Liver Center, Division of Gastroenterology, Massachusetts General Hospital, Boston, MA 02114, USA; Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA.
Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA.
Cell Metab. 2024 Jan 2;36(1):144-158.e7. doi: 10.1016/j.cmet.2023.11.010. Epub 2023 Dec 14.
Common genetic variants in glucokinase regulator (GCKR), which encodes GKRP, a regulator of hepatic glucokinase (GCK), influence multiple metabolic traits in genome-wide association studies (GWASs), making GCKR one of the most pleiotropic GWAS loci in the genome. It is unclear why. Prior work has demonstrated that GCKR influences the hepatic cytosolic NADH/NAD ratio, also referred to as reductive stress. Here, we demonstrate that reductive stress is sufficient to activate the transcription factor ChREBP and necessary for its activation by the GKRP-GCK interaction, glucose, and ethanol. We show that hepatic reductive stress induces GCKR GWAS traits such as increased hepatic fat, circulating FGF21, and circulating acylglycerol species, which are also influenced by ChREBP. We define the transcriptional signature of hepatic reductive stress and show its upregulation in fatty liver disease and downregulation after bariatric surgery in humans. These findings highlight how a GCKR-reductive stress-ChREBP axis influences multiple human metabolic traits.
葡萄糖激酶调节蛋白(GCKR)基因中的常见遗传变异可编码 GKRP,后者是肝葡萄糖激酶(GCK)的调节蛋白。在全基因组关联研究(GWAS)中,这些变异与多种代谢特征相关,使 GCKR 成为基因组中最具多效性的 GWAS 基因座之一。其原因尚不清楚。先前的研究表明,GCKR 影响肝胞质 NADH/NAD 比,也称为还原性应激。在这里,我们证明还原性应激足以激活转录因子 ChREBP,并且是 GKRP-GCK 相互作用、葡萄糖和乙醇激活 ChREBP 所必需的。我们表明肝还原性应激诱导 GCKR GWAS 特征,如增加肝脂肪、循环 FGF21 和循环酰基甘油种类,这些也受 ChREBP 影响。我们定义了肝还原性应激的转录特征,并表明其在脂肪肝疾病中的上调和人类减肥手术后的下调。这些发现强调了 GCKR-还原性应激-ChREBP 轴如何影响多种人类代谢特征。