Single-Cell RNA Sequencing Reveals Cellular Heterogeneity and Microenvironmental Remodeling in Human Ureteral Scar Stricture Tissue.

Abstract

Purpose: This study aimed to construct a comprehensive single-cell transcriptomic atlas of human ureteral scar stricture tissue using single-cell RNA sequencing (scRNA-seq), to uncover cellular heterogeneity, subpopulation dynamics, and intercellular communication networks.

Methods: Ureteral tissues were collected from three normal controls (CTR) and three patients with ureteral scar stricture (US). Single-cell suspensions were prepared using the MobiNova-100 platform and sequenced on the Illumina NovaSeq 6000 system. Data were analyzed using Seurat, Harmony, Monocle2 (for pseudotime trajectory analysis), CellChat (for cell-cell communication), and SCP (for GO/KEGG enrichment). Key findings were validated by multiplex immunofluorescence (IF) and immunohistochemistry (IHC).

Results: Eleven major cell types were identified, including epithelial, stromal, endothelial, and immune cells, each comprising distinct subpopulations. Compared to CTR tissues, US tissues exhibited an increased proportion of S100A8⁺ and MT1E⁺ basal epithelial cells with pro-inflammatory characteristics. Fibroblasts displayed substantial heterogeneity, with expansion of inflammatory fibroblasts and smooth muscle cell subsets. Endothelial cells (ECs) showed upregulated inflammatory and antigen presentation pathways. Macrophages exhibited mixed M1/M2 polarization, with enrichment of APOE⁺ and APOBEC3A⁺ subsets. Additionally, Th17, Treg, and CD8⁺ T cell populations were elevated. Cell-cell communication analysis revealed enhanced signaling among fibroblasts, ECs, and immune subsets, particularly via PERIOSTIN, collagen, and laminin pathways.

Conclusion: This study presents the first high-resolution single-cell atlas of ureteral scar stricture tissue, revealing profound cellular heterogeneity and remodeling of the immune-stromal-epithelial landscape. The findings also highlight intensified intercellular communication within the fibrotic microenvironment, offering novel insights into disease pathogenesis and potential therapeutic targets.