Cardona Cameron, Young Madelyne, Montgomery McKale
Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
Department of Nutritional Sciences, Texas Christian University, Fort Worth, TX 76109, USA.
Int J Mol Sci. 2025 Aug 28;26(17):8359. doi: 10.3390/ijms26178359.
Activation of TP53 signaling during ribosome biogenesis is an essential part of erythroid development, whereas the pathologic activation of TP53 in ribosomopathies such as Diamond-Blackfan anemia (DBA) and del (5q) myelodysplastic syndrome (MDS) prevents the normal expansion of erythroid precursors. TP53 can also be linked to the pathogenesis of DBA and MDS via ferroptosis, a form of iron-mediated cell death propagated by excess polyunsaturated fatty acid-containing oxidizable phospholipids and loss of lipid peroxide repair capacity. The primary objective of this work was to establish how overexpression and mutation of the TP53 gene influences lipid composition, erythroid differentiation, and ferroptosis sensitivity in K-562 cells, an in vitro model for studying erythropoiesis. Employing a reverse genetics approach, we generated four isogenic cell lines that either lacked functional TP53 expression, expressed wild-type (WT) TP53, or expressed one of the two most common TP53 mutation types, R175H or R282W. We then utilized non-targeted lipidomics to quantify and identify changes in specific lipid species that occur with induction of WT and mutant TP53 expression. We also analyzed differences in gene expression, ferroptosis sensitivity, and hemoglobinization by qPCR, CCK-8 cytotoxicity assay, and o-dianisidine staining, respectively. The abundance of 337 distinct lipid species was impacted by induction of WT TP53 expression compared to K-562 cells expressing a nonfunctional P53 protein. Yet only 17 lipid compounds were differentially impacted between cells expressing WT TP53 and either of the mutant TP53 genes tested. Similarly, while the TP53 null K-562 cells displayed modest sensitivity to ferroptosis, cells expressing both WT and mutant TP53 genes were remarkably resistant to ferroptosis. However, terminal differentiation and hemoglobinization were significantly impacted in R175H mutant TP53-expressing K-562 cells. Findings from this work provide novel insights into the role of TP53 in lipid metabolism and terminal erythropoiesis.
核糖体生物合成过程中TP53信号的激活是红系发育的重要组成部分，而在如先天性纯红细胞再生障碍性贫血（DBA）和5号染色体长臂缺失（del(5q)）骨髓增生异常综合征（MDS）等核糖体病中TP53的病理性激活会阻止红系前体细胞的正常扩增。TP53还可通过铁死亡与DBA和MDS的发病机制相关联，铁死亡是一种由过量含多不饱和脂肪酸的可氧化磷脂和脂质过氧化物修复能力丧失所引发的铁介导的细胞死亡形式。这项工作的主要目的是确定TP53基因的过表达和突变如何影响K-562细胞中的脂质组成、红系分化和铁死亡敏感性，K-562细胞是一种用于研究红细胞生成的体外模型。采用反向遗传学方法，我们生成了四种同基因细胞系，它们要么缺乏功能性TP53表达，要么表达野生型（WT）TP53，要么表达两种最常见的TP53突变类型之一，即R175H或R282W。然后，我们利用非靶向脂质组学来定量和鉴定随着WT和突变型TP53表达的诱导而发生的特定脂质种类的变化。我们还分别通过qPCR、CCK-8细胞毒性试验和邻联茴香胺染色分析了基因表达、铁死亡敏感性和血红蛋白化的差异。与表达无功能P53蛋白的K-562细胞相比，WT TP53表达的诱导影响了337种不同脂质种类的丰度。然而，在表达WT TP53的细胞与所测试的任一突变型TP53基因的细胞之间，只有17种脂质化合物受到不同的影响。同样，虽然TP53基因缺失的K-562细胞对铁死亡表现出适度的敏感性，但表达WT和突变型TP53基因的细胞对铁死亡具有显著的抗性。然而，在表达R175H突变型TP53的K-562细胞中，终末分化和血红蛋白化受到了显著影响。这项工作得出的结果为TP53在脂质代谢和终末红细胞生成中的作用提供了新的见解。
