The Role Of The Ras Signalling Molecule, C3G, In The Interaction Of Neural Precursor Cells And Their Environment
Funder
National Health and Medical Research Council
Funding Amount
$319,446.00
Summary
Developmental brain disorders affect 1-3% of the population. The mental retardation disease spectrum includes neuronal migration disorders and neural precursor proliferation disorders. We propose to study a molecular mechanism regulating neuronal migration, survival and proliferation. We have identified a protein, C3G, which is essential for three aspects of nervous system development: (A) C3G limits neural precursor cell proliferation. (B) C3G is essential for neuronal survival. (C) C3G is cruc ....Developmental brain disorders affect 1-3% of the population. The mental retardation disease spectrum includes neuronal migration disorders and neural precursor proliferation disorders. We propose to study a molecular mechanism regulating neuronal migration, survival and proliferation. We have identified a protein, C3G, which is essential for three aspects of nervous system development: (A) C3G limits neural precursor cell proliferation. (B) C3G is essential for neuronal survival. (C) C3G is crucial for neuronal migration. C3G acts in a cascade of proteins, known as the Ras signalling pathway, which transmits signals from the extracellular environment into the cell nucleus to elicit appropriate responses of the cell to cues from the outside. We will identify proteins that, together with C3G, affect the important processes of neural precursor proliferation, and neuron survival and migration. This project will fully characterise a key regulatory mechanism of cellular processes crucial to the development of normal intelligence.Read moreRead less
Shaping the vertebrate brain: defining the cellular and genetic drivers . This project aims to uncover specific cellular and genetic mechanisms that control growth and shape of the brain. How brain shape and size changes during evolution of vertebrates is enigmatic but important to know for better understanding of behaviour and function of intact and diseased brain. The project aims to assemble team of national and international experts to build international capacity and unique genetics model t ....Shaping the vertebrate brain: defining the cellular and genetic drivers . This project aims to uncover specific cellular and genetic mechanisms that control growth and shape of the brain. How brain shape and size changes during evolution of vertebrates is enigmatic but important to know for better understanding of behaviour and function of intact and diseased brain. The project aims to assemble team of national and international experts to build international capacity and unique genetics model to generate new knowledge of the cellular and genetic components that drive evolution of different brain parts and shapes the vertebrate brain. In doing so the project aims to provide research training, excellence and knowledge that in future may benefit health and the society. Read moreRead less
Truncating Presenilin Mutations And Their Effects On Gamma-secretase Activity, Tau And Beta-catenin
Funder
National Health and Medical Research Council
Funding Amount
$414,005.00
Summary
Alzheimer's disease (AD) and cancer are increasingly important both in terms of human suffering and the burden of care it imposes on society and the economy. Sporadic (non-inherited) AD is the most common form of dementia but is poorly understood. The PRESENILIN genes, PSEN1 and PSEN2, are the major sites for mutations causing inherited AD and are also implicated in cancer. Using the zebrafish embryo model we have discovered that, contrary to current thought, mutations that truncate presenilin p ....Alzheimer's disease (AD) and cancer are increasingly important both in terms of human suffering and the burden of care it imposes on society and the economy. Sporadic (non-inherited) AD is the most common form of dementia but is poorly understood. The PRESENILIN genes, PSEN1 and PSEN2, are the major sites for mutations causing inherited AD and are also implicated in cancer. Using the zebrafish embryo model we have discovered that, contrary to current thought, mutations that truncate presenilin proteins potently suppress normal presenilin activity. (They are so called, dominant negatives). This means that they are lethal for embryo development and explains why such mutations have never been found in inherited AD. Notably, this discovery could only be made using a subtle form of gene manipulation that is possible in zebrafish embryos. Our work has also established the first assay for the non-apoptotic (non-cell death) function of PSEN2 and has shown that PSEN2 activity is inhibited by truncated PSEN1. This is the first indication of possible interaction between PSEN1 and PSEN2 proteins at normal physiological expression levels. Loss of presenilin activity promotes cancer. Truncated presenilin proteins could be produced by errors in gene transcription (aberrant transcript splicing) common in cancerous cells. This suggests that truncated, dominant negative forms of presenilin produced through aberrant splicing (or mutation in precancerous cells) might be common in tumour formation. The proposed research will define the region of PSEN1 in which truncation leads to dominant negative activity. This will allow further examination of the role of presenilins in the cell signalling pathways involved in AD and cancer. We will also investigate the role that age-related truncation of presenilins in human cells can play in the formation of sporadic AD. This may reveal a common molecular link between the inherited and sporadic forms of this disease.Read moreRead less
Awaking quiescent neural stem cells. This project aims to generate new knowledge in the area of the evolutionary size of animals and plants, which is determined by intrinsic cell regulation and is constrained by nutrient availability. Brain size is perhaps the most profound example of this. Brain size regulation is underpinned by control of proliferation of neural stem cells (NSCs). Using Drosophila NSCs, the project will examine how nutrients impact on NSC quiescence versus activation, a key ch ....Awaking quiescent neural stem cells. This project aims to generate new knowledge in the area of the evolutionary size of animals and plants, which is determined by intrinsic cell regulation and is constrained by nutrient availability. Brain size is perhaps the most profound example of this. Brain size regulation is underpinned by control of proliferation of neural stem cells (NSCs). Using Drosophila NSCs, the project will examine how nutrients impact on NSC quiescence versus activation, a key characteristic of stem cell control throughout evolution. This will increase our understanding of how energy metabolism and nutrition influence organ size control in multicellular organisms, by determining how organs communicate with each other to convert nutrient signals to action stem cell proliferation.Read moreRead less
Neurons in the two hemispheres of the brain make connections with each other via a large fibre tract called the corpus callosum. In over fifty different human congenital syndromes the corpus callosum fails to form properly. Such syndromes, which include Aicardi syndrome, Andermann syndrome, Shapiro syndrome and Acrocallosal syndrome, can result in mental retardation, seizures, lack of motor coordination and ocular abnormalities in children. Our data on both mouse and human brain development show ....Neurons in the two hemispheres of the brain make connections with each other via a large fibre tract called the corpus callosum. In over fifty different human congenital syndromes the corpus callosum fails to form properly. Such syndromes, which include Aicardi syndrome, Andermann syndrome, Shapiro syndrome and Acrocallosal syndrome, can result in mental retardation, seizures, lack of motor coordination and ocular abnormalities in children. Our data on both mouse and human brain development show that the mouse is an excellent model system for understanding how the brain becomes wired up during development and what may go wrong in these disorders. Here we investigate the role of a family of genes called nuclear factor one (Nfi) genes in brain development. When mutated in mice, members of this gene family, principally Nfia and Nfib, cause severe malformations of the brain. The phenotype inlcudes a failure to form some midline glial populations, the expansion of the cingulate cortex and loss of the corpus callosum. The propoer formation of midline glial populations and the cingulate cortex are essential to callosal fomration and correct brain wiring. Defects in brain wiring in the cingulate cortex during development may underlie disorders such as schizophrenia, bipolar disorder and depression. In this project we will address the mechanism of function underlying the control of brain development by the Nfi genes. The expected outcomes of this research are to identify new mechanisms and genetic pathways critical to the formation of connections between the two sides of the brain and proper formation of the cingulate cortex. These results will improve our understanding of how the brain forms and what mechanisms may be disrupted during development that result in neurological and cognitive deficits in children and adults.Read moreRead less
I work on mitochondrial diseases, which are inherited disorders of metabolism that block conversion of food energy into chemical energy needed by our cells. We focus on understanding (i) the genetic basis of these disorders using approaches such as massively parallel sequencing, systems biology and experimental studies, and (ii) the detailed mechanisms of disease by studying cell lines from patients and animal models. We aim to develop better methods for diagnosis, treatment and prevention.
Cell Type Specification In Developing CNS: Functional Analysis Of Sox14
Funder
National Health and Medical Research Council
Funding Amount
$468,055.00
Summary
The central nervous system (CNS) is the most complex organ in the body. The vast majority of nerve cells in the CNS are classified as 'interneurons'. These cells relay sensory information and motor commands within the CNS. Abnormal functioning of interneurons is likely to be the underlying cause of some, if not many, human nervous system diseases. However, very little is known of the precise anatomy and function of interneurons, which genes control their development, and how these functions are ....The central nervous system (CNS) is the most complex organ in the body. The vast majority of nerve cells in the CNS are classified as 'interneurons'. These cells relay sensory information and motor commands within the CNS. Abnormal functioning of interneurons is likely to be the underlying cause of some, if not many, human nervous system diseases. However, very little is known of the precise anatomy and function of interneurons, which genes control their development, and how these functions are maintained in the adult. This has been largely due to a lack of efficient and reliable methods to identify and study interneurons. We have previously discovered that a gene termed Sox14 is active in distinct interneuron groups in the embryonic brain and spinal cord. Sox14 is a member of the Sox gene family, many of which act as genetic switches to control cell and tissue development. We found that Sox14 has been extremely well conserved throughout evolution and is active in similar interneuron groups in a number of animal species. These studies led us to hypothesise that Sox14 controls a critical molecular step in the generation of certain interneurons that may be involved in reflexes, locomotion or motor coordination. In this project, we will investigate both the role of Sox14 in interneuron development and the functions of interneurons in which this gene is active. We will do so by combining modern molecular and genetic techniques with physiological approaches. This project will reveal critical molecular steps in CNS development and determine the functions of a specific group of interneurons. To this end, we will generate mouse strains in which a specific group of interneurons are genetically marked and can be manipulated during development. We envisage that these mice with 'modified brain circuits' will become unique resources for future investigations of selected interneuron types and their functions.Read moreRead less
Novel Gene Identification And Characterisation In Epilepsy.
Funder
National Health and Medical Research Council
Funding Amount
$303,964.00
Summary
Epilepsy is a serious neurological disorder affecting up to 5% of the population at some point in their lives. Approximately 70% cases of epilepsy are genetic, but very few of the genes involved have been identified. This project will use state-of-the-art techniques to identify genetic mutations causing an inherited form epilepsy affecting infants. This research is expected to reveal new gene families involved in the genesis of epilepsy and thus new targets for the development of treatments.
Sialyltransferase In The Bipolar And Schizophrenic Brain: Examining The Role Of A Novel Generalised Susceptibility Gene
Funder
National Health and Medical Research Council
Funding Amount
$512,627.00
Summary
Bipolar disorder and schizophrenia are two major psychiatric conditions affecting over 800,000 Australians. We have identified a new gene which contributes to increased risk to developing both bipolar disorder and schizophrenia. We will investigate the function of this gene in normal brain development, and how this function is disrupted in individuals with bipolar disorder and schizophrenia. Understanding the biological cause will help us define better treatments for these severe mental illnesse ....Bipolar disorder and schizophrenia are two major psychiatric conditions affecting over 800,000 Australians. We have identified a new gene which contributes to increased risk to developing both bipolar disorder and schizophrenia. We will investigate the function of this gene in normal brain development, and how this function is disrupted in individuals with bipolar disorder and schizophrenia. Understanding the biological cause will help us define better treatments for these severe mental illnesses.Read moreRead less