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.
Protein Tyrosine Phosphatases In The Regulation Of Insulin Receptor Signalling And Glucose Uptake
Funder
National Health and Medical Research Council
Funding Amount
$425,250.00
Summary
The key pathological feature of type II diabetes is the lack of cellular response to normal levels of circulating insulin. Insulin binding to its cell surface transmembrane receptor initiates a cascade of events known as cellular signalling that results in amongst other things in the uptake of glucose. Protein tyrosine phosphatases (PTPs) are key negative regulators of insulin-induced signalling events and their inhibition with broad based chemical inhibitors can mimic several actions of insulin ....The key pathological feature of type II diabetes is the lack of cellular response to normal levels of circulating insulin. Insulin binding to its cell surface transmembrane receptor initiates a cascade of events known as cellular signalling that results in amongst other things in the uptake of glucose. Protein tyrosine phosphatases (PTPs) are key negative regulators of insulin-induced signalling events and their inhibition with broad based chemical inhibitors can mimic several actions of insulin and lower blood glucose levels in both normal and diabetic rats. This proposal will examine the roles of PTPs and in particular TCPTP and PTP1B in insulin receptor-mediated signalling and glucose uptake. Moreover we will explore the role of TCPTP in alternate insulin receptor-independent processes for glucose uptake. Our studies will shed light on processes important for the regulation of glucose uptake. Moreover our studies may lead to the development of drugs capable of inhibiting PTPs such as TCPTP, that may allow for enhanced glucose uptake and have therapeutic use in the treatment of type II diabetes.Read moreRead less
Regulation Of Insulin Signalling And Glucose Homeostasis By Protein Tyrosine Phosphatases
Funder
National Health and Medical Research Council
Funding Amount
$542,462.00
Summary
A common feature of type 2 diabetes is high blood glucose due to peripheral insulin resistance. Protein tyrosine phosphatases (PTPs) that antagonise insulin signalling might be important targets for therapeutic intervention in type 2 diabetes; inhibition of specific PTPs may allow for enhanced IR signalling to alleviate insulin resistance. This proposal will examine the roles of PTPs and in particular TCPTP in insulin signalling and glucose homeostasis.
The Role Of Muscle Fatty Acid Oxidation In Regulating Intramyocellular Lipid Accumulation.
Funder
National Health and Medical Research Council
Funding Amount
$169,695.00
Summary
Obesity and the subsequent accumulation of fat in muscle leads to reduced insulin action and an increased risk of type 2 diabetes. This project will investigate the metabolic processes that influence fat accumulation and oxidation primarily in skeletal muscle, the tissue responsible for most fuel utilization in the body. This information will help design therapeutic strategies to prevent the development of type 2 diabetes.
Genetic Programs Induced By The Nuclear Hormone Receptor PPARdelta In Muscle: Control Of Lipid And Energy Homeostasis
Funder
National Health and Medical Research Council
Funding Amount
$432,750.00
Summary
Lipid homeostasis is regulated by dietary intake, de novo synthesis and catabolism. Lipid disease is associated with hyperinsulinemia, and anomalous levels of the lipid triad, i.e. low HDL-cholesterol, high LDL-cholesterol and elevated triglycerides. Increased incidence of cardiovascular disease has been linked to dyslipidemias associated with diet and lifestyle. Diabetes, atherosclerosis, and obesity are comorbidities with these lipid disorders. HDLs have a defensive role in the prevention of d ....Lipid homeostasis is regulated by dietary intake, de novo synthesis and catabolism. Lipid disease is associated with hyperinsulinemia, and anomalous levels of the lipid triad, i.e. low HDL-cholesterol, high LDL-cholesterol and elevated triglycerides. Increased incidence of cardiovascular disease has been linked to dyslipidemias associated with diet and lifestyle. Diabetes, atherosclerosis, and obesity are comorbidities with these lipid disorders. HDLs have a defensive role in the prevention of dyslipidemia by mediating cholesterol efflux from tissues. In contrast, the LDLs accumulate in the arterial wall leading to atherosclerosis. Physiological maintenance of lipid homeostasis requires a dynamic balance between metabolic signalling cascades, diet, lifestyle etc. PPPARs are nuclear hormone receptors that function as fatty acid activated transcription factors that regulate lipid and cholesterol homeostasis. PPARs are bona fide targets for the development of therapeutic compounds useful in the treatment of lipid disorders. PPAR delta is abundantly expressed in skeletal muscle, a major mass peripheral tissue that accounts for ~40% of total body weight. Muscle is a major site of glucose metabolism and, fatty acid oxidation. Furthermore, it is an important regulator of cholesterol homeostasis and HDL levels. Consequently, it has a significant role in insulin sensitivity, the blood lipid profile and lipid metabolism. Understanding the functional role of PPAR delta in skeletal muscle, a peripheral tissue that accounts for 40% of total body weight is of paramount importance in understanding whole body lipid homeostasis. Understsanding these receptors may provide a pharmaceutical solution for the prevention of hyper-lipidemia--cholesterolemia, and atherogenic disease. Moreover, it may lead to the identification of agents that influence a major mass tissue in terms of lipid absorption, and increased fatty acid oxidation, and consequently normalize the blood lipid profile.Read moreRead less