In type 1 diabetes the body becomes deficient in insulin production from pancreatic b cells because the immune system mistakenly attacks and destroys b cells as if they were an invading infection. Recurrence of autoimmune destruction of b cells also occurs following transplantation of whole pancreas or islet cells and may occur in the future when other engineered insulin producing cells are transplanted. The focus of this program is to better understand how b cells are killed by the immune syste ....In type 1 diabetes the body becomes deficient in insulin production from pancreatic b cells because the immune system mistakenly attacks and destroys b cells as if they were an invading infection. Recurrence of autoimmune destruction of b cells also occurs following transplantation of whole pancreas or islet cells and may occur in the future when other engineered insulin producing cells are transplanted. The focus of this program is to better understand how b cells are killed by the immune system and to test ways of protecting beta cells from these mechanisms. Because of the inaccessibility of the pancreas to study (particularly biopsy) in humans with diabetes, much of the proposed work will be carried out in b cells derived from non-obese diabetic (NOD) mice, the best available mouse model of type 1 diabetes. It is clear from the literature that a molecule called perforin found in cytoxic T lymphocytes (CTL) is a major, if not the major, mechanism the immune system uses against b cells. For this reason we will try to better understand the interaction between b cells and perforin and ultimately design ways of them from perforin-mediated cell death. It is equally clear that there are other mechanisms besides perforin that can cause b cell death and the program will also address discovery of these mechanisms and new ways to block them. Beta cells in NOD mice will be protected from perforin or other mechanisms by the addition of protective genes or removal of harmful genes using transgenic knockout technology. Addition or removal of genes involved in cell death can be done systematically and each protocol tested using NOD mouse model. The process of cell death that b cell undergo in type 1 diabetes is called apoptosis. Apoptosis is a general mechanism by which cells of all types die. Experts in the biology of apoptosis and perforin are important members of the program, providing the opportunity to translate the latest advances in cell death research to diabetes. This research addresses several of the specific research areas of interest to JDRF. It focuses on the prevention of b cell death in individuals with type 1 diabetes receiving islet transplants. It may be applicable in the future to protection of stem or precursor cells that have been differentiated into b cells or even to devising strategies to prevent the development of diabetes.Read moreRead less
Building a death-defying islet beta cell Type I diabetes results when the cells that produce insulin (the islet beta cells) are killed by the immune system. The beta cell, like any other cell in the body, can be induced to die by activation of a process that leads to cell suicide. During this process, enzymes dismantle the structure of the cell and the remains are eaten by neighboring cells. In diabetes, the stimulus for beta cell suicide is provided by a number of agents most of which are made ....Building a death-defying islet beta cell Type I diabetes results when the cells that produce insulin (the islet beta cells) are killed by the immune system. The beta cell, like any other cell in the body, can be induced to die by activation of a process that leads to cell suicide. During this process, enzymes dismantle the structure of the cell and the remains are eaten by neighboring cells. In diabetes, the stimulus for beta cell suicide is provided by a number of agents most of which are made by the T cells of the immune system. Our aim is to interfere with this cell suicide process and engineer a beta cell that can resist T cell attack. Because genetically manipulated mice provide the flexibility we need to add and subtract genes from the beta cell we will use them as a model to build a death-defying beta cell. We will investigate three strategies. Firstly, cells will be engineered to express a molecule (CD30 ligand) which recognizes a protein on the surface of the attacking T cells and in so doing, sends a signal to the T cells to stop proliferating. Secondly, we will remove proteins (CD95, TNFRI) from the surface of the beta cell, that attacking T cells use to set in motion the cell suicide process. Thirdly, we will engineer beta cells that express inside themselves, cell death inhibitor proteins (Bcl-2, CrmA, p35) that can prevent the automatic process of cell suicide. It is our hope that studies with death-defying beta cells will find a new way to manipulate islet tissue for transplantation. In patients with diabetes, the beta cells have all been destroyed but the attacking T cells still remain. As a result, transplants of new beta cells are rapidly damaged. Beta cells that can resist ongoing immune attack may survive well enough to reverse the symptoms of diabetes. The success of this research could have an impact on a cure for diabetes.Read moreRead less
Cancers arise as a result of the impairment of critical cellular processes following the mutation of important regulatory genes. I am a molecular biologist and I study how the proteins of the Bcl-2 family regulate apoptosis, a process of cell death essential to maintain homeostasis in multicellular organisms, with the aim of designing drugs to kill cancer cells selectively. I am also interested in discovering new genes involved in the development of cancer using new genomics technology.
Wounds, burns and scalds are frequent injuries which can lead to deformity, disfigurement and loss of movement. We have shown that the cytoskeletal protein, Flightless I (FliI), is an important regulator of wound repair. We plan to further investigate FliI in wound and burn injuries using new cell-specific transgenic animal models and to develop a new FliI-antibody based therapy to treat wound and burn injuries.
Inherited Muscle Disorders - Gene Discovery, Pathobiology And Therapy.
Funder
National Health and Medical Research Council
Funding Amount
$1,750,277.00
Summary
The project proposed by Professors Nigel Laing and Kathryn North and Dr Kristen Nowak is based upon the results of their successful identification of disease genes for genetic muscle diseases. The project is divided into three parts. In the first part of the project, the research team will identify further novel disease genes, some of which they are already close to finding. In the second part of the project the team will determine how the mutations they have identified in the disease genes actu ....The project proposed by Professors Nigel Laing and Kathryn North and Dr Kristen Nowak is based upon the results of their successful identification of disease genes for genetic muscle diseases. The project is divided into three parts. In the first part of the project, the research team will identify further novel disease genes, some of which they are already close to finding. In the second part of the project the team will determine how the mutations they have identified in the disease genes actually cause the diseases. The aim of this work is to discover targets that may ultimately lead to new therapies for these muscle diseases. In the third and final part of the project, the team will pursue one possible therapeutic approach, which is based upon the understanding of the diseases the researchers have gained from their previous studies. There are currently no cures for these muscle diseases, though symptoms can be treated. The team will determine whether heart actin can replace muscle actin in skeletal muscle and thus might treat the muscle disease.Read moreRead less
Novel Features And Mechanisms Of Congenital Myopathies
Funder
National Health and Medical Research Council
Funding Amount
$464,500.00
Summary
Congenital myopathies are inherited diseases of skeletal muscle that typically present at birth or in early childhood and are characterised by poor muscle tone and muscle weakness. This group of disorders includes nemaline myopathy, central core disease, congenital fiber type disproportion, and myotubular myopathy. All of these disorders are characterised by disorganisation of the sarcomere, the major structure within skeletal muscle cells that is involved in contraction. In addition, the congen ....Congenital myopathies are inherited diseases of skeletal muscle that typically present at birth or in early childhood and are characterised by poor muscle tone and muscle weakness. This group of disorders includes nemaline myopathy, central core disease, congenital fiber type disproportion, and myotubular myopathy. All of these disorders are characterised by disorganisation of the sarcomere, the major structure within skeletal muscle cells that is involved in contraction. In addition, the congenital myopathies have features in common with virtually all muscle diseases such as slow fibre predominance and alterations in contractile force. We are using nemaline myopathy as a representative congenital myopathy to examine features in common amongst the myopathies, characteristic of the congenital myopathies and specific to nemaline myopathy. In nemaline myopathy patients, mutations have been found in five genes that encode proteins of the filamentous systems of the sarcomere. A feature specific to nemaline myopathy is the presence of abnormal structures of the sarcomere called nemaline rods. We have analysed a large number of nemaline myopathy patients that have mutations in the genes that encode the filament proteins alpha-skeletal actin and tropomyosin. In addition, we have generated mouse models for nemaline myopathy and propose to generate an additional one with novel features. Our mouse model has revealed that a feature previously thought exclusive to dystrophies, is also present in nemaline myopathy. The combined analysis of well-characterised patient samples and mouse models will allow us to address longstanding questions about this particular congenital myopathy and myopathies in general. We will determine how rods form and their protein composition. Our mouse models in particular will allow us to address the molecular mechanisms that underpin the increase in slow twitch fibres and the effects that a particular mutation has on muscle function.Read moreRead less
Characterisation Of A Novel Family Of Skeletal Muscle Gene Regulators
Funder
National Health and Medical Research Council
Funding Amount
$443,250.00
Summary
Muscle cells may be broadly divided into two classes, slow- or fast-twitch, with different physiological and biochemical properties. These properties are largely determined by the protein products of several multi-gene families that encode the contractile apparatus characteristic of muscle cells. The pattern of expression of these muscle-specific genes defines a muscle cell as either a slow-twitch or fast-twitch myofibre. Skeletal muscle is inherently plastic in its ability to express different ....Muscle cells may be broadly divided into two classes, slow- or fast-twitch, with different physiological and biochemical properties. These properties are largely determined by the protein products of several multi-gene families that encode the contractile apparatus characteristic of muscle cells. The pattern of expression of these muscle-specific genes defines a muscle cell as either a slow-twitch or fast-twitch myofibre. Skeletal muscle is inherently plastic in its ability to express different genes in response to altered functional demand, and under certain circumstances, fibres can convert from one type to another. Conditions known to cause myofibre conversion in humans include congenital myopathies, spinal injury, and exercise. We have identified a novel family of proteins that regulate the genes that confer fibre type. In this proposal, we will further characterise the function of each of these proteins in skeletal muscle development and fibre determination. In addition, the gene that encodes these proteins is one of many deleted in the human condition Williams-Beuren Syndrome (WBS). WBS is characterised by supravalvular aortic stenosis (SVAS), neurological and cognitive defects, infantile hypercalcemia, dental malformations, musculoskeletal anomalies and growth retardation with short stature. The musculoskeletal anomalies, including joint contractures, muscular pain and kyphoscoliosis, cause WS patients to lack stamina and fatigue easily. An underlying myopathy has been reported and may account for the physical limitations, however the disease causing gene-genes have not been identified. We predict that a lack of the MusTRD proteins contributes to these conditions. In general, the findings from our study will yield insights that will lead to improved treatments of patients who suffer from muscle disease or have sustained a nerve injury and improved approaches to excercise training.Read moreRead less
THE ROLES OF CYTOSKELETAL PROTEINS IN SKELETAL MUSCLE FUNCTION AND DISEASE
Funder
National Health and Medical Research Council
Funding Amount
$466,650.00
Summary
Congenital myopathies are inherited diseases of skeletal muscle that typically present at birth or in early chilhood and are characterised by poor muscle tone and muscle weakness. This group of disorders includes nemaline myopathy, central core disease, congenital fiber type disproportion, and myotubular myopathy. All of these disorders are characterised by disorganisation of the sarcomere, the major structure within skeletal muscle cells that is involved in contraction. In nemaline myopathy pat ....Congenital myopathies are inherited diseases of skeletal muscle that typically present at birth or in early chilhood and are characterised by poor muscle tone and muscle weakness. This group of disorders includes nemaline myopathy, central core disease, congenital fiber type disproportion, and myotubular myopathy. All of these disorders are characterised by disorganisation of the sarcomere, the major structure within skeletal muscle cells that is involved in contraction. In nemaline myopathy patients, mutations have been found in five genes that encode proteins of the filamentous systems of the sarcomere. Therefore, the genes for other thin filament, thick filament and Z-line proteins are excellent candidates for these disorders. Research from our lab has identified a novel region of the sarcomere and the genes encoding the proteins present in this region provide additional candidates for the congenital myopathies. We will further characterise the proteins in this novel structure to determine its function and the role that it plays in muscle disease pathologies. In order to study the relationship between disease pathology and muscle weakness in nemaline myopathy, we generated a mouse model by expressing a mutant protein, a-tropomyosin slow, found in human patients in mice. All features of the disease found in humans are present in the mice. A key feature of this disease in mice is the ability for muscle cells to grow in diameter or hypertrophy to offset the muscle weakness. We will use these mice to trial therapies including hypertropy-inducing agents, to prevent and reverse muscle weakness. In addition, we will generate an additional mouse model for this disease with a mutation in a gene encoding another filamentous protein. A comparison of the two models using microarray analysis will help us identify additional genes that are being affected in this disease and to generate a molecular expression profile that will aid in the diagnosis of this disease.Read moreRead less
Vitamin D Synthesis Within Osteoblasts Increases Bone Mineral By Regulating Remodelling: Is This The Link Between Vitamin D Status And Fractures?
Funder
National Health and Medical Research Council
Funding Amount
$627,082.00
Summary
This project will contribute to understanding mechanism of vitamin D action within bone to modulate bone resorption and offers the exciting prospect of identifying the mechanism by which an adequate vitamin D status can reduce the risk of osteoporotic hip fractures. Thus, this project has great potential to improve community health by being able to recommend vitamin D supplementation made on the basis of maintaining normal bone cell function with psarticular reference to modulating bone resorpti ....This project will contribute to understanding mechanism of vitamin D action within bone to modulate bone resorption and offers the exciting prospect of identifying the mechanism by which an adequate vitamin D status can reduce the risk of osteoporotic hip fractures. Thus, this project has great potential to improve community health by being able to recommend vitamin D supplementation made on the basis of maintaining normal bone cell function with psarticular reference to modulating bone resorption.Read moreRead less
Uncovering The Basis Of Inflammatory And Immunodeficiency Diseases
Funder
National Health and Medical Research Council
Funding Amount
$15,718,075.00
Summary
A world-class team from 3 institutions, spanning disciplines of clinical and experimental immunology, therapeutics, signalling and genetics, will identify how immune and inflammatory responses are controlled in both health and disease. The major outcomes of this work will be the generation of new knowledge, concepts and approaches to diagnose, prevent and treat the major human health problems of autoimmune diseases, inflammation, allergy and immunodeficiency.