Defining The Insulin-signalling Defect In Human Insulin Resistance And Type 2 Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$94,280.00
Summary
Problems with the way insulin removes glucose from the circulation contribute to developing type 2 diabetes. Despite research to date, controversy remains regarding the nature of known defects in insulin action and their relevance to humans. We plan to measure molecules involved in insulin action in muscle of people with insulin resistance, which is linked to diabetes. These studies will define new defects that cause insulin resistance and type 2 diabetes in humans.
Osteoporosis is a major health burden resulting from bone fractures in older men and women due to progressive loss of bone and weakening of the skeleton. Although there are currently therapies to reduce bone loss, no current treatment effectively reconstructs lost bone. In this project, which is designed to identify new genes that may in the future be targeted by drugs to reverse osteoporosis, we have identified specific sets of genes that appear to work together to increase bone formation. This ....Osteoporosis is a major health burden resulting from bone fractures in older men and women due to progressive loss of bone and weakening of the skeleton. Although there are currently therapies to reduce bone loss, no current treatment effectively reconstructs lost bone. In this project, which is designed to identify new genes that may in the future be targeted by drugs to reverse osteoporosis, we have identified specific sets of genes that appear to work together to increase bone formation. This proposal is aimed at characterising these genes and the ways in which they work to determine whether they may be good targets for new osteoporosis treatments. We will examine the patterns of these genes in bone. We will also use cell cultures in which bone forming cells develop and function, to determine when the genes are expressed and how they function. We will test the ability of the candidate genes to cause an increase in the amount of bone forming activity in these cell cultures. An increase in bone formation may be caused by an increase in the number bone-forming cells, an increase in the activity of the cells, a decrease in cell death, or a combination of these changes. Each possibility will be tested. This research is important because of the need for new osteoporosis therapies to repair weakened bones. The knowledge resulting from this proposal has the potential to provide an important contribution to skeletal health and thus aged health worldwide.Read moreRead less
The Effect Of PKC Epsilon On The Insulin Receptor And Whole Body Glucose Homeostasis.
Funder
National Health and Medical Research Council
Funding Amount
$82,261.00
Summary
Increased fat availability is strongly associated with insulin resistance and type 2 diabetes. Data from this lab has shown animals lacking a particular enzyme (Protein Kinase C epsilon) are able to compensate for this insulin resistance and maintain normal blood glucose levels by elevating insulin availability, with a major site of action being the liver. This project therefore aims to examine the action of PKC epsilon on insulin clearance by the liver.
Adiponectin: Key Factors Determining Its Metabolic Actions And Influences On Insulin Sensitivity
Funder
National Health and Medical Research Council
Funding Amount
$604,793.00
Summary
Diabetes and obesity are growing at alarming rates due to poor lifestyle and other factors. Adiponectin is a complex molecule secreted by fat tissue that may help to burn fat in other tissues such as muscle and liver. We investigate what are the main determinants of adiponectin action and how these might counteract defective insulin action caused by excessive fat intake. This promises to provide new therapeutic targets to lessen the metabolic derangement associated with diabetes and obesity
Osteoporosis is a major health burden resulting from bone fractures in older men and women due to progressive loss of bone and weakening of the skeleton. No current treatment effectively reverses this bone loss. Using genetic models in mice, we have identified a pathway, involving the nerve signal molecule NPY, that is capable of inducing large (200 - 300%) increases in bone very rapidly (within a few weeks), in the skeleton of adult mice. This proposal is aimed at characterising this new pathwa ....Osteoporosis is a major health burden resulting from bone fractures in older men and women due to progressive loss of bone and weakening of the skeleton. No current treatment effectively reverses this bone loss. Using genetic models in mice, we have identified a pathway, involving the nerve signal molecule NPY, that is capable of inducing large (200 - 300%) increases in bone very rapidly (within a few weeks), in the skeleton of adult mice. This proposal is aimed at characterising this new pathway to assess its potential to provide new treatments for human osteoporosis. This research is important because of the size, rapidity and inducibility of the effect. Moreover, since it originates in the brain, it represents a quite novel mechanism by which the skeleton is potentially maintained and repaired. The experiments contained in the initial sections of the proposal are designed to assess not only the ability of the NPY-pathway to protect against bone loss but also to examine the possibility of repair to a fragile skeleton. The bone loss models chosen for study represent postmenopausal and age-related osteoporosis, two prevalent and increasingly common conditions in the aging world population. The latter section of the proposal seeks to clarify the mechanism by which the increase in bone formation occurs within the bone. Understanding the working of this pathway will be vital in developing future treatment regimens. This proposal investigates a novel, powerful and rapid pathway for repairing weakened skeletons. The knowledge resulting from this proposal has the potential to provide an important contribution to skeletal health and thus aged health worldwide.Read moreRead less
Inhibition Of Glucose-stimulated Insulin Secretion By Protein Kinase C Epsilon
Funder
National Health and Medical Research Council
Funding Amount
$555,693.00
Summary
Type 2 diabetes is a chronic disease which occurs when the pancreas is unable to produce enough insulin for the body to cope with rising blood glucose levels after a meal, and is strongly linked to obesity. We have discovered that fat oversupply activates an enzyme in the pancreas causing defects in insulin release due to glucose. Inhibiting this enzyme helps overcome diabetes, through poorly defined mechanisms that we aim to clarify here. Our work could lead to new therapies for diabetes.
The Mechanism Of Growth Hormone Receptor Activation
Funder
National Health and Medical Research Council
Funding Amount
$679,500.00
Summary
Growth hormone GH excess or deficit results in considerably shortened lifespan. While cardiovascular disease is a major element in this mortality, GH status has also been linked to kidney disease and diabetic retinopathy. Importantly, GH produced locally in breast cells and prostate cells transform s these cells, creating cancers. We aim to define how GH activates its receptor, to facilitate a GH antagonist which results from understanding how GH activates its cell surface receptor.
Comparison Between AICAR And Exercise-induced Stimulation Of Skeletal Muscle AMP-K On Fat/glucose Metabolism In Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$347,036.00
Summary
Background and Rationale: Exercise is important in the life of the diabetic. In well controlled diabetes, the rates of whole body sugar usage and energy production in skeletal muscle (SkM) in response to acute exercise are similar to non-diabetics. However in diabetics, little information is available as to how SkM processes sugar and produces energy during exercise. Insulin controls SkM sugar and energy processing in sedentary subjects. During exercise, these processes are controlled by non-ins ....Background and Rationale: Exercise is important in the life of the diabetic. In well controlled diabetes, the rates of whole body sugar usage and energy production in skeletal muscle (SkM) in response to acute exercise are similar to non-diabetics. However in diabetics, little information is available as to how SkM processes sugar and produces energy during exercise. Insulin controls SkM sugar and energy processing in sedentary subjects. During exercise, these processes are controlled by non-insulin factors. The chemical catalyst AMP activated protein kinase (AMP-K), which has been investigated only in normal exercising rats, is an important alternative regulator of acute sugar processing and energy supply for exercising SkM. No studies of AMP-K activity are available in diabetes. Our studies will focus on i) how important is the stimulation of SkM AMP-K in diabetes to efficient SkM sugar processing and energy production; ii) if the benefits of exercise can be simulated by pharmacological stimulation of AMP-K in sedentary diabetic subjects. We aim to i) compare the metabolic effects of exercise vs pharmacological stimulation of AMP-K in normal and diabetic subjects; ii) define the molecular mechanisms which trigger the AMP-K metabolic responses; iii) determine if the circulating levels of insulin, blood sugar and-or blood fat influence the AMP-K metabolic responses. Likely Outcomes: pharmacological stimulation of AMP-K will improve SkM sugar metabolism, but less so in diabetes. The associated AMP-K stimulation of SkM fat metabolism may blunt the beneficial SkM sugar responses, particularly in diabetes. This information will be used in future drug developments for diabetics which aim to simulate the beneficial AMP-K metabolic effects of exercise.Read moreRead less