IL-1 receptor antagonist prevents bias to myelopoiesis in hematopoietic stem cells and protects from neoplasia

Interleukin-1β (IL-1β) drives hematopoietic stem cell (HSC) differentiation into the myeloid lineage, and enhanced IL-1β signaling plays a key role in hematological malignancies. However, little is known on the role of its endogenous regulatory cytokine, IL-1 receptor antagonist (IL-1rn), on both healthy and malignant hematopoiesis. Here, we show that inflammation through unbalanced IL-1rn is present in the experimental model of acute myeloid leukemia (AML) driven by the NRAS-G12D oncogene. Total RNA was isolated from bone marrow (BM) HSC subsets of Mx1-Cre NRAS-G12D mice (IL-1rn-KO, n=3) and NRAS-G12D control (n=3) mic, 6 weeks after pI:pC injection. HSC were FACS sorted and immunophenotypically defined as follows: lin− c-kit+ Sca-1+ (LSK) CD34- Flt3- long term hematopoietic stem cells (LT-HSC), LSK CD34+ Flt3- short term HSC (ST-HSC) and LSK CD34+ Flt3+ multipotent progenitors (MPP). RNA was amplified and prepared for RNA-Seq using the SMART-Seq v4 Ultra Low Input RNA kit (Clontech).

白细胞介素-1β（Interleukin-1β, IL-1β）可驱动造血干细胞（hematopoietic stem cell, HSC）向髓系分化，而异常增强的IL-1β信号通路在血液系统恶性肿瘤中发挥关键作用。然而，其内源调节细胞因子白细胞介素-1受体拮抗剂（IL-1 receptor antagonist, IL-1rn）在生理及恶性造血过程中的作用仍有待阐明。本研究发现，在NRAS-G12D癌基因驱动的急性髓系白血病（acute myeloid leukemia, AML）实验模型中，存在IL-1rn失衡介导的炎症状态。我们从聚肌苷酸-聚胞苷酸（polyinosinic-polycytidylic acid, pI:pC）注射6周后的Mx1-Cre NRAS-G12D白细胞介素-1受体拮抗剂敲除（IL-1rn knockout, IL-1rn-KO）小鼠（n=3）及NRAS-G12D对照小鼠（n=3）的骨髓（bone marrow, BM）造血干细胞亚群中分离总RNA。通过荧光激活细胞分选（Fluorescence-activated cell sorting, FACS），按照免疫表型将造血干细胞分为以下亚群：谱系阴性c-kit+Sca-1+（LSK）CD34-Flt3- 长期造血干细胞（long-term hematopoietic stem cell, LT-HSC）、LSK CD34+Flt3- 短期造血干细胞（short-term hematopoietic stem cell, ST-HSC）以及LSK CD34+Flt3+ 多能祖细胞（multipotent progenitor, MPP）。随后采用SMART-Seq v4超低起始量RNA试剂盒（Clontech）对RNA进行扩增并制备RNA测序文库。