Data_Sheet_5_Proerythroblast Cells of Diamond-Blackfan Anemia Patients With RPS19 and CECR1 Mutations Have Similar Transcriptomic Signature.PDF

Diamond Blackfan Anemia (DBA) is an inherited bone marrow (BM) failure syndrome, characterized by a paucity of erythroid differentiation. DBA is mainly caused by the mutations in ribosomal protein genes, hence classified as ribosomopathy. However, in approximately 30% of patients, the molecular etiology cannot be discovered. RPS19 germline mutations caused 25% of the cases. On the other hand, CECR1 mutations also cause phenotypes similar to DBA but not being a ribosomopathy. Due to the blockade of erythropoiesis in the BM, we investigated the transcriptomic profile of three different cell types of BM resident cells of DBA patients and compared them with healthy donors. From BM aspirates BM mononuclear cells (MNCs) were isolated and hematopoietic stem cells (HSC) [CD71–CD34+ CD38mo/lo], megakaryocyte–erythroid progenitor cells (MEP) [CD71–CD34+ CD38hi] and Proerythroblasts [CD71+ CD117+ CD38+] were sorted and analyzed with a transcriptomic approach. Among all these cells, proerythroblasts had the most different transcriptomic profile. The genes associated with cellular stress/immune responses were increased and some of the transcription factors that play a role in erythroid differentiation had altered expression in DBA proerythroblasts. We also showed that gene expression levels of ribosomal proteins were decreased in DBA proerythroblasts. In addition to these, colony formation assay (CFU-E) provided functional evidence of the failure of erythroid differentiation in DBA patients. According to our findings that all patients resembling both RPS19 and CECR1 mutations have common transcriptomic signatures, it may be possible that inflammatory BM niche may have a role in DBA pathogenesis.

戴蒙德-布莱克范贫血（Diamond Blackfan Anemia, DBA）是一种遗传性骨髓衰竭综合征，以红细胞分化缺乏为主要特征。DBA主要由核糖体蛋白基因突变所致，因此被归类为核糖体病。然而，约30%的患者无法明确其分子病因。RPS19生殖系突变可导致25%的DBA病例。另一方面，CECR1基因突变亦可引发与DBA相似的表型，但不属于核糖体病范畴。由于骨髓中红细胞生成受阻，本研究对DBA患者骨髓常驻细胞的三种不同细胞类型进行了转录组谱分析，并与健康供者进行对比。研究人员从骨髓穿刺液中分离得到骨髓单个核细胞（MNCs），并分选得到造血干细胞（HSC）[CD71–CD34+ CD38mo/lo]、巨核细胞-红细胞祖细胞（MEP）[CD71–CD34+ CD38hi]及早幼红细胞[CD71+ CD117+ CD38+]，随后通过转录组学方法进行分析。在所有上述细胞中，早幼红细胞的转录组谱差异最为显著。DBA早幼红细胞中，与细胞应激/免疫反应相关的基因表达上调，部分参与红细胞分化的转录因子表达亦发生改变。研究同时发现，DBA早幼红细胞内核糖体蛋白的基因表达水平降低。此外，集落形成实验（CFU-E）为DBA患者的红细胞分化缺陷提供了功能学证据。基于所有兼具RPS19和CECR1突变特征的患者均存在共同转录组特征这一研究结果，提示炎症性骨髓微环境可能在DBA的发病机制中发挥作用。