NOVEL CGMP-BASED THERAPIES PREVENT LEFT VENTRICULAR REMODELLING
Funder
National Health and Medical Research Council
Funding Amount
$533,433.00
Summary
Over 300,000 Australians are affected by heart failure. Current drugs for cardiac remodelling (the decline in heart pumping function and changed structure that precede heart failure) slow but not reverse disease progression. We have identified a new, nitrovasodilator-based therapy superior to those currently available. We propose it represents a more effective treatment for reversing abnormalities in both structure and function in the remodelled heart, preventing or delaying heart failure.
TARGETING ROS-INDUCED DAMAGE RESCUES THE DIABETIC HEART
Funder
National Health and Medical Research Council
Funding Amount
$487,669.00
Summary
Over 1 million Australians have diabetes. Many of these patients die from cardiovascular disease. We have identified free radicals as a major cause of decreased pumping function and impaired recovery from each heartbeat in the diabetic heart. Stronger antioxidant approaches and-or activation of protective protein pathways is a more effective treatment for reversing impaired function in the diabetic heart, preventing or delaying heart failure in patients with diabetes.
Urotensin-II In Human Heart: Investigation Of Mechanisms Involved In Cardiac Function
Funder
National Health and Medical Research Council
Funding Amount
$255,990.00
Summary
The normal function of the body is maintained by naturally occurring compounds. Some for example affect the heart, fine tuning it to make it beat faster or slower, or beat with greater or less force when required in different situations in health and disease. We were the first to show just recently that a small protein which occurs naturally in the body, called urotensin-II can affect the way the heart beats. We showed that extremely tiny amounts increase the force of the heart beat. Our finding ....The normal function of the body is maintained by naturally occurring compounds. Some for example affect the heart, fine tuning it to make it beat faster or slower, or beat with greater or less force when required in different situations in health and disease. We were the first to show just recently that a small protein which occurs naturally in the body, called urotensin-II can affect the way the heart beats. We showed that extremely tiny amounts increase the force of the heart beat. Our findings indicate that urotensin-II is the most potent heart stimulator identified to date. In patients with heart failure, short term stimulation of heart contraction is beneficial, supplying the heart and other organs with vital oxygen and nutrients. However, in the long term excessive stimulation causes worsening of the patients condition. Very little is currently known about the way in which urotensin-II alters heart function. The goal of our study is to understand the mechanism involved in urotensin-II mediated effects on the heart. This will involve identifying the location of urotensin-II and its receptors in the heart, and determining what signalling changes occur after the interaction of urotensin-II with its receptors. Urotensin-II must first be cleaved from a larger drug. We will determine where in the heart this cleavage occurs and whether the process is crucial to the ability of urotensin-II to stimulate contraction of the heart. Since stimulators of heart contraction are detrimental to patients with heart failure in the long term, we will determine whether these patients have more urotensin-II in their blood than patients who do not have heart failure. If the levels of urotensin-II are higher in heart failure patients, it may indicate a need to interfere with the interaction of urotensin-II with its receptors.Read moreRead less
Contractile And Relaxant Effects Of B2- And B1-adrenoceptors In Human Heart: Blockade By A Third Generation B-blocker
Funder
National Health and Medical Research Council
Funding Amount
$136,320.00
Summary
The force and the duration of each heart beat can be modified in disease states affecting the heart. They can also be modified by chemicals which occur naturally in the body. Two of the most important naturally occurring chemicals which affect the function of the heart are (-)-noradrenaline and (-)-adrenaline. These chemicals and others which have been synthesized and optimized can also be used therapeutically. They work by activating proteins which occur on the cell surface, called b-adrenocept ....The force and the duration of each heart beat can be modified in disease states affecting the heart. They can also be modified by chemicals which occur naturally in the body. Two of the most important naturally occurring chemicals which affect the function of the heart are (-)-noradrenaline and (-)-adrenaline. These chemicals and others which have been synthesized and optimized can also be used therapeutically. They work by activating proteins which occur on the cell surface, called b-adrenoceptors. When activated, b-adrenoceptors cause an increase in the force of each heart beat and a reduction in the duration of each heart beat. This may be an advantage in conditions where the heart beat is too long. In this study we propose to map the biochemical pathways through which b-adrenoceptors affect each heart beat. The therapeutic management of heart failure has been revolutionized by the use of compounds which block b-adrenoceptors. One such drug, carvedilol is currently used in this country. The way in which it works may not be fully understood. In preliminary experiments we have identified a novel mechanism for carvedilol directly in human heart in which it may work and contribute to it's beneficial effects in the management of heart failure. Our studies will focus on this finding.Read moreRead less
Novel Actions Of Beta-adrenoceptor Antagonists: Implications For The Treatment Of Cardiac Failure
Funder
National Health and Medical Research Council
Funding Amount
$142,630.00
Summary
Almost 2-3 of drugs on the market act on G protein-coupled receptors, and many are antagonists that block receptors. Antagonists were seen as inert compounds that prevent access of natural neurotransmitters or hormones, but recent studies indicate distinct actions. We believe that atypical effects of beta-adrenergic antagonists may explain their usefulness in treating cardiac failure. We seek to understand the process and develop assays to aid the development of new drugs for cardiac failure.
Mechanisms Of Protease-activated Receptor-2-mediated Bronchoprotection
Funder
National Health and Medical Research Council
Funding Amount
$354,758.00
Summary
The incidence of asthma continues to increase globally, yet there have been few real therapeutic advances. Our research, however, has recently uncovered a novel mechanism that protects the airways from inflammatory diseases like asthma. We have found that the layer of cells that line the airways - the epithelium - acts as a detector of early inflammatory events and releases anti-inflammatory substances. The lungs achieve this level of protection via 'sensor' molecules called receptors which are ....The incidence of asthma continues to increase globally, yet there have been few real therapeutic advances. Our research, however, has recently uncovered a novel mechanism that protects the airways from inflammatory diseases like asthma. We have found that the layer of cells that line the airways - the epithelium - acts as a detector of early inflammatory events and releases anti-inflammatory substances. The lungs achieve this level of protection via 'sensor' molecules called receptors which are located in the epithelium. In the case of our discovery, these receptors are called protease-activated receptors (PARs) to highlight the unique manner in which they are turned on or activated by enzymes called proteases. We have discovered that the epithelium of the lungs stores these enzymes and probably releases them during the inital stages of infection. Once released, these enzymes are detected by PARs on epithelial cells which then release substances that inhibit multiple inflammatory pathways. This mechanism protects the airways from effects that make breathing difficult, as in asthma. We have confirmed that this system provides protection in the airways of intact animals. The purpose of this projects outlined in this application is to examine the effects of activating one PAR, PAR2, on several processes in the lung, in order to characterise the individual events and processes that underlie the protective response. These studies will enable us to determine whether synthetic compounds that activate PAR2 are potential novel compounds for the treatment of diseases like asthma.Read moreRead less
MECHANISMS OF CEREBROVASCULAR REGULATION IN HEALTH AND DISEASE
Funder
National Health and Medical Research Council
Funding Amount
$216,430.00
Summary
Failure of the cerebral circulation to meet the brain's immediate high nutritive requirements results in stroke in just a few minutes. Stroke continues to be a major cause of death and disability, and this major medical challenge requires urgent and significant research at the basic level to better understand mechanisms of normal, and then abnormal, regulation of cerebral artery function. The project will examine the importance of a novel mechanism in regulating brain blood flow by affecting the ....Failure of the cerebral circulation to meet the brain's immediate high nutritive requirements results in stroke in just a few minutes. Stroke continues to be a major cause of death and disability, and this major medical challenge requires urgent and significant research at the basic level to better understand mechanisms of normal, and then abnormal, regulation of cerebral artery function. The project will examine the importance of a novel mechanism in regulating brain blood flow by affecting the degree of opening of the cerebral arteries. This mechanism involves activation of an enzyme, Rho-kinase, which is present in the wall of blood vessels. The applicants believe that this process plays an important role in the normal, healthy regulation of blood supply to the brain. Moreover, there are strong reasons for us to speculate that the function of this enzyme is abnormally high in two disease states that are associated with an increased risk of stroke - high blood pressure and subarachnoid haemorrhage. We will employ a variety of techniques to assess the importance of Rho-kinase in cerebral artery function in the living body, and also in isolated segments of artery. The results are expected to provide major new insight into mechanisms that regulate brain blood flow, and the knowledge gained here may lead to better therapies to prevent or treat stroke.Read moreRead less
Does NADPH Oxidase Link Gender, Hormone Replacement Therapy And Outcome After Stroke?
Funder
National Health and Medical Research Council
Funding Amount
$481,439.00
Summary
This project will assess whether the reduction of a novel mechanism to open brain arteries (i.e. via activation of 'Nox' proteins and generation of oxygen radicals) is a possible explanation of why hormone replacement therapy (HRT) increases the risk of stroke in postmenopausal women. We will compare brain artery function of normal mice with those deficient in certain Nox genes in models of menopause, HRT and stroke. This knowledge should lead to safer stroke therapies in women and men.
Molecular Interactions Of Novel Conotoxin Inhibitors Of The Noradrenaline Transporter
Funder
National Health and Medical Research Council
Funding Amount
$392,036.00
Summary
A novel class of conotoxins (chi-conotoxins) has been discovered in the venom of an Australian cone snails, Conus marmoreus. Chi-conotoxins are the first peptide inhibitors of the noradrenaline transporter. From binding studies, it appears they act at a new site, remote from the site of action of antidepressants. This project is aimed at understanding how and where this novel class of peptide binds to the transporter. The results of this study are designed to maximise the potential of these pate ....A novel class of conotoxins (chi-conotoxins) has been discovered in the venom of an Australian cone snails, Conus marmoreus. Chi-conotoxins are the first peptide inhibitors of the noradrenaline transporter. From binding studies, it appears they act at a new site, remote from the site of action of antidepressants. This project is aimed at understanding how and where this novel class of peptide binds to the transporter. The results of this study are designed to maximise the potential of these patented peptides to be used as leads to the development of a new class of therapeutic for controlling the adverse effects of inadequate noradrenaline balance.Read moreRead less