Protease-activated Receptors As Potential Drug Targets In Allergic Airways Disease
Funder
National Health and Medical Research Council
Funding Amount
$469,500.00
Summary
Asthma is a lung disease that kills about 700 Australians each year and causes widespread morbidity in our community. For people with allergic asthma inhalation of allergens such as those contained in house dust triggers an immune response that causes swelling of the airway wall, overproduction of mucus and bronchial smooth muscle contraction. These effects lead to the narrowing of the airways that makes breathing more difficult in people with asthma. Our research groups have been investigating ....Asthma is a lung disease that kills about 700 Australians each year and causes widespread morbidity in our community. For people with allergic asthma inhalation of allergens such as those contained in house dust triggers an immune response that causes swelling of the airway wall, overproduction of mucus and bronchial smooth muscle contraction. These effects lead to the narrowing of the airways that makes breathing more difficult in people with asthma. Our research groups have been investigating a novel group of proteins, called protease-activated receptors (PARs), and in an exciting development have found that substances that stimulate PARs inhibit allergic airways inflammation in mice, which is a well-established animal model of allergic asthma. This raises the possibility that PAR stimulants may in the future be developed as anti-asthma drugs. However, there are many large gaps in our understanding of airway PARs that need to be filled before their use as anti-asthma drugs can be contemplated. Thus, the current study will address many important questions: Do PAR stimulants always improve allergic inflammation, or are there some doses or times of dosing that worsen allergic inflammation? Stimulants of one PAR, called PAR2, improve allergic inflammation, but what about stimulants of the three other PARs (PAR1, PAR3 and PAR4) that exist in the airways? How do PARs improve allergic inflammation, and which substances and cells are involved? Are PAR stimulants also effective in more complex animal models of allergic inflammation, such as those involving proteolytic allergens (e.g. Der p1 from the house dust mite), respiratory tract viruses, and extended periods of allergen exposure (chronic models) that better reflect the human disease allergic asthma? The answers to these and a range of other questions will significantly improve our understanding of the potential utility of PAR stimulants in the treatment of allergic airways disease.Read moreRead less
The Role Of Protease-activated Receptor-2 In Regulation Of Bone Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$216,100.00
Summary
Many diseases of bones, such as osteoporosis and delayed fracture repair, result from the abnormal function of bone cells. Factors regulating bone cell function are, therefore, important in maintaining a healthy skeleton, as well as in the skeleton's response to disease. We have recently demonstrated the presence of a receptor called PAR-2 on bone-forming cells. We have also shown that activation of PAR-2 inhibits the development of bone-resorbing cells (osteoclasts) in response to hormones. We ....Many diseases of bones, such as osteoporosis and delayed fracture repair, result from the abnormal function of bone cells. Factors regulating bone cell function are, therefore, important in maintaining a healthy skeleton, as well as in the skeleton's response to disease. We have recently demonstrated the presence of a receptor called PAR-2 on bone-forming cells. We have also shown that activation of PAR-2 inhibits the development of bone-resorbing cells (osteoclasts) in response to hormones. We plan to investigate the mechanism of this effect, as well as to identify how PAR-2 activation modulates other responses of bone cells to hormones. Molecules that activate PAR-2 are present in bone in certain disease situations, but it is not known what activates PAR-2 in bone under normal conditions. We will identify physiological activators of PAR-2 within bone.Read moreRead less
Effect Of Prostaglandin E2 On The Periodontium And Alveolar Bone Formation
Funder
National Health and Medical Research Council
Funding Amount
$211,527.00
Summary
Dental disease affecting the supporting structures of teeth (the periodontium), is prevalent in our society. Periodontal disease results in destruction of bone around teeth, loosening of teeth, compromised chewing function, and tooth loss. Over the last twenty years reports into the effects of prostaglandin E2 (PGE2) on the skeleton have been divided and controversial. While historically PGE2 has been reported to promote bone resorption, more recently it has been demonstrated that when PGE is pl ....Dental disease affecting the supporting structures of teeth (the periodontium), is prevalent in our society. Periodontal disease results in destruction of bone around teeth, loosening of teeth, compromised chewing function, and tooth loss. Over the last twenty years reports into the effects of prostaglandin E2 (PGE2) on the skeleton have been divided and controversial. While historically PGE2 has been reported to promote bone resorption, more recently it has been demonstrated that when PGE is placed in contact with mandibular bone, adjacent to erupted teeth, new bone and cementum formation occurs. The ability of PGE2 to induce new bone formation indicates a potential use for PGE2 in the management of bone loss associated with periodontal diseases, and the formation of new bone around dental implants, and around teeth following orthodontic movement. Growth factors are active in healing and have valuable applications in augmenting wound repair. Osseous and dental tissues are rich in growth factors, and these factors are involved with the regulation of bone metabolism as well as tissue repair, thus the action of PGE2 on the periodontium is most likely regulated via these factors. Since regeneration of the periodontium is a fundamental goal of dentistry, any treatment which leads to predictable formation of new connective tissues and their long term stability would be a major clinical advance.Read moreRead less
Cellular Mechanisms Of Pacemaking In The Upper Urinary Tract: Effects Of Sensory Neuropeptides And Prostaglandins
Funder
National Health and Medical Research Council
Funding Amount
$80,680.00
Summary
The mammalian upper urinary tract (UUT) serves to propel urine from the renal pelvis within the kidney through the ureter to the bladder, where it is stored until micturition. This propulsion of urine from the renal pelvis to the bladder occurs by the means of spontaneous peristaltic contractions in the smooth muscle wall of the UUT, intimately dependent on the localized release of prostaglandins. Approximately 10% of the population suffer from renal calculi (kidney stones) at some stage of thei ....The mammalian upper urinary tract (UUT) serves to propel urine from the renal pelvis within the kidney through the ureter to the bladder, where it is stored until micturition. This propulsion of urine from the renal pelvis to the bladder occurs by the means of spontaneous peristaltic contractions in the smooth muscle wall of the UUT, intimately dependent on the localized release of prostaglandins. Approximately 10% of the population suffer from renal calculi (kidney stones) at some stage of their lifetime, with men being 2-4 times more likely than women to have calculi. Pain management of renal colic usually involves the prescribing of strong analgesics, and antispasmodic and nonsteroidal anti-inflammatory agents. Most stones are expelled spontaneously if they are small. Larger stones require interventions such as fragmentation (extracorpereal lithotripsy), which is an out patient procedure, or physical removal, using ureterscopes or endoscopes or open surgery under general anesthesia; procedures usually requiring hospital stays of 2-7 days. This project will provide valuable information on the mechanisms by which sensory nerves and endogenous prostaglandins control motility in the mammalian UUT. In particular, these studies will contribute to the search of specific anti-inflammatory agents which will affect particular aspects of UUT motility. A clearer understanding of the cellular origin of UUT rhythmicity will lead to more informed non-surgical interventions to encourage the passing of painful calculi. Such information will also aid in the treatments of other forms of renal colic, during ureteric obstruction, and urinary tract infection. Ureteric stasis is an important condition to avoid, if left untreated permanent kidney damage usually occurs within 6 weeks.Read moreRead less