Molecular Mechanisms Of Cartilage Degeneration In Osteoarthritis
Funder
National Health and Medical Research Council
Funding Amount
$457,517.00
Summary
Arthritis affects 15% of the entire Australian population and 50% in people over 60. The most common form of joint disease by far is osteoarthritis (OA). One of the central features of OA is the breakdown of the cartilage that covers the ends of bones in joints, and this is a major determinant of the long term outcome and need for joint replacement surgery. There are no current therapies that halt or reverse cartilage breakdown in OA. This is largely due to our incomplete understanding of the mo ....Arthritis affects 15% of the entire Australian population and 50% in people over 60. The most common form of joint disease by far is osteoarthritis (OA). One of the central features of OA is the breakdown of the cartilage that covers the ends of bones in joints, and this is a major determinant of the long term outcome and need for joint replacement surgery. There are no current therapies that halt or reverse cartilage breakdown in OA. This is largely due to our incomplete understanding of the molecular changes and pathways involved in both the onset and progression of cartilage breakdown. Powerful new genomic approaches allow simultaneous screening of changes in a broad profile of genes, particulalrly in humans and mice following complete sequencing of their genomes. By applying this new technology in the earliest stages of cartilage degeneration in OA, the role of novel genes and the pathways involved in the onset of this disease process can be discovered. However, to investigate changes at the initiation of disease, tissue from animal rather than human joints must be used due to the difficulty in obtaining pre-symptomatic human cartilage. In order to maximise the number of genes screened, cartilage from a novel surgically induced model of OA in mice will be used in this study. We have developed micro dissection and linear mRNA amplification methods to overcome inherent problems with tissue availability from this small animal species. Successful completion of these studies will for the first time allow identification of the complex changes that occur in early OA. An important and likely outcome of this research will be identification of novel matrix proteins and regulatory molecules that will provide critical information for the development of new diagnostic and therapeutic approaches to OA.Read moreRead less
Dissection Of The Mechanisms Of Action Of Evolutionarily Conserved Apoptotic Pathway Components
Funder
National Health and Medical Research Council
Funding Amount
$253,500.00
Summary
Animals eliminate unwanted cells through a highly controlled process termed apoptosis. Defects in apoptosis can contribute to cancer or autoimmune disease. Conversely, diseases such as stroke and Alzheimer's disease have been linked to excessive cell death. To develop drugs that promote apoptosis when it fails to occur, or prevent inappropriate cell death, it is necessary to elucidate the molecular mechanisms controlling apoptosis. The first recognised component of the mammalian cell death machi ....Animals eliminate unwanted cells through a highly controlled process termed apoptosis. Defects in apoptosis can contribute to cancer or autoimmune disease. Conversely, diseases such as stroke and Alzheimer's disease have been linked to excessive cell death. To develop drugs that promote apoptosis when it fails to occur, or prevent inappropriate cell death, it is necessary to elucidate the molecular mechanisms controlling apoptosis. The first recognised component of the mammalian cell death machinery was Bcl-2; a protein associated with development of cancer. Despite much research since then, the way in which Bcl-2 and related proteins function is still unknown. This project capitalises on previous genetic and biochemical studies in a model genetic organism (the roundworm) to address this important issue. Animal cell death pathway components can be introduced into yeast such that activation of the introduced pathways leads to yeast death and its inhibition promotes yeast survival. We have used this approach to reconstitute the worm cell death pathway and a major mammalian apoptosis pathway in yeast. Yeast strains bearing these reconstituted pathways will be used to test functional equivalence of candidate mammalian proteins and their putative roundworm counterparts. The system will also be exploited to identify and characterise novel proteins that regulate cell death in mammals and worms. Understanding the way in which key molecules regulate apoptosis will assist in the development of diagnostic and therapeutic reagents for many diseases in which cell death regulation is perturbed. This project capitalises on the evolutionary conservation of apoptosis to characterise the mechanisms of action of important mammalian apoptotic regulators and to seek novel mammalian apoptotic pathway components. Proteins identified in this way are likely to be important apoptotic regulators, as our approach ensures that their functions are evolutionarily conserved.Read moreRead less
Evolutionary Conservation Of Caspase Regulatory Mechanisms
Funder
National Health and Medical Research Council
Funding Amount
$585,215.00
Summary
Apoptosis is a highly controlled process by which metazoans eliminate unwanted and dangerous cells. Dysregulation of apoptosis can contribute to many conditions including cancer, autoimmune and degenerative diseases. To develop therapeutic reagents that promote cell death when it fails to occur, or prevent it from happening inappropriately, it is necessary to understand the mechanisms controlling apoptosis. To date, many of the important insights into mammalian cell death signalling have been in ....Apoptosis is a highly controlled process by which metazoans eliminate unwanted and dangerous cells. Dysregulation of apoptosis can contribute to many conditions including cancer, autoimmune and degenerative diseases. To develop therapeutic reagents that promote cell death when it fails to occur, or prevent it from happening inappropriately, it is necessary to understand the mechanisms controlling apoptosis. To date, many of the important insights into mammalian cell death signalling have been informed by studies of apoptotic pathways in simpler, experimentally tractable model organisms. This project will exploit biochemical approaches and powerful yeast-based tools developed by CI-A to further explore cell death pathways of the nematode Caenorhabditis elegans, and compare these with mammalian apoptosis pathways. Key findings will be verified using genetic approaches. Most apoptotic stimuli ultimately kill mammalian, insect or nematode cells by triggering activation of proteases termed caspases. However, the mechanisms by which caspase activity is regulated appear to differ somewhat between mammals and worms. We will address two general possibilities: either these animals really do differ significantly in the upstream regulation of cell death pathways, or that functional counterparts of key components have not hitherto been identified or fully characterised. Understanding the way in which mammalian apoptosis is regulated will aid in the design of diagnostic and therapeutic reagents for the many diseases in which dysregulation of apoptosis has been implicated. This project seeks to define the extent to which apoptotic regulation is conserved between mammals and nematodes. This knowledge will enable researchers to maximise the utility of nematode cell death models for the further elucidation of mammalian cell death regulatory mechanisms, and to explore how apoptosis can be manipulated for clinical benefit.Read moreRead less
Skeletal disease is a major problem for children with mucopolysaccharidoses (MPS). Patients suffer from early onset osteoporosis and osteoarthritis, severely affecting their quality of life. We will evaluate a lentiviral gene therapy vector developed in-house for its capacity to transduce bone, cartilage, synovial and ligament cells in a mouse model of MPS VI. Our goal is to generate high level, sustained expression of the deficient MPS enzyme and alter the course of skeletal disease in MPS.
Cholinergic Abnormalities In Alzheimer's Disease: Identification Of Novel Therapeutic Targets
Funder
National Health and Medical Research Council
Funding Amount
$478,500.00
Summary
The aim of this project is to develop new drugs for the treatment of Alzheimer's disease. Alzheimer's disease is a disease of ageing commonly associated with memory loss. The disease is caused by the build up of amyloid protein in the brain. However, it is not known how amyloid protein causes degeneration of normal brain function. Our previous studies have shown that amyloid protein targets two components which are important for normal brain function. These components are 1) acetylcholinesterase ....The aim of this project is to develop new drugs for the treatment of Alzheimer's disease. Alzheimer's disease is a disease of ageing commonly associated with memory loss. The disease is caused by the build up of amyloid protein in the brain. However, it is not known how amyloid protein causes degeneration of normal brain function. Our previous studies have shown that amyloid protein targets two components which are important for normal brain function. These components are 1) acetylcholinesterase and 2) nicotinic receptors, which are known to be important for memory. The aim of this application is to identify the mechanisms by which amyloid protein targets acetylcholinesterase and nicotinic receptors and to design inhibitors of this interaction which may ultimately provide a platform for future drug development.Read moreRead less
PArkin Co-Regulated Gene (PACRG), Parkin And Parkinsonism.
Funder
National Health and Medical Research Council
Funding Amount
$397,740.00
Summary
Parkinson's disease (PD) is a common neurodegenerative disorder affecting greater than two percent of individuals over the age of 65. The disease is characterised by tremor, slowness of movement, rigidity and postural instability. Current treatment regimes may provide some measure of symptomatic relief, but currently there is no treatment to halt or slow the progression of this debilitating disease. PD currently affects an estimated 35,000 people in Australia and this figure is predicted to incr ....Parkinson's disease (PD) is a common neurodegenerative disorder affecting greater than two percent of individuals over the age of 65. The disease is characterised by tremor, slowness of movement, rigidity and postural instability. Current treatment regimes may provide some measure of symptomatic relief, but currently there is no treatment to halt or slow the progression of this debilitating disease. PD currently affects an estimated 35,000 people in Australia and this figure is predicted to increase significantly as the population ages. PD is a complex disorder, the causes and disease mechanisms are not well understood. However, in the past 10 years several genes have been identified that can cause PD when disrupted. We have identified a new gene that we believe may be involved in PD. The overall aim of this proposal is to characterise this gene and what role it plays in the development of PD. Understanding the expression and function of this gene may significantly advance our understanding of this disorder. Using these results, we aim to model Parkinson's disease in cellular and animal systems; these may provide powerful insight into the molecular pathway(s) perturbed in PD and a means to develop novel therapeutic approaches to alleviate or prevent the disorder.Read moreRead less
DAMAGE TO SPECIFIC MITOCHONDRIAL MEMBRANE PROTEINS DURING OXIDATIVE STRESS AND THE AGEING PROCESS
Funder
National Health and Medical Research Council
Funding Amount
$195,982.00
Summary
During the ageing process and exposure to certain drugs or chemicals, oxygen radicals are produced within cells and tissues. If unchecked, these cause damage to a number of cell components, resulting in tissue death. One target for oxygen radicals are proteins in mitochondria, the powerhouses of the cell that are responsible for meeting cell energy needs. It is well known that the ability of mitochondria to maintain energy supplies decreases in old age. Over the past decade, research has shown t ....During the ageing process and exposure to certain drugs or chemicals, oxygen radicals are produced within cells and tissues. If unchecked, these cause damage to a number of cell components, resulting in tissue death. One target for oxygen radicals are proteins in mitochondria, the powerhouses of the cell that are responsible for meeting cell energy needs. It is well known that the ability of mitochondria to maintain energy supplies decreases in old age. Over the past decade, research has shown that this is partly due to mutation of genes in the DNA which is found in mitochondria. However it is also very likely that the loss of function in mitochondria during the ageing process is also due to the accumulation of protein damage. Recent work in insects has shown that specific proteins in mitochondria are extensively damaged during the ageing process and-or exposure to oxygen radicals. In higher organisms such as mice, however, exactly which mitochondrial proteins are targeted by oxygen radicals is unknown. This work will investigate the likelihood that proteins located in membranes of mitochondria are targets for damage by oxygen radicals and during the ageing process. Furthermore, since oxygen radicals readily attack polyunsaturated fatty acids in cell membranes, we are investigating the likelihood that toxic substances (unsaturated aldehydes) formed during membrane damage contribute to the damage to mitochondrial proteins during the ageing process.Read moreRead less
Gamma-secretase Complex: Molecular Characterization, And Moduation Of Enzymatic Activity
Funder
National Health and Medical Research Council
Funding Amount
$526,517.00
Summary
A small protein fragment terned A-beta accumulates as amyloid plaques in the brain of patients with Alzheimer's disease. A-beta is toxic, it causes degeneration of brain cells, and it is believed to be the primary cause of Alzheimer's disease. Therefore, developing strategies to reduce the amounts of A-beta in the brain constitutes a rational therapeutic approach. A-beta is produced from a precursor protein by two cleaving enzymes that operate in a sequential order: these are termed beta and gam ....A small protein fragment terned A-beta accumulates as amyloid plaques in the brain of patients with Alzheimer's disease. A-beta is toxic, it causes degeneration of brain cells, and it is believed to be the primary cause of Alzheimer's disease. Therefore, developing strategies to reduce the amounts of A-beta in the brain constitutes a rational therapeutic approach. A-beta is produced from a precursor protein by two cleaving enzymes that operate in a sequential order: these are termed beta and gamma-secretases. Gamma-secretase carries out the second and final step in the release of A-beta peptide, and it is a determining factor since it can create A-beta fragments of different lengths and with different toxic properties. Our group studies the biochemical characteristics of gamma-secretase, and the factors that regulate its activity to uncover novel therapeutic leads. In this project we will 1) investigate the molecular composition of gamma-secretase using biochemical methods 2) study the importance of the two components of gamma-secretase, termed APH-1 and nicastrin, for the enzymatic activity 3) analyse the mechanism of mutations in the A-beta precursor protein that occur at or near the gamma-secretase site of cleavage and cause familial Alzheimer's disease 4) search for factors that regulate gamma-secretase activity using a genetic screen approach. The results of the proposed experiments will provide information to help design new therapeutic strategies for Alzheimer's disease, an illness that afflicts a large proportion of the ageing population and places a major socio-economic burden upon our society.Read moreRead less
QUANTITATIVE ASSESSMENT OF LOOSENING IN HIP ARTHROPLASTIES USING MECHANICAL VIBRATION DIAGNOSTICS
Funder
National Health and Medical Research Council
Funding Amount
$185,665.00
Summary
Recent advances and improvements made to the mechanical design of artificial joints have led to greater strength, fatigue life and wear resistance. However, this extension to the working life of joint replacements has led to patients becoming increasingly vulnerable to the problem of joint loosening. There are over 500 000 hip joint replacements performed every year, on a worldwide basis. Of these 7 to 13% will require revision surgery because of loosening at some stage of their working life. Th ....Recent advances and improvements made to the mechanical design of artificial joints have led to greater strength, fatigue life and wear resistance. However, this extension to the working life of joint replacements has led to patients becoming increasingly vulnerable to the problem of joint loosening. There are over 500 000 hip joint replacements performed every year, on a worldwide basis. Of these 7 to 13% will require revision surgery because of loosening at some stage of their working life. This is becoming a major concern to health services around the world since revision surgery is associated with a higher risk to the patient and costs are far greater than for the primary operation. Current diagnostic techniques using radiographic imaging are both invasive and lack diagnostic accuracy. The ability to detect joint loosening and to discriminate between the various causes of joint loosening following arthroplasty is of great importance to the success of subsequent care plans. This study will be the first in the world to assess the validity of a new diagnostic test that uses low energy mechanical vibration to quantify the degree of loosening in both components of the implanted hip joint. Once the technique has been proven it could readily be extended to evaluate the degree of fixation of other implanted prostheses used to replace the knee, ankle or joints of the upper limbs.Read moreRead less
The Leucine Rich Repeat Kinase 1 And 2 Genes Are Modulators Of Alternative Splicing - Implication For Neurodegeneration
Funder
National Health and Medical Research Council
Funding Amount
$583,809.00
Summary
Alzheimer's disease (AD) and Parkinson's disease (PD) are the two common causes of dementia and neurodegeneration. Through positional cloning, we have identified the leucine rich repeat kinase (LRRK1) 1 gene as a modulator of alternative splicing. We have subsequently shown that its homologue, LRRK2 has a similar biological activity. We propose to study the the genetic and biochemical role of LRRK1 and LRRK2 in neurodegeneration in terms of its effect in splicing.