Single-cell transcriptomics of human embryos identifies multiple sympathoblast lineages with potential implications for neuroblastoma origin.

Abstract

Characterization of the progression of cellular states during human embryogenesis can provide insights into the origin of pediatric diseases. We examined the transcriptional states of neural crest- and mesoderm-derived lineages differentiating into adrenal glands, kidneys, endothelium, and hematopoietic tissue between post-conception weeks 6 and 14 of human development. Our results reveal transitions connecting intermediate mesoderm and progenitors of organ primordia, the hematopoietic system, and endothelial subtypes. Unexpectedly, by using a combination of single cell transcriptomics and lineage tracing, we found that intra-adrenal sympathoblasts at that stage are directly derived from the nerve-associated Schwann cell precursors similarly to local chromaffin cells, whereas the majority of extra-adrenal sympathoblasts arise from the migratory neural crest. In humans, this process persists during several weeks of development within the large intra-adrenal ganglia-like structures, which may also serve as reservoirs of originating cells in neuroblastoma.