Cellular Microenvironments Facilitating The Replication And Propagation Of Flaviviruses
Funder
National Health and Medical Research Council
Funding Amount
$505,279.00
Summary
Flaviviruses are the agents of many mosquito-transmitted infections and many deaths globally each year. The emerging virus West Nile virus (strain New York) is a member of this virus family and shares 99% amino acid homology with the endemic Australian virus Kunjin virus. During virus growth in cells, cellular membrane structures are induced or rearranged by these viruses for their own purpose. That being the production of more virus particles for reinfection of other cells. Using Kunjin virus a ....Flaviviruses are the agents of many mosquito-transmitted infections and many deaths globally each year. The emerging virus West Nile virus (strain New York) is a member of this virus family and shares 99% amino acid homology with the endemic Australian virus Kunjin virus. During virus growth in cells, cellular membrane structures are induced or rearranged by these viruses for their own purpose. That being the production of more virus particles for reinfection of other cells. Using Kunjin virus as a model, and advanced techniques in biochemistry and electron microscopy, we have identified for the first time these membrane structures as the apparent sites of replication of the viral RNA or genetic material, and of the viral proteins involved. We have also observed how new virus particles are able to get out of infected cells and shown how some drugs can prevent this occurring thus limiting their transmission. This research will focus on how the membrane structures are formed in infected cells. The research will determine what cellular components are required by the virus to help it propagate. In particular specific cellular proteins and membrane components that are captured by the virus and moved to different sites in the infected cells. These apparent requirements could possibly lead us to a greater understanding of the complex interactions that occur between the invading virus and the host cells. We aim to directly visualize the process of infection within living cells using new and innovative microscopic techniques. Another of our objectives is to determine the effects of infection on normal cells. The question being whether flavivirus infection disrupts normalcell fuctions like secretion etc. An understanding of these processes, and how the viral RNA is copied into new RNA for more virus particles, will assist in the development of antiviral drugs for treatment of this pathogenic group of viruses.Read moreRead less
The Role Of Seipin In Lipid Metabolism And Adipogenesis
Funder
National Health and Medical Research Council
Funding Amount
$397,749.00
Summary
The prevalence of obesity and its related disorders has reached an alarming level in Australia and other developed countries. Obesity is characterized by accumulation of fully-differentiated adipocytes loaded with lipid droplets (LDs). Therefore, understanding the cellular dynamics of LDs and the molecular mechanisms of adipogenesis (adipocyte differentiation) is of crucial importance in our battle against obesity. Our proposed study will help undertand the mechnisams of obesity.
Lipoprotein Metabolism And Mutations Of The APOB Gene Causing Familial Hypobetalipoproteinaemia
Funder
National Health and Medical Research Council
Funding Amount
$396,179.00
Summary
Cardiovascular disease is an increasing problem in Australia, however, the cause of atherosclerosis is incompletely understood. A protein, known as apolipoprotein (apo) B, plays a central role in lipoprotein metabolism. Elevated levels of apoB are characteristic of many forms of hypercholestrolaemia. Familial combined hyperlipidaemia and polygenic hypercholesterolaemia are two common inherited disorders of lipoprotein metabolism that are characterised by elevated apoB levels in the blood and ear ....Cardiovascular disease is an increasing problem in Australia, however, the cause of atherosclerosis is incompletely understood. A protein, known as apolipoprotein (apo) B, plays a central role in lipoprotein metabolism. Elevated levels of apoB are characteristic of many forms of hypercholestrolaemia. Familial combined hyperlipidaemia and polygenic hypercholesterolaemia are two common inherited disorders of lipoprotein metabolism that are characterised by elevated apoB levels in the blood and early atherosclerosis. In contrast, familial hypobetalipoproteinemia is a rare inherited disorder of lipoprotein metabolism characterised by very low levels of cholesterol and apoB in the blood and resistance to atherosclerosis and cardiovascular disease. The focus of this research project is to explore the regulation of apoB metabolism using individuals from unique families with familial hypobetalipoproteinaemia. First, we will determine and characterise the alterations in the APOB gene causing the low cholesterol levels in families with familial hypobetalipoproteinaemia. Second, we will determine if these apoB alterations affect the production and-or clearance of blood fats, or lipoproteins in affected individuals, when compared to controls, by performing metabolic studies. The proposed human in vivo metabolic studies will lead to a better understanding of the mechanism(s) involved in the assembly, secretion, transport, and clearance of plasma apoB-containing lipoproteins. Furthermore, these studies may reveal new protective mechanisms and potentially aid in the development of strategies to suppress over-production of apoB-containing lipoproteins in reciprocal conditions such as familial combined hyperlipidaemia or polygenic hypercholesterolaemia.Read moreRead less
Leptin And The Regulation Of Substrate Partitioning
Funder
National Health and Medical Research Council
Funding Amount
$349,876.00
Summary
The prevalence of obesity is increasing with currently 18% of adult Australians being classified as obese. Obesity, particularly abdominal obesity, is associated with high blood lipid levels and blood pressure, and type 2 diabetes. In Australia, the cost of obesity is estimated to be $830 million per year. The ultimate aim of any obesity treatment programme is to reduce body fatness by burning off fat and to prevent further fat storage and so studies which focus on developing strategies to achie ....The prevalence of obesity is increasing with currently 18% of adult Australians being classified as obese. Obesity, particularly abdominal obesity, is associated with high blood lipid levels and blood pressure, and type 2 diabetes. In Australia, the cost of obesity is estimated to be $830 million per year. The ultimate aim of any obesity treatment programme is to reduce body fatness by burning off fat and to prevent further fat storage and so studies which focus on developing strategies to achieve these goals are very important. We have found that subjects who fail to keep weight off after being on a weight-reducing diet are bad fat burners. These people also have low levels of leptin, a hormone made by fat cells which helps to regulate food intake. The first aim of this study is to show that leptin increases the burning of fat by regulating the production and activity of factors which decide whether fat is used for energy or is stored in the body. The second aim is to find ways in which leptin levels can be changed so that fat burning is increased. Some of the ways in which we will change leptin levels are by changing the fat content of the diet, or by drugs, or by giving leptin itself. These studies will be performed in animal models of obesity and will help us to develop strategies for the treatment and prevention of obesity in humans.Read moreRead less
Identifying A Novel Role For Pigment Epithelium-derived Factor In Obesity-related Metabolic Dysfunction
Funder
National Health and Medical Research Council
Funding Amount
$361,637.00
Summary
Obesity is an important factor contributing to insulin resistance and type 2 diabetes; however, the factors linking these disorders are not well defined. A protein called PEDF is elevated in obesity and type 2 diabetes. This project will examine how PEDF causes insulin resistance and whether blocking PEDF's actions prevents insulin resistance. Successful completion of this project may lead to therapeutics that reduce the risk of developing type 2 diabetes.
The Role Of Endothelial Lipase In High Density Lipoprotein Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$130,550.00
Summary
Atherosclerosis is a major cause of death and disability in Australia. A high level of blood cholesterol increases the risk of developing atherosclerosis. This increase in risk is caused by the cholesterol that is carried in low density lipoproteins (LDL). However, not all cholesterol is bad. A proportion of the cholesterol in blood is carried in high density lipoproteins (HDL), which are powerful protectors against atherosclerosis. As not all HDL protect equally well against atherosclerosis, it ....Atherosclerosis is a major cause of death and disability in Australia. A high level of blood cholesterol increases the risk of developing atherosclerosis. This increase in risk is caused by the cholesterol that is carried in low density lipoproteins (LDL). However, not all cholesterol is bad. A proportion of the cholesterol in blood is carried in high density lipoproteins (HDL), which are powerful protectors against atherosclerosis. As not all HDL protect equally well against atherosclerosis, it is important to know how blood levels of HDL are regulated. In 1999 a new enzyme called endothelial lipase was discovered. Endothelial lipase dramatically decreases HDL levels in mice. The reason why this happens is not known. The main aims of this project are to work out how endothelial lipase decreases HDL levels and whether it decreases the levels of all HDL equally or whether it preferentially decreases the levels of certain types of HDL. The outcome of this project will establish how endothelial lipase affects the ability of HDL to protect against atherosclerosis in humans.Read moreRead less
Niemann Pick Disease Type C And Intracellular Sterol Trafficking
Funder
National Health and Medical Research Council
Funding Amount
$317,741.00
Summary
Abnormal distribution of cellular cholesterol causes Nieman Pick Disease type C (NP-C), and is also strongly associated with common neurodegenerative diseases such as Alzheimer's disease. We aim to understand the molecular mechanisms by which cholesterol is sorted and transported in the cell. Our results may help develop effective therapeutic strategies against NP-C, Alzheimers' disease and other cholesterol related disorders.