GSE135442
RNA sequencing of mouse glomerular endothelial cells and implications of their heterogeneity in Alport syndrome
Background: Recent transcriptomic studies of total glomerular and isolated glomerular endothelial cells (GEC) provide much needed insight into the potential associations between expression of specific genes and dysfunctional endothelium in the development of diabetic kidney disease. Similarly, many studies on Alport syndrome (AS) mice, including our own, suggest that damage to GEC can contribute to disease progression. However, the underlying cellular and molecular pathways and associated transcriptional identity of the cells remain either limited or non-existent. Methods: We used a model of endothelial-specific tdTomato reporter mouse for the feasibility of isolating the GEC from kidneys of WT and AS mice. To generate a snapshot of GEC specific transcriptional profiles and to elucidate gene expression changes in AS, we performed transcriptome-wide RNA-seq analysis of GEC from AS-TektdT mice and control WT-TektdT mice at 4-month of age. Results: We identified two subpopulations of GEC (dimtdT and brighttdT) based on the fluorescence intensity of the TektdT signal. Gene expression analysis showed vast heterogeneity in the two subpopulations, including in the expression of endothelial specific genes. In AS, dimtdT and brighttdT GEC had remarkably heterogeneous profiles in matrix associated genes (Svep1, Itgß6), metabolic activity (ApoM, Pgc1a) and immune modulation (Apelin, Icam1) compared to WT. Additionally, we confirmed the expression data of these genes in biopsy samples from AS and FSGS patients. Conclusions: Our findings suggest the presence of two subpopulations of GEC that develop distinct responses in metabolic and inflammatory immune activity in AS. In depth understanding of the pathologic role of GEC in the progression of AS could lead to novel targets for intervention. Overall design: Gene expression profiles of glomerular endothelial cells derived from wild type and Alport syndrome mice at 4 month of age were generated by RNA sequencing.