In-vivo differentiation of adult hematopoietic stem cells from a single-cell point of view

Purpose of review Although hematopoietic stem cell (HSC) function has long been studied by transplantation assays, this does not reflect what HSCs actually do in their native context. Here, we review recent technologic advances that facilitate the study of HSCs in their native context focusing on inducible HSC-specific lineage tracing and inference of hematopoietic trajectories through single-cell RNA sequencing (scRNA-Seq). Recent findings Lineage tracing of HSCs at the population level using multiple systems has suggested that HSCs make a major contribution to steady-state hematopoiesis. Although several genetic systems and novel methods for lineage tracing individual hematopoietic clones have been described, the technology for tracking these cellular barcodes (in particular mutations or insertion sites) is still in its infancy. Thus, lineage tracing of HSC clones in the adult bone marrow remains elusive. Static snapshots of scRNA-Seq of hematopoietic populations have captured the heterogeneity of transcriptional profiles of HSCs and progenitors, with some cells displaying a unilineage signature as well as others with bi or multipotent lineage profiles. Kinetic analysis using HSC-specific lineage tracing combined with scRNA-Seq confirmed this heterogeneity of progenitor populations and revealed a rapid and early emergence of megakaryocytic progeny, followed by erythroid and myeloid lineages, whereas lymphoid differentiation emerged last. Summary New approaches to st...
Source: Current Opinion in Hematology - Category: Hematology Tags: HEMATOPOIESIS: Edited by Hal E. Broxmeyer and Maegan L. Capitano Source Type: research