The Molecular Processes Involved In Age-related Human Nuclear Cataract
Funder
National Health and Medical Research Council
Funding Amount
$450,750.00
Summary
This project seeks to understand the molecular basis for age-related nuclear cataract, and in particular the role of our UV filter compounds. By gaining an understanding of the mechanism of cataract we hope to be able to develop ways to interfere with the process and thus prevent, or at least delay, human cataract. Experiments will be undertaken to determine the extent of covalent binding of the most reactive UV filter, 3-hydroxykynurenine, to lens proteins (crystallins) isolated from normal hum ....This project seeks to understand the molecular basis for age-related nuclear cataract, and in particular the role of our UV filter compounds. By gaining an understanding of the mechanism of cataract we hope to be able to develop ways to interfere with the process and thus prevent, or at least delay, human cataract. Experiments will be undertaken to determine the extent of covalent binding of the most reactive UV filter, 3-hydroxykynurenine, to lens proteins (crystallins) isolated from normal human lenses of various ages, and from cataract lenses. In addition, the properties of lens crystallins that have been modified in model systems by kynurenine, 3-hydroxykynurenine and 3-hydroxykynurenine glucoside will be investigated. This will include examination of the impact of the UV filter modifications on the formation of protein radicals following exposure of the crystallins to UV light and an investigation of the hypothesis that the protein-bound UV filters act as sites for both complexing of metals and their chemical reduction. Oxidation is known to be involved in cataract and experiments will also be undertaken to measure the concentration of oxygen in the lens nucleus, so that the model studies more accurately reflect conditions within the lens, and to see if the levels of oxygen may inflluence the onset of cataract.Read moreRead less
ROLE OF PROTEASE ACTIVATED RECEPTORS IN CYSTIC FIBROSIS LUNG PATHOLOGY
Funder
National Health and Medical Research Council
Funding Amount
$176,521.00
Summary
Cystic fibrosis is a major debilitating disease which eventually kills those with the genetic defect. The lungs of patients become infected with the bacteria Pseudomonas aeruginosa or Burkolderia cepacia which initiate a chronic and vicious cycle of inflammation resulting in lung failure. Proteases released by the organisms as well as host cells (neutrophils) involved in clearing the infections play a major role in this cycle by causing the release of molecules (cytokines and mediators) from the ....Cystic fibrosis is a major debilitating disease which eventually kills those with the genetic defect. The lungs of patients become infected with the bacteria Pseudomonas aeruginosa or Burkolderia cepacia which initiate a chronic and vicious cycle of inflammation resulting in lung failure. Proteases released by the organisms as well as host cells (neutrophils) involved in clearing the infections play a major role in this cycle by causing the release of molecules (cytokines and mediators) from the respiratory epithelium. These, in turn, stimulate the movement of neutrophils from the blood to the lung where damage then ensues. How these proteases stimulate release is unclear but studies suggest other proteases involved in inflammation induce release through their interaction with a novel group of protease activated receptors (PAR). In this study, we wish to determine whether PAR are activated or inactivated by host and bacterial proteases commonly seen in the lungs of CF patients. If PAR are activated, it may be possible to develop antagonists which target specific PARS to modulate respiratory epithelial cell function. If inactivated, preservation by adjunct protease inhibitor treatment may be highly beneficial. We will use in vitro technology and cells derived from non-CF and CF patients. This study has great potential in the development of adjunct anti-inflammatory therapy for the treatment of both CF and other inflammatory lung diseases.Read moreRead less
Novel Upstream Regulatory And Down-stream Signaling Mechanisms Of The Src-family Protein Kinases
Funder
National Health and Medical Research Council
Funding Amount
$363,639.00
Summary
Normal cell growth and division are governed by the balanced action of two groups of enzymes - the enzymes encoded by the proto-oncogenes (precursors of cancer-causing genes) and the tumour suppressor genes. Abnormalities in the regulation of these enzymes cause cancer. Indeed, over-stimulation of a group of proto-oncogenic enzymes called the Src-family kinases (SFKs) is the major contributing factor to most human cancers. In this application, we propose to study how inactivation of SFKs by thei ....Normal cell growth and division are governed by the balanced action of two groups of enzymes - the enzymes encoded by the proto-oncogenes (precursors of cancer-causing genes) and the tumour suppressor genes. Abnormalities in the regulation of these enzymes cause cancer. Indeed, over-stimulation of a group of proto-oncogenic enzymes called the Src-family kinases (SFKs) is the major contributing factor to most human cancers. In this application, we propose to study how inactivation of SFKs by their native inhibitor CHK suppresses cancer formation and how over-stimulation of SFKs causes cancer. Exactly how CHK inactivates SFKs remains unclear. Recently, we discovered a novel mechanism employed by CHK to inhibit SFKs. In this mechanism, CHK binds to SFKs tightly and the binding alone is sufficient to completely shut down SFK activity. As this novel inhibitory mechanism of CHK can be exploited for the development of synthetic SFK inhibitors for cancer treatment, we propose to unravel how CHK tightly binds to SFKs and how the binding inhibits the cancer-promoting activity of SFKs. How over-stimulation of SFKs induces the development of human cancer has been an important outstanding question in cancer research. Recently, we and two groups of researchers in Texas achieved breakthroughs in answering this question. The Texan groups discovered that the over-stimulated SFKs cause cancer by shutting down the anti-tumour activity of a tumour suppressor called PTEN. We complemented their findings by discovering how SFKs shut down PTEN activity - SFKs shut down PTEN activity by a chemical modification process called phosphorylation. In this application, we propose to study how SFKs modify PTEN and how phosphorylation shuts down the tumour suppressor activity of PTEN. In summary, our studies will benefit the development of two types of anti-cancer therapeutics: (i) those mimicking CHK binding and inhibition of SFKs, and (ii) those interfering with phosphorylation of PTEN by SFKs.Read moreRead less
Invasive Assessment Of Pulmonary Vascular Physiology - Novel Methods For Early Detection Of Pulmonary Vascular Disease
Funder
National Health and Medical Research Council
Funding Amount
$274,352.00
Summary
Pulmonary vascular disease (PVD) is a lethal condition characterised by progressive destruction of the lung blood vessels. One major problem with PVD is that diagnosis is often made very late in the illness, when the pulmonary blood pressure rises. This project aims to develop a novel method to detect the early and clinically silent phase of PVD, by assessing the lung's blood vessel reserves. Early diagnosis of PVD will enable earlier treatment thereby improving prospects for treatment.
During reverse transcription, the positive-strand HIV-1 RNA genome is converted into a double-stranded DNA copy which can be permanently insert into the host cell genome. Our laboratory and others have shown that reverse transcription requires a complex array of molecules, which includes the viral RNA. These RNA can be organised into elaborate structures that have only been partially defined. Genetic experiments have revealed that one of these RNA structures, called TAR, is required for optimal ....During reverse transcription, the positive-strand HIV-1 RNA genome is converted into a double-stranded DNA copy which can be permanently insert into the host cell genome. Our laboratory and others have shown that reverse transcription requires a complex array of molecules, which includes the viral RNA. These RNA can be organised into elaborate structures that have only been partially defined. Genetic experiments have revealed that one of these RNA structures, called TAR, is required for optimal initiation of reverse transcription (the first step of reverse transcription), but the precise mechanism is unknown. Recent advances in our laboratory have enabled a comprehensive study of the role played by TAR RNA in reverse transcription. Our leading hypotheses regarding the mechanism is required that TAR interacts with other RNA sequences or Reverse transcriptase in the initiation complex so that the reaction is optimal. This proposal will investigate these two leading hypotheses. Given the enormity of the HIV pandemic and the many recent reports from the United States that most patient isolated virus is resistant to at least one antiretroviral drug, these studies have as an outcome the identification and characterisation of important new key molecules towards which antiretroviral strategies can be designed.Read moreRead less
The Mechanism Of Tat-enhanced Reverse Transcription In HIV-1
Funder
National Health and Medical Research Council
Funding Amount
$282,750.00
Summary
During reverse transcription, the positive-strand HIV-1 RNA genome is converted into a double-stranded DNA copy which can be permanently insert into the host cell genome. Many HIV-1 proteins including Tat contribute to the efficiency of reverse transcription. There are two competing hypotheses to explain how Tat enhances reverse transcription. The indirect mechanism hypothesis holds that Tat-enhanced reverse transcription is due to the combined effects of the Tat-induced expression of cellular g ....During reverse transcription, the positive-strand HIV-1 RNA genome is converted into a double-stranded DNA copy which can be permanently insert into the host cell genome. Many HIV-1 proteins including Tat contribute to the efficiency of reverse transcription. There are two competing hypotheses to explain how Tat enhances reverse transcription. The indirect mechanism hypothesis holds that Tat-enhanced reverse transcription is due to the combined effects of the Tat-induced expression of cellular genes. The direct mechanism hypothesis is that Tat functions directly during RTN, implying it is a virion protein. Our recent genetic and biochemical data provide strong evidence that a novel form of Tat, which we call vTat, has a direct role in RTN. This proposal will investigate these two leading hypotheses. Given the enormity of the HIV pandemic and the many recent reports from the United States that most patient isolated virus is resistant to at least one antiretroviral drug, these studies have as an outcome the identification and characterisation of important new key molecules towards which antiretroviral strategies can be designed.Read moreRead less