Single-cell analysis of cultured bone marrow stromal cells reveals high similarity to fibroblasts in situ

Within the heterogenous pool of bone marrow stromal cells, mesenchymal stromal cells (MSCs) are of particular interest because of their hematopoiesis-supporting capacities, contribution to disease progression, therapy resistance, and leukemic initiation. Cultured bone marrow-derived stromal cells (cBMSCs) are used for in vitro modeling of hematopoiesis-stroma interactions, validation of disease mechanisms, and screening for therapeutic targets. Here, we place cBMSCs (mouse and human) in a bone marrow tissue context by systematically comparing the transcriptome of plastic-adherent cells on a single-cell level with in vivo counterparts. Cultured BMSCs encompass a rather homogenous cell population, independent of the isolation method used and, although still possessing hematopoiesis-supporting capacity, are distinct from freshly isolated MSCs and more akin to in vivo fibroblast populations. Informed by combined cell trajectories and pathway analyses, we illustrate that TGFb inhibition in vitro can preserve a more MSC-like phenotype (c) 2022 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Automated summary

Among bone marrow stromal cells, mesenchymal stromal cells (MSCs) are of particular interest due to their support for hematopoiesis, contribution to disease progression, therapy resistance, and leukemic initiation. In this study, cultured bone marrow-derived stromal cells (cBMSCs) were compared with in vivo counterparts on a transcriptome level. The results showed that cultured BMSCs are a homogeneous cell population, independent of isolation method, and more similar to in vivo fibroblast populations. Furthermore, TGFb inhibition in vitro can preserve a more MSC-like phenotype.