METHODS: Expression levels of ZBED3 were assessed in individuals with MASLD, as well as in cellular and animal models of MASLD. In vitro and in vivo analyses were conducted using a cellular model of MASLD induced by NEFA and an animal model of MASLD induced by a high-fat diet (HFD), respectively, to investigate the role of ZBED3 in MASLD. ZBED3 expression was increased by lentiviral infection or tail-vein injection of adeno-associated virus. RNA-seq and bioinformatics analysis were employed to examine the pathways through which ZBED3 modulates lipid accumulation. Findings from these next-generation transcriptome sequencing studies indicated that ZBED3 controls SREBP1c (also known as SREBF1; a gene involved in fatty acid de novo synthesis); thus, co-immunoprecipitation and LC-MS/MS were utilised to investigate the molecular mechanisms by which ZBED3 regulates the sterol regulatory element binding protein 1c (SREBP1c).
RESULTS: In this study, we found that ZBED3 was significantly upregulated in the liver of individuals with MASLD and in MASLD animal models. ZBED3 overexpression promoted NEFA-induced triglyceride accumulation in hepatocytes in vitro. Furthermore, the hepatocyte-specific overexpression of Zbed3 promoted hepatic steatosis. Conversely, the hepatocyte-specific knockout of Zbed3 resulted in resistance of HFD-induced hepatic steatosis. Mechanistically, ZBED3 interacts directly with polypyrimidine tract-binding protein 1 (PTBP1) and affects its binding to the SREBP1c mRNA precursor to regulate SREBP1c mRNA stability and alternative splicing.
CONCLUSIONS: This study indicates that ZBED3 promotes hepatic steatosis and serves as a critical regulator of the progression of MASLD.
METHODS: RNA-seq data have been deposited in the NCBI Gene Expression Omnibus ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE231875 ). MS proteomics data have been deposited to the ProteomeXchange Consortium via the iProX partner repository ( https://proteomecentral.proteomexchange.org/cgi/GetDataset?ID=PXD041743 ).
方法:在患有MASLD的个体中评估ZBED3的表达水平,以及MASLD的细胞和动物模型。使用NEFA诱导的MASLD细胞模型和高脂饮食(HFD)诱导的MASLD动物模型进行体外和体内分析。分别,探讨ZBED3在MASLD中的作用。ZBED3表达通过慢病毒感染或腺相关病毒的尾静脉注射而增加。采用RNA-seq和生物信息学分析来检查ZBED3调节脂质积累的途径。这些下一代转录组测序研究的发现表明,ZBED3控制SREBP1c(也称为SREBF1;参与脂肪酸从头合成的基因);因此,免疫共沉淀和LC-MS/MS用于研究ZBED3调节固醇调节元件结合蛋白1c(SREBP1c)的分子机制。
结果:在这项研究中,我们发现ZBED3在MASLD患者和MASLD动物模型的肝脏中显著上调.ZBED3过表达促进NEFA诱导的甘油三酯在体外肝细胞中的积累。此外,肝细胞特异性Zbed3过表达促进肝脏脂肪变性.相反,肝细胞特异性敲除Zbed3导致HFD诱导的肝脂肪变性耐药.机械上,ZBED3直接与聚嘧啶束结合蛋白1(PTBP1)相互作用,并影响其与SREBP1cmRNA前体的结合,以调节SREBP1cmRNA的稳定性和可变剪接。
结论:本研究表明ZBED3促进肝脂肪变性,并作为MASLD进展的关键调节因子。
方法:RNA-seq数据已保存在NCBI基因表达Omnibus中(www。ncbi.nlm.nih.gov/geo/query/acc。cgi?acc=GSE231875)。MS蛋白质组学数据已通过iProX合作伙伴存储库(https://proteomecentral。proteomexchange.org/cgi/GetDataset?ID=PXD041743)。