Institute for Diabetes and Cancer (IDC), Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany.
Joint Heidelberg-IDC Translational Diabetes Program, Heidelberg University Hospital, 69120 Heidelberg, Germany.
Int J Mol Sci. 2017 Nov 30;18(12):2578. doi: 10.3390/ijms18122578.
Single cell organisms can surprisingly exceed the number of human protein-coding genes, which are thus not at the origin of the complexity of an organism. In contrast, the relative amount of non-protein-coding sequences increases consistently with organismal complexity. Moreover, the mammalian transcriptome predominantly comprises non-(protein)-coding RNAs (ncRNA), of which the long ncRNAs (lncRNAs) constitute the most abundant part. lncRNAs are highly species- and tissue-specific with very versatile modes of action in accordance with their binding to a large spectrum of molecules and their diverse localization. lncRNAs are transcriptional regulators adding an additional regulatory layer in biological processes and pathophysiological conditions. Here, we review lncRNAs affecting metabolic organs with a focus on the liver, pancreas, skeletal muscle, cardiac muscle, brain, and adipose organ. In addition, we will discuss the impact of lncRNAs on metabolic diseases such as obesity and diabetes. In contrast to the substantial number of lncRNA loci in the human genome, the functionally characterized lncRNAs are just the tip of the iceberg. So far, our knowledge concerning lncRNAs in energy homeostasis is still in its infancy, meaning that the rest of the iceberg is a treasure chest yet to be discovered.
单细胞生物的蛋白编码基因数量惊人地超过了人类，因此，蛋白编码基因并不是生物复杂性的起源。相比之下，非蛋白编码序列的相对含量随着生物体复杂性的增加而持续增加。此外，哺乳动物转录组主要由非（蛋白）编码 RNA（ncRNA）组成，其中长链非编码 RNA（lncRNA）构成了最丰富的部分。lncRNA 具有高度的物种和组织特异性，根据其与大量分子的结合及其多样化的定位，具有非常多样的作用模式。lncRNA 是转录调节剂，在生物过程和病理生理条件下增加了一个额外的调节层。在这里，我们综述了影响代谢器官的 lncRNA，重点是肝脏、胰腺、骨骼肌、心肌、大脑和脂肪组织。此外，我们还将讨论 lncRNA 对肥胖症和糖尿病等代谢疾病的影响。与人类基因组中大量的 lncRNA 基因座相比，功能表征的 lncRNA 只是冰山一角。到目前为止，我们对能量平衡中 lncRNA 的了解还处于起步阶段，这意味着冰山的其余部分是一个有待发现的宝库。
