Department of Experimental Pathology, Instituto de Investigaciones Biomédicas de Barcelona, Spanish Research Council (IIBB-CSIC, IDIBAPS), Barcelona, Spain.
1] Department of Experimental Pathology, Instituto de Investigaciones Biomédicas de Barcelona, Spanish Research Council (IIBB-CSIC, IDIBAPS), Barcelona, Spain [2] CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Department of Experimental Pathology, IIBB-CSIC-IDIBAPS, Barcelona, Spain.
Cell Death Dis. 2014 Feb 6;5(2):e1048. doi: 10.1038/cddis.2014.2.
miRNA let-7e is involved in stem cell differentiation, and metalloproteinases are among its potential target genes. We hypothesized that the inhibitory action of let-7e on regulation of MMP9 expression could represent a crucial mechanism during differentiation of adipose-derived stem cells (ASCs). ASCs were differentiated with all-trans retinoic acid (ATRA) to promote differentiation, and the effect of let-7 silencing during differentiation was tested. Results indicate that ASCs cultured with ATRA differentiated into cells of the epithelial lineage. We found that ASCs cultured with ATRA or transfected with miRNA let-7e expressed epithelial markers such as cytokeratin-18 and early renal organogenesis markers such as Pax2, Wt1, Wnt4 and megalin. Conversely, the specific knockdown of miRNA let-7e in ASCs significantly decreased the expression of these genes, indicating its vital role during the differentiation process. Using luciferase reporter assays, we also showed that MMP9 is a direct target of miRNA let-7e. Thus, our results suggest that miRNA let-7e acts as a matrix metalloproteinase-9 (MMP9) inhibitor and differentiation inducer in ASCs.
miRNA let-7e 参与干细胞分化，金属蛋白酶是其潜在的靶基因之一。我们假设 let-7e 对 MMP9 表达的抑制作用可能代表脂肪来源干细胞 (ASCs) 分化过程中的一个关键机制。用全反式视黄酸 (ATRA) 将 ASCs 分化以促进分化，并测试 let-7 沉默在分化过程中的作用。结果表明，用 ATRA 培养的 ASCs 分化为上皮谱系的细胞。我们发现，用 ATRA 培养或转染 miRNA let-7e 的 ASCs 表达上皮标志物，如细胞角蛋白-18 和早期肾发生标志物，如 Pax2、Wt1、Wnt4 和 megalin。相反，miRNA let-7e 在 ASCs 中的特异性敲低显著降低了这些基因的表达，表明其在分化过程中的重要作用。通过荧光素酶报告基因检测，我们还表明 MMP9 是 miRNA let-7e 的直接靶基因。因此，我们的结果表明 miRNA let-7e 在 ASCs 中作为基质金属蛋白酶-9 (MMP9) 抑制剂和分化诱导剂发挥作用。
