The cells that produce and maintain our cartilage, known as chondrocytes, do so by sensing changes in the mechanical environment, but precisely how chondrocytes detect these changes is not known. We are investigating the role of ion channels that are opened in direct response to mechanical movements within the cartilage.This project plans to identify the specific molecules that are participating in this process and to determine if they are therapeutic targets for treatment of osteoarthritis
Failure-to-progress In Human Labour Results From A Profound Electrical Negativity Of The Uterine Cells: Targeting The Ion Channels Involved
Funder
National Health and Medical Research Council
Funding Amount
$564,541.00
Summary
The incidence of failure to progress in labour has increased in recent years, being linked to the rise in obesity. The result is a significant escalation in the rate of delivery by Caesarean Section (CS) which increases the risk of serious complications during subsequent pregnancies. We have identified dysfunctional systems associated with poor uterine contraction. We now aim to determine the mechanisms underlying these dysfunctional systems to lay the foundations for better therapeutics.
The Role Of TRPM2 Channels In Oxidative Stress-induced Liver Damage
Funder
National Health and Medical Research Council
Funding Amount
$576,265.00
Summary
Oxidative stress plays a central role in liver injury induced by drug toxicity, ischemia-reperfusion, non-alcoholic fatty liver disease and viral hepatitis. A hallmark feature of oxidative-stress mediated hepatocellular death is Ca2+ and Na+ overload which suggest activation of ion channels on the plasma membrane. This project will investigate the role of Transient Receptor Potential Melastatine 2 (TRPM2) non-selective channels in oxidative stress-induced hepatocellular death.
P2X7 Receptor And Inflammation In The Pathophysiology Of Mood Disorders
Funder
National Health and Medical Research Council
Funding Amount
$598,063.00
Summary
Mood disorders are chronic disabling mental illnesses affecting a significant proportion of the population. Inherited variations in a particular gene involved in inflammation will be investigated in individuals with mood disorders. This work aims to understand the relationship between inflammation of parts of the brain and mood disorders leading to the potential development of a new therapeutic target.
Molecular Basis Of Voltage Dependent-activation Of HERG K+ Channels
Funder
National Health and Medical Research Council
Funding Amount
$439,500.00
Summary
The rhythm of the normal heart beat is controlled by electrical signals mediated by the flow of electrically charged atoms called ions. The flow of ions across heart cell membranes is predominantly mediated by proteins called ion channels that open and close in response to changes in the voltage across the cell membrane. One of these channels, called the HERG channel, has some unusual properties. Most notably, HERG channels open very slowly following an electrical stimulus, so slowly that they d ....The rhythm of the normal heart beat is controlled by electrical signals mediated by the flow of electrically charged atoms called ions. The flow of ions across heart cell membranes is predominantly mediated by proteins called ion channels that open and close in response to changes in the voltage across the cell membrane. One of these channels, called the HERG channel, has some unusual properties. Most notably, HERG channels open very slowly following an electrical stimulus, so slowly that they do not fully open until the end of the cardiac contraction cycle. These channels are therefore particularly well placed to help suppress arrhythmias initiated by premature or ectopic beats. We propose to undertake a detailed investigation into the mechanisms by which HERG channels open and close and to determine why activation of these channels is so slow. These results will provide a greater understanding of how HERG channels work and how the normal activity of HERG channels helps to suppress abnormal heart rhythms.Read moreRead less
Role Of Nitric Oxide And Reactive Oxygen Species In Excitation-contraction Coupling In Skeletal Muscle.
Funder
National Health and Medical Research Council
Funding Amount
$163,250.00
Summary
Excitation-contraction (E-C) coupling is a term used to broadly describe the sequence of cellular events that starts with an electrical signal at the surface membrane of a muscle cell and which then ultimately leads to muscle contraction. Although the overall sequence is known, there remain many gaps in our understanding of the mechanisms involved not only related to normal muscle function but to how this function may be impaired by excessive exercise and disease. Many cellular metabolites contr ....Excitation-contraction (E-C) coupling is a term used to broadly describe the sequence of cellular events that starts with an electrical signal at the surface membrane of a muscle cell and which then ultimately leads to muscle contraction. Although the overall sequence is known, there remain many gaps in our understanding of the mechanisms involved not only related to normal muscle function but to how this function may be impaired by excessive exercise and disease. Many cellular metabolites contribute towards the normal control of muscle contraction, while others contribute to its impairment. Reactive oxygen species (ROS), which includes nitric oxide (NO) and related molecules, are metabolic factors often referred to as cellular oxidants. They are thought to have an essential role in controlling normal muscle function. Paradoxically, they are also implicated in the impairment of muscle function associated with fatigue, disease and aging. How these molecules both control normal muscle activity and also contribute to impairment of such function remains unclear. Thus, the central aim of this project is to identify the mechanisms by which the cellular oxidants, NO and other ROS, both control normal E-C coupling in skeletal muscle fibres and how they contribute to muscle fatigue. Clearly, understanding how skeletal muscle normally contracts is essential in order to better understand how muscle function can become impaired with exercise, disease and age. The work from this study will provide insight into both normal muscle physiology and how muscles fatigue and ultimately provide new methodologies and drugs that may combat fatigue, disease and age related changes to muscle function.Read moreRead less
Characteristics Of Splice Variants Of The Skeletal Muscle Ryanodine Receptor: Implications For Myotonic Dystrophy
Funder
National Health and Medical Research Council
Funding Amount
$258,000.00
Summary
The project is to address some of the basic molecular changes that occur in skeletal muscle during development and in myotonic dystrophy. Myotonic dystrophy is a significant health issue since it is the most common adult muscular dystrophy, with an occurrence of ~1 in 7000. The results will provide much needed information about the membrane-associated molecular mechanisms that regulate muscle contraction and may provide a basis for drug design and treatment of myotonic dystrophy. Respiration and ....The project is to address some of the basic molecular changes that occur in skeletal muscle during development and in myotonic dystrophy. Myotonic dystrophy is a significant health issue since it is the most common adult muscular dystrophy, with an occurrence of ~1 in 7000. The results will provide much needed information about the membrane-associated molecular mechanisms that regulate muscle contraction and may provide a basis for drug design and treatment of myotonic dystrophy. Respiration and locomotion depend on the release of calcium ions from stores inside muscle cells. Ryanodine receptor calcium channels regulate calcium release from the stores. The essential nature of ryanodine receptors is underlined by death at or before birth when ryanodine receptor expression is defective. In addition genetic defects in the ryanodine receptor cause cardiac arrhythmias, malignant hyperthermia and central core disease. Ryanodine receptor function is compromised in heart failure and fatigue. The essential role of ryanodine receptors makes them a potential therapeutic target, but they are not used in this way because of our limited knowledge of the protein. Myotonic dystrophy is an autosomal dominant multi-system disorder, in which an expansion of non-coding DNA leads to changes in expression of several different proteins. Although the genetic basis of myotonic dystrophy is now reasonably well understood, the contribution of molecular changes in the affected proteins to the myopathy has not been investigated. Our group has recently discovered that the juvenile form of the ryanodine receptor protein is highly expressed in adults suffering from myotonic dystrophy. By discovering more about the properties of the juvenile isoform, we will understand more about the basic mechanisms of ryanodine receptor function in developing muscle and in myotonic dystrophy and be able to design drugs to specifically modify ryanodine receptor activity.Read moreRead less