Walden Tomas B, Timmons James A, Keller Pernille, Nedergaard Jan, Cannon Barbara
The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden.
J Cell Physiol. 2009 Feb;218(2):444-9. doi: 10.1002/jcp.21621.
MicroRNAs, a novel class of post-transcriptional gene regulators, have been demonstrated to be involved in several cellular processes regulating the expression of protein-coding genes. Here we examine murine white and brown primary cell cultures for differential expression of miRNAs. The adipogenesis-related miRNA miR-143 was highly expressed in mature white adipocytes but was low in mature brown adipocytes. Three classical "myogenic" miRNAs miR-1, miR-133a and miR-206 were absent from white adipocytes but were specifically expressed both in brown pre- and mature adipocytes, reinforcing the concept that brown adipocytes and myocytes derive from a common cell lineage that specifies energy-dissipating cells. Augmentation of adipocyte differentiation status with norepinephrine or rosiglitazone did not affect the expression of the above miRNAs, the expression levels of which were thus innately regulated. However, expression of the miRNA miR-455 was enhanced during brown adipocyte differentiation, similarly to the expression pattern of the brown adipocyte differentiation marker UCP1. In conclusion, miRNAs are differentially expressed in white and brown adipocytes and may be important in defining the common precursor cell for myocytes and brown adipocytes and thus have distinct roles in energy-storing versus energy-dissipating cells.
微小RNA是一类新型的转录后基因调节因子，已被证明参与多种调节蛋白质编码基因表达的细胞过程。在此，我们检测了小鼠白色和棕色原代细胞培养物中微小RNA的差异表达。与脂肪生成相关的微小RNA miR-143在成熟白色脂肪细胞中高表达，但在成熟棕色脂肪细胞中低表达。三种经典的“成肌”微小RNA miR-1、miR-133a和miR-206在白色脂肪细胞中不存在，但在棕色前脂肪细胞和成熟脂肪细胞中均特异性表达，这强化了棕色脂肪细胞和肌细胞源自指定能量消耗细胞的共同细胞谱系的概念。用去甲肾上腺素或罗格列酮增强脂肪细胞分化状态并不影响上述微小RNA的表达，因此其表达水平是固有调节的。然而，微小RNA miR-455的表达在棕色脂肪细胞分化过程中增强，类似于棕色脂肪细胞分化标志物解偶联蛋白1的表达模式。总之，微小RNA在白色和棕色脂肪细胞中差异表达，可能在定义肌细胞和棕色脂肪细胞的共同前体细胞方面很重要，因此在能量储存细胞与能量消耗细胞中具有不同作用。
