Overweight and obesity are at epidemic proportions in Australia, reflecting the pattern in the developed and developing world. The main cause appears to be an energy mismatch, with excessive caloric consumption. One response of the body to excessive nutrient supply is energy storage in fat tissue and to aid in this the body also generates new fat tissue, termed adipogenesis (also known in cells as fat cell differentiation). In many people who gain excess body weight, fat tissue is abnormal and d ....Overweight and obesity are at epidemic proportions in Australia, reflecting the pattern in the developed and developing world. The main cause appears to be an energy mismatch, with excessive caloric consumption. One response of the body to excessive nutrient supply is energy storage in fat tissue and to aid in this the body also generates new fat tissue, termed adipogenesis (also known in cells as fat cell differentiation). In many people who gain excess body weight, fat tissue is abnormal and does not respond well to the chemical insulin, thus causing insulin resistance. This insulin resistant fat tissue is especially present in a central body (visceral) site. Insulin resistance related to this visceral fat predisposes to both diabetes and premature death from cardiovascular disease. Understanding how fat tissue develops and how it might cause insulin resistance is thus important in human health. One of the factors in fat that prevents normal development of fat tissue and which induces insulin resistance is transforming growth factor- (TGF- ). We have generated new data showing that two proteins which are increased by TGF- , termed connective tissue growth factor (CTGF) and insulin like growth factor binding protein-3, (IGFBP-3), prevent adipogenesis. We have shown this in cultured cells, and have found that CTGF and IGFBP-3 are increased in visceral fat in animal models of obesity and insulin resistance. Our preliminary work has further indicated how CTGF and IGFBP-3 might each work in the fat cell to prevent adipogenesis. This proposal will determine if TGF- works through CTGF and IGFBP-3 to block adipogenesis, and it will define how CTGF and IGFBP-3 have their inhibitory effects on fat cell differentiation. Cells in culture will be utilised and an animal model of dietary induced obesity and insulin resistance will help to define whether CTGF and IGFBP-3 prevent adipogenesis in vivo, furthering our understanding in how abnormal fat tissue may develop.Read moreRead less
Roles Of The Nuclear Growth Hormone Receptor In Cell Proliferation And Survival
Funder
National Health and Medical Research Council
Funding Amount
$429,387.00
Summary
We have discovered that the cell surface receptor for growth hormone travels to the cell nucleus in dividing cells, including cancer cells. Given the role of growth hormone in promoting growth postnatally, we seek to uncover how the nuclear receptor promotes proliferation directly, and by gene splicing. We have identified strong candidates for its direct actions through proteomics, and a DNA binding site for the receptor. Here we will investigate its role in proliferation, gene splicing and DNA ....We have discovered that the cell surface receptor for growth hormone travels to the cell nucleus in dividing cells, including cancer cells. Given the role of growth hormone in promoting growth postnatally, we seek to uncover how the nuclear receptor promotes proliferation directly, and by gene splicing. We have identified strong candidates for its direct actions through proteomics, and a DNA binding site for the receptor. Here we will investigate its role in proliferation, gene splicing and DNA strand break repair after cell irradiation.Read moreRead less
The Nuclear Growth Hormone Receptor- Its Actions And Mechanism Of Nuclear Translocation
Funder
National Health and Medical Research Council
Funding Amount
$531,696.00
Summary
We and others have found that cell surface receptors for growth factors such as EGF, FGF and growth hormone can be found in the nucleus of proliferating cells. We have shown that many cancers have elevated nuclear GH receptor including leukemia, breast and colon cancer. If we artificially target the GH receptor to the nucleus, the resulting cells are tumorigenic when injected into immunocompromised mice, rapidly form ing metastasising tumours. To create more effective inhibitors of this tumourog ....We and others have found that cell surface receptors for growth factors such as EGF, FGF and growth hormone can be found in the nucleus of proliferating cells. We have shown that many cancers have elevated nuclear GH receptor including leukemia, breast and colon cancer. If we artificially target the GH receptor to the nucleus, the resulting cells are tumorigenic when injected into immunocompromised mice, rapidly form ing metastasising tumours. To create more effective inhibitors of this tumourogenesis, and to define the physiological roles of nuclear GH receptor, we will define the transport process which carries the receptor to the nucleus and block it. We will also seek to define how the receptor in the nucleus interacts directly with DNA to inhibit programmed cell death. To carry out these projects we will use sophisticated proteomics -mass spectrometry to identify the proteins interacting with the receptor in the transport and gene activation processes. The role of candidates will be tested by preventing their expression or by direct inhibition of their action using drugs or dominant negative versions. These approaches will provide leads to new anti-cancer therapeutics, and therapies for blocking diabetic blindness and kidney failure.Read moreRead less
FUNCTIONAL ANALYSIS OF IGF-BINDING PROTEIN-2 MOLECULAR INTERACTIONS IN EARLY DEVELOPMENT AND DISEASE
Funder
National Health and Medical Research Council
Funding Amount
$551,328.00
Summary
Early development involves complex regulation of cell and organ growth. Cell migration and invasion are critical components of epithelial-mesenchymal transition (EMT) essential for early developmental, as well as injury repair and cancer. Common to these events is a highly expressed protein, insulin-like growth factor binding protein-2 (IGFBP-2), which appears to play a critical role in regulating the processes of cell migration and invasion. The underlying mechanisms of cellular regulation by I ....Early development involves complex regulation of cell and organ growth. Cell migration and invasion are critical components of epithelial-mesenchymal transition (EMT) essential for early developmental, as well as injury repair and cancer. Common to these events is a highly expressed protein, insulin-like growth factor binding protein-2 (IGFBP-2), which appears to play a critical role in regulating the processes of cell migration and invasion. The underlying mechanisms of cellular regulation by IGFBP-2 are major focus of this proposal, which brings together four major groups focussed on early development, neural injury repair, and cancer biology. We will use a range of in vitro and in vivo approaches to determine the underlying mechanisms of action of this critical protein. This project has the potential to point to novel therapeutic modalities in development, repair and cancer.Read moreRead less