This project aims to study how the two main hormones, FSH and testosterone, control the development and production of sperm throughout adult life. In previous NHMRC-supported research we were the first to overturn the long-standing belief that FSH was vital to the start of sperm production in all warm-blooded animals. This insight was achieved from experiments using a genetically modified strain of mouse. We used this mouse strain to develop a new experimental paradigm to provide unique insight ....This project aims to study how the two main hormones, FSH and testosterone, control the development and production of sperm throughout adult life. In previous NHMRC-supported research we were the first to overturn the long-standing belief that FSH was vital to the start of sperm production in all warm-blooded animals. This insight was achieved from experiments using a genetically modified strain of mouse. We used this mouse strain to develop a new experimental paradigm to provide unique insight into how hormones start up and support sperm production. In this present proposal we wish to take this research further. Although we have shown that FSH is not vital to the startup or continuing of sperm production, we believe it still does have an important role in causing the growth of a large enough population of Sertoli cells of the testis. These highly specialised cells have the unique job to support, nourish and coordinate the production of sperm. Sertoli cells are known to be the only target in the body for FSH and so that FSH must act upon them exclusively. We believe this occurs almost solely during early life - starting before birth and into early infancy - well before adult life when sperm are produced for the first time. In this way these processes being studied determine the size of mature testis. Our new approaches to studying the question of how the two main hormones control sperm production involve developing new types of genetically modified mice which have extra and exclusive FSH activity as well as some new research methods to be applied to understanding how FSH acts on the Sertoli cell using techniques derived from gene therapy and from cell transplantation. This research has the possibility to uncover new causes of previously unexplained male infertility (the majority having no known cause so far), to help develop better hormonal male contraceptives, and to quetion the need for expensive treatments for some infertile men.Read moreRead less
This project aims to study the hormonal control of Sertoli cell development and function. In the testis, these highly specialised cells provide essential nutritional and structural support for sperm production. In current NHMRC-supported research we created a unique mouse model to study the individual roles of two key reproductive hormones FSH and testosterone in spermatogenesis. This novel approach involved the selective expression of transgenic FSH on the hormone-deficient background of hpg mi ....This project aims to study the hormonal control of Sertoli cell development and function. In the testis, these highly specialised cells provide essential nutritional and structural support for sperm production. In current NHMRC-supported research we created a unique mouse model to study the individual roles of two key reproductive hormones FSH and testosterone in spermatogenesis. This novel approach involved the selective expression of transgenic FSH on the hormone-deficient background of hpg mice, which normally lack both androgens and FSH. Our analysis revealed that FSH provided the main stimulation for Sertoli cell and early germ cell proliferation, whereas FSH required testosterone for later stages of sperm formation. In this proposal we now plan to investigate FSH and the changing steroidal contributions during the critical postnatal stage of Sertoli cell development. We will study individual of combined actions of FSH and steroids, including the controversial role of estradiol in Sertoli and germ cell function, which may all have profound consequences on sperm production and male fertility. We will also establish unique mouse models to address fundamental questions about the mechanisms of androgen actions in the testis, and the requirement for androgen receptor expression in Sertoli and neighbouring peritubular cells for the overall testosterone response. Furthermore, we will use new microarray gene screening technology to identify the FSH- and androgen-regulated gene pathways during Sertoli cell proliferation. This research has relevance to the controversial view of environmental steroids affecting human testicular development and reducing sperm counts, and offers the potential to uncover new causes of previously unexplained male infertility or testicular cancers, and to help develop better strategies for hormonal male contraceptives, and treatments for male infertitliy or cancer.Read moreRead less
Hormonal Control Of Serotli Cell Maturation And Function
Funder
National Health and Medical Research Council
Funding Amount
$512,898.00
Summary
This project will determine the key roles of androgen in the Sertoli cell, a unique highly specialised cell that provides essential nutritional and structural support for sperm production. Androgen acts via the androgen receptor (AR), which is vital for initiating and maintaining sperm development. In current NHMRC-funded research we successfully established new mouse models designed to study AR, in particular its regulation of gene expression, in the Sertoli cell. We revealed that genomic AR ac ....This project will determine the key roles of androgen in the Sertoli cell, a unique highly specialised cell that provides essential nutritional and structural support for sperm production. Androgen acts via the androgen receptor (AR), which is vital for initiating and maintaining sperm development. In current NHMRC-funded research we successfully established new mouse models designed to study AR, in particular its regulation of gene expression, in the Sertoli cell. We revealed that genomic AR activity within Sertoli cells is essential for 'induction' of complete sperm development. Ongoing work will develop unique 'inducible' transgenic models that will allow, for the first time, selective analysis of Sertoli AR in both 'developing' and 'adult' testes. Our innovative models will allow AR function to be switched on or off at any stage of development, providing unique opportunity to determine the key AR-regulated factors and pathways controlling induction, maintenance or restoration of sperm production. In past NHMRC research we created a novel transgenic model to study another major reproductive hormone, FSH. Using the hormone-deficient background of 'hpg' mice, we found that androgen and FSH act synergistically in the developing 'meiotic' germ cells that form sperm. Using the latest microarray gene technology we generated datasets of androgen-regulated genes with or without FSH activity, which combined with our unique transgenic AR and FSH models, will be used to identify key pathways, including those enhanced by androgen-FSH synergism, in the early testicular response. Our research will provide new knowledge of the precise roles and pathways of testicular AR actions, to ultimately identify key genetic and regulatory factors as targets for significantly improved therapy for male infertility, gonadal tumours, or contraception.Read moreRead less
Follicle-stimulating hormone (FSH) is vital for egg development, female fertility and health, and is widely used in assisted reproduction technology. But high levels of FSH are associated with premature infertility and menopause, and may lead to diseases like ovarian cancer. Understanding the biological pathways activated by elevated FSH may lead to new treatments for infertility and ovarian diseases (eg. cancer), as well as advancing new strategies for contraception.