A Novel Cytoskeletal Structure In Muscle Is Associated With Muscular Dystrophy
Funder
National Health and Medical Research Council
Funding Amount
$371,250.00
Summary
A NEW PROTEIN NETWORK IN MUSCLE IS ASSOCIATED WITH MUSCLE DISEASE An intricate protein network connects the contracting mechanism of a muscle to the surrounding cell membrane. Disruption of this connection is one of the known causes of muscular dystrophy. For many patients however the cause of the disease is unknown. We have identified a new region within this protein network that is also associated with muscle disease in mice. A number of proteins that are involved in transmitting chemical mess ....A NEW PROTEIN NETWORK IN MUSCLE IS ASSOCIATED WITH MUSCLE DISEASE An intricate protein network connects the contracting mechanism of a muscle to the surrounding cell membrane. Disruption of this connection is one of the known causes of muscular dystrophy. For many patients however the cause of the disease is unknown. We have identified a new region within this protein network that is also associated with muscle disease in mice. A number of proteins that are involved in transmitting chemical messages from one part of the muscle cell to another are found at this same location. It is possible that disruption of these messages may lead to muscle disease. This project aims to establish the nature of the relationship between the proteins found in this newly identified region of the protein network and muscle diseases such as muscular dystrophy, in both animal models and in humans. We expect that this project may identify new markers for identifying the cause of muscle diseases in some patients and lead to better hopes for an eventual cure.Read moreRead less
Targeting Calcineurin For Improving Muscle Regeneration In Skeletal Muscle Disease
Funder
National Health and Medical Research Council
Funding Amount
$303,000.00
Summary
Muscular dystrophy is a term that covers a diverse group of inherited disorders characterised by progressive muscle weakness and wasting. Duchenne muscular dystrophy (DMD) is the most severe form, caused by a lack of a protein called dystrophin, which renders muscles fragile, susceptible to damage, and with a compromised ability to regenerate or repair after injury. The disease progresses to all muscles and DMD patients are dependent on a wheelchair before their early teens and die in their twen ....Muscular dystrophy is a term that covers a diverse group of inherited disorders characterised by progressive muscle weakness and wasting. Duchenne muscular dystrophy (DMD) is the most severe form, caused by a lack of a protein called dystrophin, which renders muscles fragile, susceptible to damage, and with a compromised ability to regenerate or repair after injury. The disease progresses to all muscles and DMD patients are dependent on a wheelchair before their early teens and die in their twenties. There is a profound need for treatments that can ameliorate the dystrophic condition and improve patient quality of life. Restoring or increasing a muscle's capacity to regenerate would help improve muscle function. We have convincing evidence that the calcineurin signal transduction pathway is important for successful muscle regeneration in mice with muscular dystrophy. There is growing excitement worldwide that stimulating calcineurin could attenuate the dystrophic pathology, however, little is known about the role of calcineurin signalling in human muscle disease. Our goals are to investigate the role of calcineurin signalling in muscular dystrophy and to examine its therapeutic potential for enhancing muscle regeneration. Our aim is to better understand the mechanisms controlling calcineurin signalling in muscles of dystrophic mice and in muscles of patients with DMD. A comprehensive series of physiological, molecular, biochemical, and immunohistochemical experiments will be performed to rigorously test our research aim. Understanding the role of the calcineurin pathway in muscle regeneration is important for the development of novel therapeutic strategies to delay the onset or slow the progression of muscle wasting and weakness. The findings will have broad clinical application for our understanding of muscular dystrophy with relevance to other conditions including ageing, AIDS, burns, cancer cachexia, and disuse atrophy, where muscle wasting occurs.Read moreRead less
Targeting Beta-adrenergic Signalling To Improve Muscle Regeneration In Muscular Dystrophy
Funder
National Health and Medical Research Council
Funding Amount
$473,224.00
Summary
Duchenne muscular dystrophy (DMD) is the most common and severe form of muscular dystrophy, caused by a lack of a protein called dystrophin. Dystrophic muscles are fragile, prone to injury, and have a compromised ability to regenerate after damage. Modulating pathways regulating beta-adrenergic signalling has potential to attenuate the dystrophic pathology and to delay the onset or slow the progression of the muscle wasting and weakness in muscular dystrophy.
Molecular Mechanisms Of Collagen Matrix Assembly In Health And Disease
Funder
National Health and Medical Research Council
Funding Amount
$1,171,996.00
Summary
This project studies the way the specific protein building blocks of tissues interact with each other to form the complicated structural networks necessary for tissue growth, development and function. Specifically, we will study collagens, the main structural proteins of the body. We will determine how they assemble with other proteins to form the complex fibrils or molecular ropes, which provide mechanical strength to tissues and create the environment for cells to grow and develop in tissues s ....This project studies the way the specific protein building blocks of tissues interact with each other to form the complicated structural networks necessary for tissue growth, development and function. Specifically, we will study collagens, the main structural proteins of the body. We will determine how they assemble with other proteins to form the complex fibrils or molecular ropes, which provide mechanical strength to tissues and create the environment for cells to grow and develop in tissues such as bone, skin, cartilage and muscle. We will explore the effect of collagen mutations, that occur in patients with inherited diseases of cartilage and muscle, on these assembly processes. This will provide key information on the disease process, so that in the future new approaches to diagnosis and therapy can be developed. The understanding we gain on the molecular basis of tissue structural assembly from these studies will be of importance for understanding normal tissue growth and development, and for the development of new biomaterials for therapeutic use.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
The Role Of Notch Signalling In Muscular Dystrophy
Funder
National Health and Medical Research Council
Funding Amount
$526,878.00
Summary
Duchenne muscular dystrophy (DMD) is the most common and severe form of muscular dystrophy, caused by a lack of a protein called dystrophin. Dystrophic muscles are fragile, prone to injury, and have a compromised ability to regenerate after damage. Defective Notch signalling has been implicated in the poor regenerative response of aged muscles and similarly in dystrophy based on our preliminary data. Modulating Notch signalling could therefore delay the onset or slow the progression of DMD.
The Role Of Dysferlin In Muscular Dystrophy And Skeletal Muscle Membrane Repair.
Funder
National Health and Medical Research Council
Funding Amount
$316,667.00
Summary
Patients who lack the protein dysferlin have muscular dystrophy. These patients are unable to repair their muscle membranes, which get damaged during normal activities. A defect in membrane repair is a new pathway implicated in the muscular dystrophies, and it is likely that other patients will also have defective muscle membrane repair. We will find out how dysferlin mediates its role in membrane repair, and identify other dysferlin-interacting proteins, as these may also underlie disease.
Targeting The TGF-beta Signalling Pathway To Improve Muscle Growth And Development In Muscular Dystrophy
Funder
National Health and Medical Research Council
Funding Amount
$526,878.00
Summary
Duchenne muscular dystrophy (DMD) is the most common and severe form of muscular dystrophy. Dystrophic muscles are fragile, prone to injury, and do not regenerate well after injury. Modulating cell signalling pathways that are involved in muscle growth has the potential to attenuate the severity of the dystrophic pathology, to delay the onset or slow the progression of the muscle wasting and weakness, and to improve muscle growth and development in muscular diseases.
Role Of Nitric Oxide And Reactive Oxygen Species In Excitation-contraction Coupling In Skeletal Muscle.
Funder
National Health and Medical Research Council
Funding Amount
$163,250.00
Summary
Excitation-contraction (E-C) coupling is a term used to broadly describe the sequence of cellular events that starts with an electrical signal at the surface membrane of a muscle cell and which then ultimately leads to muscle contraction. Although the overall sequence is known, there remain many gaps in our understanding of the mechanisms involved not only related to normal muscle function but to how this function may be impaired by excessive exercise and disease. Many cellular metabolites contr ....Excitation-contraction (E-C) coupling is a term used to broadly describe the sequence of cellular events that starts with an electrical signal at the surface membrane of a muscle cell and which then ultimately leads to muscle contraction. Although the overall sequence is known, there remain many gaps in our understanding of the mechanisms involved not only related to normal muscle function but to how this function may be impaired by excessive exercise and disease. Many cellular metabolites contribute towards the normal control of muscle contraction, while others contribute to its impairment. Reactive oxygen species (ROS), which includes nitric oxide (NO) and related molecules, are metabolic factors often referred to as cellular oxidants. They are thought to have an essential role in controlling normal muscle function. Paradoxically, they are also implicated in the impairment of muscle function associated with fatigue, disease and aging. How these molecules both control normal muscle activity and also contribute to impairment of such function remains unclear. Thus, the central aim of this project is to identify the mechanisms by which the cellular oxidants, NO and other ROS, both control normal E-C coupling in skeletal muscle fibres and how they contribute to muscle fatigue. Clearly, understanding how skeletal muscle normally contracts is essential in order to better understand how muscle function can become impaired with exercise, disease and age. The work from this study will provide insight into both normal muscle physiology and how muscles fatigue and ultimately provide new methodologies and drugs that may combat fatigue, disease and age related changes to muscle function.Read moreRead less