From the Jiangsu Key Laboratory for Molecular and Medical Biotechnology and College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023.
the Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210004.
J Biol Chem. 2018 Mar 16;293(11):4097-4109. doi: 10.1074/jbc.M117.812818. Epub 2018 Jan 23.
Overactivated hepatic gluconeogenesis contributes to the pathogenesis of metabolic disorders, including type 2 diabetes. Precise control of hepatic gluconeogenesis is thus critical for maintaining whole-body metabolic homeostasis. Long non-coding RNAs (lncRNAs) have been shown to play key roles in diseases by regulating diverse biological processes, but the function of lncRNAs in maintaining normal physiology, particularly glucose homeostasis in the liver, remains largely unexplored. We identified a novel liver-enriched long non-coding RNA, Gm10768, and examined its expression patterns under pathophysiological conditions. We further adopted gain- and loss-of-function strategies to explore the effect of Gm10768 on hepatic glucose metabolism and the possible molecular mechanism involved. Our results showed that the expression of Gm10768 was significantly increased in the liver of fasted mice and was induced by gluconeogenic hormonal stimuli. Functionally, overexpression of Gm10768 activated hepatic gluconeogenesis in a cell-autonomous manner. In contrast, depletion of Gm10768 suppressed hepatic glucose production both and Adenovirus-mediated hepatic knockdown of Gm10768 improved glucose tolerance and hyperglycemia of diabetic mice. Mechanistically, Gm10768 sequestrated microRNA-214 (miR-214) to relieve its suppression on activating transcription factor 4 (ATF4), a positive regulator of hepatic gluconeogenesis. Taken together, we identified Gm10768 as a new lncRNA activating hepatic gluconeogenesis through antagonizing miR-214 in mice.
过度激活的肝糖异生导致代谢紊乱的发生,包括 2 型糖尿病。因此,精确控制肝糖异生对于维持全身代谢平衡至关重要。长链非编码 RNA(lncRNA)已被证明通过调节多种生物过程在疾病中发挥关键作用,但 lncRNA 在维持正常生理机能(尤其是肝脏中的葡萄糖稳态)方面的功能仍在很大程度上未被探索。我们鉴定了一种新型的肝脏丰富的长链非编码 RNA,Gm10768,并研究了其在病理生理条件下的表达模式。我们进一步采用了增益和损耗功能策略来探索 Gm10768 对肝葡萄糖代谢的影响及其可能涉及的分子机制。我们的结果表明,Gm10768 的表达在禁食小鼠的肝脏中显著增加,并受到糖异生激素刺激的诱导。功能上,Gm10768 的过表达以细胞自主的方式激活肝糖异生。相比之下,Gm10768 的耗竭抑制了肝葡萄糖的产生。腺相关病毒介导的肝脏 Gm10768 敲低可改善糖尿病小鼠的葡萄糖耐量和高血糖。机制上,Gm10768 可将 microRNA-214(miR-214)隔离,从而解除其对激活转录因子 4(ATF4)的抑制作用,ATF4 是肝糖异生的正调控因子。总之,我们鉴定了 Gm10768,它通过在小鼠中拮抗 miR-214 来激活肝糖异生。