Sertoli Cell‐Derived Extracellular Vesicles Orchestrate Cadmium‐Induced Testicular Inflammation and Fibrosis

ABSTRACT Cadmium (Cd) is a widespread environmental toxicant that impairs male reproductive health, though its testicular toxicity mechanisms remain incompletely defined. Combining single‐cell RNA sequencing with functional assays, we identified a novel intercellular communication pathway mediated by Sertoli cell‐derived extracellular vesicles (EVs) in Cd‐induced testicular injury. In mice, Cd exposure caused testicular atrophy, spermatogenesis disruption, and fibrosis. Multi‐omics analyses revealed activation of multiple programmed cell death pathways, including apoptosis, necroptosis, pyroptosis, and ferroptosis. Single‐cell RNA sequencing (scRNA‐seq) demonstrated testicular cellular remodeling featuring Sertoli cell depletion and fibroblast expansion. Mechanistically, Cd triggered multi‐modal programmed cell death (PCD) in Sertoli cells, promoting EV release enriched with damage‐associated molecular patterns (DAMPs) and mitochondrial components. These EVs were internalized by testicular macrophages, activating the TLR4/NF‐κB pathway and inducing a pro‐inflammatory phenotype. Consequently, activated macrophages stimulated fibroblast‐mediated fibrosis via TGF‐β/Smad signaling. These findings elucidate a Sertoli cell‐EV‐macrophage‐fibroblast axis in Cd‐induced testicular damage, offering new insights into environmental toxicant‐induced male infertility and potential therapeutic targets.