Primary myelofibrosis (PMF) is a myeloid proliferative neoplasm (MPN) characterized by bone marrow (BM) fibrosis. Pre-fibrotic PMF (pre-PMF) progresses to overt PMF. Megakaryocytes (MKs) play a primary role in PMF; however, the functions of MK subsets and those of other hematopoietic cells during PMF progression remain unclarified. Therefore, we analyzed BM aspirates in pre-PMFs, overt PMFs, and other MPNs using single-cell RNA sequencing (scRNA-seq). We identified 14 cell types with subsets, including hematopoietic stem and progenitor cells (HSPCs) and MKs. HSPCs in overt PMF were MK-biased and inflammation/fibrosis-enriched. Among MKs, the epithelial-mesenchymal transition (EMT)-enriched subset was abruptly increased in overt PMF. MKs in non-fibrotic/non-PMF MPN were MK differentiation-enriched, whereas those in fibrotic/non-PMF MPN were inflammation/fibrosis-enriched. Overall, the inflammation/fibrosis signatures of the HSPC, MK, and CD14+ monocyte subsets increased from pre-PMF to overt PMF. Cytotoxic and dysfunctional scores also increased in T and NK cells. Clinically, MK and HSPC subsets with high inflammation/fibrosis signatures were frequent in the patients with peripheral blood blasts ≥1%. scRNA-seq predicted higher cellular communications of MK differentiation, inflammation/fibrosis, immunologic effector/dysfunction, and tumor-associated signaling in overt PMF than pre-PMF. However, no decisive subset emerged during PMF progression. Our study demonstrated that HSPCs, monocytes, and lymphoid cells contribute to PMF progression, and subset specificity existed regarding inflammation/fibrosis and immunologic dysfunction. PMF progression may depend on multiple cell types' alterations, and EMTenriched MKs may be potential targets for the diagnosis and therapy of the progression.

中文翻译：

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纤维化前和显性原发性骨髓纤维化之间的不同炎症、纤维化和免疫学特征。


原发性骨髓纤维化 （PMF） 是一种以骨髓 （BM） 纤维化为特征的骨髓增生性肿瘤 （MPN）。前纤维化 PMF （pre-PMF） 进展为显性 PMF。巨核细胞 （MKs） 在 PMF 中起主要作用;然而，MK 亚群和其他造血细胞在 PMF 进展过程中的功能仍未阐明。因此，我们使用单细胞 RNA 测序 （scRNA-seq） 分析了前 PMF 、显性 PMF 和其他 MPN 中的 BM 抽吸物。我们鉴定了 14 种细胞类型及其子集，包括造血干细胞和祖细胞 （HSPCs） 和 MKs。显性 PMF 中的 HSPC 是 MK 偏倚的和炎症/纤维化丰富的。在 MK 中，上皮-间充质转化 （EMT） 富集的亚群在显性 PMF 中突然增加。非纤维化/非 PMF MPN 中的 MK 是 MK 分化富集的，而纤维化/非 PMF MPN 中的 MK 是炎症/纤维化富集的。总体而言，HSPC 、 MK 和 CD14 + 单核细胞亚群的炎症/纤维化特征从 pre-PMF 增加到显性 PMF。T 和 NK 细胞的细胞毒性和功能功能障碍评分也有所增加。临床上，具有高炎症/纤维化特征的 MK 和 HSPC 亚群在外周原始血细胞患者中很常见 ≥1%。scRNA-seq 预测显性 PMF 中 MK 分化、炎症/纤维化、免疫效应/功能障碍和肿瘤相关信号传导的细胞通讯高于 pre-PMF。然而，在 PMF 进展过程中没有出现决定性的子集。我们的研究表明，HSPCs 、 单核细胞 和 淋巴细胞 有助于 PMF 进展，并且在炎症/纤维化和免疫功能障碍方面存在亚群特异性。 PMF 进展可能取决于多种细胞类型的改变，EMT 富集的 MK 可能是诊断和治疗进展的潜在靶标。