Direct effects of diethylstilbestrol on the gene expression of the cholesterol side-chain cleavage enzyme (P450scc) in testicular Leydig cells.
OBJECTIVE
To investigate the precise mechanisms underlying the action of estrogenic endocrine disruptors, we evaluated the direct effects of synthetic estrogen diethylstilbestrol (DES) on steroidogenesis in Leydig cells, with particular emphasis on the expression of the cholesterol side-chain cleavage enzyme P450scc. Furthermore, the mechanism underlying the action of DES was compared with that of endogenous estrogen 17beta-estradiol (E2), which has a potency equivalent to that of DES.


METHODS
TTE1 Leydig cells were treated with 5 x 10(-)(8) microM to 5 microM DES or E2 for 24h, and P450scc gene expression and the histone modifications underlying their transcriptional activation were examined using reverse transcription-polymerase chain reaction (RT-PCR) and chromatin immunoprecipitation (ChIP), respectively.


RESULTS
P450scc mRNA expression in the DES-treated and E2-treated cells reduced in inverse proportion to the dose of DES and E2, respectively; however, cAMP stimulation induced a recovery in the expression to a level approximately equal to those in the controls. In the DES-treated cells, ChIP assay revealed histone deacetylation in the P450scc promoter region. Interestingly, E2 did not cause histone deacetylation.


CONCLUSIONS
In the early stages of steroidogenesis, DES and E2 directly induced a reduction in P450scc mRNA expression in inverse proportion to their doses, and treatment with cAMP restored the decreased P450scc mRNA expression. Furthermore, DES can induce alterations in the histone modification of the P450scc gene, and natural estrogen and synthetic estrogenic compounds such as DES may induce reproductive disorders through different molecular mechanisms.
Warita
Katsuhiko
K
Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kagawa, Japan. warita@med.kagawa-u.ac.jp
Mitsuhashi
Tomoko
T
Sugawara
Teruo
T
Tabuchi
Yoshiaki
Y
Tanida
Takashi
T
Wang
Zhi-Yu
ZY
Matsumoto
Yoshiki
Y
Yokoyama
Toshifumi
T
Kitagawa
Hiroshi
H
Miki
Takanori
T
Takeuchi
Yoshiki
Y
Hoshi
Nobuhiko
N
D000107:Acetylation; D000728:Androgens / Q000096:biosynthesis; D000818:Animals; D002460:Cell Line; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics*; D047369:Chromatin Immunoprecipitation; D004054:Diethylstilbestrol / Q000633:toxicity*; D052244:Endocrine Disruptors / Q000633:toxicity*; D004958:Estradiol / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects*; D007985:Leydig Cells / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000728:Androgens; D052244:Endocrine Disruptors; D012333:RNA, Messenger; D004958:Estradiol; D004054:Diethylstilbestrol; D002786:Cholesterol Side-Chain Cleavage Enzyme