Regulation of catechol O-methyltransferase expression in granulosa cells: a potential role for follicular arrest in polycystic ovary syndrome.
OBJECTIVE
To investigate the regulation of catechol O-methyltransferase (COMT) expression in granulosa cells and assess potential effects of 2-methoxyestradiol (2-ME2) and COMT inhibitors on granulosa cell steroidogenesis and proliferation.


METHODS
Controlled experimental study in an academic research laboratory.


METHODS
JC410 porcine and HGL5 human granulosa cell lines were used for in vitro experiments. Effects of 2-ME2 and COMT inhibitor treatment on DNA proliferation and steroidogenesis were assessed by using Hoechst dye and p450SCC-luciferase reporter assays. Effects of dihydrotestosterone (DHT), insulin, and all-trans retinoic acid (ATRA) on COMT messenger RNA expression were investigated by using COMTP1 promoter-luciferase reporter and Northern blot.


METHODS
Granulosa cell steroidogenesis and proliferation following COMP inhibitor and 2-ME2 treatment. Regulation of COMT expression with DHT, insulin, and ATRA.


RESULTS
2-Methoxyestradiol had a dual effect on granulosa cell proliferation and p450SCC- luciferase activity; low doses were stimulatory and high doses were inhibitory. Catechol O-methyltransferase inhibitor was associated with up to a 65% increase in JC410 cell number and a maximal 5.6-fold increase in p450SCC-luciferase activity at 20 micromol/L. Dihydrotestosterone, insulin, and ATRA all induced a dose-dependent increase in COMTP1-luciferase transactivation, as well as up-regulated COMT messenger RNA expression in granulosa cells.


CONCLUSIONS
Catechol O-methyltransferase expression in granulosa cells was up-regulated by insulin, DHT, and ATRA. Catechol O-methyltransferase product, 2-ME2, decreased, whereas COMT inhibitor increased granulosa cell proliferation and steroidogenesis. These data suggest that COMT overexpression with subsequent increased level of 2-ME2 may lead to ovulatory dysfunction.
Salih
Sana M
SM
Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas 77555-0587, USA.
Jamaluddin
Mohammad
M
Salama
Salama A
SA
Fadl
Amin A
AA
Nagamani
Manubai
M
Al-Hendy
Ayman
A
D000077584:2-Methoxyestradiol; D000818:Animals; D002394:Catechol O-Methyltransferase / Q000235:genetics* / Q000378:metabolism; D065098:Catechol O-Methyltransferase Inhibitors; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D013196:Dihydrotestosterone / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006107:Granulosa Cells / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D006080:Ovarian Follicle / Q000502:physiology*; D010060:Ovulation / Q000235:genetics; D011085:Polycystic Ovary Syndrome / Q000209:etiology* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013256:Steroids / Q000096:biosynthesis; D013552:Swine; D014212:Tretinoin / Q000494:pharmacology
D065098:Catechol O-Methyltransferase Inhibitors; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D013256:Steroids; D013196:Dihydrotestosterone; D004958:Estradiol; D014212:Tretinoin; D000077584:2-Methoxyestradiol; D002394:Catechol O-Methyltransferase