Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Campus Kiel, Brunswiker Str. 10, 24105 Kiel, Germany.
J Steroid Biochem Mol Biol. 2013 Jan;133:129-39. doi: 10.1016/j.jsbmb.2012.09.005. Epub 2012 Sep 24.
11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1, gene HSD11B1) converts glucocorticoid receptor-inert cortisone to receptor-active cortisol. Multiple evidence supports a causal role for 11β-HSD1 in the current obesity epidemic. In obese, HSD11B1 expression is increased in adipose tissue but typically decreased in liver, and the underlying tissue-specific mechanisms are largely unknown. In this context, we investigated a potential role of microRNAs (miRNAs). We used several miRNA target prediction tools to identify possible candidates and a publicly available miRNA expression atlas to further select candidates expressed in hepatocytes. Using a dual luciferase reporter assay, we identified three potential miRNAs, hsa-miR-340, -561 and -579, as potential negative regulators of HSD11B1 expression. Disruption of the corresponding microRNA response elements abolished repression of luciferase activity for hsa-miR-561 and -579, but not for hsa-miR-340. Furthermore, levels of firefly luciferase mRNA were not changed by miR-561 and -579, indicating a mechanism based on translational repression rather than mRNA degradation. Finally, we were able to detect both, miR-561 and -579, in human total liver RNA by reverse-transcription-polymerase chain reaction (RT-PCR). According to the presented results, miR-561 and -579 are likely to be involved in the tissue-specific regulation of HSD11B1 expression. Moreover, literature findings and a pathway enrichment analysis support a potential role of these two miRNAs in glucocorticoid metabolism and signalling and associated diseases.
11β-羟类固醇脱氢酶 1 型（11β-HSD1，基因 HSD11B1）将糖皮质激素受体无活性的可的松转化为受体活性的皮质醇。大量证据支持 11β-HSD1 在当前肥胖流行中的因果作用。在肥胖中，脂肪组织中 HSD11B1 的表达增加，但肝脏中的表达通常降低，其潜在的组织特异性机制在很大程度上尚不清楚。在这种情况下，我们研究了 microRNAs（miRNAs）的潜在作用。我们使用了几种 miRNA 靶标预测工具来识别可能的候选物，并使用公共 miRNA 表达图谱进一步选择在肝细胞中表达的候选物。使用双荧光素酶报告基因检测，我们鉴定了三个潜在的 miRNA，hsa-miR-340、-561 和 -579，作为 HSD11B1 表达的潜在负调控因子。破坏相应的 microRNA 反应元件消除了 hsa-miR-561 和 -579 对荧光素酶活性的抑制作用，但对 hsa-miR-340 没有作用。此外，miR-561 和 -579 并未改变萤火虫荧光素酶 mRNA 的水平，表明其机制基于翻译抑制而不是 mRNA 降解。最后，我们能够通过逆转录-聚合酶链反应（RT-PCR）检测到人类总肝 RNA 中的 miR-561 和 -579。根据所呈现的结果，miR-561 和 -579 可能参与 HSD11B1 表达的组织特异性调节。此外，文献发现和途径富集分析支持这两种 miRNA 在糖皮质激素代谢和信号转导及相关疾病中的潜在作用。
