Apoptotic cell clearance triggers epithelial fate reprogramming during prostate regression.

Androgen deprivation induces extensive tissue remodelling in the prostate, characterized by epithelial cell attrition and acquisition of a progenitor-like state in residual luminal epithelial cells. The mechanisms driving differentiated epithelial cells toward a progenitor fate remain unclear. Here, we identify that prostate regression is mediated by the engulfment of apoptotic neighbours by epithelial cells and that efferocytosis promotes acquisition of a progenitor-like state. We show that epithelial cells are the predominant phagocytes during regression, engaging in temporally coordinated waves of apoptotic cell clearance. This process is accompanied by marked metabolic reprogramming, including increased aerobic glycolysis and lactate production. This coincides with enhanced histone lysine-lactylation at promoters of genes involved in autophagy, apoptosis regulation, and luminal progenitor identity. Blockade of efferocytosis in vivo via epithelial-specific expression of the dominant negative phosphatidylserine binding protein MFGE8-D89E impaired prostate regression and compromised the induction of the luminal progenitor marker Tacstd2. These findings reveal that epithelial efferocytosis is an essential mechanism that couples cell clearance and epithelial plasticity. This work establishes epithelial efferocytosis as a determinant of cell state transitions in the prostate, with implications for a direct role in castration-resistant prostate cancer and other regenerative or remodelling processes.