Luo Yuan-Yuan, Ruan Chang-Shun, Zhao Fu-Zhen, Yang Min, Cui Wei, Cheng Xi, Luo Xiao-He, Zhang Xian-Xiang, Zhang Cheng
Department of Endocrinology, Chongqing University Three Gorges Hospital, Chongqing, China; Chongqing Municipality Clinical Research Center for Endocrinology and Metabolic Diseases, Chongqing University Three Gorges Hospital, Chongqing, China; Department of Endocrinology, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China.
Chongqing Municipality Clinical Research Center for Endocrinology and Metabolic Diseases, Chongqing University Three Gorges Hospital, Chongqing, China; Department of Central Laboratory, Chongqing University Three Gorges Hospital, School of Medicine, Chongqing University, Chongqing, China.
Metabolism. 2025 Jan;162:156049. doi: 10.1016/j.metabol.2024.156049. Epub 2024 Oct 24.
Elevated hepatic glucose production (HGP) is a prominent manifestation of impaired hepatic glucose metabolism in individuals with diabetes. Increased hepatic gluconeogenesis plays a pivotal role in the dysregulation of hepatic glucose metabolism and contributes significantly to fasting hyperglycemia in diabetes. Previous studies have identified zinc-finger BED domain-containing 3 (ZBED3) as a risk gene for type 2 diabetes (T2DM), and its single nucleotide polymorphism (SNPs) is closely associated with the fasting blood glucose level, suggesting a potential correlation between ZBED3 and the onset of diabetes. This study primarily explores the effect of ZBED3 on hepatic gluconeogenesis and analyzes the relevant signaling pathways that regulate hepatic gluconeogenesis.
The expression level of ZBED3 was assessed in the liver of insulin-resistant (IR)-related disease. RNA-seq and bioinformatics analyses were employed to examine the ZBED3-related pathway that modulated HGP. To investigate the role of ZBED3 in hepatic gluconeogenesis, the expression of ZBED3 was manipulated by upregulation or silencing using adeno-associated virus (AAV) in mouse primary hepatocytes (MPHs) and HHL-5 cells. In vivo, hepatocyte-specific ZBED3 knockout mice were generated. Moreover, AAV8 was employed to achieve hepatocyte-specific overexpression and knockdown of ZBED3 in C57BL/6 and db/db mice. Immunoprecipitation and mass spectrometry (IP-MS) analyses were employed to identify proteins that interacted with ZBED3. Co-immunoprecipitation (co-IP), glutathione S-transferase (GST) - pulldown, and dual-luciferase reporter assays were conducted to further elucidate the underlying mechanism of ZBED3 in regulating hepatic gluconeogenesis.
The expression of ZBED3 in the liver of IR-related disease models was found to be increased. Under the stimulation of glucagon, ZBED3 promoted the expression of hepatic gluconeogenesis-related genes PGC1A, PCK1, G6PC, thereby increasing HGP. Consistently, the rate of hepatic gluconeogenesis was found to be elevated in mice with hepatocyte-specific overexpression of ZBED3 and decreased in those with ZBED3 knockout. Additionally, the knockdown of ZBED3 in the liver of db/db mice resulted in a reduction in hepatic gluconeogenesis. Moreover, the study revealed that ZBED3 facilitated the nuclear translocation of protein arginine methyltransferases 5 (PRMT5) to influence the regulation of PRMT5-mediated symmetrical dimethylation of arginine (s-DMA) of cyclic adenosine monophosphate (cAMP) response element binding protein (CREB), which in turn affects the phosphorylation of CREB and ultimately promotes HGP.
This study indicates that ZBED3 promotes hepatic gluconeogenesis and serves as a critical regulator of the progression of diabetes.
肝葡萄糖生成（HGP）升高是糖尿病患者肝葡萄糖代谢受损的一个突出表现。肝糖异生增加在肝葡萄糖代谢失调中起关键作用，并对糖尿病患者的空腹高血糖有显著影响。既往研究已将含锌指BED结构域蛋白3（ZBED3）鉴定为2型糖尿病（T2DM）的一个风险基因，其单核苷酸多态性（SNPs）与空腹血糖水平密切相关，提示ZBED3与糖尿病发病之间可能存在关联。本研究主要探讨ZBED3对肝糖异生的影响，并分析调节肝糖异生的相关信号通路。
评估胰岛素抵抗（IR）相关疾病肝脏中ZBED3的表达水平。采用RNA测序和生物信息学分析来检测调节HGP的ZBED3相关通路。为研究ZBED3在肝糖异生中的作用，在小鼠原代肝细胞（MPHs）和HHL-5细胞中使用腺相关病毒（AAV）通过上调或沉默来调控ZBED3的表达。在体内，构建肝细胞特异性ZBED3敲除小鼠。此外，使用AAV8在C57BL/6和db/db小鼠中实现肝细胞特异性过表达和敲低ZBED3。采用免疫沉淀和质谱（IP-MS）分析来鉴定与ZBED3相互作用的蛋白质。进行免疫共沉淀（co-IP）、谷胱甘肽S-转移酶（GST）下拉实验和双荧光素酶报告基因检测，以进一步阐明ZBED3调节肝糖异生的潜在机制。
发现IR相关疾病模型肝脏中ZBED3的表达增加。在胰高血糖素刺激下，ZBED3促进肝糖异生相关基因PGC1A、PCK1、G6PC的表达，从而增加HGP。同样，在肝细胞特异性过表达ZBED3的小鼠中肝糖异生速率升高，而在ZBED3敲除小鼠中降低。此外，在db/db小鼠肝脏中敲低ZBED3导致肝糖异生减少。而且，该研究表明ZBED3促进蛋白精氨酸甲基转移酶5（PRMT5）的核转位，以影响PRMT5介导的环磷酸腺苷（cAMP）反应元件结合蛋白（CREB）精氨酸对称二甲基化（s-DMA）的调节，进而影响CREB的磷酸化并最终促进HGP。
本研究表明ZBED3促进肝糖异生，并作为糖尿病进展的关键调节因子。
