Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
Proc Natl Acad Sci U S A. 2012 Sep 4;109(36):14568-73. doi: 10.1073/pnas.1211611109. Epub 2012 Aug 16.
The effects of adiponectin on hepatic glucose and lipid metabolism at transcriptional level are largely unknown. We profiled hepatic gene expression in adiponectin knockout (KO) and wild-type (WT) mice by RNA sequencing. Compared with WT mice, adiponectin KO mice fed a chow diet exhibited decreased mRNA expression of rate-limiting enzymes in several important glucose and lipid metabolic pathways, including glycolysis, tricarboxylic acid cycle, fatty-acid activation and synthesis, triglyceride synthesis, and cholesterol synthesis. In addition, binding of the transcription factor Hnf4a to DNAs encoding several key metabolic enzymes was reduced in KO mice, suggesting that adiponectin might regulate hepatic gene expression via Hnf4a. Phenotypically, adiponectin KO mice possessed smaller epididymal fat pads and showed reduced body weight compared with WT mice. When fed a high-fat diet, adiponectin KO mice showed significantly reduced lipid accumulation in the liver. These lipogenic defects are consistent with the down-regulation of lipogenic genes in the KO mice.
脂联素在转录水平上对肝脏葡萄糖和脂质代谢的影响在很大程度上尚不清楚。我们通过 RNA 测序对脂联素敲除 (KO) 和野生型 (WT) 小鼠的肝脏基因表达进行了分析。与 WT 小鼠相比,给予普通饮食的脂联素 KO 小鼠几种重要的葡萄糖和脂质代谢途径中的限速酶的 mRNA 表达降低,包括糖酵解、三羧酸循环、脂肪酸激活和合成、甘油三酯合成和胆固醇合成。此外,KO 小鼠中转录因子 Hnf4a 与编码几种关键代谢酶的 DNA 的结合减少,表明脂联素可能通过 Hnf4a 调节肝脏基因表达。表型上,脂联素 KO 小鼠的附睾脂肪垫较小,体重较 WT 小鼠减轻。给予高脂肪饮食时,脂联素 KO 小鼠肝脏的脂质积累明显减少。这些脂肪生成缺陷与 KO 小鼠中脂肪生成基因的下调一致。