Department of Medicine V, University of Heidelberg, Heidelberg, Germany.
J Cell Physiol. 2011 Sep;226(9):2226-34. doi: 10.1002/jcp.22557.
Long-term culture of human mesenchymal stromal cells (MSC) has implications on their proliferation and differentiation potential and we have demonstrated that this is associated with up-regulation of the five microRNAs miR-29c, miR-369-5p, miR-371, miR-499, and let-7f. In this study, we examined the role of these senescence-associated microRNAs for cellular aging and differentiation of MSC. Proliferation was reduced upon transfection with miR-369-5p, miR-371, and miR-499. Adipogenic differentiation was impaired by miR-369-5p whereas it was highly increased by miR-371. This was accompanied by respective gene expression changes of some adipogenic key molecules (adiponectin and fatty acid-binding protein 4 [FABP4]). Furthermore luciferase reporter assay indicated that FABP4 is a direct target of miR-369-5p. Microarray analysis upon adipogenic or osteogenic differentiation revealed down-regulation of several microRNAs albeit miR-369-5p and miR-371 were not affected. Expression of the de novo DNA methyltransferases DNMT3A and DNMT3B was up-regulated by transfection of miR-371 whereas expression of DNMT3A was down-regulated by miR-369-5p. In summary, we identified miR-369-5p and miR-371 as antagonistic up-stream regulators of adipogenic differentiation and this might be indirectly mediated by epigenetic modifications.
长期培养人类间充质基质细胞（MSC）会影响其增殖和分化潜能，我们已经证明，这与五种 microRNA（miR-29c、miR-369-5p、miR-371、miR-499 和 let-7f）的上调有关。在这项研究中，我们研究了这些与衰老相关的 microRNA 对 MSC 细胞衰老和分化的作用。转染 miR-369-5p、miR-371 和 miR-499 可降低细胞增殖。miR-369-5p 抑制脂肪分化，而 miR-371 则强烈促进脂肪分化。这伴随着一些脂肪生成关键分子（脂联素和脂肪酸结合蛋白 4 [FABP4]）的相应基因表达变化。此外，荧光素酶报告基因测定表明 FABP4 是 miR-369-5p 的直接靶标。在脂肪分化或成骨分化时进行 microarray 分析，发现几个 microRNA 的表达下调，尽管 miR-369-5p 和 miR-371 不受影响。转染 miR-371 可上调从头 DNA 甲基转移酶 DNMT3A 和 DNMT3B 的表达，而 miR-369-5p 可下调 DNMT3A 的表达。总之，我们确定 miR-369-5p 和 miR-371 是脂肪分化的拮抗上游调控因子，这可能是通过表观遗传修饰间接介导的。
