Transforming growth factor-beta 1 post-transcriptionally inhibits mouse growth hormone releasing factor secretion in placenta.
The aim of this study was to investigate whether TGF-beta 1 regulates mouse GHRF secretion by primary cultures of placental cells from day 12 of pregnancy. Ten ng/ml TGF-beta 1 significantly inhibited mouse GHRF secretion by the third day of culture. The lowest concentration of TGF-beta 1 that significantly inhibited mouse GHRF secretion was 1 ng/ml. The inhibitory effect of TGF-beta 1 on mouse GHRF secretion was completely eliminated by addition of an anti-TGF-beta 1 antibody. Steady-state levels of mouse GHRF mRNA as assessed by Northern analysis was not reduced by incubation of placental cells from day 12 of pregnancy with 10 ng/ml TGF-beta 1 for 5 days. Both placenta and decidua expressed TGF-beta 1 mRNA, and the level of TGF-beta 1 mRNA in decidua increased during gestation while the level of TGF-beta 1 mRNA was constant throughout gestation. These findings suggest that TGF-beta 1 is one of the potent regulators of mouse GHRF secretion and that TGF-beta 1 regulates mouse GHRF secretion in an autocrine or paracrine manner in the mouse placenta in vivo.
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
M
M
Yamaguchi
H
H
Endo
T
T
Maeda
M
M
Tahara
M
M
Ono
N
N
Miki
A
A
Miyake
D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D003656:Decidua / Q000187:drug effects / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D005865:Gestational Age; D013007:Growth Hormone-Releasing Hormone / Q000096:biosynthesis* / Q000378:metabolism; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D010920:Placenta / Q000187:drug effects / Q000378:metabolism*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D013007:Growth Hormone-Releasing Hormone; D007930:Leucine