Differential expression of steroidogenic factor-1 and FTF/LRH-1 in the rodent ovary.
Steroidogenic factor-1 (SF-1) (NR5A1) is an orphan nuclear receptor that plays a premier role in ovarian organogenesis. Recent studies document mRNA expression of the structurally related factor NR5A2 (FTF, LRH-1, SF-2) in the adult ovary and more specifically in granulosa cells and luteal cells but not theca cells. Conversely, SF-1 was shown to be expressed at higher levels in theca/interstitial cells. These latter observations raised the possibility that FTF/LRH-1 may control target gene expression in granulosa cells of developing follicles. Using quantitative PCR our results show that FTF/LRH-1 message is expressed at higher levels in the ovary than in liver or other tissues analyzed. We show by in situ hybridization and LacZ expression in ovaries of transgenic mice bearing an FTF-promoter-LacZ fusion gene that FTF/LRH-1 is selectively expressed in granulosa cells of rat and mouse ovaries and is not present in theca cells or interstitial cells. However, by a variety of approaches, we showed that SF-1 mRNA and protein are expressed in greater amounts than FTF/LRH-1 in granulosa cells of follicles at all stages of development. Expression of SF-1 mRNA and protein in granulosa cells was verified by in situ hybridization, immunohistochemistry of ovarian sections, and immunocytochemistry of cultured rat granulosa cells. The significance of SF-1 in regulating target gene activation was supported by EMSA. An abundant granulosa cell protein binding to the SF-1-binding motif (CCAAGGTCA) present in the aromatase promoter and an FTF/LRH-1 motif (TGTCCTTGAACA) in the alpha-fetoprotein promoter was supershifted by two SF-1-specific antibodies but not by an FTF antibody. Conversely, with the same probes, a less abundant protein/DNA complex present in liver and ovarian cell extracts was shifted by an FTF antibody but not by the SF-1 antibodies. SF-1 and FTF/LRH-1 were differentially regulated in vivo by estradiol, FSH and prolactin. Collectively these data indicate that granulosa cells of small and preovulatory follicles express both SF-1 and FTF/LRH-1 and that each orphan receptor may regulate target gene expression in these cells.
Falender
Allison E
AE
Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
Lanz
Rainer
R
Malenfant
Daniel
D
Belanger
Luc
L
Richards
JoAnne S
JS
D000818:Animals; D001141:Aromatase / Q000235:genetics; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics*; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D051717:Fushi Tarazu Transcription Factors; D005786:Gene Expression Regulation / Q000187:drug effects; D006107:Granulosa Cells / Q000737:chemistry; D018398:Homeodomain Proteins; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008099:Liver / Q000737:chemistry; D008184:Luteal Cells / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D010053:Ovary / Q000737:chemistry*; D011388:Prolactin / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis / Q000172:deficiency / Q000235:genetics*; D011993:Recombinant Fusion Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054339:Steroidogenic Factor 1; D013799:Theca Cells / Q000737:chemistry; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics*; D015533:Transcriptional Activation; D000509:alpha-Fetoproteins / Q000235:genetics
D004268:DNA-Binding Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; C417002:NR5A2 protein, rat; C431936:Nr5a2 protein, mouse; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; D000509:alpha-Fetoproteins; C515058:steroidogenic factor 1, mouse; C515060:steroidogenic factor 1, rat; D004958:Estradiol; D011388:Prolactin; D005640:Follicle Stimulating Hormone; D001141:Aromatase