Inhibin/activin subunit mRNA expression in human granulosa-luteal cells.
We studied the expression of inhibin/activin subunit mRNAs in granulosa-luteal cells of preovulatory ovarian follicles obtained from women undergoing in vitro fertilization, and in corpus luteum tissue samples of early pregnancy. Northern analysis of granulosa-luteal cell and corpus luteum RNA with single-stranded cDNA or cRNA probes revealed an 1.6-kb mRNA for the alpha subunit and about 6.0-, 4.0-, 2.8-, and 1.7-kb transcripts for the beta A subunit. No clear hybridization signal for the beta B subunit could be detected. The relative expression levels of alpha and beta A subunit mRNAs were determined at 2-day intervals in granulosa-luteal cells cultured for 5 to 11 days. The levels of alpha subunit mRNAs declined steadily with increasing culture age, whereas those of beta A remained unchanged. Reverse transcription-polymerase chain reaction analysis with 35 amplification cycles confirmed the expression of alpha and beta A subunit mRNAs in cultured granulosa-luteal cells. The beta B transcripts were also weakly detectable by this sensitive assay. In situ hybridization of human early pregnancy corpus luteum revealed intense hybridization with the alpha cRNA probe and a weaker signal for the beta A subunit in the granulosa cell compartment. We conclude that: (1) the inhibin alpha and beta A subunits (and to a lesser extent beta B) are expressed in cultured human granulosa-luteal cells; (2) during extended culture periods the alpha/beta A mRNA expression ratio decreases; and that (3) the alpha and beta A subunit mRNA expression is observed in the granulosa cell compartment of early pregnancy corpora lutea.
Erämaa
M
M
Department of Bacteriology and Immunology, University of Helsinki, Finland.
Heikinheimo
K
K
Tuuri
T
T
Hildén
K
K
Ritvos
O
O
D028341:Activins; D015152:Blotting, Northern; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000166:cytology / Q000378:metabolism*; D005260:Female; D005307:Fertilization in Vitro; D015870:Gene Expression; D006107:Granulosa Cells / Q000378:metabolism*; D006801:Humans; D017403:In Situ Hybridization; D007265:Inhibins / Q000096:biosynthesis* / Q000235:genetics; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics
D012333:RNA, Messenger; D028341:Activins; D007265:Inhibins