Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand.
J Transl Med. 2011 Jun 25;9:96. doi: 10.1186/1479-5876-9-96.
Hemoglobin E/β-thalassemia is particularly common in Southeast Asia and has variable symptoms ranging from mild to severe anemia. Previous investigations demonstrated the remarkable symptoms of β-thalassemia in terms of the acceleration of apoptotic cell death. Ineffective erythropoiesis has been studied in human hematopoietic stem cells, however the distinct apoptotic mechanism was unclear.
The phosphoproteome of bone marrow HSCs/CD34⁺ cells from HbE/β-thalassemic patients was analyzed using IMAC phosphoprotein isolation followed by LC-MS/MS detection. Decyder MS software was used to quantitate differentially expressed proteins in 3 patients and 2 normal donors. The differentially expressed proteins from HSCs/CD34⁺ cells were compared with HbE/β-thalassemia and normal HSCs.
A significant change in abundance of 229 phosphoproteins was demonstrated. Importantly, the analysis of the candidate proteins revealed a high abundance of proteins that are commonly found in apoptotic cells including cytochrome C, caspase 6 and apoptosis inducing factors. Moreover, in the HSCs patients a significant increase was observed in a specific type of phosphoserine/threonine binding protein, which is known to act as an important signal mediator for the regulation of cell survival and apoptosis in HbE/β-thalassemia.
Our study used a novel method to investigate proteins that influence a particular pathway in a given disease or physiological condition. Ultimately, phosphoproteome profiling in HbE/β-thalassemic stem cells is an effective method to further investigate the cell death mechanism of ineffective erythropoiesis in β-thalassemia. Our report provides a comprehensive phosphoproteome, an important resource for the study of ineffective erythropoiesis and developing therapies for HbE/β-thalassemia.
血红蛋白 E/β-地中海贫血在东南亚尤为常见，其症状从轻度到重度贫血不等，具有多变性。之前的研究表明，β-地中海贫血在加速细胞凋亡死亡方面具有显著的症状。已在人类造血干细胞中研究了无效造血，但确切的凋亡机制尚不清楚。
采用 IMAC 磷酸蛋白分离法联合 LC-MS/MS 检测，分析来自 HbE/β-地中海贫血患者骨髓 HSCs/CD34+细胞的磷酸蛋白质组。使用 Decyder MS 软件对 3 例患者和 2 例正常供体的差异表达蛋白进行定量分析。将 HSCs/CD34+细胞中的差异表达蛋白与 HbE/β-地中海贫血和正常 HSCs 进行比较。
显示出 229 种磷酸蛋白丰度的显著变化。重要的是，对候选蛋白的分析表明，凋亡细胞中常见的高丰度蛋白，包括细胞色素 C、半胱天冬酶 6 和凋亡诱导因子。此外，在 HSCs 患者中，一种特定类型的磷酸丝氨酸/苏氨酸结合蛋白的含量显著增加，这种蛋白已知在 HbE/β-地中海贫血中作为调节细胞存活和凋亡的重要信号介质。
本研究采用一种新方法研究影响特定疾病或生理状况中特定途径的蛋白质。最终，HbE/β-地中海贫血干细胞的磷酸蛋白质组谱分析是进一步研究β-地中海贫血无效造血细胞死亡机制的有效方法。我们的报告提供了一个全面的磷酸蛋白质组，这是研究无效造血和开发 HbE/β-地中海贫血治疗方法的重要资源。
