BIGR, UMR_S1134, Inserm, Université de Paris, F-75015 Paris, France.
Institut National de la Transfusion Sanguine, F-75015 Paris, France.
Cells. 2021 Dec 24;11(1):49. doi: 10.3390/cells11010049.
Over 95% of Polycythemia Vera (PV) patients carry the V617F mutation in the tyrosine kinase Janus kinase 2 (JAK2), resulting in uncontrolled erythroid proliferation and a high risk of thrombosis. Using mass spectrometry, we analyzed the RBC membrane proteome and showed elevated levels of multiple Ca binding proteins as well as endoplasmic-reticulum-residing proteins in PV RBC membranes compared with RBC membranes from healthy individuals. In this study, we investigated the impact of JAK2 on (1) calcium homeostasis and RBC ion channel activity and (2) protein expression and sorting during terminal erythroid differentiation. Our data from automated patch-clamp show modified calcium homeostasis in PV RBCs and cell lines expressing JAK2, with a functional impact on the activity of the Gárdos channel that could contribute to cellular dehydration. We show that JAK2 could play a role in organelle retention during the enucleation step of erythroid differentiation, resulting in modified whole cell proteome in reticulocytes and RBCs in PV patients. Given the central role that calcium plays in the regulation of signaling pathways, our study opens new perspectives to exploring the relationship between JAK2, calcium homeostasis, and cellular abnormalities in myeloproliferative neoplasms, including cellular interactions in the bloodstream in relation to thrombotic events.
超过 95%的真性红细胞增多症 (PV) 患者存在酪氨酸激酶 Janus 激酶 2 (JAK2) 的 V617F 突变,导致不受控制的红细胞增殖和高血栓风险。我们使用质谱分析法分析了 RBC 膜蛋白质组,结果显示与健康个体的 RBC 膜相比,PV RBC 膜中存在多种 Ca 结合蛋白和内质网驻留蛋白的水平升高。在这项研究中,我们研究了 JAK2 对 (1) 钙稳态和 RBC 离子通道活性以及 (2) 终末红细胞分化过程中的蛋白质表达和分拣的影响。我们的自动化膜片钳数据显示,PV RBC 和表达 JAK2 的细胞系中钙稳态发生改变,对 Gárdos 通道的活性有功能影响,这可能导致细胞脱水。我们表明 JAK2 在红细胞分化的去核步骤中可能在细胞器保留中发挥作用,导致 PV 患者的网织红细胞和 RBC 中整个细胞蛋白质组发生改变。鉴于钙在调节信号通路方面的核心作用,我们的研究为探索 JAK2、钙稳态和骨髓增殖性肿瘤中的细胞异常之间的关系开辟了新的视角,包括与血栓事件相关的血液中细胞间相互作用。