Role Of Homeobox Gene Nkx2-5 In Heart Development And Congenital Heart Disease
Funder
National Health and Medical Research Council
Funding Amount
$143,250.00
Summary
Congenital abnormalities of the heart occur in ~1 in 100 live births and 1 in 10 still births in Western populations. The genetic pathways underlying cardiac development are now being dissected with increasing vigour in an effort to understand both the morphological progressions and genetic basis of heart defects. Mutations in a cardiac gene called Nkx2-5, which encodes a transcriptional regulatory protein, can cause heart defects in human families and isolated individuals, most predominantly at ....Congenital abnormalities of the heart occur in ~1 in 100 live births and 1 in 10 still births in Western populations. The genetic pathways underlying cardiac development are now being dissected with increasing vigour in an effort to understand both the morphological progressions and genetic basis of heart defects. Mutations in a cardiac gene called Nkx2-5, which encodes a transcriptional regulatory protein, can cause heart defects in human families and isolated individuals, most predominantly atrial septal defect (hole in the heart) associated with an abnormality in electrical activity of the heart. Nkx2-5 is expressed in the precursor cells of the muscle and other lineages that make up the heart in the embryo, then in the muscle layer of the heart throughout foetal and adult life. Mouse hearts that lack the Nkx2-5 gene altogether arrest at an early stage of heart development showing a complete block to ventricular chamber formation. Mice lacking only one copy of the Nkx2-5 gene have ASD and electrical defects, similar to the human disease. Building on these findings we have developed a suite of new genetic reagents with which to gain a deeper understanding of the role of Nkx-5 in development and disease. These include a mouse strain from which Nkx2-5-positive muscle cells can be purified away from other cell types in the heart, and another mouse strain that represents a good model for common congenital heart defects. We will further investigate the role of Nkx2-5 in allocation of cell types in the heart, chamber formation and birth defects using these reagents.Read moreRead less
Identification And Characterisation Of Genes Required For Cardiac Morphogenesis
Funder
National Health and Medical Research Council
Funding Amount
$434,706.00
Summary
The heart is the first organ to become functional as an embryo forms, reflecting its critical role in sustaining life. Mistakes that occur as the heart develops have devastating consequences for an individualĂs survival and health. We have identified two zebrafish mutants with heart defects and, using sophisticated imaging and genetic studies, will investigate these defects and identify the genes responsible. This research will improve our understanding of correct and diseased heart formation.
Examining An Extracellular Matrix Regulator Required For Cardiovascular Development
Funder
National Health and Medical Research Council
Funding Amount
$732,600.00
Summary
Cardiovascular disease (CVD) is the highest cause of death in Australia. Specific genes are required for correct assembly and function of the heart and vessels but disease will result if those genes are defective. To diagnose and treat CVD, we must first understand how these genes function. This project will investigate mouse models with genetic defects resulting in CVD. It will determine how and why the diseases occur and investigate a potential therapeutic option for intervention in CVD.
Understanding The Role That Cellular Hypoxia Plays In Normal Heart Development
Funder
National Health and Medical Research Council
Funding Amount
$522,773.00
Summary
Congenital heart defects (CHD) are the most common type of birth defects, being present in 6 out of every 1000 live births, and 10% of stillbirths. In addition to the danger of death during childhood, such heart defects also increase the risk of heart disease during adulthood. Our research project involves looking for the genetic causes of CHD. We are looking at two genes , called HIF1a and CITED2, for which we already have evidence that they are very important in allowing the heart to form norm ....Congenital heart defects (CHD) are the most common type of birth defects, being present in 6 out of every 1000 live births, and 10% of stillbirths. In addition to the danger of death during childhood, such heart defects also increase the risk of heart disease during adulthood. Our research project involves looking for the genetic causes of CHD. We are looking at two genes , called HIF1a and CITED2, for which we already have evidence that they are very important in allowing the heart to form normally within the embryo. Because the heart is the first organ to form in the embryo (during the first trimester), we cannot use humans to study this process. Instead we have two lines of mice which specifically lack either the HIF1a or CITED2 genes throughout the embryo. Both of these mouse lines have severe heart defects similar to some types of CHD seen in humans. However, removal of either of these genes also causes severe defects in other tissues, complicating our study. To overcome this problem, we will use a slightly different technique to remove either gene specifically in the entire developing heart of the embryo, while leaving the normal gene in the rest of the embryo. Thus we will be able for the first time to study the effects of these genes on the heart alone. We suspect that the defects in the hearts of such embryos will be of a particular sub-type of CHD. If this is true, in the future we hope to be able show that mutation of either of these genes will cause a specific type of human CHD. This will enable genetic screening of families with a history of CHD, assist in genetic counselling, and promote the development of therapies.Read moreRead less
Identifying Genes Required For Vertebral Column And Heart Formation
Funder
National Health and Medical Research Council
Funding Amount
$950,418.00
Summary
Birth defects occur in about 3% of live births. These originate as the embryo forms, and we have previously shown that some of these are caused by gene mutation and/or environmental factors during gestation. However, the origins of many such defects remain unexplained. We will examine the DNA of patients to find gene mutations causing such defects. We will also test if mutations in these genes increase the likelihood of the embryo developing a defect if it is exposed to environmental stressors.
Identifying The Genetic And Environmental Causes Of Congenital Malformation
Funder
National Health and Medical Research Council
Funding Amount
$774,540.00
Summary
Birth defects are common, devastating and costly to families and to society. The cause is unknown in 80% of cases. This research is helping families by finding the gene mutations that cause birth defects. Gene discoveries, in some cases, will highlight environmental factors that are important for normal embryo formation, such as oxygen levels and dietary components. By identifying gene and environmental factors associated with causing birth defects, we hope to ameliorate or prevent many cases.
The Role Of Innate Immune Responses In Cardiac Muscle Regeneration
Funder
National Health and Medical Research Council
Funding Amount
$543,678.00
Summary
Heart attack is a life-threatening disease that damages heart muscle. Zebrafish can naturally restore lost heart muscle after injury, providing a model to understand mechanisms of heart regeneration. Here, we will explore previously uncharacterized events involved in heart regeneration, with particular focus on the immune response. We will study how immune responses are involved in heart muscle regeneration in zebrafish to find new insights for repairing damaged muscle in the human heart.
Identification And Characterization Of The Molecular Mechanisms Of Cardiac Muscle Regeneration Regulated By The Epicardium In Zebrafish
Funder
National Health and Medical Research Council
Funding Amount
$540,772.00
Summary
Heart attack is a life-threatening disease that damages cardiac muscle. The human heart cannot create new muscle after the damage, which partly contributes to the high morbidity and mortality of this disease. Unlike humans, zebrafish, a small tropical freshwater fish, can naturally create cardiac muscle after injury. In this project, we will understand at the molecular level how zebrafish regenerate cardiac muscle, and provide insights for repairing damaged muscle in the human heart.
Birth defects are present in 3% of live births and account for some of the 78% of fetuses lost before birth. The causes of these defects are largely unknown. Some are due to genetic factors, some to environmental stresses, and others to a combination of genetic and environmental influences on fetal development. This research aims to identify the genetic and environmental factors that cause birth defects with the anticipation that the occurrence of birth defects may be reduced.
Modelling The Regulation Of Nephron Number By The Renal Stem Cell Niche.
Funder
National Health and Medical Research Council
Funding Amount
$715,935.00
Summary
Chronic kidney disease is a growing burden to the health system. The long term health of your kidneys is influenced by the number of functional units, nephrons, present in each kidney, a feature that is determined before birth. If we could influence this number, we may be able to reduce the risk of kidney disease in later life for at risk populations, including the Aboriginal community. This study will investigate the stem cells that form the nephrons, how the process occurs and how it can be in ....Chronic kidney disease is a growing burden to the health system. The long term health of your kidneys is influenced by the number of functional units, nephrons, present in each kidney, a feature that is determined before birth. If we could influence this number, we may be able to reduce the risk of kidney disease in later life for at risk populations, including the Aboriginal community. This study will investigate the stem cells that form the nephrons, how the process occurs and how it can be influenced.Read moreRead less