Presentation Title: Proximal Tubular S3 Cells Expressing Angiotensinogen Localize to the Outer Stripe of the Outer Medulla
Author Name(s): Danielle Janosevic
Abstract: “The S3 segments of proximal tubules (PT) are observed in the cortex and outer stripe of the outer medulla (OS-OM). Using single cell RNA sequencing (scRNAseq), we and others have identified a unique S3 population, referred to as S3-Type 2 (S3T2, Figure a). S3T2 cells uniquely express Rnf24 and Slc22a7, in addition to other S3 markers. We combined spatial transcriptomics (SpT) and scRNAseq to localize this novel S3T2 cell population in the murine kidney.
SpT was performed on OCT frozen murine kidney sections and images collected with Keyence microscope. RNA was isolated from tissue, sequenced, and clustering performed. To increase resolution, we combined scRNAseq data with SpT.
Combining scRNAseq with SpT increased spatial resolution from 7 clusters to 15 unique cell clusters on the tissue section. While regular S3 cells localized to the cortex, S3T2 cells localized specifically to the OS-OM (Fig. b). In addition to Rnf24 and Slc22a7, S3T2 cells showed strong expression of angiotensinogen (Agt, Fig. c), possibly indicating a role in the renin-angiotensin system. smFISH of Agt and Aqp1 confirmed these results (Fig. d).
Combining scRNAseq and SpT affords greater resolution in the spatial layout of renal cell populations and provides novel insights into understanding cellular microenvironments.