Prostatic ductal system in rats: tissue-specific expression and regional variation in stromal distribution of transforming growth factor-beta 1.
BACKGROUND
Regional variations in stromal-epithelial interactions, mediated through soluble growth factors, may be responsible for differences in epithelial growth and death observed between regions of the rat prostatic ductal system. Since transforming growth factor-beta 1 (TGF-beta 1) can induce prostatic epithelial cell death in vitro and in vivo, we examined the localization and production of TGF-beta 1 with respect to the functional regions of the rat prostatic ductal system.


METHODS
The distribution of TGF-beta 1 in the rat ventral prostate was examined by immunohistochemistry. Cell type-specific expression of TGF-beta 1 was determined using RT-PCR analysis of prostate epithelial and stromal cell fractions separated by Percoll gradient centrifugation.


RESULTS
Immunohistochemical staining of normal prostate revealed regional variations in stromal TGF-beta 1 protein, which was most abundant in the stroma surrounding the degenerative proximal ducts. TGF-beta 1 staining was also tightly associated with the prostatic smooth muscle. Results of RT-PCR experiments confirmed the major source of TGF-beta 1 mRNA in normal rat prostate to be the stroma, with lesser expression by the epithelium.


CONCLUSIONS
Stromal TGF-beta 1 was associated with cell death in the adjacent epithelial cell compartment in the prostatic ductal system, and alpha-smooth muscle actin-positive stromal cells may play a negative growth-regulatory role in the rat ventral prostate through production of TGF-beta 1.
Nemeth
J A
JA
Department of Urology, Northwestern University Medical School, Chicago, Illinois 60611, USA.
Sensibar
J A
JA
White
R R
RR
Zelner
D J
DJ
Kim
I Y
IY
Lee
C
C
D000818:Animals; D015153:Blotting, Western; D002469:Cell Separation; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011467:Prostate / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017154:Stromal Cells / Q000378:metabolism; D014018:Tissue Distribution; D014158:Transcription, Genetic; D016212:Transforming Growth Factor beta / Q000378:metabolism*
D016212:Transforming Growth Factor beta