Changes in steroid receptors and proteoglycan expression in the guinea pig prostate stroma during puberty and hormone manipulation.

Background: Proteoglycans are structural and informational molecules important during embryogenesis and organ maturation. Maturation of the prostate is influenced by androgens and estrogens, but changes in the relative spatiotemporal expression of steroid receptors and proteoglycans during hormonal change are unexplored.

Methods: Guinea pig prostate was used to define hormone-induced changes in the expression of androgen (AR) and estrogen (ER(alpha)) receptors, chondroitin sulfate (CS) glycosaminoglycan and core proteins of versican and syndecan-1. Tissue locations of AR, ER(alpha), CS and the proteoglycans versican and syndecan-1 were determined by immunohistochemistry. Cellular content of ER(alpha) and syndecan-1 was assessed visually. Versican, CS56 epitope, and AR were quantified by image analysis.

Results: AR expression within prostate epithelial and stromal cell nuclei decreased following castration and increased following treatment of castrate animals with dihydrotestosterone (DHT). ER(alpha) expression was restricted to prostate stromal cell nuclei and decreased during puberty, and following treatment of castrate animals with DHT. Versican was present in periacinar stroma immediately peripheral to basal epithelial cells, fibromuscular stromal tissue bands surrounding acinar units, and loose fibrovascular connective tissue interspersed between individual acini. Versican and native CS expression decreased (>10-fold) in periacinar stroma during puberty and following administration of DHT to castrated animals. Expression of syndecan-1 was restricted to fibromuscular cells of prostate stroma, and remained constant during puberty and hormone manipulation.

Conclusions: ER(alpha), versican core protein and CS side chain epitopes are negatively regulated in prostate stromal tissue by DHT, whilst AR levels are positively regulated.