Inhibins, activins, and follistatins: Expression of mRNAs and cellular localization in tissues from men with benign prostatic hyperplasia

• Published in: The Prostate 1998-01, Vol.34 (1), p.34-43
• Main Authors: Thomas, Tania Z., Chapman, Susan M., Hong, Wang, Gurusingfhe, Chandan, Mellor, Sally L., Fletcher, Richard, Pedersen, John, Risbridger, Gail P.
• Format: Article
• Language: English
• Subjects: Activin Receptors; Activins; Animals; Biological and medical sciences; BPH; Follistatin; Gene Expression; Glycoproteins - analysis; Glycoproteins - genetics; Humans; immunolocalization; Inhibin-beta Subunits; inhibin-related proteins; Inhibins - analysis; Inhibins - biosynthesis; Inhibins - genetics; Male; Medical sciences; Nephrology. Urinary tract diseases; novel activins; Oligopeptides; Peptides - analysis; Peptides - genetics; Peptides - metabolism; Prostatic Hyperplasia - metabolism; Prostatic Hyperplasia - pathology; Prostatic Secretory Proteins; Rabbits; Rats; Receptors, Growth Factor - analysis; Receptors, Growth Factor - genetics; RNA, Messenger - metabolism; Tumors of the urinary system; Urinary tract. Prostate gland
• ISSN: 0270-4137; 1097-0045
• DOI: 10.1002/(SICI)1097-0045(19980101)34:1<34::AID-PROS5>3.0.CO;2-K

BACKGROUND The transforming growth factor |gb (TGF β) superfamily of growth factors includes activins and inhibins, which have been shown to be present in the rat ventral prostate, and human prostate tumor cell lines, although their localization in benign prostatic hyperplasia (BPH) tissue is currently unknown. METHODS BPH tissues were obtained at surgery, and the mRNA expression for the inhibin α, βA, βB subunits, the putative activin βC subunit, the activin type II receptor (ActRII), and the activin binding protein, follistatin, was determined by reverse transcription polymerase chain reaction (RT‐PCR) and Southern blot analysis. Antibodies specific for α, βA, βB, activin A, and follistatin were used to determine the localization of these proteins in BPH tissue specimens. RESULTS Southern blot analysis confirmed that mRNA for ActRII, βC subunit, and follistatin was present in all biopsy samples assayed. However, α, βA, and βB subunit mRNA expression was variable between patient samples. Immunohistochemistry demonstrated the predominant localization of βA, βB, and activin A proteins to the epithelium of BPH tissues. No immunoreactivity for the inhibin α subunit was detected; follistatin immunoreactivity was localized to the fibroblastic stroma. CONCLUSIONS The compartmentalization of activin subunit proteins to the epithelium, and of follistatin to the stroma, suggests that a paracrine interaction occurs between the activin ligands and follistatin‐binding proteins in BPH tissue. Prostate 34:34–43, 1998. © 1998 Wiley‐Liss, Inc.