Mechanisms Of Oxidised Protein Accumulation In Ageing Cells
Funder
National Health and Medical Research Council
Funding Amount
$429,000.00
Summary
Australia has one of the world's most rapidly ageing populations. It is estimated that in 30 years time over 30% of the population will be over 65; many will suffer from a debilitating, age-related disease. The diseases of ageing represent one of the major health challenges this century. Despite their increasing incidence, our understanding of the underlying causes is limited. A common feature is the accumulation of damaged proteins in cells and tissues. Damaged proteins are usually broken down ....Australia has one of the world's most rapidly ageing populations. It is estimated that in 30 years time over 30% of the population will be over 65; many will suffer from a debilitating, age-related disease. The diseases of ageing represent one of the major health challenges this century. Despite their increasing incidence, our understanding of the underlying causes is limited. A common feature is the accumulation of damaged proteins in cells and tissues. Damaged proteins are usually broken down by the cells and replaced, but in many age-related diseases this process fails. The most common source of protein damage is attack by oxygen-derived free radicals. These are by-products of our body's need for oxygen and can originate from atmospheric pollutants. Oxygen rusts metal, makes fat go rancid and can cause irreparable damage to proteins and other biological molecules. Free radical damage contributes to the development of many age-related diseases such as atherosclerosis and neurodegenerative diseases such as Alzheimer's disease. The accumulation of damaged proteins can cause cell death. Our knowledge of the mechanisms by which cells remove proteins damaged by oxygen and the reasons for their accumulation is limited. In this project we will use a novel technique we have developed to generate oxidised proteins in ageing cells. We will identify cellular mechanisms required for the efficient removal of damaged proteins and those mechanisms which fail in ageing cells. We will focus on a group of proteins which protect damaged proteins from aggregating and accumulating and we will examine how we can prevent the accumulation of oxidised proteins by stimulating the body s defence mechanisms. Since the population of Australia is ageing, diseases of ageing are going to consume an increasing amount of the national health budget. A better knowledge of these cellular mechanisms will allow us to design effective prevention and treatment strategies which are at present lacking.Read moreRead less
Invasive fungal infections are a serious, escalating health issue. They cause severe disease with high death rates and are very costly to the health system. Current drugs often have suboptimal efficacy and cause side effects. New drugs are needed urgently. Many fungi, including the AIDS-related pathogen, Cryptococcus neoformans, secrete phospholipase B (Plbp) to facilitate infection. We will identify and investigate the Plbp secretion pathway as a novel anti-fungal drug target.
Does Early Overnutrition Differentially Alter Hypothalamic Neuropeptides That Regulate Food Intake In The Rat
Funder
National Health and Medical Research Council
Funding Amount
$346,250.00
Summary
In Australia the incidence of obesity, in particular childhood obesity, is increasing dramatically, and the possible long term consequences of this are of great concern. The brain regulates appetite through a number of chemical transmitters such as neuropeptide Y (NPY) which is present in the brains of mammals and causes increased food intake. The effects of overeating from a young age on these brain transmitters has been largely ignored although this may impact on subsequent eating behaviour. I ....In Australia the incidence of obesity, in particular childhood obesity, is increasing dramatically, and the possible long term consequences of this are of great concern. The brain regulates appetite through a number of chemical transmitters such as neuropeptide Y (NPY) which is present in the brains of mammals and causes increased food intake. The effects of overeating from a young age on these brain transmitters has been largely ignored although this may impact on subsequent eating behaviour. In addition to NPY we will study other transmitters in the brain that have profound effects on appetite, some increasing, and others decreasing, food intake. These may form useful therapeutic targets for new drugs for obesity. Key targets we will study include melanocortins, glucagon-like peptide 1, urocortin, melanin concentrating hormone, agouti related peptide, and NPY. We will determine whether overnutrition from birth to weaning leads to changes in these appetite regulating neurotransmitters in the brain, and monitor the hormonal signals that impact on their activity. We will also determine whether early overnutrition exacerbates the subsequent responses to a high fat diet by comparison with rats made obese as adults. We will measure brain concentrations of the neurotransmitters, the amount released from the brain, and determine whether the feeding responses to injections of these agents is altered in obese animals. We have evidence that these transmitters interact in a co-ordinated fashion to affect feeding; this project will examine whether these interactions are maintained in the various types of obesity. Rats are commonly used for this type of study as the processes regulating feeding are very similar to those in humans and these agents cause similar effects in rats and humans. It is hoped that this information will provide new insight into the way brain adapts to overnutrition, and provide potential treatments for obesity and other feeding disorders.Read moreRead less
Assembly And Transport Of Herpes Simplex Virus Within Neurones
Funder
National Health and Medical Research Council
Funding Amount
$475,500.00
Summary
Herpes simplex virus (HSV) enters the human body via the skin before entering the termini of nerve cell processes. It is transported along these processes to the body of the nerve cell. HSV lies dormant within these nerve cell bodies near the spinal cord in most people. Intermittently the virus reactivates and is transported back down the nerve cell processes to the skin where it causes blisters-ulcers or is shed without causing symptoms. The aim of this grant is to determine how HSV is transpor ....Herpes simplex virus (HSV) enters the human body via the skin before entering the termini of nerve cell processes. It is transported along these processes to the body of the nerve cell. HSV lies dormant within these nerve cell bodies near the spinal cord in most people. Intermittently the virus reactivates and is transported back down the nerve cell processes to the skin where it causes blisters-ulcers or is shed without causing symptoms. The aim of this grant is to determine how HSV is transported and assemblied within nerve cells at the molecular level. Recent discoveries have shown how virus transport in nerve cells is dependent on interactions between specific viral proteins and cellular motor proteins. Such information on viral transport and assembly mechanisms will allow development of inhibitors of these processes which may be candidates for use as antivirals for control of recurrent herpes simplex. In addition, this information will allow the virus to be exploited for use in gene therapy to introduce DNA into human nerve cells to correct genetic abnormalities.Read moreRead less
Targeting PI3K-regulated MicroRNAs To Treat Heart Failure
Funder
National Health and Medical Research Council
Funding Amount
$532,593.00
Summary
Current therapeutics largely delay heart failure progression rather than regressing it. New therapeutic strategies with the capability of improving function of the failing heart are thus greatly needed. The primary goal of this study is to determine whether novel regulatory genes can enhance cardiac function in a setting of heart failure. Ultimately, technologies that target these genes may lead to innovative pharmacotherapies in the clinical management of heart failure.
The Functional Roles Of ADAMs In The Regulation Of Embryo Implantation.
Funder
National Health and Medical Research Council
Funding Amount
$211,527.00
Summary
The initiation of pregnancy in humans and rodents hinges upon the ability of the embryo to attach to the wall of the uterus and invade into the uterine tissue. This process of embryo implantation is tightly regulated and depends on the secretion of enzymes and regulators of these enzymes. A newly identified family of enzymes which might be important in this process is the ADAMs family. These enzymes have the potential to facilitate both cell attachment and cell invasion and also to activate othe ....The initiation of pregnancy in humans and rodents hinges upon the ability of the embryo to attach to the wall of the uterus and invade into the uterine tissue. This process of embryo implantation is tightly regulated and depends on the secretion of enzymes and regulators of these enzymes. A newly identified family of enzymes which might be important in this process is the ADAMs family. These enzymes have the potential to facilitate both cell attachment and cell invasion and also to activate other enzymes and growth factors. Recent studies in our laboratory have shown the ADAMs to be expressed both at the most invasive time of implantation and when invasion is being down-regulated. This project will examine the role of the ADAMs in embryo implantation facilitating attachment and invasion into the uterus by acting enzymatically on the uterine tissue and by activating other enzymes. It will also determine the role of ADAMs in down-regulating invasion potentially by activating a growth factor, TNF-alpha. Knowledge of this process and particularly its regulation is important for the treatment of pregnancy associated diseases that arise from improper implantation. These include infertility, placenta accreta, choriocarcinoma, miscarriage and pre-eclampsia. Furthermore, an understanding of the regulation of implantation will contribute to the treatment of other conditions associated with cell invasion such as cancer metastasis.Read moreRead less
Transport And Egress Of Herpes Simplex Virus In Neurones
Funder
National Health and Medical Research Council
Funding Amount
$592,023.00
Summary
Herpes simplex virus (HSV) enters the human body via the skin before entering the termini of nerve cell processes. It is transported along these processes to the body of the nerve cell. HSV lies dormant within these nerve cell bodies near the spinal cord in most people. Intermittently the virus reactivates and is transported back down the nerve cell processes to the skin where it causes blisters-ulcers or is shed without causing symptoms. The aim of this grant is to determine how HSV is transpor ....Herpes simplex virus (HSV) enters the human body via the skin before entering the termini of nerve cell processes. It is transported along these processes to the body of the nerve cell. HSV lies dormant within these nerve cell bodies near the spinal cord in most people. Intermittently the virus reactivates and is transported back down the nerve cell processes to the skin where it causes blisters-ulcers or is shed without causing symptoms. The aim of this grant is to determine how HSV is transported within nerve cells at the molecular level. Recent discoveries have shown how virus transport in nerve cells is dependent on interactions between specific viral proteins and cellular motor proteins and how the virus escapes from nerves to infect skin and cause disease. Such information on viral transport will allow development of inhibitors of this process which may be candidates for use as antivirals for control of recurrent herpes simplex. In addition, this information will allow the virus to be exploited for use in gene therapy to introduce DNA into human nerve cells to correct genetic abnormalities. Finally this data will assist in understanding similar mechanisms for other viruses transported in nerve cells such as those causing shingles and rabies.Read moreRead less
Molecular Regulation Of CRH Gene Expression In The Human Placenta
Funder
National Health and Medical Research Council
Funding Amount
$70,285.00
Summary
Approximately 70% of infant death is a result of premature birth. Preterm delivery occurs in 6-10% of pregnancies, and there has been no reduction in this rate in the last 30 years. This is largely because we remain ignorant of how normal and preterm birth is controlled. Understanding the physiology of human pregnancy is a critical step in the development of ways to detect and prevent preterm birth. Our group has demonstrated a link between production of a hormone (corticotropin releasing hormon ....Approximately 70% of infant death is a result of premature birth. Preterm delivery occurs in 6-10% of pregnancies, and there has been no reduction in this rate in the last 30 years. This is largely because we remain ignorant of how normal and preterm birth is controlled. Understanding the physiology of human pregnancy is a critical step in the development of ways to detect and prevent preterm birth. Our group has demonstrated a link between production of a hormone (corticotropin releasing hormone, CRH) in the placenta and the length of time the baby is carried in the mother. In women who will deliver prematurely the rise in CRH production occurs earlier and more rapidly, while in women who deliver late the rise occurs more slowly. This work has led to the concept of a biological clock that determines the length of time the fetus will be carried by the mother before birth, and in which production of CRH in the placenta plays a central role. We have been studying how the CRH gene is controlled in placental cells. We have discovered some regions in the DNA of the CRH gene which have important roles in controlling how much CRH is made by the placenta. The experiments described in this project will determine the molecular mechanisms that control the production of CRH in the human placenta. This will be done by examining the DNA sequences involved in controlling the CRH gene and by identifying the proteins that actually perform the regulating functions that result in either increased or decreased amounts of CRH being produced by the placenta. This important information will help us better understand how normal and preterm birth is controlled, and from that knowledge new ways to detect and prevent premature birth can be developed.Read moreRead less
This proposal is designed to test the protein leverage hypothesis (PLH) in humans: the idea that the level of food consumption in humans, like other animals, is adjusted to maintain a target protein intake. As the prevalence of overweight and obesity increases, with its attendant health problems, the need to identify which dietary components limit rather than exacerbate energy intake is imperative. According to the PLH, the consumption of a diet low in % protein and high in % fat and carbohydrat ....This proposal is designed to test the protein leverage hypothesis (PLH) in humans: the idea that the level of food consumption in humans, like other animals, is adjusted to maintain a target protein intake. As the prevalence of overweight and obesity increases, with its attendant health problems, the need to identify which dietary components limit rather than exacerbate energy intake is imperative. According to the PLH, the consumption of a diet low in % protein and high in % fat and carbohydrate, typical of many Western countries, inevitably requires the ingestion of additional energy to maintain protein intake constant, thus driving weight gain. Conversely, the consumption of a diet that is relatively high in % protein requires the ingestion of lower levels of energy, creating the potential for weight loss. Preliminary experimental and population-level nutritional survey data support the PLH, as does the finding that protein is more satiating than other macronutrients. If, as predicted, small changes in the proportion of protein in diets described in the current study are found to impact on total energy intake there will be significant implications for weight control strategies. Thus, if the PLH is confirmed, public health dietary recommendations and government policy settings for the food industry will need to change. Large-scale intervention studies aimed at demonstrating the longer term impact on body weight will also be required.Read moreRead less
Mechanisms Of Proteolysis Of Proteins Containing Oxidised Amino Acids
Funder
National Health and Medical Research Council
Funding Amount
$406,320.00
Summary
There is evidence that during ageing, and age-related diseases, proteins which have been chemically modified by oxidation accumulate in the body, and may have deleterious effects. Oxidation of proteins is a process akin to that by which fats go rancid. It has been demonstrated by the applicants to be an important process in formation of cataracts, and in development of the blood vessel disease, atherosclerosis, which is responsible for most heart attacks and stroke. Other important age-related d ....There is evidence that during ageing, and age-related diseases, proteins which have been chemically modified by oxidation accumulate in the body, and may have deleterious effects. Oxidation of proteins is a process akin to that by which fats go rancid. It has been demonstrated by the applicants to be an important process in formation of cataracts, and in development of the blood vessel disease, atherosclerosis, which is responsible for most heart attacks and stroke. Other important age-related diseases, such as Alzheimer s disease and other neurological disorders, are also claimed to be associated with deranged protein oxidation, and accumulation of oxidised products. There is clear evidence that certain defensive mechanisms, such as those acting to remove invading organisms and clear wounds, are also associated with an enhanced production of oxidised proteins. Perhaps the most important component of defense against oxidised proteins is their removal by complete breakdown to constituent components, and excretion. Normally, the machinery for breakdown of proteins is in vast excess over the required rate of degradation. However, clearly in these conditions of accumulation of oxidised proteins, this is no longer the case, or no longer suffices. Mechanisms by which oxidised proteins are degraded are poorly understood, and quite controversial. Therefore, the present studies bring to bear a new approach to studying this issue, which has been developed by the applicants. The aim is to reveal mechanisms involved in the breakdown of proteins containing oxidised amino acids, both in cellular systems, and in vivo. Such an understanding may allow us to envisage how to remove oxidised proteins by therapeutic means and therefore interfere with the development of age-related diseases such as Alzheimer s disease and cataract formation and the diseases of the blood vessels associated with attack and stroke.Read moreRead less