Modulation Of Asthmatic Airway Inflammation By Activation Of Epithelial Proteinase Activated Receptors
Funder
National Health and Medical Research Council
Funding Amount
$188,912.00
Summary
Children and adults feel the symptoms of asthma because their airways close up too easily. We have discovered a new mechanism that the healthy lung uses to keep airways open. The epithelial cells which line the airway release an enzyme that cuts of a small part of another protein, called a PAR receptor, that sits on the same cell. When this happens the epithelial cell releases relaxing substances from their lower surface. The relaxing substances keep the airways open. This grant application is d ....Children and adults feel the symptoms of asthma because their airways close up too easily. We have discovered a new mechanism that the healthy lung uses to keep airways open. The epithelial cells which line the airway release an enzyme that cuts of a small part of another protein, called a PAR receptor, that sits on the same cell. When this happens the epithelial cell releases relaxing substances from their lower surface. The relaxing substances keep the airways open. This grant application is designed to test whether the relaxing system also stops the airways from developing inflammation. If the relaxing system does this we will be able to use the knowlege we have that lets us activate the PAR receptors artificially to design new types of drugs. These drugs would be better than existing asthma drugs because they would prevent inflammation and relax the airways at the same time. These drugs could also be useful in other lung diseases such as chronic bronchitis.Read moreRead less
Pharmacological Regulation Of Airway Smooth Muscle Phenotype
Funder
National Health and Medical Research Council
Funding Amount
$276,742.00
Summary
In Australia there is a high incidence of asthma which impairs quality of life and can sometimes cause death if sufficiently severe. The main cause of asthma is the shortening of muscle surrounding the airway passages that cause the narrowing of these tube-like passages. When airway passages narrow a feeling of chest tightness is perceived by the asthmatic patient. When the narrowing is severe the amount of oxygen being delivered to the blood can be reduced to dangerous levels. When there is mus ....In Australia there is a high incidence of asthma which impairs quality of life and can sometimes cause death if sufficiently severe. The main cause of asthma is the shortening of muscle surrounding the airway passages that cause the narrowing of these tube-like passages. When airway passages narrow a feeling of chest tightness is perceived by the asthmatic patient. When the narrowing is severe the amount of oxygen being delivered to the blood can be reduced to dangerous levels. When there is muscle growth in the airways even small amounts of shortening of the muscle can cause severe narrowing of the airway passages. This research will investigate how muscle grows in asthmatic airways and look for new ways to use drugs to treat this muscle growth. We hope to improve drug treatment of asthma by limiting the amount of airway narrowing caused by muscle contraction.Read moreRead less
Identification And Characterization Of Novel Bioactive Peptides From Australian Conesnails Targeting Pain Pathways
Funder
National Health and Medical Research Council
Funding Amount
$320,803.00
Summary
In recent years, significant advances have been made in the identification of new targets in the central or peripheral nervous systems which may be used to develop new pain killers. However, molecules specifically targeting these receptors and channels are lacking to date. This project will use novel cell-based approaches to find new molecules from conesnails which specifically target receptors involved in pain. These will be useful to increase our understanding of the mechanisms of pain.
Impact Of Airway Wall Fibrosis On The Efficacy Of Anti-asthma Drugs
Funder
National Health and Medical Research Council
Funding Amount
$432,750.00
Summary
Most episodes of asthma are controlled or prevented by current medications. In a small, but significant proportion of asthmatics (5-10%) symptoms persist despite the use of the best combinations of anti-asthma drugs. One of the reasons that acute episodes of asthma occur is that the airway tubes slowly change in structure. These changes involve an increase in the amount of collagen (part of the cement between cells) making the airway stiffer. In this project, we are exploring the impact of the s ....Most episodes of asthma are controlled or prevented by current medications. In a small, but significant proportion of asthmatics (5-10%) symptoms persist despite the use of the best combinations of anti-asthma drugs. One of the reasons that acute episodes of asthma occur is that the airway tubes slowly change in structure. These changes involve an increase in the amount of collagen (part of the cement between cells) making the airway stiffer. In this project, we are exploring the impact of the stiffening of the airway on the way that different cells within the airway wall respond to drugs used to treat asthma. Our initial findings suggest that when the airway wall becomes stiffer with more collagen, there is a diminished benefit from the anti-asthma drugs. This new study is designed to identify the molecular mechanisms for the poor response to the anti-asthma drugs. With this knowledge it will be easier to design and test new drugs that are more effective in severe asthma.Read moreRead less
Airway Virus Infection, Protease-activated Receptors And Microvascular Permeability
Funder
National Health and Medical Research Council
Funding Amount
$421,527.00
Summary
Asthma is an inflammatory airway disease which kills about 800 Australians each year and otherwise afflicts millions of children and adults in all age groups. Respiratory tract viral infections trigger inflammation and asthma. We believe that this is caused by the loss of naturally protective, bronchodilator and anti-inflammatory substances such as prostaglandin E2 and increased production of asthma promoting substances such as endothelins. Both of these substances are made by the epithelial lin ....Asthma is an inflammatory airway disease which kills about 800 Australians each year and otherwise afflicts millions of children and adults in all age groups. Respiratory tract viral infections trigger inflammation and asthma. We believe that this is caused by the loss of naturally protective, bronchodilator and anti-inflammatory substances such as prostaglandin E2 and increased production of asthma promoting substances such as endothelins. Both of these substances are made by the epithelial lining cells of the bronchi where viruses grow. This project will assess the influence of respiratory tract virus infection on epithelial mechanisms for the production of PGE2 and endothelins. Respiratory viral infections are accompanied by airway inflammation and thus by elevated microvascular permeability and oedema which exacerbates obstruction in asthma. We will measure airway microvascular permeability changes during viral infection and assess the protective effect of stimulating protease-activated receptors which increases PGE2 production. The impact of the PAR system on the integrity of microvascular tissue and on epithelial endothelin production has not been previously investigated. In addition, the influence of respiratory tract viral infection on PAR function in this system is also unknown, but is potentially of great importance to our understanding of the behaviour and regulation of this natural bronchoprotective pathway. This work may lead to the use of novel PAR activators as combined bronchodilator-anti-inflammatory therapies in asthma.Read moreRead less
Targeting Post-translational Modifications In TRPV Pain Channels
Funder
National Health and Medical Research Council
Funding Amount
$480,127.00
Summary
The same nerve receptor that binds the pungent component of chilli peppers (TRPV1) is an important part of our pain pathway. TRPV1 also responds to painful heat and acids. Chronic pain is an important unmet medical need and it uses the TRPV1 pathway. After activation by chilli, a feedback system in nerves inactivates TRPV1 and stops pain signalling. This feedback changes in chronic pain. This project aims to understand and exploit this feedback mechanism to find new approaches to pain therapy.
Cellular Actions Of Cannabinoids Within The Spinal Cord Dorsal Horn In A Neuropathic Pain State
Funder
National Health and Medical Research Council
Funding Amount
$432,750.00
Summary
Morphine and other opioids are among the most important drugs used to treat moderate to severe pain. However, some clinically important chronic pain states are relatively insensitive to opioid treatment, such as neuropathic pain which is caused by injury to the nervous system. Human and animal studies indicate that the active ingredient of the plant cannabis sativa, THC, and a number of synthetic cannabis-like drugs (cannabinoids) also have analgesic, or pain relieving properties. Animal studies ....Morphine and other opioids are among the most important drugs used to treat moderate to severe pain. However, some clinically important chronic pain states are relatively insensitive to opioid treatment, such as neuropathic pain which is caused by injury to the nervous system. Human and animal studies indicate that the active ingredient of the plant cannabis sativa, THC, and a number of synthetic cannabis-like drugs (cannabinoids) also have analgesic, or pain relieving properties. Animal studies have shown that cannabinoids potentiate the analgesic effects of opioids. Of particular interest is the finding that cannabinoids reduce the abnormal pain symptoms associated with animal models of neuropathic pain, such as that caused by nerve injury. Several brain regions play a pivotal role in the analgesic actions of both opioids and cannabinoids. In previous studies I have identified the cellular mechanisms by which opioids and cannabinoids produce their analgesic effects in single cells within the brain. In addition, the spinal cord is the initial relay point of painful stimuli entering the central nervous system and is a major site of opioids and cannabinoid analgesic actions. However, the cellular mechanisms underlying cannabinoid and opioid actions within the spinal cord, particularly in pathways which transmit ascending pain information to the brain, are less well understood. In addition, the cellular actions of cannabinoids and opioids in neuropathic pain states are unknown. The proposed study will determine the cellular mechanisms underlying the analgesic actions of cannabinoids and opioids in single neurons identified as belonging to pain pathways within the spinal cord in normal and nerve injured animals. These techniques have the potential to identify analgesic combinations between cannabinoids, opioids and other agents with enhanced therapeutic activity and reduced side effects.Read moreRead less
Angiotensin AT2 Receptor: A Novel Target For Cardiovascular Modulation
Funder
National Health and Medical Research Council
Funding Amount
$692,040.00
Summary
The hormone, angiotensin II, circulates in the blood and increases blood pressure and thickens the heart and blood vessels, all of which contributes to high blood pressure (hypertension). Angiotensin II causes these excitatory effects by acting at particular target sites called AT1 receptors. Drugs called AT1 receptor antagonists are known to block these excitatory actions of angiotensin II at AT1 receptors. Consequently, these compounds lower blood pressure in humans because they block the ongo ....The hormone, angiotensin II, circulates in the blood and increases blood pressure and thickens the heart and blood vessels, all of which contributes to high blood pressure (hypertension). Angiotensin II causes these excitatory effects by acting at particular target sites called AT1 receptors. Drugs called AT1 receptor antagonists are known to block these excitatory actions of angiotensin II at AT1 receptors. Consequently, these compounds lower blood pressure in humans because they block the ongoing stimulatory action of angiotensin II. However, it is now thought that angiotensin II may also be able to act at another target site (AT2 receptor) to cause opposite effects, i.e. decrease blood pressure and inhibit growth effects. Therefore, this project will examine if direct stimulation of AT2 sites can alter blood flows measured in different body regions in hypertensive rats as part of their mechanism to lower blood pressure. In addition, the effects of continuous stimulation of the AT2 site will be examined in hypertensive rats which will be implanted with a radiotransmitter to measure blood pressure without interference, and afterwards, structural measurements of the heart and blood vessels will be made. Additionally, this project will investigate whether stimulation of the AT2 site also contributes to the blood pressure-lowering effect of drugs already mentioned (AT1 receptor antagonists). The rationale for this is that the hormone angiotensin II is still 'free' to act at the AT2 site, even with AT1 receptors being blocked, and lower blood pressure. These studies will determine if stimulation of AT2 sites contributes to the beneficial effects (i.e. decreased blood pressure and decreased cardiovascular growth) of AT1 receptor antagonists in the treatment of high blood pressure. More importantly, these findings may also identify a new therapeutic target site (AT2 receptor) for drug development in the treatment of cardiovascular disease.Read moreRead less