Receptor Signalling Through Intracellular Calcium Stores In Chromaffin Cells
Funder
National Health and Medical Research Council
Funding Amount
$461,000.00
Summary
The function of cells in the body is controlled by many hormones and neurotransmitters acting on the cell's surface. Hormones and transmitters mediate their effects by producing chemical signals within the cell that regulate its activities. One key cell signalling chemical is calcium, especially in nerve cells which have developed sophisticated mechanisms for using calcium to control their function. Recently, new levels of complexity have been discovered, both in how cell calcium levels are modi ....The function of cells in the body is controlled by many hormones and neurotransmitters acting on the cell's surface. Hormones and transmitters mediate their effects by producing chemical signals within the cell that regulate its activities. One key cell signalling chemical is calcium, especially in nerve cells which have developed sophisticated mechanisms for using calcium to control their function. Recently, new levels of complexity have been discovered, both in how cell calcium levels are modified by hormones and transmitters and in how these complex calcium signals are used by cells to control their function. This project will investigate how hormones and transmitters can produce different types of calcium signals in nerve cells, and how these signals affect different aspects of the nerve cell's function. In particular, it will establish how two different types of specialised calcium stores within nerve cells are used by different classes of hormone and transmitter, and the distinct cellular functions these two calcium stores can regulate. The results will provide fundamental new information on how nerve cells control their activity and may help identify potential new targets for drugs.Read moreRead less
Nutrient Dependent Signalling In Bone Via Calcium Sensing Receptors
Funder
National Health and Medical Research Council
Funding Amount
$226,650.00
Summary
Osteoporosis is a major health problem that affects as many as 10% of the Australian Community and costs the health budget millions of dollars each year. A number of key nutritional factors including calcium and dietary protein intake are known to be important in the development of osteoporosis. This proposal will test the hypothesis that human bone cells express a protein which senses calcium and amino acids, the calcium-sensing receptor, and thereby respond to nuritional signals arising from t ....Osteoporosis is a major health problem that affects as many as 10% of the Australian Community and costs the health budget millions of dollars each year. A number of key nutritional factors including calcium and dietary protein intake are known to be important in the development of osteoporosis. This proposal will test the hypothesis that human bone cells express a protein which senses calcium and amino acids, the calcium-sensing receptor, and thereby respond to nuritional signals arising from the presence of calcium ions and amino acids in plasma. Furthermore, we propose that by promoting osteoblast proliferation, maturation and survival, the calcium sensing receptor acts as the key molecular mechanism by which dietary calcium and protein promotes bone formation.These studies have potential to explain relationships between bpne resorptive activity, which raises local calcium concentrations, and bone formation activity and the coupling of bone forming and resorbing activity. These studies have the potential to explain the positive effects of calcium and protein intake on bone mass and may also shed light on the regulation of the coupling between osteoblastic and osteoclastic activityRead moreRead less
The Plasmalemmal Calcium Pump And Vascular Smooth Muscle Cell Proliferation.
Funder
National Health and Medical Research Council
Funding Amount
$179,593.00
Summary
Excessive growth of smooth muscle cells can lead to adverse effects in our arteries. The level of calcium inside the muscle cells that line our arteries appears to regulate their growth. In these studies we will assess the changes in the synthesis (expression) of a pump which removes calcium from cells. We will also characterise the effects of modifiers of cell growth on the expression of the calcium pump. The effect of directly inhibiting the production of the calcium pump, on the growth of smo ....Excessive growth of smooth muscle cells can lead to adverse effects in our arteries. The level of calcium inside the muscle cells that line our arteries appears to regulate their growth. In these studies we will assess the changes in the synthesis (expression) of a pump which removes calcium from cells. We will also characterise the effects of modifiers of cell growth on the expression of the calcium pump. The effect of directly inhibiting the production of the calcium pump, on the growth of smooth muscle cells and the regulation of calcium will be determined for the first time.Read moreRead less
Heartbeats are considered to arise through specialised pacemaker cells establishing rhythmically generated (i.e. pacemaker) action potentials, which then trigger propagating action potentials in heart muscle causing contraction and pumping of blood. This research proposal aims to challenge the physical model that is used to describe this pacemaker process and resultant heart conduction. Our reasons for doing this derive from our discovery of an alternative pacemaker-conduction mechanism, which w ....Heartbeats are considered to arise through specialised pacemaker cells establishing rhythmically generated (i.e. pacemaker) action potentials, which then trigger propagating action potentials in heart muscle causing contraction and pumping of blood. This research proposal aims to challenge the physical model that is used to describe this pacemaker process and resultant heart conduction. Our reasons for doing this derive from our discovery of an alternative pacemaker-conduction mechanism, which we have shown to operate in various smooth muscles. This mechanism, termed store-based pacemaking, is entirely different to the currently held cardiac model but could readily achieve the same outcome. We will investigate the hypothesis that this pacemaker mechanism is also fundamental to heart pacemaking and conduction. Positive support for our hypothesis, as indicated by our pilot findings, may severely challenge the present model for cardiac pacemaking. Such an outcome will have major ramifications on present interpretation of cardiac function in health and disease and will be particularly important to interpretation of disorders associated with cardiac arrhythmias and heart conduction.Read moreRead less
Genetic Basis Of Sudden Cardiac Death In The Young
Funder
National Health and Medical Research Council
Funding Amount
$574,500.00
Summary
Sudden cardiac death is a devastating complication of a variety of cardiovascular disorders. In the young, sudden cardiac death can be caused by both structural abnormalities of the heart, e.g. cardiomyopathies, and electrical abnormalities of the heart, such as familial long QT syndrome. In most young sudden cardiac deaths, these cardiovascular disorders are caused by underlying gene abnormalities which place individuals at a higher risk of sudden death. The aim of this project is to understand ....Sudden cardiac death is a devastating complication of a variety of cardiovascular disorders. In the young, sudden cardiac death can be caused by both structural abnormalities of the heart, e.g. cardiomyopathies, and electrical abnormalities of the heart, such as familial long QT syndrome. In most young sudden cardiac deaths, these cardiovascular disorders are caused by underlying gene abnormalities which place individuals at a higher risk of sudden death. The aim of this project is to understanding the genetic basis of sudden cardiac deaths in the young. In particular, the study will identify and characterise the specific genes which cause sudden cardiac death, and what the underlying mechanism is regarding how a single gene defect can lead to such a devastating clinical outcome. Understanding the various cardiovascular diseases that cause sudden death, clinically screening at-risk individuals, coupled with the initiation of appropriate therapeutic and preventative strategies such as implantation of cardioverter defibrillators will most likely reduce the incidence of sudden cardiac death in the young of our community. Elucidation of the underlying genetic defects which cause many of these cardiac disorders will substantially improve diagnostic accuracy, will be invaluable for genetically screening at-risk individuals and by making the diagnosis earlier in life, will create a larger therapeutic window to allow initiation of therapies to prevent complications of disease, including sudden death.Read moreRead less
STIM1 And Orai1 Proteins In Store-operated Calcium Entry In Liver
Funder
National Health and Medical Research Council
Funding Amount
$516,552.00
Summary
The liver plays a central role in controlling vital functions of the body. Changes in calcium level in the liver cells regulate most their functions, including fat and carbohydrate metabolism. There is ample evidence that suggests that diseases such as fatty liver and cholestasis affect the control of calcium in the liver. This research will investigate the mechanisms of calcium homeostasis in the liver and provide information for development of new approaches for treating liver disease.