that microRNAs (miRNAs) have a vital effect on the pathogenesis of psoriasis. This study is conducted to investigate the potential involvement of miR-181a-5p and miR-181b-5p in the proliferation of HaCaT keratinocytes. Cell viability and proliferation were evaluated respectively in this study using the CCK-8 and the 5-ethynyl-2\'-deoxyuridine (EdU) assays. The expression of Maternal Embryonic Leucine Zipper Kinase (MELK) and Keratin 16 (KRT16) mRNA and protein in tissues and cells was assessed using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. The Luciferase reporter system analyzes the connection between miR-181a-5p/miR-181b-5p and MELK. The results showed that miR-181a/b-5p expression was downregulated in the psoriasis lesions and negatively regulated the proliferation of keratinocytes. MELK was directly targeted by miR-181a-5p/miR-181b-5p. In addition, HaCaT keratinocytes proliferation was inhibited by knockdown of MELK while promoted dramatically by MELK overexpression. Notably, miR-181a/b-5p mimics could attenuate the effects of MELK in keratinocytes. In conclusion, our research findings suggested miR-181a-5p and miR-181b-5p negatively regulate keratinocyte proliferation by targeting MELK, providing potential diagnostic biomarkers and therapeutic targets for psoriasis.
摘要：
越来越多的证据表明，microRNAs（miRNAs）在银屑病的发病机制中具有重要作用。进行这项研究以研究miR-181a-5p和miR-181b-5p在HaCaT角质形成细胞增殖中的潜在参与。在本研究中使用CCK-8和5-乙炔基-2'-脱氧尿苷(EdU)测定分别评估细胞活力和增殖。使用定量实时聚合酶链反应（qRT-PCR）和Western印迹评估组织和细胞中母体胚胎亮氨酸拉链激酶（MELK）和角蛋白16（KRT16）mRNA和蛋白的表达。荧光素酶报告系统分析miR-181a-5p/miR-181b-5p与MELK之间的联系。结果显示miR-181a/b-5p在银屑病皮损中表达下调,对角质形成细胞的增殖产生负调控作用。MELK被miR-181a-5p/miR-181b-5p直接靶向。此外,HaCaT角质形成细胞增殖被MELK的敲低抑制,同时被MELK过表达显著促进。值得注意的是,miR-181a/b-5p模拟物可以减弱MELK在角质形成细胞中的作用。总之,我们的研究结果表明，miR-181a-5p和miR-181b-5p通过靶向MELK负调控角质形成细胞增殖，为银屑病提供潜在的诊断生物标志物和治疗靶点。
