It was reported that microRNA-21(miR-21) was differentially expressed in the keratinocytes of psoriasis patients, and it may influence the apoptosis and proliferation of cells. The role of lncRNA maternally expressed gene3 (MEG3), a competing endogenous RNAs of miR-21, in the progression of psoriasis remains unclear. We aimed to unfold the influence of MEG3 and miR-21 on the proliferation and apoptosis of psoriasis epidermal cells. 50μg/L TNF-α was used to treat HaCaTs and NHEKs cells for 24 h, and then different experiments were conducted. qRT-PCR were applied for measuring the mRNA level of MEG3, miR-2, and caspase-8, and the protein expression of caspase-8 was measured with western blotting. Flow cytometry was used for assessing apoptosis. Cell proliferation was detected using MTT and colony formation assays. Dual luciferase reporter assay was applied for confirming the binding site between MEG3 and miR-21, miR-21 and Caspase-8. A cell model for in vitro studying the role of MEG3 in psoriasis pathophysiology was established using HaCaT and HHEKs. MEG3 was significantly down-regulated in HaCaT, HHEKs, and psoriatic skin samples. MEG3 inhibits proliferation and promotes apoptosis of Activated-HaCaT (Act-HaCaT) and Activated-HHEKs (Act- HHEK) by regulating miR-21, and the binding site between MEG3 and miR-21 was identified. We also found that miR-21 could inhibit the level of caspase-8 and identified the binding site between caspase-8 and miR-21. Some down-stream proteins of caspase-8, Cleaved caspase-8, cytc, and apaf-1 were regulated by miR-21 and MEG3. MEG3/miR-21 axis may regulate the expression of caspase-8, and further influence the proliferation and apoptosis of psoriasis keratinocyte, Act-HaCaT and Act- HHEK. Therefore, our findings may provide a new thought for the study of pathogenesis and treatment of psoriasis.

中文翻译：

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LncRNA MEG3通过靶向miR-21 / caspase-8影响牛皮癣表皮细胞的增殖和凋亡

据报道，microRNA-21（miR-21）在牛皮癣患者的角质形成细胞中差异表达，可能影响细胞的凋亡和增殖。lncRNA母本表达的基因3（MEG3）（一种与miR-21竞争的内源性RNA）在银屑病进展中的作用尚不清楚。我们旨在揭示MEG3和miR-21对牛皮癣表皮细胞增殖和凋亡的影响。用50μg/ L的TNF-α处理HaCaTs和NHEKs细胞24小时，然后进行不同的实验。采用qRT-PCR检测MEG3，miR-2和caspase-8的mRNA水平，并用western blotting检测caspase-8的蛋白表达。流式细胞仪用于评估细胞凋亡。使用MTT和集落形成测定法检测细胞增殖。应用双重荧光素酶报告基因测定法确认MEG3与miR-21，miR-21和Caspase-8之间的结合位点。使用HaCaT和HHEKs建立了用于体外研究MEG3在牛皮癣病理生理中的作用的细胞模型。在HaCaT，HHEK和牛皮癣皮肤样本中，MEG3显着下调。MEG3通过调节miR-21抑制增殖并促进活化的HaCaT（Act-HaCaT）和活化的HHEKs（Act-HHEK）的凋亡，并鉴定了MEG3与miR-21之间的结合位点。我们还发现miR-21可以抑制caspase-8的水平，并确定了caspase-8和miR-21之间的结合位点。miR-21和MEG3调控caspase-8，Cleaved caspase-8，cytc和apaf-1的某些下游蛋白。MEG3 / miR-21轴可能调节caspase-8的表达，并进一步影响银屑病角质形成细胞，Act-HaCaT和Act-HHEK的增殖和凋亡。因此，我们的发现可能为牛皮癣的发病机理和治疗研究提供新的思路。