Remodelling landscape of tissue‐engineered bladder with porcine small intestine submucosa using single‐cell RNA sequencing

OBJECTIVE: Bioscaffolds are widely used for tissue engineering, but failed and inconsistent preclinical results have hampered the clinical use of bioscaffolds for tissue engineering. We aimed to construct a cellular remodelling landscape and to identify the key cell subpopulations and important genes driving bladder remodelling. METHODS: Twenty‐four reconstructed mouse bladders using porcine small intestinal submucosa (PSIS) were harvested at 1, 3, and 6 weeks to perform single‐cell RNA sequencing. Cell types were identified and their differentially expressed genes (DEGs) at each stage were used for functional analysis. Immunofluorescence was used to validate the specific cell type. RESULTS: The remodelling landscape included 13 cell types. Among them, fibroblasts, smooth muscle cells (SMCs), endothelial cells, and macrophages had the most communications with other cells. In the process of regeneration, DEGs of fibroblasts at 1, 3, and 6 weeks were mainly involved in wound healing, extracellular matrix organization, and regulation of development growth, respectively. Among these cells, Saa3(+) fibroblasts might mediate tissue remodelling. The DEGs of SMCs at 1, 3, and 6 weeks were mainly involved in the inflammatory response, muscle cell proliferation, and mesenchyme development, respectively. Moreover, we found that Notch3(+) SMCs potentially modulated contractility. From 1 to 6 weeks, synchronous development of endothelial cells was observed by trajectory analysis. CONCLUSIONS: A remoulding landscape was successfully constructed and findings might help surficial modifications of PSIS and find a better alternative. However, more in vivo and in vitro studies are needed to further validate these results.