STUDIES OF NF-E4, A NOVEL FETAL/ERYTHROID SPECIFIC FACTOR INVOLVED IN FETAL GLOBIN GENE REGULATION
Funder
National Health and Medical Research Council
Funding Amount
$753,810.00
Summary
Sickle cell anemia and thalassemia are the commonest genetic disorders worldwide. Those affected suffer devastating clinical sequelae and mortality in the first twenty years of life remains high. A cure for these diseases is dependent on the replacement of the affected or absent hemoglobin protein chains with normally functioning hemoglobins. This is evident in rare patients who co-inherit a natural mutation which elevates fetal hemoglobin (HbF), as these patients have a dramatically ameliorated ....Sickle cell anemia and thalassemia are the commonest genetic disorders worldwide. Those affected suffer devastating clinical sequelae and mortality in the first twenty years of life remains high. A cure for these diseases is dependent on the replacement of the affected or absent hemoglobin protein chains with normally functioning hemoglobins. This is evident in rare patients who co-inherit a natural mutation which elevates fetal hemoglobin (HbF), as these patients have a dramatically ameliorated clinical course. Therefore, treatment strategies which could reactivate fetal globin gene expression after birth should be explored for these diseases. To achieve this goal we must further our understanding of the normal mechanisms of developmental regulation of globin gene expression. To this end we have recently identified a novel gene which is critical for fetal globin expression. The studies we propose here will further define the function of this gene and assess its potential for gene therapy for sickle cell disease and thalassemia.Read moreRead less
Inherited disorders of the blood, such as sickle-cell anaemia and thalassaemia, result from mutations in the genes that produce haemoglobin. Current treatments can partially alleviate some of the debilitating symptoms of these diseases but these treatments have significant side effects, and despite the best efforts of clinicians, many patients succumb to their conditions at an early age. It has been observed that certain individuals exhibit a milder form of the disease, as a consequence of the r ....Inherited disorders of the blood, such as sickle-cell anaemia and thalassaemia, result from mutations in the genes that produce haemoglobin. Current treatments can partially alleviate some of the debilitating symptoms of these diseases but these treatments have significant side effects, and despite the best efforts of clinicians, many patients succumb to their conditions at an early age. It has been observed that certain individuals exhibit a milder form of the disease, as a consequence of the reactivation of their foetal haemoglobin genes, (a distinct set of genes that would have been active in utero but are normally silenced around the time of birth). It is widely accepted that if pharmaceutical means can be found for reactivating the foetal haemoglobin genes then many patients would benefit. The regulation of the foetal globin genes, like most human genes, is complicated and there are few obvious means of increasing their activity. Nevertheless, it is believed that by investigating the molecular mechanisms by which they are controlled it will be possible to devise therapeutic agents that mimic these mechanisms or to develop agents that prevent the shutdown of the foetal genes around birth. To this end we have been working on the molecules that regulate the activity of the haemoglobin genes. We have recently cloned a number of DNA-binding proteins, and their co-factors, that appear to be involved in silencing foetal globin gene expression. This grant proposal is concerned with learning how these new molecules operate to silence gene expression as a first step towards designing agents that will prevent the silencing.Read moreRead less
Functional Characterisation Of Regulators Of Human Globin Gene Switching
Funder
National Health and Medical Research Council
Funding Amount
$232,131.00
Summary
Red blood cells produce haemoglobin, a tetramer of two alpha globin chains and two beta-globin chains. Haemoglobin reversibly interacts with oxygen in such a way that it efficiently shuttles oxygen between the lungs and the rest of the body. Integrity of the hemoglobin molecule, and red cells which carry it, is essential for life of all organisms with blood. The alpha-globin and beta-globin chains that make up haemoglobin are prodcued by red cell precursors in the bone marrow according to the ge ....Red blood cells produce haemoglobin, a tetramer of two alpha globin chains and two beta-globin chains. Haemoglobin reversibly interacts with oxygen in such a way that it efficiently shuttles oxygen between the lungs and the rest of the body. Integrity of the hemoglobin molecule, and red cells which carry it, is essential for life of all organisms with blood. The alpha-globin and beta-globin chains that make up haemoglobin are prodcued by red cell precursors in the bone marrow according to the genetic blueprint (genes) that are inherited. Genetic disorders resulting from defects in the beta-globin gene are the most common inherited disorders of man. Children who fail to make beta-globin have a disease known as beta-thalassaemia. They are transfusion dependent from ~ 6 months of age and need intensive chelation therapy (infusions) to avoid the serious consequnces of iron overload. The average life expectancy in Western cultures is ~ 30 years. There is no cure. In third world countries where a reliable blood supply is unavailable, death occurs earlier. Patients are aften infected with blood born viruses such as hepatitis B, hepatitis C and the AIDS virus, HIV. Sickle cell anaemia is also a very common disease. It is due to a single DNA base mutation at in the beta-globin gene that results in production of normal amounts of a defective beta-globin molecule (HbS). In low oxygen, HbS molecules polymerize in red cells and irreversibly damage them. These red cells get trapped in small blood capillaries throughout the circulation causing small infarcts which results in severe pain and organ damage. The life expectancy is <2 years in the thrid world and ~20-30 years in the west. The irony of these two diseases is that there is a perfectly normal fetal globin gene that has been silenced during fetal life. This grant aims to understand the mechanism of the switch from fetal to adult globin gene usage so it can be reversed in adults with b-thalassemia and sickle cell diseaseRead moreRead less
Oxidative Damage and Cell Ageing. This research will benefit Australia by providing a fundamental understanding of how cells age. This will have immediate international impact at the scientific level and will inform strategies to reduce the rate of ageing and alleviation of age-related disorders. In the longer term the research may provide commercial and social outcomes by identifying antioxidant systems that will provide a genuine benefit in reducing ageing.
Cellular Responses to Oxidative Damage: Cell Aging. The aim of this project is to identify the mechanisms by which oxidative stress and free radical damage cause cell aging. This work will make a significant contribution to our understanding of the aging process in cells by identifying the major reactive oxygen species that contribute to cell aging, which defence systems and antioxidants provide the greatest degree of protection, what damage accumulates as cells age and which genetic systems ar ....Cellular Responses to Oxidative Damage: Cell Aging. The aim of this project is to identify the mechanisms by which oxidative stress and free radical damage cause cell aging. This work will make a significant contribution to our understanding of the aging process in cells by identifying the major reactive oxygen species that contribute to cell aging, which defence systems and antioxidants provide the greatest degree of protection, what damage accumulates as cells age and which genetic systems are activated as during the process.Read moreRead less
CesA (cellulose synthase) genes of Arabidopsis; all doing the same job or specialists cooperating to make the most abundant biopolymer. The biosphere makes more cellulose than any other polymer with fibre industries depending on its physical properties and atmospheric carbon dioxide levels depending on its stability as a carbon sink. Demonstrations that cellulose production needs CesA genes drove recent progress in elucidating the mechanism of synthesis. CesA proteins all look very similar but i ....CesA (cellulose synthase) genes of Arabidopsis; all doing the same job or specialists cooperating to make the most abundant biopolymer. The biosphere makes more cellulose than any other polymer with fibre industries depending on its physical properties and atmospheric carbon dioxide levels depending on its stability as a carbon sink. Demonstrations that cellulose production needs CesA genes drove recent progress in elucidating the mechanism of synthesis. CesA proteins all look very similar but if all do the same job, why do plants need so many and why do none seem redundant? We will make gene interchanges in transgenic plants, build chimeric genes and identify where each CesA protein operates. This will identify their individual and cooperative contributions to cellulose production.Read moreRead less
Function of a new splicing factor, RBM4. New genomic knowledge is revolutionizing our world. However our understanding of the basic mechanisms of RNA maturation, especially regulation of splicing lags significantly behind our understanding of related genomic processes. This project is a genetic approach to help elucidate the function of new splicing factors and characterize the way in which specific RNA sequences are recognized. It should promote the better understanding of regulatory events inv ....Function of a new splicing factor, RBM4. New genomic knowledge is revolutionizing our world. However our understanding of the basic mechanisms of RNA maturation, especially regulation of splicing lags significantly behind our understanding of related genomic processes. This project is a genetic approach to help elucidate the function of new splicing factors and characterize the way in which specific RNA sequences are recognized. It should promote the better understanding of regulatory events involved in controlling gene expression during development and differentiation. Results from this project will also provide new insights into the 'multifunctionality' of cellular proteins and will illustrate the importance of RNA studies in molecular medicine.Read moreRead less
Genetic analysis of cohesin function and regulation in Drosophila. In yeast, a multiprotein complex, called cohesin, holds newly replicated chromatids together until the cell is ready to partition each chromatid into its daughter cells. We and others have shown that cohesins are regulated differently in animal cells. We propose to combine classical genetic analyses with two new and innovative techniques, time-lapse confocal microscopy of fluorescent proteins in living cells and gene-specific kno ....Genetic analysis of cohesin function and regulation in Drosophila. In yeast, a multiprotein complex, called cohesin, holds newly replicated chromatids together until the cell is ready to partition each chromatid into its daughter cells. We and others have shown that cohesins are regulated differently in animal cells. We propose to combine classical genetic analyses with two new and innovative techniques, time-lapse confocal microscopy of fluorescent proteins in living cells and gene-specific knockout techniques to study key cohesin regulators in Drosophila. These studies will provide us with novel insights into how multicellular organisms regulate the structure and stability of their chromosomes.Read moreRead less
Proteomic and Transcriptional Profiling of Cartilage. Gene expression and signalling pathways that regulate cartilage formation, and its orderly transition to bone, are poorly described. Our studies will, for the first time, combine two complementary cutting-edge approaches, protein identification by proteomic analysis, and mRNA profiling by microarray analysis, to define these pathways and develop a comprehensive catalogue of proteins and gene expression patterns during cartilage development a ....Proteomic and Transcriptional Profiling of Cartilage. Gene expression and signalling pathways that regulate cartilage formation, and its orderly transition to bone, are poorly described. Our studies will, for the first time, combine two complementary cutting-edge approaches, protein identification by proteomic analysis, and mRNA profiling by microarray analysis, to define these pathways and develop a comprehensive catalogue of proteins and gene expression patterns during cartilage development and bone formation. This information will provide insight into the regulation of cartilage differentiation, maturation and structure, and will provide a critical platform for the development of more sophisticated cartilage and bone biomaterials for improved tissue repair and regeneration.Read moreRead less