Mechanosensitive Afferent Nerves And Gastrointestinal Motility
Funder
National Health and Medical Research Council
Funding Amount
$384,693.00
Summary
This project aims to identify the different types of sensory nerves from the gut which cause sensations such as fullness, nausea or pain. These sensory nerves also activate important reflexes that coordinate different regions of the gut to ensure that food is properly digested and propelled. Many studies have examined these sensory nerves and how they can be activated by stretching the gut wall, but very basic questions remain to be answered. We do not know how many different types of sensory ne ....This project aims to identify the different types of sensory nerves from the gut which cause sensations such as fullness, nausea or pain. These sensory nerves also activate important reflexes that coordinate different regions of the gut to ensure that food is properly digested and propelled. Many studies have examined these sensory nerves and how they can be activated by stretching the gut wall, but very basic questions remain to be answered. We do not know how many different types of sensory nerves there are and whether they all respond to stretch in the same way. We cannot identify their specialised endings in the wall of the gut. While these sensory nerves definitely respond to stretch, they are also known to respond to contractions of the gut wall. Despite this, we do not understand how the normal movements of the gut wall activate them, nor why some movements can lead to pain. Most of the experiments will be carried out on small pieces of tissue taken from humanely killed guinea pigs and studied, under highly controlled conditions, in organ baths. The remainder of the study will be on specimens of human gut tissue obtained at surgery. This project will use new techniques to record sensory nerves during both stretch and contraction of the gut wall to understand what activates them. In addition, their endings will be labelled with dye to reveal their different shapes. Using computerised imaging techniques we will identify whether they respond to particular patterns of movement in the gut wall. Lastly we will record from these sensory neurones in live specimens of human colon to see whether the same types of sensory nerves are present in humans as in the small animals. This study will provide the first comprehensive account of sensory nerves to the gut wall that respond to distension, including those that activate pain pathways. This is a pre-requisite for designing new drugs that will target these nerve cells with minimal side effects.Read moreRead less
The Role Of A Low Emulsifier Diet To Treat Crohn's Disease
Funder
National Health and Medical Research Council
Funding Amount
$447,603.00
Summary
Currently, there are no specific diets known to treat Crohn’s disease (CD). Initial lab- and animal-based studies have indicated emulsifiers added to food drive inflammation in CD, but no human trials completed. This study will design and feed high and low emulsifier diets to healthy and CD subjects and measure markers of inflammation. This will establish the role of a low emulsifier diet to treat CD.
Genetic Validation Of Stat3 As A Tractable Pharmacological Target In Gastrointestinal Disease
Funder
National Health and Medical Research Council
Funding Amount
$586,964.00
Summary
Cancers of the stomach and the colon are a major health burden. One of the central signaling molecules that drives these cancers is called Stat3. Here we propose to use a novel strain of mice that allows us to experimentally dial down the amount of Stat3 protein and hence to predict how effective a future anti-Stat3 cancer drug will be.
Bacterial pathogens are a major cause of illness and death, producing diseases ranging from acute infections to cancer. However, not all infected individuals will succumb to these pathologies. What factors dictate which individuals develop these diseases is an important complex question. The core focus of my research is the identification and characterisation of novel host factors that are involved in resistance or susceptibility to bacterial-associated diseases of the gastrointestinal tract.
Regulation Of Cellular Responses To Neuropeptides.
Funder
National Health and Medical Research Council
Funding Amount
$83,510.00
Summary
Neuropeptides are chemicals released from nerves that are responsible for communication between the nerves, glands, muscles or other nerves. Neuropeptides exert their diverse biological effects by interacting with small structures on the cells they wish to communicate with. These structures bind the neuropeptide and are termed neuropeptide receptors. The responses of tissues to neuropeptides, for example, contraction of muscle, decrease with continued exposure to the neuropeptide. This reduction ....Neuropeptides are chemicals released from nerves that are responsible for communication between the nerves, glands, muscles or other nerves. Neuropeptides exert their diverse biological effects by interacting with small structures on the cells they wish to communicate with. These structures bind the neuropeptide and are termed neuropeptide receptors. The responses of tissues to neuropeptides, for example, contraction of muscle, decrease with continued exposure to the neuropeptide. This reduction in response is termed desensitization is thought to turn off the response to cells following stimulation by neuropeptides. In this study, I will investigate the mechanisms behind the desensitization of VPAC receptors which are a found throughout the body and have many important roles for example, gastrointestinal, pancreatic and reproductive function and control of muscle. VPAC receptors are also highly expressed in certain many cancers such as breast, prostate and colon carcinoma. The wide variety of functions that these receptors perform and the wide distribution in the body suggest that these are very important receptors. To date research into the responses and desensitisation of these receptors has been lacking, and the work that has been done has become confusing as more receptors and neuropeptides which bind them are discovered. The current project aims to carefully study these receptors and to determine their role in health and disease. The understanding the interaction of receptor and neuropeptide can perhaps lead to development of new therapeutic agents.Read moreRead less
Pancreatic Cancer is the fourth leading cause of cancer death in men and women in Western societies. Nothing, apart from surgery in a small proportion of individuals gives any hope. The identification of novel treatment strategies in the modern era necessitates a rational scientific approach, where an understanding of the molecular mechanisms involved in the evolution of cancer underpins the development of such strategies in an efficient manner. Retinoids are derivatives of Vitamin A, and have b ....Pancreatic Cancer is the fourth leading cause of cancer death in men and women in Western societies. Nothing, apart from surgery in a small proportion of individuals gives any hope. The identification of novel treatment strategies in the modern era necessitates a rational scientific approach, where an understanding of the molecular mechanisms involved in the evolution of cancer underpins the development of such strategies in an efficient manner. Retinoids are derivatives of Vitamin A, and have been used extremely successfully in the treatment of some leukaemias. Unfortunately, retinoids have not worked as well in other cancers. We have identified an important role for abnormal retinoid function in the evolution of pancreatic cancer, which may be responsible for the lack of effective response to retinoid treatment. This project focuses on identifying if these abnormalities in retinoid function can be reversed with adding specific pharmaceuticals so that retinoid based therapies will be effective in pancreatic cancer.Read moreRead less
Gut motility requires enteric neurons, which are located in the gut wall. During development, enteric neurons arise from precursors in the brain that migrate into the intestine. Failure of enteric neuron precursors to migrate and differentiate normally results in pediatric motility disorders. The aim of this research is to identify the mechanisms controlling the development of enteric neurons so that therapies can be developed for pediatric motility disorders.
Inflammation Drives TFF2 Epigenetic Silencing In Gastric Cancer
Funder
National Health and Medical Research Council
Funding Amount
$618,909.00
Summary
Over one million deaths from stomach cancer will occur annually in the next decade. This often fatal disease can be caused by infection from childhood by the bacterium H. pylori. We will study a new link between the inflammation caused by H. pylori and a type of mutation known as epigenetic silencing that switches off a gene which normally prevents stomach cancer. Understanding this process will help us to discover approaches for early detection of stomach cancer and lead to the development of n ....Over one million deaths from stomach cancer will occur annually in the next decade. This often fatal disease can be caused by infection from childhood by the bacterium H. pylori. We will study a new link between the inflammation caused by H. pylori and a type of mutation known as epigenetic silencing that switches off a gene which normally prevents stomach cancer. Understanding this process will help us to discover approaches for early detection of stomach cancer and lead to the development of new drugs that prevent disease.Read moreRead less
I am a physiologist with expertise in endocrinology determining the roles of particular regulatory peptides in the normal functions of the gastrointestinal tract and in the development of gastrointestinal, renal and prostate cancers.
Chronic Gastrointestinal Symptoms And Diabetes Mellitus: Risk Factors And Mechanisms
Funder
National Health and Medical Research Council
Funding Amount
$271,527.00
Summary
Why many people with diabetes mellitus are afflicted by gastrointestinal (GI) symptoms remains uncertain. Irreversible damage to the nerves controlling the gut (autonomic neuropathy) is often considered to be important. An alternative cause of increased GI symptomatology in diabetics is poor glucose control. Some studies have shown that acute shifts in glucose levels induce changes in the gut relevant to the onset of GI symptoms. For example, high glucose levels acutely cause slower stomach empt ....Why many people with diabetes mellitus are afflicted by gastrointestinal (GI) symptoms remains uncertain. Irreversible damage to the nerves controlling the gut (autonomic neuropathy) is often considered to be important. An alternative cause of increased GI symptomatology in diabetics is poor glucose control. Some studies have shown that acute shifts in glucose levels induce changes in the gut relevant to the onset of GI symptoms. For example, high glucose levels acutely cause slower stomach emptying times, leading to feelings of fullness. Though the effects of chronic glucose levels are yet to be properly explored, population data show that poor control in the long-term is related to an increase in symptoms. The aim of this prospective study is to determine the roles played by both autonomic neuropathy and glucose control in the development of GI symptoms among diabetics. All past research has been cross-sectional, and so cannot tell us if one or both of these factors cause GI problems in diabetes. For example, it is possible that autonomic neuropathy causes an increase in GI symptoms such as nausea and fullness, which in turn induces poor glucose control though lack of appetite or inadequate stomach emptying. Upon study inclusion, all study participants will undergo a series of autonomic tests. At 3 month intervals for a period of 30 months, they will be asked to complete a 2-week diary card detailing their GI symptoms and glucose readings, and also supply blood and urine samples for analysis twice each year. Two years from the study outset, participants will again complete the autonomic test series. Psychiatric co-morbidity will be investigated using the Composite Diagnostic Interview (CIDI-Auto) at the autonomic testing time points. The study will be undertaken at the Gastroenterology Research Unit at Nepean Hospital, in collaboration with the Royal Adelaide Hospital, centres with proven track records in diabetes investigation.Read moreRead less