The objective of this research proposal is to understand the role of activin in the control of pituitary FSH synthesis. Activin is produced by the pituitary where it regulates FSHbeta1 gene expression. Activin controls many other target tissues and functions including granulosa cell proliferation, theca cell steroid production, hematopoietic cell differentiation, and neuronal survival. By using one growth factor for a variety of physiological functions, organisms have limited the number of signaling pathways that are necessary for complex cellular functions and reduced the evolutionary pressure to devise larger genomes. Thus, the challenge is to understand how one factor, with a limited repertoire of signaling components, is able to selectively control such a broad array of gene activity. We hypothesize that the basis for the idiosyncratic response of each target cell to activin is due to pathway-specific transcription factors known as Smads, tissue-selective co-regulators, and the DNA promoter itself. Thus, activin can regulate the synthesis of FSH in the pituitary without turning on hemoglobin production in an inappropriate manner. The signaling pathway leading to regulated FSH production by the pituitary is the focus of this grant. Our preliminary studies identify the proximal 388 base pairs of the FSHb promoter as the activin-responsive region of the gene, establish a role for Smad3 in FSHb gene expression, and identify Pitx2 as a homeobox gene product involved in pituitary-specific FSH production. The central hypothesis that we will address is that activin controls gonadotrope function through the specific DNA and protein binding properties of Smad3 and Pitx2, and that these factors and their structural properties are essential to the regulation of FSH in vivo. There are three interrelated experimental aims in this proposal. The first two aims utilize molecular and biochemical approaches to investigate the mechanism of Smad3 and Pitx2 regulation of FSHb gene transcription. The last aim investigates the specific contribution of Pitx2 to pituitary FSH regulation using transgenic mice. These studies are expected to provide insight into tissue-restricted activin signaling and will contribute to a more complete understanding of normal fertility and the mechanisms that may underlie diseases in both men and women resulting from inappropriate pituitary FSH synthesis.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD044464-04
Application #
7173014
Study Section
Biochemical Endocrinology Study Section (BCE)
Program Officer
Lamar, Charisee A
Project Start
2004-02-01
Project End
2009-01-31
Budget Start
2007-02-01
Budget End
2008-01-31
Support Year
4
Fiscal Year
2007
Total Cost
$294,121
Indirect Cost
Name
Northwestern University at Chicago
Department
Obstetrics & Gynecology
Type
Schools of Medicine
DUNS #
005436803
City
Chicago
State
IL
Country
United States
Zip Code
60611
Kim, So-Youn; Zhu, Jie; Woodruff, Teresa K (2011) A truncated, activin-induced Smad3 isoform acts as a transcriptional repressor of FSH* expression in mouse pituitary. Mol Cell Endocrinol 342:64-72
Moore, Brandon C; Kohno, Satomi; Cook, Robert W et al. (2010) Altered sex hormone concentrations and gonadal mRNA expression levels of activin signaling factors in hatchling alligators from a contaminated Florida lake. J Exp Zool A Ecol Genet Physiol 313:218-30
Lei, Lei; Jin, Shiying; Mayo, Kelly E et al. (2010) The interactions between the stimulatory effect of follicle-stimulating hormone and the inhibitory effect of estrogen on mouse primordial folliculogenesis. Biol Reprod 82:13-22
Do, Thuy-Vy; Kubba, Lena A; Du, Hongyan et al. (2008) Transforming growth factor-beta1, transforming growth factor-beta2, and transforming growth factor-beta3 enhance ovarian cancer metastatic potential by inducing a Smad3-dependent epithelial-to-mesenchymal transition. Mol Cancer Res 6:695-705
Sinkevicius, Kerstin W; Burdette, Joanna E; Woloszyn, Karolina et al. (2008) An estrogen receptor-alpha knock-in mutation provides evidence of ligand-independent signaling and allows modulation of ligand-induced pathways in vivo. Endocrinology 149:2970-9
Woodruff, Teresa K; Walker, Cheryl Lyn (2008) Fetal and early postnatal environmental exposures and reproductive health effects in the female. Fertil Steril 89:e47-51
Do, Thuy-Vy; Kubba, Lena A; Antenos, Monica et al. (2008) The role of activin A and Akt/GSK signaling in ovarian tumor biology. Endocrinology 149:3809-16
Burdette, Joanna E; Woodruff, Teresa K (2007) Activin and estrogen crosstalk regulates transcription in human breast cancer cells. Endocr Relat Cancer 14:679-89
Lee, Jiyoun; Burdette, Joanna E; MacRenaris, Keith W et al. (2007) Rational design, synthesis, and biological evaluation of progesterone-modified MRI contrast agents. Chem Biol 14:824-34
Suszko, Magdalena I; Woodruff, Teresa K (2006) Cell-specificity of transforming growth factor-beta response is dictated by receptor bioavailability. J Mol Endocrinol 36:591-600

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