Studies Of Metabolites Of Synthetic Flavonols For The Treatment Of Cardiovascular Disease
Funder
National Health and Medical Research Council
Funding Amount
$207,440.00
Summary
Cardiovascular disease, including heart attack and stroke, is the leading killer of Australians. A promising new drug, NP202, can reduce the amount of tissue damaged from a heart attack; however, its mechanism of action remains obscure. NP202 is metabolized to a range of compounds, one of which is partly responsible for its beneficial effects. In this project we will identify other metabolites of NP202 and characterize their biological activity to gain insight into its mechanism of action.
A group of nerves, called sensory nerves, supply most body organs including the uterus, and are well known to transmit information to the brain. It is now known that these nerves are also capable of releasing the chemicals (neuropeptides) from their endings within these body organs to affect their function. In the uterus these chemicals cause the uterus to contract. We have shown that neuropeptides known as tachykinins are effective in lower concentrations when applied to small specimens of uter ....A group of nerves, called sensory nerves, supply most body organs including the uterus, and are well known to transmit information to the brain. It is now known that these nerves are also capable of releasing the chemicals (neuropeptides) from their endings within these body organs to affect their function. In the uterus these chemicals cause the uterus to contract. We have shown that neuropeptides known as tachykinins are effective in lower concentrations when applied to small specimens of uterine tissue taken from non-pregnant women at hysterectomy than when applied to similar uterine specimens taken from pregnant women at caesarean section. The aim of this project is twofold. Firstly, we want to know why the tachykinins are more potent in uterine tissue from non-pregnant women. Possible explanations that we will examine are that tissues from non-pregnant women contain more sites of action at which the peptides can act, or alternatively, that there is decreased breakdown of these tachykinins in uterine tissue from non-pregnant women. This could occur if a substance known to break down the tachykinins in the uterus shows greater activity during pregancy than when a woman is not pregnant. Secondly, we wish to find out if other chemicals (substances that can produce inflammatory responses, and in particular a group of chemicals known as prostaglandins), that are known to be present in greater amounts in the tissues of women during disease states such as dysmenorrhoea, can cause the release of the neuropeptides that we are studying. If they do cause such a release of tachykinins, this could be an important factor contributing to the disease state. Our hypothesis is that tachykinins and the substances which can break them down may play an important role in regulating uterine contractility in non-pregnant and to a lesser degree in pregnant women.Read moreRead less
The maintenance of optimum health and function of living cells, and consequently that of the whole organism, depends on how cells respond to a multitude of physical and chemical stimuli that continually bombard them. The majority of the chemical stimuli such as hormones and neurotransmitters impart their actions not by directly entering the cell, but instead, by binding to a specific receiver protein at the cell surface called a receptor. In one class of such receptors called G protein coupled r ....The maintenance of optimum health and function of living cells, and consequently that of the whole organism, depends on how cells respond to a multitude of physical and chemical stimuli that continually bombard them. The majority of the chemical stimuli such as hormones and neurotransmitters impart their actions not by directly entering the cell, but instead, by binding to a specific receiver protein at the cell surface called a receptor. In one class of such receptors called G protein coupled receptors, the transmission of the message to the interior of the cell involves yet another protein called G protein. It is extremely important to unravel how each of these components, the stimulating agent, the receptor and G protein, works in order to understand how the cells respond to various chemical signals. To make this process even more complex, it was recently shown that another newly discovered group of proteins called receptor activity modifying proteins (RAMPs) too play a critical role in some systems. Understanding what actually is the role of these new players, and how they team-up with the other components to elicit a specific response to a chemical stimulus, forms the basis of this proposal. Such knowledge is central to the unraveling of the processes involved in the maintenance of health, abnormalities that lead to disease, and in the development of new treatments.Read moreRead less
The Structural Basis Of The Interaction Of Insulin-like Peptide 3, A Key Regulator Of Fertility, With Its Receptor.
Funder
National Health and Medical Research Council
Funding Amount
$555,693.00
Summary
The hormone, insulin-like peptide 3, has recently been shown to act directly on male and female germ cells to cause their maturation. It has considerable promise as a therapeutic agent for the regulation of fertility. Drugs based on the peptide may be used to assist in cases of infertility, and drugs that block its action have great potential as male and female contraceptives. Towards these goals, our project aims to understand how this peptide exerts its unique biological effects.
Selectivity And Mode Of Action Of Rho-conopeptide TIA: A Novel Inhibitor Of Alpha1-adrenoceptors.
Funder
National Health and Medical Research Council
Funding Amount
$399,300.00
Summary
A major obstacle to the development of safer and more effective treatments for cardivascular diseases and benign prostatic hyperplasia is the inability to find small molecules with sufficient specificity to be safe and effective. The applicant team brings together a unique set of complementary research interests and skills in using conotoxins to define, at the molecular level, how rho-conotoxins act at the alpha1-adrenoceptor, a major drug target for cardiovascualr and related diseases. Rho-cono ....A major obstacle to the development of safer and more effective treatments for cardivascular diseases and benign prostatic hyperplasia is the inability to find small molecules with sufficient specificity to be safe and effective. The applicant team brings together a unique set of complementary research interests and skills in using conotoxins to define, at the molecular level, how rho-conotoxins act at the alpha1-adrenoceptor, a major drug target for cardiovascualr and related diseases. Rho-conotoxins are novel peptide inhibitors of the alpha1-adrenoceptor that appear to act at an undescribed allosteric site. This Project will use rho-conotoxins and analogues to characterise structurally and functionally how and where this class of conopepides act. The structure activity relationship for rho-conotoxins will be established to guide the development of subtype specific inhibitors. Pairwise interactins between the alpha1-adrenoceptorand TIA will be used to dock TIA onto a homolgy model of the alpha1-adrenoceptor. The long-term goal of the project is to develop new and safer treatments for cardiovascular and related disorders.Read moreRead less
The Pharmacology And Physiology Of GABA-C Receptors
Funder
National Health and Medical Research Council
Funding Amount
$481,980.00
Summary
GABA is one of the most important chemicals in the brain. GABA and its associated receptors (GABA receptors) work together to keep the balance between neuronal excitation and inhibition which is required for normal brain function. There are three types of GABA receptors called GABA-A, GABA-B and GABA-C receptors. Chemicals acting at these receptors may be therapeutically useful in treating neurological probles such as epilepsy, anxiety, depression and memory-related disorders associated with Alz ....GABA is one of the most important chemicals in the brain. GABA and its associated receptors (GABA receptors) work together to keep the balance between neuronal excitation and inhibition which is required for normal brain function. There are three types of GABA receptors called GABA-A, GABA-B and GABA-C receptors. Chemicals acting at these receptors may be therapeutically useful in treating neurological probles such as epilepsy, anxiety, depression and memory-related disorders associated with Alzheimer's disease and schizophrenia. GABA-A and GABA-C receptors are members of the ligand-gated ion channel super family in which the ion channel forms an intergral and central part of the receptor. In response to GABA, the channel opens and chloride ions flow through the channel. This causes an inhibitory action i.e. the cell reduces its rate of firing. This project aims to study GABA-C receptors by investigating what proteins make up the ion channel, by studying the actions of a range of chemicals that have specific effects at these receptors and by identifying amino acids that are important for normal channel function. New chemicals identified in our studies will provide leads for the design and development of new therapeutic agents acting on the brain.Read moreRead less
Molecular Pharmacology Of Receptor Activity Modifying Protein (RAMP) Action
Funder
National Health and Medical Research Council
Funding Amount
$542,012.00
Summary
The maintenance of optimum health and function of living cells, and consequently that of the whole organism, depends on how cells respond to a multitude of physical and chemical stimuli that continually bombard them. The majority of the chemical stimuli such as hormones and neurotransmitters impart their actions not by directly entering the cell, but instead, by binding to a specific receiver protein at the cell surface called a receptor. In one class of such receptors called G protein-coupled r ....The maintenance of optimum health and function of living cells, and consequently that of the whole organism, depends on how cells respond to a multitude of physical and chemical stimuli that continually bombard them. The majority of the chemical stimuli such as hormones and neurotransmitters impart their actions not by directly entering the cell, but instead, by binding to a specific receiver protein at the cell surface called a receptor. In one class of such receptors called G protein-coupled receptors, the transmission of the message to the interior of the cell involves yet another protein called G protein. These receptors are the most abundant type of cell surface receptors and form the targets for nearly 50% of currently used therapeutic drugs. It is, therefore, extremely important to unravel how each of these components works. To make this process even more complex, it was recently shown that another newly discovered group of proteins called receptor activity modifying proteins (RAMPs) too play a critical role in some systems. We have shown that RAMPs interact with many G protein-coupled receptors and that they have a wider range of actions than has previously been appreciated. Moreover, it has been shown that the RAMP-receptor interface is a viable target for drug development. Understanding the extent to which RAMPs interact with G protein-coupled receptors, how they interact with the receptors and the consequences of this interaction forms the basis of the current proposal. Such knowledge is central to the unraveling of the processes involved in the maintenance of health, abnormalities that lead to disease, and in the development of new treatments.Read moreRead less
Development Of DNA Phosphate Crosslinking Agents As Potential Anticancer Drugs
Funder
National Health and Medical Research Council
Funding Amount
$392,545.00
Summary
The principal difficulty in the treatment of the common solid tumours that cause the majority of cancer deaths is the problem of drug resistance. For example, many patients with cancer of the lung, breast or colon respond well to drug treatment with their tumours initially regressing, only to return later in an aggressive drug-resistant form. In this event, the inevitable outcome is that the tumour grows through drug treatment and the patient eventually succumbs and dies. This is also a familiar ....The principal difficulty in the treatment of the common solid tumours that cause the majority of cancer deaths is the problem of drug resistance. For example, many patients with cancer of the lung, breast or colon respond well to drug treatment with their tumours initially regressing, only to return later in an aggressive drug-resistant form. In this event, the inevitable outcome is that the tumour grows through drug treatment and the patient eventually succumbs and dies. This is also a familiar scenario in the treatment of adults with leukaemias and non-Hodgkins lymphomas. The underlying cause of drug resistance is the genetic instability of cancer cells which results in tumours that are heterogeneous, making it almost inevitable that a cancer cell will arise that is resistant to treatment. There are many mechanisms of resistance, some of which are peculiar to particular drug types, some are permeability barriers and some involve genetic deregulation of the biochemistry of cell death. Alkylating agents are one of the most important classes of anticancer drug. They bind irreversibly to the bases in DNA and weld the two strands of the double helix together. This cross-link is a powerful block to DNA replication and leads to the death of cancer cells by the process of programmed cell death. Cancer cells generally become resistant to alkylating agents by invoking repair mechanisms that remove the drug from the DNA bases, a response which breaks the cross-link and returns the DNA to its normal state. In this project, we are developing a new type of alkylating agent that reacts not with the DNA bases but with the phosphate groups of the DNA backbone. By this means the strands of DNA can again be cross-linked but now the linkage is between parts of the DNA that cancer cells cannot separate. In this way, we hope to be able to devise new drugs that are resistant to the normal mechanisms of DNA repair so that they will be active against drug-resistant tumours.Read moreRead less