Mechanisms Of Intestinal And Systemic Iron Homeostasis In Early Infancy
Funder
National Health and Medical Research Council
Funding Amount
$485,835.00
Summary
Iron is essential trace element for normal health. Iron requirements are particularly high during early postnatal life to meet the needs of the growing infant. To accommodate these needs, intestinal iron absorption is extremely high at this time. We have previously shown that the iron absorption mechanism during suckling differs from that in adults and this project explores that mechanism in more detail. These studies have important implications for infant nutrition and dietary supplementation.
Sugars and non-caloric sweeteners are detected in the gut via a common sensor, which may control sugar uptake into the blood. We showed this sensor was defective in type 2 diabetic patients, which could worsen their disease. We will test if high intake of non-caloric sweeteners worsens gut control of blood glucose in healthy volunteers, and if a blocker of this sensor improves control in patients. Deep testing of this sensor will then be used to identify new drugs for managing type 2 diabetes.
The Mechanism Of Intestinal Haem Iron Absorption And Characterization Of A Novel Haem-binding Protein
Funder
National Health and Medical Research Council
Funding Amount
$537,773.00
Summary
Iron is essential for normal health as many important proteins in the body require iron to function properly (e.g. haemoglobin). However, too much iron can be toxic, so the body must keep its iron content within defined limits. The amount of iron in the body is determined at the point of absorption from the diet in the small intestine. If too little iron is absorbed, then anaemia can result. If too much iron is absorbed, as is the case in the common disease haemochromatosis (with approximately 1 ....Iron is essential for normal health as many important proteins in the body require iron to function properly (e.g. haemoglobin). However, too much iron can be toxic, so the body must keep its iron content within defined limits. The amount of iron in the body is determined at the point of absorption from the diet in the small intestine. If too little iron is absorbed, then anaemia can result. If too much iron is absorbed, as is the case in the common disease haemochromatosis (with approximately 1 in 200 Australians at risk) then the body becomes iron loaded and various organs, particularly the liver, can become damaged. An understanding of how iron is absorbed will place us in a much better position to treat diseases such as this. Iron is present in the diet in two forms - inorganic iron and haem iron. Inorganic iron is the main form of iron in foods of plant origin while most haem iron comes from meat. In a typical diet 80-90% of the iron is inorganic iron and only 10-20% is haem. Despite this, 30-50% of the iron taken into the body comes from haem, so haem iron absorption is particularly efficient. While we have learned a great deal about the mechanims by which inorganic iron is absorbed in recent years, we know very little about the absorption of haem iron, so that is the focus of this project. We will study the pathway by which haem enters the body, how this process is regulated, and the characteristics of haem binding to the cells lining the small intestine. These cells are responsible for the uptake of all nutrients from the diet. In particular, we will examine the biology of a recently identified protein known as HCP1. Preliminary evidence suggests that HCP1 could be the main protein enabling haem to be taken up by intestinal cells. These studies will enhance our knowledge of an important nutritional pathway and improve our capacity to treat diseases such as haemochromatosis where iron absorption is defective.Read moreRead less
Iron is essential in the diet but it is also toxic when present in excess, so both iron deficiency and iron overload can have significant clinical consequences. I will investigate the basic mechanisms by which the body acquires iron and how iron can lead to toxicity. The goal of these studies is to provide more effective iron supplements and to improve diagnosis and treatment of iron-related diseases. Iron metabolism in pregnancy, infants and respiratory diseases will be a particular focus.