Osteocyte exosomes accelerate benign prostatic hyperplasia development

Benign prostatic hyperplasia (BPH) is one of the most common diseases in elderly men. BPH patients exhibit an increased risk of vertebral and hip fractures, which are most attributable to pre-existing osteoporosis. However, the relationship between BPH and osteoporosis is still unknown. Here we found that osteocytes, the most abundant bone cells, promoted BPH development by secreting exosomes. In vitro, osteocyte exosomes (OCY-Exo) directly promoted cell proliferation of a prostate epithelial cell line BPH-1 and a macrophage cell line RAW264.7, OCY-Exo also stimulated macrophage-induced proliferation of BPH-1 cells. In vivo, intramedullary injection of OCY-Exo accumulated in prostate. Intravenous administration of OCY-Exo exacerbated testosterone-induced BPH in C57BL/6J mice. Our study uncovers the role of OCY-Exo as a stimulator of BPH, suggesting a novel mechanism in bone-prostate communication.