I am a stem cell scientist working on the biology of human embryonic stem cells and their differentiation into cells of mesodermal (blood, endothelium and cardiomyocyte) and endodermal (pancreatic islet cells) lineages.
The Role Of Heterochromatin In Regulating Cellular Proliferation And Development
Funder
National Health and Medical Research Council
Funding Amount
$504,000.00
Summary
Fundamental to the development of a multicellular organism is that for each cell type performing a specialised function, a different set of genes are turned on with the remainder being shut off. One of the most significant unanswered questions in biology is how a cell-type specific gene expression profile is established during early development. The answer to this question has important implications in understanding normal and abnormal cellular processes. Gene expression in a cell occurs in the ....Fundamental to the development of a multicellular organism is that for each cell type performing a specialised function, a different set of genes are turned on with the remainder being shut off. One of the most significant unanswered questions in biology is how a cell-type specific gene expression profile is established during early development. The answer to this question has important implications in understanding normal and abnormal cellular processes. Gene expression in a cell occurs in the nucleus where genes are stored. In the nucleus, DNA is not in a free form but is covered with an equivalent weight of protein (histones) to form a structure known as chromatin. It has become clear that the chromatin structure encompassing a gene is the critical factor that determines whether a gene is expressed or silenced. We propose that developmental and cell-type specific mechanisms operate in a cell to assemble genes into highly specialised chromatin structures that permit (euchromatin) or restrict (heterochromatin) gene expression. In other words, the genome of each different cell type is organised into a unique and dynamic chromatin pattern and this pattern determines the gene expression profile. This investigation will show that the critical cellular mechanism that determines the chromatin pattern for a particular cell type is the regulation of the quantity and quality of heterochromatin. Specifically, we will demonstrate that this is achieved, in a developmental and tissue specific manner, by changing the make-up of chromosomal domains through the replacement of histone proteins with specialised forms of histones called variants . In addition, we will expose a new mechanism of how heterochromatin formation controls the rate of cellular proliferation. This information will provide new insights into how gene expression profiles are established at precise times in early development, and offer a new strategy to inhibit the proliferation of cancer cells.Read moreRead less
Fibrtic lung diseases are a major health burden, and are a leading causes of mortality and morbidity worldwide. These diseases are effectively incurable, and a considerable number eventually require lung transplants. As such these diseases are prime candidates for stem cell therapies to regenerate and repair the lung. However, the lack of knowledge about the precise identity, organisation and regulation of these cells; how to deliver them effectively to the damaged lung; and how to pre-condition ....Fibrtic lung diseases are a major health burden, and are a leading causes of mortality and morbidity worldwide. These diseases are effectively incurable, and a considerable number eventually require lung transplants. As such these diseases are prime candidates for stem cell therapies to regenerate and repair the lung. However, the lack of knowledge about the precise identity, organisation and regulation of these cells; how to deliver them effectively to the damaged lung; and how to pre-condition their site of lodgement to best harness their potential. This project aims to address these issues. We have recently identified a rare population of cells in the adult mouse lung which has a number of characteristics consistent with that of an adult stem cell. We are able to grow these cells in tissue culture, and we have preliminary data suggesting that they can regenerate lung tissue when transplanted. The aim of this project is to precisely identify these cells, develop methods for their isolation and determine their location in the lung. The assays we will develop in this model will then be used to identify stem cells in the bone marrow which have similar properties and which could potentially be used clinically to alleviate lung disease. The project brings together a group of investigators with unique expertise in the isolation and analysis of adult stem cells, and in clinical and experimental respiratory medicine to develop preclinical models in the mouse which are prerequisite for the developement and implementation of step cell based therapies for lung disease in humans.Read moreRead less
Transcriptional Regulation Of The Complement Receptor 2 Gene (CR2/CD21) During B Cell Lineage Committment
Funder
National Health and Medical Research Council
Funding Amount
$466,500.00
Summary
The complement system is a very important pathway within the human immune system. One of the receptors within this system is complement receptor 2 or CR2. CR2 has not only been shown to be important within the inflammatory response and defence against microbes but is also important in normal generation of a B cell immune response . B cells not only produce antibodies against foreign organisms but in some cases dysfunction of the B cell can bring about autoimmunity by production of antibodies aga ....The complement system is a very important pathway within the human immune system. One of the receptors within this system is complement receptor 2 or CR2. CR2 has not only been shown to be important within the inflammatory response and defence against microbes but is also important in normal generation of a B cell immune response . B cells not only produce antibodies against foreign organisms but in some cases dysfunction of the B cell can bring about autoimmunity by production of antibodies against self tissues and cells . How the CR2 gene turns on expression on different cells within the immune system is complex. The amount of receptor on the surface of antibody producing B cells has important implications to B cell biology. As CR2 expression is turned on at an important point within the antibody producing B cell and the levels of this receptor can influence B cell function, understanding how this gene is regulated is important.Read moreRead less
I am a developmental cell biologist and molecular geneticist focusing on mechanisms controlling cell proliferation and modelling the development of cancer in the vinegar fly, Drosophila.
Relaxin Signalling In The Endometrium And The Regulation Of Early Pregnancy
Funder
National Health and Medical Research Council
Funding Amount
$466,125.00
Summary
Relaxin is a hormone, that is made in the ovary and the uterus, and plays a very important role in supporting the growth and development of the uterus so that the young embryo can implant properly. In fact, early pregnancy loss is associated with altered levels of relaxin in the blood. Very little is known about how relaxin works in the uterus. This project aims to address this important function, and makes use of cultured uterine cells prepared from tissues taken from women undergoing hysterect ....Relaxin is a hormone, that is made in the ovary and the uterus, and plays a very important role in supporting the growth and development of the uterus so that the young embryo can implant properly. In fact, early pregnancy loss is associated with altered levels of relaxin in the blood. Very little is known about how relaxin works in the uterus. This project aims to address this important function, and makes use of cultured uterine cells prepared from tissues taken from women undergoing hysterectomy for fibroids or similar illnesses. When these cells are grown in culture, we can mimic in vitro many of the events that occur in early pregnancy, causing the cells to differentiate and grow just as they would in vivo. Relaxin appears to exert its important effects on these cells by causing the concentration of the second messenger cAMP in the so-called stromal cells to increase greatly and in a sustained manner. It is this cAMP which is then responsible for many of the changes which are essential for healthy pregnancy. A knowledge of the molecular mechanisms behind these effects would help us firstly to understand how the uterus becomes receptive to an implanting embryo, and may explain why some women lose their babies in early pregnancy, or develop some of the negative symptoms associated with placental development such as growth restriction and preeclampsia. Relaxin appears to stimulate cells through the mediation of a new type of cell surface receptor, called LGR7. Whilst structurally this receptor looks like those for many other hormones, belonging to the group of so-called G-protein coupled receptors, it does not behave like these in natural uterine cells. Instead it appears to make use of completely new signaling pathways inside the cells. This project aims to unravel and understand these new pathways, thus providing information not only of importance for diagnosis and treatment of early pregnancy problems, but also of relevance for all other similar receptors.Read moreRead less
Tyrosine Kinases And Phosphatases In Cell Cycle Checkpoint Responses
Funder
National Health and Medical Research Council
Funding Amount
$513,946.00
Summary
In order for an organism to grow and develop, the cells that make up the tissues and organs need to undergo a process of cellular division, wherein individual cells grow and then divide into two cells. During this process of cellular growth and division the entire genome needs to be duplicated (this occurs during S-phase) and then divided equally into the two daughter cells. In S-phase several so-called 'checkpoint' mechanisms exist which ensure that this occurs in an orderly and precise manner. ....In order for an organism to grow and develop, the cells that make up the tissues and organs need to undergo a process of cellular division, wherein individual cells grow and then divide into two cells. During this process of cellular growth and division the entire genome needs to be duplicated (this occurs during S-phase) and then divided equally into the two daughter cells. In S-phase several so-called 'checkpoint' mechanisms exist which ensure that this occurs in an orderly and precise manner. The so-called 'DNA replication checkpoint' delays S-phase progression in response to 'replication stresses' that may otherwise cause DNA damage. Protein tyrosine kinases (PTKs) are hyperactivated in many human solid tumours and blood malignancies contributing to varied aspects of tumour progression. Our preliminary studies indicate that the inactivation of PTKs by protein tyrosine phosphatases may be essential for the suppression of S-phase progression in response to replication stress. Our goal is to understand the molecular mechanisms by which PTKs and tyrosine phosphatases contribute to S-phase checkpoints. Our studies will provide important insights into DNA replication stress-induced checkpoint responses in mammals and identify unprecedented mechanisms by which hyperactivated PTKs may contribute to tumour development.Read moreRead less
Dissecting a hematopietic transcription factor complex. The development of mature active cells is a highly complex and coordinated process that is controlled largely by groups of interacting regulatory proteins. We are trying to understand, at a very detailed level, how a specific group of these proteins interact to regulate both normal blood cell development and the onset of childhood leukemias. Using this information we will try to develop reagents that can be used to inhibit these interaction ....Dissecting a hematopietic transcription factor complex. The development of mature active cells is a highly complex and coordinated process that is controlled largely by groups of interacting regulatory proteins. We are trying to understand, at a very detailed level, how a specific group of these proteins interact to regulate both normal blood cell development and the onset of childhood leukemias. Using this information we will try to develop reagents that can be used to inhibit these interactions and be used as lead compounds for treatments for disease.Read moreRead less
Investigating the activator function of the Bim protein. Apoptosis is a research area where Australia has had long standing success. The first observations of this important process were made by Prof John Kerr in the 60's and 70's. A molecular renaissance developed in the late 80's and has led to the current explosion in this area of research. Many of these recent studies have been conducted at the Walter and Eliza Hall Institute. Our scientific endeavour is aimed at broadening the understanding ....Investigating the activator function of the Bim protein. Apoptosis is a research area where Australia has had long standing success. The first observations of this important process were made by Prof John Kerr in the 60's and 70's. A molecular renaissance developed in the late 80's and has led to the current explosion in this area of research. Many of these recent studies have been conducted at the Walter and Eliza Hall Institute. Our scientific endeavour is aimed at broadening the understanding of the mechanisms of cell death using genetically modified mouse models. Insights gained through this project will have far reaching implications for the design of new drugs to combat cancer and degenerative diseases.Read moreRead less
The role of the transcription factor Runx2 during mammary gland development and lactation. This proposal will further our understanding of mammary gland development and lactation and the mechanisms controlling mammary cell fate decisions such as differentiation. Regulation of cell fate lies at the core of most aspects of cell biology from normal development to dysfunction such as cancer. The knowledge gleamed from this project also has the potential to make economic gains for Australia by increa ....The role of the transcription factor Runx2 during mammary gland development and lactation. This proposal will further our understanding of mammary gland development and lactation and the mechanisms controlling mammary cell fate decisions such as differentiation. Regulation of cell fate lies at the core of most aspects of cell biology from normal development to dysfunction such as cancer. The knowledge gleamed from this project also has the potential to make economic gains for Australia by increasing the profitability and ensuring the sustainability of both the dairy and meat industries. Better understanding of the mechanisms controlling mammary epithelial cell differentiation should enable augmentation of lactation such as increasing milk protein content, using marker assisted selection (of targets such as Runx2) in cattle.Read moreRead less