Regulation of hepatic gluconeogenesis by nuclear factor Y transcription factor in mice
Regulation of hepatic gluconeogenesis by nuclear factor Y transcription factor in mice
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核因子Y转录因子对小鼠肝脏糖异生的调节
DOI：
10.1074/jbc.ra117.000508
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发表时间：
2018-05-18
影响因子：
4.8
通讯作者：
Su, Zhiguang
中科院分区：
文献类型：
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作者：
Zhang, Yanjie;Guan, Qiuyue;Su, Zhiguang
肝脏糖异生对于维持血糖水平至关重要，其异常激活会导致高血糖和 2 型糖尿病。然而，肝脏糖异生调节的分子机制仍有待完全明确。在本研究中，我们利用小鼠肝细胞和肝脏特异性敲除小鼠模型，探讨了核因子Y（NF-Y）在调节肝糖代谢中的生理作用及其潜在机制。我们发现 NF-Y 靶向肝脏中的糖异生途径。 cAMP、胰高血糖素和体内禁食可有效诱导肝脏 NF-Y 表达。与空载体对照细胞相比，慢病毒介导的 Hepa1-6 肝细胞中 NF-Y 过表达显着提高了糖异生基因表达和细胞葡萄糖产量。相反，CRISPR/Cas9 介导的 NF-Y 亚基 A (NF-YA) 敲低会减弱糖异生基因表达和葡萄糖产生。我们还提供证据表明 CRE-loxP 介导的肝脏特异性 NF-YA 敲除会损害肝脏葡萄糖的产生。从机制上讲，荧光素酶报告基因测定和 ChIP 分析表明，NF-Y 通过直接结合其启动子中的 CCAAT 调控序列基序，分别编码磷酸烯醇丙酮酸羧激酶 (PEPCK) 和葡萄糖 6 磷酸酶催化亚基 (G6Pase)，从而激活糖异生基因 Pck1 和 G6pc 的转录。值得注意的是，NF-Y 通过与 cAMP 反应元件结合蛋白 (CREB) 相互作用来增强糖异生。总的来说，我们的结果揭示了 NF-Y 通过上调糖异生基因 Pck1 和 G6pc 来控制葡萄糖代谢的先前未被认识的生理功能。因此，调节肝脏 NF-Y 表达可能为控制 2 型糖尿病提供一种有吸引力的治疗方法。
Hepatic gluconeogenesis is essential to maintain blood glucose levels, and its abnormal activation leads to hyperglycemia and type 2 diabetes. However, the molecular mechanisms in the regulation of hepatic gluconeogenesis remain to be fully defined. In this study, using murine hepatocytes and a liver-specific knockout mouse model, we explored the physiological role of nuclear factor Y (NF-Y) in regulating hepatic glucose metabolism and the underlying mechanism. We found that NF-Y targets the gluconeogenesis pathway in the liver. Hepatic NF-Y expression was effectively induced by cAMP, glucagon, and fasting in vivo. Lentivirus-mediated NF-Y overexpression in Hepa1-6 hepatocytes markedly raised the gluconeogenic gene expression and cellular glucose production compared with empty vector control cells. Conversely, CRISPR/Cas9-mediated knockdown of NF-Y subunit A (NF-YA) attenuated gluconeogenic gene expression and glucose production. We also provide evidence indicating that CRE-loxP-mediated, liver-specific NF-YA knockout compromises hepatic glucose production. Mechanistically, luciferase reporter gene assays and ChIP analysis indicated that NF-Y activates transcription of the gluconeogenic genes Pck1 and G6pc, by encoding phosphoenolpyruvate carboxykinase (PEPCK) and the glucose-6-phosphatase catalytic subunit (G6Pase), respectively, via directly binding to the CCAAT regulatory sequence motif in their promoters. Of note, NF-Y enhanced gluconeogenesis by interacting with cAMP-responsive element–binding protein (CREB). Overall, our results reveal a previously unrecognized physiological function of NF-Y in controlling glucose metabolism by up-regulating the gluconeogenic genes Pck1 and G6pc. Modulation of hepatic NF-Y expression may therefore offer an attractive therapeutic approach to manage type 2 diabetes.