Characterization of murine non-hematopoietic bone marrow cells in non-fibrotic, pre-fibrotic and fibrotic conditions

We isolated non-hematopoietic cells from fibrotic and non-fibrotic mouse bone marrow and perfomed scRNAseq on them. We identified 8 different stromal populations. Our analysis revealed two distinct mesenchymal stromal cells (MSC) subsets as pro-fibrotic cells. MSCs were functionally reprogrammed in a stagedependent manner with loss of their progenitor status and initiation of differentiation in the prefibrotic stage and acquisition of a pro-fibrotic and inflammatory phenotype in the fibrotic stage. In parallel, IL-33-expressing myelinating Schwann cell progenitors expanded, likely as a repair mechanism for the previously described neuropathy in MPN. Overall design: We used scRNA 3' RNA sequencing product from 10x Genomics to profile murine non-fibrotic bone marrow as well as bone marrow with Thrombopoietin- and JAK2V617F-induced myelofibrosis