Table_5_Proerythroblast Cells of Diamond-Blackfan Anemia Patients With RPS19 and CECR1 Mutations Have Similar Transcriptomic Signature.XLSX

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.

黑扇贝贫血症（DBA）是一种遗传性骨髓（BM）衰竭综合征，其特征为红细胞分化不足。DBA主要由核糖体蛋白基因突变引起，因此被归类为核糖体病。然而，在约30%的患者中，其分子病因无法被发现。RPS19基因型突变导致了25%的病例。另一方面，CECR1突变也会引起与DBA相似但并非核糖体病的表型。鉴于骨髓中红细胞生成的阻滞，本研究对DBA患者的骨髓定居细胞三种不同类型的细胞进行了转录组分析，并将结果与健康捐赠者进行了比较。从骨髓穿刺物中分离出骨髓单核细胞（MNCs），然后对造血干细胞（HSC）[CD71-CD34+ CD38mo/lo]、巨核细胞-红细胞祖细胞（MEP）[CD71-CD34+ CD38hi]和原红细胞[CD71+ CD117+ CD38+]进行分选和分析。在这些细胞中，原红细胞具有最显著的转录组特征。与细胞应激/免疫反应相关的基因增加，并且在DBA原红细胞中，一些在红细胞分化中起作用的转录因子的表达发生改变。我们还发现，DBA原红细胞中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患者红细胞分化失败的功能证据。根据我们发现的所有类似RPS19和CECR1突变的患者都具有共同的转录组特征，推测炎症性骨髓微环境可能在DBA发病机制中发挥作用。