Understanding Skeletal Development: A Non-proteolytic Mechanism Of Aggrecan Resorption In The Growth Plate
Funder
National Health and Medical Research Council
Funding Amount
$563,044.00
Summary
Bone formation requires resorption of a cartilage template. We challenge the dogma that cartilage resorption is only by PROTEASES, and propose instead that GLYCOSIDASES might also be involved. Aims: Demonstrate that chondrocytes release glycosidases that are important for bone formation. Significance: New information for the design of reconstructive therapies for people with congenital and acquired limb deficiencies or inherited disorders such as arthritis and chondrodysplasias may be gained.
Roles Of Injury-induced Inflammatory Response In Regulating Bony Repair At Injured Growth Plate Cartilage
Funder
National Health and Medical Research Council
Funding Amount
$366,301.00
Summary
Children's growth plate cartilage is responsible for bone lengthening. Due to popularity of sports and play, trauma-induced growth plate damage and subsequently bone growth defects are common in children, with up to 30% of growth plate injury cases resulting in growth abnormality, for which the present surgical correction is highly invasive and not fully effective. Although we know that the growth plate injury-induced bone growth defects result from bony repair of the injured growth cartilage, w ....Children's growth plate cartilage is responsible for bone lengthening. Due to popularity of sports and play, trauma-induced growth plate damage and subsequently bone growth defects are common in children, with up to 30% of growth plate injury cases resulting in growth abnormality, for which the present surgical correction is highly invasive and not fully effective. Although we know that the growth plate injury-induced bone growth defects result from bony repair of the injured growth cartilage, we largely don't understand why and how this bony repair occurs. Understanding mechanisms for this faulty bony repair of injured growth plate will be critical prior to effective biological treatments can be developed. Recently, using an injury model in young rats, we found that bony tissue formation at injured growth plate is preceded sequentially by inflammatory, fibrogenic, chondrogenic and osteogenic responses. The inflammatory response is an initial event and our recent studies suggest that inflammatory response recruits inflammatory cells and produces important molecules that could significantly influence subsequent fibrogenic, chondrogenic and osteogenic events leading to the bony repair of the injured growth plate cartilage. The current proposal further addresses roles of the inflammatory response and the molecular pathways of this response in regulating downstream bony repair events. This project will generate novel understanding on the faulty bony repair of injured growth plate, and will provide valuable information for developing cost-effective and simple therapeutic intervention that aims to prevent bony repair and to enhance cartilage regeneration of the injured growth plate in children.Read moreRead less
Influence Of Osteocytes On Anabolic Bone Therapies
Funder
National Health and Medical Research Council
Funding Amount
$586,965.00
Summary
This project seeks to define the influence of changes in gene expression in cells called osteocytes, that exist within the substance of bone. These cells form a communication network within the bones of the skeleton, and appear to influence bone formation; changes in gene expression by these cells could influence the efficacy of current and emerging osteoporosis therapies.
Pathophysiology And Prevention Of Methotrexate Chemotherapy-induced Bone Growth Defects
Funder
National Health and Medical Research Council
Funding Amount
$622,598.00
Summary
Childhood chemotherapy often causes growth arrest, osteoporosis, and fractures in cancer patients and survivors. Using a rat model, this project will study how the most commonly used chemotherapy drug methotrexate causes bone growth defects and examine any protective effects of two natural-derived substances. This work will increase our knowledge on chemotherapy-induced bone growth defects, and will be useful for developing a preventative treatment.
Novel Pathways Involving APC And PAR-2 In Cartilage Degradation In Osteoarthritis
Funder
National Health and Medical Research Council
Funding Amount
$448,834.00
Summary
Loss of the cartilage that normally lines the ends of bones is central to joint failure in arthritis and the need for replacement surgery. There are presently no treatments that stop cartilage breakdown in joint disease. This project investigates the role of a new pathway not previously thought to be active in cartilage, in the progressive damage seen in arthritis. Successful completion of these studies may provide a novel new strategy to treat joint disease.
Role Of The Osteoclast In Endochondral Fracture Repair
Funder
National Health and Medical Research Council
Funding Amount
$310,136.00
Summary
Failure of bone healing leads to significant pain and disability, such that augmentation of fracture repair is a dynamic and important field of study. A full understanding of bone repair is necessary before we can hope to introduce successful therapies. We theorise that by stimulating bone forming cells and inhibiting bone resorbing cells we may be able to provide optimal results. Bone resorbing cells, or osteoclasts, have long been considered essential to the initial stages of bone repair (endo ....Failure of bone healing leads to significant pain and disability, such that augmentation of fracture repair is a dynamic and important field of study. A full understanding of bone repair is necessary before we can hope to introduce successful therapies. We theorise that by stimulating bone forming cells and inhibiting bone resorbing cells we may be able to provide optimal results. Bone resorbing cells, or osteoclasts, have long been considered essential to the initial stages of bone repair (endochondral ossification) during which the early soft cartilaginous callus is replaced by hard mineralised callus. Our preliminary studies lead us to believe that endochondral ossification can indeed proceed without osteoclast activity. If we can safely eliminate osteoclast function early in the early stages of fracture repair, a number of therapeutic options open up for the augmentation of bone healing. The return of osteoclast function is necessary in the long term, so our strategy will also need to take this into account. This study will establish which systems are pivotal in endochondral ossification and therefore which interventions we should explore.Read moreRead less
Regulation Of Bone Dynamics By Osteal Tissue Macrophages (Osteomacs)
Funder
National Health and Medical Research Council
Funding Amount
$741,095.00
Summary
There is a high demand for effective treatments to rebuild and replace lost bone in fracture repair and osteoporosis. We have described a discrete population of macrophages (classically immune defense cells) within the specialized tissues that line bones. We have shown that these bone tissue macrophages have a novel role in promoting the formation of new bone. This project grant will extend these observations and identify the clinical potential of bone tissue macrophages to treat bone disease.
Role Of Bone-associated Macrophages In Bone Remodelling And Bone Disease
Funder
National Health and Medical Research Council
Funding Amount
$564,963.00
Summary
Musculoskeletal diseases, including osteoporosis and osteoarthritis, are a national and international health and research priorities. Over 3 million Australians suffer from arthritis and musculoskeletal conditions and their social and economic impact is expected to dramatically increase in the next 20 years as a result of the aging population. Early diagnosis, prevention and treatment of many musculoskeletal diseases are currently inadequate. Consequently, there is a high demand for effective tr ....Musculoskeletal diseases, including osteoporosis and osteoarthritis, are a national and international health and research priorities. Over 3 million Australians suffer from arthritis and musculoskeletal conditions and their social and economic impact is expected to dramatically increase in the next 20 years as a result of the aging population. Early diagnosis, prevention and treatment of many musculoskeletal diseases are currently inadequate. Consequently, there is a high demand for effective treatment options. This project grant application proposes a novel line of scientific investigation that will provide greater understanding of the contribution of macrophages (a cell type that has important roles in normal tissue maintenance and defense against infection) in bone remodelling and disease. Bone is continuously remodelled and replaced to maintain skeletal strength and mineral metabolism. We have shown that a population of macrophages is intimately associated with bone and propose that these cells play an important part in regulating bone remodelling. Macrophages have been implicated in many diseases that have damaging consequences on bone, including osteoporosis and several forms of arthritis, linking aberrant macrophage function to disease-associated bone damage. This project aims to characterize this population of bone-associated macrophages and determine their ability to influence the function of other cells integrally involved in bone remodelling. We will also undertake studies in animal models to determine whether these cells are required for bone remodelling and-or damage. Detailed description of the novel role of macrophages in bone biology will facilitate the development of superior therapeutics, preventatives and cures for bone diseases.Read moreRead less
Cell Biology Of Stress Fractures: Activation Of Remodelling At Sites Of Non-union
Funder
National Health and Medical Research Council
Funding Amount
$493,817.00
Summary
Stress fractures are debilitating injuries. We characterised a model of stress fractures in rat ulnae, learning that they heal by activated remodelling, that key genes are expressed in a temporal pattern, and that part of the fracture remains un-healed, similar to many clinical cases. Now, we will examine cell localisation of important genes necessary for remodelling, and test the efficacy of different growth factors to activate a healing response in the non-healed section of the fracture.