Transforming growth factor-beta 2 heterozygous mutant mice exhibit Cowpers gland hyperplasia and cystic dilations of the gland ducts (Cowpers syringoceles)

摘要

Analyses of mutant mice with a deletion for the transforming growth factor beta 2 (Tgfβ2) gene revealed cysts in the perineal/scrotal region of male mice. We present evidence from in situ, light and electron microscopy that the cysts observed in Tgfβ2^+/− heterozygous mice males derive from Cowper's glandtissue. The Cowper's glands of Tgfβ2^+/− heterozygous mutant mice display all steps of glandular hyperplasiaand cystic dilation. TGF-β isoforms and TGF-β receptor (TβR-II) were localized immunocytochemicallyin sections of Cowper's glands. TGF-ββ2 and TGF-β3 were located predominantly inmyoepithelial cells of the Cowper's gland whereas the TβRII was found in the plasma membrane of the acinar cells. TUNEL-assays revealed that apoptotic cell death is significantly reduced in Cowper's glands of Tgfβ2^+/− heterozygous mutant mice. The fact that Tgfβ2^+/− heterozygous mutant mice exhibit hyperplasia of Cowper's gland epithelium and Cowper's gland cysts suggests a disturbance of epithelial–stromal interaction mostlikely due to reduced TGF-β2 level, accompanied by a significant decrease in apoptosis.