The Effects Of Intestinal Inflammation On The Currents And Channels Of Identified Enteric Neurons
Funder
National Health and Medical Research Council
Funding Amount
$476,264.00
Summary
Intestinal inflammation, in gastroenteritis, Crohn's disease, ileitis or colitis, has effects on the motility (movement) of the gastrointestinal and on secretion within it. The symptoms that are recognised are poor digestion, crampy pains and diarrhoea. The symptoms often continue after the inflammation has subsided. The major disease entity that can develop after inflammation is the irritable bowel syndrome (IBS). IBS is associated with persistent disorders of bowel motility. The symptoms are t ....Intestinal inflammation, in gastroenteritis, Crohn's disease, ileitis or colitis, has effects on the motility (movement) of the gastrointestinal and on secretion within it. The symptoms that are recognised are poor digestion, crampy pains and diarrhoea. The symptoms often continue after the inflammation has subsided. The major disease entity that can develop after inflammation is the irritable bowel syndrome (IBS). IBS is associated with persistent disorders of bowel motility. The symptoms are triggered by changes in the properties of enteric neurons, many of which become hyperexcitable. Enteric neurons are part of the nervous system within the gut wall. However, the neurons that have changed properties after inflammation have not been identified, and the mechanisms of change are not known. This work is designed to determine the molecular basis of the changes in neuron excitability that lead to hyperexcitability. Identification of the molecules whose properties are changed will permit those molecules to be targeted in the design of compounds to treat the abnormalities of intestinal physiology that follow inflammation.Read moreRead less
The role of the immune system in pain is emerging from recent discoveries, and may hold the key to novel pain treatments. Most people experience brief gut infections from food or contagion without long-term consequences. Many others suffer symptoms for years afterwards - probably the best example of immune-based pain. Our project investigates how immune cells communicate with sensory nerves, and how these communications change from both angles after gut infection or inflammation.
Transient Receptor Potential Channels (TRPs) As Transducers And Targets In Primary Visceral Afferents
Funder
National Health and Medical Research Council
Funding Amount
$669,130.00
Summary
Transient receptor potential, or TRP channels, are involved in generating many of the sensations we perceive, such as heat, cold, touch and pain. Some TRP channels are specialized to signal pain from visceral organs, which we must investigate if we are to find treatments for visceral pain, which are currently lacking.
Identification Of The Pain Pathway From The Rectum And Its Mechanisms Of Activation
Funder
National Health and Medical Research Council
Funding Amount
$566,931.00
Summary
Abdominal pain is one of the most common reasons why patients seek medical attention. It is now known that irritable bowel syndrome (IBS) is one of the major causes of abdominal pain, but the reason why people experience pain from the gut is not known. This project will identify which sensory nerves in the gut wall signal pain to the spinal cord during conditions that mimic IBS and the precise mechanisms that activate these sensory neurons during IBS-like inflammation will be investigated.
How Does Inflammation Of The Gut Change Its Sensory Innervation?
Funder
National Health and Medical Research Council
Funding Amount
$613,767.00
Summary
A large number of patients that are referred to gastroenterologists for pain and discomfort from the bowel are offered no effective treatment. This has a large impact on quality of life and often involves invasive tests to rule out inflammatory or cancerous causes. These patients are classified as suffering from irritable bowel syndrome (IBS). Patients who have diagnosable inflammatory bowel disease (IBD) where colonoscopy is positive may suffer similar symptoms but also have no treatment for th ....A large number of patients that are referred to gastroenterologists for pain and discomfort from the bowel are offered no effective treatment. This has a large impact on quality of life and often involves invasive tests to rule out inflammatory or cancerous causes. These patients are classified as suffering from irritable bowel syndrome (IBS). Patients who have diagnosable inflammatory bowel disease (IBD) where colonoscopy is positive may suffer similar symptoms but also have no treatment for this type of symptom. It is becoming apparent that a large subgroup of IBS patients have undergone prior infection or inflammation, and that there are in fact changes in the types of cells in biopsies from their gut. Thus there are common features to IBS and inflammation. These may provide a means for us to find new treatments for IBS and IBD symptoms. Mice develop similar microscopic changes in the colon after experimental inflammation to those seen in humans, so we can discover more from this model. We have recently established that there are several types of sensory nerve fibres from the mouse colon and rectum that convey information about contractions, distension and chemical mediators released from tissue to the central nervous system. These are almost certainly responsible for generating symptoms in patients. We aim in this project to discover how these sensory nerves change in their responsiveness to mechanical and chemical stimuli in experimental inflammation. Importantly we shall investigate the mediators that are present in the tissue which may activate sensory nerves and-or the receptors on sensory nerves that may be increased. These experiments we hope will provide a target at which to aim novel drug treatments for symptoms of IBS and IBD.Read moreRead less
Identification And Characterisation Of The Genes And Pathways In Susceptibility To Inflammatory Bowel Disease
Funder
National Health and Medical Research Council
Funding Amount
$575,581.00
Summary
One of the greatest challenges facing contemporary genetics is to understand the genetics of complex diseases such as inflammatory bowel disease, mutiple sclerosis and schizophrenia. This application seeks to unravel the complex interactions between susceptibility genes and environmental triggers that work together to produce the inflammatory bowel diseases (IBD). Current estimates of the prevalence and incidence suggests that there may be 30-40,000 Australians who suffer from these chronic debi ....One of the greatest challenges facing contemporary genetics is to understand the genetics of complex diseases such as inflammatory bowel disease, mutiple sclerosis and schizophrenia. This application seeks to unravel the complex interactions between susceptibility genes and environmental triggers that work together to produce the inflammatory bowel diseases (IBD). Current estimates of the prevalence and incidence suggests that there may be 30-40,000 Australians who suffer from these chronic debiltating set of diseases known separately as Crohn's disease and ulcerative colitis. One susceptibility gene for Crohn's disease has been recently been identified and the project outlined will extend our knowledge not only to the susceptibility genes themselves, but also to the genes that interact with them to produce the disease via a cascade of immune and inflammatory events. This work is part of a large international effort to identify all IBD susceptibility genes and builds on the resources of the Australian IBD Familiy Register- an Australia wide register of families in which multiple members are affected by CD or UC. A traditional gene mapping approach is used in concert with mutiple analyses of different gene expression profiles in disease versus normal bowel tissues as well as in cell lines from patients versus controls. Validation studies include identification of the particular tissues and cell types that are involved in the pathological immune response typical of IBD as well as characterisation of specific patient genotypes and- or phenotypes that may correlate with expression profiles. Results obtained will be used to identify genes underlying IBD susceptibility, the mutations that drive the disease and eventually therapeutic targets for modulation and treatment of disease.Read moreRead less
Neural Coordination Of Intestinal Motility And Mucosal Secretion Of Water And Salt - Role In Toxin Induced Diarrhoea
Funder
National Health and Medical Research Council
Funding Amount
$490,020.00
Summary
This project deals with some of the basic mechanisms underlying disorders of gastrointestinal function and in particular with the mechanisms responsible for diarrhoea. Whenever there is a natural disaster (the recent tsunami for example) or a war, the breakdown of medical services leads to concern about outbreaks of cholera and other diarrhoea causing diseases, so understanding the mechanisms by which the cholera bacterium cause diarrhoea remains a major imperative. It is known that the diarrhoe ....This project deals with some of the basic mechanisms underlying disorders of gastrointestinal function and in particular with the mechanisms responsible for diarrhoea. Whenever there is a natural disaster (the recent tsunami for example) or a war, the breakdown of medical services leads to concern about outbreaks of cholera and other diarrhoea causing diseases, so understanding the mechanisms by which the cholera bacterium cause diarrhoea remains a major imperative. It is known that the diarrhoea resulting from cholera infection is produced by an enterotoxin, which acts to produce a massive over-secretion of water and salt through the intestinal wall, which if it is not controlled causes death by dehydration. This effect requires the activity of the nerve cells within the gut wall, the enteric nervous system (ENS). Other bacterial toxins have similar effects and also require activity of the ENS for these effects to be manifested. This project will identify how these toxins alter the activity of the ENS and the effects that they have on intestinal movements which are also regulated by the ENS. We already know that the movements and secretion of water are related to each other and that this relationship is disturbed in some more subtle diseases like irritable bowel syndrome. This project will characterise this relationship, thereby shedding light on the physiology underlying a variety of gastrointestinal disorders.Read moreRead less
Intestinal Adaptation Following Massive Small Intestinal Resection: Mechanisms And Management
Funder
National Health and Medical Research Council
Funding Amount
$256,980.00
Summary
Short bowel syndrome (SBS) remains a major clinical problem in paediatric and adult clinical practice. The Department of Gastroenterology and Clinical Nutrition at the Royal Children's Hospital has gained recognition as a national centre of excellence for the management of infants and children with SBS and intestinal failure. Due to the significant personal and heath-care burden related to SBS there has been an urgent need to improve understanding about the process of intestinal adaptation follo ....Short bowel syndrome (SBS) remains a major clinical problem in paediatric and adult clinical practice. The Department of Gastroenterology and Clinical Nutrition at the Royal Children's Hospital has gained recognition as a national centre of excellence for the management of infants and children with SBS and intestinal failure. Due to the significant personal and heath-care burden related to SBS there has been an urgent need to improve understanding about the process of intestinal adaptation following massive small bowel resection (MSBR) in order to develop new treatments aimed at improving clinical outcome for patients with SBS. Over the past 5 years we have developed a preclinical model for the study of intestinal adaptation in infants using the juvenile pig. Our recent studies in this model have revealed that elemental formula is inferior to whole protein formula suggesting that the current clinical recommendations need urgent re-evaluation. Using the preclinical model in this proposal, we aim to define the mechanisms underlying the adaptive response and evaluate novel therapies aimed at enhancing adaptation following MSBR. Supplementation of enteral feeds with bovine colostrum isolate resulted in normal growth in the preclinical model despite MSBR. In this proposal we plan to advance this observation for the first time to human clinical trials in infants with SBS. Even small gains in enteral tolerance during the early post-operative period may have a significant impact on morbidity and mortality of children with SBS due to parenteral-nutrition related liver disease and gut-related sepsis. This research proposal provides a unique link between studies aimed at providing the scientific basis for understanding the mechanisms of intestinal adaptation using an established preclinical model and translating the results of these studies onto human trials, taking advantage of the clinical expertise available in the management of children with SBS.Read moreRead less