Building An Intestine: Manipulating Regeneration Of The Epithelium
Funder
National Health and Medical Research Council
Funding Amount
$609,424.00
Summary
Diseases, infections and pathologies are common clinical problems of the intestinal lining in both infants and adults. Individuals with these conditions can experience nutritional problems and severe cases result in death. The intestinal lining is generated from a small population of stem cells. In this study we use of a mouse model where the stem cells are marked and will examine what factors regulate stem cells in the intestine with the aim of facilitating intestinal tissue regeneration.
Regulation Of Intestinal Stem Cells And Intestinal Growth
Funder
National Health and Medical Research Council
Funding Amount
$419,018.00
Summary
How the small intestine grows is important for preterm babies and those with short bowel syndrome. This study investigates the mechanisms of growth in the normal situation and in animal model of short bowel syndrome. It investigates particular growth pathways that regulate growth and particularly that of intestinal stem cells.
Spatio-temporal Analysis Of Rat Intestinal Motility In Physiological And Disease Models
Funder
National Health and Medical Research Council
Funding Amount
$358,750.00
Summary
This project addresses the question of how the movements of the gut are controlled in health and disease. The progress of food along the gut is due to movements of the involuntary muscle of the wall of the intestine. Three fundamental mechanisms are involved. One is the spontaneous ability of the intestinal muscle to contract rhythmically and is driven by a delicate net of pacemaker cells. Fast propulsion of food contents depends on nerve circuits in the gut wall that generate a powerful pumping ....This project addresses the question of how the movements of the gut are controlled in health and disease. The progress of food along the gut is due to movements of the involuntary muscle of the wall of the intestine. Three fundamental mechanisms are involved. One is the spontaneous ability of the intestinal muscle to contract rhythmically and is driven by a delicate net of pacemaker cells. Fast propulsion of food contents depends on nerve circuits in the gut wall that generate a powerful pumping behaviour to prevent over-filling or to eject toxic or irritating substances (eg: some laxatives activate this mechanisms). This is often called peristalsis. A third mechanism consists of activity of nerve cells in the gut, that slowly propagates along the intestine and causes the muscle to contract, sweeping along any remnants. The movements generated by these three mechanisms occur in segments of intestine isolated from rats. The major difficulty up until now has been to relate the actual movements in living animals to these fundamental mechanisms. It is now possible to bridge this gap because we have developed methods to record, display and measure graphically the actual movements. Movements are transformed into spatio-temporal maps which show all of the contractions over a period of time. Coordinated activity is visible in these maps as recognisable patterns or visual objects. Measurements can be readily made with conventional statistics. The literature in gastroenterology is full of descriptions of motility based on indirect methods of recordings. In this project we will be able to correlate the previous indirect methods with the new graphic methods and thus establish a clearer, simpler and more accurate classification of normal patterns of intestinal motility. We will then use this to establish what goes wrong in a number of experimental diseases known to affect adversely the movements of the intestine.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
Identification Of Genes Regulating Vertebrate Intestinal Development
Funder
National Health and Medical Research Council
Funding Amount
$465,750.00
Summary
Colorectal cancer (CRC) causes 14 per cent of all cancer deaths in Australia. While early detection improves survival rate, nearly half of all CRC patients succumb to the disease within five years. In general, metastatic CRC is resistant to chemotherapy and radiotherapy and new therapies are required. An increased knowledge of the processes that contribute to the malignant state is likely to suggest new targets for treatment. CRC, like all cancer, is the result of genetic abnormalities (mutation ....Colorectal cancer (CRC) causes 14 per cent of all cancer deaths in Australia. While early detection improves survival rate, nearly half of all CRC patients succumb to the disease within five years. In general, metastatic CRC is resistant to chemotherapy and radiotherapy and new therapies are required. An increased knowledge of the processes that contribute to the malignant state is likely to suggest new targets for treatment. CRC, like all cancer, is the result of genetic abnormalities (mutations) that are acquired over the course of a lifetime. Together the mutated genes produce changes in cell behaviour in processes such as growth, migration, angiogenesis (the ability to attract a blood supply) and cell death. All of these processes are active during normal development of a vertebrate organism, but are generally shutdown in the adult state, except in cancer. In this study, we propose to identify a set of genes that control the development of the intestine in a small tropical fish, the zebrafish. Zebrafish are vertebrate organisms, closely related to mice and man. Essentially all the pathways regulating development are conserved in the three species. The zebrafish offers several advantages: they are small, easy to breed, cheap to maintain and, most importantly, their embryos are transparent, making it possible to visualise development in live embryos in a simple microscope. Our project will use a panel of mutant strains of zebrafish that have an array of visible abnormalities in intestinal development. The abnormalities were induced using a chemical that produces single base pair changes in DNA. An established technique called positional cloning will allow us to identify the genes in which the mutations have been introduced, and provide a genetic explanation for the intestinal abnormalities. Upon identification of the mutated genes, our ultimate aim will be to test whether they also play a role in the development of CRC, using mouse models and human tissues.Read moreRead less
Novel Applications Of Ghrelin Peptides In Mouse Models Of Inflammatory Bowel Disease
Funder
National Health and Medical Research Council
Funding Amount
$243,116.00
Summary
Inflammatory bowel disease (IBD) is a debilitating, chronic condition that often affects patients in the primes of their lives. A limited number of treatments are currently available for these patients and those that are available often have serious side effects, including growth restriction in children. Ghrelin is a natural hormone that has been shown to suppress many features of IBD. This project will investigate the potential of ghrelin as a new treatment for inflammatory bowel disease.
Effects Of Ischemia/ Reperfusion Injury On Enteric Neurons And Neuroprotective Strategies
Funder
National Health and Medical Research Council
Funding Amount
$566,277.00
Summary
The intestine can suffer restricted blood flow, creating a region of damaged or dead bowel. This leads to severe medical emergencies, complications and even death. Loss of blood flow and damage can be a serious complication for intestinal transplant surgery, which compromises patient survival and recovery. The project brings together transplant surgeons and basic scientists to solve problems caused by intestinal ischemia. A major result will be to improve outcomes for Australian patients
The Role Of Transferrin Receptor, Divalent Metal Transporter, Ferroportin And Hemochromatosis Protein In Iron Absorption
Funder
National Health and Medical Research Council
Funding Amount
$195,990.00
Summary
Within Australia 1 in 300 people of Caucasian origin have a genetic defect which makes them absorb more iron from the diet than they need. Excess iron is a major problem because it damages cells and this is most obvious in the pancreas where the cells make insulin are destroyed and diabetes mellitus develop. In the liver cirrhosis and cancer often occur. Iron also accumulates in other tissues such as the heart and joints resulting in damage to these organs. The genetic defect has recently been i ....Within Australia 1 in 300 people of Caucasian origin have a genetic defect which makes them absorb more iron from the diet than they need. Excess iron is a major problem because it damages cells and this is most obvious in the pancreas where the cells make insulin are destroyed and diabetes mellitus develop. In the liver cirrhosis and cancer often occur. Iron also accumulates in other tissues such as the heart and joints resulting in damage to these organs. The genetic defect has recently been identified but how the defective protein causes the cells of the intestine to absorb more iron into the body than is needed remains unknown. This has led to the idea that the normal protein is responsible for controlling the amount of iron absorbed. Recent studies have shown a link between this protein and another called transferrin receptor. These two molecules are thought to co-operate in determining how much iron will be absorbed. Once this is determined other molecules called iron transporters are produced and these are responsible for moving the iron from the intestine into the blood. When not much iron is required only a small number of transporters are made and when more iron is required then many more are produced. How these transporters program the level of iron absorption is unknown but the process probably involves the transferrin receptor and the hemochromatosis protein. This project will investigate the function of the molecules that determine the programe for how much iron is to be absorbed, and secondly how this is linked to the production and movement of the transproters that co-ordinate this function.Read moreRead less