RT Journal Article
SR Electronic
T1 Transcriptional Characterisation of Human Lung Cells Identifies Novel Mesenchymal Lineage Markers
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 1900746
DO 10.1183/13993003.00746-2019
A1 Soula Danopoulos
A1 Soumyaroop Bhattacharya
A1 Thomas J. Mariani
A1 Denise Al Alam
YR 2019
UL http://erj.ersjournals.com/content/early/2019/09/25/13993003.00746-2019.abstract
AB Rationale The lung mesenchyme gives rise to multiple distinct lineages of cells in the mature respiratory system, including smooth muscle cells (SMCs) of the airway and vasculature. However, a thorough understanding of the specification and mesenchymal cell diversity in the human lung is lacking.Methods We completed single cell RNA sequencing analysis of fetal human lung tissues. Canonical correlation analysis, clustering, cluster marker gene identification and tSNE representation was performed in Seurat. Cell populations were annotated using Toppfun. Immunohistochemistry and in situ hybridisation were used to validate spatio-temporal gene expression patterns for key marker genes.Results We identified molecularly distinct populations representing “committed” fetal human lung endothelial cells, pericytes, and smooth muscle cells (SMCs). Early endothelial lineages expressed “classic” endothelial cell markers (PECAM, CLND5) while pericytes expressed PDGFRβ, THY1 and basement membrane molecules (COL4, laminin, proteoglycans). We observed a large population of “nonspecific” human lung mesenchymal progenitor cells characterised by expression of COL1 and multiple elastin fiber genes (ELN, MFAP2, FBN1). We closely characterised diversity of mesenchymal lineages defined by ACTA2 expression. Two cell populations, with the highest levels of ACTA2 transcriptional activity, expressed unique sets of markers associated with airway- or vascular- SMCs. Spatio-temporal analysis of these marker genes confirmed early and persistent spatial specification of airway (HHIP, MYLK, IGF1) and vascular (NTRK3, MEF2C) SMCs in the developing human lung.Conclusion Our data suggest that specification of distinct airway and vascular SMC phenotypes are established early in development and can be identified using the markers we provide.FootnotesThis manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.Conflict of interest: Dr. Danopoulos has nothing to disclose.Conflict of interest: Dr. Bhattacharya has nothing to disclose.Conflict of interest: Dr. Mariani has nothing to disclose.Conflict of interest: Dr. Al Alam has nothing to disclose.