GENETIC PREDICTION OF FRACTURE IN A RISK-STRATIFIED POPULATION
Funder
National Health and Medical Research Council
Funding Amount
$363,000.00
Summary
Osteoporosis is a condition characterised by excessive bone loss and impaired bone quality, which ultimately results in fracture with minimal trauma. Osteoporosis affects 27% of women and 11% of men aged 60 years or above in the community, and costs Australia around $7 billion each year. Individuals with low bone mineral density (BMD) have a significantly higher risk of fracture than those with normal BMD. In the long-term (14-year) Dubbo Osteoporosis Epidemiology Study, more than half of indivi ....Osteoporosis is a condition characterised by excessive bone loss and impaired bone quality, which ultimately results in fracture with minimal trauma. Osteoporosis affects 27% of women and 11% of men aged 60 years or above in the community, and costs Australia around $7 billion each year. Individuals with low bone mineral density (BMD) have a significantly higher risk of fracture than those with normal BMD. In the long-term (14-year) Dubbo Osteoporosis Epidemiology Study, more than half of individuals with osteoporosis (e.g., low BMD) did not sustain a fracture, while approximately 60% of fracture cases had BMD above the high risk levels. Thus, BMD alone is not a good discriminant of fracture versus non-fracture cases. It is widely known that the liability to fracture is determined in part by genes. Previous studies, including from our group, have suggested a number of candidate genes that are associated with fracture risk. The fundamental issue that this study is concerned is that how and whether genetic markers could be used to facilitate case finding. It is proposed that common variations of certain genes are associated with fracture risk independent of BMD. That is, they can identify individuals at relatively high and low fracture risk after stratification for BMD. Hence, some markers may identify those individuals likely (and unlikely) to fracture even with low (osteoporotic) BMD. Similarly, some, possibly the same, markers may identify individuals at high risk of fracture despite relatively good (ie non-osteoporotic) BMD. It is further proposed that no single gene will achieve this outcome, but rather a small set of such gene polymorphisms will provide clinically useful risk information. This effect is entirely analogous to the use of clinical risk indicators (eg, age, weight, sex, family history, etc) to assess the risk of future fracture.Read moreRead less
Mechanisms Of Premature Cranial Fusion: Role Of Retinol Binding Protein 4 In Osteogenesis And Suture Fusion
Funder
National Health and Medical Research Council
Funding Amount
$555,855.00
Summary
Craniosynostosis is a condition where the skull bones fuse prematurely, affecting skull shape, vision and cognition. It occurs in 1 in 2,500 births. The only treatment is surgery, which is life-threatening, costly and may need to be repeated. By studying how fusion happens in this project we may be able to devise therapies to minimize the risks and need for re-operation. Here, we hope to show that modification of a single substance in the skull of mouse models can prevent premature bone fusion.
How Do Bone-active Drugs Increase Patient Survival?
Funder
National Health and Medical Research Council
Funding Amount
$613,952.00
Summary
Bisphosphonates are a class of drugs used to prevent bone destruction in diseases such as osteoporosis. Evidence is emerging that these drugs also act on cells outside the skeleton to have additional beneficial effects, for example prolonging patient survival. This project will identify the cells affected and the mechanisms involved. With this knowledge, these drugs could be used more effectively and in different ways for the prevention or treatment of cancer and chronic human illnesses.
Determination Of Irradiation Dose Efficacy For Use In Impaction Grafting At Revision Joint Replacement
Funder
National Health and Medical Research Council
Funding Amount
$411,517.00
Summary
Primary hip replacement is a successful intervention for hip disease, but 10-15% of hip prostheses fail and require revision surgery within 10-15 years. At the time of revision, significant bone loss around the failed prosthesis is not uncommon. A bone reconstruction procedure, called impaction grafting, where donor bone is minced and placed in the areas of deficient bone before implanting the new prosthesis, has shown to give good results at more than ten years in some centres. A high incidence ....Primary hip replacement is a successful intervention for hip disease, but 10-15% of hip prostheses fail and require revision surgery within 10-15 years. At the time of revision, significant bone loss around the failed prosthesis is not uncommon. A bone reconstruction procedure, called impaction grafting, where donor bone is minced and placed in the areas of deficient bone before implanting the new prosthesis, has shown to give good results at more than ten years in some centres. A high incidence of early complications of this procedure have included loss of fixation within the bone. Fracture of the bone around prostheses has also reported in some centres. These events require more surgery, putting the patient at higher risk greater complications and longer rehabilitations. Recent improvements in surgical technique and donor bone preparation have improved results. A current debate questions whether the dose of irradiation can be reduced from 25 kGy, while maintaining sterility of allografts. The risk of bacterial contamination in allografts is low, and irradiation reduces the mechanical strength of the graft, contributing to complications when irradiated bone is used. The benefits of decontaminating the bone may be outweighed by the higher risk for failure due to poor bone quality and resulting prosthesis instability. We will use ISO standards to test the validity of radiation dose for sterilising bone ex vivo. In the absence of controlled human studies, our aim is also to compare the results of impaction grafting with non-irradiated bone versus bone irradiated at current doses used by Australian bone banks, and lower doses indicated by ex vivo testing. We will use a large animal model of revision hip replacement, with precise measures of prosthesis stability. The results of this study will guide clinical decisions regarding the efficacy of current bone graft preparation procedures and the use of irradiated bone in human hip replacement surgery.Read moreRead less
Tyrosine Kinase Receptor C-ros-oncogene 1 Mediates Twist-1 Haploinsufficiency Induced Craniosynostosis In Children: A Novel Therapeutic Target
Funder
National Health and Medical Research Council
Funding Amount
$562,863.00
Summary
Children with Saethre-Chotzen syndrome exhibit premature fussed coronal sutures, and other skull/ skeletal malformations. Surgical intervention is the only treatment option to ensure optimal cognitive and skeletal development. Our studies have identified a candidate molecular pathway that regulates bone formation by cranial bone cells from these patients. Targeting these key molecular signalling components with chemical inhibitors will help prevent the premature fusion of cranial sutures.
Role Of IGF Binding Protein-3 (IGFBP-3) And IGFBP-5 As Modulators Of Nuclear Hormone Signalling
Funder
National Health and Medical Research Council
Funding Amount
$465,750.00
Summary
The insulin-like growth factors are small proteins involved in the growth of most tissues. Their actions are regulated by binding to larger proteins (known as IGFBPs) in the bloodstream and outside the cell. However, some IGFBPs are also found inside cells, where they seem to carry out other functions. We believe that two of these binding proteins, IGFBP-3 and IGFBP-5, change the way cells respond to vitamin A and vitamin D. These two vitamins are important in cell growth and in the way certain ....The insulin-like growth factors are small proteins involved in the growth of most tissues. Their actions are regulated by binding to larger proteins (known as IGFBPs) in the bloodstream and outside the cell. However, some IGFBPs are also found inside cells, where they seem to carry out other functions. We believe that two of these binding proteins, IGFBP-3 and IGFBP-5, change the way cells respond to vitamin A and vitamin D. These two vitamins are important in cell growth and in the way certain cells perform specialised functions. In test-tube experiments, IGFBP-3 and IGFBP-5 interact directly with the receptors that regulate the effects of these hormones. If the same thing happens inside the cell, IGFBP-3 and IGFBP-5 could change the way these receptors respond to signals from outside the cell. We will investigate what effect these IGFBPs have in living cells and in whole animals and how this may relate to human disease. If we are able to understand how IGFBP-3 and IGFBP-5 affect the way cells respond to vitamin A and D, then we may be able to develop new ways to treat certain human diseases.Read moreRead less
Functional Effects Of Polymorphic Variation Of The Aromatase (CYP19) Gene On Enzyme Activity:relationship To Disease
Funder
National Health and Medical Research Council
Funding Amount
$237,708.00
Summary
After menopause, oestrogen synthesis changes from an ovarian to an adipose source by concersion of androgens to estrogens, a process catalyzed by aromatase, the product of the CYP19 gene. We will generate mutants of the CYP19 gene that we have previously found in humans by site-directed mutagenesis and observe the effects of these mutants on aromatase function. This research will help with diagnosis and treatment of breast and other cancers and osteoporosis in humans .
Effects Of Fast Versus Slow Weight Loss On Fat, Muscle And Bone In Postmenopausal Women
Funder
National Health and Medical Research Council
Funding Amount
$316,450.00
Summary
Very low energy diets (VLED) are increasingly used to treat obesity. Of concern is the fact that VLED induce adaptive responses that can inhibit loss of, and promote regain of, abdominal fat while decreasing lean body mass, muscle strength and bone density. This project will therefore determine whether VLEDs could have negative effects on body composition that increase the risk of metabolic disease, sarcopenia or osteoporosis, and if so, what mechanisms are involved.
Gene Mining For Novel Molecular Determinants Of The Skeleton
Funder
National Health and Medical Research Council
Funding Amount
$633,447.00
Summary
Musculoskeletal conditions affect over 6 million Australians and research has shown that genetic background strongly influences development of these disorders. This project will identify genes that have a role in controlling bone and joint architecture. Identification of these genes will assist in the development of treatments targeting bone disorders and allow screening for these genes to provide an opportunity for people to take preventative action to improve bone and joint health.
G Protein-Coupled Receptors (GPCRs) form the largest family of receptors and drug targets in living organisms. Currently, the major reason that new drugs fail to reach the clinic is lack of appropriate drug effect (approx. 30%). Thus, we need a better understanding of how GPCRs work and how this relates to disease. Work within my fellowship will address this knowledge gap, using GPCR models that are relevant to treatment of metabolic, inflammatory, cardiovascular and central nervous system disea ....G Protein-Coupled Receptors (GPCRs) form the largest family of receptors and drug targets in living organisms. Currently, the major reason that new drugs fail to reach the clinic is lack of appropriate drug effect (approx. 30%). Thus, we need a better understanding of how GPCRs work and how this relates to disease. Work within my fellowship will address this knowledge gap, using GPCR models that are relevant to treatment of metabolic, inflammatory, cardiovascular and central nervous system disease.Read moreRead less