Single‐cell RNA‐sequencing technology demonstrates the heterogeneity between aged prostate peripheral and transitional zone

BACKGROUND: Identifying cellular and functional heterogeneity within aged prostate is critical for understanding the spatial distribution of prostate diseases. METHODS: Aged human prostate peripheral zone (PZ) and transitional zone (TZ) tissues were used for single‐cell RNA‐sequencing. Results were validated by immunofluorescence staining. RESULTS: We found that club/hillock epithelial cells, compared with other epithelial cells, had significantly higher NOTCH signaling activity and expressed higher levels of neuro‐stems but lower androgen‐related genes. These cells were primarily found in the TZ and provided a stem‐like niche around the proximal prostate ducts. Significant heterogeneity was observed in the aged luminal population. A novel TFF3+ luminal subtype with elevated MYC and E2F pathway activities was observed, primarily in the PZ. Further analysis revealed that epithelial cells in the TZ had higher levels of stem‐ and inflammation‐related pathway activities but lower androgen/lineage‐related pathway activities than those in the PZ. Notably, the activation of MYC, E2F and DNA repair pathways significantly increased in PZ luminal cells. In the immune landscape, we found that the immune microenvironment in the TZ is more complex and disordered with more infiltration of NK and Treg cells. CD8 T cell and macrophage in the TZ exhibit both inflammation activation and suppression phenotypes. In the stroma, the TZ had a higher fibroblast density, and fibroblasts in the TZ exhibited stronger transcriptome activity in immunity and proliferation. Ligand–receptor interaction analysis revealed that fibroblasts could contribute to a NOTCH signaling niche for club/hillock cells in the TZ and balance the prostate immune microenvironment. The activation of stem properties, inflammatory infiltration and loss of androgen/lineage activity are prominent features distinguishing the TZ from PZ. CONCLUSIONS: Our study explains the heterogeneity between the TZ and PZ of aged prostate, which may help understand the spatial distribution of prostate diseases and establish a foundation for novel target discovery.