I am a developmental lung physiologist who specialises in understanding the factors regulating normal and abnormal lung development as well as the physiological transformation of the lung into an efficient gas-exchange organ at birth.
Physical Determinants Of Lung Development Before And After Birth
Funder
National Health and Medical Research Council
Funding Amount
$442,500.00
Summary
Survival at birth is critically dependent upon the ability of the lungs to take on the role of exchanging gases; a role previously performed by the placenta. The lungs must, therefore, have grown and matured sufficiently during fetal life, before they are required at the time of birth. Inadequate development of the lungs during fetal life is the most common cause of death and disease in newborn babies. This may be due to premature birth, when the lungs have had insufficient time to develop, or i ....Survival at birth is critically dependent upon the ability of the lungs to take on the role of exchanging gases; a role previously performed by the placenta. The lungs must, therefore, have grown and matured sufficiently during fetal life, before they are required at the time of birth. Inadequate development of the lungs during fetal life is the most common cause of death and disease in newborn babies. This may be due to premature birth, when the lungs have had insufficient time to develop, or it may be due to inappropriate lung development during fetal life. It is important therefore, to understand the mechanisms that control growth and development of the lung both before and after birth. During fetal life the lungs are filled with liquid which expands the lungs and provides a stretch stimulus causing them to grow. Previously we have shown that a reduction in the degree of fetal lung expansion causes lung growth to cease. Likewise, if we increase the degree of lung expansion in the fetus, we induce a rapid increase in fetal lung growth and maturation. This stimulus is so potent that it can reverse an existing lung growth deficit, thus enabling survival of the newborn. In this application we will investigate the mechanisms by which alterations in lung expansion induce growth and maturation of the lung. Specifically we will investigate the role of calmodulin in fetal lung growth, because the genes that encode it are activated when the lung cells are growing most rapidly. In addition, we will identify other genes that are turned on or off during rapid growth of the lung because those genes are likely to play important roles in the regulation of fetal lung growth and development. We will also investigate the underlying differences in the control of lung growth at different stages of gestation, as well as investigate factors that regulate lung growth after birth, particularly in prematurely born animals.Read moreRead less
Control Of Alveolar Epithelial Cell Differentiation Before And After Birth
Funder
National Health and Medical Research Council
Funding Amount
$376,980.00
Summary
In the lung, gas exchange takes place in small terminal airsacs called alveoli. The internal surface of the alveoli are lined with 2 types of specialist cells, the type-I and type-II cells, which are essential for the normal functioning of the lung. Although both cell types look completely different and have very different functions, they are derived from the same precursor cell. However, it is not known what determines whether these cells will become a type-I or a type-II cell. This application ....In the lung, gas exchange takes place in small terminal airsacs called alveoli. The internal surface of the alveoli are lined with 2 types of specialist cells, the type-I and type-II cells, which are essential for the normal functioning of the lung. Although both cell types look completely different and have very different functions, they are derived from the same precursor cell. However, it is not known what determines whether these cells will become a type-I or a type-II cell. This application is directed towards understanding the mechanisms which determine the fate of these cells. This is critical information as the lung must have the correct proportions of both cell types to function properly as a gas exchange organ.Read moreRead less
The survival of a baby at birth is crtically dependent upon the ability of the lungs to successfully take over the role of exchanging oxygen and carbon dioxide between the air and blood. To perform this task, during fetal life the lung must have grown properly and near the end of gestation it must mature both structurally and biochemically. Thus, babies that are born early, before the expected time of birth, are born before the lungs have had the opportunity to mature. It is not surprising, ther ....The survival of a baby at birth is crtically dependent upon the ability of the lungs to successfully take over the role of exchanging oxygen and carbon dioxide between the air and blood. To perform this task, during fetal life the lung must have grown properly and near the end of gestation it must mature both structurally and biochemically. Thus, babies that are born early, before the expected time of birth, are born before the lungs have had the opportunity to mature. It is not surprising, therefore, that an inability to breathe is one of the primary problems faced by a prematurely born infant. During late gestation the lung changes dramatically in order to increase its ability to exchange gases. There is an increase in surface area and a reduction in the barrier thickness between the airspace and the blood stream. The molecular mechanisms involved in this remodelling are unknown, but it is known that the administration of corticosteroids to women at risk of preterm labour causes a large decrease in this barrier thickness and increases the distensibility of the lung. This project seeks to understand how the structure of the lung matures in late gestation and to determine whether corticosteroids regulate these changes by altering the structure of a specialised molecule, called versican. Versican resides in the tissue space outside of cells and has special properties that allow it to retain water and help organise the surrounding matrix. We propose that alterations in the structure of versican will reduce its ability to retain water, thereby reducing the tissue volume and contributing to a reduction in the air-blood tissue barrier within the lung.Read moreRead less
Fetal Responses To Intra-uterine Inflammation And The Postnatal Pulmonary Consequences
Funder
National Health and Medical Research Council
Funding Amount
$347,036.00
Summary
There is increasing evidence that exposure of the unborn baby to infection and inflammation may be the cause of several important and disabling illnesses in later life, including long-term lung injury and brain damage. Hospital-based studies have shown that infants who go on to develop these diseases have signs of inflammation before, and soon after, birth. These studies in humans, however, have only shown associations between inflammation and later disease. Carefully controlled scientific exper ....There is increasing evidence that exposure of the unborn baby to infection and inflammation may be the cause of several important and disabling illnesses in later life, including long-term lung injury and brain damage. Hospital-based studies have shown that infants who go on to develop these diseases have signs of inflammation before, and soon after, birth. These studies in humans, however, have only shown associations between inflammation and later disease. Carefully controlled scientific experiments are required to show that inflammation actually causes damage and to allow us to find ways to prevent or cure the diseases that result from such injury. In 1998, using sheep, our research group discovered a way to produce inflammation in the fetus without endangering its wellbeing or causing early labour. The inflammation is caused by injecting a sterile bacterial cell wall preparation (endotoxin) into the amniotic fluid surrounding the fetus. Using this model, we have found that an episode of inflammation before birth profoundly increases lung maturity, thus increasing the chances of survival if premature birth occurs. Based on our information from humans, we expect that if these lambs are allowed to survive past the first few days after birth, they will go on to develop chronic lung disease, and perhaps brain damage. This study will answer vital questions about the events that occur in the uterus and the fetus during periods of inflammation, and will then determine the long-term consequences in the weeks following birth. We expect that these lambs will have changes which at first will increase their chances of survival after birth, to be followed by chronic disability due to lung and brain damage. If confirmed, this finding will allow us to find treatments which can be applied before birth to ensure that children are less likely to be born with these disabling illnesses.Read moreRead less