Following a meal glucose circulates in the blood and is taken up into cells via movement of an intracellular glucose transporter from the inside of the cell to fuse with the cell membrane and subsequent transfer of the glucose into the cell. This process is triggered by insulin. One of the commonest diseases resulting from a failure of this cellular process is diabetes. A common form of diabetes which occurs in many adults in Australia results from insulin resistance, whereby the effects of insu ....Following a meal glucose circulates in the blood and is taken up into cells via movement of an intracellular glucose transporter from the inside of the cell to fuse with the cell membrane and subsequent transfer of the glucose into the cell. This process is triggered by insulin. One of the commonest diseases resulting from a failure of this cellular process is diabetes. A common form of diabetes which occurs in many adults in Australia results from insulin resistance, whereby the effects of insulin are diminished and cells become increasingly unable to uptake glucose. Recent studies have demonstrated that a novel enzyme known as SHIP-2 may play a role in regulating insulin action in cells. Deletion of SHIP-2 in mice results in these animals have increased sensitivity to insulin, low blood glucose levels, and a greatly enhanced ability to take up glucose in cells in response to low dose insulin. Our laboratory has been working on the cellular mechanisms regulating SHIP-2 function. We have recently revealed the intracellular location of SHIP-2 and also demonstrated how SHIP-2 is localized in the cell. These studies have shown that SHIP-2, via interactions with other proteins, regulates the actin cytoskeleton immediately beneath the cell membrane and this may be a mechanism for facilitating cellular glucose uptake. This research proposal aims to determine how SHIP-2 facilitates glucose uptake into cells. We will make cell lines and transgenic animals which express high levels of this enzyme and determine the functional consequences on insulin stimulated glucose uptake. Collectively these studies in the long term may facilitate better treatment strategies for diabetic patients.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