Mechanisms Of Premature Cranial Fusion: Role Of Retinol Binding Protein 4 In Osteogenesis And Suture Fusion
Funder
National Health and Medical Research Council
Funding Amount
$555,855.00
Summary
Craniosynostosis is a condition where the skull bones fuse prematurely, affecting skull shape, vision and cognition. It occurs in 1 in 2,500 births. The only treatment is surgery, which is life-threatening, costly and may need to be repeated. By studying how fusion happens in this project we may be able to devise therapies to minimize the risks and need for re-operation. Here, we hope to show that modification of a single substance in the skull of mouse models can prevent premature bone fusion.
Antigen Receptor Sharing By Lymphocytes During An Immune Response
Funder
National Health and Medical Research Council
Funding Amount
$286,328.00
Summary
A successful immune response relies on the ability of immune cells to quickly mount a specific offensive against invading foreign pathogens like bacteria or viruses. The specificity of this offensive is governed by receptors that can recognise pathogens. To survive an infection the immune system must rapidly expand the number of immune cells that have receptors that recognise, and can therefore specifically combat, the infection. The underlying theory of immunology, the clonal selection theory, ....A successful immune response relies on the ability of immune cells to quickly mount a specific offensive against invading foreign pathogens like bacteria or viruses. The specificity of this offensive is governed by receptors that can recognise pathogens. To survive an infection the immune system must rapidly expand the number of immune cells that have receptors that recognise, and can therefore specifically combat, the infection. The underlying theory of immunology, the clonal selection theory, states that this expansion is mediated by the proliferation of immune cells selected on the basis of expressing a pathogen specific receptor. We hypothesise that in addition to this proliferation the immune system may also expand the number of immune cells expressing pathogen-specific receptors by transferring these receptors between cells by a means of cell-membrane sharing. Indeed, we have evidence that this does occur both in the test tube and in animals and can function to amplify the number of immune cells that can specifically recognise a pathogen and thereby help with immune response development. This grant aims to further advance our understanding of this novel phenomenon.Read moreRead less
Truncating Presenilin Mutations And Their Effects On Gamma-secretase Activity, Tau And Beta-catenin
Funder
National Health and Medical Research Council
Funding Amount
$414,005.00
Summary
Alzheimer's disease (AD) and cancer are increasingly important both in terms of human suffering and the burden of care it imposes on society and the economy. Sporadic (non-inherited) AD is the most common form of dementia but is poorly understood. The PRESENILIN genes, PSEN1 and PSEN2, are the major sites for mutations causing inherited AD and are also implicated in cancer. Using the zebrafish embryo model we have discovered that, contrary to current thought, mutations that truncate presenilin p ....Alzheimer's disease (AD) and cancer are increasingly important both in terms of human suffering and the burden of care it imposes on society and the economy. Sporadic (non-inherited) AD is the most common form of dementia but is poorly understood. The PRESENILIN genes, PSEN1 and PSEN2, are the major sites for mutations causing inherited AD and are also implicated in cancer. Using the zebrafish embryo model we have discovered that, contrary to current thought, mutations that truncate presenilin proteins potently suppress normal presenilin activity. (They are so called, dominant negatives). This means that they are lethal for embryo development and explains why such mutations have never been found in inherited AD. Notably, this discovery could only be made using a subtle form of gene manipulation that is possible in zebrafish embryos. Our work has also established the first assay for the non-apoptotic (non-cell death) function of PSEN2 and has shown that PSEN2 activity is inhibited by truncated PSEN1. This is the first indication of possible interaction between PSEN1 and PSEN2 proteins at normal physiological expression levels. Loss of presenilin activity promotes cancer. Truncated presenilin proteins could be produced by errors in gene transcription (aberrant transcript splicing) common in cancerous cells. This suggests that truncated, dominant negative forms of presenilin produced through aberrant splicing (or mutation in precancerous cells) might be common in tumour formation. The proposed research will define the region of PSEN1 in which truncation leads to dominant negative activity. This will allow further examination of the role of presenilins in the cell signalling pathways involved in AD and cancer. We will also investigate the role that age-related truncation of presenilins in human cells can play in the formation of sporadic AD. This may reveal a common molecular link between the inherited and sporadic forms of this disease.Read moreRead less
Insulin resistance (the inability of ordinarily insulin-sensitive tissues such as muscle and adipose tissue to respond to insulin) contributes to a number of diseases including diabetes and obesity. A key metabolic step in these tissues is the uptake of glucose from the blood stream. This step is accelerated by insulin thus allowing efficient clearance of glucose from the bloodstream after a meal. Our laboratory has played a major role in showing that insulin regulates glucose uptake into muscle ....Insulin resistance (the inability of ordinarily insulin-sensitive tissues such as muscle and adipose tissue to respond to insulin) contributes to a number of diseases including diabetes and obesity. A key metabolic step in these tissues is the uptake of glucose from the blood stream. This step is accelerated by insulin thus allowing efficient clearance of glucose from the bloodstream after a meal. Our laboratory has played a major role in showing that insulin regulates glucose uptake into muscle and adipose tissue by stimulating the movement of a glucose transport protein from inside the cell to the cell surface (see http:--www.imb.uq.edu.au-groups-james-glut4 for an animated description of this process). The purpose of this proposal is to dissect the molecular mechanisms by which this glucose transporter can be held inside the cell in the absence of insulin and then allowed to be released from this site moving to the surface in the presence of insulin. Our studies over the past 5 years have brought us much closer to understanding this process in detail. The identification of the molecules responsible for this regulatory step will not only aid our understanding of this process but it will also provide a valuable target for development of therapeutic agents that can be used to combat insulin resistance.Read moreRead less