Neuroendocrine Mechanisms By Which Leptin Regulates Reproduction
Funder
National Health and Medical Research Council
Funding Amount
$447,750.00
Summary
The reproductive system is sensitive to alterations in body weight. In particular, low body weight causes the reproductive system to cease functioning. This is because the brain 'senses' metabolic status and responds by ceasing to secrete the brain hormone that drives the reproductive process. This hormone is gonadotropin releasing hormone that acts on the pituitary gland to control the release of gonadotropins. These, in turn, act on the gonads. How the brain perceives metabolic status is not k ....The reproductive system is sensitive to alterations in body weight. In particular, low body weight causes the reproductive system to cease functioning. This is because the brain 'senses' metabolic status and responds by ceasing to secrete the brain hormone that drives the reproductive process. This hormone is gonadotropin releasing hormone that acts on the pituitary gland to control the release of gonadotropins. These, in turn, act on the gonads. How the brain perceives metabolic status is not known. Leptin is a hormone that is produced by fat and acts on the brain. This appears to be one of the means by which the reproductive system is regulated. Leptin also regulates food intake and other brain processes. Leptin acts on specific cell types in the brain. Some of these may have dual function to regulated appetite as well as reproduction. The present proposal is for work to determine mechanisms within the brain that are altered by leptin. We will also determine which specific mechanisms relate to the regulation of gonadotropin releasing hormone. The work will provide information on how putative appetite regulators might affect the reproductive axis. Such work will provide a platform for design of pharmaceutical means to manipulate the reproductive axis and will impact on the design of drugs that regulate obesity. It is possible that drugs that developed to control obesity may affect the reproductive axis and the project will identify these.Read moreRead less
Determining The Impacts Of Epigenetic Modifying Drugs On Germline Programming And Offspring Health
Funder
National Health and Medical Research Council
Funding Amount
$863,918.00
Summary
New drugs have been developed that inhibit specific enzymes that regulate epigenetic pathways in cells. These pathways significantly affect growth and development in offspring and may represent a risk to future children of patients taking the drug. This project will determine these risks and provide data for developing clinical guidelines for safe use of the drugs.
Metabolic And Molecular Determinants Of Embryo Viability
Funder
National Health and Medical Research Council
Funding Amount
$551,321.00
Summary
We know that our health as adults is influenced by the lifestyle of our mothers during pregnancy. In particular, increased risk of adult-onset diseases such as diabetes and cardiovascular disease occurs when small and lean infants at birth are raised in conditions where nutrient intake is not restricted and obesity occurs. This concept of fetal programming is now widely accepted. Our laboratory is leading research in a new concept, that of embryonic programming. We have extensive animal data dem ....We know that our health as adults is influenced by the lifestyle of our mothers during pregnancy. In particular, increased risk of adult-onset diseases such as diabetes and cardiovascular disease occurs when small and lean infants at birth are raised in conditions where nutrient intake is not restricted and obesity occurs. This concept of fetal programming is now widely accepted. Our laboratory is leading research in a new concept, that of embryonic programming. We have extensive animal data demonstrating that exposure of embryos to physiological perturbations alters fetal development, similarly to that occurring in nutrient restriction during pregnancy. Furthermore, there is data from IVF-derived children that their birth-weight is lower than expected, possibly due to the conditions used for conception in the laboratory. How does the response by eggs and embryos, at the time of conception, affect subsequent development? There has been some focus on changes to DNA that are not related to mutations, but structural changes in the DNA that alters gene expression. We call this epigenetics and epigenetic changes are found in embryos, including human embryos following IVF. However, no one knows how such epigenetic changes occur as a result of this stress response by the egg or embryo. Our proposal is to determine the mechanism of how epigenetic alterations take place in eggs and embryos. Our theory is that the mitochondria, the energy producing packages within all cells, are sending signals to the embryo's nucleus. When the egg or embryo finds itself in adverse conditions, the signals change as a result of changes in the energy balance. This in turn changes the activity of enzymes in the nucleus that regulates DNA structure. If we can prove that this relationship occurs, then we can assess these changes in human embryos that are excess to a patient's requirements and learn if programming takes place in human embryos.Read moreRead less