Effect of transforming growth factor beta on the expression of luteinizing hormone receptor in cultured rat granulosa cells.
The present study was undertaken in order to identify the mechanism underlying the effect of transforming growth factor-beta (TGFbeta) on LH receptor (LH-R) expression in rat granulosa cells. Treatment with FSH produced a substantial increase in LH-R mRNA level, and concurrent treatment with increasing concentrations of TGFbeta brought about dose-dependent increases in FSH-induced LH receptor mRNA. TGFbeta, either alone or in combination with FSH, did not affect intracellular cAMP levels. We then investigated whether the effect of TGFbeta and FSH on LH-R mRNA levels results in increased transcription and/or altered mRNA stability. To determine whether the LH receptor 5'-flanking region plays a role in directing LH receptor mRNA expression, the proximal area of the LH receptor 5'-flanking regions were inserted into an expression vector, pGL-Basic, which contains luciferase as the receptor gene, and the resulting plasmids were transiently transfected into rat granulosa cells. FSH (30 ng/ml) significantly enhanced the activity of 1389 base pairs of the LH receptor 5'-flanking region, but treatment with TGFbeta did not significantly influence the activity induced by FSH. On the other hand, the decay curves for LH-R mRNA transcript in primary granulosa cells showed a significant increase in half-life after the addition of TGFbeta.
Department of Obstetrics and Gynecology, School of Medicine, Gunma University, Maebashi, Gunma 371-8511, Japan.
Kyoko
K
Inoue
Kazuto
K
Nakamura
Kazuko
K
Abe
Takashi
T
Hirakawa
Megumi
M
Tsuchiya
Hiroko
H
Matsuda
Kaoru
K
Miyamoto
Takashi
T
Minegishi
D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D004054:Diethylstilbestrol / Q000494:pharmacology; D004968:Estrogens, Non-Steroidal / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D005822:Genetic Vectors / Q000235:genetics; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D011974:Receptors, LH / Q000096:biosynthesis*; D014158:Transcription, Genetic / Q000235:genetics; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D004968:Estrogens, Non-Steroidal; D012333:RNA, Messenger; D011974:Receptors, LH; D016212:Transforming Growth Factor beta; D004054:Diethylstilbestrol; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP