A New Subtype of Glomerular Capillary Endothelial Cells Was Found in the Human Glomerular Single-Cell Transcriptome

Background: Kidney endothelial cells from different sites with different phenotypes coexist in three anatomical and functional compartments of the kidney, namely the glomerulus, the cortex and the medulla, supporting specific renal tasks. However, the heterogeneity of glomerular capillary endothelial cells (EC-GCs) is still poorly addressed and not as widely recognized as the heterogeneity of renal medullary and cortical endothelium. Methods: We carried out scRNA-seqand spatial transcription sequencing (ST-seq) of children's kidney tissues near the cortex. Human glomeruli were rapidly enriched and human glomerular cell atlas was successfully constructed. The molecular signatures of the identified human EC-GCs were validated at the protein level. Combined scRNA-seq data from mouse glomeruli and bulk RNA-seq data from human renal disease glomeruli were synthesized and deconvoluted to clarify the alterations of different glomerular cell subtypes in disease. Results: (1) Combined scRNA-seq and ST-seq of human kidney tissues, the human glomerular cell atlas was successfully constructed, which comprehensively demonstrated the molecular features of human glomerular cells. (2) EC-GCs might consist of a group of TOP2A+EC-GCs with proliferative function, a group of EMS1+EC-GCs with high expression of THBS1 and GJA1, a group of THBD+EC-GCs with high expression of PTGS1 and FABP5, and a group of classical EC-GCs. (3) THBD+EC-GCs was associated with shear stress, and the source of differentiation of other cellular subtypes of EC-GCs. And shear stress might be a key factor driving this differentiation. (4) The diversity of human EC-GCs identified in this study is also present in mice. Deconvolutional analysis of bulk RNA-seq of glomeruli in human kidney disease revealed that both cellular proportions and characteristic molecules of glomerular cells are significantly altered in the disease, and that a significant increase in the number of shear stress -associated EC-GCs may be among the characteristic changes. Conclusion: EC-GCs are composed of multiple subtypes of cells with different molecular characteristics, and that shear stress -related THBD+EC-GCs might be the source of the development of EC-GCs. Shear stress -associated molecular features are significantly altered in glomerular diseases, which may be the key pathological molecular features of EC-GCs. Funding: Government Support – Non-U.S.