Poster abstracts

Poster number 144 submitted by Surbhi Sona

Single-Cell and Spatial Mapping Identify Cell Types and Signaling Networks in the Human Ureter with Regards to its Regenerative Potential

Surbhi Sona (Genomic Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland,, OH 44195, USA), Emily E. Fink, Matthew Bradley, Angela H. Ting (Genomic Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA), Pierre-Emmanuel Desprez, Mohamed Eltemamy, Georges-Pascal Haber (Glickman Urological & Kidney Institute, Cleveland Clinic, Cleveland, OH 44195, USA), Uyen Tran, Hong Qiu, Madison Wolkov, Oliver Wessely,Byron H. Lee (Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA), Marlo Nicolas (Pathology & Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH 44195, USA ), Booki Min (Department of Microbiology and Immunology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA)

Developmental defects or damage due to high levels of inflammation or radiation therapy in cancer can often lead to ureteral pathologies. Ureter reconstruction surgeries utilizing tissue engineering remain a lucrative treatment avenue in such scenarios. Here, we utilized scRNA-seq data generated from 10 normal human ureters to understand the cellular architecture and signaling pathways that contribute to the regenerative potential of the ureter. We identified several subtypes of the 3 major cell types in the urothelium, which is functionally the most important tissue layer in ureter. Among the urothelial cell types, we identified Sonic Hedgehog (SHH)-expressing basal cells that are most likely the stem cell population in the ureter - setting these cells as the root in the trajectory analysis using monocle3, accurately predict the general differentiation trajectory across the different urothelial cells. This was experimentally validated, using ureter organoid generation assay, the rate of which positively correlated with SHH expression. Further, the spatial transcriptomics analysis on this cohort’s ureter sections revealed that peri-urothelial fibroblasts reside right next to the urothelium. We then utilized, the Cellphonedb analysis to query the potential cellular signaling between basal cells and peri-urothelial fibroblasts, which included WNT, BMP, EGF and TGF pathways (likelihood test, p value <0.00001). We observed WNT4 signaling from these fibroblasts to frizzled class (FZD) receptors on all basal cell population, including SHH-expressing basal cells. This is synonymous to a previous mice study that suggested an important role of interaction between WNT7B and FZD1 working in parallel to SHH signaling. In conclusion, our study describes the cellular composition of the human ureter at a single cell resolution, identifies a potential SHH-expressing basal stem cell subpopulation and offers useful insights to the regenerative potential of the human ureter which could contribute to tissue engineering endeavors for the treatment of ureteral pathologies.

Keywords: Human ureter, Single-cell RNA sequencing, sonic hedgehog