title: Expression of TGF-beta superfamily growth factors, their receptors, the associated SMADs and antagonists in five isolated size-matched populations of pre-antral follicles from normal human ovaries.
abstract: In mammals, members of the transforming growth factor-beta (TGF-β) superfamily are known to have key roles in the regulation of follicular growth and development. The aim of the study was to evaluate the expression of TGF-β superfamily growth factors, their receptors, downstream SMAD signalling molecules and TGF-β/bone morphogenetic protein (BMP) antagonists during early human folliculogenesis. Human pre-antral follicles were enzymatically isolated from surplus ovarian tissue obtained from women having ovarian cortical tissue frozen for fertility preservation. A total of 348 human pre-antral follicles, ranging from 40 to 200 µm in diameter, were isolated from ovarian tissue obtained from 15 women, aged 24-34 years. Isolated pre-antral follicles were grouped according to diameter in five size-matched populations spanning the primordial, primary and secondary stage follicles and analysed by whole-genome microarray analysis. Selected proteins/genes were analysed by immunocytochemistry and quantitative RT-PCR. TGF-β superfamily genes with overall highest mRNA expressions levels included growth differentiation factors 9 (GDF9), BMP15, BMP6, BMP-receptor-2 (BMPR2), anti-Müllerian hormone receptor 2 (AMHR2), TGFβR3, inhibin-α (INHA) and intracellular SMAD3 and SMAD4. Moreover, genes which were differentially expressed from the primordial to the late secondary stage follicles included GDF9, BMP15, AMH, INHBB, TGFβR3, SMAD4 and antagonists Follistatin (FST) and GREM1. Collectively, these data indicate that the active TGF-β superfamily pathways in early human folliculogenesis consist of primarily GDF9 combined with possible synergistic effects of BMP15 through the BMPR2 and intracellular activation of SMAD3 and SMAD4, and that AMH and INHBB are engaged in intrafollicular events from the onset of follicular growth. Moreover, the presence of multiple TGF-β/BMP antagonists imply that certain growth factors are subjected to local regulation on different levels that address another important level of intraovarian regulation of follicle development in humans.
authors.affiliation: Laboratory of Reproductive Biology, Section 5712, Copenhagen University Hospital, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.
authors.forename: Stine Gry
authors.initials: SG
authors.lastname: Kristensen
authors.forename: Kasper
authors.initials: K
authors.lastname: Andersen
authors.forename: Christian Alexandro
authors.initials: CA
authors.lastname: Clement
authors.forename: Stephen
authors.initials: S
authors.lastname: Franks
authors.forename: Kate
authors.initials: K
authors.lastname: Hardy
authors.forename: Claus Yding
authors.initials: CY
authors.lastname: Andersen
mesh_terms: D000328:Adult; D055430:Bone Morphogenetic Protein 15 / Q000235:genetics / Q000378:metabolism; D052006:Bone Morphogenetic Protein Receptors, Type II / Q000235:genetics / Q000378:metabolism; D005260:Female; D038681:Follistatin / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D015894:Genome, Human; D055106:Genome-Wide Association Study; D055429:Growth Differentiation Factor 9 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D006080:Ovarian Follicle / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D051785:Smad Proteins / Q000235:genetics* / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism
chemical_list: C525901:BMP15 protein, human; D055430:Bone Morphogenetic Protein 15; C503233:FST protein, human; D038681:Follistatin; C525897:GDF9 protein, human; C486399:GREM1 protein, human; D055429:Growth Differentiation Factor 9; D036341:Intercellular Signaling Peptides and Proteins; D018125:Receptors, Transforming Growth Factor beta; D051785:Smad Proteins; D016212:Transforming Growth Factor beta; C498218:BMPR2 protein, human; D052006:Bone Morphogenetic Protein Receptors, Type II
keywords: follicle development; gene expression; growth factors