Dissecting The Role Of Hedgehog Signalling In Chondrogenesis And Skeletal Disease
Funder
National Health and Medical Research Council
Funding Amount
$408,739.00
Summary
There are close to 400 inherited disorders that affect how the skeleton develops, as well as a range of injury and age-related skeletal defects. There is much interest in treating such abnormalities with artificial bone grown outside the body. In order to achieve this aim we must understand all of the processes involved in producing and maintaining bone within the body. We are using both mouse and cell culture models of skeletal development to increase our understanding of these processes.
Understanding Human Dysmorphology Through Analysis Of ENU Mutant Mice
Funder
National Health and Medical Research Council
Funding Amount
$602,501.00
Summary
Birth defects are common and have an enormous impact on both the individual and their family. Birth defects are by definition the products of abnormal development of the embryo. Our research is aimed at identifying the normal mechanisms that usually prevail during development and the disturbances to those mechanisms that result in birth defects. These findings will lead to improved diagnostic, therapeutic and preventative options for families affected by birth defects
Rapid Identification And Characterisation Of Genes Involved In Skeletal Development
Funder
National Health and Medical Research Council
Funding Amount
$550,536.00
Summary
Birth defects are common and have an enormous impact on both the individual and their family. Birth defects are by definition the products of abnormal development of the embryo. Our research is aimed at identifying the normal mechanisms that usually prevail during development and the disturbances to those mechanisms that result in birth defects. These findings will lead to improved diagnostic, therapeutic and preventative options for families affected by birth defects
Defining The Genetic Causes Of The Abnormal Vertebral Segmentation Syndrome, Spondylocostal Dysostosis
Funder
National Health and Medical Research Council
Funding Amount
$476,523.00
Summary
There are many birth defects that cause vertebral malformations along the spinal column. These occur as the embryo develops in utero, during the formation of structures known as somites. Somites also form the ribs, muscle, tendons and dermis. We are studying an example of this type of birth defect called spondylocostal dysostosis (SCD). We have shown that mutations in three different genes cause some cases of this inherited disease in humans. These genes are called DLL3, MESP2 and LFNG. However, ....There are many birth defects that cause vertebral malformations along the spinal column. These occur as the embryo develops in utero, during the formation of structures known as somites. Somites also form the ribs, muscle, tendons and dermis. We are studying an example of this type of birth defect called spondylocostal dysostosis (SCD). We have shown that mutations in three different genes cause some cases of this inherited disease in humans. These genes are called DLL3, MESP2 and LFNG. However, 80% of SCD patients do not have a mutation in any of these genes. Thus we need to discover how these other cases occur. This project uses two strategies in parallel. Firstly, we will analyse large families that have a history of SCD, and use this information to find causative gene mutations. However, a significant proportion of cases occur without family history. To find out what genes are involved in these cases is more difficult. We have created a mutant mouse by specifically deleting the DLL3 gene. This mouse has very similar vertebral malformations to SCD. We will compare embryos from normal and mutant mice to find genes that do not operate normally in the mutant. These genes are candidates for causing SCD, and thus we will screen these genes in human patients for mutations. However, simply finding a change in a candidate gene does not necessarily mean that this is the cause of SCD. To prove this, we have developed several tests to determine if the mutation alters the normal function of the protein encoded by the mutated gene. This work will greatly benefit the future genetic assessment of SCD patients. In addition, by studying our mouse model of SCD, we will gain a greater understanding of how DLL3 functions. This knowledge may be useful in developing stem cell-based therapies that involve the production of specific cell types.Read moreRead less
Investigation Of Delta3 Function And Notch Signalling During Cell Fate Specification In Mouse And Human
Funder
National Health and Medical Research Council
Funding Amount
$221,717.00
Summary
This project seeks to understand how cells within the developing embryo are produced and how they are given a specific identity. These processes often require the cell to make a decision about what type of cell it will become. We are using the Delta3 gene, which is present in humans and in the mouse, as a tool for our investigations. Delta3 is expressed at the surface of the cell and Notch (its receptor) is present on the surface of neighbouring cells. Delta3 on one cell will bind to Notch on th ....This project seeks to understand how cells within the developing embryo are produced and how they are given a specific identity. These processes often require the cell to make a decision about what type of cell it will become. We are using the Delta3 gene, which is present in humans and in the mouse, as a tool for our investigations. Delta3 is expressed at the surface of the cell and Notch (its receptor) is present on the surface of neighbouring cells. Delta3 on one cell will bind to Notch on the neighbouring cell and activates Notch. When Notch is activated in a cell it pushes the cell to make its decision. This project aims to determine what exactly is the function of Delta3 in mammals and how at the level of the individual cell this protein exerts its effects. We have generated a mouse in which the Delta3 gene is no longer active and have observed that embryos do not develop normally. We will explore these defects (which affect the skeleton and the brain) in detail in order to define their origins. We will also use these abnormal mice to identify genes, which require the function of Delta3 for their normal activity. It is not only important to define the function of Delta3 in mammals but also to determine this protein functions. We wish to know how exactly Delta3 interacts with Notch. That is, which part of the Delta3 protein binds to which part of the Notch protein. We can address this by modifying the Delta3 protein in small (but revealing ways) and see if it can still bind the Notch receptor in a cell culture assay. Our studies have relevance to humans because recently it has been shown that Delta and Notch are associated with a human syndrome (spondylocostal dysostosis) in which individuals suffer from abnormal skeletons.Read moreRead less
Functional Screening Of Novel Genes In Craniofacial Development
Funder
National Health and Medical Research Council
Funding Amount
$540,075.00
Summary
Our faces are central to our ability to communicate, feed, breath and interact with each other. Birth defects that impact on the normal development of the face are common and affect not only the child but have a dramatic impact on the child's family as well. The genetic causes of most facial birth defects are unknown. This project will develop a method for determining how development of the face is controlled and will help identify genes that are responsible for facial birth defects.
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.
Skeletal muscle responds to exercise or mechanical load, in a process known as hypertrophy. Hypertrophy is initiated by a population of immature muscle cells known as myoblasts which fuse to form myotubes, and then mature to form muscle fibers (differentiation). Many proteins involved in a cascade of activation and-or deactivation are important for regulating hypertrophy (hypertrophic signaling). Failure of skeletal muscle to induce hypertrophy can lead to muscle degeneration. The FHL proteins a ....Skeletal muscle responds to exercise or mechanical load, in a process known as hypertrophy. Hypertrophy is initiated by a population of immature muscle cells known as myoblasts which fuse to form myotubes, and then mature to form muscle fibers (differentiation). Many proteins involved in a cascade of activation and-or deactivation are important for regulating hypertrophy (hypertrophic signaling). Failure of skeletal muscle to induce hypertrophy can lead to muscle degeneration. The FHL proteins are highly expressed in skeletal muscle. FHL proteins are molecular scaffolds which direct assembly of protein complexes to form the muscle contraction machinery (sarcomere). We propose FHL proteins will initiate-regulate skeletal muscle hypertrophy. Increased levels of FHL1 correlate with skeletal muscle hypertrophy. However, it is unclear if increased FHL1 is alone sufficient to induce hypertrophy directly. We have genetically engineered mice to express elevated levels of FHL1 specifically in skeletal muscles (FHL1 transgenic mice) and these mice show muscle enlargement. FHL1 transgenic mice have larger muscle fibers and are >7-fold stronger than non-transgenic littermates. We are currently examining which cell signaling pathways are affected by elevated FHL1. We are also investigating the role of another family member FHL3 in the differentiation of immature myoblasts, a process essential for both embryonic and postnatal skeletal muscle (hypertrophy) development. In the cell nucleus, FHL2 regulates genes which control cell growth and death and increased nuclear levels of FHL2 been detected in prostate cancer biopsies. Recently we demonstrated that FHL2 binds and is sequestered from the nucleus, by a protein, filamin. We are investigating the FHL2-mediated regulation of genes in human melanoma cells, which due to gene mutation are devoid of filamin and will determine how this affects FHL2 function in muscle.Read moreRead less
Identification Of The Molecular Mechanisms By Which Mutations In FHL1 Lead To Protein Misfolding And Skeletal Muscle Disease
Funder
National Health and Medical Research Council
Funding Amount
$609,424.00
Summary
Skeletal muscle diseases result in debilitating muscle loss and may result from an error (mutation) within a gene. Mutations in FHL1 were identified as the cause of four different muscle diseases. Using purified FHL1, skeletal muscle cells and animal models we will investigate how FHL1 mutations cause muscle wasting, and loss of muscle strength.